JPS6385780A - Process head for electrophotographic device - Google Patents

Abstract

PURPOSE:To prevent the adhesion of unnecessary developer by setting the upper part of an effective image part of a developing part, and the upper part of an effective liquid storage part of a developer tank to the same height, allowing these developing part and developer tank to communicate with each other in the lower part, and supplying the developer to the developing part by gravity. CONSTITUTION:In case of supplying a developer to an electrophotographic film by a developing part 66 and executing development, the upper part of an effective image part of the developing part 66, and the upper part of an effective liquid storage part of a developer tank 126 are set to the same height, these developing part 66 and developer tank 126 are allowed to communicate with each other in the lower part, and a developer is supplied to the developing part 66 by own weight. Accordingly, the developer is not supplied to the upper part than the upper part of the effective image part in the developing part 66, and after a supply of the developer has been stopped, an excess developer is not adhering except to the developing part 66. In this way, the undeserable adhesion of developer surplus to the electrophotographic film is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a process head used in an electrophotographic apparatus to perform various processing on electrophotographic film.

(Prior Art) Electrophotographic apparatuses are known that can record images on predetermined frames of electrophotographic film and project or copy the recorded images.

Further, a process head that is disposed in an electrophotographic apparatus and performs charging, exposure, development, etc. on an electrophotographic film is known from Japanese Patent Laid-open Nos. 59-100479 and 59-162580.

The process head disclosed in the above publication includes a charging/exposure section, a developing section, a drying section, and a fixing section. These parts are arranged adjacent to each other in the above order along the feeding direction of the electrophotographic film, and the arrangement pitch of each part is a constant pitch equal to the frame pitch of the electrophotographic film.

In the charging/exposure section, the electrophotographic film (corresponding to the - frame) located in this section is charged and then exposed to the image light of the original. As a result, an electrostatic latent image corresponding to the image pattern of the original is formed on the electrophotographic film. In the developing section, a liquid developer is applied to the electrophotographic film exposed in the charging/exposure section to visualize the electrostatic latent image.

In the drying section, dry air is blown onto the electrophotographic film moistened with the liquid developer to remove moisture. In the fixing section, the image is fixed on the electrophotographic film by a fixing lamp or the like.

By supplying the developer to the developing section so that it flows down from the upper part to the lower part, the developer does not naturally flow down and excessively adhere to the electrophotographic film.

However, even after the developer supply is stopped, the developer adhering to the developer supply port communicating with the upper part of the developing section may unnecessarily flow down and adhere to the electrophotographic film. This unnecessarily deposited developer causes streaks due to the developer flowing down onto the image surface to which the developer has properly deposited.

[Problem that the invention seeks to solve]

The present invention has been made in consideration of the above facts, and an object of the present invention is to obtain a process head for an electrophotographic apparatus that eliminates unnecessary adhesion of developer.

[Means for solving problems]

The present invention is a process head for electrophotography 'Jli which supplies a developer to an electrophotographic film in a developing section to develop it, comprising:
The upper part of the effective image area of the developing part and the upper part of the effective liquid storage part of the developer tank are made to be at the same height, and the developing part and the developer tank are communicated at the lower part to supply the developer to the developing part by its own weight. It is characterized by

[Effect]

Therefore, in the present invention, the developer is not supplied above the upper part of the effective image area in the developing section, and after the supply of developer is stopped, there is no excess developer attached to areas other than the developing section, resulting in no waste. Necessary excess developer can be prevented from adhering to the electrophotographic film.

〔Example〕

(Electrophotographic Apparatus) FIG. 1 shows an embodiment of an electrophotographic apparatus in which a process head according to this embodiment is disposed.

The electrophotographic device according to this embodiment has a camera function that photographs a document and records the image on an electrophotographic film, a league function that enlarges and projects the image recorded on the electrophotographic film on a screen, and an electrophotographic It has a copy function that enlarges and copies images recorded on film onto copy paper.

The electrophotographic apparatus is constructed by integrating an electrophotographic apparatus main body 10 and a copying apparatus f12 whose housing 11 also serves as a stand for the electrophotographic apparatus main body 10. Note that if the copy function is not required, it is also possible to use only the electrophotographic apparatus main body 10 alone. The housing 14 of the electrophotographic apparatus main body 10 is composed of a portion 14A located on the left and having a substantially rectangular parallelepiped shape, and a portion 14B located on the right and having a stepped top surface. The interior space is communicated at the rear.

On the outside of the housing 14A is a transparent screen 16 that is slightly tilted backwards and covers the front opening of the housing.
is provided, and a document table 18 is provided above. On the document table 18, a transparent glass plate 22 is provided at the bottom of the document holding plate 20, which can be opened and closed, and covers the upper opening of the housing.
(See FIG. 2 below) are arranged. Housing 1
An electrophotographic film 24 (second
A cassette loading section 26 into which a cassette containing a cassette (see figure) is loaded is formed near the center of the top, and a control keyboard 28 for various operations of the electrophotographic apparatus is disposed at the front of the top.

Further, the housing 11 of the copying device f12 has an opening 3 through which copied copy paper 30 (see FIG. 4 described later) is discharged.
2 is formed.

(Optical System of Electrophotographic Apparatus) FIGS. 2 to 4 show the optical system of an electrophotographic apparatus.

As shown in FIG. 2, the photographing optical system includes the document table 1
A document illumination lamp 36 illuminates a document 34, which is a subject set on the glass plate 22 of No. 8 with the document surface facing downward.
and a third mirror 38 on which the reflected light from the original 34 is incident.
, a second mirror 40 into which the reflected light from the third mirror 3 is incident, a first mirror 42 into which the reflected light from the second mirror 40 is incident, and an electrophotograph of the reflected light from the first mirror 42. The main lens 44 is connected to the surface of the film 24.

As shown in FIG. 3, the projection optical system includes a projection light source section 46 that illuminates the electrophotographic film 24, and a main lens 4 that connects the light transmitted through the electrophotographic film 24 to a first mirror 42.
4, a second mirror 40 into which the reflected light from the first mirror 42 is incident, and the screen 16 onto which the reflected light from the second mirror 40 is projected.

As shown in FIG. 4, the copying optical system includes the open-collar projection light source section 46, the main lens 44, the first mirror 42, the second mirror 40, and the space between the main lens 44 and the first mirror 42. a conversion lens 48 that is disposed on the first mirror 42 to slightly reduce the optical image focused on the first mirror 42; and a second mirror 40.
The copy mirror 52 reflects the reflected light from the copying machine 12 toward the copy paper 30 set on the exposure table 50 disposed in the copying apparatus 12.

The main lens 44, the first mirror 42, and the second mirror 40 are commonly used in the three optical systems described above. The main lens 44 and the first mirror 42 are fixedly disposed within the housing 14B of the electrophotographic apparatus main body 10, and the second mirror 40 is fixedly disposed within the housing 14A.

The third mirror 38, copy mirror 52, conversion lens 48 and screen 16 are selectively used.

The third mirror 38 and the copy mirror 52 are movably disposed within the housing 14A of the electrophotographic apparatus main body 10, and the conversion lens 48 is movably disposed within the housing 14B so as not to interfere with other optical systems. has been done. Since the screen 16 does not interfere with other optical systems, it is fixedly arranged as described above.

Further, the optical system of the electrophotographic apparatus includes a main lens 44 and a first lens.
A shutter controlled by an automatic exposure control device is disposed between the mirror 42 and the mirror 42 .

(Process Head) FIGS. 5 to 13 show an embodiment of a process head according to the present invention disposed in the electrophotographic apparatus.

As shown in FIGS. 5 and 6, the process head 5
4 is constructed by integrating a relatively flat, generally rectangular parallelepiped-shaped main body part 56 and a pair of legs 58 located at the lower part of the main body part 56, and is integrally molded with synthetic resin except for the attachments. has been done. The process head 54 is disposed between the main lens 44 and the electrophotographic film 24 shown in FIGS. 2 to 4, and as shown in FIG. It is attached to a frame 60 disposed within the housing 14B of the device main body IO.

The main lens 44, as shown in FIGS. 5 and 7,
It is assembled into the lens barrel 62 and attached to the head surface of the process head 54. The electrophotographic film 24 is constructed by sequentially laminating a transparent conductive layer, an intermediate layer, and a photosensitive layer on a support such as polyethylene, and the photosensitive layer consists of a photoconductive layer and a protective layer that protects the photoconductive layer. It is configured. The electrophotographic film 24 is in the form of a long tape and is housed inside a cassette case.

As shown in FIG. 6, the electrophotographic film 24 includes:
Blip marks 2 are placed on the top edge at regular intervals along the longitudinal direction.
4A is printed. The blip marks 24A are provided corresponding to the edges of the image recorded on the electrophotographic film 24. The electrophotographic film 24 is moved in the width direction of the process head 54 (in the left-right direction in FIG. ). Further, the transparent conductive layer of the electrophotographic film 24 can be electrically connected to the electrophotographic apparatus main body 10 when the cassette is loaded into the electrophotographic apparatus main body 10. It goes without saying that the electrophotographic film is not limited to the above-mentioned embodiments, and any known film can be used.

The main body 56 of the process head 54 includes
As shown in the figure, charging/exposure sections 64 are sequentially arranged in the width direction.
, a developing section 66, a drying section 68, and a fixing section 70 are formed at a constant pitch corresponding to the pitch of the electrophotographic film 24.

(Charging/Exposure Section) As shown in FIGS. 7 and 8, the charging/exposure section 64 has a charging/exposure chamber 72 formed in an internal space on the back side of the front wall 74 of the process head 54. The charging/exposure chamber 72 has an opening in the front wall 74 of the process head 54, and around this opening, as shown in FIGS. mask 76
The opening shape of this mask 76 is a rectangular shape corresponding to the size of the gobo of the electrophotographic film 24. The charging/exposure chamber 72 includes a corona unit 78,
Proximity electrode 80 and mask electrode l! i82 is installed.

As shown in FIG. 5, the corona unit 78 includes a corona wire 84 and a synthetic resin holder 86 that holds the corona wire 84, and is inserted into the process head 54 from above. The proximal electrodes 80 are composed of narrow metal plates and are arranged on both sides of the corona wire 84. The mask electrode 82 is formed by bending a metal plate into a rectangular shape, and is disposed near the opening of the front wall 74.

The corona wire 84 is connected to a high voltage power source and the proximal electrode 80
and the mask electrode 82 are electrically connected. Normally, the proximal electrode 8fl is directly connected to the ground, and the mask electrode 82 is connected to the ground via an electrical resistance.
Different bias voltages may be applied from an external power supply.

As shown in FIG. 7, a film cooling air outlet 88 is opened in the charging/exposure chamber 72, and cool air is supplied from an air pump 89 through a conduit 87.

The main lens 44, which is assembled into the lens barrel 62 and attached to the back surface of the process head 54 as described above, has its front axis aligned with the center of the opening of the mask 76.

Note that this charging/exposure section 64 has a guide protrusion 77 projecting above the mask 76 and having a longitudinal direction extending laterally.

This guide protrusion 77 is at the same height as the mask 76 so that when the electrophotographic film 24 is loaded into the cassette loading section 26 together with the cassette, the front wall 74 of the process head main body section 56 does not get caught on the mask 76. ing. For this reason, the upper and lower sides of this guide protrusion 77 form inclined surfaces whose height gradually decreases.

(Developing Section) The developing section 66 includes, as shown in FIGS. 5 and 6,
A mask 90 is formed, and the mask 90 covers the upper frame 9.
0A and left and right frames 90B and 90C stand up from the surface of the recess 92 formed in the front wall 74. The lower side of the lower frame 900 of the mask 90 stands up from the front wall 74. Further, the bottom frame 90D has left and right frames 90B, 90 at both ends.
It further extends in the left-right direction from the connecting portion with C.

The protruding height of the mask 90 is set to be at the same level as the mask 76.

The opening width of the mask 90 is made very slightly shorter than the opening width of the mask 76. In addition, the opening height of the mask 90,
That is, the distance between the inner walls of the upper frame 90A and the lower frame 90D is
The inner wall of the lower frame 900 is located lower than that of the mask 76, and is lengthened by that amount.

A developing electrode 96 is disposed within the opening of the mask 90 and supported by a rear wall 94, as shown in FIG. Developing electrode 96 is connected to a bias power source. The surface of the developing electrode 96 is located slightly inside from the end surface of the mask 90, and a space surrounded by the developing electrode 96 and the inner wall of the mask 90 is defined as a developing chamber 98. The upper and lower parts of the developing electrode 96 are opened, and each has an air inlet 1 for squeezing.
00 and a developer inflow/outflow port 102.

The wall surface of the developing chamber mask 90 is smoothed to improve the efficiency of liquid removal.

The squeeze air inlet 10G communicates with a passage 104 formed in the internal space of the process head 54.The squeeze air inlet 10G communicates with a squeeze air supply port 106 opened at the back of the process head 54 and an atmospheric supply 0108. ing. Further, the developer inflow/outflow port 102 is communicated with a passage 110 formed in the internal space of the process head 54 .

The passage 110 communicates with a developer inlet/outlet 112 opened on the back side of the process head 54 .

As shown in FIGS. 6 and 10, the recesses 92 located on both sides of the left and right frames 90B and 90C of the mask 90 are opened at the bottom and serve as squeeze suction ports 1l4. As shown in FIG. 10, the squeeze suction port 114 is
Passage 116 constituted by the internal space of process head 54
It is communicated with.

As shown in FIG. 11(A), the developer/squeeze air outlet 112 is connected to the pipe line 1 through a solenoid valve 120 in the middle.
It is connected to a developer tank 126 at 22 . The developer tank 126 is located above the solenoid valve 120. The developer tank 126 is connected to a developer pump 130 driven by a motor 128 through a conduit 132. The developer supply pump 130 is disposed in the developer bottle 134. The developer bottle 134 contains a developer 136 in which toner particles are dispersed in a solvent.

The pipe line 122 is branched in the middle to form a return pipe line 138 that opens into a developer bottle 134 .

A partition wall 24 is provided inside the developer tank 126. The partition wall 124 stores the developer 136 supplied through the pipe line 132 and supplies it to the pipe line 122, while overflowing the excess developer 136 and passing it through the return pipe line 140 to the developer bottle 134. It is designed to return to.

Therefore, within the developer tank 126, the area up to the upper end of the partition wall 124 is an effective storage area for the developer 136, and the height of the upper end of this partition wall 124 is the effective image area of the developing chamber 98 in the process head 54. It is at the same height as the top edge of. As a result, from the developer tank 126 to the pipe line 122,
The developer supplied to the developing chamber 98 through the passage 110 is configured so that it is not supplied above the upper end of the developing chamber 98.

The atmosphere supply port 108 is communicated with the atmosphere via a conduit 142 and a solenoid valve 144. Therefore, when the electromagnetic valve 144 is opened, the pressure in the passage 104 becomes atmospheric, and the developer in the developing chamber 98 naturally flows down to a blisque state.

A squeeze pump 148 is communicated with the developer supply port 106 via a conduit 146 to forcefully flow down the developer after development.

A conical plate 150 is mounted on the upper part of the developer bottle 134, and the lower end of this plate 150 is attached to the developer bottle 134.
A small amount enters the inside, and the bottom surface is the developer bottle 13.
4 and closes the developer bottle 134.

A developer pump 1 passes through the central opening of the dish plate 150.
30 is lifted by the motor 128, the plate plate 1
50 is engaged with the lower end of the developer pump 130 and raised, and the lower end of the dish plate 150 is removed from the developer bottle 134, allowing the developer bottle 134 to be replaced.

When the plate 150 rises, it slides inside the cylindrical part 154 that hangs down from the support +ffl 152, and when the plate 150 is lowered to the position shown in FIG. Tapered elastic membrane 156
The lower end protrusion 158 comes into contact with the developer bottle 134.
It is designed to seal the inside from the outside air.

As shown in FIG. 11(B), the suction squeeze opening 118 is connected to a suction trap 238 through a conduit 236. The suction trap 238 is connected by a conduit 240 to an air pump 242 for suction squeeze. Further, a return pipe 244 that opens into the developer bottle 134 is connected to the bottom of the suction trap 238 . suction trap 2
38 is provided with a valve 246 that can close the return pipe line 244 at a connection part with the return pipe line 244.
46 is moved up and down by a solenoid 250 via a shaft 248.

Note that the process head 54 is shown tilted in FIG. 11 because it is tilted with respect to the horizontal plane so that the optical axis of the optical system is perpendicular to the screen 16 arranged tilted. .

(Drying section) The drying section 68 includes, as shown in FIGS. 5 and 6,
A frame wall 164 is formed. The frame wall 164 is the upper frame 1
64A and left and right frames 164B and 164C, there is no lower frame.The main frame 164B is continuous from the right end of the lower frame 90D of the mask 90, and the upper frame 164
It stands up from the front wall 74 together with A. Further, the cloth frame 164C rises from a front wall recess 168 that is depressed from the front wall 74 in a step-like manner.

7 and 12 between the left and right frames 164B and 164C.
As shown in the figure, a wall 170 whose surface is located slightly inward from the end face of the frame wall 164 is formed, and furthermore, recesses 172 are formed on both sides of this wall 170. The bottom surface of the recess 172 is located at a position protruding from the wall surface of the full-wall recess 168. A space surrounded by the frame wall 164, wall 170, and recess 172 is a drying chamber 174. The inner width of the frame wall 164 is wider than the opening width of the mask 90. Also, the lower surface (inner surface of the frame) of the upper frame 164A
is located above that of the mask 90 of the developing section 66.

As shown in FIGS. 6 and 12, the upper frame 164A
The lower part is opened and serves as a hot air outlet 176. As shown in FIG. 12, the hot air outlet 176 communicates with a passage 178 formed in the internal space of the process head 54. The zero passage 178 is a hot air supply opening opened on the back side of the process head 54. 0 passage 1 connected to 180
A temperature sensor 182 is disposed at 78 . The hot air supply port 180 is connected to the heater 179 and the air pump 1 through a conduit 177.
81 to supply hot air.

(Fixing Unit) As shown in FIGS. 5 to 7, the fixing unit 70 is formed between the cloth frame 164C of the frame wall 164 and the front wall 74 located at the right end.

The fixing section 70 has a frame section 184 formed of a lower frame and left and right frames at a position further depressed from the front wall recess 168. A transparent glass plate 186 is provided in the frame portion 184.
is fitted, and the space in front of the glass plate 186 is used as a fixing chamber 188.

As shown in FIG. 13, in the space 190 of the process head 54 formed on the back side of the glass plate 186,
A xenon lamp 192 and a reflection plate 194 are provided. A cooling air outlet 196 is opened in the space 190,
Cold air is supplied from an air pump 195 via a conduit 193. The space 190 and the fixing chamber 188 communicate with each other above the glass plate 186.

(Blip sensor) As shown in FIGS. 5 and 6, the process head 5
4, a blip sensor 196 is installed at the left end of the front wall 74.
is installed. The blip sensor 196 detects the electrophotographic film 2 being moved along the front surface of the process head 54.
It is located at a height where the blip mark 24A of No. 4 passes, and when the blip mark 24A passes, the light from the light source for the sensor, which is placed facing each other with the electrophotographic film 24 in between, is blocked. I'm starting to know.

(Film Holding Mechanism) As shown in FIGS. 7 and 14, a holding plate 198 is provided in front of the front wall 74 of the process head 54. As shown in FIGS. The presser plate 198 has, as shown in FIG.
A rectangular through hole 200 having a size slightly smaller than the opening shape of the mask 76 formed in the charging/exposure section 64 is formed.

The holding plate 198 is arranged so that the through hole 200 corresponds to the mask 76.

A cylindrical portion 212 is formed protrudingly on the back surface of the presser foot 198 facing the process head 54.
12 has a notch 21 formed at one end of the arm 214.
4A is engaged. A retaining ring 212A is fixed to the tip of the cylindrical portion 212 to prevent the cutout portion 214A from being pulled out. A boss portion 214B is formed at the other end of the arm 214. The shaft 21 is attached to the boss portion 214B.
6 is fixed.

The shaft 216 is rotatably inserted into and supported by a stand 218 erected on the frame 60 to which the process head 54 is attached, and its lower end protrudes from the back surface of the frame 60 . A third lever 220 is fixed to the lower end of the shaft 216.

A pin 222 is fixed to the tip of the first lever 220.

On the other hand, a shaft 224 is vertically provided on the back surface of the frame 60. An intermediate portion of a second lever 226 is rotatably supported on the shaft 224 . The pin 222 is engaged with a notch 226A formed at one end of the second lever 226. A long hole 22 formed at the other end of the second lever 226
6B is a tension coil spring 2 that urges the second levers 226 in opposite directions and elastically supports the second levers 226.
28, 230 are locked at one end.

The other end of the tension coil spring 228 is locked to a pin 232 vertically installed on the back surface of the frame 60, and the other end of the tension coil spring 228 is attached to a pull-type pin 232 installed on the back surface of the FuC-Muro 0. It is locked to a plunger 234A of a solenoid 234.

The presser plate 198 is spaced apart from the process head 54 when the solenoid 234 is not energized. In this state, as shown in FIG. 14, the cylindrical portion 206 of the holding plate 198 is fitted into the hole 210 formed in the process head 54 and supported.

When solenoid 234 is energized, plunger 234A
is actuated in the direction of arrow A, and the tension coil spring 228.23
0 is stretched against the force.

As a result, the second lever 226 is rotated about the shaft 224 in the direction of arrow B, so that the second lever 220 is rotated around the shaft 224.
22 in the direction of arrow C, causing the shaft 216 to rotate in the same direction. The rotation of the shaft 216 causes the arm 214 to rotate in the direction indicated by the arrow, and presses the presser plate 198 in the direction indicated by the arrow E.

The presser plate 198 is moved in the direction of arrow E with the cylinder portion 206 guided by the hole 210, and presses the electrophotographic film 24 into contact with the mask 76, 90 and the end face of the frame □ wall 164. When the presser plate 198 is moved, the electrophotographic film 24
If the position of the claw 20 is incorrect in the height direction,
The inclined surfaces 202A and 204A of 2.204 act to push down the upper edge of the electrophotographic film 24 or push up the lower edge thereof.

When the holding plate 19B presses the electrophotographic film 24 against the process head 54, the holding plate 19B has claws 202 and 204.
are fitted into holes 208, 210 and accurately positioned in process head 54. Also, the presser plate 198
In this state, the electrophotographic film 24 is elastically pressed by the action of the tension coil springs 228 and 230.

When the solenoid 234 is demagnetized, the tension coil spring 22
8, the second lever 226 is rotated in the direction opposite to the arrow B, the arm 214 is rotated in the direction opposite to the arrow B, the notch 214A presses the retaining ring 212A, and the retaining plate 19B is rotated.
is moved in the opposite direction of arrow E.

(Effect of Example) Next, the operation of this embodiment will be explained.

When the power switch of the electrophotographic device is turned on, the first
The cassette loading section 26 shown in the figure is raised, and a cassette containing the electrophotographic film 24 can be loaded. After the cassette is loaded into the cassette loading section 26, when the cassette loading section 26 is manually pushed down to its original position, the cassette loading section 26 is restrained at that position. In this state, the electrophotographic film 24 is positioned as shown in FIG. 14, and can be moved along the front surface of the process head 54 by driving a film moving motor (not shown).

When recording the image of the document 34 shown in FIG. 2 on the electrophotographic film 24, a film moving motor (not shown) is driven to move a predetermined frame freely selected from among the frames that have not yet been recorded. is positioned in front of the mask 76 of the charging/exposure section 64. This operation is performed by specifying a predetermined frame using the control keyboard 28 shown in FIG. It is controlled by

In the process head 54, when the frame located in the charging/exposure section 64 is charged and exposed, the developing section 66 and the drying section 6
8. The frames located in the fixing section 70 are subjected to different processes simultaneously.

The image of the document 34 is made possible by selecting the camera mode by operating a button on the control keyboard 28. At the same time, the developing electrode 96 of the developing section 66 is energized to apply a bias voltage, and the drying chamber A heater 179 that heats the air blown to the heater 174 is energized and generates heat, and a capacitor of a xenon lamp 192 in the fixing section 70 is energized and charged. These continue while the camera mode is selected.

When the shadow button on the control keyboard 28 is pressed, the corona wire 84 of the charging/exposure section 64 is energized and a high voltage is applied, generating corona discharge between the proximal electrode 80 and the mask electrode 82. As a result, the mask 76
The surface of the photosensitive layer of the electrophotographic film 24 located within the aperture frame is charged to e.

Note that at the time when the shadow button is pressed, the solenoid 234 of the film holding mechanism is energized continuously from the previous process, and the electrophotographic film 24 is pressed against the holding plate 198 and the mask 76, 90 of the process head 54 is pressed. and frame wall 16
4 and is pressed into contact with each end face of 4. The presser plate 198 has a through hole 200 formed in a portion corresponding to the mask 76, but since the through hole 200 is smaller than the opening of the mask 76, the electrophotographic film 24 located on the end surface of the mask 76 is pressed by the presser plate surface around the through hole 200. Therefore, the electrophotographic film 24 is reliably brought into close contact with the end face of the mask 76, so that the charging range is precisely the same as that of the mask 76.
The opening range is limited to 6.

In addition, a mask electrode 82 provided in the charging/exposure chamber 72
is held at approximately the same potential as the charged potential of the electrophotographic film 24, so that the peripheral edge of the gobo of the electrophotographic film 24 located in the opening of the mask 76 is also charged to a value close to the potential of the center of the frame. , the entire surface of the electrophotographic film 24 is uniformly charged. By appropriately selecting the value of a resistor (not shown) interposed and electrically connected between the ground and the mask electrode 82, or by
2 from an external power source (not shown), the mask electrode 82 is connected to the electrophotographic film 24.
can be maintained at a potential approximately equal to the charging potential of .

! ! After a predetermined period of time has elapsed after the shadow button is pressed, the document illumination lamp 36 is turned on, and the document 34 placed on the glass plate 22 of the document table 18 is illuminated. Furthermore, after a predetermined period of time has elapsed after the button is pressed, the current supply to the corona wire 84 is stopped, and the corona discharge ends.

At the same time as the power supply to the corona wire 84 is stopped, a shutter (not shown) is opened, and the optical system shown in FIG. ! Image light from the placed original 34 is irradiated onto the electrophotographic film 24. Furthermore, at the same time, an automatic exposure control device (not shown) starts integrating the amount of light.

On the other hand, after a predetermined period of time has elapsed after the button is pressed, the first
The motor 128 shown in FIG. 1A is driven to start operating the developer pump 130, and the developer bottle 13
The developer 136 in the developer tank 126 is pumped up into the developer tank 126. The developer 136 descends from the developer tank 126 under its own weight, energizes the pipe 124, and heads toward the process head 54, but at this time, the solenoid valve 120 is still closed, so it overflows from the partition wall 124 and enters the return pipe. 140 and is returned to the developer bottle 134.

In this way, the developer 136 circulates between the developer bottle 134 and the developer tank 126 and waits at a position immediately in front of the solenoid valve 120 until the solenoid valve 120 is opened. With this v11 ring, the developer bottle 13
The developer 36 in 4 is stirred.

When the cumulative value of the light amount of the automatic exposure control device reaches the set value, the cumulative value is stopped, the shutter is simultaneously closed, and the document illumination lamp 36 is turned off. At this point, the exposure process is complete, and the portion of the electrophotographic film 24 located in the opening of the mask 76 is electrostatically charged due to the electric charge on the photosensitive layer being reduced in accordance with the image pattern of the original 34. A latent image is formed. Manuscript 34 bottom i! ! ! The factors that cause image 4 degree fluctuations, such as variations in density and fluctuations in the voltage applied to the document illumination lamp 36, are corrected by the automatic exposure control device, so that proper exposure is always performed. At this time, when a predetermined time has elapsed since the button was pressed and all processing steps for other frames have been completed, the solenoid 234 of the film holding mechanism is immediately demagnetized. When the solenoid 234 is demagnetized, the presser plate 198 is separated from the electrophotographic film 24.

At the same time that the solenoid 234 of the film holding mechanism is demagnetized, the solenoid 250 of the suction trap 238 shown in FIG.
The valve 246 is raised through the valve 246 and the return line 244 is communicated with the suction trap 238 . As a result, the developer 136 that was captured in the suction trap 238 during the previous development and squeeze process is returned to the developer bottle 134.

After the solenoid 234 of the film holding mechanism is demagnetized,
After a predetermined period of time has elapsed, a film moving motor (not shown) is driven to move the electrophotographic film 24 toward the right in FIG.
Moved by 1. As a result, the frame located in the charging/exposure section 64 is moved to the developing section 66. One frame movement of the electrophotographic film 24 is controlled by the prep sensor 196 detecting the blip mark 24A, as in the case described above.

When the solenoid valve 120 is opened, the developer 136 flows into the conduit 122.
, passes through the passage 11G, reaches the process head 54, and flows into the developing chamber 98 from the developer/squeeze air outlet 102 of the developing section 66. The toner particles dispersed in the developer 136 are charged to e, and in the process of flowing down the developing chamber 98, they adhere to the portion of the electrophotographic film 24 that is charged to Φ, and develop an electrostatic latent image. become

In this case, from the developer pump 130 to the developer tank 1
26 is always supplied to the partition wall 124.
The developer is supplied so as to overflow from the upper end, so that the developer supplied through the pipe line 122 is supplied to the developing chamber 98 up to the same level as the upper end of the partition wall 124 . However, the developer in the developing chamber 98 does not rise above this level.

Next, solenoid valve 120 is closed and solenoid valve 144 is opened. This brings the developing chamber 9B to atmospheric pressure, so the developer in the developing chamber 98 is returned to the developer bottle 134 through the conduit 122 and the return conduit 138.

The developer 136 flowing down the developing chamber 98 is
Since the electrophotographic film 24 is pressed into contact with the end surface of the mask 90 at step 8, it hardly enters the gap between the end surface of the mask 90 and the electrophotographic film 24.

1 located on both sides of the left and right frame parts 90B and 90C of the
When the magnetic valve 144 is closed, the squeeze pump 148 for pressure squeezing is activated, and pressurized air is supplied to the developing chamber 98, so that the excess developer 136 in the developing chamber 98 is removed from the passage 110 and the pipe 122. and is returned to the developer bottle 134. In this case, developer supply port 106, passage 1
Since the pressurized air passing through 04 and reaching the developing chamber 98 does not have developer attached above the effective image area of the developing chamber 98, excess developer is not unnecessarily applied to the image surface.

Note that during development, the presence of the development electrode 96 makes it possible to obtain an image free of edge effects. Further, since a bias voltage is applied to the developing electrode 96, image fogging is prevented. Image reproducibility can also be improved by applying a pulsed high voltage having the same polarity as the charging polarity of the toner particles during development.

When the film movement mode and the evening drive are stopped, the electrophotographic film 24 is moved by -1 to the right in FIG. After a predetermined period of time has elapsed after the film moving motor is stopped, the solenoid 234 of the film holding mechanism is energized, and at the same time,
Air pump 18.1 of FIG. 12 is activated and line 177
The hot air heated by the heater 179 is blown out from the hot air outlet 176 of the drying section 6B to the drying chamber 174, and the developer 136 is dried.

Note that the warm air supplied to the drying chamber 174 is detected by the temperature sensor 18.
2, its conductivity is detected and the temperature is controlled to be constant.

Since the drying chamber is larger than the developing chamber, the film wet with the developer can be completely dried to the periphery.

In addition, in the above example, solenoid 2 of the film holding mechanism
34, the drying air pump 181 was operated only when pressing the electrophotographic film 24 against the process head 54 (), but the air pump 181 may be operated continuously from the start. After the solenoid 234 of the film holding mechanism is demagnetized,
The film moving motor is driven, and the frames located in the drying section 6B are moved to the fixing section 70. After the drive of the film moving motor is stopped, the solenoid 234 of the film holding mechanism is energized, and at the same time, the air pump 195 shown in FIG.
Cold air is supplied to 0. This cold air passes through the upper part of the glass plate 186 from the space 190 and reaches the fixing chamber 188 .

After a predetermined period of time has elapsed since the solenoid 234 of the film holding mechanism was energized, the xenon lamp 192 emits light.
The toner particles are fused and fixed to the surface of the electrophotographic film 24, completing the fixing process.

Air pump 19 removes vaporized substances and scattered substances generated during fixing.
Since the particles are blown off by the cold air supplied by the operation of step 5, they do not adhere to the surface of the glass plate 186.

By completing the above steps, recording of the image on the electrophotographic film is completed.

〔Effect of the invention〕

As explained above, in the present invention, the upper part of the effective image area of the developing section and the upper part of the effective liquid storage part of the developer tank are set at the same height and communicated with each other so that the developer is supplied to the developing section by its own weight. It has an excellent effect of preventing the developer from adhering to the image area.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view showing an embodiment of an electrophotographic device;
The figure is a perspective conceptual diagram showing the imaging optical system of an electrophotographic device.
FIG. 4 is a perspective conceptual diagram showing a projection optical system, FIG. 4 is a perspective conceptual diagram showing a copying optical system, and FIG. 5 is a process head according to an embodiment of the present invention installed in the electrophotographic apparatus shown in FIG. 1. Figure 6 is a front view, and Figure 7 is an exploded perspective view of the same.
Fig. 8 is a view taken along the line ■-■ of Fig. 6, Fig. 9 is a view taken along the IX-IX line of Fig. 6, and Fig. 1O is a view taken along the line IX-IX of Fig. 6. 11 (A) and (B) are explanatory diagrams showing the relationship between the process head developing section and other equipment, and FIG. 12 is a view taken along the xn-xu line in FIG. 6. , Figure 13 is the 6th
Fig. 14 is a schematic side view showing the positional relationship between the process head and the holding plate, Fig. 15 is a perspective view showing the film holding mechanism installed in the process head, Fig. 15A The figure is a perspective view of some parts of FIG. 15 viewed from the opposite side. 66...Development section, 9B...Development chamber, 124...Partition wall, 126...Developer tank.

Claims (1)

[Claims] (1) A process head for an electrophotographic device that supplies developer to an electrophotographic film in a developing section to develop the film, wherein the upper part of the effective image area of the developing part and the upper part of the effective liquid storage part of the developer tank are connected to each other. A process head for an electrophotographic apparatus, characterized in that the height is the same, the developing section and a developer tank are communicated at the bottom, and the developer is supplied to the developing section by its own weight.