Information
-
Patent Grant
-
6622934
-
Patent Number
6,622,934
-
Date Filed
Tuesday, February 23, 199925 years ago
-
Date Issued
Tuesday, September 23, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 239 1022
- 239 63
- 239 71
- 239 74
- 239 99
- 239 101
-
International Classifications
-
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 |
|
US Referenced Citations (18)
Foreign Referenced Citations (1)
Number |
Date |
Country |
9-179273 |
Jul 1997 |
JP |