Liquid spraying apparatus

Information

  • Patent Grant
  • 6622934
  • Patent Number
    6,622,934
  • Date Filed
    Tuesday, February 23, 1999
    25 years ago
  • Date Issued
    Tuesday, September 23, 2003
    21 years ago
Abstract
When a liquid tank of a liquid spraying apparatus is filled with a liquid, after the liquid has been supplied into the spray tank of the liquid spraying apparatus, if the existence of residual bubbles is detected by a bubble detecting device, an operation is carried out in which the liquid inside the spray tank is drained so as to drain out the bubbles from the tank and the spray tank is refilled with a liquid. As a result, residual bubbles inside the spray tank are removed from the spray tank and the liquid can be applied appropriately to a photosensitive material without causing atomization failure.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to a liquid spraying apparatus which sprays an image forming solvent as a liquid onto image recording materials such as a photosensitive material and an image receiving material.




2. Description of the Related Art




Generally, an image forming apparatus using a laser exposure heat developing and transferring system (i.e., a silver salt photographing system) is used. In such an image forming apparatus, prints are output in the processing steps as shown in FIG.


14


. First, in an exposure processing step, image processing is carried out on an image data input signal by a CPU


500


. The signal which has been subjected to the image processing is transmitted to a semi-conductor unit


502


.




In this semi-conductor unit


502


, by using a laser (LD) light source, a three-color simultaneous exposure process is carried out on the exposure surface of a donor piece


506


which has been pulled out from a donor roll


504


onto which a donor material is wound in the form of a roll, and cut to a predetermined length. By this exposure process, silver halide contained in the donor piece


506


reacts with the light source, a static image is formed, and fed to a water application step.




In this water application step, a predetermined, small amount of water is uniformly applied to the surface of the donor piece


506


by a liquid spraying apparatus


508


, and the donor piece


506


having water thus applied thereto is fed to a heat developing and color image transferring step.




In this heat developing and color image transferring step, in a state in which an image receiving paper strip


512


(an OHP film or the like can also be used) which has been pulled out and cut to a predetermined length from an image receiving paper roll


510


, and the donor piece


506


onto which water is applied are laminated with each other, the laminated image receiving paper strip


512


and the donor piece


506


are heated by a heating device


514


. Therefore, a developing process is carried out on the donor piece


506


, while dyes on the donor piece


506


are transferred to the image receiving paper strip


512


, and fixed thereto. Accordingly, an image on the donor piece


506


is transferred to the image receiving paper strip


512


. After this transferring operation has been completed, the laminated image receiving paper strip


512


and donor piece


506


are fed to a peel-off step.




In this peel-off step, the donor piece


506


which has been used, and the image receiving paper strip


512


onto which an image has been transferred are peeled off from each other, the donor piece


506


is then abandoned, and the image receiving paper strip


512


is finished as a high quality color print, and thereby outputted.




Conventionally, as a liquid spraying apparatus


508


which is used for such an image forming apparatus as described above, a liquid spraying apparatus has been proposed. In this apparatus, in order to uniformly apply a small amount of water to the surface of the donor piece


506


, a nozzle plate in which a number of small nozzle holes are punched is disposed at the bottom of a sealed water tank to which water is supplied from outside. A small columnar actuator is provided at a predetermined distance from the nozzle plate in the lengthwise direction thereof. The nozzle plate is vibrated by driving the actuator, the water in the water tank, as water droplets, is sprayed from the nozzle holes of the nozzle plate to the outside.




In the above-described liquid spraying apparatus


508


, at the beginning of use of the apparatus, water is supplied from a water supplying pipe and the internal portion of an empty water tank is filled with the water. During the operation of spraying water onto the donor piece


506


, the same amount of water is supplied from the water supplying pipe to the sealed type water tank as that lost each time it is sprayed so that the water pressure in the tank can be kept constant. Further, when the operation of applying water to the donor piece


506


by means of the liquid spraying apparatus


508


has been completed, water in the water tank is drained from a drain pipe so that water leakage from the nozzle holes is prevented when the liquid spraying apparatus


508


is not in use.




In such a liquid spraying apparatus which has been proposed conventionally as described above, during use thereof, when an empty water tank is filled with water, the internal wall of the water tank may be deposited with bubbles, and some of these may remain as residual bubbles.




In this way, if residual bubbles exist inside the sealed type water tank, when the nozzle plate is vibrated by driving the actuator, and the nozzle plate moves in the direction in which the pressure in the water tank increases, the volume of the bubbles contracts so as to absorb the pressure in the water tank. Or when the nozzle plate moves in the direction in which the pressure in the water tank decreases, the volume of the bubbles expands so as to absorb the pressure in the water tank. Accordingly, pressure loss is caused. As a result, there are drawbacks in that the pressure for pressurizing the water in the sealed type water tank by the nozzle plate decreases, water cannot be pushed out and sprayed from the nozzle holes, and atomization failure may be caused.




SUMMARY OF THE INVENTION




In view of the aforementioned facts, it is an object of the present invention to provide a liquid spraying apparatus in which, when a liquid tank having a nozzle plate is filled with a liquid, the internal portion of the liquid tank is prevented from being deposited with residual bubbles, and a liquid can be sprayed appropriately from the liquid tank without causing atomization failure.




In accordance with a first aspect of the present invention, there is provided a liquid spraying apparatus in which a nozzle plate, which is provided at a portion of the wall surface of a spray tank which stores a liquid therein, and which has a row of nozzles made up of a plurality of nozzle holes through which a liquid is sprayed, is reciprocated so that the liquid inside the spray tank is pressurized and sprayed from the plurality of nozzle holes, comprising: a bubble detecting means which, when the spray tank is filled with a liquid, detects whether residual bubbles exist inside the spray tank.




Since the present invention is structured as described above, at the start of using the liquid spraying apparatus, when the spray tank is filled with a liquid, if residual bubbles exist inside the spray tank, the bubble detecting means detects that residual bubbles exist in the spray tank. In this case, for example, by a user performing a manual operation in which a liquid is drained from the spray tank so as to drain out residual bubbles therefrom and the spray tank is refilled with a liquid, residual bubbles are removed from the spray tank, and without causing atomization failure, a liquid can be sprayed appropriately from the spray tank.




In accordance with a second aspect of the present invention, there is provided a liquid spraying apparatus in which a nozzle plate, which is provided at a portion of the wall surface of a spray tank which stores a liquid therein, and which has a row of nozzles made up of a plurality of nozzle holes through which a liquid is sprayed, is reciprocated so that the liquid inside the spray tank is pressurized and sprayed from the plurality of nozzle holes, comprising: bubble detecting means which, when the spray tank is filled with a liquid, detects whether or not residual bubbles exist inside the spray tank; and residual bubble prevention and control means which, when receiving a signal indicating that the existence of residual bubbles has been detected by the bubble detecting means, drains the residual bubbles.




Since the present invention is structured as described above, after the spray tank has been filled with a liquid, when the existence of residual bubbles has been detected by the bubble detecting means, a control operation in which the liquid inside the spray tank is drained so as to drain out residual bubbles, and the spray tank is refilled with a liquid is automatically carried out. Alternatively, a control operation comprising: means in which residual bubbles are removed by tilting the spray tank; means in which residual bubbles are removed by decreasing the pressure of the liquid with which the spray tank is filled; and means in which residual bubbles are removed by stirring the liquid with which the spray tank is filled, and the like are carried out automatically. As a result, residual bubbles are removed from the spray tank, and a liquid can be sprayed appropriately from the spray tank without causing atomization failure.




In accordance with a third aspect of the present invention, there is provided a liquid spraying apparatus in which a nozzle plate, which is provided at a portion of the wall surface of a spray tank which stores a liquid therein, and which has a row of nozzles made up of a plurality of nozzle holes through which a liquid is sprayed, is reciprocated so that the liquid inside the spray tank is pressurized and sprayed from the plurality of nozzle holes, comprising: bubble detecting means which, when the spray tank is filled with a liquid, detects whether or not residual bubbles exist inside the spray tank; and residual bubble prevention and control means which, when receiving a signal indicating that the existence of residual bubbles has been detected by the bubble detecting means, carries out a control operation in which the liquid with which the spray tank is filled is drained, and the spray tank is refilled with a liquid.




Since the present invention is structured as described above, after the spray tank has been filled with a liquid, when the existence of residual bubbles has been detected by the bubble detecting means, a control operation is automatically performed in which the liquid with which the spray tank is filled is drained, and the spray tank is refilled with a liquid. As a result, residual bubbles are removed from spray tank, and a liquid can be sprayed appropriately from the spray tank without causing atomization failure.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a schematic overall structural view of an image recording apparatus having a liquid spraying apparatus according to an embodiment of the present invention.





FIG. 2

is a schematic overall structural view of an application device using the liquid spraying apparatus according to the present embodiment.





FIG. 3

is an enlarged perspective view of the liquid spraying apparatus according to the present embodiment.





FIG. 4

is an enlarged perspective view of another example of the structure of the liquid spraying apparatus according to the present embodiment.





FIG. 5

is a flowchart which illustrates a control operation of a controller in the image recording apparatus having the liquid spraying apparatus according to the present embodiment.





FIG. 6

is a cross sectional view taken along line VI—VI in FIG.


3


.





FIG. 7

is a cross sectional view taken along line VI—VI in

FIG. 3

at the time of liquid spraying.





FIG. 8

is a bottom view of the liquid spraying apparatus according to the present embodiment and illustrating the state in which a liquid is sprayed onto a photosensitive material which is being conveyed.





FIG. 9

is an enlarged view of a heat developing and transferring section in the image recording apparatus having the liquid spraying apparatus according to the present embodiment.





FIG. 10

is a schematic cross sectional explanatory view illustrating a first example of the structure of a bubble detecting means in the liquid spraying apparatus according to the present embodiment.





FIG. 11

is a schematic cross sectional explanatory view illustrating a second example of the structure of a bubble detecting means in the liquid spraying apparatus according to the present embodiment.





FIG. 12

is a schematic cross sectional explanatory view of a third example of the structure of a bubble detecting means in the liquid spraying apparatus according to the present embodiment.





FIG. 13

is a schematic cross sectional explanatory view of a fourth example of the structure of a bubble detecting means in the liquid spraying apparatus according to the present embodiment.





FIG. 14

is a view illustrating a treatment processes in an image recording apparatus having a conventional liquid spraying apparatus.











DESCRIPTION OF THE PREFERRED EMBODIMENTS




A schematic overall structural view of an image recording apparatus


10


as an image forming apparatus having a liquid spraying apparatus according to an embodiment of the present invention is shown in FIG.


1


.




A photosensitive material magazine


14


which receives a photosensitive material


16


therein is disposed in a housing


12


of the image recording apparatus


10


which is shown in FIG.


1


. The photosensitive material


16


is taken up in the photosensitive material magazine


14


in the form of a roll such that the photosensitive (exposure) surface of this photosensitive material


16


which has been pulled out from the photosensitive material magazine


14


faces towards the left of the diagram in FIG.


1


.




A pair of nip rollers


18


and a cutter


20


are provided near a photosensitive material output port in the photosensitive material magazine


14


, and can cut the photosensitive material


16


, which has been pulled out from the photosensitive material magazine


14


, to a predetermined length. The cutter


20


is, for example, a rotary type cutter formed of a moving blade and a stationary blade. The cutter


20


can cut the photosensitive material


16


by vertically moving the moving blade via a rotating cam or the like so as to mesh with the stationary blade.




A plurality of pairs of conveying rollers


24


,


26


,


28


,


30


,


32


, and


34


are sequentially provided on the downstream side of the cutter


20


in the direction in which the photosensitive material


16


is conveyed. A guide plate (not shown) is provided between each of the pairs of the conveying rollers. The photosensitive material


16


which has been cut to a predetermined length is conveyed firstly to an exposure section


22


provided between the pairs of conveying rollers


24


and


26


.




An exposure device


38


is provided at the left side of the exposure section


22


, and three types of LDs, a lens unit, a polygon mirror, and a mirror unit are disposed therein (none of which is shown). A light beam C is transmitted to the exposure section


22


from the exposure device


38


for the photosensitive material


16


to be exposed.




Further, above the exposure section


22


, are provided a U-turn portion


40


through which the photosensitive material


16


is conveyed by being curved into a U-shape, and a water application section


50


which applies an image forming solvent to the photosensitive material


16


. In accordance with the present embodiment, water is used as the image forming solvent.




The photosensitive material


16


, which has come up from the photosensitive material magazine


14


and which has been exposed at the exposure section


22


, is nipped and conveyed by each of the pairs of the conveying rollers


28


and


30


, and is fed to the water application portion


50


through the conveying path above the U-turn portion


40


.




As shown in

FIG. 2

, a spray tank


312


which forms a part of an application device


310


which is a liquid spraying apparatus is disposed at a position which is opposite to the conveying path A of the photosensitive material


16


inside the water application section


50


.




Further, as shown in

FIG. 2

, a water bottle


332


for storing the water which is supplied into the spray tank


312


is disposed at the lower left side of the spraying tank


312


, and a filter


334


for filtering the water is disposed at an upper portion of the water bottle


332


. A water supplying pipe


342


, which has a pump


336


disposed midway thereof, connects the water bottle


332


and the filter


334


.




Further, a sub-tank


338


for storing water which is supplied from the water bottle


332


is disposed at the right side of the spray tank


312


, and a water supplying pipe


344


extends from the filter


334


to the sub-tank


338


. Therefore, when the pump


336


is operated, water is supplied from the water bottle


332


to the filter


334


, and the water, which has already passed through the filter


334


and been filtered, is supplied into the sub-tank


338


and is temporarily stored therein. A water supplying pipe


346


, which connects the sub-tank


338


and a side end portion of the spray tank


312


, is disposed therebetween. The spray tank


312


is filled with water which has been pumped from the water bottle


332


by the pump


336


, through the filter


334


, the sub-tank


338


, the water supplying pipe


346


, and the like.




A tray


340


, which is connected to the water bottle


332


via a circulation pipe


348


, is disposed beneath the spray tank


312


. The tray


340


accumulates water overflowing the spray tank


312


and returns the water into the water bottle


332


via the circulation pipe


348


. Further, the circulation pipe


348


is connected to the sub-tank


338


in a state where the circulation pipe


348


projects and extends into the sub-tank


338


. The circulation pipe


348


returns the excessive water which has been accumulated in the sub-tank


338


into the water bottle


332


.




As shown in

FIGS. 6 and 8

, a nozzle plate


322


made by an elastically deformable, rectangular, and thin plate member (e.g., a thickness of 60 μm or less) is disposed at a portion which is a bottom wall surface of this spray tank


312


and opposes the conveying path A of the photosensitive material


16


.




Further, as shown in

FIGS. 6

to


8


, this nozzle plate


322


has a plurality of nozzle holes


324


(each of which has a diameter of 10 μm to 200 μm, for example) for spraying water, with which the spray tank


312


has been filled. The nozzle holes


324


form a straight line on this nozzle plate


322


so as to be spaced apart from each other at a predetermined distance along a direction crossing the conveying direction A of the photosensitive material


16


, and are disposed so as to extend along the entire widthwise direction of the photosensitive material


16


. The plurality of the nozzle holes


324


can be disposed or structured in a single or a plurality of rows. Accordingly, water inside the spray tank


312


is able to be discharged from each of the nozzle holes


324


towards the photosensitive material


16


.




In order to increase the rigidity of the nozzle plate


322


in the longitudinal direction thereof in which the plurality of the nozzle holes


324


form a straight line, a groove portion


322


A is provided at the nozzle plate


32


. The groove portion


322


A extends along the direction in which the plurality of the nozzle holes


324


form a straight line, and is formed so as to be bent in a trapezoidal cross sectional concave shape.




Due to the water pressure when water is stored inside the spray tank


312


, the water overflowing the nozzle holes


324


is connected between the nozzle holes adjacent to each other. The apparent diameter of a nozzle hole becomes larger so that water leakage may be caused. In order to prevent such water leakage as described above, a water repelling treatment using NiP plating or the like is applied to the bottom surface of the nozzle plate


322


, i.e., the external side surface of the spray tank


312


.




In order to prevent the deposition of bubbles at the peripheries of the nozzle holes


324


, the corner portions of the nozzle plate


322


which are disposed on the internal side of the spray tank


312


and at the peripheries of the nozzle holes


324


are formed in a curved cross sectional configuration, or a hydrophobic treatment is applied thereto.




As shown in

FIGS. 2 and 3

, an exhaust pipe


330


extends from the upper portion of the spray tank


312


on the opposite side to the portion where the water supplying pipe


346


is connected. The exhaust pipe


330


connects the outside and inside portions of the spray tank


312


. A valve (not shown) for opening or closing this exhaust pipe


330


is provided midway on the exhaust pipe


330


, and the spray tank


312


can be opened or closed to the outside air by the opening or closing movement of this valve.




Both end portions of the nozzle plate


322


, being the end portions of the nozzle plate


322


which are positioned in an orthogonal direction with respect to the direction of the row of nozzles made up of the plurality of nozzle holes


324


arranged in a line, are bonded with an adhesive or the like respectively to a pair of lever plates


320


, which serve as displacement transmitting members, as is shown in FIG.


6


. Through this adhesive bonding, the nozzle plate


322


and the pair of lever plates


320


are connected to each other. The pair of lever plates


320


are fixed respectively to a pair of sidewalls


312


A through supporting portions


312


B which are sidewalls for connecting the pair of sidewalls


312


A of the spray tank


312


.




A portion of each of a pair of topwalls


312


C, abutting each other and forming the top surface of the spray tank


312


, protrudes to the outside of the spray tank


312


. A plurality of piezoelectric elements


326


serving as actuators (in this embodiment, two piezoelectric elements are provided on each side) which are extended and driven are bonded and disposed at the lower side of each of these projecting topwalls


312


C. The external end side of each of the lever plates


320


is bonded to the lower surface of each of the piezoelectric elements


326


, and the piezoelectric elements


326


and the lever plate


320


are connected to each other. Namely, the piezoelectric elements


326


are installed so as to span the distance between the topwalls


312


C and the lever plates


320


.




Therefore, a lever mechanism can be structured by these piezoelectric elements


326


, the lever plates


320


, and the supporting portions


312


B. When the external end sides of the lever plates


320


are moved by the piezoelectric elements


326


, the lever plates


320


are moved so as to be swingable around the supporting portions


312


B, and the internal end sides of the lever plates


320


are moved in the opposite direction of this movement. These piezoelectric elements


326


are formed from, for example, laminated piezoceramics. The displacements of the piezoelectric elements in the axial direction are made larger. The piezoelectric elements are connected to a power supply in which the timing of application of a voltage is controlled by a controller (none of which is shown). The aforementioned valve for opening or closing the exhaust pipe


330


is also connected to this controller. The controller controls the opening or closing movement of the valve.




Each of the lever plates


320


, the sidewalls


312


A, the supporting portions


312


B, and the topwalls


312


C forms a part of the frames


314


integrated with each other. As shown in

FIG. 6

, the pair of frames


314


are overlapped and fastened by unillustrated bolts, and the external frame of the spray tank


312


is thereby formed in a state in which each of the pair of lever plates


320


, the pair of sidewalls


312


A, the pair of topwalls


312


C, and the pair of supporting portions


312


B are disposed so as to face each other.




The frames


314


are made from metallic materials such as aluminum, brass, magnesium, and the like. Further, as is shown in

FIG. 6

; the specific sizes of the lever plates


320


and the supporting portions


312


B are such that each of the lever plates


320


has a thickness D which ranges from 2 mm to 8 mm, the thickness t of a hinge being the width of each of the supporting portions


312


B ranges from 0.2 mm to 1 mm, and the height H of a hinge which is the height of each of the supporting portions


312


B ranges from 0.6 mm to 3 mm.




Each of the lever plates


320


itself needs high rigidity so as to move integrally and swingably as a rigid body, and has the thickness D of 2 to 8 mm. Further, if each of the supporting portions


312


B has a hinge thickness t which is excessively thin, it becomes difficult to manufacture the supporting portions


312


B and it becomes easy to cause a breakage to the same. If each of the supporting portions


312


B has a hinge thickness t which is excessively thick, it becomes difficult for the lever plates


320


to move. Further, if each of the supporting portions


312


B has a hinge height H which is excessively high, it becomes easy for the supporting portions


312


B to fall down. However, provided that the supporting portions


312


B and the lever plates


320


have the above-described range of sizes, such problems as described above are not caused.




By forming the lever plates


320


and the supporting portions


312


B within the above-described range of sizes, the magnification of the lever mechanism, which is the ratio of the displacement amount of the nozzle plate


322


at the peripheries of the nozzle holes


324


with respect to the displacement amount of the piezoelectric elements


326


, can range from 1 time to 20 times.




As shown in FIG.


3


and

FIG. 8

, thin sealing plates


328


are disposed at portions partitioned by both end portions of the nozzle plate


322


, being the end portions of the nozzle plate


322


which is positioned in the longitudinal direction with respect to the direction of the row of the nozzle holes


324


arranged in a line, and by the end portions of the pair of frames


314


and are disposed in a state in which the respective thin sealing plates


328


are bonded to the pair of frames


314


.




In order to prevent water leakage through the gaps between the longitudinal end portions of the nozzle plate


322


and the end portions of the pair of frames


314


, and the sealing plates


328


, the internal portions of the sealing plates


328


are filled with an elastic adhesive such as a silicone rubber adhesive or the like. Accordingly, without inhibiting the movements of the end portions of the nozzle plate


322


, the gaps in the spray tank


312


may also be sealed with the elastic adhesive. Further, the end portions of the spray tank


312


can be sealed with caps formed from an elastic adhesive without using the thin sealing plates


328


.




As described above, when power is supplied to the piezoelectric elements


326


, as shown in

FIG. 7

, the piezoelectric elements


326


are extended so that the lever plates


320


are rotated around the supporting portions


312


B. In accordance with this, the nozzle plate


322


is displaced while being deformed by the piezoelectric elements


326


such that the central portion of the nozzle plate


322


rises in the direction of arrow B. In accordance with the deformation of the nozzle plate


322


, water pressure inside the spray tank


312


increases, and water droplets L comprising small amounts of water are sprayed linearly from the nozzle holes


324


at the same time.




By repeatedly supplying power to the piezoelectric elements


326


and by repeatedly extending the piezoelectric elements


326


, water droplets L can be sprayed successively from the nozzle holes


324


.




A bubble detecting means in the liquid spraying apparatus according to the present embodiment, and a control method thereof will be explained hereinafter. In this liquid spraying apparatus


508


, during use of the image forming apparatus, the spray tank


312


is filled with water, and after the use of the image forming apparatus, water is drained from the spray tank


312


, and while the image forming apparatus is not in use, the spray tank


312


stands by.




For this reason, at the start of using the image forming apparatus, the spray tank


312


is filled with water. However, if residual bubbles exist inside the spray tank


312


, even when the piezoelectric elements


326


of the liquid spraying apparatus are driven and the nozzle plate


322


is thereby deformed, and the volume inside the spray tank


312


is reduced by a very small amount and water is thereby pushed out from the nozzle holes


324


, residual bubbles existing inside the spray tank


312


collapse, and the very small amount by which the volume inside the spray tank


312


has been reduced due to the deformation of the nozzle plate


322


is thereby absorbed. As a result, because water droplets are not appropriately sprayed from the nozzle holes


324


, atomization action in the liquid spraying apparatus may become unstable and uneven. In order to prevent this problem, a bubble detecting means is provided which detects whether residual bubbles exist inside the spray tank


312


in the liquid spraying apparatus. When the existence of residual bubbles has been detected, water is drained from the spray tank


312


by a residual bubble prevention and control means and the spray tank


312


is refilled with water. As a result, residual bubbles can be prevented from existing in the spray tank. For example, as shown in

FIG. 3

, each of the sealing plates


328


is formed by a transparent member such as a glass plate, a transparent plastic plate, a transparent acrylic plate or the like which is made from a transparent material. As the bubble detecting means, a monitoring camera such as a CCD camera or the like is provided (not shown) which transmits through the above-described sealing plates


328


and monitors the internal portion of the spray tank


312


by viewing from the side surface end openings of the spray tank


312


in the longitudinal direction thereof.




Immediately after the spray tank


312


has been filled with water, the internal portion of the spray tank


312


is photographed by the monitoring camera. The photographed image of the internal portion of the spray tank


312


is captured by an image processor such as a microcomputer or the like, is subjected to image processing, and detects the existence of residual bubbles. The detecting results of the existence of the residual bubbles are transmitted to the residual bubble prevention and control means which forms a part of the controller for controlling the liquid spraying apparatus.




Any structure can be employed for the bubble detecting means as far as it can detect the existence of residual bubbles. For example, it can be structured as shown in FIG.


4


. In the spray tank


312


which is shown in

FIG. 4

, a portion between the pair of topwalls


312


C extending from the external side surface of the spray tank


312


to the internal side surface thereof into which water is supplied is made to be transparent. Namely, a transparent member


312


D is made from glass, acrylic plastic or the like and is formed in a rectangular column shape. The transparent member


312


D is disposed between the pair of topwalls


312


C so as to be integrated therewith, corresponding to the groove portion


322


A made up of the nozzle holes


324


which are arranged in a line, of the nozzle plate


312


, and extending along the groove portion


322


A.




While a monitoring camera


400


being moved from one end to the other end of the transparent member


312


C in the longitudinal direction thereof, the internal portion of the spray tank


312


which has been filled with water can be photographed by scanning. The photographed image is fetched by an image processor, is subjected to image processing, and the existence of residual bubbles can be detected thoroughly.




In addition to the above-described structure, the bubble detecting means can be structured as described below.




Firstly, in the spray tank


312


which is shown in

FIG. 10

, a pressurizing actuator


352


, which pressurizes water with which a space


350


of the spray tank


312


is filled, is provided at a predetermined position facing the internal wall of the space


350


on the side nearest a water-supplying pipe


346


which is provided at one of the sealing plates


328


within the space


350


for storing water therein. Further, a pressure sensor


354


is disposed at a predetermined position which faces the internal wall of the space


350


on the side of the exhaust pipe


330


which is provided at the other of the sealing plates


328


. Means which detects the existence of the bubble F is structured such that the change of the pressure indicated by the pressure sensor


354


(if there is a bubble F, the pressure decreases) is detected when water, with which the space


350


of the spray tank


312


is filled, is pressurized by the pressurizing actuator


352


. Alternatively, means which detects the existence of the bubble F is structured such that the change of the propagation rate of the pressure is detected when water inside the space


350


is pressured by the pressurizing actuator


352


.




Secondly, in the spray tank


312


which is shown in

FIG. 11

, a pressure sensor


356


is provided at the longitudinal central portion in the space


350


which stores water therein, and faces the internal wall of the space


350


. Alternatively, means which detects the existence of a bubble F is structured such that the nozzle plate


322


of the liquid spraying apparatus is driven and water with which the space


350


of the spray tank


312


is filled is pressurized, and the change of the pressure indicated by the pressure sensor which is attached to the wall surface within the space


350


which stores water therein is detected. Alternatively, means which detects the existence of the bubble F is structured such that the change of the propagation rate of the pressure is detected when the nozzle plate


322


is driven.




Thirdly, in the spray tank


312


which is shown in

FIG. 12

, each of the sealing plates


328


which are disposed at the longitudinal end portions of the spray tank


312


is formed from a transparent member. A light emitting apparatus


358


is disposed at the side of one of the sealing plates


328


, while a light receiving apparatus


360


is disposed at the side of the other. The entire internal portion of the space


350


of the spray tank


312


is scanned with light such as laser light or the like emitted from the light emitting apparatus


358


with no gaps. The amount of light when light such as laser light or the like is incident in the light receiving apparatus


360


is detected. When light such as laser light or the like which has been emitted by the light emitting apparatus


358


is transmitted through water with which the space


350


of the spray tank


312


is filled, if there is a bubble F, a light path is thereby blocked. The amount of the light received by the light receiving apparatus


360


is changed and thereby decreases. By making use of this change, means for detecting the existence of the bubble F is structured.




Fourthly, in the spray tank


312


which is shown in

FIG. 13

, a wave transmitting device


362


which transmits ultrasonic pulses into water with which the space


350


is filled is provided at a predetermined portion which faces the internal wall of the space


350


at the side of the water supplying pipe


346


in the space


350


which stores water therein. Further, in the spray tank


312


, a wave receiving device


364


which receives ultrasonic pulses is provided at a predetermined portion which faces the internal wall of the space


350


at the side of the exhaust pipe


330


in the space


350


which stores water therein. Ultrasonic pulses are transmitted from the wave transmitting device


362


into the water with which the spray tank


312


is filled. Pulse waves received by the wave receiving device


364


are transmitted to an amplifier circuit


366


where they are amplified. Thereafter, the pulse waves which have been thus amplified are transmitted to a waveform shaping circuit


368


at which trigger pulses are generated. The wave transmitting device


362


is driven by the trigger pulses so as to generate ultrasonic pulses. By repeating this operation, the pulse intervals become a propagation time. As a result, means which detects the existence of the bubble F due to a change in the propagation time can be structured.




Fifthly, although it is not shown, means for detecting the existence of a bubble F may be structured such that a so-called “idle spray” in which the liquid spraying apparatus is driven and water with which the spray tank


312


is filled is sprayed onto portions except for the photosensitive material


16


is carried out, and the amount or state of water sprayed from the nozzle holes


324


is measured.




On the basis of the results detected by such bubble detecting means as described above, the control operation of the residual bubble prevention and control means is carried out. The residual bubble prevention and control means is structured such that a control operation is carried out by a microcomputer or the like of the image recording apparatus in accordance with the procedures illustrated in the flowchart of FIG.


5


.




Next, a description of the control operation will be given in accordance with the flowchart. In step


600


, the routine waits until a start-up switch of the liquid spraying apparatus is on. When the start-up switch of the liquid spraying apparatus is switched on, the routine proceeds to step


601


. In step


601


, the operation in which the spray tank


312


is filled with water is carried out. Water is supplied until it is judged that water supply has been completed in next step


602


. In this step


602


, when water supply has been judged to be completed, the routine proceeds to step


603


, where the bubble detecting means is operated. In step


604


, on the basis of the detecting results, if it has been judged that bubbles do not exist in the spray tank


312


, in step


605


, the liquid spraying apparatus is driven. In step


606


, water is sprayed onto the photosensitive material


16


, and water is successively sprayed from the liquid spraying apparatus until it is judged that the operation of application has been completed. In step


606


, when the application operation has been judged to be completed, the routine proceeds to step


607


, where water is drained from the spray tank


312


, and the routine proceeds to step


608


.




In step


604


, if it is judged that bubbles exist in the spray tank


312


, the routine proceeds to step


607


, where water is drained from the spray tank


312


, and the routine proceeds to step


608


.




In step


608


, it is judged whether the operation of the liquid spraying apparatus has been completed. If it is judged that the operation by the liquid spraying apparatus has been completed, the start-up switch of the liquid spraying apparatus is switched off. The control operation is finished. If it is judged that the operation has not yet been completed, the routine is controlled to return to step


601


.




As described above, in the residual bubble prevention and control means, after water has been supplied into the spray tank


312


, when bubbles are detected by the bubble detecting means, an operation in which residual bubbles are drained out as the water being drained from the spray tank


312


and by the spray tank


312


being refilled with water is repeated until the residual bubbles are drained. Accordingly, residual bubbles are drained from the spraying tank


312


, and water can be applied to the photosensitive material


16


appropriately without causing atomization failure.




As described above, the residual bubble prevention and control means is structured such that all the operations are controlled by a microcomputer. Also, the residual bubble prevention and control means can be structured such that a warning device separately prepared is operated by a signal indicating that the existence of residual bubbles has been detected by the bubble detecting means, and the user is informed of this, and water is drained from the spraying tank


312


and the spray tank


312


is refilled with water by the user, manually. The residual bubble prevention and control means is not limited to the one in which residual bubbles are removed by water being drained from the spray tank


312


or the spray tank


312


being refilled with water. For example, in order to drain residual bubbles from the spray tank, there is no problem in structuring the residual bubble prevention and control means by causing this means to automatically perform a control operation which comprises the steps of removing residual bubbles by tilting the spray tank body; removing residual bubbles by decreasing the pressure of the liquid with which the spray tank is filled; and removing residual bubbles by stirring the liquid with which the spray tank is filled.




On the other hand, as shown in

FIG. 1

, a photosensitive material magazine


106


which receives an image receiving material


108


is disposed at the upper left end portion of the housing


12


. A dye fixing material having a mordant is applied to the image forming surface of this image receiving material


108


. The image receiving material


108


is wound onto the image receiving material magazine


106


in the form of a roll such that the image forming surface of the image receiving material


108


which is pulled out from the image receiving material magazine


106


faces downward.




A pair of nip rollers


110


are disposed near an image receiving material output port in the image receiving material magazine


106


. The nip rollers


110


are able to nip the image receiving material


108


and pull out the image receiving material


108


from the image receiving material magazine


106


, and cancel the nipping.




A cutter


112


is disposed at the side of the nip rollers


110


. In the same manner as the cutter


20


for the above-described photosensitive material, the cutter


112


is, for example, a rotary type cutter formed of a stationary blade and a moving blade. The cutter


112


can cut the image receiving material


108


which is pulled out from the image receiving material magazine


106


to a length which is shorter than the photosensitive material


16


, by vertically moving the moving blade via a rotating cam or the like so as to mesh with the stationary blade.




Pairs of conveying rollers


132


,


134


,


136


and


138


and an unillustrated guide plate are disposed at the side of the cutter


112


so as to convey the image receiving material


108


which has been cut to a predetermined length, towards a heat developing and transferring section


120


.




As shown in

FIGS. 1 and 9

, the heat developing and transferring section


120


has a pair of endless belts


122


and


124


each of which is entrained around a plurality of winding rollers


140


and is formed in a loop shape whose perpendicular direction is the longitudinal direction thereof. Accordingly, when one of the winding rollers


140


is driven and rotated, the pair of endless belts


122


and


124


which are entrained around these winding rollers


140


are thereby respectively rotated.




In a loop of the endless belt


122


at the right side in

FIGS. 1 and 9

of the pair of endless belts


122


and


124


, a heating plate


126


, which is formed in a plate shape whose vertical direction is the longitudinal direction thereof, is disposed so as to face the internal peripheral portion at the left side of the endless belt


122


. An unillustrated linear heater is provided at the internal portion of the heating plate


126


. The surface of the heating plate


126


can be heated by this heater to a predetermined temperature.




Accordingly, the photosensitive material


16


is conveyed by the pair of conveying rollers


34


between the pair of endless belts


122


and


124


at the heat developing and transferring section


120


at the end of the conveying path. Further, the conveyance of the image receiving material


108


is synchronized with the conveyance of the photosensitive material


16


. In a state in which the photosensitive material


16


is conveyed prior to the image receiving material


108


by a predetermined length, the image receiving material


108


is conveyed by the pair of conveying rollers


138


at the end of the conveying path into the pair of endless belts


122


and


124


at the heat developing and transferring section


120


, and is laminated with the photosensitive material


16


.




In this case, the image receiving material


108


has widthwise and lengthwise dimensions which are smaller than those of the photosensitive material


16


. Accordingly, when the photosensitive material


16


is laminated with the image receiving material


108


, the four sides of the periphery of the photosensitive material


16


project from those of the periphery of the image receiving material


108


.




As described above, the photosensitive material


16


and the image receiving material


108


which have been laminated with each other are nipped and conveyed by the pair of endless belts


122


and


124


in a laminated state. When the laminated photosensitive material


16


and the image receiving material


108


have completely entered between the endless belts


122


and


124


, the pair of endless belts


122


and


124


stop rotating temporarily, and the nipped photosensitive material


16


and the image receiving material


108


are heated by the heating plate


126


. While the photosensitive material


16


is being nipped and conveyed, and also while it is stopped, it is heated by the heating plate


126


through the endless belt


122


. As it is heated, the photosensitive material


16


discharges a movable dye. At the same time, the dye is transferred to a dye fixing layer of the image receiving material


108


, and an image is formed on the image receiving material


108


.




At the downstream side in the direction the material is fed, of the pair of endless belts


122


and


124


, a peel-off pawl


128


is disposed. The peel-off pawl


128


engages the front edge portion of only the photosensitive material


16


out of the photosensitive material


16


and the image receiving material


108


which are nipped and conveyed between the pair of endless belts


122


and


124


, and peels the front edge portion of the photosensitive material


16


which protrudes from between the pair of the endless belts


122


and


124


, from the image receiving material


108


.




At the left side of the peel-off pawl


128


, photosensitive material discharging rollers


148


are disposed. The photosensitive material


16


is moved to the left by being guided by the peel-off pawl


128


, and can be conveyed towards a discharged photosensitive material accommodating section


150


.




The discharged photosensitive material accommodating section


150


has a drum


152


around which the photosensitive material


16


is entrained, and has a belt


154


, a portion of which is entrained around the drum


152


. The belt


154


is entrained around a plurality of rollers


156


, and is conveyed through the rotation of the rollers


156


. In accordance with this, the drum


152


can rotate.




In a state in which the belt


154


is moved due to the rotation of the rollers


156


, when the photosensitive material


16


is fed into the rollers


156


, the photosensitive material


16


can be collected around the drum


152


.




In

FIG. 1

, image receiving material discharge rollers


162


,


164


,


166


,


168


, and


170


are disposed in this order so that the image receiving material


108


can be conveyed from the bottom of the pair of endless belts


122


and


124


in a downstream direction. The image receiving material


108


which is discharged from the pair of endless belts


122


and


124


is conveyed by the image receiving material discharge rollers


162


,


164


,


166


,


168


, and


170


, and discharged into a tray


172


.




Next, the operation of the present embodiment will be explained.




In the image recording apparatus


10


having the above-described structure, after the photosensitive material magazine


14


has been set, the pair of nip rollers


18


are operated and the photosensitive material


16


is pulled out by the nip rollers


18


. When a predetermined length of the photosensitive material


16


is pulled out, the cutter


20


is operated, and the photosensitive material


16


is cut to a predetermined length, and is conveyed to the exposure section


22


in a state in which the photosensitive (exposure) surface is facing the left. The exposure device


38


is operated while the photosensitive material


16


passes through the exposure section


22


, and an image is scanned and exposed to the photosensitive material


16


which is positioned at the exposure section


22


.




When the exposure has been completed, the exposed photosensitive material


16


is fed to the water application section


50


. In the water application section


50


, as shown in

FIG. 8

, the conveyed photosensitive material


16


is fed towards the spray tank


312


by the driving of the conveying rollers


32


.




The movement and operation of the photosensitive material


16


during which the photosensitive material


16


which is conveyed along the conveying path A is deposited with water from the spray tank


312


will now be explained.




This operation on the photosensitive material


16


is carried out by the residual bubble prevention and control means using the above-described bubble detecting means. As a previous operation for spraying water from the spray tank


312


, the valve of the exhaust pipe


330


is set in a closed state by the controller. In this state, when water is atomized and sprayed, a voltage is applied to the piezoelectric elements


326


through a power source which is controlled by the controller so as to deform and extend all of the piezoelectric elements


326


simultaneously.




When the plurality of piezoelectric elements expand so as to all be extended at the same time, the pair of lever plates


320


are swung around the respective supporting portions


312


B. Accordingly, the portion of the nozzle plate


322


surrounding the nozzle holes


324


positioned between the pair of lever plates


320


is reciprocated above the conveying path A in a direction facing the photosensitive material


16


, and the nozzle plate


322


pressurizes the water inside the spray tank


312


.




In this way, together with the movement of the piezoelectric elements


326


, the water with which the spray tank


312


is filled is sprayed from the plurality of nozzle holes


324


. As a result, as shown in

FIG. 7

, the water with which the spray tank


312


is filled is sprayed and atomized from the nozzle holes


324


and can be deposited on the photosensitive material


16


during the conveyance thereof.




At this point, together with the movement of the piezoelectric elements


326


, the pair of lever plates


320


swing around their respective supporting portions


312


B, which extend in the direction the plurality of nozzle holes


324


are arranged in a line. Further, the displacement of each of the lever plates


320


is adjusted due to the structure in which each of the piezoelectric elements


326


is disposed adjacent to the supporting portion


312


B, and the end portions of the nozzle plate


322


. Accordingly, the whole portion of the nozzle plate


322


having the plurality of nozzle holes


324


displaces substantially uniformly.




For this reason, all of the nozzle holes


324


can be displaced by the substantially same fixed displacement amount along the longitudinal direction in which the nozzle holes


324


are arranged in a line. The water with which the spray tank


312


is filled can be sprayed substantially uniformly from the plurality of nozzle holes


324


. Accordingly, because the nozzle plate


322


is formed as the bottom wall surface of the spray tank


312


, it is difficult for portions of the photosensitive material


16


to remain untouched by water.




The nozzle plate


322


is formed by a thin plate member. The groove portion


322


A extending in the direction the plurality of nozzle holes


324


are arranged linearly is formed so as to be bent.




Since the nozzle plate


322


is structured by a thin plate member having the groove portion


322


A, while the rigidity of the nozzle plate


322


in a direction the plurality of nozzle holes


324


are arranged in a line is being maintained, low rigidity can be provided for the nozzle plate


322


, and the vibration amplitude needed for the nozzle holes


324


can be ensured. As a result, the operation of atomization by the application device


310


becomes stable, and the water with which the spray tank


312


is filled is reliably sprayed from the plurality of nozzle holes


324


.




Further, since the nozzle plate


322


is structured by the thin plate member, when the application device


310


is manufactured, small nozzle holes


324


having a uniform size can be formed in the nozzle plate


322


.




Since the spray tank


312


has the nozzle holes


324


from which water is sprayed, as compared to an application device in which a photosensitive material or the like has water applied thereto by being immersed into water stored in a reservoir, the application device according to the present invention is able to apply a minimum amount of water. Accordingly, the photosensitive material or the like can be dried in a short period of time.




The spray tank


312


has the plurality of nozzle holes


324


which are disposed over the entire portion in the widthwise direction of the photosensitive material


16


. Through one displacement of the plurality of nozzle holes


324


by the piezoelectric elements


326


, water can be sprayed from these nozzle holes


324


simultaneously. Accordingly, through one spraying, water can be applied to a broad range of the photosensitive material


16


. For this reason, it becomes unnecessary to scan the nozzle plate


322


on a two dimensional plane and water can be applied to a large area of the photosensitive material


16


in a short period of time, thereby minimizing the application time.




Since a plurality of nozzle holes


324


are simply formed on the nozzle plate


322


, an integration technique for nozzle holes is not needed. As a result, the application device


310


can be manufactured inexpensively




In combination with the speed at which the photosensitive material


16


is conveyed, water can be applied to the entire surface of the photosensitive material


16


by spraying water from the nozzle holes


324


for a multiple number of times at an arbitrary timing. When water is sprayed from the nozzle holes


324


of the nozzle plate


322


, the amount of water within the spray tank


312


gradually decreases. However, because a sub tank


338


can supply water into the spray tank


312


and maintain the water in the spray tank


312


at a constant level, water is supplied from the sub tank


338


to the spray tank


312


, and the water pressure in the spray tank


312


during atomization can be maintained at a constant value. Accordingly, a continuous spray of water can be maintained.




Thereafter, the photosensitive material


16


, to which water as an image forming solvent has been applied at the water application section


50


, is conveyed by the pair of conveying rollers


34


between the pair of the endless belts


122


and


124


in the heat developing and transferring section


120


.




As an image is scanned and exposed to the photosensitive material


16


, the image receiving material


108


is pulled out from the image receiving material magazine


106


and conveyed by the pair of nip rollers


110


. When a predetermined length of the image receiving material


108


is pulled out, the cutter


112


is operated and the image receiving material


108


is cut to a predetermined length.




After the cutter


112


has been operated, the cut image receiving material


108


is conveyed by the conveying rollers


132


,


134


,


136


, and


138


, while the cut image receiving material


108


is being guided by a guide plate. When the front edge portion of the image receiving material


108


is nipped by the conveying rollers


138


, the image receiving material


108


is set in a stand-by state just before the heat developing and transferring section


120


.




As described above, as the photosensitive material


16


is conveyed by the conveying rollers


34


into the endless belts


122


and


124


, the conveyance of the image receiving material


108


is started again, and the image receiving material


108


and the photosensitive material


16


are conveyed between the pair of endless belts


122


and


124


so as to be integrated with each other.




As a result, the photosensitive material


16


and the image receiving material


108


are laminated with each other, and nipped and conveyed while being heated by the heating plate


126


. Accordingly, a heat developing and transferring process is carried out, and an image is formed on the image receiving material


108


.




When the photosensitive material


16


and the image receiving material


108


are discharged from the pair of endless belts


122


and


124


, the peel-off pawl


128


engages with the front edge portion of the photosensitive material


16


which is conveyed ahead of the image receiving material


108


by a predetermined length and the leading edge of the photosensitive material


16


is peeled away from the image receiving material


108


. The photosensitive material


16


is also conveyed by the photosensitive material discharging rollers


148


and is collected in the discharged photosensitive material accommodating section


150


. At this time, since the photosensitive material


16


dries immediately, there is no need to provide a heater or the like in order to dry the photosensitive material


16


.




The image receiving material


108


which has been separated from the photosensitive material


16


is conveyed by the image receiving material discharging rollers


162


,


164


,


166


,


168


, and


170


and output to the tray


172


.




When a plurality of images are recorded on an image recording material through an image recording process, the processes described as above are sequentially carried out.




As described above, the image receiving material


108


, which has been nipped by the pair of endless belts


122


and


124


and has been subjected to the heat developing and transferring process, and on which a predetermined image has been formed (recorded) is output from the pair of endless belts


122


and


124


. Thereafter, the image receiving material


108


is nipped and conveyed by the image receiving material discharging rollers


162


,


164


,


166


,


168


, and


170


and is taken out from the image recording apparatus.




In the present embodiment, the row of nozzle holes are arranged along a line orthogonal to the direction in which the photosensitive material is conveyed, however, the row of nozzle holes may be arranged in a direction other than orthogonal, for example, they may be arranged diagonally to the direction in which the photosensitive material is conveyed.




In accordance with the above-described embodiment, the photosensitive material


16


and the image receiving material


108


are used as an image recording material. Water is applied to the photosensitive material


16


, after the exposure thereof, by the spray tank


312


of the application device


310


. The photosensitive material


16


and the image receiving material


108


are laminated onto each other and are subjected to the heat developing and transferring process. However, the structure is not limited to the same, and water may be applied by spraying to the image receiving material


108


.




An image recording material according to the present invention is not limited to the materials used in the above described embodiments. Sheet type or roll type materials can be used where suitable. The image forming solvent may be a solvent other than water. Moreover, the present invention can be employed for the application of a developer to printing paper in a developing machine, the application of dipping water in a printer, and in coating machines or the like.




As described above, in accordance with the liquid spraying apparatus of the present invention, it is possible to obtain the superior effect in which, when a reservoir having a nozzle plate is filled with a liquid, the internal portion of the reservoir is not deposited with residual bubbles and atomization failure can be prevented.



Claims
  • 1. A liquid spraying apparatus in which a nozzle plate is provided at a portion of a lower wall surface of a spray tank which stores a liquid therein, the nozzle plate has a row of nozzles made up of a plurality of nozzle holes through which the liquid is sprayed when the nozzle plate is reciprocated, comprising:at least a portion of the spray tank being formed from a transparent member; a monitoring camera which views an internal portion of said spray tank from at least a side end wall surface of said spray tank, through said transparent member; wherein said internal portion of said spray tank is photographed by said camera to determine an existence of residual bubbles in said spray tank.
  • 2. A liquid spraying apparatus comprising:a nozzle plate provided at a portion of a lower wall surface of a spray tank which stores a liquid therein, the nozzle plate having a row of nozzles made up of a plurality of nozzle holes through which the liquid is sprayed when the nozzle plate is reciprocated; bubble detecting means which, when said spray tank is filled with the liquid, detect whether or not residual bubbles exist inside said spray tank; residual bubble prevention and control means which, when receiving a signal indicating that an existence of residual bubbles has been detected by said bubble detecting means, carries out a control operation in which the liquid with which said spray tank is filled is drained, and said spray tank is refilled with a liquid.
  • 3. A liquid spraying apparatus according to claim 2, wherein said residual bubble prevention and control means is a control operation which removes the residual bubbles by decreasing the pressure of the liquid with which said spray tank is filled.
  • 4. A liquid spraying apparatus in which a nozzle plate is provided at a portion of a lower wall surface of a spray tank which stores a liquid therein, the nozzle plate has a row of nozzles made up of a plurality of nozzle holes through which the liquid is sprayed when the nozzle plate is reciprocated, comprising:a bubble detecting means which, when said spray tank is filled with the liquid, detects whether or not residual bubbles exist inside said spray tank; and residual bubble prevention and control means which, when receiving a signal indicating that an existence of residual bubbles has been detected by said bubble detecting means, drains said residual bubbles; wherein said bubble detecting means detects the existence of residual bubbles by monitoring the internal portions of said spray tank by using a monitoring camera, at least one portion of said spray tank being formed from a transparent member, and said monitoring camera viewing an internal portion of said spray tank from at least a side end wall surface of said spray tank, through said transparent member.
  • 5. A liquid spraying apparatus in which a nozzle plate is provided at a portion of a lower wall surface of a spray tank which stores a liquid therein, the nozzle plate has a row of nozzles made up of a plurality of nozzle holes through which the liquid is sprayed, is reciprocated, comprising:a bubble detecting means which, when said spray tank is filled with the liquid, detects whether or not residual bubbles exist inside spray tank; and residual bubble prevention and control means which, when receiving a signal indicating that an existence of residual bubbles has been detected by said bubble detecting means, carries out a control operation in which the liquid with said spray tank is filled is drained, and said spray tank is refilled with a liquid; wherein said bubble detecting means detects the existence of residual bubbles by monitoring the internal portions of said spray tank by using a monitoring camera, at least one portion of said spray tank being formed from a transparent member, and said monitoring camera viewing an internal portions of said spray tank from at least a side end wall surface of said spray tank, through said transparent member.
Priority Claims (1)
Number Date Country Kind
10-068210 Mar 1998 JP
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4324117 Schwob et al. Apr 1982 A
4367736 Gupton Jan 1983 A
4368478 Koto Jan 1983 A
4498088 Kanayama Feb 1985 A
4533082 Maehara et al. Aug 1985 A
4545650 Kirkman et al. Oct 1985 A
5163617 Clifford et al. Nov 1992 A
5354999 Neff Oct 1994 A
5487378 Robertson et al. Jan 1996 A
5505777 Ciardella et al. Apr 1996 A
5950691 Abe et al. Sep 1999 A
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5991019 Saner et al. Nov 1999 A
Foreign Referenced Citations (1)
Number Date Country
9-179273 Jul 1997 JP