JPH11128839A - Solvent applicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a solvent applicator of a low cost. SOLUTION: When water is not ejected, a command voltage of a high level is impressed on the respective bases of NPN type transistors(TRs) 412, 424 and the respective TRs are turned on. When the NPN type TR 412 is turned on, an FET 420 is turned off and, therefore, the impression of the voltage on a piezoelectric element 326 is not executed. At this time, the charges accumulated in the piezoelectric element 326 are discharged in an R1 direction. When, on the other hand, water is ejected, the command voltage of a low level is impressed on the respective bases of the NPN type TRs 412, 424 and the respective TRs are turned off. When the NPN type TR 414 is tuned off, the FET 420 is turned on and, therefore, a current flows from a reference power source 416 in an R2 direction and the prescribed voltage is applied on the piezoelectric element 326. As a result, the displacement of the piezoelectric element 326 is made possible and the water may be gushed by this displacement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solvent coating apparatus, and more particularly, to a solvent coating apparatus for ejecting a solvent filled in a pressurizing chamber of a solvent coating apparatus according to displacement of a piezoelectric element.

[0002]

2. Description of the Related Art There is known an image forming apparatus which performs an image recording process using two types of image recording materials, for example, a photosensitive material and an image receiving material.

In this type of image forming apparatus, an image forming solvent application section having a tank for storing an image forming solvent to be applied to a photosensitive material is arranged. Further, a heating drum and a heating drum are provided. A heat development transfer section comprising an endless pressure contact belt which is pressed against the outer periphery and rotates together with the heating drum is arranged.

The photosensitive material, to which an image has been exposed while being nipped and conveyed in the image forming apparatus, is immersed in a tank in which water as an image forming solvent is stored in an image forming solvent coating section, and is coated with water. Later, it is sent to the thermal development transfer section. On the other hand, the image receiving material is sent to the thermal development transfer unit in the same manner as the photosensitive material.

In the thermal development transfer section, the photosensitive material after water application is superimposed on the image receiving material, and in this state, the photosensitive material is closely wound around the outer periphery of the heating drum. Further, the photosensitive material is thermally developed while the two materials are nipped and conveyed between the heating drum and the endless pressure contact belt, and the image is transferred to the image receiving material, whereby a predetermined image is formed (recorded) on the image receiving material.

However, when a photosensitive material is immersed and applied in a tank containing water as a solvent for image formation, water once in contact with the photosensitive material is always kept in the tank, and as a result, only a small amount of water is generated from the photosensitive material. Bacteria are propagated in the tank using the organic substance eluted in the water as a nutrient source, and water is contaminated, which may cause deterioration of the image forming apparatus itself and deterioration of image quality.

Therefore, a nozzle plate provided with a plurality of nozzle holes for jetting the solvent for image formation is provided as a part of the wall of the pressurizing chamber so that the water supply side of the tank or the like is not in contact with the photosensitive material. It has been considered that a small water droplet is ejected to a photosensitive material by vibrating to apply the droplet. A piezoelectric element is most suitable as an actuator for vibrating the nozzle plate. By applying a voltage to the piezoelectric element, the nozzle plate is reciprocated (amplitude), and the pressure chamber is pressurized and depressurized, so that a predetermined amount of water droplet can be ejected.

Conventionally, in a solvent coating apparatus used for such purposes as jetting a solvent for image formation, as shown in FIG. 14, a command voltage, which is a command signal for instructing the timing of jetting the solvent, is used. In order to obtain a voltage (several tens of volts) capable of displacing the piezoelectric element 326 by a required amount, a commercially available general-purpose amplifier 430 that amplifies the command voltage by, for example, ten times and applies the amplified voltage to the piezoelectric element 326 has been used.

[0009]

However, when a commercially available general-purpose amplifier is used as a driver for driving the piezoelectric element of the solvent coating apparatus as described above, there is a problem that the cost of the solvent coating apparatus increases. .

The present invention has been made to solve the above problems, and has as its object to provide a low-cost solvent coating apparatus.

[0011]

According to a first aspect of the present invention, there is provided a solvent coating apparatus comprising: a pressurizing chamber filled with a solvent and having a nozzle hole; A solvent application device for ejecting the solvent filled in the pressurized chamber from the nozzle hole in accordance with the displacement of the piezoelectric element, wherein a command for instructing the timing of ejection of the solvent is provided. A signal output unit that outputs a signal; and a switching element that turns on and off the application of a voltage to the piezoelectric element based on the command signal.

According to the first aspect of the present invention, the command signal for instructing the timing of the ejection of the solvent is output by the signal output means, and the voltage of the voltage to the piezoelectric element is changed by the switching element based on the command signal. The application is turned on and off. Therefore, when a voltage is applied to the piezoelectric element by the switching element, the solvent is ejected by displacement of the piezoelectric element. Note that a transistor, a relay switch, or the like can be used as the switching element.

As described above, according to the solvent coating apparatus of the first aspect, the driver for driving the piezoelectric element can be constituted by the low-cost switching element, so that it can be compared with the case where a commercially available general-purpose amplifier is used. Thus, a low-cost solvent application device can be obtained.

Further, the solvent application device according to the second aspect of the present invention includes a pressurizing chamber filled with a solvent and having a nozzle hole, and a piezoelectric element which is displaced by applying a voltage.
A solvent application device that ejects a solvent filled in the pressurized chamber from the nozzle hole according to the displacement of the piezoelectric element,
A signal output means for outputting a command signal for instructing the timing of the ejection of the solvent, and a discharge circuit for forming a discharge circuit for discharging electric charges accumulated in the piezoelectric element by being electrically connected to the piezoelectric element. A resistance, based on the command signal, applies a voltage to the piezoelectric element when ejecting the solvent, does not conduct the piezoelectric element and the discharge resistor, and does not eject the solvent when ejecting the solvent. A switching element that does not apply a voltage to the piezoelectric element and conducts the piezoelectric element and the discharge resistor.

According to the second aspect of the present invention, the command signal for instructing the timing of the ejection of the solvent is output by the signal output means, and the solvent is ejected by the switching element based on the command signal. When a voltage is applied to the piezoelectric element, the piezoelectric element and the discharge resistor are not conducted, and when the solvent is not ejected, no voltage is applied to the piezoelectric element and the piezoelectric element and the discharge resistor are conducted and the piezoelectric element is conducted. A discharge circuit for discharging the electric charge stored in the element is formed.

As described above, according to the solvent coating apparatus of the second aspect, a driver for driving the piezoelectric element can be constituted by the inexpensive switching element and discharge resistor, so that a commercially available general-purpose amplifier is used. Compared to when
A low-cost solvent application device can be obtained, and the discharge time of the electric charge accumulated in the piezoelectric element when the solvent is not ejected can be made variable by changing the resistance value of the discharge resistor. it can.

The voltage applied to the piezoelectric element may be obtained from a reference power supply provided in advance in the solvent coating apparatus, or may be compared to the voltage applied to the piezoelectric element. Then, a capacitor having a large capacitance may be provided, and a necessary amount of electric charge for displacing the piezoelectric element may be stored in the capacitor in advance, and the capacitor may be obtained from the capacitor.

[0018]

FIG. 1 is a schematic overall configuration diagram of an image recording apparatus 10 according to an embodiment of the present invention.

In the machine base 12 of the image recording apparatus 10, a photosensitive material magazine 14 for storing a photosensitive material 16 is disposed, and the photosensitive material 1 extracted from the photosensitive material magazine 14 is disposed.
The photosensitive material 16 is wound around a photosensitive material magazine 14 in a roll shape such that the photosensitive (exposure) surface 6 faces left.

A nip roller 18 and a cutter 20 are arranged in the vicinity of the photosensitive material outlet of the photosensitive material magazine 14, so that the photosensitive material 16 can be cut out after the photosensitive material 16 is drawn out from the photosensitive material magazine 14 by a predetermined length. The cutter 20
For example, it is a rotary type cutter including a fixed blade and a movable blade. The movable blade can be moved left and right by a rotating cam or the like to cut the photosensitive material 16 by meshing with the fixed blade.

Above the cutter 20, a plurality of transport rollers 24, 26, 28, 30, 32, and 34 are sequentially arranged, and a guide plate (not shown) is provided between the transport rollers. The photosensitive material 16 cut to a predetermined length is first conveyed to an exposure section 22 provided between conveying rollers 24 and 26.

An exposure device 38 is provided on the left side of the exposure section 22. The exposure device 38 is provided with three types of LDs, a lens unit, a polygon mirror, and a mirror unit (all are not shown). Are exposed.

Above the exposure section 22, there are provided a U-turn section 40 for transporting the photosensitive material 16 in a U-shaped curve and a water application section 50 for applying an image forming solvent. In the present embodiment, water is used as the image forming solvent.

The photosensitive material 16 ascended from the photosensitive material magazine 14 and exposed at the exposure unit 22 is nipped and conveyed by conveyance rollers 28 and 30, respectively, and is applied with water while passing through a conveyance path on the upper side of the U-turn unit 40. It is sent to the unit 50.

On the other hand, as shown in FIG. 2, an injection tank 312 which constitutes a part of a coating device 310 as a solvent coating device is disposed at a position of the water coating section 50 facing the conveyance path A of the photosensitive material 16. ing.

As shown in FIG. 2, a water bottle 332 for storing water to be supplied to the injection tank 312 is disposed at the lower left of the injection tank 312, which is a pressurized chamber filled with water. A filter 334 for filtering water is disposed above the water bottle 332. Then, the water supply pipe 34 in which the pump 336 is disposed on the way.
2 connects the water bottle 332 and the filter 334.

Further, on the right side of the injection tank 312, a sub tank 338 for storing the water sent from the water bottle 332 is provided.
Is disposed, and the water supply pipe 34 is
4 extends to the sub-tank 338.

Therefore, when the pump 336 operates, water is sent from the water bottle 332 to the filter 334 side, and water filtered through the filter 334 is sent to the sub-tank 338, and the water is temporarily stored in the sub-tank 338. Will be able to

The sub tank 338 and the injection tank 31
A water supply pipe 346 connecting the water bottle 332 and the water bottle 332 via a filter 334, a sub tank 338, a water supply pipe 346, and the like.
The water sent at 36 will fill this injection tank 312.

A tray 340 connected to a water bottle 332 by a circulation pipe 348 is disposed below the injection tank 312. The tray 340 collects water overflowing from the injection tank 312 and passes through the circulation pipe 348. To return to the water bottle 332. The circulation pipe 348 is connected to the sub-tank 338 in a state of protruding and extending into the sub-tank 338, and excessive water accumulated in the sub-tank 338 is supplied to the water bottle 332.
I am going to put it back.

Further, as shown in FIGS. 4 and 6, a rectangular thin plate which can be elastically deformed is provided on a part of the wall surface of the injection tank 312 which faces the transport path A of the photosensitive material 16. A bent nozzle plate 322 is provided.

As shown in FIGS. 3 to 5, the nozzle plate 322 has a plurality of nozzle holes 324 (for example, several tens μm in diameter) for injecting water filled in the injection tank 312. The transport direction A of the photosensitive material 16 at regular intervals
The photosensitive material 16 is arranged over the entire width direction of the photosensitive material 16 while being linearly arranged along a direction intersecting with the photosensitive material 16. Because of this,
The water in the injection tank 312 can be discharged to the photosensitive material 16 side from each of the nozzle holes 324.

On the other hand, as shown in FIGS. 2 and 3, an exhaust pipe 330 extends from the upper part of the injection tank 312,
The exhaust pipe 330 allows communication between the inside and the outside of the injection tank 312. A valve (not shown) for opening and closing the exhaust pipe 330 is provided in the middle of the exhaust pipe 330, and the opening and closing movement of the valve allows the inside of the injection tank 312 to communicate with and close to outside air. I have.

As shown in FIG. 6, both ends of the nozzle plate 322 in the width direction are respectively connected to a pair of lever plates 320 by bonding with an adhesive or the like.
2 and a pair of lever plates 320 are connected. The pair of lever plates 320 are connected to the pair of side walls 3 of the injection tank 312.
Narrow support portions 312 respectively formed at the lower portion of 12A
B are fixed to the pair of side walls 312A via B, respectively.

On the other hand, a part of a pair of top walls 312C that abut against each other to form the injection tank 312
2 protruding to the outside of the protruding top wall 312
C, a plurality of piezoelectric elements 3 serving as actuators
26 (three on each side in the present embodiment) are bonded and arranged. On the lower surface of the piezoelectric element 326,
The outer end side of the lever plate 320 is bonded, and the piezoelectric element 326 and the lever plate 320 are connected.

Accordingly, the piezoelectric element 326 and the lever plate 3
20 and the support portion 312B constitute a lever mechanism, and when the outer end side of the lever plate 320 is moved by the piezoelectric element 326, the lever plate 320 is moved in the opposite direction to this movement.
The inner end side of the will move. The piezoelectric element 326
Is made of laminated piezoelectric ceramics, for example, and the displacement of the piezoelectric element 326 in the axial direction is increased. The timing of voltage application is controlled by a controller 400 described later. And, the above-mentioned exhaust pipe 33
The valve for opening and closing 0 is also connected to the controller 400, and the controller 400 also controls the opening and closing operation of the valve.

On the other hand, the lever plate 320 and the side wall 312
A, the support portion 312B and the top wall 312C respectively form a part of an integrally formed frame 314,
As shown in FIG. 6, a pair of the frames 314 is overlapped and screwed with a bolt (not shown),
The outer frame of the injection tank 312 is formed in a state where the pair of lever plates 320, the pair of side walls 312A, the pair of top walls 312C, and the pair of support portions 312B are arranged to face each other.

Further, a thin walled portion is defined by the left and right ends of the nozzle plate 322, which are the ends of the nozzle plate 322 positioned in the longitudinal direction of the nozzle hole 324, and the ends of the pair of frames 314. The stop plate 328 is arranged in a state of being bonded to the pair of frames 314.

Further, gaps between the left and right ends of the nozzle plate 322 and the ends of the pair of frames 314 and the sealing plate 328 are filled inside the sealing plate 328, and water is supplied from between them. In order to prevent leakage, an elastic adhesive, for example, a silicone rubber-based adhesive is filled. Therefore, the gap of the injection tank 312 is sealed by the elastic adhesive without obstructing the movement of the left and right ends of the nozzle plate 322. Note that the injection tank 3 is not used without using the thin sealing plate 328.
The left and right ends of 12 may be sealed with only an elastic adhesive.

As described above, when power is supplied to the piezoelectric element 326 from the power supply, as shown in FIG. 7, the piezoelectric element 326 is extended and the lever plate 320 is rotated around the support portion 312B, and the piezoelectric element 326 is rotated. The nozzle plate 322 is moved so that the element 326 raises the center of the nozzle plate 322 along the arrow B direction.
Is displaced while being deformed. And this nozzle plate 32
With the deformation of 2, the pressure of the water in the injection tank 312 increases, and a small amount of water L is jetted from the nozzle hole 324 collectively and linearly.

On the other hand, as shown in FIG. 1, a receiving magazine 10 for storing an image receiving material 108 is provided at the upper left end in the machine base 12.
6 are arranged. A dye fixing material having a mordant is applied to the image forming surface of the image receiving material 108, and the image receiving material 108 is pulled out from the material receiving magazine 106 so that the image forming surface of the image receiving material 108 faces downward. It is wound in a roll shape around 106.

A nip roller 110 is disposed in the vicinity of the image receiving material take-out opening of the material receiving magazine 106 so that the image receiving material 108 can be pulled out from the material receiving magazine 106 and the nip can be released.

The cutter 11 is provided beside the nip roller 110.
2 are arranged. The cutter 112 is, for example, a rotary type cutter including a fixed blade and a movable blade, similar to the above-described photosensitive material cutter 20, and the movable blade is moved up and down by a rotating cam or the like to engage with the fixed blade. Thereby, the image receiving material 108 drawn out from the receiving material magazine 106 is cut into a shorter length than the photosensitive material 16.

The transport roller 13 is provided beside the cutter 112.
2, 134, 136, 138 and a guide plate (not shown) are arranged, and the image receiving material 108 cut to a predetermined length is provided.
Can be conveyed to the thermal development transfer unit 120 side.

As shown in FIGS. 1 and 10, the heat development transfer section 120 is wound around a plurality of winding rollers 140, and each has a pair of endless belts 122 formed in a loop with the longitudinal direction being the longitudinal direction. , 124. Therefore, when one of these winding rollers 140 is driven and rotated, the pair of endless belts 122 and 124 wound around these winding rollers 140 are respectively rotated.

In the figure, the heating plate 12 formed in a flat plate shape with the vertical direction as the longitudinal direction is provided in the loop of the endless belt 122 on the right side of the pair of endless belts 122 and 124.
6 is disposed facing the inner peripheral portion on the left side of the endless belt 122. A linear heater (not shown) is disposed inside the heating plate 126, and the heater can heat the surface of the heating plate 126 to a predetermined temperature.

Accordingly, the photosensitive material 16 is fed between the pair of endless belts 122 and 124 of the thermal development transfer section 120 by the last transport roller 34 in the transport path. Further, the image receiving material 108 is transported in synchronization with the transport of the photosensitive material 16,
In a state where the photosensitive material 16 is advanced by a predetermined length, the photosensitive material 16 is fed between the pair of endless belts 122 and 124 of the thermal development transfer unit 120 by the last transport roller 138 in the transport path, and is superposed on the photosensitive material 16.

In this case, the image receiving material 108 is the photosensitive material 16
Both the width dimension and the longitudinal dimension are smaller than that of the photosensitive material 16, so that the periphery of the photosensitive material 16 is overlapped with all four sides protruding from the periphery of the image receiving material 108.

As described above, the pair of endless belts 122, 12
Photosensitive material 16 and image receiving material 1
08 is nipped and conveyed by a pair of endless belts 122 and 124 while being superposed.
Further, the superposed photosensitive material 16 and image receiving material 108
However, when completely stopped between the pair of endless belts 122 and 124, the pair of endless belts 122 and 124 stop rotating once, and the sandwiched photosensitive material 16 and image receiving material 108 are heated by the heating plate 126. The photosensitive material 16 is heated by the heating plate 126 via the endless belt 122 at the time of the nipping conveyance and at the time of stopping, and the movable dye is released with the heating, and at the same time, the dye is transferred to the image receiving material 108.
Is transferred to the dye fixing layer, and an image is obtained on the image receiving material 108.

Further, a pair of endless belts 122, 124
On the downstream side in the material supply direction, a peeling claw 128 is arranged.
Of the photosensitive material 16 and the image receiving material 108 nipped and transported between the endless belts 2 and 124, only the leading end of the photosensitive material 16 is engaged, and the leading end of the photosensitive material 16 protruding from between the pair of endless belts 122 and 124. It can be peeled off from the image receiving material 108.

At the left of the peeling claw 128, the photosensitive material discharge roller 1
The photosensitive material 16, which is moved leftward while being guided by the peeling claw 128, can be further transported to the waste photosensitive material container 150 side.

The waste photosensitive material storage section 150 has a drum 152 around which the photosensitive material 16 is wound, and a belt 154 partially wound around the drum 152. Further, the belt 154 includes a plurality of rollers 15.
The belt 154 is rotated by the rotation of the rollers 156, and the drum 1
52 rotates.

Therefore, when the photosensitive material 16 is fed in a state where the belt 154 is rotated by the rotation of the roller 156, the photosensitive material 16 can be accumulated around the drum 152.

On the other hand, in FIG. 1, a pair of endless belts 122,
Receiving rollers 162, 164, 166, and so on, so that the image receiving material 108 can be conveyed from below to the left from below.
168 and 170 are arranged in this order, and the image receiving material 108 discharged from the pair of endless belts 122 and 124 receives these image receiving rollers 162 164 166 168 and 168.
The paper is conveyed by 170 and discharged to the tray 172.

FIG. 11 shows a controller 400 for applying a voltage to the piezoelectric element 326 in the water application section 50 and controlling a valve for opening and closing the exhaust pipe 330.

The power supply line 402 has a stabilized power supply 404
A microcomputer 406 serving as a signal output unit of the present invention is connected via the CPU, and a control program is stored in advance. A driver 408 for opening and closing the valve of the exhaust pipe 330 is connected to the microcomputer 406, and a driver 410 for applying a voltage to the piezoelectric element 326 is connected to the microcomputer 406.

FIG. 12 shows an example of a circuit constituting the driver 410. Microcomputer 406
The signal line that inputs the command voltage as the command signal from
The collector of the NPN transistor 412 is connected to a reference power supply 416 for outputting a predetermined voltage via a resistor 414. The emitter of the NPN transistor 412 is grounded. The reference power supply 416
The predetermined voltage is set in advance as a magnitude that can eventually displace the piezoelectric element 326 by a required amount.

The collector of the NPN transistor 412 is further connected to the gate of a field effect transistor (hereinafter referred to as FET) 420 via a resistor 418, and the drain of the FET 420 is connected to the reference power supply 416. Have been. The source of the FET 420 is connected to one terminal of the piezoelectric element 326 via the resistor 422. Note that the other terminal of the piezoelectric element 326 is grounded. Therefore, when the FET 420 is turned on, a predetermined voltage is applied to the piezoelectric element 326 by the reference power supply 416, and the piezoelectric element 326 is displaced according to the magnitude of the applied voltage.

On the other hand, a signal line for inputting a command voltage from the microcomputer 406 is connected to the NPN transistor 4
The collector of the NPN transistor 424 is connected to one terminal of the piezoelectric element 326 via the resistor 426 serving as a discharge resistor of the present invention. The emitter of the NPN transistor 424 is grounded. Therefore, when the FET 420 is turned off and the NPN transistor 424 is turned on, a discharge circuit is formed to discharge the electric charge accumulated in the piezoelectric element 326 by the piezoelectric element 326, the resistor 426, and the NPN transistor 424. .

The NPN transistor 412,
Each of the FET 420 and the NPN transistor 424 corresponds to a switching element of the present invention.

The operation of the present embodiment will be described below. In the image recording apparatus 10 having the above configuration, after the photosensitive material magazine 14 is set, the nip roller 18 is operated, and the photosensitive material 16 is pulled out by the nip roller 18. When the photosensitive material 16 is pulled out by a predetermined length, the cutter 20 operates to cut the photosensitive material 16 into a predetermined length,
The sheet is conveyed to the exposure unit 22 with its photosensitive (exposure) surface facing left. Then, the exposure device 38 is operated simultaneously with the passage of the photosensitive material 16 through the exposure unit 22, and the image is scanned and exposed on the photosensitive material 16 located at the exposure unit 22.

When the exposure is completed, the exposed photosensitive material 16 is exposed.
Is sent to the water application unit 50. In the water application section 50, the conveyed photosensitive material 16 is sent to the ejection tank 312 side by driving the conveying roller 32 as shown in FIG.
It is transported along the transport path A.

In the water application section 50, first, the controller 4
00, the valve of the exhaust pipe 330 is closed. When water is sprayed from the nozzle plate 322 while atomizing in this state, the piezoelectric element 32 is controlled by the controller 400.
A voltage is applied to 6 to deform all the piezoelectric elements 326 so as to extend simultaneously.

When the piezoelectric element 326 is deformed in this way,
The displacement is transmitted to the nozzle plate 322 via the rotation of the pair of lever plates 320 around the support portion 312B, and the nozzle plate 32
2 is displaced to pressurize the water in the injection tank 312. As a result, as shown in FIG. 7, the water filled in the ejection tank 312 can be ejected from the nozzle hole 324 while being atomized, and can be attached to the photosensitive material 16 being conveyed.

At this time, as shown in FIG.
The voltage applied to the piezoelectric element 326 that displaces the nozzle plate 322 rises so as to change in a time shorter than the period T of the natural frequency of the nozzle plate 322, and fluctuates, for example, by 50 V to the plus side, so that the nozzle hole of the nozzle plate 322 is changed. 324 is displaced as shown in FIG.
Water is injected from each of the four. Further, after the voltage applied to the piezoelectric element 326 is held for a certain period of time, the nozzle plate 322 is dropped so as to change over a period longer than the period T of the natural frequency of the nozzle plate 322. Return to the original position before water injection. The rise time of the voltage applied to the piezoelectric element 326 at this time is determined by the resistance 422.
The fall time can be set by adjusting the resistance value of the resistor 426 (see FIG. 12).

As described above, since the nozzle plate 322 is displaced in a time shorter than the period T of the natural frequency of the nozzle plate 322,
The amplitude required for the nozzle plate 322 and the pressure applied to the water in the injection tank 312 required for atomization are secured, and the coating device 3
10 atomization operations are stabilized. For this reason, water is reliably jetted from the plurality of nozzle holes 324.

Further, since the nozzle plate 322 is slowly returned to the original position before the water injection for a time longer than the period T of the natural frequency of the nozzle plate 322, the influence of the vibration of the nozzle plate 322 itself becomes less. For this reason, as water is ejected from the nozzle holes 324, the nozzle plate 32
Bubbles do not enter into the injection tank 312 inside the nozzle 2 due to negative pressure, and there is no possibility that the nozzle holes 324 are blocked by the bubbles and water is not ejected from the nozzle holes 324.

As a result, a portion where water does not adhere to the photosensitive material 16 does not occur, and water can be uniformly applied to the photosensitive material 16.

Further, preferably, as shown in FIG. 8, the voltage applied to the piezoelectric element 326 is set to a value equal to or less than one half of the cycle T of the natural frequency of the nozzle plate 322, for example, about one tenth of the cycle T. By changing the value to the plus side so as to change, the atomization operation is further stabilized, and a portion where water does not adhere to the photosensitive material 16 is more unlikely to occur.

On the other hand, preferably, as shown in FIG. 8, the voltage applied to the piezoelectric element 326 is changed to the minus side so as to change in a time period of three times or more the period T of the natural frequency of the nozzle plate 322. By returning the nozzle plate 322 to the original position before the injection of water, there is no longer a possibility that bubbles may enter the injection tank 312 from the nozzle holes 324 more. That is, when three or more cycles in which the vibration of the nozzle plate 322 is sufficiently attenuated, by returning the nozzle plate 322 to the original state, there is a further possibility that the nozzle holes 324 are blocked by bubbles and no water comes out from the nozzle holes 324. Disappears.

Here, the value of the current flowing through the piezoelectric element 326 is
For example, 2A, 1A, 0.5A, etc. can be considered. In the case of 2A, a current flows for 38 μs, in the case of 1A, a current flows for 76 μs, and in the case of 0.5A, 15
A current is passed for only 2 μsec to secure a predetermined voltage.

Further, as shown in FIG. 9, instead of the trapezoidal shape shown in FIG. 8, the rising side of the voltage is simply set to not more than half of the period T of the natural frequency of the nozzle plate 322, and The lower side may be set to three times or more of the period T, and a saw-tooth waveform may be used in which there is no time to keep the voltage constant.

On the other hand, in the present embodiment, the nozzle holes 324
Since water is sprayed from the apparatus, it is possible to apply with a small amount of water and dry the water in a short time as compared with an application apparatus in which a photosensitive material or the like is immersed and applied in a tank in which water is stored. Become like

Further, the injection tank 312 has a plurality of nozzle holes 324 arranged over the entire width of the photosensitive material 16 in the width direction.
Since water is simultaneously ejected from these nozzle holes 324 by one displacement by the piezoelectric element 326, water can be applied over a wide area over the entire width of the photosensitive material 16 by one ejection. For this reason, the nozzle plate 32
It is not necessary to scan 2 on a two-dimensional plane, and it is possible to apply a large area in a short time, thereby shortening the application time.

Further, lever plates 320 are connected at both ends of the nozzle plate 322 in a direction orthogonal to the longitudinal direction of the nozzle holes 324, and the nozzle plate 322 and the piezoelectric element 326 are connected via the lever plates 320. Therefore, the nozzle holes 324 can be stably displaced collectively along the longitudinal direction of the plurality of nozzle holes 324 arranged linearly with the same displacement amount, and uniform application of water to the photosensitive material 16 can be achieved. Becomes possible.

The water is applied over the entire surface of the photosensitive material 16 by spraying the water from the nozzle holes 324 many times at an arbitrary timing in combination with the transport speed of the photosensitive material 16.

On the other hand, since the particle size is determined by the nozzle holes 324 and the gas is not mixed with the liquid, there is no variation in the particle size, and the nozzle holes 324 are arranged linearly at regular intervals. Therefore, the dispersion of the landing position is eliminated. Therefore, these variations do not hinder the uniformity of the liquid on the surface of the photosensitive material 16 which is the coated surface.

Further, since the nozzle plate 322 having the nozzle holes 324 does not come into contact with the photosensitive material 16, clogging and contamination are eliminated, and the durability of the coating apparatus 310 is improved.

On the other hand, since it is only necessary to form a plurality of nozzle holes 324 in the nozzle plate 322, no integration technique is required, and the coating apparatus 310 can be manufactured at low cost.

Then, the nozzle hole 324 of the nozzle plate 322 is
When water is injected from the sub-tank 338, the water in the injection tank 312 sequentially decreases, but since the sub-tank 338 has a function of supplying water to keep the water level in the injection tank 312 constant, Water is supplied, and the water pressure in the injection tank 312 during atomization can be maintained at a constant value, and continuous water injection is ensured.

Next, the operation of the driver 410 shown in FIG. 12 will be described. In this embodiment, the command voltage applied from the microcomputer 406 to the driver 410 is a high-level voltage when water is not ejected (when off) as shown in FIG. 12 and water is ejected. (When turned on) is a low-level voltage.

Therefore, when water is not ejected, NPN
Transistor 412 and NPN transistor 424
A high level command voltage is applied to both bases,
Both transistors are turned on.

When the NPN transistor 412 is turned on, the FET 420 is turned off, so that no voltage is applied to the piezoelectric element 326 by the reference power supply 416. At this time, since the NPN transistor 424 is turned on, when electric charge is accumulated in the piezoelectric element 326,
The charges are discharged in the direction of arrow R1 in FIG.

On the other hand, when water is ejected, a low-level command voltage is applied to the bases of both the NPN transistor 412 and the NPN transistor 424, and both transistors are turned off.

When the NPN transistor 414 is turned off, the FET 420 is turned on by the reference power supply 416. Therefore, a current flows from the reference power supply 416 in the direction of arrow R2 in FIG. 12, and a predetermined voltage is applied to the piezoelectric element 326. The piezoelectric element 326 can be displaced. At this time, since the NPN transistor 424 is turned off, the electric charge accumulated in the piezoelectric element 426 is not discharged.

Thereafter, the photosensitive material 16 to which the water as an image forming solvent has been applied in the water application section 50 is fed by the conveying roller 34 between the pair of endless belts 122 and 124 of the heat development transfer section 120.

On the other hand, as the photosensitive material 16 is scanned and exposed, the image receiving material 108 is also pulled out from the material receiving magazine 106 by the nip roller 110 and transported. When the image receiving material 108 is pulled out by a predetermined length, the cutter 112 operates to cut the image receiving material 108 into a predetermined length.

After the operation of the cutter 112, the cut image receiving material 108 is transported by the transport rollers 132, 134, 136 and 138 while being guided by the guide plate. When the leading end of the image receiving material 108 is nipped by the transport roller 138, the image receiving material 108 is transferred to the heat development transfer unit 120.
Is in a standby state just before.

As the photosensitive material 16 is fed between the pair of endless belts 122 and 124 by the conveying rollers 34 as described above, the conveyance of the image receiving material 108 is resumed, and the pair of endless belts 122 and 124 are resumed. The image receiving material 108 is fed integrally with the photosensitive material 16 between them.

As a result, the photosensitive material 16 and the image receiving material 108
Are stacked, the photosensitive material 16 and the image receiving material 108 are nipped and conveyed while being heated by the heating plate 126, and are subjected to thermal development transfer to form an image on the image receiving material 108.

Further, a pair of endless belts 122, 124
When these are discharged from the image receiving material 108, the peeling claw 128 engages with the leading end of the photosensitive material 16 which is transported a predetermined length ahead of the image receiving material 108, and the leading end of the photosensitive material 16 is
Peel from 8. The photosensitive material 16 is further conveyed by a photosensitive material discharge roller 148 and is disposed in the waste photosensitive material storage unit 1.
50. At this time, since the photosensitive material 16 dries immediately, it is not necessary to further provide a heater for drying the photosensitive material 16.

On the other hand, the image receiving material 108 separated from the photosensitive material 16 is applied to receiving material discharge rollers 162, 164, 166, and 1
The sheet is conveyed by 68 and 170 and discharged to the tray 172.

When a plurality of image recording processes are performed, the above-described steps are sequentially and sequentially performed.

As described above, the pair of endless belts 122, 1
The image receiving material 108 on which a predetermined image is formed (recorded) by the thermal development transfer process sandwiched between the pair of endless belts 1
After being discharged from the transfer rollers 22 and 124, the transfer material is nipped and conveyed by a plurality of receiving material discharge rollers 162, 164, 166, 168 and 170 and is taken out of the apparatus.

As described in detail above, the driver 410 of the coating apparatus 310 according to the present embodiment is composed of only low-cost components such as a switching element such as an NPN transistor and a resistor 426 as a discharge resistor. Therefore, the coating device 310 can be obtained at a lower cost than when a commercially available general-purpose amplifier is used as the driver 410.

Further, coating apparatus 310 according to the present embodiment.
Driver 410 discharges the electric charge accumulated in the piezoelectric element 326 via the resistor 426 when water is not being ejected. Therefore, the discharge time can be varied by changing the resistance value of the resistor 426. can do.

In this embodiment, the driver 410
In the above, the case where the reference power supply 416 is used to generate a voltage for displacing the piezoelectric element 326 has been described, but the present invention is not limited to this.
An embodiment in which a capacitor 428 having a larger capacitance than the piezoelectric element 326 is applied instead of the reference power supply 416 (FIG. 1)
3). In this case, the capacitor 4
It is necessary to accumulate electric charges so that a voltage capable of displacing the piezoelectric element 326 by a required amount can be generated with respect to.

In this embodiment, NPN transistors 412 and 42 are used as switching elements of the present invention.
4 and the FET 420 have been described, but the present invention is not limited to this.
An NPN transistor may be used instead of the ET 420, and a relay switch may be used instead of the NPN transistor 412.

Further, in the present embodiment, the piezoelectric element 32
The case where the resistor 426 is used to change the discharge time of the electric charge accumulated in the resistor 6 has been described.
Is not always necessary and the lower cost coating device 31
To obtain 0, the resistor 426 may be omitted.

[0100]

As described above, in the solvent coating apparatus according to the first aspect, a driver for driving the piezoelectric element can be constituted by a low-cost switching element. Thus, there is an effect that a low-cost solvent application device can be obtained.

Further, in the solvent coating apparatus according to the second aspect, a driver for driving the piezoelectric element can be constituted by the inexpensive switching element and discharge resistor. Thus, a low-cost solvent coating device can be obtained, and the discharging time of the electric charge stored in the piezoelectric element when the solvent is not ejected is made variable by changing the resistance value of the discharging resistor. Has the effect of being able to

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of an image recording apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic overall configuration diagram of a coating apparatus according to an embodiment of the present invention.

FIG. 3 is an enlarged perspective view of an injection tank according to the embodiment of the present invention.

FIG. 4 is a bottom view showing a state in which a photosensitive material is conveyed below an injection tank according to the embodiment of the present invention.

FIG. 5 is an enlarged view of a main part of FIG. 4;

FIG. 6 is a cross-sectional view of the injection tank according to the embodiment of the present invention, showing a state where a nozzle plate exists at an initial position.

FIG. 7 is a cross-sectional view showing a state in which water is injected from an injection tank according to the embodiment of the present invention.

FIG. 8 is a diagram showing waveforms of a voltage and a displacement amount of a nozzle plate when water is injected from the injection tank according to the embodiment of the present invention.

FIG. 9 is a diagram showing another voltage waveform when water is injected from the injection tank according to the embodiment of the present invention.

FIG. 10 is an enlarged view of a heat development transfer section according to the embodiment of the present invention.

FIG. 11 is a block diagram of a driver for generating a voltage to be applied for displacing a piezoelectric element, and the periphery thereof.

FIG. 12 is a detailed circuit diagram of a driver that generates a voltage applied to displace a piezoelectric element.

FIG. 13 is a detailed circuit diagram of another driver that generates a voltage applied to displace a piezoelectric element.

FIG. 14 is a circuit diagram showing an example of a conventional driver that generates a voltage applied to displace a piezoelectric element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Image recording device 16 Photosensitive material 62 Water application part 310 Application device 312 Injection tank 322 Nozzle plate 324 Nozzle hole 326 Piezoelectric element 400 Controller 406 Microcomputer (signal output means) 410 Driver 412 NPN transistor (switching element) 416 Reference power supply 420 Field effect transistor (switching element) 424 NPN type transistor (switching element) 426 Resistance (discharge resistance) 428 Capacitor

Claims (2)

[Claims] 1. A pressurized chamber filled with a solvent and provided with a nozzle hole, and a piezoelectric element which is displaced by application of a voltage, wherein the pressurized chamber is filled according to the displacement of the piezoelectric element. A solvent application device for ejecting the solvent from the nozzle hole, a signal output unit that outputs a command signal for instructing the timing of ejection of the solvent, and a signal output unit that outputs the command signal to the piezoelectric element based on the command signal. And a switching element for turning on / off the application of a voltage. 2. A pressurized chamber filled with a solvent and provided with a nozzle hole, and a piezoelectric element which is displaced by applying a voltage, wherein the pressurized chamber is filled according to the displacement of the piezoelectric element. A solvent output device that outputs a command signal for instructing a timing of jetting the solvent, wherein the piezoelectric device is electrically connected to the piezoelectric device. A discharge resistor that forms a discharge circuit that discharges the electric charge stored in the element; and, based on the command signal, applying a voltage to the piezoelectric element when the solvent is ejected and applying the voltage to the piezoelectric element and the discharge. A switching element that does not apply a voltage to the piezoelectric element and does not apply a voltage to the piezoelectric element when the solvent is not ejected, and conducts the piezoelectric element and the discharge resistor. Cloth equipment.