CA1267024A - Microfilm reader-printer - Google Patents

Abstract

MICROFILM READER-PRINTER
Abstract of the Disclosure A microfilm reader-printer for use with dry silver paper to produce paper copies of selected images. During the printing process, ambient light is excluded from inside the reader-printer by swinging cafe doors. A controller and series of motors control the operation of all paper feeding, imaging, developing and viewing functions. The unique and simple paper feeding and developing systems provide an extremely economical reader-printer.

Description

~2670~4 MICROFILM READER-PRINTER
BACKGROUND OP THE INVENTION
This invention relates to microfilm reader-printers and, more particularly, to reader-printers that produce paper copies of images using a light sensitive media that is developed by heat.
With the increasing amount of information that must be stored and readily available to business~
es, government and the general public, microfilm has become a very common and important storage media.
Microfilm enables large quantities of documents, data, or graphics to be stored in relatively small spaces.
Microfilm can be stored in several configurations.
One form is commonly referred to as microfilm jackets, in which individual strips of film are placed between two transparent plastic sheets having channels to accept and retain tbe film. A second form similar to microfilm jackets is microfiche in which a piece of material approximately 4 inches by 6 inches has the information disposed ther~on. Microfiche can also be made by a duplicating process from an original micro-film jacket. The size of the microfiche can vary, however, the concept encompasses placing multiple images on a single card or fiche. Another form has a card with a rectangular cut therein holding an indivi-dual piece of film, commonly referred to as an aperture card. The images may also be retained on rolls of microfilm which are stored in cartridges or cassettes for later retrieval.
There are basically two types of microfilm readers used to project the images onto a screen for viewing by an observer. The first type, commonly referred to as the "rear projection" type, uses a translucent screen which has the image projected on the read surface of it for viewing by the observer.
The second type, commonly known as the "front projec-tion" type, projects the microfilm image onto a screenwhich is viewed by the observer from the same side on which the i~age is projected. The observer thereby sees the image via reflected light rather than trans-mitted light as in the rear projection type. Although the present invention is designed for use with micro-film jackets, microfiche, or aperture cards, it could ~e adapted for use with roll microfilm which is stored in cartridges or cassettes.
Oftentimes the user desires to have a per-manent record on paper of an image which he has beenviewing. The apparatus to view and to provide the copy is commonly known as a reader-printer. There are two common methods by which the paper copy is created. The first uses the electro-photographic process in which a uniformly charged photo-conductive sheet of paper is exposed to the image. The charge on the surface is dissipated depending upon the pre-sence or absence of light This produces a charge distribution on the surface which coincides with the image. The exposed charged surface is then placed in contact with toner particles which are attracted to the charged surface depending upon the magnitude of the charge remaining on the sheet. The toner particles are then fixed to the charged surface and a paper copy is produced.
In the second process a light sensitive imaging surface, commonly a dry silver material, is i'7~

kept in a light-tight enclosure until it is to be used. The dry silver sheet is then exposed to the image. The exposed sheet is transported to a develop-ing station where it is subjected to heat which de-velops the latent image. The paper copy i5 produced without the need of separately charging and toning the sheet such as is required in the electro photo-graphic process. As can be readily appreciated the dry silver process requires less sophisticated equip-ment than is required`in the photo-conductive process.
Charging, toning and fusing stations are not required.
- The only requirement is that the dry silver paper be kept in a light-tight enclosure until it is exposed and then subjected to a uniform heating device for developing.
The present invention relates to a newly designed reader-printer which, because of its unique design, provides an extremely economical and efficient front projection reader-printer for use with the dry silver copying process.
SUMMARY OF THE INVENTION
The present invention is a new and improved reader-printer that is extremely simple in its design and operation resulting in a reader-printer which is more economical to manufacture than any previous unit.
The device a~cording to the present invention provides a reader-printer which is simple and easy to operate~
has a minimum number of operator adjustments and is extremely compact when compared to other reader-prin-ters. In the viewing mode, the image is projectedonto a viewing screen or easel which is viewed by the user. When a print of the image is desired, the opera-tor moves a switch on the front of the reader from a viewing mode to the print mode. In the print mode, the image continues to be projected onto the viewing screen. The operator then pushes a print button which initiates the print cycle. A timing motor is activated ~67~)24 which operates a cam and linkage arrangement to close a pair of cafe doors in the front of the reade~-prin-ter. ~his seals off ambient light from the viewing screen. The projection lamp is momentarily deenergi~ed while a sheet of light sensitive dry silver paper is fed and positioned onto the viewing screen. The pro-jection lamp is momentarily energized to project the image onto the light sensitive dry silver paper. The lamp is again momentarily deenergized while the dry silver paper with a latent image thereon is fed to a developing station. The paper passes around a roller which is adjacent a heating shoe and the image is - developed by heat. The paper is then ejected to a receiving tray. The cafe doors reopen and the projec-tion lamp is again energi~ed projecting the image onto the viewing screen.
The timing se~uence and opera~ion of the printing steps is accomplished by means of a timer motor and controller. Separate motors are used for feeding paper from a cassette to paper feed rollers which move the paper onto the viewing screen. A separ-ate developer motor rotates the developing roller to transport the paper through the developer.
Accordingly the invention seeks to provide a front projection microfilm reader-printer which utilizes a simplified system for producing paper copies of the images. Further, the invention seeks to provide a microfilm reader-printer having a minimum number of operat,or adjustments to further simplify making paper copies and which utilizes light sensitive dry siIver paper to produce copies of the micro~ilm images. An advantage of using dry silver paper is that it simplifies the apparatus ~or the imaging and development processes.
Various aspects of the invention are claimed and in one aspect the invention pertains to a control circuit for apparatus for reading or printing images from a microimage record comprising a control switch for selecting a view mode or a print mode, a print switch for initiating a copy print se~uence and a first circuit energized by operation of the control switch to the view mode for projecting a viewable image of the microimage record. A second circuit is energized by operation of the control switch to the print mode and operation of ~6~)2~

-~A-the print switch for carrying out a copy print sequence.
Sequence timer means in the second circuit is energized by operation of the print switch for controlling a timer cycle including copy feed, exposure and developer operations and a circuit branch is connected between the first and second circuits for maintaining operation of the sequence timer means during a timer cycle in response to operation of the control switch from the print mode to the view mode prior to completion of the timer cycle.
A further aspect of the invention comprehends a microimage reader-printer comprising a housing, a viewing screen disposed at a fixed location within the housing, means for projecting images onto the viewing screen, the housing having viewing means for permitting a viewer to view the viewing screen and the viewing means having means for controlling the passage of light therethrough. Means are provided for holding a supply of light sensitive sheets, and there is means for transporting the light sensitive sheets individually from the supply holding means onto the surface of the fixed viewing screen for exposure by the projecting means and to transporting the sheets to a developing station.
Control means is responsive to a print signal for sequentially rendering the projecting means operative to disable the lamp means, operating the transporting means to transport one of the sheets from the holding means onto the fixed viewing screen, rendering the projecting means operative to enable the lamp means to project an image onto the sheet present on the fixed viewing screen to expose the sheet, rendering the projecting means operative to disable the lamp means, operating the transporting means to transport the sheet to the developing station for development, and rendering the projecting means operative to enable the lamp means to project an image onto the vlewlng screen.
Other aspects of the invention will become more apparent from the detailed description herein.

3 ~ O~

BRIEF DESCRIPTION OF THE DRAWING
_ Other objects and advantages of the invention will become apparent upon consideration of the follow-ing detailed description and reference to the drawing, in which:
FIG. 1 is a perspective view of the microfilm reader-printer with the outer housing o~ the reader-printer removed for clarity;
FIG. 2 is a front elevational view of tha reader-printer shown in FIG. l;
FIG. 3 is a right side view of the reader-- printer;
FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2 with portions removed for clarity;
FIG. 5 is a schematic diagram of the control circuit oE the reader-printer of FIG. l; and FIG. 6 is a diagrammatic illustration of the sequence timer and timing sequence chart for the control circuit of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION

Turning first to FIG. 1 there is illustrated a microfilm reader-printer 10 illustrating the present invention. The outer housing has been removed to expose a portion of the internal operating mechanism.
The reader-printer 10 has a frame 12 and a base portion 14 having fiche carriage 16 mounted thereon. The fiche carriage 16 receives the fiche (not illustrated) which has the individual images thereon. The carriage 16 can move in the horizontal plane to position any of the desired images for viewing.
As seen in FIG. 4, the base portion 14 en-closes a projection lamp 18, a first mirror 20 and a condenser lens 22. A pair of glass flats 24 receives the fiche and is positioned above the condenser lens 22. The beam of light from the lamp 18 is reflected upward through the fiche and the image from the fiche is projected through an objective lens 26 to a second ~;~6~02~
mirror 28 mounted to the frame 12. The image is then reflected onto a viewing screen or easel 30 within the reader-printer 10. The viewing screen 30 is placed at an appropriate angle so that the user can easily observe the image projected on the screen 30 through an opening or window 32 in the frame 12 at the front of the reader-printer 10. A ~ocusing knob 33 is con-nected to and controls a focusing mechanism that moves the objective lens 26. This E~rojection system is common to front projection microfilm readers.
As seen in FIGS. 1, 3 and 4 there is a paper tray 3g adapted to receive a light-tight cassette 35 containing dry silver photographic imaging paper. To provide acceptable copies, the dry silver paper must not be exposed to stray ambient light before or during the printing cycle.
To seal off ~he ambient light from passing through the window 32 there are a pair of cafe doors 36 which close during the printing process. The door

2~ closing mechanism is best illustrated in FIGS. 1 and

3. During the print cycle a timing motor 38 causes a cam 40 to rotate in the direction of arrow A (the clockwise direction as seen in FIG. 3). A spring 42 which is in tension has one end mounted to the frame 12 and the other end mounted to a first link 44. As the cam 40 rotates, a follower 4S on the first link 44 follows the cam profile. The spring 42 causes the fi~st link 44 to pivot about pivot point 47 as the follower 46 follows the abrupt drop-off 4~ on cam 40.
30 Thus, the end of the link 44 closest to the cam 40 drops downward raising an opposite end 50 of the link 44.
A connecting pin 52 at the end 50 is con-nected to a connecting link 54. As the end 50 is raised, the connecting link 54 rotates in the direction of arrow B. The end of the connecting link 54 opposite the connecting pin 52 is connected to a rotatable ~2t~70~:~

_7_ control shaft 56. Rigidly mounted to the control shaft 56 are a pair of door control levers 58 which pivot in holes in the cafe door assembly 36. When the shaft 56 is rotated clockwise the doors 36 will be urged to an open position. When the shaft 56 is rotated counterclockwise the door 36 will be uryed to a closed position.
Tbe path followed by the dry silver paper through the reader-printer 10 is best illustrated in lQ FIG. 4. The light-tight cassette 35 holding the dry silver paper is placed on the Ipaper tray 34. A spring - 62 forces the paper up against a pair of cassette feed rollers 64 that are mounted to a shaft S6. The cassette has two holes or slots (not illus~rated) that are in alignment with the cassette feed rollers 64. One end of the shaft 66 is connected to a cassette feed roller motor 68 (FIG. 2). The cassette feed rollers 64 are mounted to the shaft 66. The shaft 66 is connected to a clutch assembly that causes the feed roller 64 to drive the top sheet of paper in the paper feed direction when the motor is energized, yet allow the cassette feed roller 64 to freely rotate when the feed motor 68 is deenergized.
At the beginning of the print cycle, the cassette feed motor 68 momentarily drives the feed rollers 64 causing the top sheet of paper to be fed into a nip defined between a first feed roller 70 and an idler roller 72. The first feed roller 70 is con-nected by means of a belt and pulley arrangement to a second feed roller 74. The belt connection can be seen in FIG. 1 wherein a pair of pulleys 76 and 78 are connected by means of a belt 80 such that when the paper transport motor 82 is connected to and rota-tively drives the pulley 78, the pulley 76 is also driven. The pulley 76 is fastened to the same shaft on which the first feed roller 70 is mounted. Simi-o~

larly, the pulley 78 is fastened to the same shaftthat has the second feed roller 74 mounted on it.
As the sheet is fed past the first feed roller 70 and the idler roller 72, a paper guide 82 urges the paper around the first feed roller and onto the easel or viewing screen 30. A pair of ~-configured edge guides 84 located on either side of the viewing screen 30 guide the paper so that it is properly aligned as it is fed up onto the viewing screen 30.
There is a second idler roller 86 which forms a nip with the second feed roller 74 to continue feeding the paper up along the viewing screen 30. When the paper is in its proper image reproduction location, it trips a paper registration sensor arm 86 that ex-tends through an opening 88 in the viewing screen 30.
The sensor arm 86 is connected to a paper registration sensor switch 90 that is connected to the control circuit. When the registration sensor switch 90 is tripped, it causes the paper transport motor 82 to turn off thereby stopping the first and second feed rollers 70 and 74.
During the feeding of the dry silver paper from the cassette, the lamp 18 was deenergized and the cafe doors 36 were closed. This is critical as the dry silver paper is light sensitive and must not be subjected to stray light. When the dry silver paper is in its proper imaging position, the lamp 18 is momentarily energized, projecting the image onto the dry silver paper. After the predetermined imaging time, the lamp 18 is deenergized and the paper trans-port motor 82 is energized. This causes the first and second feed rollers 70 and 74 to drive the paper into a developing station 92.
At the developing station 92 there is a developer motor 94 connected to a developer roller 96 which has a brush fiber surface 98 thereon. Surround-ing the brush surface 98 is a developer shoe 100 tha~

is connected to a power source. The developer shoe 100 is heated to a predetermined temperature to cause the latent image on the dry silver sheet to develop as it is fed between the heater roller 96 and to the developer shoe 100. The development time depends upon the developer shoe temperature and the speed of the heater roller 96. The developed dry silver sheet is ~hen discharged onto a receiving tray 102.
The operation of the reader-printer 10 is controlled by a control circuit illustrated schematic-ally in FIG. 5 and designated as a whole by the re~er-ence character 110. Circuit 110 includes a pair of power supply terminals 112 and 114 adapted to be con-nected as illustrated to a nominal 120-volt alternating current power suppl~ 116. The mode of operation of the control circuit 110 is selected by means of a double-pole, double-throw mode selector switch 118 (FI~S. 1, 2 and 5). Switch 118 is illustrated in its off position with no power supplied to control circuit 110.
For viewing of a microimage projected upon the viewing screen 30, the mode selector switch 118 is operated to a "view" position in which projection lamp 18 is energized at a maximum intensity by the control circuit 110. In the view position of switch 118, contacts 118A are closed to supply power to an illumination control circuit 119 including normally closed timer-controlled contacts 38A and 38B and the primary winding 120 of a voltage reduction transformer 1~2. Contacts 38A and 38B are controlled in the manner described below by the timer motor 38. Transformer 122 includes a secondary winding 124 in circuit with the projection lamp 18, and the transformer 122 pro-vides the proper operating voltage for the lamp 18.
In the illustrated embodiment of the invention, the lamp 18 operates at 13.8 volts.

In order to make a printed copy of the pro-jected microimage, the mode selector switch is moved to an alternate l'print" position in which contacts 118B and 118C are closed. Contacts 118B and 118C
supply power from the power supply terminal 112 to a -printing sequence control network generally designated as 126 while contacts 118C supply power for operation of the timing motor 38 and the illumination control circuit 119 during a print cyc:le.
In addition to rotat:ing the cam ~0 for clos-ing doors 36 durin~ the print cycle, the timer motor 38 also operates an electromechanical timer device including sequence controlled switch contacts 38A, 38B, 38C, 38D and 38E. These contacts are operated respectively by a series of cams 39A, 39B, 39C, 39D
and 39E (FIG. 6) rotated through a timer reduction gear (no~ shown) by the motor 38. In the preferred arrangement, the motor 38 and drive gear aee arranged so that the switch control cams of the timer mechanism complete one revolution in thirty seconds, this being the duration of a print cycle of the reader-printer 10 .
The sequence of operation of the contacts controlled by timer motor 38 is shown graphically in the chart illustrated as FIG. 6 of the drawings. Cams 39A, 39B, 39C, 3~D, 39E and 40 are shown diagrammatic-ally in the home position adjacent corresponding por-tions of a timing sequence chart wherein shaded por-tions represent the closed condition of the timer controlled contacts 38A, 38B, 38C, 38D and 38E.
Many electromechanical timers well known to those skilled in the art may be used for operating the timer controlled contacts in the desired sequence.
The preferred embodiment of the invention makes use of a Singe~ Model 146 electromechanical timer. It should also be understood that features of the inven-tion may be achieved with other types of timing ar-* Trade Mark . ~

rangements~ including but not limited to other types of electromechanical timers, time delay relay con-trolled circuits and circuits controlled electronically as by microprocessors or other logic devices.
When the "print" mode is selected, contacts 118B supply power in the network 126 to an electrical resistance heating element 111 of the developer shoe 100. During the time require~ for the developer shoe 100 to reach its elevated operating temperature, con-tacts 118C continue to supply power to the illuminationcontrol circuit 119 including the projection lamp 118 through a circuit branch 127 so that continued viewing of the projected image on the viewing screen 30 is possible.
The operating temperature of the developer shoe 100 is regulated by a solid state switch, such as, for exa~ple, a triac 128 connected in series with the developer shoe heating resistance element 111.
The triac 128 is controlled by a solid state tempera-ture regulating circuit including a zero-crossing switching network 135 and associated components includ-ing resistors 136 and 137, a variable resistor 138, a capacitor 139 and a temperature sensitive resistive element such as a thermistor 1400 In the illustrated embodiment, the zero-crossing switching network takes the form of a type 3059 integrated circuit manufactured by RCA and other manufacturers, but other switching networks may be used. The thermistor 140 is in heat transfer relationship with the developer shoe 100 and has a resistance that varies as a function of the temperature of the developer shoe 100. The variable resistor 138 provides a temperature adjustment for setting the desired temperature of the developer shoe 100. The network 135 monitors the voltage at the junction of the variable resistor 138 and the thermis-tor 1~0 and applies a gating signal to the triac 128 to trigger the triac 128 whenever the voltage at the ~670~4 junction of the variable resistor 138 and the thermis-tor 140 indicates that the temperature of the developer shoe 100 is too low. The triggering is done during zero crossings of the AC voltage waveform to minimize the generation of transients. The capacitor 139 serves as a filter capacitor for the temperature sensing network. Other electrical, mechanical and electro-mechanical controllers could a]Lso be used. For example, the triac 128 could be replaced with a relay.
Alternatively, the entire temperature control circuit could be replaced by a mechanical switch, such as, for example, a bimetallic strip in contact with the developer shoe 100 that provides a normally closed switch in series with the heating element 111 that opens when the temperatura of the developer shoe 100 reaches the desired temperature.
When the developer shoe 100 reaches the desired operating temperature, normally open bimetal controlled contacts 130 close to enable the beginning of a print cycle~ Contacts 130 are also in heat trans-fer relationship with the developer shoe lU0 and are designed to close at a slightly lower temperature than the contacts 128 to the end that the contacts 130 remain closed during cycling operation of the contacts 128.
When the desired developer operating tempera-ture has been reached and detected by closure of con-tacts 130, a circuit is completed for energization of an indicator lamp 132. As shown in FIGS. 1 and 2, lamp 132 is located at the front of the reader-printer 10 and provLdes an indication that a print cycle can be commenced.
A print cycle is carried out during each single energ:Lzation of the timer motor 38. To initiate a cycle, a manually operated push-button switch 134 (FIGS. 1, 2 and 5) is actuated. This momentarily completes a circuit through the mode selector switch 1~7~)24 contacts 118C and the bimetal controlled contacts 130 for energization of the timer motor 38. When the timer motor 38 begins its cycle of rotation, timer controlled contacts 38C are closed after an interval of a fraction of a second and, as can be seen in FIG.
6, remain closed throughout a ]print cycle until the cycle is completed. At the end of the cycle, contacts 38C reopen to discontinue energization of the timer motor 38 in preparation for thle next subsequent cycle.
Contacts 38C provide an alternate path for energization of the timer motor 38 independent of the print switch 134 and bimetal controlled contacts 130.
Moreover, circuit branch 127 permits timer motor 38 to be energized by way of either contacts 118C or 118A after a cycle of operation begins and contacts 38C close. Thus, each time that a print cycle is initiated, the timer motor 38 is positively controlled to complete one full cycle independent of operation of the mode selector switch 118 to the "view" positionO
20 The cycle is not stopped at any point during its pro-gress and it is not possible for components operated during the print cycle to inadvertently be operated continuously. One advantage of this arrangement is that the components can be rated for intermittent rather than continuous use with a cost saving and without danger of overheating or destruction of the components.
When timer motor 38 is energized first by print switch 134 and therèafter by contacts 38C, the cam ~0 rotates in the manner described above to close the viewing doors 36 and isolate the interior of the reader-printer 10 from ambient light. The sequence of operations then carried out by circuit 110 is con-trolled by the timer-controlled contacts as illustrated in FIG. 6.
As a print cycle commences, the projection lamp 18 is controlled to prevent exposure of a sheet of paper until it is properly positioned and is then controlled to provide a regulated exposure intensity.
Normally closed contacts 38B open near the beginning of a print cycle to prevent energization of the pro-jection lamp 18. Thereafter, normally closed contacts 38A open to enable control o~ the intensity of projec-tion lamp 18. When contacts 38A are openl the circuit for supplying power to the transEormer 122 and lamp 18 includes a variable resistor 136 adjusted by a knob 138 located at the front of the reader-printer 10 (FIGS. 1 and 2). When the dry silver paper sheet is properly positioned for exposure after approximately fourteen seconds, contacts 38B reclose for an exposure interval of approximately three seconds. During this interval, lamp 18 is energi~ed at a selected intensity level by a circuit including the variable resistor 136 and closed contacts 38B. At the end of the expo-sure operation, contacts 38B reopen to discontinue energization of lamp 18, and shortly before the end of the print cycle, the contacts 38A reclose to disable the variable resistor 136 and restore the illumination control circuit 119 for operation at maximum intensityr Contacts 38B close after contacts 38A in preparation for a subsequent viewing operation.
Cassette feed motor 68 is controlled to advance a sheet of paper from the paper tray 34. Dur-ing the print cycle, when projection lamp la is dis-abled by opening of contacts 38B, normally open con-tacts 38E are closed to energize motor 68. As a re-sult, cassette feed rollers 64 advance the topmostsheet toward feed roller 70 and idler roller 72. The normally closed switch 90 in series with contacts 38C
provide a circuit for energi~ing the paper transport motor 82 so that the feed rollers 70 and 74 are rotat-ing. When t:he topmost sheet reaches feed roller 70, it is advanced by rollers 70 and 74 into the exposure position. t'ontacts 38E remain closed for an interval 2 ~7~2 of about four seconds, long enough to advance the top sheet until its leading edge is engaged and further advanced between rollers 70 and 72.
As the paper sheet reaches the proper posi-tion for exposure, its leading edge engages sensor arm 87 and operates paper registration switch 90 from its illustrated closed to its open position. This interrupts the circuit for energization o~ the paper transport motor 82 and feed rollers 70 and 74 stop.
The paper sheet is held stationary in proper position for exposure. While the sheet is stopped, the projec-tion lamp 18 is operated by contacts 38B at a selected intensity level in the manner described above until the exposure operation is completed.
In order to advance the exposed paper sheet to the developing station 92, normally open contacts 38D are closed at the end of the exposure interval and provide an alternate circuit branch for energiza-tion of the paper transport motor 82. Contacts 38D
remain closed for about ten seconds, and feed rollers 70 and 74 advance the paper sheet until its leading edge engages and is further advanced by the heater roller 96 in cooperation with the developer shoe 100.
The developer motor 94 operates continuously whenever the print mode is selected by the mode selection switch 118 to the end that the components of the developing station 92 are uniformly heated by the continuously energized developer heating element 111. After the trailing edge oX the paper leaves the nip of roller 86 and 74, contacts 38D may be reopened since further energization of the motor 82 is not required. The developing process may continue after completion of the timer controlled print sequence.
As the exposed image on the paper sheet moves through the developer station between roller 96 and shoe 100, it is developed by heatO The developed sheet is advanced by roller 96 to the receiving tray ~7a~

102 at the top of the reader-printer 10. As the print cycle is completed, contacts 38C are reopened to stop the timer motor 38 at a home position ready for initia-tion of a further print cycle. If desired, the mode selector switch 118 may be ieft in its "print" posi-tion, and a further print cycle may be initiated by again pressing the print switch 134 to reenergiæe timer motor 38 and begin another complete print cycle.
Alternatively, the mode selection switch 118 may be moved to the illustrated off position or may be re-turned to the "view" position to reclose contacts 118A for further viewing of projected images.
While the invention has been described in eonjunction with a specific embodiment, it is evident that many alternatives, modifieations, and variations will be apparent to those skilled in the art in light of the foregoing deseription. Aeeordingly, it is intended to embrace all such alternatives, modifica-tions and variations as fall within the spirit and broad seope of the appended elaimsD

Claims (19)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A microimage reader-printer comprising:
a housing;
a viewing screen disposed at a fixed location within said housing;
means for projecting images onto said viewing screen, said housing having viewing means for permitting a viewer to view said viewing screen, said viewing means having means for controlling the passage of light therethrough;
means for holding a supply of light sensitive sheets;
a developing station;
means for transporting said light sensitive sheets individually from said supply holding means onto the surface of said fixed viewing screen for exposure by said projecting means and to said developing station; and control means responsive to a print signal for sequentially rendering said projecting means operative to disable said lamp means, operating said transporting means to transport one of said sheets from said holding means onto said fixed viewing screen, rendering said projecting means operative to enable said lamp means to project an image onto the sheet present on the fixed viewing screen to expose said sheet, rendering said projecting means operative to disable said lamp means, operating said transporting means to transport said sheet to said developing station for development, and rendering said projecting means operative to enable said lamp means to project an image onto the viewing screen.

2. A microimage reader-printer as recited in claim 1 wherein said projecting means is a front projection projecting means.

3. A microimage reader-printer as recited in claim 1 wherein said control means includes a timer motor, a plurality of cams operated by said timer motor and a plurality of switches that are sequentially activated by the cams.

4. A microimage reader-printer as recited in claim 3 wherein said means for controlling the passage of light through said viewing means includes a door.

5. A microimage reader-printer as recited in claim 4 further including means for opening and closing said door, and linkage means including a door operating cam and a cam follower operatively connected between said door operating cam and said door for selectively opening and closing said door.

6. A microimage reader-printer as recited in claim 5 wherein said door operating cam is operated by said timer motor.

7. A control circuit for apparatus for reading or printing images from a microimage record comprising:
a control switch for selecting a view mode or a print mode;
a print switch for initiating a copy print sequence;
a first circuit energized by operation of said control switch to the view mode for projecting a viewable image of the microimage record;
a second circuit energized by operation of said control switch to the print mode and operation of said print switch for carrying out a copy print sequence;
sequence timer means in said second circuit energized by operation of said print switch for controlling a timer cycle including copy feed, exposure and developer operations; and a circuit branch connected between said first and second circuits for maintaining operation of said sequence timer means during a timer cycle in response to operation of said control switch from the print mode to the view mode prior to completion of the timer cycle.

8. A control circuit as claimed in claim 7, said second circuit including a developer heater and means for delaying operation of said sequence timer means after energization of said developer heater.

9. In a reader-printer for viewing a projected image from microfiche and selectively producing paper copies of the images, a combination comprising:
a housing with an image viewing opening;
an optical system having a lamp projecting the microfiche image through a lens onto a fixed mirror in the housing which reflects the image onto a fixed front projection screen in the housing, the image being projected from the screen outwardly through the viewing opening;
microfiche retaining means for selectively positioning the microfiche;
an image copying system including:
a cassette retaining sheets of dry silver paper;
means for feeding a sheet from the cassette onto the projection screen and stopping the sheet when it is positioned in an imaging position wherein an image from the fiche is directed onto the sheet;
means for closing the viewing opening to ambient light to enable the image to be projected onto the sheet of dry silver paper forming a latent image thereon after the sheet is in the imaging position;
means for developing the latent image on the sheet;
means for feeding the developed sheet from the housing;
control means to control the sequence of operation of the means for feeding a sheet, the means for closing the viewing opening, the means for projecting the image to form the latent image and the means for feeding the developed sheet, so that each operation occurs at its predetermined time in the image copying system; and the means for closing the viewing opening being operated in response to initiation of the image copying system and comprising a pair of doors that pivot to close the viewing opening, a mechanical linkage system connected to the pair of doors, a cam operatively connected to the linkage system and rotated by means of a motor, the cam rotating a single revolution in a single printing cycle, and the control means controlling the single revolution.

10. The printer-reader of claim 9 and further comprising means in the housing to removably receive the cassette.

11. The reader-printer of claim 9 wherein the means for feeding a sheet from the cassette comprises a motor driven cassette feed roller operated responsive to the closing of a switch in the control means, the cassette feed roller feeding the top sheet of dry silver paper from the cassette to feed rollers that convey the sheet to the imaging position on the projection screen where the image is projected onto the sheet.

12. The reader-printer of claim 11 and further comprising a paper registration switch that is activated responsive to the paper being fed onto the viewing screen and causes the feed rollers to stop feeding the sheet when the sheet is in the imaging position.

13 The reader-printer of claim 11 wherein the control means causes the feed rollers to begin feeding the sheet from the imaging position after the image is projected onto the sheet for a predetermined time.

14. The reader-printer of claim 11 wherein the control means causes the lamp projecting the image to be deenergized while the sheet is being fed and the lamp to be energized for a predetermined time while the sheet is stationary on the projection screen.

15. The reader-printer of claim 9 wherein said developing means includes:
a developer shoe;
a roller disposed adjacent said shoe to define a sheet developing path therebetween; and means for transferring heat to said develop-ing path to develop a latent image as a sheet is moved therethrough.

16 The reader-printer of claim 15 wherein the means for feeding the developed sheet from the housing is the heater roller.

17. The reader-printer of claim 11 and further comprising paper edge guides on the projection screen to guide the sheet along the screen as it is being fed by the feed rollers.

18. The reader-printer of claim 9 and further comprising voltage control means to vary the illumination intensity of the lamp when the lamp is used to project the image onto the sheet thereby ef-fecting the contrast and darkness of the developed image.

19. A microfiche reader-printer comprising in combination:
a housing having a projection screen on which an image on the microfiche is projected, the projection screen acting as a viewing surface and an imaging station;
an image viewing opening in the housing through which the image is projected for viewing;
an optical projection system comprising a lamp for projecting the image through a lens system to a fixed mirror in the housing which reflects the image onto the projection screen;
a cassette retaining unexposed sheets of dry silver paper;
a cassette feed roller engaging the top sheet of paper in the cassette to feed the top sheet to feed rollers that convey the sheet onto the projec-tion screen;
switch means operative to stop feeding of a sheet when the sheet is received on said imaging sta-tion;
a pair of doors that pivot to close the viewing opening during imaging, a cam and follower connected to a mechanical linkage which is connected to the pair of doors, the cam rotating a single revolu-tion in an imaging cycle to close the doors during imaging and reopen them after imaging;
a control means to deenergize the lamp while the sheet is being fed to the imaging station, energiz-ing the lamp for a predetermined time while the sheet is stationary at the imaging station causing a latent image to be formed on the sheet, and deenergizing the lamp while the sheet is transported from the imaging station to a developing station;
the developing station including a roller and shoe defining a path to receive the sheet after imaging, and a source of heat to develop the latent image on the sheet;
means for driving the roller to discharge the sheet outside of the housing after the image is developed.

The reader-printer of claim 19 wherein the control means includes a motor-operated series of timers and switches that control the cam and door opening and closing mechanical linkage, the sheet feeding to and from the imaging station and energiza-tion and deenergization of the lamp.