1. Field of the Invention
The present invention relates to a printer which records an image on a sheet medium, a setting method of the printer, and printing paper.
2. Description of the Related Art
Types of sheet medium that can be used as printing paper in a printer, for example, in an inkjet printer, have been diversified. Examples of such various types of sheet medium include printing paper that has an ink receiving layer on a printing surface thereof to improve photo image quality, thick paper such as postcards, and cloth that is printable by a printer.
An amount of ink bleeding and a condition of color development depend on the type of sheet medium. Therefore, an ink discharge amount and a number of ink discharge ports are set according to the type of sheet medium to acquire optimum image quality. In general, a user designates the type of sheet medium in a printer driver.
However, a number of options for such designation has increased along with an increase in the types of sheet medium, so that user operation has become complex. On the other hand, the printer cannot determine whether a setting is appropriate if the user has made an error in the designation due to such complexity. As a result, the printer may print in a low quality mode (i.e., a high speed mode) even if the user uses a high-grade paper that enables high quality printing. On the contrary, the ink may be excessively consumed if the printer prints on a low-grade paper in a high quality mode.
Further, when a network printer is shared by a plurality of users, there is a case where the user cannot determine which type of sheet medium is actually set in the printer. In such a case, it is necessary for the user to confirm the sheet medium that is actually set in the printer to designate the type thereof, which is an inefficient procedure.
To solve the above-described problems, U.S. Pat. No. 6,036,298 discusses a method in which the printer itself detects the type of sheet medium. More specifically, an identification mark is placed in a margin on a print side of the sheet medium, or an invisible identification mark is placed on the print side. The type of sheet medium is identified by a sensor which reads the identification mark.
In the method discussed in U.S. Pat. No. 6,036,298, the identification mark is placed on a back side of the sheet medium opposite to the print side. The sensor provided within the printer optically reads the identification mark from the print side and identifies the type of sheet medium. To realize such a method, the identification mark is required to be a clear mark which can be read from the opposite side. However, if the identification mark is too noticeable, visual quality of printing may be degraded, or the identification mark may be visible from the print side of the sheet medium after printing. On the other hand, in the conventional method, the identification mark is placed on the print side and read from the print side. The image is then printed over the identification mark, so that the image quality of the overprinted area may become degraded.
The present invention is directed to a printer that is highly practicable and can reliably detect an identification mark which may not be visually noticeable and can identify a type of sheet medium based on the detection, and further directed to a setting method of the printer and printing paper for that purpose. The present invention is further directed to a printer that can separately dispose a printing unit and a reading unit configured to read an identification mark, and realize miniaturization and high practicability.
According to an aspect of the present invention, a printer includes a printing unit configured to print on a sheet medium, a reading unit configured to read an identification mark when a sheet medium on which the identification mark is formed is used, and a control unit configured to make a print setting for printing on the sheet medium based on a read result of the reading unit, wherein the identification mark is a coded pattern drawn using a material containing a substance that scatters or absorbs ultraviolet light and containing no fluorescent substance, and wherein the reading unit includes an emitter configured to mainly emit ultraviolet light and a detector configured to detect fluorescence generated by excitation from a fluorescent whitening agent contained in the sheet medium and modulated by the pattern.
According to another aspect of the present invention, a printing paper made of a substance containing fluorescent whitening agent includes an identification mark formed on a side opposite to a print side, which is a coded pattern of information for identifying a type or a size of a printing paper, and is drawn using a material containing a substance that scatters or absorbs ultraviolet light and containing no fluorescent substance.
Further features and aspects of the present invention will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the invention and, together with the description, serve to explain the principles of the invention.
Various exemplary embodiments, features, and aspects of the invention will be described in detail below with reference to the drawings.
An exemplary embodiment of the present invention applied to an inkjet printer will be described with reference to the drawings. The present invention is applicable to a single-function printer, as well as to a multifunction peripheral which is an image reading/recording apparatus that integrally includes a plurality of functions such as a scanner function, a copy function, and a facsimile function. Further, the present invention can be applied to printers employing various methods other than the inkjet method, such as an electrophotographic method, a thermal method, and a dot impact method.
Referring to
The printer performs printing by picking up a sheet medium 3 from either of the sheet supply tray 2 or the sheet cassette 5 and supplying the sheet medium 3 to a printing unit inside the printer. A display device 6 is an input/output user interface which includes a touch panel.
In the present exemplary embodiment, the sheet supply tray 2 stores high-gloss photo paper, and the sheet cassette 5 stores plain paper as the sheet medium 3 (i.e., printing paper).
Referring to
After passing through the paper feed port 22, the sheet medium 3 moves along a common conveyance path 11. The sheet medium 3 is then nipped and conveyed by a first roller pair formed by a conveyance roller 24 and a pinch roller 23, and a second roller pair formed by a conveyance roller 26 and a pinch roller 25.
A reader 4 is disposed between the first roller pair and the second roller pair, below the common conveyance path 11. The reader 4 optically reads an identification mark formed on a back side which is opposite to the print side of the sheet medium 3. The reader 4 will be described in detail below.
The printing unit is disposed ahead of the second roller pair above the common conveyance path 11. The printing unit includes a print head 20 which employs an inkjet method, and a carriage 27 which scans the sheet medium 3 in a main scanning direction (direction perpendicular to a direction of the common conveyance path 11) while holding the print head 20. Various inkjet methods are applicable to the print head 20, such as a thermal method which uses a heating element to discharge ink, a piezoelectric method using a piezoelectric element, an electrostatic method using an electrostatic actuator, and a method using a micro electromechanical systems (MEMS) element.
In the printing unit, printing is performed by the first roller pair and the second roller pair conveying the sheet medium 3 in a direction along the common conveyance path 11 (i.e., a sub-scanning direction) while the print head 20 moves in a direction perpendicular to the sub-scanning direction (i.e., the main scanning direction). As a result, a two-dimensional image is formed on the print side of the sheet medium 3.
A discharge roller 28 and a spur 29 then discharge the sheet medium 3 on which the image is formed in a direction indicated by an arrow Z illustrated in
A controller 10 is a controlling unit which controls the entire printer.
Operations for reading the identification mark formed on the back side of the sheet medium by the reader 4, and print setting based on a read result will be described below.
The sheet medium 3 is conveyed at a constant speed along the common conveyance path 11 by the first roller pair. The reader 4 is disposed along the common conveyance path 11, facing the side opposite to the print side (i.e., the back side) of the sheet medium 3. The reader 4 reads the identification mark formed on the back side of the sheet medium 3 from the back side of the sheet medium 3 moving at the constant speed. The identification mark is drawn as a pattern in which information about a type and a size of the sheet medium 3 is coded, as will be described below.
The controller 10 identifies the information about the type, the size, or the like of the sheet medium 3 according to an output of the reader 4. Further, the controller 10 selects a print quality mode from a plurality of quality modes which are previously stored, so that the print quality (such as a method of ink impacting) appropriate for the type and size of the print medium 3 can be achieved.
The emitter 41 includes a light source (such as an ultraviolet light emitting diode (LED) or an ultraviolet laser diode (LD)) that mainly generates the ultraviolet light (of a predetermined wavelength in the range of wavelengths between 300 nm and 400 nm). The emitter 41 emits the ultraviolet light in a form of a small spot from an oblique direction on a surface of the sheet medium 3.
The detector 42 includes a light receiving element (such as a photodiode or a phototransistor). The detector 42 photo-electrically converts received light scattered in a direction proximately perpendicular to the spot on the sheet medium 3 which is irradiated with the ultraviolet light. The detector 42 does not detect directly reflected light (i.e., 0th order light) of the ultraviolet light which is indicated by a dashed arrow illustrated in
When the emitter 41 emits light (excitation light) including ultraviolet light on the sheet medium 3, fluorescence whose wavelength is different from the ultraviolet light (i.e., fluorescence in a visible light region in the vicinity of a center wavelength between 420 nm and 450 nm) is excited and generated from a fluorescent whitening agent contained in the sheet medium 3. The excited fluorescence thus enters the detector 42 together with the ultraviolet light.
If light receiving sensitivity of the light receiving element in the detector 42 is high in the visible light region, and low or nearly none in the ultraviolet light region, the detector 42 mainly detects the fluorescence and hardly detects the ultraviolet light. A wavelength selective filter can be disposed in front of the light receiving element in the detector 42, so that light with a wavelength in the vicinity of 420 nm and 450 nm is selected. As a result, the light receiving sensitivity becomes higher in the visible light (fluorescence) region compared to the ultraviolet light region.
Referring to
Referring to
The substance which “scatters or absorbs ultraviolet light” as described above is not limited to a substance that completely scatters or absorbs ultraviolet light, and can be a substance which restricts transmission of the ultraviolet light by a certain amount of scattering and absorption.
Further, the substance that “does not include a fluorescent substance” as described above is not limited to a substance that does not include any fluorescent substance. More specifically, the substance can include a small amount of fluorescent substance which generates weak fluorescence distinguishable from the fluorescence generated from the fluorescent whitening agent contained in the sheet medium 3.
Further, color of the pattern (i.e., a masking portion) of the identification mark 35 is white, which is the same as the color of the paper, or a similar color. For example, it is desirable to use a white pigment including titanium oxide microparticles or zinc oxide microparticles to form the pattern. Since titanium oxide and zinc oxide are commonly used materials, it is unnecessary to use a special ink and cost effective. Further, a white pigment can form a mark at a level that is hardly visible to the user. Furthermore, the white pigment containing titanium oxide microparticles or zinc oxide microparticles has a high affinity for ink used in the printer. Therefore, it has an advantage that the pattern is not noticeable even if the ink is applied to the pattern when two-sided printing is performed.
Returning to
As describe above, a material containing the substance that scatters or absorbs ultraviolet light and containing no fluorescent substance is applied to the paper in the masking portion 33. Actually, the white pigment is applied to the masking portion 33. On the contrary, nothing is applied to the transmitting portion 34. Therefore, if the ultraviolet light is emitted to the masking portion 33, the ultraviolet light is scattered or absorbed, so that the fluorescence is not generated or weak even if it is generated. On the other hand, if the ultraviolet light is emitted to the transmitting portion 34, the paper is irradiated with the ultraviolet light and the fluorescence is scattered by the fluorescent whitening agent.
In
It is desirable that the identification marks 35 are positioned in the vicinity of both edges of the sheet medium 3 in the longitudinal direction so that the user can set the sheet medium 3 in either orientation. In the example illustrated in
As described above, the sheet medium 3 moves at the constant speed in the sub-scanning direction to the reader 4. Therefore, an output signal which is temporally-modulated according to the pattern is acquired from the reader 4.
Referring to
The reader 4 reads the code from the output signal and acquires the information about the sheet medium 3. Such process is performed using algorithm illustrated in
Referring to
In the present exemplary embodiment, the pattern formed as a one-dimensional bar code is read while scanning. As a modified example, the pattern of the identification mark can be instantly read using an array sensor such as a charge-coupled device (CCD). In such a case, an emitting spot size of the emitter 41 in the reader 4 is set to a size which can cover the entire pattern of the identification mark. Further, an array sensor which selectively receives the fluorescence wavelength is used as the detector 42. The reader 4 thus instantly reads the fluorescence which is spatially modulated by the pattern. In this case, a two-dimensional code can be used for the pattern in addition to the one-dimensional bar code.
As described above, a reading position of the reader 4 is upstream of a recording position of the printing unit in a conveyance direction of the sheet medium 3. Therefore, the reader 4 reads the identification mark before printing is started. The controller 10 then specifies the print settings for the sheet medium to be used based on the read result. If the reader 4 detects the identification mark and identifies the type and size of the sheet medium 3, the controller 10 automatically sets the printing quality and size appropriate to the paper and performs printing.
If the identified paper is different from the paper already set by the user, the printer can request the user to confirm whether to change the setting and wait for a user instruction before printing.
Referring to
On the other hand, if the identification mark is not detected, printing is performed according to the print quality appropriate for the paper which is already set by the user or which is previously set as a default. If the user uses paper which has no identification mark on the back side, the signal output illustrated in
According to the above-described exemplary embodiment, the identification mark can be reliably detected even if the identification mark is so unnoticeable that it is hardly visible. Further, the printing unit and the reader are separately disposed above and below the common conveyance path (i.e., the sheet medium). Therefore, restriction on arrangement within the printer is small and miniaturization of the printer can be realized.
A comparison between a case where the identification mark is formed using a fluorescent substance on a sheet containing the fluorescent whitening agent with the present exemplary embodiment will be described below. If the identification mark is formed using the fluorescent substance, fluorescence is generated from both the fluorescent substance mark and the sheet when the sheet is irradiated with the ultraviolet light. As a result, a signal and noise (S/N) ratio in detection becomes deteriorated with respect to the fluorescence generated from the identification mark, which is to be originally detected.
In contrast, according to the present exemplary embodiment, the identification mark can be reliably detected by forming the pattern by masking with a material containing a substance that scatters or absorbs ultraviolet light and containing no fluorescent substance.
Therefore, according to the above-described exemplary embodiment, the identification mark on the sheet medium can be reliably detected even if the identification mark is visually unnoticeable. The type and size of the sheet medium can thus be identified based on the detection result, and apparatus settings can be specified. Accordingly, the exemplary embodiment of the present invention can provide a highly practicable printer, setting method of the printer, and printing paper.
Another exemplary embodiment of the present invention in which downsizing of the printer in the above-described exemplary embodiment can be further realized will be described below with reference to
Referring to
Since the reading position of the reader 4 is upstream of the recording position of the printing unit in the conveyance direction of the sheet medium 3, reading is performed before printing is started. Further, the reading position of the reader 4 is close to the recording position of the print head 20. Therefore, it is necessary to finish specifying print settings by reading the identification mark on the leading edge of the conveyed sheet medium 3 before the leading edge of the sheet medium 3 reaches the recording position.
It is thus desirable to dispose the identification mark at least in the vicinity of both ends of the sheet medium 3 in the longitudinal direction, so that the identification mark can be read immediately when the leading edge of the sheet medium 3 reaches the reader 4. As described above, the identification marks are disposed on both edges of the sheet medium 3 to enable handling even if either orientation thereof is set by the user.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications, equivalent structures, and functions.
This application claims priority from Japanese Patent Application No. 2008-210763 filed Aug. 19, 2008, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2008-210763 | Aug 2008 | JP | national |