US3874328A

US3874328A - Developing device for electrophotography

Info

Publication number: US3874328A
Application number: US362253A
Authority: US
Inventors: Kenji Isonaka; Saburo Hokari; Tatsuya Watanabe; Masamichi Furukawa
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 1972-05-23
Filing date: 1973-05-21
Publication date: 1975-04-01
Anticipated expiration: 1992-04-01
Also published as: US3841750A; JPS4910050A; JPS5335729B2; US3934256A

Abstract

A developing roller has axially spaced flanges and is partly immersed in developing liquid. A cord material bearing an electrostatic latent image is moved along a path tangent to the periphery of the flanges of the developing roller, with the latent image bearing surface facing the developing roller. The image bearing portion of the card material is narrower than the axial distance between the flanges of the developing roller, such that the image bearing portion of the card material is spaced from the facing circumference of the developing roller. The roller is rotated at a different peripheral speed than the speed of the card material, but streaking of the developed image does not occur because the image bearing portion of the card material is not contacted directly by the developing roller. The card material moving toward the developing roller is tilted such that either its leading end is higher than its trailing end or vice versa depending on the direction of rotation of the developing roller so as to prevent developing liquid from reaching the side of the card material which faces away from the developing roller. After developing, the image bearing side of the card material is pressed against a blotter roller whose outer circumference is greater than the length of the image bearing portion of the card material in order to prevent the occurrence of an offset phenomenon.

Description

United States Patent Isonaka et al.

[i 3,874,328 [451 Apr. 1, 1975 DEVELOPING DEVICE FOR ELECTROPHOTOGRAPHY [75] Inventors: Kenji Isonaka, Tokorozawa; Saburo Hokari, Kawasaki; Tatsuya Watanabe, Yokohama; Masamichi Furukawa, Kawasaki, all of Japan [73] Assignee: Ricoh Co., Ltd., Tokyo, Japan [22] Filed: May 21, 1973 [21] Appl. No.: 362,253

[30] Foreign Application Priority Data May 23, 1972 Japan 47-51010 [52] US. Cl ..118/l16,1l8/212,118/236 [51] Int. Cl. B056 1/02 [58] Field of Search 118/637, DIG. 23, 244, 118/212, 102, 116, 117, 236; 354/318 [56] References Cited UNITED STATES PATENTS 1.987.387 l/l935 Conklin 354/318 3.104603 9/1963 Szhwienbacher 354/318 Primary E.\'aminer-John P. Mclntosh Attorney, Agent, or Firm-Cooper, Dunham, Clark, Griffin & Moran [57] ABSTRACT A developing roller has axially spaced flanges and is partly immersed in developing liquid. A cord material bearing an electrostatic latent image is moved along a path tangent to the periphery of the flanges of the developing roller, with the latent image bearing surface facing the developing roller. The image bearing portion of the card material is narrower than the axial distance between the flanges of the developing roller, such that the image bearing portion of the card material is spaced from the facing circumference of the developing roller. The roller is rotated at a different peripheral speed than the speed of the card material, but streaking of the developed image does not occur because the image bearing portion of the card material is not contacted directly by the developing roller. The card material moving toward the developing roller is tilted such that either its leading end is higher than its trailing end or vice versa depending on the direction of rotation of the developing roller so as to prevent developing liquid from reaching the side of the card material which faces away from the developing roller. After developing, the image bearing side of the card material is pressed against a blotter roller whose outer circumference is greater than the length of the image bearing portion of the card material in order to prevent the occurrence of an offset phenomenon.

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1 l l l I I I l SWIO SW7 SW5 PATENTE APR n97 SWI DEVELOPING DEVICE FoR ELECTROPHOTOGRAPHY BACKGROUND OF THE INVENTION The invention relates to developing devices used in electrophotography.

In electrophotography using wet developing agents, a developing liquid is prepared by dispersing minute powder of carbon black or other pigment treated with a resin or toner particles in petroleum or other carriers of high electrical resistance. The developing liquid is kept in a container and a rotating developing roller is partly immersed in that developing liquid. A sheet bearing an electrostatic latent image is moved along a path tangential to the periphery of the developing roller to thereby apply developing liquid to the latent image and to develop it into a visible image. Some disadvantages are associated with this type of a developing device. One is that the developing agent tends to reach the side of the sheet which faces away from the developing roller to thereby stain that side and detract from its appearance. Another is that the difference between the speed of the sheet and the peripheral speed of the rotating developing roller sometimes causes streaks in the image.

In wet developing devices of this type it is usually necessary to provide a blotter roller for drying the developed side of the sheet. No particular attention has been paid in the past to the size of the blotter roller and the so-called offset phenomenon" has occured on oceasion because of the blotter roller.

SUMMARY OF THE INVENTION The invention is in the field of developing devices for eleetrophotography.

An object of the invention is to provide a device using wet developing agent which obviates the disadvantages of the prior art devices of this type discussed above. The invention is embodied in a developing device including a developing roller having axially spaced flanges that prevent direct contact between the portion of a card material which carries an electrostatic latent image and the circumference of the developing roller to thereby prevent streaking of the developed image even when there is a great difference between the speed of movement of the card material and the peripheral speed of the rotating developing roller. The developing device according to the invention also includes provisions for tilting the card material as its leading edge approaches the developing roller so as to prevent developing liquid from reaching the side of the card material that faces away from the developing roller and to apply developing liquid only to the latent image bearing portion of the card material. Depending on the direction of rotation of the developing roller. the tilting may be such that the trailing end of the card material is moved radially away from the developing roller. The developing device according to the invention also includes a blotter roller constructed and operating such that it prevents the occurrence of the so-ealled offset phenomenon".

Specifically. the circumference of the blotter roller is made at least as long as the length ofthe image bearing portion of the card material. and is preferably equal to the length of the entire card material.

A hold-down roller and a squeezing roller of specific construction and dimensions may be provided downstream of the developing roller.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a sectional view of an identification card produced by an apparatus in which the invention is incorporated. I

FIGS. 2 through 9 are explanatory views of the steps of a method of producing identification cards in which this invention may be used.

FIG. 10 is a perspective of an identification card producing apparatus in which the invention is incorporated.

FIG. 11 is a plan view of the internal structure of the apparatus shown in FIG. 10.

FIG. 12 is a schematic view of the internal structure of the apparatus of FIG. 10 as seen from below.

FIG. 13 is a schematic view showing a card material passage of the apparatus of FIG. 10.

FIG. 14 is a plan view showing a charging device, a screen and a projection lens in relation to a photore ccptor. all forming a part of the apparatus of FIG. 10.

FIG. 15 is a perspective view of a screen ruled with a fine mesh of cross lines.

FIG. I6 is a sectional view of the screen shown in FIG. 15.

FIGS. 17 through 19 are sectional views showing the charging device and the screen in relation to the photoreceptor.

FIG. 20 is a schematic view of a photographing position of the photoreceptor and a transfer printing position thereof.

FIG. 21 is side view of a return means for positioning a card material.

FIGS. 22 and 23 are plan views showing'the electrical grounding of a card material.

FIG. 24 is a sectional view of a card material and of a grounding knife.

FIGS. 25 through 27 are sectional views of a transfer printing device.

FIGS. 28 is a schematic view showing the range of movement of a transfer-printing roller.

FIG. 29 is a perspective view of the transfer printing roller.

FIGS. 30 and 3] are perspective views showing the photoreceptor mounted on a backing plate.

FIGS. 32 through 39 are side views showing means for tensioning the photoreceptor mounted on the backing plate.

FIGS. 40 is a sectional view illustrating a developing device using a wet developing agent and comprising one embodiment of the invention.

FIGS. 4] through 47 are schemmatie views of portions of the developing device shown in FIG. 40.

FIG. 48 is a circuit diagram of control means for the identification card producing apparatus in which the invention is incorporated.

DETAILED DESCRIPTION An identification card prepared in accordance with the subject invention is illustrated in FIG. I and comprises a supporter l. a conductive material layer 2 deposited over the supporter l, and a dielectric layer 3 deposited over the conductive material layer 2. A toner image 4, which may be the photographic image of a person, is on the dielectric layer 3. and markings 5.

which may be printed or handwritten matter, stamps and the like are also on the dielectric layer 3. A transparent protective layer 6 is deposited over the dielectric layer 3 to protect the toner image 4 and the markings 5 thereon.

The supporter 1 may be a relatively thick sheet of paper or of a synthetic resinous material and its stiffness may be further increased by applying a backing material to it. The conductive material layer 2 mmay be deposited on the supporter l by vapor deposition of aluminum in vacuum, or by other suitable means. The dielectric material layer 3 may be of a material such as an acrylic resin, mcthacrylic resin, vinyl chloride or the like, and may be deposited on the conductive material layer 2 by the use of a binder. The dielectric material layer 3 may be formed by using a binder including a photoconductive material, such as zinc oxide, polyvinyl carbazol or the like. If a sheet of a suitable metal or of rubber is used as the supporter l, the conductive material layer 2 may be eliminated. The toner image 4 may -be formed by first forming an electrostatic latent image of a person and then developing the latent image such as by powedered toner particles. The markings 5 may be entered by printing, stamping or handwriting or by any other suitable means. The transparent material layer may be formed by applying a film of vinyl chloride or other synthetic resinous material, or by applying a solution of a synthetic resinous material used as a laminating material, or by immersing the card in such solution.

It is noted that an identification card of the type described above does not rely on silver salt photography and can therefore be produced without the cumbersome steps involved in producing a photographic print. Further, the prior art need to paste a silver salt photographic print onto an identification card, to affix a seal to the card material or to make another type of an impression on the photographic print and on the card material is eliminated, because the entry of markings necessary for identifying the card user may be made directly on the surface of the photographic image either by handwriting, printing, stamping, or the like.

Stillfurther, the toner image formed in accordance with the invention is not subject to fading. The toner image formed on an identification card in accordance with the invention has a sufficient range of half tones, and it is neither'too sharp in contrast or too poor in contrast as sometimes happens with ordinary photographic images. The toner image is of high quality and is effective to identify the card user.

The inventionn may be explained in a simplified manner by reference to the seven basic steps discussed in connection with FIGS. 2 through 9. These steps are as follows: I

Step 1 (FIG. 2). A photoreceptor 23 comprises a photoconductive material layer 22 deposited on a supporter 2] which is electrically conductive. The supporter 21 may be made of material such as aluminum,

copper or other electrically conductive materials, and

. the photoconductive material layer 22 may be vapor deposited in vacuum and may comprise materials such voltage power source CI and moved in the direction of an arrow a.

A high bias voltage of a polarity consistent with the charge characteristics of the photoconductive material layer 22 is impressed on the wire electrode C2 in order to suitably charge the layer 22. For example, if the layer 22 comprises selenium, the bias voltage would be positive. A bias voltage of the opposite polarity is impressed on the supporter 21, or the supporter 21 may be grounded as shown. The supporter 21 may be backed or framed by a suitable insulating plate (not shown).

Step 2 (FIG. 3). A screen 24 is disposed immediately adjacent the photoconductive' material layer 22 after the layer 22 is uniformly charged throughout its entire surface. The screen 24 may be a fine mesh screen of a material such as insulated synthetic resinous material sheet formed with a plurality of very small openings by a process such as photo-etching. Alternately, the screen 24 may he a glass sheet ruled with a fine grid of cross lines. The purpose of the screen 24 is to produce a mesh point effect in the image which is projected onto the photoconductive material layer 22 in the next step 3. The size of the opening of the mesh screen 24 is selected to produce dots which are beyond the resolving power of the human eye at a normal reading distance.

Step 3 (FIG. 4). The photoconductive material layer 22 is exposed to an optical image of a person 26 through a projection lens 25. The fine mesh screen 24 is between the photoconductive layer 22 and the projection lens 25. A diaphragm 27 is opened for a suitable period, such as l/30th of a second. The sensitivity of the photoconductive material layer 22 may be increased by using a coloring matter or other sensitivity increasing agent. The spacing between the fine mesh screen 24 and the photoconductive material layer 22 is selected such that the screen mesh can be photographed on the surface of the photoconductive material layer 22 by the projection lens 25. It should be clear that a photographic latent image on the layer 23 may be formed by photographing either a person 26, or a photograph or another image thereof, or by photographing another object.

Step 4 (FIG. 5). After a latent image is formed on the layer 23 in step 4, a sheet of card material 28 is brought in contact with the photoreceptor 23 such that the dielectric material layer 29 of the card material 28 faces the latent image bearing photoconductive material layer 22 of the photoreceptor 23. The photoelectric latent immage is transferred to the dielectric material layer 29 of the card material 28 by transfer printing. The card material 28 is identical with the card material discussed in connection with FIG. 1, except that it does not have the transparent layer 6 or the markings 5 or the toner'image 4 of the card material shown in FIG. 1. Transfer printing of the type shown in FIG. 5 can be carried out by pressing the photoreceptor 23 and the card material 28 against each other with sufficient force, such as by a suitable roller arrangement. The conductive material layer 31 of the card material 28 may be electrically grounded, or a bias voltage ofa suitable polarity and level may be impressed on the conductive material layer 3 I as is conventional in transferprinting.

Step 5 (FIGS. 6 and 7). After step 4, the card material 28 bears an electrostatic latent image. The purpose of step 5 is to develop this latent image into a visible image. This may be done by suitable developing means such as the means illustrated schematically in FIG. 6 where the card material. 28 is conveyed by suitable conveyor means (not shown) in the direction of an arrow l2 and the dielectric material layer 29 thereof is brought in contact with the periphery of a developing roller 34 which is partly immersed in a developing liquid 33 in a container 32. The developing roller 34 may be a conductive metallic roller made of materials such as copper or aluminum, or may be a conductive rubber roller. The developing liquid 33 includes fine toner particles which are supplied to the electrostatic latent image to convert it into a visible toner image 35. Any other suitable device for developing electrostatic latent images may be used. The toner contained in the developing agent may comprise fine powder of carbon black or other pigment treated with a resin.

Step 6 (FIG. 8). Markings such as the signature and identification number, and other particulars of the card user may be entered on the same surface of the card material28 which bears the developed visible image 35. The markings may be entered by handwriting, typing. printing, stamping or the like.

Step 7 (FIG. 9). A transparent protective film 6:! is

laminated onto the surface of the card material 28 which bears the visible image and the markings. Thhe lamination is carried out with the help of

laminating rollers

36a and 36b in a conventional manner. After lamination, the identification card according to the invention is ready for use. If should be clear that instead of laminating. the card material may be protected by other suitable means, such as by synthetic resinous material in liquid form applied to the card material surface, or the card material may be immpregnated with such liquid.

The seven steps discussed above are only a brief and simplified explanation of some of the major steps involved in practicing the invention. A specific device emboying the invention is described below.

Referring to FIGMIO. an identification card producing devide according to the invention comprises a casing 41 which has a front side with a taking lens 42 and a finder objective window 43. The top side ofthe casing 41 has a finger window 44. push-button 45 for a main off-on switch SW] and a push-button 46 for a shutter release switch SW2. The push-botton 45 has a built-in lamp LI to indicate that the device is on. and the pushputton ,46has a built-in lamp L2 to indicate that the shuter release is operable as subsequently described in connection with FIG. 49.

Referring to FIG. 10 again. a cutout 48 is formed in the upper portion of the card material feed port 47 at the left side of the device 4I. A card material 49 (see FIG. ll) may he inserted in the port 47 and is pushed rightwardly to aposition in which its trailing end is substantially aligned with an innermost edge 48:: of the cutout 48 (FIG. II). The card material 49 is identical with the card material 28 discussed above.

Referring to FIG. l3. support plates SI and 55 are disposed inwardly of the card material feed port 47 of the casing 4i. The support plate 5] has a support bar 50 mounted on one marginal portion thereof to define a guide recess 51a. and the support plate has a cutout 52 and a support bar 54 to define an outer guide recess 55a. The two

guide plates

51 and 55 are disposed such that the card material 49 inserted through the port 47 moves in the direction of an arrow with the side margins of the card material 49 received within the guide recesses 51a and 55a. The vertical dimension of the guide recesses 51:! and 55a is such that the card material 49 can be maintained in a horizontal position as the card moves in the direction of the arrow 0. Referring still to FIG. 13, positioning member 56 is disposed at the right forward side of the card material feed port 47. The positioning member 56 has an inwardly inclined edge 56a to guide the right front shoulder 49:! of the card material 49 as it is inserted into the port 47. The positioning member 56 is secured to one end of a bar 57 which has slots 57a and 5712 and is slidably supported on the support 51 by a pin 58 extending from the support plate 51 and loosely received in the slot 580. A screw 59 is threaded into the support plate 51 and is loosely received in the slot 57b of the bar 58. The bar 57 has at its right-hand end an upwardly bent portion 570, and a spring 60 connects the upwardly bent portion 571' and the pin 58 to urge the bar 57 leftwardly.

When the card material 49 is inserted through the port 47 into the casing l. the right front shoulder 49a thereof pushes the positioning member 56 out of the card material passage against the biasing force of the spring 60. As the card material 49 is pushed further into the casing 60, the left edge ofthe positioning member 56 is maintained in engagement with the right-hand side ofthe card material 49. However, when the trailing end of the card material 49 has passed through this portion of the passage, the positioning member 56 is moved leftwardly by the spring 60, such that its lefthand portion 56b is again disposed in the passage of the card material (FIG. 11).

The positioning member 56 has a major edge 560 which engages the trailing end of the card material 49 to correctly position the card material when it is pushed backwardly by a card material push-back pawl 61 after it has been pushed in to the casing 41. This position of the card material 49 is shown in FIG. I1. As described in detail below, the position of the card material 49 whown in FIG. 11 is the transfer printing position in which the card material 49 and a photoreceptor 62 (FIG. 12) are pressed against each other so that an electrostatic latent image which is at this time on the photoreceptor 62 is transferred. onto the card material 49. The photoreceptor 62 is identical in construction with the photoreceptor 23 discussed in connection with FIGS. 2 through 5.

The photoreceptor 62, and several ways of mounting the photoreceptor 62 onto a backing plate 63 (which corresponds to the backing plate 21 of FIGS. 2 through 5) are shown in detail in FIGS. 30 through 39.

Referring to FIGS. 30 and 31., the photoreceptor 62 is shown as a relatively thin sheet and the backing plate 63 is shown as a relatively thick plate having a U- shapcd groove 63a at its back edge. The photorecptor 62 is sufficiently long so that its front and back ends can fold over the front and back ends respectively of the backing plate 63.

The photoreceptor 62 is used to form thereon an electrostatic latent image and then to transfer this electrostatic latent image onto the card material 49 by transfer printing. A transfer printing operation of this type is illustrated schematically in FIG. 32. and it can be seen that it is desirable that the photoreceptor 62 be tightly stretched over the backing plate 63 in order to avoid distortions of the transferred image. As seen in FIG. 32, if the top portion of the photoreceptor 62 is not properly tensioned over the backing plate 63, wrinkles and other distortions may form as a transfer printing roller 69 is moved in the indicated direction.

Several suitable arrangements for tensioning the photoreceptor 62 over the backing plate 63 are shown in FIGS. 31 and 33 through 39. Referring to FIG. 31, a pair of mounting members 64 and 65 are secured to the sides of the backing plate 63 which flank the grooves 63a. A round bar 66 is inserted in the groove 630, over the folded end of the photoreceptor 62, and screws 67 and 68 are inserted through suitable openings in the round bar 66 and are threaded into suitable threaded openings 64:: and 650 respectively of the mounting members 64 and 65 to fasten the round bar 66 to the backing plate 63 and to thereby tension the photoreceptor 62.

Referring to FIG. 33, the photoreceptor 62 may be secured to the backing plate 63 by suitable screws fastening the folded over ends of the photoreceptor 62 to the underside of the backing plate 63. Alternately, the folded over ends of the photoreceptor 62 may be adhesively bonded to the underside of the backing plate 63.

When the photoreceptor 62 is secured to the backing plate 63 as shown in FIG. 33, the photoreceptor 62 may be tensioned by a keep bar 71 disposed as shown in FIG. 34. The function of the keep bar 71 is similar to thatof the round bar 66 shown in FIG. 31. An alternate way of tensioning the photoreceptor 62 is shown in FIGS. 35 and 36 and involves the use of a resilient stopper plate 72 having stopper ends 7211 and 72b. The stopper plate 72 is attached to the underside of the backing plate 63 and the end stoppers 72a and 72h thereof are inserted in grooves 63a and 63h respectively of the backing plate 63 over the folded ends of the photoreceptor 62. An alternate type of a stopper plate is shown in FIGS. 37 and 38 where a stopper plate 73 has a single stopper end 73:! which cooperates with a groove 63a in the backing plate 63.

A still alternate manner of tensioning the photoreceptor 62 over the backing plate 63 is illustrated in FIG. 39 and involves the use of a stopper plate 63 having offset portions 76a and 76h at its front and back ends respectively. After the front and back ends of the photoreceptor 62 are secured to the front and back sides of the backing plate 63 respectively by suitable screws or otherwise, keep bars 77 and 78 are placed on the offset portions 761: and 76h respectively, over the front and back ends of the photoreceptor 62 respectively. and are fastened to the backing plate 63 by suitable screws 79 and 80 to tension the photoreceptor 62.

Referring to FIG. 12, a photoreceptor 62 mounted on a backing plate 63 in one of the several possible ways discussed above is mounted on a photoreceptor support plate 81. The plate 81 has arms 81a and 81h that are loosely supported by a shaft 82 disposed on the right side of the card material passage and parallel thereto, so that the photoreceptor 62 is maintained in the photographic position shown in FIG. 12.

Arm means 83 are disposed to the right of the arm 81/2 and are firmly secured to the shaft 82 at a tubular portion 84 thereof. The arm means 83 are bent substantially in the middle so that the front end 8311 thereof may be disposed beneath the arm 81h. A coil spring 85 urges the arm 81h toward a pressing engagement with the foreward end 83a of the arm means 83.

LII

The shaft 82 is rotatably supported by fixed

supporters

86 and 87, and a cam 88 having an arcuate major diameter portion 880 is secured to a portion of the shaft 82. on the side ofthe supporter 87. by a boss 89 thereof which is fitted over the shaft 82. The shaft 82 is urged to rotate in the direction of the arrow 0 by the biasing force of a coil spring 90.

The supporter 81 is maintained in engagement with a plate shaped stopper 91 as the shaft 82 tends to rotate in the direction of the arrow 0 under the biasing force of the spring 90. The stopper 91 is positioned by a positioning member 9141 so that the photoreceptor 62 can be correctly positioned at its photographing position relative to the taking lens 42.

Two

rails

93 and 94 are parallel to each other and to the surface of the photoreceptor 62 and are disposed in front of and below the photoreceptor 62. The

rails

93 and 94 have bosses a, 95b, 96a, and 96b which are fitted over two charging device support bars 95 and 96 respectively to thereby mount the

bars

95 and 96 slidably on the

rails

93 and 94 respectively.

The

rails

93 and 94 of FIG. 12 support a charging device 97 which is illustrated in FIG. 14. Referring to FIG. 14. the charging device 97 includes a frame 98 affixed to the charging device support bars 95 and 96 and including

wire electrodes

99 and 100 separated from each other by a partition 98a. A high bias voltage of a suitable polarity is impressed on the

wire electrodes

99 and 100 by a suitable high voltage source Ch (FIG. 49) in the course of the charging step described below.

Referring back to FIG. 12, the charging device support bar 96 has at its center a projection 96c supporting one end of a wire 102 which is wound on a pulley 101. The pulley 101 is adapted to be connected through a gear 103, affixed to a shaft 10111, to a drive mechanism 104 connected to a motor M1 (FIG. 49). Referring to FIG. 49, upon the energization of a solenoid SOLI after the shutter release SW2 is closed and a charging initiation command is issued, the gear 103 and the pulley 101 are connected to the drive mechanism 104 to start rotating in the direction of an arrow f.

Referring to FIG. 12, the charging device 97 is originally at its initial position leftwardly of the photographing positionn shown in the figure while in the initial position, the charging device support bar 95 keeps a switch SW3 in a depressed position. As the pulley I01 starts rotating in the direction of the arrowf, the charging device 97 is pulled by the wire I02 and passes by the front of the photoreceptor 62. At the same time, the switch SW3 is released from the depressed position and actuates the high voltage source Ch (FIG. 49), which impresses a suitable voltage on the

wire electrodes

99 and 100 to thereby charge the entire surface of the photoconductive material layer of the photoreceptor 62 by a corona discharge. The motion of the charging device 97 is illustrated in FIG. 14.

Referring back to FIG. 12, a pin 98b is secured to the underside of the frame 98 of the charging device 97. A lever 105 has a front end which is disposed to the right of the pin 98b and is pivotally supported at its base by a shaft 106. The lever 105 is normally urged by the biasing force of a spring 107 to move clockwise. A shutter charging arm 1090 is integral with a ring 109 mounted on a tube 108 of the projection lens 42. The arm 109a is disposed to the right ofthe base ofthe lever 105. The ring 109 has a pressing arm I09!) designed to engage a set lever 110 for a shutter (not shown). When the charging device 97 moves from its initial position as described below. the shutter charging arm 109a is pushed and moved through the pin 98d and the lever 105. This rotates the ring 109 in the direction of the shown arrow such that the pressing arm 109/2 engages the projection 110a of the set lever 110 to thereby charge the shutter. It should be clear that other suitable shutter charging means may be employed. For example, a shutter of the type that is normally set may be employed and may be charged by a suitable motor actuated upon a suitable operation command.

A command to energize the solenoid SOLl to move the charging device 97 from its initial position and to actuate the high voltage source Ch to start a corona discharge may be issued by a switch SW disposed below the passage of the card material 49 and having an actuator 92 adapted to be depressed by the card material 49 as it moves along its passage after being inserted in the card feed port 47 (FIG. The switch SW0 may be disposed at any other suitable position, and may be replaced by suitable card material sensing means (not shown) using a photoelectric transducer element or the like. Altcrnately. the solenoid SOL] may be actuated in response to the closing of the main switch SW1.

Referring to FIG. 12 again, the charging device support bar 95 extends to the right and has a bent end portion 950 adapted to depress a projection 11a formed in a plate shaped actuator III of a double throw switch SW41.2 when the charging device 97 moves from its initial position. The actuator 111 has slots 11111 and I 1 11 which receive

support shafts

112 and 113 respectively for moving the actuator 111 in sliding motion in the same direction as the end portion 950 of the support bar 95. The actuator 111 is urged by the biasing force of a spring 114 to move away from the double throw switch SW4-l,2. When the bent end portion 95(- of the support bar 95 depresses the projection 11111, the actuator 111 moves toward the double throw switch SW41.2 against the biasing force of a spring 114 to depress the switch SW41,2.

The double throw switch SW4I,2 includes a switch SW4-l whose function is to deenergize the solenoid SOLI which actuates the gear 103 and the pulley 101. Thus. when the switch SW4-1 is closed, the charging device 97 starts returning to its initial position. When a lock lever 115 is brought into engagement with a cutout 11111 formed in the actuator 111, the actuator 111 is locked in a position for holding the double throw switch SW4-l.2 in its depressed position. It should be understood that the double throw switch SW4I,2 may he held in its depressed position by a self-holding circuit using a suitable relay (not shown). and that the charging device 97 may be returned to its initial position by eliminating the switch SW41 and using a timer (not shown) which is adapted to deencrgize the solenoid $01.1 after a predetermined time delay following closing of the main switch SW1. The lock lever 115 is pivotally supported by a shaft 1 /1 and is urged by the biasing force of a spring 1150 to move into engagement with the cutout 1111/ formed in the actuator 111 as described above.

Referring to the left-hand portion of FIG. 12., a projection 105a extends upwardly from the central portion of the arm 105. A member 116 is loosely mounted on a shaft 118 that is loosely received through an end por tion of an arm 117. The member 116 extends in the path of the pivotal movement of the projection 105.

Referring to FIG. 21 for a clearer illustration, the shaft 118 is rotatably supported by a fixed supporter 119 and has thereon a spring 120 which is also secured to the member 116 and the arm 117. The member 116 has a portion 116:: adapted to be engaged by the arm 117 to permit the arm 117 to act as a single unit with the member 116. The arm 117 is pivotally connected at its other end to a lower portion ofa connector 121 that pivotally supports at its upper portion a push-back pawl 61 for pushing back the hard material 49 at the appropriate time. the pawl 61 is pivotally supported at its base through a shaft 125 by a supporter 124 affixed to the underside of a support plate 51.

When the arm 105 moves in the direction of an arrow g, in association with the movement of the charging device 97 from its initial positiion, the member 116 is pressed in the same direction by the projection 105 in the terminating stage of the movement of the arm 105. When pressed, the member 116 moves clockwise about the shaft 118. and the arm 117 also moves with the member 116 as a unit by virtue of the biasing force of a spring 120. The movement of the arm 1 17 is transmitted through the connector 121 to the pawl 61 which is moved from its position shown in solid line in FIG. 21 to the position shown in its dash and dot line in the same figure The pawl 61 push-es th card material 49 backwardly and moves it until it engages the edge 56(' ofthe positioning member 56. The force with which the arm 105 pushes the member 116 after the pawl 61 has pushed the card material 49 backwardly is absorbed by the spring 120.

When the charging device 97 begins to return to its initial position. the arm 105 is also restored to its original position, thereby releasing the member. 116 from the pressure applied thereto. When a member 116 is released, the member 116, the arm 117, the connector 121 and the pawl 61 are all restored to their original positions by the biasing force of a spring 126 mounted between the portion 1161! of the member 116 and a fixed member 125. When the solenoid SOL] is decnergized and the gear 103 and the pulley 101 are rendered inoperative. the charging device 97 is pulled back to its initial position through the pin 98b and the arm 105 by the biasing force ofthe spring 107 mounted on the arm 105. At the same time the support bar 95 depresses the switch SW2. so that the charging voltage is no longer present.

Referring back to FIG. 12, a screen support arm 128 is secured at its base to an upper end portion of a shaft 127 which is rotatable disposed to the left of the photoreceptor 62 which is at its photographing position. Secured to the support arm 128 is a screen formed with a mesh 129 (FIGS. 15 and 16). The screen 130 is supported by a downwardly bent front end portion 128a of the arm 1.28 and by a stay 131 (FIG. 12). The screen 130 is identical in construction with the screen 24 discussed in connection with FIGS. 3 and 4 and has a margin defining frame 132 made of an electrically conducting material such as metal foil. In FIG. 12, an arm 137 having a pm 133 secured to its front end portion is pivotally supported at its base by the lower end portion of a shaft 127. A lock member 135 is secured to the shaft 127 and is disposed below the arm 134. Mounted on the shaft 127 and disposed between the lock 135 and the arm 134 is a spring 136 which urges the arm 134 to move in the counterclockwise direction in FIG. 11 and to cause the pin 133 to engage one end of alever 137 from the right in FIG. 11. The lever 137 is pivotally supported by a shaft 138 and is loosely connected at the other end through a shaft 138 to a connector 140 that is in turn pivotally connected to an actuator 139 of a solenoid SOL2.-

The actuator 139 of the solenoid SOL2 is in an extended position when the solenoid is decnergized. When the actuator 139 is in this extended position, a connector 140 depresses a switch SW5 as shown in FIG. 12. When the switch SW4-2 which forms a part of the double throw switch SW41,2 is depressed, and the switch SW3 is depressed by the charging device 97 restored to its initial position, a command to energize the solenoid SOL2 is issued and the actuator 139 is withdrawn into the solenoid. This causes the lever 137 to move clockwise in FIG. 11, with the arm 134 pivotting and the shaft 127 rotating in slaved relation to the lever 137 under the biasing force of a spring 136.

The rotation of the shaft 127 moves the screen support arm 128 and the screen 130 in the direction of an arrow Ii shownin FIG. 14, so that the margin defining frame 132 is brought into engagement with the margins of the photoreceptor 62 which has just been charged. When the solenoid SOL2 is energized, the switch SW5 is opened. Opening of the switch SW5 does not affect any of the elements shown in the figure.

After the procedure described above, the photoreceptor 62 is charged, as shown in FIG. 17, by the charging device 97. When the margin defining frame 132 is brought into engagement with the photoreceptor 62, as shown in FIG. 18, an optimum spacing is maintained between the photoreceptor 62 and the screen 130. Because of the frame 132, the charge carried by the margin of the photoreceptor 62 is removed, as shown in FIG. 19, to thereby prevent adhesion of toner particles to the marginal area of the photoreceptor 62 and to prevent such toner particles from smearing or otherwise detracting from the appearance of the identification card produced later. The margin defining frame 132 of the screen 130 may be electrically grounded by suitable means. or a suitable bias voltage can be impressed on it. Alternately, the electrical charge on the margin ofthe photoreceptor 62 may be removed by increasing the electrical capacity of the margin defining frame 132.

Referring back to FIG. 12, when the screen 130 is pressed against the photoreceptor 62 that is at the photographing position shown in solid lines in the figure, an optical image of a person or of an object may be projected onto the photoreceptor 62 through the lens 42. A command to release the shutter of the lens 42 is issued, and at the same time a stobe light STL (FIG. 49) is actuated to illuminate the picture or object which is being projected. The optical image formed by the lens 42 is projected onto the photoreceptor 62 through the screen 130, as shown more clearly in FIG. 20. The optical image projected onto the photoreceptor 62 forms an electrostatic latent image thereon. The shutter release switch SW2 may be depressed after the indicating light L2 has been turned on. Prior to shutter release, the casing 41 is correctly positioned vertically by adjusting threaded legs 142 connccted'to the underside of the using 41: focusing and trimming are checked through the window 44.

Referring to FIG. 12, the solenoid SOL2 is deenergized when a deenergization comman is issued upon completion ofthe shutter release. This moves the actuator 139 to its extended position to thereby return the screen support arm 128 and the screcn'130 to their original positions through the connector 140, lever 137, arm and shaft 127. The switch SW5 is depressed again. The drive mechanism 104 which provides the driving power for the operations described above ineludes a gear 143 meshing with the gear 103 and substantially integral with the pulley 101 for pulling the charging device 97 by a wire 102. A worm gear 145 meshes with a gear 144 which is affixed to an end of the shaft 82 which is journalled on the support 87 and mounts the photoreceptor support plate 81. The

shafts

146 and 147 to which the gear 143 and the worm gear 145 are affixed are rotatably supported by

supporters

149 and 150 affixed to a pivotal bar 148. Secured to the

shafts

146 and 147 are gears 151 and 152 respectively which mesh with a normally rotating prime worm gear 153. The pivotal bar 148 is pivotally supported by a shaft 154 for the worm gear 153, and the range of pivotal movement of the bar 148 is defined by a fixed pin 155 received in a slot 148a formed in the bar 148.

A pin 156 is secured to a lower end portion of the pivotal bar 148 and is in engagement with a fork 157a of a selector 157. The selector 157 is supported by a shaft 158 rotatably supported by a fixed member (not shown) and includes arms 15711 and 1570 extending symmetrically therefrom to the right and to the left and connected through springs 159 and 160 to the solenoid SOLl and to another solenoid SOL3 respectively.

When both solenoids SOL] and SOL3 are deenergized, they pull on the selector 157 with equal force, and therefore the pivotal bar 148 is placed by the selector 157 in a neutral position. In this neutral position of the bar 148, the gear 143 and the worm gear 145 are away from the gear 103 and the gear 144 respectively. Assuming that the solenoid SOLI is energized upon receipt of a command to begin charging, the pivotal lever 148 is pushed by the selector 157 and moves counterclockwise about the shaft 154 to bring the gear 143 into meshing engagement with the gear 103. At this time. the pivotal bar 148 depresses with its lower portion a switch SW6 disposed to the right of the bar 148. The function of the switch SW6 is described below.

The solenoid SOLI is deenergized when the double throw switch SW41,2 is depressed by the movement of the charging device 97 from its initial position to thereby release the gear 143 from engagement with the gear 103.

After an electrostatic latent image is formed on the photoreceptor 62. the solenoid SOL3 is energized, and the pivotal bar 148 moves clockwise about the shaft 154 to bring the worm gear 145 into meshing engagement with the gear 144. This transmits the driving force of the prime worm gear 153 to the shaft 82 and rorates that shaft in the direction of the arrow (1 in FIG. 12 and simultaneously charges the coil spring 90. The rotation of the shaft 82 moves the arm means 83 in the same direction, and the support plate 81 for the photoreceptor 62 meanwhile moves in slaved relation because of the biasing force of a spring 85 to thereby move the photoreceptor 62 from the photographing position shown in solid lines in FIG. 12 to a transfer printing position.

The transfer printing position of the photoreceptor 62 is shown in dash and dot lines 62a in FIG. 20. In its tranfer-printing position, the photoreceptor 62 is in pressing engagement with the dielectric material layer of the card material 49 in order to transfer the electro-

Claims

1. A developing device for developing an electrostatic latent image formed on one side of a card material having a leading end and a traling end and having a length comparable to its width, said device comprising a developing roller having two axially spaced flanges, the axial distance between the flanges being less than the width of the card material but more than the width of the electrostatic latent image thereon, the diameter of each flange being greater than the diameter of the developing roller by a selected amount, means for rotating the developing roller, means for applying developing liquid to the developing roller, and means for moving the card material along a path tangential to the circumference of the flanges of the developing roller, with the image bearing side of the card material facing the developing roller and with the latent image thereof disposed intermediate the flanges of the developing roller, saiD moving means automatically moving the card material from a starting position in which the card material is out of contact with the developing roller, through a developing position in which at least a portion of the card material is in contact with the developing roller, and to an end position in which the card material is again out of contact with the developing roller.

2. A developing device as in claim 1 wherein the developing roller is rotated in the direction of movement of the card material and wherein the means for moving the card material includes means for preventing the trailing end of the card material from contacting the developing roller or the flanges thereof.

3. A developing device as in claim 1 wherein the developing roller is rotated in a direction opposie the direction of movement of the card material and wherein the means for moving the card material includes means for preventing the leading end of the card material from contacting the developing roller or the flanges thereof.

4. A developing device as in claim 1 wherein said moving means includes a hold-down roller and a squeezing roller disposed downstream of the developing roller along the path of the card material and facing each other, said hold-down roller including two flanges axially spaced from each other and extending radially outwardly of the hold-down roller, the distance between the facing ends of the two flanges being greater than the width of the image bearing portion of the card material but less than the width of the card material, said squeezing roller being spaced from the flanges of said hold-down roller by a distance smaller than the thickness of the card material.

5. A developing device as in claim 4 wherein the axial dimension of the squeezing roller is greater than the distance between the facing ends of the two flanges of the hold-down roller.

6. A developing device as in claim 4 wherein the axial dimension of the squeezing roller is less than the distance between the facing ends of the two flanges of the hold-down roller.

7. A developing device as in claim 1 including a blotter roller and a hold-down roller disposed downstream of the developing roller along the path of the card material, said blotter roller having an outer circumference at least equal to the length of the image bearing portion of the card material, said blotter roller disposed on the image bearing side of the card material, said hold-down roller maintained in pressing engagement with the blotter roller to nip the card material therebetween as the card material moves along its path downstream of the developing roller.