JPH0528832B2 - - Google Patents

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.

[Conventional technology]

2. Description of the Related Art Electrophotographic apparatuses are known that are capable of recording images on predetermined frames of electrophotographic film and projecting or copying the recorded images.

Furthermore, a process head which 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 for an electrophotographic apparatus disclosed in the above-mentioned publication includes a mask made of an insulating material and having an opening formed inside thereof to limit the charging area of the electrophotographic film, and a corona wire disposed facing the opening. A charging unit is configured with a corona discharge generating means such as the above. The electrophotographic film is designed so that only a specific portion (a portion corresponding to one frame in the case of a long electrophotographic film) is charged by this charging section.

In electrophotographic film, a conductive layer and a photoconductive layer are sequentially laminated on a support, and when charged, the surface of the photoconductive layer is brought into contact with the surface of a mask and faces a corona discharge generating means. There is.

By the way, in the conventional process head for forming microfilm images as described above, the charging section also serves as the exposure section, and charging and exposure are performed while the electrophotographic film and the corona discharge generating means are relatively stationary. In this case, the mask limits the range of image light irradiated onto the electrophotographic film.

When charging is performed in the process head as described above, the mask portion that is in contact with the electrophotographic film is also charged to a high potential during charging. After being charged, when the image area of the electrophotographic film is exposed to image light, the periphery of the image area is at a low potential because in a normal original document, there are no characters or the like around the periphery of the original and there is a blank space. Become. Under such conditions, when the electrophotographic film in contact with the process head is moved by one frame, the charge of the highly charged mask portion is transferred to the image area, and this transfer is caused by the development. When this happens, it becomes a black spot-like stain. These black spot-like stains are caused by the wet process of electrophotographic film, in which charging and exposure are performed at the same location, and in order to charge a single frame in a narrow area, especially on microfilm, a charging mask is used electronically. This is particularly likely to occur with process heads that are designed to come into contact with photographic film.

This problem can be solved by exposing the electrophotographic film to light while separating it from the mask after charging. However, it is difficult to ensure the positional accuracy of the electrophotographic film with respect to the mask, and it is difficult to ensure focal length accuracy during exposure with the electrophotographic film separated from the mask, so it is practically impossible to adopt this method. It is difficult to do so.

Furthermore, if a separate exposure chamber is provided and the film is moved and exposed after being charged, black spot stains are less likely to occur than when the charging and exposure chamber is also used, but this is not a complete problem.

[Problem that the invention seeks to solve]

In consideration of the above-mentioned facts, the present invention creates an electron beam that creates a shadow against corona discharge by the notch, prevents the mask edge portion that comes into contact with the electrophotographic film from being charged, and eliminates the generation of black spot-like stains due to discharge. The purpose is to obtain a process head for photographic equipment.

[Means for solving problems]

The process head for an electrophotographic apparatus according to the present invention includes a mask that is made of an insulator and has an opening formed inside thereof to limit the charged area of the electrophotographic film, and the surface of which the electrophotographic film is brought into contact, and a mask that faces the opening. and a corona discharge generating means for charging an electrophotographic film located in the opening, and the opening of the mask is wider on the mask surface side than on the corona discharge generating means side.

[Effect]

According to the present invention, the mask is formed of an insulator, and the opening of the mask is wider on the side of the abutting surface (surface) of the electrophotographic film than on the side of the corona discharge generating means. Therefore, the area of the electrophotographic film placed in the aperture is slightly wider than the area of the image frame.

In this state, when corona is discharged from the corona discharge generating means, the surface of the electrophotographic film corresponding to the opening is charged to one pole (for example, positive).
At this time, since the mask is made of an insulator, charging due to corona discharge is limited to a range connected approximately in a straight line from the discharge point of the corona discharge generating means (strictly speaking, there is a slight detour).
Since the wide-opening portion on the side of the contact surface of the electrophotographic film is outside the charging area, that is, in the shadow, the charging area is limited to an area slightly smaller than the mask opening. In other words, charging is suppressed in the contact area between the mask and the electrophotographic film and in the vicinity thereof.

Thereby, it is possible to prevent the developer (for example, toner particles) from transferring to the peripheral portion of the mask opening during image exposure. Further, even when the electrophotographic film is transported after exposure, toner particles are not transferred to the peripheral edge of the image frame.

〔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 apparatus according to this embodiment has a camera function that photographs a document and records the image on an electrophotographic film, a reader function that enlarges and projects the image recorded on the electrophotographic film onto a screen, and an electrophotographic It also 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 12 in which a 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, a slightly tilted transmissive screen 16 is disposed to cover the front opening of the housing, and a document table 18 is disposed above. On the document table 18, a transparent glass plate 22 (see FIG. 2, which will be described later) is disposed below a document holding plate 20 that can be opened and closed, and covers the upper opening of the housing. On the outside of the housing 14B, a cassette loading section 26 into which a cassette containing an electrophotographic film 24 (see FIG. 2 described later) is loaded is formed near the center of the upper part, and an electrophotographic device is mounted at the front of the upper part. A control keyboard 28 is provided for performing various operations.

Further, the housing 11 of the copying device 12 is formed with an opening 32 through which copied copy paper 30 (see FIG. 4 described later) is discharged.

(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 an original illumination lamp 36 that illuminates an original 34, which is a subject set on the glass plate 22 of the original table 18 with the original surface facing downward; a third mirror 38 into which the reflected light is incident, and a third mirror 38
A second mirror 40 to which the reflected light from the second mirror 40 is incident, a first mirror 42 to which the reflected light from the second mirror 40 is incident, and the reflected light from the first mirror 42 is connected onto the surface of the electrophotographic film 24. A main lens 44 is provided.

As shown in FIG. 3, the projection optical system includes a projection light source section 46 that illuminates the electrophotographic film 24;
A main lens 44 connects the light transmitted through the electrophotographic film 24 to a first mirror 42, a second mirror 40 receives the reflected light from the first mirror 42, and the reflected light from the second mirror 40 is projected. The screen 16 is also provided.

As shown in FIG. 4, the copying optical system includes a projection light source section 46, a main lens 44, a first mirror 42, a second mirror 40, as well as a main lens 44.
A conversion lens 48 is disposed between the first mirror 42 and the first mirror 42 to slightly reduce the optical image focused on the first mirror 42, and a conversion lens 48 is disposed between the second mirror 40 and the second mirror 40 to reflect light from the second mirror 40 to the copying device 12. exposure table 50
The mirror 52 is provided with a copy mirror 52 that reflects the image toward the copy paper 30 set in the mirror.

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 connected to the housing 14 of the electrophotographic apparatus main body 10.
The conversion lens 48 is movably disposed within the housing 14B so as not to interfere with other optical systems.
Since the screen 16 does not interfere with other optical systems,
It is fixedly arranged as described above.

In addition, the optical system of an electrophotographic device includes a main lens 4.
4 and the first mirror 42, a shutter controlled by an automatic exposure control device is disposed.

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

As shown in FIGS. 5 and 6, the process head 54 includes a relatively flat, substantially rectangular parallelepiped main body 56 and a pair of legs 58 located at the bottom of the main body 56. It is made of synthetic resin and is integrally molded except for the attachments. 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. Housing 14B of device main body 10
It is attached to a frame 60 located inside.

The main lens 44 is assembled into a lens barrel 62 and attached to the back surface of the process head 54, as shown in FIGS. 5 and 7. 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 in a cassette case.

As shown in FIG. 6, the electrophotographic film 24 has blip marks 24A printed on its upper end at regular intervals along the longitudinal direction. The blip mark 24A is provided corresponding to one frame of an 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. ). In addition, electrophotographic film 24
The transparent conductive layer of the cassette is the electrophotographic apparatus main body 10.
When loaded into the electrophotographic apparatus main body 10, electrical connection can be established. It goes without saying that the electrophotographic film is not limited to the above-mentioned embodiments, and any known electrophotographic film can be used.

As shown in FIGS. 5 to 7, the main body portion 56 of the process head 54 includes a charging/exposure portion 64, a developing portion 66, a drying portion 68, and a fixing portion 70 in order in the width direction. It is formed at a constant pitch corresponding to one frame interval.

(Charging/Exposure Section) As shown in FIGS. 7 and 8, the charging/exposure section 64 includes a front wall 74 of the process head 54.
A charging/exposure chamber 72 is formed in the internal space on the back side of the . The charging/exposure chamber 72 is located in the process head 5
4, and around this opening, as shown in FIGS. 5 and 6,
A mask 76 is formed that slightly protrudes from the front wall 74. The opening shape of this mask 76 is a rectangular shape corresponding to one frame of the electrophotographic film 24, and more specifically, the shape is as shown in FIG. 17.

FIG. 17A is an enlarged front view of the mask 76, and FIG.
17A is a view taken along the line BB in FIG. 17A, and FIG. 17C is a partially detailed enlarged view of FIG. 17B. mask 76
, the inner corner of the end surface 76A on the mask surface side against which the electrophotographic film 24 comes into contact is cut out, and the mask opening widens from the inside to the outside of the process head 54 in the vicinity of the end surface 76A. It is said to have the shape of As shown in FIG. 17C, the shape and dimensions of this notch are such that the opening depth U from the opening position S on the inner side of the process head 54 to the opening position T on the end face 76A side is 0.2 mm. . Also,
The difference V in opening length between the opening position S and the opening position T is also 0.2 mm. The shape and dimensions of this notch are the same on all four inner circumferences of the mask 76.

The charging/exposure chamber 72 includes a corona unit 78,
A proximity electrode 80 and a mask electrode 82 are provided. As shown in FIG. 5, the corona unit 78 is composed of 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. Corona wire 84 is connected to a high voltage power source,
Proximity electrode 80 and mask electrode 82 are electrically connected. Normally, the proximal electrode 80 is directly connected to ground, and the mask electrode 82 is connected to ground via an electrical resistance, but different bias voltages may be applied to each from an external power source.

As shown in FIG. 7, a film cooling air outlet 88 is opened in the charging/exposure chamber 72, and cool air is supplied by an air pump 89 through a conduit 87. The main lens 44 assembled into the lens barrel 62 and attached to the back surface of the process head 54 as described above has its optical axis aligned with the mask 7.
It coincides with the center of the opening of No. 6.

(Developing Section) As shown in FIGS. 5 and 6, a mask 90 is formed in the developing section 66.
0, the upper frame 90A and the left and right frames 90B and 90C rise from the surface of the recess 92 formed in the front wall 74. The lower side of the lower frame 90D of the mask 90 stands up from the front wall 74. Further, both end portions of the lower frame 90D extend further in the left-right direction from the connecting portions with the left and right frames 90B and 90C.
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. Also, mask 9
0 opening height, that is, the upper frame 90A and the lower frame 90
The distance between the inner walls of D is longer because the inner wall of the lower frame 90D is located lower than that of the mask 76.

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 the developing electrode 96
6 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 to form a developer/squeeze air inlet 100 and a developer/squeeze air outlet 102, respectively.

The developer/squeeze air inlet 100 is a passage 104 formed in the internal space of the process head 54.
It is communicated with. The passage 104 communicates with a developer supply port 106 and a squeezing air supply port 108 which are opened on the back side of the process head 54.
Further, the developer/squeeze air outlet 102 is a passage 1 formed in the internal space of the process head 54.
It is connected to 10. The passage 110 communicates with a developer/squeeze air 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 to form the squeeze suction port 1.
It is said to be 14. The squeeze suction port 114 is
As shown in FIG.
It communicates with a passageway 116 formed by an internal space. The passage 116 communicates with a suction squeeze opening 118 opened at the back side of the process head 54.

As shown in FIG. 11A, the developer supply port 106 is connected to the conduit 12 through a solenoid valve 120 in the middle.
It is connected to the developer tank 126 at 2,124. 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 . A developer pump 130 is disposed in a developer bottle 134.
The developer bottle 134 contains a developer 136 in which toner particles are dispersed in a solvent.

The pipe line 124 connecting the electromagnetic valve 120 and the developer tank 126 is branched in the middle to form a return pipe line 138 that opens into a developer bottle 134 . The developer tank 126 also includes a return pipe 140 that opens to the developer bottle 134.
are connected.

The squeeze air supply port 108 is connected to the conduit 142
It is connected to an air pump 144 for pressure squeezing. The developer/squeeze air outlet 11
2 is connected to a return conduit 146 that opens to the developer bottle 134.

As shown in FIG.
is connected to. Suction trap 150 is connected to conduit 1
At 52, it is connected to an air pump 154 for suction squeeze. Also, at the bottom of the suction trap 150 is a return pipe 15 that opens to the developer bottle 134.
6 are connected. The suction trap 150 has a return line 1 connected to the return line 156.
A valve 158 is provided which can close the solenoid 16 through a shaft 160.
It is designed to move up and down with 2.

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, which is tilted. .

(Drying Section) A frame wall 164 is formed in the drying section 68, as shown in FIGS. 5 and 6. Frame wall 16
4 is an upper frame 164A and left and right frames 164B, 164
C, and there is no lower frame. left frame 1
64B continues from the right end of the lower frame 90D of the mask 90, and rises from the front wall 74 together with the upper frame 164A. Also, right frame 164
C rises from a front wall recess 168 that is depressed from the front wall 74 in a stepped manner.

As shown in FIGS. 7 and 12, between the left and right frames 164B and 164C, the surface is a frame wall 164.
A wall 170 is formed slightly inward from the end surface, and recesses 172 are formed on both sides of this wall 170. The bottom surface of the recess 172 is
It is located at a position protruding from the wall surface of the front wall recess 178. These frame walls 164, walls 170 and recesses 172
The space surrounded by is a drying chamber 174. The inner width of the frame wall 164 is wider than the opening width of the mask 90. Further, 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 lower part of the upper frame 164A is opened to form a hot air outlet 176. As shown in FIG. 12, the hot air outlet 176 communicates with a passage 178 formed in the interior space of the process head 54. As shown in FIG. Passage 1
78 communicates with a hot air supply port 180 opened on the back side of the process head 54. A temperature sensor 182 is disposed in the passage 178. The hot air supply port 180 is connected to a heater 179 and an air pump 181 through a conduit 177.

(Fixing Section) As shown in FIGS. 5 to 7, the fixing section 70 is formed between the right 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 fitted into the frame portion 184, and a space in front of the glass plate 186 is used as a fixing chamber 188.

As shown in FIG. 13, a xenon lamp 192 and a reflecting plate 194 are disposed in a space 190 of the process head 54 formed on the back side of the glass plate 186. A cooling air outlet 196 is opened in the space 190, and cool air is supplied from an air pump 195 through 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, a blip sensor 196 is disposed at the left end of the front wall 74 of the process head 54. The blip sensor 196 is located at a height where the blip mark 24A of the electrophotographic film 24 being moved along the front surface of the process head 54 passes, and when the blip mark 24A passes, the blip sensor 196 is placed oppositely with the electrophotographic film 24 in between. It is designed to sense that the light from the light source for the sensor is interrupted.

(Film holding mechanism) As shown in FIGS. 7 and 14, a holding plate 19 is provided in front of the front wall 74 of the process head 54.
8 are arranged. The presser plate 198 has a 15th
As shown in the figure, a rectangular through hole 200 is formed which is slightly smaller in size than the opening shape of the mask 76 formed in the charging/exposure section 64.
The holding plate 198 is arranged so that the through hole 200 corresponds to the mask 76.

The presser plate 198 is shown in FIG.
5), claws 202 and 204 that protrude toward the process head 54 are formed at the upper and lower parts of the end on the side where the through hole 200 is formed. ing. nail 20
2, 204, the inner surfaces facing each other are inclined surfaces 2
02A, 204A, and as shown in FIG. 14, the upper and lower claws 202, 2 at the base
04 is made equal to the width of the electrophotographic film 24 (strictly speaking, slightly wider than the width of the electrophotographic film 24). A cylindrical portion 206 is formed protruding from the tip of the claw 204 . Claws 202, 204
is a hole 2 formed in the front wall 74 of the process head 54 shown in FIGS. 5, 6, and 14.
It is possible to fit into 08,210.

A cylindrical portion 212 is formed protruding from the rear surface of the holding plate 198 facing the process head 54, and a notch 214A formed at one end of an arm 214 is engaged with this cylindrical portion 212.
A retaining ring 212A is fixed to the tip of the cylindrical portion 212 to prevent the notch 214A from coming off. A boss portion 21 is provided at the other end of the arm 214.
4B is formed. The boss part 214B has a shaft 2.
16 is fixed.

The shaft 216 is connected to a stand 218 erected on the frame 60 to which the process head 54 is attached.
The frame 60 is rotatably inserted through and supported, and its lower end protrudes from the back surface of the frame 60 . A first 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 . Second lever 2
In the notch 226A formed at one end of 26,
The pin 222 is engaged. Second lever 2
The elongated hole 226B formed at the other end of 26 has a second
A tension coil spring 2 that biases the levers 226 in opposite directions and elastically supports the second lever 226.
One end of each of 28 and 230 is locked.

The other end of the tension coil spring 228 is attached to the frame 60
The other end of the tension coil spring 230 is fixed to a pin 232 vertically provided on the back surface of the frame 6.
Pull type solenoid 23 installed on the back side of 0
4 plunger 234A.

Holder plate 198 is spaced apart from process head 54 when 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 a hole 210 formed in the process head 54 and supported.

When the solenoid 234 is energized, the plunger 234A is actuated in the direction of arrow A, and the tension coil springs 228 and 230 are extended against the force.
As a result, the second lever 226 is rotated in the direction of arrow B around the shaft 224, and the first lever 220 is rotated in the direction of arrow C via the pin 222, thereby rotating the shaft 216 in the same direction. . The rotation of the shaft 216 causes the arm 214 to rotate in the direction of arrow D and press the presser plate 198 in the direction of arrow E.

The presser plate 198 is moved in the direction of arrow E with the cylindrical portion 206 guided by the hole 210 to press the electrophotographic film 24 into contact with the end faces of the masks 76, 90 and the frame wall 164. When the holding plate 198 is moved, if the position of the electrophotographic film 24 is misaligned in the height direction, the inclined surfaces 202A, 204A of the claws 202, 204 will move the electrophotographic film 24.
It acts to push down the upper edge of or push up the lower edge.

When the holding plate 198 presses the electrophotographic film 24 against the process head 54, the claws 202, 204 are fitted into the holes 208, 210, and the holding plate 198 is accurately positioned on the process head 54. Further, in this state, the holding plate 198 elastically presses the electrophotographic film 24 due to the action of the tension coil springs 228 and 230.

When the solenoid 234 is demagnetized, the second lever 226 is rotated in the direction opposite to arrow B by the tension coil spring 228, and the arm 214 is rotated in the direction opposite to arrow D.
The notch 214A is rotated in the direction of the retaining ring 212.
Press A to move the presser plate 198 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 apparatus is turned on, the cassette loading section 26 shown in FIG. 1 is raised, and a cassette containing electrophotographic film 24 can be loaded. After a 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 is movable 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 movement motor (not shown) is driven to move a predetermined frame freely selected from among the frames that have not yet been recorded. is located 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. controlled.

FIG. 16 shows a time chart when a predetermined frame is aligned and photographed as described above, and then consecutive photographs are taken for each frame following this frame. ing. In the process head 54, when the frame located in the charging/exposure section 64 is being charged and exposed, the developing section 66 and the drying section 6
8. Different processes are simultaneously performed on each frame located in the fixing unit 70,
The following explanation focuses on one frame in which the photographing button is pressed at the position shown in FIG. 16 and photographing is started.

To shoot the original 34, use the control keyboard 2.
The camera mode is selected and enabled by button operation 8. At the same time as this operation, the developing electrode 96 of the developing section 66 is energized and a bias voltage is applied, thereby heating the air blown into the drying chamber 174. The heater 179 is energized to generate heat, and the capacitor of the xenon lamp 192 of the fixing section 70 is energized and charged. These continue while the camera mode is selected.

When the shooting 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 to the adjacent electrode 80.
Corona discharge is generated between the mask electrode 82 and the mask electrode 82 . As a result, the surface of the photosensitive layer of the electrophotographic film 24 located within the opening frame of the mask 76 is electrically charged.

Note that when the shooting button is pressed, the solenoid 23 of the film holding mechanism continues from the previous process.
4 is energized, and the electrophotographic film 24 is pressed against the holding plate 198 and pressed against each end face of the masks 76 and 90 of the process head 54 and the frame wall 164. 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 6, the electrophotographic film 24 located on the end surface of the mask 76 is 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 regulated within the opening range of the mask 76.

In addition, since the mask electrode 8 provided in the charging/exposure chamber 72 is maintained at approximately the same potential as the charging potential of the electrophotographic film 24, the peripheral edge of one frame of the electrophotographic film 24 located in the opening of the mask 76 is The end portions are also charged to a potential close to the potential at the center of the frame, and the entire frame 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 applying a bias voltage to the mask electrode 82 from an external power source (not shown). By applying , the mask electrode 82 can be maintained at a potential approximately equal to the charged potential of the electrophotographic film 24 .

After the shooting button is pressed at the position, the document illumination lamp 36 is turned on after a predetermined period of time has elapsed, and the document platen 1
The original 34 placed on the glass plate 22 of No. 8 is irradiated. 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. The electrophotographic film 24 is charged by the corona discharge, but the mask 76
The notch formed in the end surface 76A allows the end surface 7
The effect of corona discharge does not reach the contact area with 6A and the vicinity thereof, and this area is not charged, but the area indicated by arrow W in FIG. 17C is charged.

At the same time as the corona wire 84 is de-energized, a shutter (not shown) (indicated by reference numeral A in FIG. 16) is opened, and the document is placed on the document table 18 by the optical system shown in FIG. The image light of the original document 34 is irradiated onto the electrophotographic film 24. Furthermore, at the same time, an automatic exposure control device (not shown) (indicated by reference numeral B in FIG. 16) starts integrating the amount of light.

Note that the electrophotographic film 24 is held by a presser plate 198.
Since it is pressed against the end surface of the mask 76, the focal length accuracy is ensured.

On the other hand, after a predetermined period of time has elapsed after the button is pressed, the motor 128 shown in FIG. 11A is driven and the operation of the developer pump 130 is started.
The developer 136 in the developer bottle 134 is pumped up into the developer tank 126. The developer 136 descends from the developer tank 126 under its own weight and flows into the pipe 124.
However, since the solenoid valve 120 is still closed at this time, the developer bottle 134 is discharged from the return line 138.
be returned to. Further, when the liquid level of the developer 136 rises in the developer tank 126, the developer 136
is returned to the developer bottle 134 from the return line 140.

In this way, the developer 136 is transferred to the solenoid valve 120.
Until the developer bottle 134 and the developer tank 126 are opened, the developer circulates between the developer bottle 134 and the developer tank 126 and remains on standby at a position immediately in front of the solenoid valve 120. This circulation stirs the developer 36 in the developer bottle 134.

When the integrated value of the light amount of the automatic exposure control device B reaches the set value, the integration is stopped, the shutter A is simultaneously closed, and the document illumination lamp 36 is turned off. At this point, the exposure process is completed, and one frame of the electrophotographic film 24, which is a charged part of the part located in the opening of the mask 76, is covered with the original 34.
An electrostatic latent image is formed by reducing the charge on the photosensitive layer according to the image pattern. Variations in the image density due to variations in the background density of the original 34, fluctuations in the voltage applied to the original illumination lamp 36, etc. are corrected by the automatic exposure control device B, so that proper exposure is always performed. Further, during this exposure, the electrophotographic film 24 has a charging portion that is connected to the mask 7.
6, black spot-like stains due to discharge will not occur.

At this time, if a predetermined period of time has elapsed since the button was pressed and all processing steps for other frames have been completed, the solenoid 2 of the film holding mechanism immediately
4 is demagnetized. When the solenoid 234 is demagnetized at the IA position in FIG. 16, the holding plate 198 is separated from the electrophotographic film 24. Even when the presser plate 198 is separated from the electrophotographic film 24, black spot-like stains due to electric discharge do not occur on the electrophotographic film 24 for the same reason as described above.

At the same time that the solenoid 234 of the film holding mechanism is deenergized, the solenoid 162 of the suction trap 150 shown in FIG. It is in communication with trap 150. As a result, the developer 136 that was captured in the suction trap 150 during the previous development/squeeze process (described later) is returned to the developer bottle 134.

After a predetermined period of time has elapsed after the solenoid 234 of the film holding mechanism has been demagnetized, a film moving motor (not shown) (indicated by C in FIG. 16) is driven, and the electrophotographic film 24 is moved toward the right in FIG. Pieces are moved. As a result, the charging/exposure section 6
The frame located at 4 is moved to the developing section 66. One frame movement of the electrophotographic film 24 is controlled by the blip sensor 196 detecting the blip mark 24A, as in the case described above.

After a predetermined period of time has elapsed after the film moving motor C is stopped, the solenoid 234 of the film holding mechanism is energized at position B in FIG.
is pressed against. At the same time, the solenoid 162 of the suction trap 150 is demagnetized and the return line 15
6 is occluded, air pump 15 for suction squeeze
4 is activated, and the solenoid valve 120 is further opened.

When the solenoid valve 120 is opened, the developer 136 passes through the conduit 122 to the process head 54 and enters the developer/squeeze air inlet 100 of the developing section 66.
and flows into the developing chamber 98 from there. The toner particles dispersed in the developer 136 are electrically charged, and as they flow down the developing chamber 98, the electrophotographic film 24
The electrostatic latent image is visualized by adhering to the charged parts of the body. Developer 136 flowing down the developing chamber 98
is from the developer/squeeze air outlet 102,
Developer bottle 134 passes through return line 146
be returned to.

Note that a part of the developer 136 supplied from the developer tank 126 to the pipe line 124 is returned to the return pipe line 1.
The pipe diameter of each pipe line is set so that the liquid is returned from the developer bottle 38 to the developer bottle 134 and the other liquid is directed to the electromagnetic valve 120.

The developer 136 flowing down the developing chamber 98 is pressed against the electrophotographic film 24 by a holding plate 198.
Since the mask 90 is pressed against the end face of the mask 90, it hardly enters the gap between the end face of the mask 90 and the electrophotographic film 24. From this part, the developer 136
If the water enters the left and right frame portions 90B of the mask 90, the suction squeeze air pump 154
Due to the negative pressure generated in the recesses 92 located on both sides of 90C, the developer 136 is squeezed into the squeeze suction port 1.
14 through conduit 148 to suction trap 150.
is sucked into and captured.

The developer pump 130 is deactivated by stopping the motor 128 after a predetermined period of time has elapsed after the solenoid 234 of the film holding mechanism is energized, but the solenoid valve 120 remains open even after that. There is. The developer 136 is in the developer tank 126
Since the developer 136 is supplied to the process head 54 by gravity, even if the operation of the developer pump 130 is stopped, the supply of the developer 136 to the developing chamber 98 is continued. In this way, even after the developer pump 130 is stopped, the supply of the developer 136 is continued, so that exposure blur due to vibration of the developer pump 130 can be minimized during exposure of the next frame. .

When the solenoid valve 120 is opened and a predetermined time has elapsed, the solenoid valve 120 is closed and the supply of the developer 136 to the developing chamber 98 is stopped. At the same time, an air pump 144 for pressure squeezing shown in FIG. 11A
is activated, developer/squeeze air inlet 1
Pressurized air is supplied from 00 to the developing chamber 98, and the developer 1 excessively attached to the electrophotographic film 24 is
36 is blown off and the liquid is drained. The blown-off developer 136 is returned to the developer bottle 134 from the developer/squeeze air outlet 102 through a return pipe 146.

Note that the supply of pressurized air to the developing chamber 98, that is, the blowing, is performed at a low level while a sufficient amount of the developer 136 remains in the developing chamber 98, so that the image is not affected by the high-speed blowing off of the developer 136. Deterioration is prevented. After a predetermined period of time has elapsed since the start of air blowing, the air is turned into strong air to increase squeezing efficiency.

The air blowing is controlled by the charging/exposure process for the next frame, which is started when the photographing button is pressed at the position shown in Fig. 16, and after the solenoid 234 of the film holding mechanism is demagnetized at the A position shown in Fig. 16, it continues for a predetermined period of time. After the elapse of time, the film moving motor C is started and stopped at the same time, and the developing/squeezing process is completed.

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.

When the drive of the film movement motor C is stopped,
The electrophotographic film 24 has been moved one frame to the right in FIG. 6, and the frame that was located in the developing section 66 is now located in the drying section 68. Film movement motor C
After a predetermined period of time has elapsed, the solenoid 234 of the film holding mechanism is energized at position B in FIG. 16, and at the same time, the air pump 181 shown in FIG. 12 is activated. When the air pump 181 operates, hot air heated by the heater 179 is blown out from the hot air outlet 176 of the drying section 68 to the drying chamber 174, and the developer 136 is dried. The operation of the air pump 181 is controlled by the frame charging/exposure process that is started when the photographing button is pressed at the position shown in FIG. 16, and the solenoid 234 of the film holding mechanism is demagnetized at the A position shown in FIG. At the same time, it is stopped and the drying process is completed.

Note that the temperature of the hot air supplied to the drying chamber 174 is detected by a temperature sensor 182.
If the temperature is out of a predetermined range, a message to that effect is displayed on the control keyboard 28, and if the temperature is out of the high temperature range, the power supply to the heater 179 is immediately stopped.

Furthermore, in the above example, the drying air pump 181 was activated only when the electrophotographic film 24 was being pressed against the process head 54 in conjunction with the solenoid 234 of the film holding mechanism. It may continue to operate at all times.

After the solenoid 234 of the film holding mechanism is demagnetized at position A in FIG. After the drive of the film moving motor C is stopped, the solenoid 234 of the film holding mechanism is energized at position B in FIG. 16, and at the same time, the air pump 19 shown in FIG.
5 is activated, cold air is supplied to the space 190 of the fixing section 70. This cold air passes from the space 190 through the upper part of the glass plate 186 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 19
2 is emitted, and the toner particles are transferred to the electrophotographic film 2.
4 and is fused and fixed, and the fixing process is completed.

Vaporized substances and scattered substances generated during fixing are blown off by the cold air supplied by the air pump 195, so that 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.

In the apparatus of this embodiment, after the frame located in the charging/exposure section 64, where the photographing button is pressed and photographing is started, is moved one frame to the developing section 66, the solenoid 234 of the film holding mechanism is energized. After a predetermined period of time has elapsed, the next frame can be photographed. From this time until after a predetermined period of time has elapsed after the air pump 144 for pressurizing the developing section 66 finishes blowing weak air, the shooting button is pressed to shoot the next consecutive frame. This is processed as continuous shooting, and by continuing this, the processing progresses as shown in FIG. 16.

Note that if the shooting button is not pressed within the above-mentioned period, or if the end of the series of shooting is input from the control keyboard 28, the timer stops the strong air blowing by the pressurized squeeze air pump 144. , subsequent drying and fixing are also processed by the timer.

The electrophotographic film 24 on which the original image is recorded as described above becomes capable of projection when the reader mode is selected. In the electrophotographic apparatus of this embodiment, the reader mode is automatically selected when a cassette is loaded by the same operation as described above (the third mirror 38 is moved from the position shown in FIG. 2 to another position). ), and by the same operation as described above, the predetermined frame is positioned and stopped in the charging/exposure section 64, and at the same time, the projection light source section 46 shown in FIG.
The light source is turned on, and this light passes through the electrophotographic film 24 through the through hole 200 of the presser plate 198,
The screen 16 is controlled by the optical system shown in FIG.
The image of the electrophotographic film 24 is enlarged and projected.

At the same time that the light source is turned on, the air pump 89 shown in FIG. 7 is activated to supply cold air to the charging/exposure chamber 72 to prevent the electrophotographic film 24 from becoming hot due to the heat from the projection light source section 46. This prevents defocusing due to thermal deformation.

In the reader mode, the electronic photographic film 24 can be read by pressing the buttons on the control keyboard 28.
The projected image can be viewed continuously in a short period of time by continuously advancing the image frame by frame. In this case, the shutter A is closed when the electrophotographic film 24 is moved, thereby preventing flickering due to an afterimage phenomenon.

When the copy button on the control keyboard 28 is pressed while the image is being projected onto the screen 16 as described above, the copy mode is selected and the copy mirror 52 is moved, and the optical system shown in FIG. The image projected on 16 is recorded on copy paper 30.

(Effects of Embodiment) As described above, in this embodiment, the inner corner of the end surface 76A of the mask 76 of the charging/exposure section 64 is cut out, and the mask opening is wide on the end surface 76A side. The contact area between the electrophotographic film 24 and the electrophotographic film 24 and its vicinity are not charged. For this reason,
Even if exposure is performed with the electrophotographic film 24 in contact with the mask 76, charge transfer due to discharge can be completely prevented, and focal length accuracy can be easily ensured.

Incidentally, in the above embodiment, the mask 76 was formed with a sloped notch, but as shown in FIG.
The inner surface of the end surface 76A of the mask 76 may have another shape, such as a stepped shape, and the opening on the end surface 76A side may be wide.

According to the applicant's experiments, the electrophotographic film 2
After ensuring the uniformity of the charging potential at the end of the charged region 4, the mask 76 of the electrophotographic film 24 is
It has been found that it is preferable to satisfy the following conditions in order to prevent the contact portion from being charged with electricity.

That is, first, from the opening position on the side of the corona discharge generating means which has the narrowest width, which is shown by the symbol S in FIGS. The opening depth (indicated by the symbol U in the figure) to the position shall be 0.5 mm or less.
Second, in FIG. 17C and FIG. 18, the symbol S,
The difference in opening length between both opening positions indicated by T (indicated by symbol V in the figure) shall be 0.2 mm or more. Thirdly, the distance indicated by the symbol U in FIGS. 17C and 18 is equal to or smaller than the distance indicated by the symbol V.

If the above three conditions are met and the shape of the mask has a wide opening on the front side, Figures 17 and 18
Even with shapes other than those shown in the figure, substantially the same good results as these can be obtained.

(Effects of the Invention) As explained above, in the process head for an electrophotographic apparatus according to the present invention, the opening of the mask of the charging section is wider on the mask surface side than on the corona discharge generating means side, and the opening of the mask is wider than the corona discharge generating means side. An area is formed around the outer periphery of the electrophotographic film where the effect of corona discharge does not reach, and the area of the electrophotographic film that contacts the mask opening end is not charged, so that black spot-like stains due to the discharge are not formed on the electrophotographic film. It has an effect that cannot be caused.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view showing an embodiment of the electrophotographic device, FIG. 2 is a perspective conceptual diagram showing the photographing optical system of the electrophotographic device, FIG. 3 is a perspective conceptual diagram showing the projection optical system, and FIG. 4 5 is an exploded perspective view of a process head according to an embodiment of the present invention installed in the electrophotographic apparatus of FIG. 1, FIG. 6 is a front view, and FIG. The figure is a view taken along the - line of FIG. 6, FIG. 8 is a view taken along the - line of FIG. 6, FIG. 9 is a view taken along the - line of FIG. An X-ray arrow view, FIG. 11 is an explanatory diagram showing the relationship between the process head developing section and other equipment,
Figure 12 is a - line arrow view of Figure 6;
The figures are a view taken along the - line in FIG. 6, FIG. 14 is a schematic side view showing the positional relationship between the process head and the holding plate, and FIG. 15 is a perspective view showing the film holding mechanism disposed in the process head. Figure 15A is the first
Perspective view of some parts of Figure 5 viewed from the opposite side, No. 16
The figure shows a time chart in the camera mode of an electrophotographic device, Figure 17A is an enlarged front view of the mask in the charging/exposure section, and Figure 17B is Figure 17A.
FIG. 17C is an enlarged detailed view of section C in FIG. 17B, and FIG. It is a sectional view showing an example. DESCRIPTION OF SYMBOLS 10... Electrophotographic apparatus body, 12... Copying device, 24... Electrophotographic film, 44... Main lens, 54... Process head, 62... Lens barrel, 6
4...Charging/exposure section, 66...Developing section, 68...
Drying section, 70...Fixing section, 72...Charging/exposure chamber, 76...Mask, 76A...End surface, 78...
Corona unit, 80... Proximity electrode, 82... Mask electrode, 84... Corona wire, 198... Presser plate.

Claims (1)

[Scope of Claims] 1. A mask made of an insulator, on the inside of which an opening is formed to limit the charging area of the electrophotographic film, and the electrophotographic film is brought into contact with the surface of the mask, and the mask is disposed facing the opening. In the process head for an electrophotographic apparatus, the aperture of the mask is wider on the mask surface side than on the corona discharge generation means side. A process head for electrophotographic equipment featuring: 2 The opening of the mask has an opening depth U from the opening position S on the corona discharge generating means side, which is the narrowest opening, to the opening position T on the surface, which is the opening on the corona discharge generating means side, which is the narrowest opening. 2. The process head for an electrophotographic apparatus according to claim 1, wherein the difference in aperture length between the position S and the aperture position T on the surface is equal to or smaller than the aperture length difference V. 3. The opening of the mask has an opening depth U of 0.5 mm or less from the opening position S on the side of the corona discharge generating means, which is the narrowest opening, to the opening position T on the surface, and 2. The process head for an electrophotographic apparatus according to claim 1, wherein the difference V in opening length between the opening position S on the side of the discharge generating means and the opening position T on the surface is 0.2 mm or more. 4. The process head for an electrophotographic apparatus according to claim 1, wherein the corona discharge generating means and the electrophotographic film are relatively stationary when the electrophotographic film is charged by the corona discharge generating means.