US3776629A

US3776629A - Electrophotographic duplicator

Info

Publication number: US3776629A
Application number: US00176903A
Authority: US
Inventors: M Ogawa
Original assignee: Minolta Co Ltd
Current assignee: Minolta Co Ltd
Priority date: 1971-07-08
Filing date: 1971-09-01
Publication date: 1973-12-04
Anticipated expiration: 1990-12-04

Abstract

In electrophotographic duplicators, a manuscript is disposed in a static position and an exposing device comprising an illuminating device for illuminating the manuscript is provided. The exposing device, having one of several embodiments of projection lens systems therein, is provided with a slit at the side facing the manuscript, and is slit at the side facing the light-sensitive surface. The device is caused to transfer parallel to the manuscript at a constant linear speed, and the light-sensitive surface is caused to transfer parallel to the manuscript in the same direction at a linear speed twice the transfer speed of the exposing device to form an electrostatic latent image on the light-sensitive sheet. The duplicating speed is made to be twice the speed of exposure sequentially, and operations such as succeeding development, transfer and the like can be effected at the duplicating speed.

Description

United States Patent [1 1 Ogawa Dec. 4, 1973 ELECTROPHOTOGRAPHIC DUPLICATOR Appl. No.: 176,903

Primary Examiner-Samuel S. Matthews Assistant Examiner-Kenneth C. l-lutchison AttorneyWatson, Cole, Grindle & Watson [57] ABSTRACT In electrophotographic duplicators, a manuscript is disposed in a static position and an exposing device comprising an illuminating device for illuminating the manuscript is provided. The exposing device, having I one of several embodiments of projection lens systems therein, is provided with a slit at the side facing the manuscript, and is slit at the side facing the lightsensitive surface. The device is caused to transfer parallel to the manuscript at a constant linear speed, and the light-sensitive surface is caused to transfer parallel to the manuscript in the same direction at a linear speed twice the transfer speed of the exposing device to form an electrostatic latent image on the lightsensitive sheet. The duplicating speed is made to be twice the speed of exposure sequentially, and operations such as succeeding development, transfer and the like can be efiected at the duplicating speed.

5 Claims, 6 Drawing Figures I 27 SW! 25 PAIENTEDBEE 41m 3,776,629

SHEET 1 [1F 2 INVENTOR MASAYA OGAWA MM M $4M aw-1 ATTORNEY PATENTED 4|975 3, 776,629

sum 2 0r 2 F l G. 4 Ji I U 151 'EXTUR ATTORNEY 1 ELECTROPHOTOGRAPHIC DUPLICATOR BACKGROUND OF THE INVENTION In prior art electrophotographic duplicators, as a means of forming the electrostatic latent image on the light-sensitive sheet by projecting the image of the manuscript on the light-sensitive sheet, the following is normally provided:

1. a total picture surface exposing type in which the exposure is effected in the conditions where the manuscript, exposing device, and light-sensitive sheet are all in a static state;

2. a so-called manuscript table transfer type in which the manuscript and light sensitive paper are transferred with respect to the static exposing device at the same speed; and

3. a so-called optical system transfer type in which the manuscript and light-sensitive sheet are in a static state and the exposing device is transferred parallel thereto at a constant speed.

The electrophotographic duplicator of the type (1) projects the total picture surface of the manuscript simultaneously and, therefore, there are drawbacks in that its illuminating device is required to be strong, the projection lens system must be enlarged, and consequently the size of the duplicator becomes large and, where the electrostatic latent image formed on the light-sensitive sheet is transferred to the transfer paper with the latent image as it is or after the latent image is developed, and the light-sensitivev sheet is fixed on the endless belt or the light-sensitive sheet is used repeatedly by making it in endless form, transfer of the light-sensitive sheet has to be stopped-every time the exposure is made, whereby the operations of the system Also, the electrophotographic duplicator of type (3 requires the light-sensitive sheet to be static whenever the exposure is effected which is a drawback identical with the one described in the above-mentioned type (1 Also, the duplicating speed is slow.

On the other hand, as is observed in US Patent application Ser. No. 306295, now abandoned, there is type (4) whichis the improved optical system transfer system of the above-mentioned type (3) in which the exposing device and the light-sensitive sheet are transferred while the manuscript is made static.

The present invention relates to electrophotographic duplicators of the slit scanning type, which is an improvement of the optical system transfer type of the type (4) mentioned in the foregoing, and more particularly to elecrophotographic duplicators which improve duplicating speed and maintain the length of optical path of the projection'lens system accurately and constantly so as to obtain an image with high resolving power.

The present invention is constructed in such a way that the exposing device, provided with a slit at the side of manuscript, illuminating device, andprojection lens system and another slit at the side of light-sensitive surface, is transferred parallel to the static manuscript at a fixed linear speed. The light-sensitive sheet is caused to transfer at a linear speed twice that of the exposing device in the same direction parallel to the manuscript, and the duplicating speed is made twice as fast as compared with the exposure speed; the operations of succeeding development, transfer and the like can be effected at the duplicating speed.

OBJECTS OF THE INVENTION An object of the present invention is to provide electrophotographic duplicators with improved duplicating speed.

Another object of the present invention is to provide high speed electrophotographic duplicators where the exposing device, having the illuminating device, the projection optical system and slit at the light-sensitive surface integrally, is caused to transfer with respect to the manuscript, and the electrostatic latent image of the manuscript is formed on the transferring lightsensitive sheet.

A further object of the present invention is to provide high speed electrophotographic duplicators where the transfer light-sensitive sheet is arranged to be twice as fast as the exposure speed.

. A still further object of the present invention is to provide high speed electrophotographic duplicators where a light of an endless belt type or a light-sensitive sheet fixed on an endless belt, which transfers on a surface having a length almost identical with the 'manu script table, is disposed so as to face the manuscript and developer is disposed in the transfer surface of the underside of the endless belt.

One of the other various objects of thepresent invention is to provide one construction of latent image transfer typeelectrophotographic duplicators of the table type having high duplicating speed.

SUMMARY OF THE INVENTION The present invention relates to small size electrophotographic duplicators which achieve the various objects mentioned in the foregoing, in which the manuscript is disposed in a static state and the exposing device, comprising the illuminating device for illuminating the manuscript, a slit at the'side of manuscript facing the manuscript, a projection optical system, and a slit at the side of light-sensitive sheet, is caused to transfer parallel to the manuscript at a constant linear speed. The light-sensitive sheet facing the slit is caused to transfer in the same direction with a speed twice that of the speed of the exposing device. Also, assuming that the transfer speed of the illuminated optical image for the manuscript, namely,-the exposing speed, is V, the duplicating speed becomes twice the exposing speed as the light-sensitive sheet is transferred at the speed of 2 V, and thus the initial copy speed can be quickened.

The exposing device is required to make a reciprocating motion as a matter of course when repeating reproductions are made, but is not necessary that the returning motion be made a constant speed. Also, it is possible to minimize the impact force even if the speed of the returning motion is increased by increasing the accelerations positively and negatively and therefore any efficiency decrease due to the returning motion can be substantially minimized.

Also, in electrostatic latent image formation in accordance with the present invention, where the projection optical system is designed as a optical system for projecting a positive image, and the light-sensitive sheet is designed as light-sensitive paperof sheet type as found in the electrofax, the electrostatic latent image to be formed is directly developed and, thus, copying of the latent image is made possible. Also, the projecting optical system is designed as an optical system for projecting a mirror image, so that it becomes a latent image transfer type of electrophotographic duplicator or a toner transfer type of electrophotographic duplicator.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of an essential portion showing the principal construction of the electrophotographic duplicator of the type wherein the lightsensitive sheet according to the present invention is directly copied.

FIG. 2 is a cross-sectional side view showing an es sential portion of one embodiment of the electrophotographic duplicators of the above-mentioned type according to the present invention.

FIG. 3 is a schematic illustration of an essential portion showing another embodiment of the electrophotographic duplicator of the above-mentioned type according to the present invention.

FIG. 4 is a schematic illustration of an essential portion showing still another embodiment of the present invention.

FIG. 5 is a schematic illustration showing'the principal construction of the latent image transfer 'type ac- DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a schematic illustration showing the principal construction of one embodiment of an electrophotographic duplicator of the electrofax type according to the present invention.

In the electrophotographic duplicator, reference numeral l designates a manuscript to be disposed .in a static state. In the manuscript, a picture a to be copied is described at its one end and a picture b to be copied is described at its the other end.

On the contrary, reference numeral 3 shown by a solid line denotes an exposing device in a position at time the exposure is started, and a dotted line 3 denotes the positionof the exposing device at the time of completion of its exposure.

Similarly, reference numeral 2 shown by the solid line denotes the position of a light-sensitive sheet 2 at the time the exposure is started and the dotted line 2 denotes the position of the light-sensitive sheet 2 at the time the exposure is completed.

The exposing device 3 comprises an illuminating device 4 for illuminating manuscript 1 locally, a slit 5 at the side of the exposing device facing the manuscript in the vicinity thereof, a slit 9 at the side of the exposing device facing the light-sensitive sheet 2 in the vicinity thereof, a roof mirror lens 8 with a roof mirror 7 therein and a reflecting mirror 6 within the exposing device. Exposing device 3 is constructed in such a way that when the device 3 transfers parallel to manuscript 1 at a linear speed V shown by an arrow mark, and rays of light of manuscript 1 illuminated by slit 5 at the side of the manuscript enter through slit 5 and its image forming rays of light are emitted from slit 9 at the side of the light-sensitive sheet by means of roof mirror lens 8 and reflecting mirror 6 to form an image on lightsensitive sheet 2.

Accordingly, when light-sensitive sheet 2 transfers parallel to the manuscript in the same direction as shown by the arrow mark but at a speed 2 V, i.e., twice the transfer speed V of the exposing device 3, the picture a at the right end of the manuscript 1 forms a'positive image a of a size equal to the picture a at the tip of the light-sensitive sheet 2, and the picture b at the left end of the manuscript 1 forms a positive image b of a size equal to the picture b at the rear end of the light-sensitive sheet 2 just before the completion of the exposure. Thus, an equal size reproduction of manuscript 1 is formed on light-sensitive sheet 2 and the corresponding electrostatic latent image can be obtained.

FIG. 2 is a cross-sectional side view showing the construction of an essential portion of one embodiment of the electrophotographic duplicator of the electrofax type employing the above-mentioned principle. Elements identical to those of FIG. 1 are referenced the same. Reference numeral 1 denotes a manuscript such as a books the manuscript being placed in a static position on the table 11 for exposure, the table comprising a transparent flat plate disposed on the upper surface of a casing 10 of the duplicator.

The exposing device 3 is constructed in such a way I that

rollers

12, 12 on opposite side portions thereof are rotated on a guide rail 13 parallel to table 11 thereby allowing device 3 to be transferred parallel to the table.

Pins 14, 14' located the front and rear sides of exposing device 3 are respectively connected to opposite ends of a rope 15, the rope being stretched over a pulley 17 of a drive motor 16 and above pulleys 18, 18' of the casing l0.

Within casing 10, return switch SW1 and stop switch SW2 are fixed at both ends of a transfer path of exposing device 3 in which slit 5 at the side of the manuscript of the exposing device scans from the one end to the other end of manuscript 1. When the return switch SW1 is actuated by exposing device 3 which reciprocates by means of drive motor 16 in the direction shown by the arrow mark, the exposure is completed. With 'a reverse rotation of drive motor 16 exposing device 3 returns and, when its returning motion is completed, stop switch SW2 is actuated and exposing device 3 is ready to effect the next exposure.

Incidentally, return switch SW1 may be arranged as the motor stop switch and the returning of the exposing device is carried out by the accumulated power of the spring 19.

At underside of the slit 9 at the side, of the lightsensitive sheet of exposing device 3, a carrier pathis provided as having a length substantially the same as that of manuscript table 11. This carrier path constitutes a carrier belt comprising an endless belt 21 supported for movement about spaced rollers 20 and 20'.

The carrier path at the upper side of carrier belt 21 is arranged to be parallel with manuscript table 11 and guide rail 13. The rollers 20, are driven by a drive motor 27 and are rotated in the same direction and at a linear speed twice the speed of reciprocating motion of exposing device 3 for driving carrier belt 21.

A microswitch SW3 for actuation of motor 16 is arranged to actuate the scanning by the reciprocating motion of exposing device 3 at the side of roller 20 of carrier belt 21.

The light-sensitive paper sheets 2 stacked and housed within a cassette 23 are fed one sheet at a time by means of a roller 24, and are fed onto carrier belt 21 through a charger 22 fixed within casing 10.

On the other hand, a liquid developer 25, drier 26 and discharge stand 28 are disposed immediately behind roller 20', and each of these units is arranged linearly with the carrier belt 21.

Accordingly, when the charged light-sensitive paper 2 placed on carrier belt 21 is fed toward the left at a speed 2 V, microswitch SW3 is switched on, exposing device 3 is actuated by drive motor 16, and the exposing device 3 is transferred in the direction shown by the arrow mark at a speed V. Manuscript 1 is scanned sequentially from the right hand direction with exposing device 3, and its image is formed on light-sensitive paper 2 carried to the left hand direction at a speed 2 V by means of mirror 6 and roof mirror lens 8 so as to form an electrostatic'latent image consisting of a positive image of a size equal to the size of the manuscript 1. When its rear end approaches roller 20, slit 5 at the side of the manuscript of exposing device 3 completes the scanning of manuscript 1 and light-sensitive paper 2 is fed continuously to the liquid developer tank of developer 25 at the same speed 2 V passes beneath drier 26 and is fed to discharge stand 28.

Accordingly, each process of the feeding, exposing, developing, and drying of light-sensitive paper 2 is effected entirely at the speed 2 V.

On the other hand, when exposing device 3 completes the scanning of manuscript 1, switch SW2 is actuated so as to return device 3 to its initial position, as shown in solid lines rapidly by means of the force of drive motor 16 reversely rotating'or by means of energized spring 19, and is set to be ready for the next reproduction.

FIG. 3 shows another embodiment in block diagram in which the projection optical system comprising the reflecting

mirrors

6,, 6,, 6, and roof mirror lens 8 is employed for minimizing an interval between manuscript 1 and light-sensitive paper 2 and obtaining a necessary length of the optical path.

FIG. 4 shows the construction in which the projecting optical system formed by combining an ordinary image forming lens 8 instead of using the mirror lens with the reflecting mirror 6 and a roof prism 7'. Here, also, the positive image of manuscript 1 can be obtained on light-sensitive paper 2. In each of the foregoing embodiments, manuscript 1 is in a static position, and exposing device 3 scans manuscript 1 while it transfers in the direction shown by the arrow mark at a speed V. The light-sensitive paper 2 transfers at a speed 2 V in the same direction by being synchronized with the scanning.

FIGS. 5 and 6 show an embodiment of the electrophotgraphic duplicator of the transfer type, these figures being electronic duplicators of the latent image transfer type and FIG. 5 being a block diagram showing its principle.

FIG. 6 is a cross sectional side view showingthe construction of an essential portion of one embodiment. The construction is identical or equivalent with those shown in FIG. 1 through FIG. 5 and like elements are shown with identical symbols.

The exposing device 3 comprising the illuminating device 4, slit 5 at the side of the manuscript, projection lens system 8 and slit 9 at the side of the light-sensitive sheet is caused to transfer in the direction shown by the arrow mark parallel to manuscript 1 at a speed V with respect to manuscript 1 which is in a static position. When light-sensitive sheet 2 is simultaneously transferred in the same direction shown by the arrow mark parallel thereto at the speed 2 V, and the slit 5 at the side of manuscript of the exposing device 3 scans the right end of manuscript 1', projecting lens 8 forms its picture a on light-sensitive sheet 2 as a mirror image a", and forms an inverted reversal mirror image b", of the picture b at the left end of manuscript 1 on lightsensitive sheet 2. The electrostatic latent image of the mirror image for manuscript 1 is formed on lightsensitive sheet 2.

Now, transfer paper sheets 30 which transfer in the same direction at speed 2 V identical with that of lightsensitive sheet 2, is abutted on light-sensitive sheet 2,

and are applied with pressure by roller 20', and a transfer roller 32 which are grounded. The electrostatic latent image of the positive image is formed on transfer paper 30, and the toner is caused to adhere by causing the transfer paper 30 to pass through the developer 25 at speed 2 V whereby the development can be effected.

FIG. 6 shows an embodiment of the latent image transfer type electronic duplicator employing the construction based on the above-mentioned principle, in which the manuscript 1 is placed immovably on manuscript. table 11 comprising a transparent plate on the upper surface of casing 10 of the duplicator in the same manner as in the embodiment shown in FIG. 2. Exposing device 3 employs two sheets of the

plane reflecting mirrors

6,, 6, in addition to the projection lens system 8 so as to obtain sufficient length of the optical path by minimizing its thickness.

The exposing device 3 is transferred (not shown) parallel to manuscript 1, in the direction shown by the arrow mark, at a constant linear speed V by means of the drive motor as in the case of the embodiment shown in FIG. 2. Slit 5 at the side of the manuscript scans manuscript 1 to be locally illuminated with illuminating device 4 from the right side to the left side.

Consequently, the picture of manuscript 1 enters from slit 5 at the side of the manuscript and is reflected by means of reflecting mirror 6,, and its image forming rays of light by means of projection lens system 8 is reflected by reflecting mirror 6 and is emitted from slit 9 at the side of the light-sensitive sheet.

The light-sensitive sheet 2 is disposed parallel to manuscript 1 and is wound on two pieces of drive rollers 20, 20' disposed in nearly same distance between the manuscript and light-sensitive sheet, or is fixed on the endless belt wound on the roller, and is transferred so as to circulate in the direction of the arrow mark at speed 2 V as in the case of the embodiment shown in FIG. 2 by means of the drive motor, not shown in the drawing. Therefore, the mirror image of manuscript 1 is sequentially formed on light-sensitive sheet 2 and its electrostatic latent image is formed thereon.

in synchronizing with the reaching of the tip of the electrostatic latent image formed on light-sensitive sheet 2 to roller to be grounded, one sheet of the upper side of transfer paper sheets 30, which are stacked and housed in cassette 29, are fed by means of roller 31 at speed 2 V. Transfer paper is urged against light-sensitive sheet 2 with transfer roller 32, which is grounded and is urged against roller 20, and the electrostatic latent image of the mirror image on light-sensitive sheet 2 is transferred electrostatically on transfer paper 30 as the positive image.

The transfer paper 30. which has been transferred is fed to developing tank 25 of developer 25 with roller 33 at speed 2 V, is developed therein, is moved on to belt 35, belted about the rollers 36 and 36', by means of roller 33' at the same speed is dried, by means of drier 26, and is discharged on discharge stand 38.

Incidentally, as shown in the drawings, in the duplicators in which light-sensitive sheet 2 is moved endlessly, instead of fixing the charger in the casing of the duplicator, it may be disposed at the rear part of the slit at the side of the light-sensitive sheet in the scanning direction of exposing device 3.

What is claimed is:

1. An electrophotographic duplicator of the electrofax type, comprising:

a transparent plate for supporting a manuscript thereon to be copied in a static position;

an exposing device located beneath said transparent plate and being movable in a direction parallel to said plate;

means for moving said exposing device in a forward and reverse direction at a constant first linear speed from one end of said plate to the other;

an illuminating element on said exposing device for illuminating the manuscript through said plate; one side of said-exposingv device which faces said plate having a first slit therein;

movable conveyor means located adjacent an oppo-- site side of said exposing device for transferring a light sensitive sheet having substantially an equal length to that of said plate in a plane parallel to said plate in the same forward and reverse direction as said exposing device and at a second constant linear speed twice that of said first speed;

said opposite side of said exposing device having a second slit therein; and

an optical system located between said first slit and second slit within said exposing device including a projecting lens system the optical axis of which is directed parallel to the direction of movement of said exposing device, a mirror facing said first slit and being inclined to said plate and said sheet at an angle of 45 for reflecting light passing through said first slit vertically from the manuscript to said projecting lens system, and roof reflecting means facing said second slit having two reflecting surfaces crossing each other at right angles, the crossing edge of said reflecting means being inclined to said plate and said sheet at an angle of 45 for reflecting light along said optical axis of and from said projecting lens system to said second slit.

2. An electrophotographic duplicator of the electrofax type, comprising:

an illuminating element on said exposing device for illuminating the manuscript through said plate;

one side of said exposing device which faces said plate having a first slit therein;

movable conveyor means located adjacent an opposite side of said exposing device for transferring a light sensitive sheet havingsubstantially an equal length to that of said plate in a plane parallel to said plate in the same forward and reverse'direction as said exposing device and at a second constant linear speed twice' that of said first speed;

said opposite side of said exposing device having a second slit therein; and

an optical system located between said first slit and second slit within said exposing device including a mirror-lens system comprising a lens system the optical axis of which is perpendicular to said plate and said sheet, and a roof mirror system having two reflecting surfaces crossing each otherat right angles and the crossing edge of which faces said second slit to reflect light passing through said lens system to said second slit and a flat mirror facing said first slit parallel to said plate and said sheet for reflecting light passed through said first slit from the manuscript to said mirror-lens system.

3. An electrophotographic duplicator of the electrofax type, comprising:

a transparent plate for supporting manuscript thereon to be copied in a static position;

an exposing device located beneath said transparent plate and being movable parallel to said plate;

means for moving said exposing device in a forward and reverse direction at a constant *first linear speed from one end of said plate to the other;

movable conveyor means located adjacent an opposite side of said exposing device for transferring a light sensitive sheet having substantially an equal length to that of said plate in a plane parallel to said plate in the same forward and reverse direction as said exposing device and at a second constant linear speed twice that of said first speed;

said opposite side of said exposing device having a second slit therein; and

an optical system located between said first slit and said second slit within said exposing device including a mirror-lens system comprising a lens system the optical axis of which is parallel to said direction of movementof said exposing device, and a roof mirror system having two reflecting surfaces each of which crosses said direction of movement of said exposing device at an angle of 45 degrees, and the crossing edge of said both reflecting surfaces being directed perpendicularly to said direction ofmovemerit of said exposing device, a first flat mirror facing said first slit and a second flat mirror perpendicular to said direction of movement for serially reflecting light passing through said first slit from the manuscript to said mirror-lens system, and a third flat mirror facing said second slit for reflecting said light reflected in said mirror-lens system to said second slit.

4. An electrophotographic transfer type duplicator comprising:

an exposing device located parallel to and beneath said transparent plate and being movable in a direction parallel to said plate;

means for moving said exposing device in a forward and reverse direction at a first linear speed from one end of said plate to the other;

an illuminating device on said exposing device for illuminating the manuscript through said plate;

movable conveyor means located on the opposite side to said exposing device and comprising an endless belt of a light sensitive sheet and a pair of rollers spaced apart a distance substantially equal to the length of said plate, wherein the side of said belt facing said exposing device which travels around said rollers is driven parallel to the forward direction of said exposing device and at a second speed twice that of the first speed, and one roller in the forward direction of said pair of rollers is a first grounded conductive roller;

said opposite side of said exposing device having a second slit therein;

a projection optical system located between said first slit and said second slit within said exposing device including a mirror and lens system forming a positive inverted image from the manuscript onto said light sensitive sheet;

a charging device integrally formed on said exposing device and located rearwardly of said second slit in the forward movable direction of said exposing device;

a receptacle for sheets of transfer paper disposed forwardly of said movable conveyor means;

means for feeding the transfer sheets in the rearward direction at a constant linear speed twice that of said first speed; and

a transfer device including a second grounded conductive roller in contact with said first grounded conductive roller of said movable conveyor means for urging said fed transfer sheets against said light sensitive sheet.

5. The duplicator according to claim 4 further comprising a developer disposed beneath said endless belt, and further means for feeding the transfer sheets from between said transfer device and said belt into said developer at a constant linear speed twice that of said first speed.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. I 3,776,629

D T I December 4, 1973 INVENTOR( I Masaya Ogawa It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the Title Page, under the heading "Foreign Application Priority Data", cancel "July 8, 1971....

Japan U. 46/22189" and substitute:

-- September 15, 1970 Japan 45-91484 June 19, 1971 Japan 46-52823 Signed and Scaled this Fourth Day of April 1978 [SI-AL] Arrest:

Rl'TH MASON Ll'TRELLE F. PARKER Attesting Officer Acting Commissioner of Patents and Trademarks i, UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,776,629

D TED December 4, 1973 I |NVENTOR(S) Masaya Ogawa It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the Title Page, under the heading "Foreign Application Priority Data", cancel "July 8, 1971...

Japan U. 46/22189" and substitute:

' September 15, 1970 Japan 45-91484 June 19, 1971 Japan 46-52823 Signed and Scaled this Fourth Day of April 1978 |SI-IAL| Am'st:

Rl'TH (I MASON LI'IRELLE F. PARKER Arresting Officer Acting Commissioner of Patents and Trademarks

Claims

1. An electrophotographic duplicator of the electrofax type, comprising: a transparent plate for supporting a manuscript thereon to be copied in a static position; an exposing device located beneath said transparent plate and being movable in a direction parallel to said plate; means for moving said exposing device in a forward and reverse direction at a constant first linear speed from one end of said plate to the other; an illuminating element on said exposing device for illuminating the manuscript through said plate; one side of said exposing device which faces said plate having a first slit therein; movable convEyor means located adjacent an opposite side of said exposing device for transferring a light sensitive sheet having substantially an equal length to that of said plate in a plane parallel to said plate in the same forward and reverse direction as said exposing device and at a second constant linear speed twice that of said first speed; said opposite side of said exposing device having a second slit therein; and an optical system located between said first slit and second slit within said exposing device including a projecting lens system the optical axis of which is directed parallel to the direction of movement of said exposing device, a mirror facing said first slit and being inclined to said plate and said sheet at an angle of 45* for reflecting light passing through said first slit vertically from the manuscript to said projecting lens system, and roof reflecting means facing said second slit having two reflecting surfaces crossing each other at right angles, the crossing edge of said reflecting means being inclined to said plate and said sheet at an angle of 45* for reflecting light along said optical axis of and from said projecting lens system to said second slit.

2. An electrophotographic duplicator of the electrofax type, comprising: a transparent plate for supporting a manuscript thereon to be copied in a static position; an exposing device located beneath said transparent plate and being movable in a direction parallel to said plate; means for moving said exposing device in a forward and reverse direction at a constant first linear speed from one end of said plate to the other; an illuminating element on said exposing device for illuminating the manuscript through said plate; one side of said exposing device which faces said plate having a first slit therein; movable conveyor means located adjacent an opposite side of said exposing device for transferring a light sensitive sheet having substantially an equal length to that of said plate in a plane parallel to said plate in the same forward and reverse direction as said exposing device and at a second constant linear speed twice that of said first speed; said opposite side of said exposing device having a second slit therein; and an optical system located between said first slit and second slit within said exposing device including a mirror-lens system comprising a lens system the optical axis of which is perpendicular to said plate and said sheet, and a roof mirror system having two reflecting surfaces crossing each other at right angles and the crossing edge of which faces said second slit to reflect light passing through said lens system to said second slit and a flat mirror facing said first slit parallel to said plate and said sheet for reflecting light passed through said first slit from the manuscript to said mirror-lens system.

3. An electrophotographic duplicator of the electrofax type, comprising: a transparent plate for supporting manuscript thereon to be copied in a static position; an exposing device located beneath said transparent plate and being movable parallel to said plate; means for moving said exposing device in a forward and reverse direction at a constant first linear speed from one end of said plate to the other; an illuminating element on said exposing device for illuminating the manuscript through said plate; one side of said exposing device which faces said plate having a first slit therein; movable conveyor means located adjacent an opposite side of said exposing device for transferring a light sensitive sheet having substantially an equal length to that of said plate in a plane parallel to said plate in the same forward and reverse direction as said exposing device and at a second constant linear speed twice that of said first speed; said opposite side of said exposing device having a second slit therein; and an optical system located between said first slit and said seCond slit within said exposing device including a mirror-lens system comprising a lens system the optical axis of which is parallel to said direction of movement of said exposing device, and a roof mirror system having two reflecting surfaces each of which crosses said direction of movement of said exposing device at an angle of 45 degrees, and the crossing edge of said both reflecting surfaces being directed perpendicularly to said direction of movement of said exposing device, a first flat mirror facing said first slit and a second flat mirror perpendicular to said direction of movement for serially reflecting light passing through said first slit from the manuscript to said mirror-lens system, and a third flat mirror facing said second slit for reflecting said light reflected in said mirror-lens system to said second slit.

4. An electrophotographic transfer type duplicator comprising: a transparent plate for supporting a manuscript thereon to be copied in a static position; an exposing device located parallel to and beneath said transparent plate and being movable in a direction parallel to said plate; means for moving said exposing device in a forward and reverse direction at a first linear speed from one end of said plate to the other; an illuminating device on said exposing device for illuminating the manuscript through said plate; one side of said exposing device which faces said plate having a first slit therein; movable conveyor means located on the opposite side to said exposing device and comprising an endless belt of a light sensitive sheet and a pair of rollers spaced apart a distance substantially equal to the length of said plate, wherein the side of said belt facing said exposing device which travels around said rollers is driven parallel to the forward direction of said exposing device and at a second speed twice that of the first speed, and one roller in the forward direction of said pair of rollers is a first grounded conductive roller; said opposite side of said exposing device having a second slit therein; a projection optical system located between said first slit and said second slit within said exposing device including a mirror and lens system forming a positive inverted image from the manuscript onto said light sensitive sheet; a charging device integrally formed on said exposing device and located rearwardly of said second slit in the forward movable direction of said exposing device; a receptacle for sheets of transfer paper disposed forwardly of said movable conveyor means; means for feeding the transfer sheets in the rearward direction at a constant linear speed twice that of said first speed; and a transfer device including a second grounded conductive roller in contact with said first grounded conductive roller of said movable conveyor means for urging said fed transfer sheets against said light sensitive sheet.