Printing device and photographic paper

Abstract
A printing device, in which a vaporizable dye is thermally transcribed onto a receptor layer provided as an upper layer of a photographic paper base, with a light radiating body for whitening a color hue of a light absorbing agent of a light absorbing layer provided between a photographic paper base and a receptor layer.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




This invention relates to a printing device for printing a still picture, such as a picture formed by a video camera or a still television picture, using a vaporized dye, and a photographic paper on which printing is made by such printing device.




2. Description of the Related Art




There has hitherto been known a printing device, such as a sublimation printer, in which a sublimation ink ribbon, coated with a sublimable dye, is superposed on the photographic paper, and an electric energy corresponding to the picture information is applied to a thermal head for subliming the dye on the ink ribbon under a heat energy supplied from the thermal head for transcribing the sublimed dye onto the photographic paper.




The sublimation ink ribbon is prepared by dissolving a sublimable dye in e.g. a solution of acetate or polyester and adding a dispersant to the resulting solution to form a colloidal solution in the form of an ink which is mixed with a binder and subsequently coated on a base paper.




The photographic paper usually has a receptor layer of a heat transfer recording material on a photographic base paper. Among the heat transcription recording materials in current use is a dye-like resin, such as polyester or polycarbonate resin, admixed with a lubricant.




The thermal head is a device which translates an electrical energy into a heat energy, that is a device in which the dye is sublimed from the sublimation ink ribbon under the Joule's heat generated on flowing the current through a resistor for transcribing the sublimed dye onto the photographic paper.




When the recording picture is formed on the photographic paper by the above-mentioned sublimation ink ribbon and thermal head, the receptor layer of the photographic paper undergoes the following changes:




That is, when the heat energy is applied from the thermal head, the polyester resin, for example, of the receptor layer undergoes glass transition and softening and thereby turned into the liquid, at the same time that the dye in the sublimation ink ribbon is transferred onto the receptor layer so as to be dissolved or dispersed in the layer to form the recording picture.




With the above-described sublimation printer, in which printing is made on the photographic paper using the sublimation ink ribbon and the thermal head, it is necessary to provide an ink ribbon takeup mechanism for rewinding the ink ribbon and a heat radiating mechanism for the thermal head. On the other hand, the thermal head usually has a heat conversion efficiency of not higher than 10%, thus leading to considerable power consumption. Thus it has been difficult with the conventional sublimation type printer to realize saving in power and reduction in size and costs.




On the other hand, the sublimation ink ribbon can be used only once for each picture and hence is not economically desirable. Besides, the used-up ink ribbon cassette can not be regenerated and hence is to be discarded in a manner of not destroying the earth's environment.




Besides, the printing by such printing device is carried out by stacking dyes of yellow (Y), magenta (M).and cyan (C), so that it becomes necessary to perform three cycles of the complicated and time-consuming operations of feeding the ink ribbon, vertically moving the thermal head and feeding the photographic paper.




The thermal head generally has the line-head structure of thin resistors generated by sputtering being arranged in a line, thus the size of the printing paper cannot be set freely.




Since it is generally desirable to heat the receptor layer on the photographic paper when subliming and transcribing the sublimable dye onto the photographic paper by the thermal head, it has been a conventional practice to increase the thrusting force of the thermal head to raise the tightness of contact between the ink ribbon and the photographic paper and to apply heat to the receptor layer of the photographic paper by the thermal head. It should be noted that, if the force of thrusting the thermal head to the ink ribbon and the photographic paper is increased, the driving force necessary for the movement of the thermal head, rewinding of the ink ribbon and the feed of the photographic paper has to be correspondingly increased. In addition, since the ink ribbon is prepared by coating the dye processed into an ink on the base paper, as described above, the heat reaches the receptor layer via the base paper and the dye layer. Besides, since air layers tend to be produced between the respective layers, the heat to be applied to the receptor layer needs to be set to take account of heat losses produced in each layer, thus lowering the heat efficiency.




On the other hand, the produced picture tends to be lowered in quality if the photographic paper is not whitened at least directly after printing.




OBJECTS AND SUMMARY OF THE INVENTION




In view of the above-described status of the art, it is an object of the present invention to provide a printing device in which saving in power and reduction in size and costs may be realized without employing a thermal head or an ink ribbon. It is another object of the present invention to provide a printing device in which the printing time may be shortened and the printing paper size may be set freely to assure high picture quality of the printed picture.




It is a further object of the present invention to provide a photographic paper a receptor layer of which may be heated efficiently by the printing device to assure high picture quality of the printed picture.




According to the present invention, there is provided a printing device for thermal transcription of a vaporizable dye onto a photographic paper comprising a dye tank for containing a vaporizable dye, an entrance section for liquefying the vaporizable dye contained in the dye tank and transporting the vaporized dye, and a vaporizing section for vaporizing the liquified dye transported by the entrance section, wherein the dye vaporized by the vaporizing section is thermally transcribed onto the photographic paper.




Preferably, the vaporizable dye contained in the dye tank is powdered.




Preferably, the vaporizing section vaporizes the liquefied dye transported by the entrance section by the heat of vaporization generated responsive to a laser light.




Preferably, the laser light employed for generating the heat of vaporization in the vaporizing section is a laser light having equalized radiation intensity distribution.




Preferably, a region from the dye tank to the vaporizing section is maintained at a temperature of 50° C. to 300° C.




Preferably, the entrance section transports the liquefied dye to the vaporizing section by taking advantage of the capillary phenomenon.




Also preferably, the vaporizing section causes the vaporized dye to be deposited on the photographic paper by taking advantage of a diffusion phenomenon with the aid of beads.




According to the present invention, there is also provided a printing device for thermal transcription of a vaporizable dye onto a photographic paper comprising a containing section for containing a vaporizable dye, a supplying section for supplying the vaporizable dye supplied from the containing section, and a vaporizing section for vaporizing the vaporizable dye supplied by the supplying section under the heat of vaporization, wherein the vaporizable dye vaporized by the vaporizing section is thermally transcribed onto the photographic paper.




Preferably, the vaporizable dye contained in the containing section is a particulate vaporizable dye and the vaporizable dye supplied by the supplying section to the vaporizing section is also a particulate vaporizable dye.




Preferably, the vaporizable dye contained in the containing section is the vaporizable dye deposited on spherical-shaped bodies and the vaporizable dye supplied by the supplying section is also a vaporizable dye deposited on spherical-shaped bodies.




Preferably, the supplying section puts any excess amount of the vaporizable dye to circulation.




The supplying section may put any excess amount of the vaporizable dye to circulation with the aid of beads.




Preferably, the supplying section adds heat responsive to the laser light to the vaporizable dye as the heat of vaporization.




Preferably, the laser light employed for generating the heat of vaporization in the vaporizing section is a laser light having equalized radiation intensity distribution.




According to the present invention, there is also provided a photographic paper in which a vaporized vaporizable dye is absorbed on a receptor layer provided as an upper layer of the photographic paper base, wherein a light absorbing layer formed by a light absorbing agent is provided between the photographic paper base and the receptor layer.




Preferably, the light absorbing layer is whitened in color by thermal destruction of the light absorbing agent itself by a light radiating body in a printing device.




Preferably, the light absorbing layer is whitened in color by thermal destruction of a capsule enclosing a whitening agent therein by a light radiating body in a printing device, wherein the capsule is mixed into the light absorbing layer.




As the light absorbing agent, an infrared ray absorber capable of absorbing infrared rays may be employed. Some of the infrared ray absorbers exhibit color extinguishing characteristics.




Typical of the light absorbing agent is a functional near-IR absorption coloring matter manufactured by SHOWA DENKO KK under the trade name of IR 820B which exhibits maximum absorption for the light having a wavelength of 825 nm. If it is allowed to exist along with an ammonium salt of organic boron, such as tetrabutyl ammoniumbutyl triphenyl borate, in a solution, it absorbs the near IR rays, so that its color is extinguished.




Examples of the whitening agents include titanium oxide, zinc oxide and calcium oxide.




The capsules employed for enclosure of the whitening agents may be formed of condensates, such as polyurea or polyurethane, homopolymers such as polyethylene or polyvinyl alcohol or waxes such as paraffins or lipids.




According to the present invention, there is also provided a printing device in which a vaporizable dye is thermally transcribed onto a receptor layer provided as an upper layer of the photographic paper base, comprising a light radiating body for whitening the color of a light absorbing agent of a light absorbing layer provided between the photographic paper base and the receptor layer.




Preferably, the light emitting body radiates a laser light.




Meanwhile, the term “vaporizable dye” used in the present invention means collectively a solidified disperse dye, a liquefied disperse dye, a vaporized disperse dye, a sublimable dye and a disperse dye. Thus the vaporizable dye is defined as a dye having a temperature domain, in a temperature range of from 25° C. up to a decomposition temperature, for which temperature domain the vapor pressure is not less than 0.01 Pascal, on the provision that, if the dye molecules are associated in a gaseous phase at an average association number of


n


, the vapor pressure divided by the average number of association


n


is not less than 0.01 Pascal.




Although a sublimable dye changed from its solid state to a gaseous state may be contemplated as the vaporizable dye, a dye having the state of a liquid between a solid state and a gaseous state is also included within the meaning of the vaporizable dye.




Among a variety of the vaporizable dyes, a yellow dye, having a color index number “C. I. Disperse yellow 201”, manufactured by SUMITOMO KAGAKU KK under the trade name of “ESC-Yellow 155” and a cyan dye having a color index number “C. I. Solvent Blue 63”, manufactured by SUMITOMO KAGAKU KK under the trade name of “ESC-Blue 655” are employed in the printing device of the present invention. As a magenta dye, a tricyanomethine dye manufactured by MITSUBISHI KASEI KK under the trade name of “HSR-2031” is employed.




With the printing device according to the present invention, the dye tank stows the particulate vaporizable dye, and the entrance section liquefies the vaporizable dye and transports the thus liquefied dye to a vaporizing section, which vaporizes the liquefied dye transported by the entrance section under the heat of vaporization supplied by the laser light for transcription of the vaporized dye onto the photographic paper. The heat generating effect of the vaporizing section is improved by the laser light to enable the size of the heat radiating mechanism to be reduced. Printing becomes possible without employing an ink ribbon or a thermal head, as a result of which power saving and reduction in size and costs may be achieved. By preliminary heating within a low heat conducting material and employing the heat corresponding to the intensity of the laser light for vaporization, the heat efficiency may be improved. The degree of freedom in photographic paper size may be increased because no ink ribbon is necessitated. By providing a light absorbing layer in the photographic paper, the operating efficiency is improved. Besides, the printing time may be shortened.




It is also possible to conduct the liquefied vaporizable Y-dye to the vaporizing section by taking advantage of the capillary phenomenon with the aid of beads, or to use beads in the vaporizing section.




Since the receptor layer of the photographic paper may be heated by the laser light, the portions of the photographic paper other than the receptor layer are not affected by heat.




If the laser light has a flat light intensity distribution, the photo-thermal conversion efficiency may be improved.




With the sublimation type printing device according to the present invention, the containing section stows the particulate vaporizable dye, and the entrance section liquefies the particulate vaporizable dye and transports the thus liquefied dye to a vaporizing section, which vaporizes the liquefied dye transported by the entrance section under the heat of vaporization corresponding to the laser light intensity for transcription of the vaporized dye onto the photographic paper. In this manner, printing becomes possible without employing an ink ribbon or a thermal head so that the printing device may be reduced in size and weight. Dye exchange may be facilitated because the containing section stowing the dye therein may be dismounted and exchanged for new ones. Since the heat of vaporization corresponds to the laser light, excess heat or heat radiation is not required to enable the energy saving. Since the dye may be supplied singly, the photographic paper needs to be fed only once so that the printing time may be shortened. Free-size printing becomes possible because there is no limitation as to the photographic paper size imposed by the ink ribbon.




Besides, since the light absorbing layer formed of a light absorbing agent capable of generating heat by efficiently absorbing the light is provided between the receptor layer and the photographic paper base, the receptor layer may be heated directly to assure a high quality of the printed picture.




In addition, since a light radiating body interposed between the receptor layer and the photographic paper base of the photographic paper whitens the color of the light absorbing agent of the light absorbing layer to assure the high quality of the printed picture.




Consequently, if printing is made on the above-mentioned photographic paper by the above-mentioned printing device, the printing efficiency may be improved and the thrusting force between the dye and the receptor layer may be reduced, while resistance to abrasion may be improved. The picture quality may be improved because the light absorbing agent may be whitened in color.




If the laser light radiated by a laser block as the above-mentioned light radiating body may be of equalized light intensity distribution, it becomes possible to equalize the heat conversion occurring at the light absorbing layer of the photographic paper.




The above and other objects and advantages of the present invention will become apparent from the following description of the preferred embodiments and the claims.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view showing essential portions of a first embodiment.





FIG. 2

is a cross-sectional view showing essential portions of the first embodiment.





FIG. 3

is a perspective view showing essential portions of a vaporizable portion of the first embodiment.





FIG. 4

is a cross-sectional view showing essential portions of a first embodiment employing beads in the vaporizable portion.





FIG. 5

is a back side view showing essential portions of the first embodiment.





FIG. 6

is an illustrative view showing essential portions of the first embodiment.





FIG. 7

is a perspective view showing a typical printing mechanism for the first embodiment.





FIG. 8

is a perspective view showing essential portions of a second embodiment.





FIG. 9

is a perspective view showing a typical printing mechanism for the second embodiment.





FIG. 10

is a back side view showing a laser block provided for the printing mechanism shown in FIG.


9


.





FIG. 11

shows an arrangement of an optical system for equalizing the distribution of the laser light intensity.





FIG. 12A

is a graph showing the distribution of the laser light intensity in case of not employing the optical system shown in FIG.


11


.





FIG. 12B

is a graph showing the distribution of the laser light intensity in case of employing the optical system shown in FIG.


11


.





FIG. 13

is a perspective view showing essential parts of a third embodiment.





FIG. 14

is a perspective view showing the construction of a dye pack playing the role of a container for the third embodiment.





FIG. 15

is a cross-sectional view showing a connecting portion between a dye feed pre-stage and the dye pack playing the role of a container for the third embodiment.





FIG. 16

is a perspective view showing the dye supply pre-stage of the embodiment.





FIG. 17

is a perspective view showing an inner structure of a feed supply post-stage and the feed supply pre-stage for the third embodiment.





FIG. 18

is a schematic perspective view showing essential portions of a laser block according to the third embodiment.





FIG. 19

is a schematic perspective view showing a fourth embodiment.





FIG. 20

is a reverse side view showing a laser block for the second embodiment.





FIG. 21

is a perspective view showing a modified inner structure of a dye supply pre-stage.





FIG. 22

is a perspective view showing a fifth embodiment.





FIG. 23

is a perspective view showing a sixth embodiment.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




Referring to the drawings, preferred embodiments of the printing device and the photographic paper according to the present invention will be explained in detail.




In the first embodiment of the present invention, concerning a printing device, a vaporizable dye is employed as a dye.




The vaporizable dye collectively means a solidified disperse dyes, liquified disperse dyes, vaporized disperse dyes, sublimable dyes and disperse dyes, in which a temperature range with a vapor pressure of not lower than 0.01 pascal exists in a temperature range from 25° C. to the dye decomposition temperature. If the dye molecules are associated in the gaseous phase with one another with a mean number of association of


n


, the vapor pressure divided by the mean number of association is to be not less than 0.01 Pascal.




In the present first embodiment, among the above-mentioned vaporized dyes, a vaporized dye manufactured by SUMITOMO KAGAKU KK under a trade name of “ESC-Yellow 155” having a color index number of “C. I. Disperse Yellow 201” is employed as a yellow dye, referred to herein as Y.




As a C dye, a dye manufactured by SUMITOMO KAGAKU KK under the trade name of “ESC-Blue 655”, having a color index number of “C. I. Solvent Blue 63” is employed.




As an M dye, a tricyanomethine dye of the following chemical formula











manufactured by MITSUBISHI KASEI KK under the trade name of “HSR-2031” is employed.




With the first embodiment, the above-mentioned vaporizable dyes Y, C and M are ultimately vaporized and thermally transcribed onto the photographic paper. Therefore, a printer of the first embodiment is referred to hereinafter as a sublimation type printer.




The sublimation type printer of the first embodiment, main portions of which are shown schematically in

FIG. 1

, includes a main body


10


, formed of special high melting plastics, such as polyimide, having low heat conductivity and devoid of heat moldability, dye tanks


11


,


12


and


13


containing the above-mentioned vaporizable Y, M and C dyes in a powdery state, entrance sections


14


,


15


and


16


for dissolving the powdery dyes Y, M and C contained in the dye tanks


11


to


13


to the melting points thereof for transporting the dissolved liquified dyes, and vaporizing sections


17


,


18


and


19


for vaporizing the vaporizable dyes, dissolved and liquified by these entrance sections


14


to


16


, under the heat of vaporization supplied by a laser light beam. The vaporized dyes are deposited on a photographic paper


21


via vaporization openings, not shown, in the bottom parts of recesses or sinks


20


for dyes for each of the vaporizing sections


17


to


19


. These vaporizing sections


17


to


19


are irradiated with laser beams from laser emitting sections for dyes Y, M and C, not shown, as shown by arrows


35


,


36


and


37


, respectively. A transparent section


22


, formed of a glass material with high transmittance to permit a laser light to be transmitted therethrough without losses, is also irradiated with another laser light beam, as shown by an arrow


38


, from a laser radiating section, not shown.





FIG. 2

shows a detailed construction of a sublimation type printer according to the present first embodiment.




In

FIG. 2

, which is a sectional view showing essential portions shown in

FIG. 1

, a laser radiating portion


34


and vaporization openings


23


, not shown in

FIG. 1

, are shown. Meanwhile, since the dye tanks


11


to


13


, entrance sections


14


to


16


and the vaporizing sections


17


to


19


are each of an identical construction, only the dye tank


11


for dye Y, entrance section


14


and the vaporizing section


17


are explained herein for brevity.




The entrance section


14


and the vaporizing section


17


are associated with a first heating member


31


designed for not imparting the heat directly to the photographic paper


21


. The first heating member


31


has its one end


31




a


bent substantially vertically upwards and introduced into the dye tank


11


. The first heating member


31


has its other end


31




b


extended up to a terminal end of the vaporizing section


17


.




The vaporizable dye Y, dissolved and liquified by being heated by the end


31




a


of the first heating member


31


, referred to herein as the liquefied vaporizable dye


32


, is transported by the entrance section


14


up to the entrance section


14


. The entrance section


14


is associated with the first heating member


31


, as mentioned above. This first heating member


31


is formed e.g. of carbon or silicon compounds and capable of radiating the heat of 50° C. to 300° C. on current conduction therethrough to liquefy the vaporizable dye and to maintain the latter in the liquefied and heated state. Besides, the first heating member


31


is of a capillary construction having superficial grooves and is adapted for transporting the liquefied vaporizable dye


32


up to the vaporizing section


17


.




That is, the first heating member


31


transports the vaporizable dye


32


, liquefied under the heat e.g. of 50° C. to 300° C., as far as the vaporizing section


17


, while keeping the dye warm enough not to be solidified or thickened.




The vaporizing section


17


includes a first heating member similar to that provided in the entrance section


14


. The first heating member


31


of the vaporizing section


17


has a plurality of dye sink recesses


20


for stowing the liquefied vaporizable dye. The bottom of each dye sink recess


20


has a large number of vaporizing openings


23


which are fine through-holes each being of a diameter of several microns.




The vaporizing section


17


is provided with a second heating member, not shown, in addition to the first heating member


31


. The second heating member is formed as a layer of a semi-transparent light absorbing agent coated on the surface of the first heating member


31


and each of the dye sink recesses


20


. The second heating member is occasionally referred to herein as a light absorbing layer.




The light absorbing layer efficiently translates the laser light indicated by arrow


35


from laser emitting section


34


into heat. That is, the liquefied vaporizable dye


32


, transported by the entrance section


14


as far as the vaporizing section


17


, is heated up to the vaporizing temperature by the light absorbing layer adapted for efficiently translating the laser light indicated by arrow


35


from laser radiating section


34


into heat. The vaporized dye is transferred onto the receptor layer


21




a


of the photographic paper


21


via the vaporizing openings


23


formed in the bottom of the dye sink recesses


20


.




The concrete construction of the vaporizing section


17


is shown in FIG.


3


.




In this figure, the semi-transparent light absorbing agent, as the above-mentioned second heating member, is coated on the first heating member


31


and on the surface of the bottom of the dye sink recesses


20


.




The liquefied vaporizable dye


32


, shown in

FIG. 2

, transported as far as the vaporizing section


17


by the first heating member


31


having a trenched or grooved structure, is stowed in the dye sink recesses


20


. At this time, the laser light is radiated from the laser radiating section


34


shown in

FIG. 2

onto the dye sink recesses


20


so that the laser light is efficiently translated into heat by the light absorbing layer of the light absorbing agent for vaporizing the liquefied vaporizable dye


32


. The vaporized dye is absorbed by diffusion into the fine vaporizing openings


23


each of a diameter not larger than several microns, formed in the bottom of the dye sink recesses


20


. Since the vaporizing openings


23


are formed so as to be passed through a protective layer


33


so that the vaporized dye is transcribed by diffusion onto the receptor layer


21




a


of the photographic paper


21


shown in FIG.


2


.




Besides, part of the laser light is transmitted through the semi-transparent light-absorbing layer as far as the photographic paper


21


. Part of the light which has reached the photographic paper


21


is used for heating the receptor layer


21




a


to aid in deposition of the vaporizable dye vaporized by the vaporizing section


17


.




The operation of the sublimation type printer according to the above-described first embodiment is hereinafter summarized by referring to

FIGS. 1

to


3


.




With the sublimation type printer of the first embodiment, the vaporizable dye contained within the dye tank


11


is liquefied by being heated by the first heating member


31


of the entrance section


14


up to its melting point. The liquefied vaporizable dye


32


is transported to the vaporizing section


17


by the capillary phenomenon of the entrance section


14


. The entrance section


14


heats the liquefied vaporizable dye


32


by its first heating member


31


to keep its temperature. In addition to the first heating member


31


, which is the same as that provided in the entrance section


14


, a semi-transparent light absorbing layer as the second heating member is provided in the vaporizing section


17


for translating the laser light into heat. The vaporized dye is transferred onto the receptor layer


21




a


of the photographic paper


21


by a phenomenon of diffusion brought about by the vaporizing openings


23


in the bottom of each of the dye sink recesses


20


of the vaporizing section


17


.




The vaporizing section


17


of the sublimation type printer according to the first embodiment may also be designed for transcribing the vaporized dye onto the receptor layer


21




a


of the photographic paper


21


by the diffusion phenomenon brought about by beads, as shown in FIG.


4


.




In

FIG. 4

, the dye tank for the dye Y, as an essential portion, is shown in cross-section.




In this figure, the first heating member


43


has its one end


43




a


introduced into a dye supply opening


42


formed in the lower end of the dye tank


41


. This one end


43




a


of the first heating member


43


melts and liquefies the vaporizable dye. The liquefied vaporizable dye is supplied to the entrance section


44


. In the entrance section


44


, a number of beads


45


are arrayed along the first heating member


43


. Each bead


45


has its upper part bonded to the first heating member


43


with an adhesive and its lower end covered by a protective layer


46


. Similarly, a number of beads


45


are bonded to the first heating member


43


and to a second heating member


48


. The lower part of the beads


45


of the vaporizing section


47


are not covered. The first heating member


43


and the second heating member


48


are bonded to a base


49


.




The base


49


is transparent or otherwise formed with a through-hole in a light transmitting portion thereof for transmitting the light. Besides, it needs to be of as thin a structure as possible. To this end, a reinforcement


50


is provided on the top of the base


49


.




The adhesive employed for bonding the beads


45


, first heating member


43


and the second heating member


48


is heat resistant and transparent.




The protective layer


46


is employed for preventing intrusion of impurities or dust and dirt, so that it is formed of a material which is resistant to heat and abrasion and which is low in heat conductivity. The beads


45


are also heat-resistant and are formed of glass or a heat-resistant synthetic material.




As for the vaporizing section


47


for depositing the vaporized dye onto the photographic paper


21


by relying upon the capillary phenomenon brought about by the beads


45


, the beads


45


are arrayed along the first heating member


43


and the second heating member


48


, so that the arraying area for the beads


45


is extended as shown in

FIG. 5

which is a back side view showing the vaporizing section


47


and the entrance section


44


.




The second heating member


48


, employed in the vaporizing section


47


along with the first heating member


43


, is formed of a light absorbing material.




In the vaporizing section


47


, the second heating member


48


is surrounded in its entirety by the first heating member


43


, as shown in

FIG. 6

, which is a view similar to

FIG. 5

except that the beads


45


are not shown.




The operation of the vaporizing section


47


, employing the beads


45


, is hereinafter explained by referring to

FIGS. 4

to


6


.




The vaporizable dye contained in the dye tank


41


is heated to e.g. 50° C. to 300° C. by the first heating member


43


so as to be turned into the liquefied vaporizable dye which is then permeated through voids defined between beads


45


kept at the above temperature by the first heating member


43


. The liquefied vaporizable dye is then guided under the capillary phenomenon brought about by beads


45


to reach the vaporizing section


47


.




The liquefied vaporizable dye which has reached the vaporizing section


47


is vaporized by being heated by the second heating member


48


adapted for efficiently generating the heat by the laser light radiated from a laser generating section


51


. The dye thus vaporized is passed through voids defined by adjacent beads


45


by diffusion so as to be transcribed onto the receptor layer


21




a


of the photographic paper


21


via the lower ends of the beads


45


not covered by the protective layer


46


.




As a modification of the above-described embodiment in which the beads


45


are employed in the vaporizing section


47


, carbon compounds or light absorbing materials may be contained in or otherwise coated on the surface of the beads so that the beads


45


may simultaneously be employed as the light absorbing material for the second heating member


48


.




With the use of the beads


45


in the vaporizing section


47


, the vaporizing openings are of uniform size to assure a constant amount of vaporization of the vaporizable dye. The light absorbing agent may be coated on or contained in the beads


45


for simplifying the construction. The capillary phenomenon may be easily brought about with a material that cannot be etched. Gradation control may be facilitated by the constant amount of vaporization. Besides, the bead size may be suitably chosen for controlling the air quantity and adjusting the amount of the heat storage. The heat efficiency may be improved by combining the reinforcement with base


49


. Intrusion of dust and dirt or impurities may be inhibited by coating an area other than the vaporizing openings with the protective layer


46


. The beads may be used simultaneously as the wear-resistant layer in contact with the photographic paper


21


to simplify the construction.




An illustrative example of a printing mechanism employing the sublimation type printing device according to the above-described first embodiment is explained by referring to FIG.


7


.




The printing mechanism includes vaporizing units


51


,


52


each consisting in a laser emitting unit built into a sublimation type printer of the first embodiment the essential part of which is shown in FIG.


1


. The two vaporizing units


51


,


52


are of identical construction comprising dye layers


11


,


12


and


13


, entrance sections


14


,


15


and


16


, vaporizing sections


17


,


18


and


19


, four laser radiating sections and a transparent section


22


.




These vaporizing units


51


,


52


are connected to signal lines


53


,


54


and are moved by a vaporizing unit feed shaft


55


and a vaporizing unit supporting shaft


56


in the vaporizing unit feed direction indicated by arrow L.




The photographic paper


21


is fed by a photographic paper driving roll


57


in the paper feed direction indicated by arrow N. The vaporizing units


51


,


52


and the photographic paper


21


are pressed into tight contact with each other by a vaporizing unit supporting roll


58


.




The photographic paper


21


is introduced into a space between the vaporizing units


51


,


52


and the vaporizing unit supporting roll


58


. With the printing mechanism shown in

FIG. 7

, the two vaporizing units


51


,


52


are provided for printing in two sections, with the vaporizing unit being fed in one line. The vaporizable dyes Y, M and C are simultaneously heated and melted by the heating members within the vaporizing units


51


,


52


so as to be turned into liquefied vaporizable dyes.




The vaporizable dye liquefied in the vaporizing units


51


,


52


is heated by the laser light beams associated with picture signals from the Y, M and C laser radiating units so as to be turned into the vaporized dye which is transcribed onto the receptor layer


21




a


of the photographic paper


21


.




After completion of one-line printing, the photographic paper


21


is fed by one-line length by a photographic paper driving roll


57


. Printing is started sequentially for each color and performed in a similar manner after the third dot.




A second embodiment concerning a printing device according to the present invention is hereinafter explained by referring to FIG.


8


.




Each dye employed in the present second embodiment is similar to the sublimable dye employed in the sublimation type printer according to the first embodiment. Since the vaporizable dyes Y, C and M of the present second embodiment are also ultimately vaporized and thermally transcribed onto the photographic paper, the present device is referred to herein as a sublimation type printer according to the second embodiment.




The sublimation type printer according to the second embodiment, essential parts of which are shown schematically in

FIG. 8

, includes dye tanks


61


,


62


and


63


containing powdered vaporizable dyes Y, M and C, entrance sections


64


,


65


and


66


for liquefying the vaporizable dyes supplied from the vaporizing sections


61


to


63


and transporting the liquefied dyes and vaporizing sections


67


,


68


and


69


for vaporizing the vaporizable dyes liquefied by these entrance sections


64


to


66


by the vaporizing heat supplied by the laser light from laser light emitting means, not shown. The vaporizable dye is transcribed onto the photographic paper


21


via the vaporizing openings formed in the vaporizing sections


67


to


69


. It is noted that a plurality of each of the vaporizing sections


67


to


69


are provided along each of the entrance sections


64


to


66


. For example, a number of the vaporizing sections


67


corresponding to the number of dots of a picture are provided along the line direction of the photographic paper shown by arrow L in FIG.


8


. The same is true of the vaporizing sections


68


and


69


.




The operation of the sublimation type printer according to the second embodiment is explained in connection with the dye tank


61


, entrance section


64


and the vaporizing sections


67


shown in FIG.


8


.




A first heating member


71


at the entrance section


64


heats the vaporizable dye in the dye tank


61


so that the vaporizable dye is turned into a liquefied vaporizable dye. The entrance section


64


transports the liquefied vaporizable dye up to the vaporizing sections


67


under a capillary phenomenon as in the case of the sublimation type printer of the previously explained first embodiment.




The liquefied vaporizable dye from the dye tank


61


is transported by the entrance section


64


onto the plural vaporizing sections


67


which are sequentially irradiated with the laser light radiated by laser radiating means, not shown. That is, the first heating member


71


of the entrance section


64


liquefies the vaporizable dye contained in the dye tank


61


at its one end and transports the liquefied vaporizable dye as far as the vaporizing sections


67


by its capillary structure provided by the beads or flutes as it maintains the temperature of 50° C. to 300° C. of the dye to prevent its solidification.




The vaporizing sections


67


are also provided with the first heating member


71


similar to that provided for the entrance section


64


. Each vaporizing section


67


is provided with a plurality of fine vaporizing openings each being of a diameter of several microns. Besides the first heating member


71


, a second heating member


72


is also provided for the vaporizing sections


67


. The second heating member is a light absorbing layer formed by coating a semi-transparent light absorbing agent on the first heating member


71


and the vaporizing openings. The second heating member efficiently translates the laser light from a laser radiating section, not shown, into heat, so that the vaporizable dye introduced into the vaporizing sections


67


is vaporized so as to be transcribed onto the receptor layer of the photographic paper via the vaporizing openings formed in the vaporizing sections


67


. The same construction is employed for the dye tanks


62


,


63


, entrance sections


65


,


66


and the vaporizing sections


68


,


69


.




Besides, since the light absorbing layer is semi-transparent, part of the light which has reached the photographic paper


21


is used for heating its receptor layer


21




a


to aid in deposition of the vaporizable dye vaporized by the vaporizing sections


67


.




An illustrative example of a printing mechanism employing the sublimation type printer according to the second embodiment is hereinafter explained by referring to FIG.


9


.




This printing mechanism comprises a sublimation type printer of the second embodiment, the essential portions of which are shown schematically in

FIG. 8

, and a pair of movable laser blocks


82


,


83


of identical construction for radiating the laser light on the laser block


81


for printing. The sublimation type printer is secured in position as a head block.




Each of the laser blocks


82


,


83


, the reverse side of which is shown in

FIG. 10

, has a laser light outgoing opening


89




a


for Y printing, a laser light outgoing opening


89




b


for M printing, a laser light outgoing opening


89




c


for C printing and a laser light outgoing opening


89




d


for the photographic paper. These laser blocks


82


,


83


are connected to a signal line


84


for laser light and is moved by a laser block feed shaft


85


and a laser block supporting shaft


86


in the line direction as indicated by arrow L. At this time, the laser light outgoing opening


89




a


for Y printing, the laser light outgoing opening


89




b


for M printing and the laser light outgoing opening


89




c


for C printing are positioned directly above the vaporizing sections


67


,


68


and


69


of the head block


81


, respectively.




The photographic paper


21


is fed by paper driving rolls


87


in the paper feed direction indicated by arrow N. The photographic paper


21


is pressed by the paper supporting roll


88


into intimate contact with the head block


81


.




The photographic paper


21


is inserted into a space between the head block


81


and the supporting roll


88


. The vaporizing sections


67


,


68


and


69


are arrayed in alignment with the printing direction indicated by arrow N, with the number of each of the vaporizing sections


67


to


69


along the line direction indicated by arrow L being the same as the number of pixels. The laser light radiating openings in the laser blocks


82


,


83


are set so as to be in register with the vaporizing sections


67


,


68


and


69


of the head block


81


in the paper feed direction or printing direction and arrayed at a rate of the number of the openings to the number of the vaporizing sections


67


to


69


of the head block


81


in the line direction of 1:1 or 1:1/n. If the laser light radiating openings are arranged at a number rate of 1:1 with respect to the vaporizing sections in the head block


81


, the laser radiating openings may be provided in the laser block


81


. Even if the laser light radiating openings are arranged at a number rate of 1:n with respect to vaporizing sections in the head block


81


, the laser radiating openings may be provided in the laser bloc


81


at a number rate of 1/n.




The vaporizable dyes Y, M and C are heated simultaneously by the first heating member within the head block


81


so as to be turned into the liquefied vaporizable dye.




The vaporizable dyes, liquefied by the vaporizing sections


67


,


68


and


69


within the head block


81


, are additively heated by the laser light beams corresponding to the picture signals from the laser blocks


82


,


83


so as to be transcribed onto the receptor layer


21




a


of the photographic paper


21


via the vaporizing openings which provide for dye diffusion. If the laser radiating openings are provided at the number rate of 1/n with respect to the vaporizing sections, the laser blocks


82


,


83


are moved in the line direction indicated by arrow N for completing the printing for one line. The same operation is performed for each of the dyes M and C. The printing for three lines at the start and end of printing is made sequentially and that for the remaining lines is performed simultaneously for the Y, M and C dyes. On completion of printing for one line, the photographic paper


21


is fed by one line by the photographic paper driving roll


87


.




Thus, with the present sublimation type printer according to the present second embodiment, the head block


81


, provided with a plurality of each of the vaporizing sections


67


to


69


, is fixed, while the laser blocks


82


,


83


, having the laser radiating openings thereof aligned with the vaporizing sections


67


to


69


, are moved and the vaporizable dyes, liquefied by the laser light beams @@Corresponding to the picture signals, are additively heated and vaporized for transcription on the photographic paper.




Meanwhile, each vaporizing section of the sublimation type printer according to the second embodiment may also be arranged in accordance with the principle of the capillary phenomenon brought about by beads.




It should be noted that, if a laser light is radiated on the vaporizing sections of the sublimation type printer according to the first or second embodiment after being equalized in intensity in the laser generating section and in the laser blocks over its range of distribution, heat transformation in the light absorbing layer may be equalized and, besides, the energy transformation efficiency may be maximized.




If a semiconductor laser having a light distribution in which the energy density becomes higher towards its mid portion is radiated onto a light absorbing layer is provided in close proximity thereto, a non-uniform thermal energy having only poor efficiency as the energy used for transcribing the dye is produced. Besides, since the energy density is high at the mid region, the receptor layer of the photographic paper onto which the dye is transferred tends to be dissolved or even scorched under the high heat. Also, in view of the angle of light diffusion, the distance between the light source and the an object receiving the light tends to be limited. In addition, because of the non-uniform light distribution, the density of transcription tends to be thicker and thinner towards the mid region and towards the rim portion of the photographic paper, respectively.




It may be contemplated to expand the light distribution of the laser light from the laser light source by a diffusion plate or a concave lens for providing a uniform light distribution on the irradiated surface. That is, it suffices to diminish the degree of concentration towards the mid region in the above-described energy distribution to relax the light concentration to provide a flat light distribution.





FIG. 11

shows an optical system for generating a laser light having an equalized range of distribution of laser light intensity.




Referring to

FIG. 11

, showing such optical system, a laser light radiated from a semiconductor laser


91


is collimated by a collimator lens


92


which is converted into diffused light by e.g. a flat plate micro-lens


93


of a fine micro-lens array construction. The diffused light is then caused to fall on a convex lens


94


which condenses the diffused light to radiate a light having a uniform light intensity distribution onto a light absorbing layer. In this manner, the light distribution similar to a Gaussian distribution, as shown in

FIG. 12A

, is converted into a trapezoidal light distribution as shown in FIG.


12


B.




Therefore, if the distribution of irradiation of the laser light, employed for generating the heat of vaporization at a vaporizing section, is equalized by the optical system shown in

FIG. 11

, the light energy may be converted into a heat energy at a high efficiency. Besides, the use of the above-described optical system leads to a uniform transcription density and coloration with high resolution. The distance between the light source and the irradiated member may be set freely. Besides, a suitable size of coloration may be achieved depending on the manner of designing of the optical system and the semiconductor laser power.




A third embodiment of the present invention concerning the printing device is hereinafter explained by referring to FIG.


13


.




In the present third embodiment, a particulate vaporizable dye, consisting in a mixture of the vaporizable dyes Y, M and C as used in the sublimation type printer of the first or second embodiment and a dispersant compatible with the vaporizable dyes, such as a volatile binder, is employed and vaporized so as to be transcribed under heat onto the photographic paper. For this reason, the third embodiment is referred to herein as a sublimation type printer according to the third embodiment.




The sublimation type printer according to the third embodiment, shown schematically in

FIG. 13

, comprises a dye pack


110


having separate tanks for the particulate Y, M and C dyes, a dye supply pre-stage section


120


for shifting the particulate vaporizable dyes from the dye pack


110


in one predetermined direction, a dye supply post-stage section


140


for receiving the particulate vaporizable dye from the pre-stage section


120


, a vaporizing section, not shown, for receiving and vaporizing the particulate vaporizable dye supplied from the post-stage section


140


, a laser block


150


for radiating a laser light onto the vaporizing section for generating the heat of vaporization therein, a paper feed roll


102


for feeding a photographic paper


21


in a direction shown by arrow N so that the vaporized dye is transcribed thereon, and a photographic paper tray


103


for storing a roll of the photographic paper


21


.




Referring to

FIG. 14

, the construction of the dye pack


110


is first explained.




The dye pack


110


has three separate tanks, that is a Y-tank


111


, an M-tank


112


and a C-tank


113


, in which the above-mentioned particulate vaporizable dyes Y, M and C are stored, respectively. The dye pack


110


is dismountable for exchange and has a hermetically sealed structure to prevent intrusion of humidity or foreign matter or vaporization of the dyes under the effect of ambient light. However, the dye pack


110


also has a fine pore area


114


to permit air venting.




As the dye pack


110


is secured to the dye supply pre-stage section


120


shown in

FIG. 3

by set screws


104




a


to


104




d


, the particulate vaporizable dyes are fed onto the dye supply pre-stage section


120


via a Y-dye outlet


115


, an M-dye outlet


116


and a C-dye outlet


117


, each in the form of protrusions, provided on the bottom of the pre-stage section


120


.




These dye outlets


115


to


117


, in the form of protrusions, are introduced into a Y-dye reception opening


121


, an M-dye reception opening


122


and a C-dye reception opening


123


, formed in the dye supply pre-stage section


120


shown in FIG.


13


. This state is shown in the cross-sectional view of FIG.


15


. Although only the structure of a connecting portion between the Y-dye outlet


115


shown in FIG.


14


and the Y-dye receiving opening


121


shown in

FIG. 13

is shown in the cross-sectional view in

FIG. 15

, the same structure is used for connecting portion between the M-dye outlet


116


and the C-dye outlet


117


and that between the C-dye outlet


117


and the M-dye outlet


123


.




First, a simplified resilient valve


115




b


is provided at a tubular portion


115




a


of the dye outlet


115


to permit the dye pack


110


to be hermetically sealed under the usual condition of the dye pack in which the dye pack is not mounted onto the dye supply pre-stage section


120


. A spring section


124


and a lid


125


having a conical portion


125




b


formed with flutes


125




a


is provided in the vicinity of the dye receiving opening


121


of the dye supply pre-stage section


120


to permit the pre-stage section


120


to be hermetically sealed under the usual condition in which the dye pack


110


is not mounted in position on the pre-stage section


120


.




When the dye pack


110


is mounted on the pre-stage section


120


, the lid


125


fitted with the conical portion


125




b


formed with the flutes


125




a


is thrust upwards for opening slit-shaped openings


118


and


127


formed in the pre-stage section


120


and the dye outlet


115


. At this time, the conical portion


125




b


of the lid


125


formed with the flutes


125




a


thrusts the valve


115




b


at the dye outlet


15


open, so that the particulate vaporizable dye contained in the dye pack


110


descends along the flutes


125




a


of the lid


125


which has thrust open the valve


15




b


of the dye outlet


115


. The dye is then guided via the slit-shaped openings


118


,


127


towards the dye supply pre-stage section


120


. A resilient member


126


is mounted in the vicinity of the dye supply pre-stage section


120


for maintaining a hermetically sealed structure after connection of the pre-stage section


120


to the dye pack


110


. The flutes


125




a


may be designed to allow passage only of the particulate dye having a size not larger than a predetermined size.




Referring to

FIGS. 16 and 17

, the constructions of the dye supply pre-stage, the dye supply post-stage section


140


and vaporizing sections are hereinafter explained.




The dye supply pre-stage section


120


separately receives the particulate vaporizable dyes Y, M and C, separately contained in the Y-tank


111


, M-tank


112


and in the C-tank


113


of the dye pack


110


, shown in

FIG. 14

, in its Y-dye supply pre-stage section


128


, M-dye receiving pre-stage section


129


and in the C-dye receiving pre-stage section


130


, respectively, by virtue of the connection between the Y-dye outlet


115


, M-dye outlet


116


and the C-dye outlet


117


of the dye pack


110


, on one hand, and the Y-dye receiving opening


121


, M-dye receiving opening


122


and the C-dye receiving opening


123


, on the other hand. The particulate vaporizable dyes Y, M and C, supplied to the Y-dye supply pre-stage section


128


, M-dye receiving pre-stage section


129


and the C-dye receiving pre-stage section


130


, are rollingly moved along the direction shown by arrow E.




Such rolling movement of the particulate vaporizable dyes Y, M and C is rendered possible by the internal structure of the dye supply pre-stage section


120


as shown in

FIG. 17

, in which the internal structure of the Y-dye supply pre-stage section


128


, M-dye supply pre-stage section


129


and the C-dye supply pre-stage section


130


is shown with a lid


120




b


of the pre-stage section


120


detached from a casing section


120




a.






The Y-dye supply pre-stage section


128


, M-dye receiving pre-stage section


129


and the C-dye receiving pre-stage section


130


are provided with feed screws


134


,


135


and


136


, respectively, which are formed in shafts


131


,


132


and


133


, respectively. These feed screws


134


to


136


are rotated about their own axes by a rotational torque which the shafts


131


to


133


receive from a gear


105


, shown in

FIG. 16

, which is rotated under a driving force of feeding the photographic paper


21


. Thus the particulate vaporizable Y-dye


137


, for example, is rollingly moved in the direction shown by arrow E in FIG.


16


.




The particulate vaporizable Y-dye, for example, is fed onto the dye supply post-stage section


140


via through-holes


138


. The internal structure of the post-stage section


140


is also shown in FIG.


17


.




The dye supply post-stage section


140


is formed by stacking a plate


140




a


, formed of a glass material having low light absorbance and a low heat conductivity, on a plate


141


formed with a number of slits


148


, each being several p microns in diameter. The post-stage section


140


also includes a Y-dye supplying patterned groove


142


, about 50 to 80 pm deep, for conducting the particulate vaporizable dye


137


fed via the through-holes


140


. An M-dye supplying patterned groove


143


and a C-dye supplying patterned groove


144


are formed in a similar manner. These grooves


142


,


143


and


144


are each formed with a plurality of vaporizing sections


145


,


146


and


147


, respectively.




The particulate vaporizable Y-dye


137


is fed in a direction shown by arrow F in the Y-dye supplying groove


142


, for example, so as to be stored in the vaporizing section


145


. The laser light transmitted through a lid


140




b


formed of a glass material exhibiting high transmittance is radiated on the particulate vaporizable Y-dye


137


stored in the vaporizing section


145


.




Each of the vaporizing sections


145


to


147


, irradiated with the laser light from a laser block


150


via the lid


140




b


, absorbs about one half of the volume of the laser light to transform it into heat for vaporizing the dye. The remaining one-half of the laser light is used for heating the reception layer on the photographic paper


1


.




The dye vaporized by the vaporizing sections


145


to


147


is permeated towards below through the vaporizing openings


148


formed in the plate


141


under the capillary phenomenon so as to be transcribed on the receptor layer of the photographic plate


21


.




Each of the particulate dyes which has not been stowed in the vaporizing sections


145


to


147


, that is not vaporized, is circulated via the grooves


142


,


143


and


144


of the dye supply post-stage section


140


to the dye supply pre-stage section


120


.




The, laser block


150


is explained by referring to FIG.


18


.




The laser block


150


has its arms


151


,


152


,


153


and


154


secured to a base section


161


. Each of these arms


151


to


154


is provided with a plurality of semiconductor laser devices so that several laser light beams


155


,


156


,


157


and


158


are radiated simultaneously from these arms


151


to


154


in a downward direction, that is towards the vaporizing sections


145


,


146


and


147


.




The driving of the laser block


150


in the direction of arrow G is controlled by e.g. a rotary actuator


159


, such as an electric motor, so that the laser block is advanced and receded each in e.g. three stages via an offset cam


160


. The driving of the rotary actuator


159


is carried out in a timed relation to the Y, M and C color signals.




The driving of the laser block


150


in the direction of arrow H is controlled e.g. by a feed mechanism or by a linear motor. This enables the number of the laser devices to be reduced to lower the costs and to improve the yield. The driving in the direction of arrow H or in the transverse direction is carried out in a timed relation to the color dot signals.




With the sublimation type printer according to the third embodiment, the particulate vaporizable dyes Y, M and C, contained in separate tanks of the dye pack


110


, are transported in one direction by the dye supply pre-stage section


120


up to the vaporizing sections


145


,


146


and


147


of the dye supply post-stage


140


, so as to be vaporized in the vaporizing sections


145


,


146


and


147


by the vaporizing heat corresponding to the laser light for transcription onto the photographic paper


21


. Thus there is no necessity of providing an ink ribbon or a thermal head and the device may be reduced in size while dye exchange may be facilitated. Besides, any excess dye left in the vaporizing sections


145


,


146


and


147


may be circulated for achieving saving to assure printing with high picture quality.




Referring to

FIG. 19

, a fourth embodiment of the present invention concerning the printing device is explained.




In the present fourth embodiment, similarly to the above-described third embodiment, the particulate vaporizable dye is employed and vaporized so as to be thermally transcribed onto the photographic paper. Thus the device of the present fourth embodiment is hereinafter referred to as a sublimation type printer according to the fourth embodiment.




Although the dye pack in the sublimation type printer is not shown in

FIG. 19

showing the schematic arrangement of the printer, the construction of the printer and the manner of feeding the dye to the dye supply pre-stage section


171


, corresponding to the dye supply pre-stage section


120


according to the third embodiment, is similar to the sublimation type printer according to the third embodiment. Besides, the manner of transporting the dye within the dye supply pre-stage section


171


is similar to that performed with the sublimation type printer according to the third embodiment.




With the sublimation type printer according to the fourth embodiment, a head block


170


, comprised of a dye pack, not shown, the dye supply pre-stage section


171


and a dye-supply post-stage section


172


having a vaporizing section, not shown, is fixed, and laser blocks


173


,


174


, for radiating the laser light onto the head block


170


, are moved for performing the printing on the photographic paper


21


. The laser blocks


173


,


174


are of identical construction.




The laser blocks


173


,


174


, the back sides of which are shown in

FIG. 20

, are each formed with Y-printing laser outgoing openings


176




a


, M-printing laser outgoing openings


176




b


, C-printing laser outgoing openings


176




c


and outgoing openings for a laser for photographic paper


176




d


, and are connected to a signal line for laser


175


. The laser blocks


173


,


174


are moved by a laser block feed shaft


177


and a laser block supporting shaft


178


so as to be moved in the line direction as indicated by an arrow L. At this time, the Y-printing laser outgoing openings


176




a


, M-printing laser outgoing openings


176




b


, C-printing laser outgoing openings


176




c


and the outgoing openings for laser for photographic paper


176




d


of the laser blocks


173


and


174


are positioned directly above the vaporizing sections formed in the dye supply post-stage section


172


of the head block


170


.




Referring to

FIGS. 19 and 20

, the operation of the sublimation type printer according to the present fourth embodiment is hereinafter explained.




The photographic paper


21


is fed by a photographic paper driving roll


179


is the paper feed direction shown by arrow N. The photographic paper


21


is pressed by a printing paper supporting roll


180


into intimate pressure contact with the head block


170


.




The photographic paper


21


is introduced into a space between the head block


170


and the photographic paper supporting roll


180


. The vaporizing sections of the head block


170


are arrayed in alignment with the printing direction indicated by arrow N, with the number of each of the vaporizing sections in the head block


170


along the line direction indicated by arrow L being the same as the number of pixels. The laser light radiating openings in the laser blocks


173


,


174


are set so as to be in register with the vaporizing sections in the paper feed direction or printing direction, and are arrayed at the number rate of 1:1 or 1:1/n in the line direction. If the laser light radiating openings are arranged at the number rate of 1:1 with respect to the vaporizing sections, the laser radiating openings may be provided in the laser block


170


. Even if the laser light radiating openings are arranged at the number rate of 1:n with respect to the head block


170


, the laser radiating openings may be provided in the laser block at the number rate of 1/n.




The vaporizable dyes in the vaporizing sections within the head block


170


are vaporized by the laser light corresponding to picture signals from the laser blocks


173


and


174


so as to be transcribed onto the photographic paper


21


. If the number of the laser radiating openings bears a ratio of 1/n with respect to the number of the vaporizing sections, the laser blocks


173


,


174


are moved in the line direction indicated by arrow N a distance corresponding to the number of pixels to complete one line. The same operation is performed for the dyes M and C. The Y, M and C dyes are printed sequentially for three printing start and end lines and simultaneously for the remaining lines. After the end of printing for one line, the photographic paper


21


is fed by one line by the printing paper driving roll


179


.




Thus, with the sublimation type printer according to the present fourth embodiment, since the head block


170


is fixed, and the laser blocks


173


,


174


, having the respective laser radiating openings aligned with the vaporizing sections, are moved, for vaporizing the particulate vaporizable dyes, moved in one direction by the dye supply pre-stage section


171


, by the laser light corresponding to the picture signals, for transcription onto the photographic paper


21


, there is no necessity of providing an ink ribbon or a thermal head, so that the device may be reduced in size. Besides, dye exchange may be simplified. In addition, since any excess dye left in the vaporizing sections


145


,


146


and


147


may be circulated for achieving the saving in the dye to assure the printing with high picture quality.




It is noted that, with the sublimation type printers according to the third and fourth embodiments, the particulate vaporizable dye is contained in the dye pack and used in circulation. Alternatively, the particulate vaporizable dye contained in the dye pack may also be deposited in the dye supply pre-stage section on the surfaces of spherical-shaped beads, each being several microns in diameter, so as to be moved in one direction for being supplied to the vaporizing sections formed in the dye supply post-stage section. The dye may also be circulated in the manner as described above.




The beads, on the surfaces of which the particulate vaporizable dye is deposited, may also be moved in one direction by transverse vibrations as shown in FIG.


21


. In such case, the particulate vaporizable dye supplied from the dye pack, herein not shown, via dye reception openings


191


,


192


and


193


is moved through the inside of the dye supply pre-stage section


190


by a transverse oscillation generating device


194


, so as to be supplied to a dye supply post-stage section


200


having the vaporizing sections formed therein. The transverse oscillation generating device


194


generates transverse oscillation by a shaft


195


. Shafts


196


,


197


are also the shafts for generating transverse oscillation in transverse oscillation generating devices, not shown, having the same construction as the transverse oscillation generating device


194


.




The beads, on the surfaces of which the particulate or powdered vaporizable dye is deposited, may also be moved by pneumatic feed means, in a manner not shown.




On the other hand, if the laser light radiated on the sublimation type printers according to the third and fourth embodiments is radiated in each laser block with equalized intensity distribution, as in the case of the sublimation type printer according to the first and second embodiments, it becomes possible to equalize the transformation into heat in the light absorbing layer and to maximize the energy conversion efficiency.




Meanwhile, with the sublimation type printers according to the first to fourth embodiments, the vaporized dye is deposited on the photographic paper


21


for printing. In any of these embodiments, the receptor layer on the surface of the photographic paper


21


may be heated to aid in deposition of the vaporized dye.




Referring to

FIGS. 22 and 23

, fifth and sixth embodiments of the present invention, relating to the photographic paper capable of heating the receptor layer efficiently, will be explained. In the following, the fifth and sixth embodiments are referred to as a photographic paper according to the fifth embodiment and a photographic paper according to the sixth embodiment, respectively.




Referring first to

FIG. 22

, the photographic paper according to the fifth embodiment includes, looking from the upper side, a receptor layer


211


which is formed of a resin, such as cellulose resin, and which is capable of transmitting the light therethrough and absorbing the vaporizable dye, a light absorbing layer


212


formed of a light absorbing agent capable of efficiently absorbing the laser light and generating the heat efficiently, a first protective layer


213


formed of a highly heat-resistant and non-hygroscopic material, such as polypropylene, a photographic paper base


214


formed e.g. of polyethylene terephthalate, and a second protective layer


215


having properties similar to those of the first protective layer


213


and playing the role of not causing the warping of the photographic paper of the fifth embodiment


210


, these layers


211


to


215


being bonded and stacked one upon the other with the aid of an adhesive, not shown.




The receptor layer


211


absorbs the dye vaporized under the heat of vaporization generated by a laser light from a printing device, not shown. That is, a semi-transparent heating member, provided within a vaporizing section of the printing device, not shown, generates the heat efficiently by the laser light to vaporize the vaporizable dye. The vaporized dye is released via the vaporizing openings provided in the vaporizing section so as to be deposited on the receptor layer


211


.




Part of the laser light is transmitted through the semi-transparent heating member so as to be radiated on the photographic paper


210


. Since the receptor layer


211


formed on the surface of the photographic paper transmits the light, the laser light reaches the light absorbing layer


212


.




The light absorbing layer


212


is formed e.g. of a light absorbing agent, such as an IR absorber, and hence absorbs the laser light efficiently, so that heat may be generated efficiently. The heat generated in the light absorbing layer


212


is transmitted to the receptor layer


211


and tends to be transmitted to the first protective layer


213


. However, since the first protective layer


213


is formed of a highly heat-resistant and low heat conducting material, such as polypropylene, it is transmitted only to the receptor layer


211


without being transmitted to the first protective layer


213


. Thus the receptor layer


211


is heated efficiently by the light absorbing layer


212


.




In general, the light absorbing agent, used for absorbing the light, reflects the light if the agent has a white hue. For this reason, the light absorbing layer


212


has a pale color hue, instead of a white hue. Such color hue of the light absorbing layer


212


deteriorates the quality of the printed picture. For this reason, the light absorbing layer


212


needs to be whitened after printing. For whiting the light absorbing layer


212


after printing, the light absorbing agent, such as the above-mentioned IR light absorber, which has its color extinguished on irradiation with a laser light, is employed.




As such light absorbing agent, a functional near-infrared ray absorbing coloring matter, manufactured by SHOWA DENKO KK under the trade name of IR 820B, is employed. This functional near-infrared ray absorbing coloring matter IR 820B, exhibits an absorption maximum for the light having a wavelength of 825 nm, such that, if it is used along with an ammonium salt of organic boron, such as tetrabutyl ammoniumbutyl triphenyl borate, in a solution, it absorbs the near infrared rays to extinguish the color.




Thus, with the photographic paper


210


of the fifth embodiment, the receptor layer


211


may be directly heated by the light absorbing layer


212


, while the pale color of the light absorbing layer


212


is extinguished by the laser light, so that the printed picture is not degraded in picture quality.




The construction of the photographic paper according to the sixth embodiment of the present invention is explained.




The construction of the photographic paper according to the sixth embodiment shown in

FIG. 23

is approximately similar to that of the above-described first embodiment shown in

FIG. 22

, so that similar parts or components are depicted by the same numerals and the corresponding description is omitted for simplicity.




The photographic paper


220


of the present sixth embodiment includes, looking from the upper side, a receptor layer


211


, a light absorbing layer


221


, a first protective layer


213


, a photographic paper base


214


and a second protective layer


215


, bonded and stacked together with the aid of an adhesive, not shown, applied between the adjacent layers.




The light absorbing layer


221


efficiently absorbs a laser light, not shown, for generating the heat efficiently, as in the case of the photographic paper of the fifth embodiment. The receptor layer


211


is heated by the light absorbing layer


221


.




With the photographic paper


220


according to the sixth embodiment, a capsule having an enclosed whitening agent is destroyed by the laser light for permeating the whitening agent for whitening the light absorbing layer


221


.




That is, the light absorbing layer


221


contains a light absorbing agent and a whitening agent, such as titanium oxide, enclosed in a number of capsules


222


formed e.g. of polyurea, as shown in FIG.


23


. The capsule


222


is thermally destroyed by the laser light for permeating the whitening agent into the light absorbing agent for extinguishing the color of the light absorbing agent for whitening the light absorbing layer


221


.




The whitening agents may be enumerated by titanium oxide, zinc oxide or calcium oxide.




The capsule for enclosing the whitening agent may be formed of condensates, such as polyurea or polyurethane, homopolymers such as polyvinyl alcohols or waxes, such as paraffin or lipid.




Thus, with the photographic paper


220


of the present sixth embodiment, the receptor player


211


may be heated directly by the light absorbing layer


221


to assure a high heat efficiency, while the light absorbing layer


221


is whitened by the whitening agent which is distributed on thermal capsule destruction to maintain a high picture quality of the printed picture.




With the use of the photographic paper according to the fifth or sixth embodiment, the light absorbing layer


211


or


221


of the photographic paper


210


or


220


may be whitened by the laser light which has its output increased by employing a transparent section of vaporizing sections


51


,


52


, corresponding to the transparent section


22


in

FIG. 1

, if the above-mentioned typical printing mechanism shown in

FIG. 7

provided with the sublimation printer according to the first embodiment is employed. In such case, the laser light employed in the vaporizing sections


51


,


52


is of a four-beam construction.




With the illustrative printing mechanism, provided with the sublimation type printer according to the above-mentioned second embodiment, as shown in

FIG. 9

, a laser light which has its output increased is radiated after the end of printing on the transparent section of the head block


81


, corresponding to the transparent section


70


of

FIG. 8

, via the laser radiating opening


89




d


for photographic paper formed in the laser locks


82


,


83


, for whitening the light absorbing layers


211


or


221


of the photographic papers


210


or


220


, respectively.




With the sublimation type printer according to the third embodiment, shown in

FIG. 13

, the light absorbing layers


211


or


221


of the photographic paper


210


or


220


may be whitened by one-half of the laser light from the laser block


150


.




With the sublimation type printer according to the fourth embodiment, shown in

FIG. 19

, the light absorbing layers


211


or


221


of the photographic paper


210


or


220


may be whitened by radiating a laser light of an increased output via the laser radiating opening for photographic paper


176




d


formed in the laser block


173


or


174


after the end of printing.




Referring to

FIGS. 8 and 9

, the operation of the sublimation type printer of the second embodiment up to the whitening of the light absorbing layer


211


or


221


is explained.




With the sublimation type printer according to the second embodiment, the vaporizable dye contained in e.g. the dye tank


61


is liquefied or melted by being heated by the first heating member


71


of the entrance section


64


. The vaporizable dye thus liquefied is moved by the capillary phenomenon of the entrance section


64


onto the vaporizing section


67


. The entrance section


64


heats the liquefied vaporizable dye by the first heating member and maintains its temperature. The liquefied vaporizable dye, moved onto the vaporizing section


67


, is vaporized under the heat of vaporization from the second heating member which efficiently generates heat by the laser light radiated from the laser block


82


or


83


. The vaporized dye is passed through the vaporizing openings in the vaporizing section


67


by the diffusion phenomenon so as to be deposited on the receptor layer


211


or


211


of the photographic paper


210


or


220


. At this time, the light absorbing layers


211


or


221


of the photographic paper


210


or


220


is heated by the laser light transmitted through the semi-transparent second heating member of the vaporizing section


67


for heating the receptor layer


211


or


211


to aid in transcription of the vaporized dye. Subsequently, the laser light transmitted through the transparent section


70


thermally destroys the light absorbing agent of the light absorbing layer


211


or


221


or the capsules,


222


enclosing the whitening agent for whitening the color hue of the light absorbing layer


211


or


221


. The order of the intensity or temperature of the laser light may be expressed by (the laser light for dye transcription)<(laser light for heating the receptor layer)<(laser light for whitening the light absorbing layer).




It is noted that the photographic paper according to the present invention is not limited to the above-described fifth and sixth embodiments. For example, the receptor layer, light absorbing layer, first protective layer, photographic paper base and the second protective layer may be formed of materials different from those given above if these layers are endowed with the properties required of them. The same may be said of the light absorbing agents, whitening agents or capsules provided in the light absorbing layer.




The whitening of the light absorbing layer may also be realized by the combination of thermal destruction of the light absorbing agent and thermal destruction of the whitening agent enclosing capsules brought about by the laser light.



Claims
  • 1. A printing device in which a vaporizable dye is thermally transcribed onto a receptor layer provided as an upper layer of a photographic paper base, comprising:a light radiating body for whitening a color hue of a light absorbing agent of a light absorbing layer provided between said photographic paper base and said receptor layer.
  • 2. The printing device as claimed in claim 1, wherein said light radiating body radiates a laser light.
  • 3. A printing device as claimed in claim 2, wherein said light radiating body is of a four-beam construction.
  • 4. A printing device as claimed in claim 3, wherein three beams of said four-beam construction are for printing, and a fourth beam of said four-beam construction is for the whitening of the color hue of said light absorbing agent of said light absorbing layer provided between said photographic paper base and said receptor layer.
  • 5. A printing device as claimed in claim 3, which further comprises a head block, wherein three beams of said four-beam construction correspond respectively to three vaporizing sections of said head block, and a fourth beam of said four-beam construction is for the whitening of the color hue of said light absorbing agent of said light absorbing layer provided between said photographic paper base and said receptor layer.
  • 6. A printing device as claimed in claim 2, which further comprises a laser block, wherein one half of light radiated from said laser block is for the whitening of the color hue of said light absorbing agent of said light absorbing layer provided between said photographic paper base and said receptor layer.
  • 7. A printing device as claimed in claim 1, wherein the printing device is provided with a sublimation-type printer.
Priority Claims (3)
Number Date Country Kind
4-30587 Oct 1992 JP
4-300588 Oct 1992 JP
4-277165 Oct 1992 JP
Parent Case Info

This application is a divisional application of Ser. No. 09/340,157, filed Jun. 28, 1999, now U.S. Pat. No. 6,126,284, which is a divisional application of Ser. No. 08/661,380, filed on Jun. 11, 1996, now U.S. Pat. No. 6,012,800, which is a continuation of Ser. No. 08/134,677, filed Oct. 12, 1993 now U.S. Pat. No. 5,594,480 of Shuji SATO, et al., entitled PRINTING DEVICE AND PHOTOGRAPHIC PAPER.

US Referenced Citations (1)
Number Name Date Kind
4745043 Hirai May 1988 A
Continuations (1)
Number Date Country
Parent 08/134677 Oct 1993 US
Child 08/661380 US