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Publication numberUS3815992 A
Publication typeGrant
Publication dateJun 11, 1974
Filing dateJun 30, 1972
Priority dateOct 30, 1969
Publication numberUS 3815992 A, US 3815992A, US-A-3815992, US3815992 A, US3815992A
InventorsOgawa M
Original AssigneeMinolta Camera Kk
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Projection type duplicator
US 3815992 A
Abstract
In a projection type duplicating apparatus the lighting energy of the light source is controlled in accordance with the magnification of the projecting lens system by a number of control circuits and a control switch is actuated by the proper positioning of the photosensitive means within the image receiving position. The circuit for controlling the energy of the light source includes a capacitor connected in series with the control switch and a relay actuated by the discharge of that capacitor for energizing the light source. In an alternative embodiment the control circuits each comprise a portion of the primary winding of a transformer, the secondary winding of the transformer being connected across an additional capacitor whereby the charging voltage of the additional capacitor is controlled by the transformer.
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Description  (OCR text may contain errors)

United States Patent [1 1 [111 3,815,992 Ogawa June 11, 1974 PROJECTION TYPE DUPLICATOR 3,052,156 9/1962 Blatherwick 355/69 3,227,039 l/l966 5' mo 355/69 [75] Inventor: Masaya ogawa Osaka Japan 3,467,469 9/1969 ri in et al. 355/67 [73] Assignee: Minolta Camera Kabushiki Kaisha,

Osaka, Japan Primary Examiner-Samuel S. Matthews Assistant Examiner-Russell E. Adams, Jr. [22] Flled' June 1972 Attorney, Agent, or Firm-Wats0n, Cole, Grindle and [21] Appl. N0.: 268,123 Watson Related U.S. Application Data [63] Continuation of Ser. No. 872,548, Oct. 30, i969, [57] ABSTRACT abandoned. The present invention relates to a pro ection type duplicator and more particularly, in a duplicator changa- [52] U.S. Cl. 355/69, 355/67 bio of the gni i n a proje ion ype uplicator [51] Int. Cl. G03b 27/54, G03b 27/72 n which h quantity f ight f radiation from a light [58] Field of Search 355/67, 69 o rce for lighting up a manuscript is set up corresponding to the magnification and although the magni- [56] Refere s Cited fication is changed the proper exposure for a photo- UNITED STATES PATENTS sensitive paper iS radiated.

2,561,535 7/l95l Paulet et al 355/69 3 Claims, 7 Drawing Figures PATENTEDJUN 1 1 1914 3.815992 saw an! 4 PAT-ENTEMMHHM 4 v sis-15199 2 manor 4 PROJECTION TYPE DUPLICATOR This is a continuation of application Ser. -No. 872,548, filed Oct. 30,1969, now abandoned. v

BACKGROUND OF THE INVENTION A projection type duplicator has an advantage in permitting the magnification of duplication thereof to change, however, when the magnification is changed keeping the brightness of a light source constant, the lightness of image of the manuscript projected is changed in inverse proportion to a square of the magnification plus 1.

When duplicating by using a projected image, therefore, it is necessary to change the lightness of the projection image in accordance with the magnification or to change the exposure time of the photosensitive paper. For this purpose, in the prior art it has been necessary to provide a diaphragm for a projection lens for duplication or to restrict the exposure time in accordance with the intensity of illumination on the image forming surface of the manuscript, or to control the flow speed in a flow type duplicator.

However, when the contrast of the manuscript is nearly fixed, making use of such steps complicates the mechanism of the duplicator to no purpose.

SUMMARY OFTHE INVENTION The present invention relates to a projection type dg plicator which is not provided separately with a diaphragm, timer, and other parts for adjusting the exposure and yet controls the quantity of light of radiation from a light source in accordance with the magnification set up for a lens through the lighting time or the brightness of radiation, by interlocking a member for setting up the magnification with a duplication lens changeable in accordance with the magnification, such a member may comprise an adjusting member for different lens positions or a transmitting member for the lens magnification, together with an electrical element for controlling the quantity of light of radiation from a light source.

The primary object of the present invention is to provide apparatus for keeping the exposure of a photosensitive paper for duplication constant by controlling the quantity of light radiation from a light source in accordance with the magnification set up for a duplication lens.

The second object of the present invention is to eliminate a diaphragm in a lens system, a shutter, and a photometer and a control device for controlling a shutter or the lighting time of the light source by receiving light of the intensity of illumination for forming an image of the manuscript by, except for controlling radiation given by a light source.

The third object of the present invention is to provide apparatus for changing the lighting time of a light source for giving light in a fixed brightness in ac-- cordance with the magnification set up for a duplicator.

The fourth object of the present invention is to provide apparatus for changing the brightness of a light-source lighting for a given period of time in accordance with magnification set up for a duplicator.

The fifth object of the present invention is to provide apparatus for controlling the quantity of light radiation from a light source in accordance with the focal distance adjustment of a lens for duplication, in a modification changeable duplicator in which the interval between a manuscript and a photosensitive paper is kept nearly constant.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of an embodiment illustrating the relationship between the lighting time of a light source with the magnification set up for a duplication lens in accordance with the present invention.

FIG. 2 is a circuit diagram ofthe timer ofthe same embodiment as in FIG. 1.

' FIG. 3 is a side view ofthe second embodiment of the present invention.

FIG. 4 is a circuit diagram of the timer of the same embodiment as in FIG. 3.

FIG. 5 is a side view of the third embodiment using a flash discharge tube as a lighting source and relationship between the brightness of radiation with the magnification set for a duplication lens in accordance with the present invention.

FIG. 6 is a circuit diagram for controlling the brightness of radiation in the same embodiment as in FIG. 5.

FIG. 7 is a side view of the fourth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the first embodiment shown in FIGS. 1 and-2 in accordance with the present invention, manuscript 1 is held on manuscript holding glass base 2 and lighted by light source 4, and its image is projected by duplication lens system 3.

Photosensitive paper 6 is held between driving transmission rollers 10,, I0 interlocked by motor 8 and belt 9, and rollers 11,, 11 pressed respectively to contact with rollers 10,, 10 so as to be transmitted from the left to the right in FIG. 1, and meanwhile charged by charging devices 13, 13. Photosensitive paper 6 is placed on belt 7 mounted over driving transmission roller 10 and transmission roller 10 Photosensitive paper 6 is stopped at the image forming position at duplication lens system 3 for manuscript 1 to receive the exposure from light source 4 lighted at that time and transmitted again by belt 7 after light source 4 is extinguished. Photosensitive paper is transferred onto belt 7 mounted over roller 10., interlocked by transmission roller 10 and belt 9 to be delivered to the developing section not shown in the figures.

Within the range where duplication lenssystern 3 moves in accordance with the magnification there are provided a plurality of switches (3 switches shown in FIG. 2) 12,, 12 12 so as to be closed by working member 5 of the lens barrel corresponding to the up and down movement of lens system 3. That is, ordinarily opened switches 12 12 12 are adapted to close by means of working member 5. As shown in figures in the equivalent magnification condition switch 12 is closed, for example, when the magnification is decreased one half switch 12 is closed and when the magnification is increased two times switch tiss ssti.

Next, with reference to the circuit diagram shown in FIG. 2, between terminals A and B connected to a power source microswitch l4 and condenser 15 are connected in series. In FIG. 2, when the front end of a photosensitive paper 6 moves past microswitch 14 the actuator thereof is operated to come into contact with contact 14a and capacitor 15 is charged, and when the trailing end of photosensitive paper 6 moves past the actuator turns over to come into contact 14b and the voltage charged in condenser 15 is impressed on the base of transistor 17 through neon tube 16 to make transistor 17 conductive. The collector circuit of transistor 17, includes coil 19 of relay 18. And, coil 19 is connected to the emitter through condenser 20 and to the electrode on the opposite side thereof through rectifier 21. Ordinarily closed contact 18a of relay 18 connects motor 8 to the power source, and contact 1812 is connected to light source 4. M

B etween cont act 14b of microswitch l4 and neon tube 16 there are connected resistors 22,, 22 22 respectively through switches 12,, 12 12 switched by means of working member 5 of the lens barrel of lens 3 in parallel through variable set resistance 23.

Therefore, when lens 3 is set in the position shown in FIG. 1 in order to duplicate in the equivalent magnification, switch 12 is closed by working member 5 and switches 12,, 12 are left open. In this situation the relay is in contact with contact 18a and the circuit of motor 8 is closed and accordingly driving transmission rollers 10,, 10 are running. Thereby, a photosensitive paper inserted from the left side is transmitted to the right, in turn charged by charging devices l3, 13. The photosensitive paper is put on belt 7, to be carried by belt 7,, and thus,when the front end of photosensitive paper 6 comes to the position of the actuator of microswitch 14, microswitch 14 is changed over to contact 14a and capacitor 15 is charged. Motor 8 continues to rotate so s. to y. ,phqt ens tiwwaaq 6 to the image forming position in the equivalent magnification by duplication lens system 3 for manuscript 1. At this juncture. the trailing end of photosensitive paper 6 stops pressing the actuator of microswitch 14, so that microswitch is changed over to contact 14b,

a h lt char n capaqitsar .5 is r s ed,

on the base of transistor 17 by discharging neon tube 16 to make transistor 17 conductive to excite coil 19 in the collector circuit. Thereby relay 18 is changed from contact 18a to contact 18b to break the circuit of motor 8 and at last to close the circuit of light source 4. At the same time the voltage charged in capacitor 15 starts to discharge through variable set resistance 23, switch 12 and resistance 22 Upon receiving the proper quantity of the exposure of manuscript 1 lighted up with the given brightness by turning on light source 4, the voltage in capacitor 15 drops due to the above-mentioned discharge and the discharge of neon tube 16 is stopped to the cutoff condition due to the voltage drop in the base of transistor 17. Coil 19 is deenergized so that relay 18 changes over again to contact 18a, the light source extinguished, and motor 8 starts again to rotate so as to carry exposed photosensitive paper6 by means flows through variable set resistance 23 and resistance 22,, so that by setting up the respective resistance so that the time to the stoppage of discharge of neon tube 16 may be 9/4 times as much as the previous time it is possible to obtain automatically the proper exposure also in this case. Also, by adjusting variable set resistance 23 it is possible to compensate for the fluctuation of the manuscript contrast or the sensitivity of the photosensitive paper.

In the second embodiment shown in FIG. 3 and FIG. 4, for changing over resistances 22,, 22 23 by means of switches 12,, 12 12 working member 5 of lens barrel is formed into a brush, and variable resistance 22 is provided on which the brush slides. And also in the circuit instead of switches 12,, 12 12,, and resistances 22,, 22 23 in parallel with each other one slidable and variable resistance 22 is inserted in series with variable set resistance 23 so as to allow the light source to radiate the proper quantity of light of radiation corresponding to the continuous change of the duplication magnification. Such a type of light source has an advantage in a flow type duplicator which provides exposure while moving a photosensitive paper and a light source or a manuscript in parallel with each other and at a fixed speed ratio.

In the third embodiment shown in FIG. 5 and FIG. 6, the brightness of radiation of a light source is changablc corresponding to the duplication magnification. and a switch mechanism switched by means of working member 5 and a mechanism for feeding photosensitive papers by means of motor 8 are the same as those in the first embodiment and the same symbols are used to denote the same parts.

Primary circuit 24a of transformer 24 connected to terminals A, B of a power source is so constructed that a portion thereof is short-circuited by opening and closing switches 12' 12,. That is. when the duplication magnification is changed in the following sequence magnification equivalent magnificationcontraction, the number of turns of primary winding 2992f ttaai rt sr 251$ .s s s follows ma l middle large, and the voltage generated in second ary wit d nazslz thsxe f s sh ns as follows large middle small. The voltage is charged in capacitor 25 and the actuator of microswitch 14 is changed over to contact 14a by-the passing of photosensitive paper 6. Capacitor 15 is charged by the power current, photosensitive paper 6 moves past the actuator and comes to the position just under duplication lens 3, and at this juncture the actuator of microswitch 14 returns again to contact 14b. The photoelectric. current of capacitor 15 flows through coil 19 of relay 18 to close the relay switch. On trigger electggle gq 9f flash dischargetube 4 a trigger pulse is impressed, the electric charge in capacitor 25 is discharged through discharge tube 4, and discharge tube 4 instantaneously turns on a light.

And, the brightness of radiation is changed in accordance with the quantity of energy charged in capacitor 25. Provided the capacity of capacitor 25 is C and the voltage charged is V. the quantity of energy E charged therein is shown as follows:

E '6 CV In the fourth embodiment shown in FIG. 7, slidable 9352,55?,is r viqs o Primary winding of transformer 24 so as to interlock 5" with displacement of duplication lens 3 in the duplicator, and the voltage charged in capacitor 25 is made changeable continuously in accordance with the magnification of duplication. The intensity ofillumination of an image formed on the photosensitive paper of manuscript 1 irradiated by a light source in any magnification is made continuously invariable.

In the above-mentioned third and fourth embodiments, when a flash discharge tube the lighting time of which is momentary and can not be controlled is used as a light source for the duplicator the brightness f ad a ion 9 be 9Qmr9 Q fia fi t i of great advantage to the duplicator making use of such a kind of light source, and in such a kind it is possible to expose while transmitting the photosensitive paper without stopping it, therefore, there is no need of controlling the running and stopping of driving motor 8.

I claim:

1. A projection type duplicating apparatus, comprismg:

a transparent member mounted to said apparatus for positioning source material to be duplicated;

means for transporting photosenstiive means along a path spaced from said transparent member and including an image receiving position;

a flash discharge light source for providing radiant energy to said source material on said transparent member;

a projecting lens system movable between said transparent member and said image receiving position for projecting an image of said source material to said photosensitive means at said image receiving position in accordance with a desired magnification;

a number of switches positioned in spaced relationship with respect to said optical axis and individually actuated by said movable projecting lens system in accordance with said desired magnification;

a number of control circuits, each one of said control circuits is connected to a respective one of said switches for controlling the lighting energy of said light source in proportion to the square of the quantity represented by said magnification plus one;

a control switch mounted along said path in a posi tion whereby said photosensitive means engages said control switch before reaching said image receiving position, said control switch having a first position and a second position, said control switch is in said first position with said photosensitive means entering said image receiving position and in said second position with said photosensitive means at said image receiving position; and

a circuit for controlling the energy of said light source and including a first capacitor connected in series with said control switch and a relay actuated by the discharging of said first capacitor for energizing said light source upon arrival of said photosensitive member at said image receiving position,

said first capacitor is connected to said power source and with said control switch in said first position said first capacitor is connected to said selected one of said control circuits for discharging said first capacitor with said control switch in said second position, and said relay energizing said means for transporting after completion of an exposure to remove said photosensitive means from said image receiving position.

2. A projection type duplicating apparatus as in claim 1 wherein said number of control circuits each include a resistance and a variable resistance connected therewith.

3. A projection type duplicating apparatus as in claim 1 wherein said light source further includes a second capacitor for energizing said light source and wherein said control circuits each comprise a portion of the primary winding of a transformer, said transformer having a secondary winding connected across said second capacitor, said transformer controlling the charging voltage of said second capacitor.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Pateht No. 3,815,992 Dated June 11, 1974 Inventor) Mas aya Ogawa It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[30] Foreign Application Priority Nov. 17, 1968 Japan Utility Model 100037/1968 Signed and sealed this 6th day of May 1975.

(SEAL) Attest:

RUTH C. MASON Arresting Officer C. MARSHALL DANN Commissioner of Patents and Trademarks USCOMM-DC 6037 64 69 FORM PO-IOSO (10-69) u.s. GOVIRNIIENT rnnmuc omcz no o-ssa-au,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Pateht No. 328159992 Dated June. 11, 1974 Inventor S) Mas aya Ogawa It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[30] Foreign Application Priority Nov. 17, 1968 Japan Utility Model 100036/1968 Nov. 17, 1968 Japan Utility Model 100037/1968 Signed and sealed this 6th day of May 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks USCOMM-DC 60376-F69 F ORM PO-l 050 (10-69) u.s. aovnnunrr nmmus omc: ml o-su-au

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2561535 *Dec 5, 1947Jul 24, 1951Paulet Armand RPhotographic light control
US3052156 *Dec 11, 1958Sep 4, 1962W A Brown Mfg CoProjection copy camera assembly
US3227039 *Jul 16, 1963Jan 4, 1966Simmon Brothers IncDensity control for photographic enlargers
US3467469 *Oct 17, 1966Sep 16, 1969Dennison Mfg CoCover for photocopiers
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3898006 *Aug 27, 1974Aug 5, 1975Canon KkExposure lamp control device
US4046475 *Feb 3, 1976Sep 6, 1977Addressograph Multigraph CorporationExposure control system for photocomposition machines
US4066351 *Feb 20, 1976Jan 3, 1978Xerox CorporationVariable illumination optical system
US4095895 *Aug 26, 1976Jun 20, 1978Oce-Van Der Grinten N.V.Method and means for preventing edge shadow effects during episcopic exposure of an original
US4193679 *Aug 23, 1977Mar 18, 1980Ricoh Company, Ltd.Electrophotographic apparatus comprising improved imaging system
US4278334 *Nov 26, 1979Jul 14, 1981Minolta Camera Kabushiki KaishaIllumination control apparatus for projection device
US4794422 *Nov 27, 1987Dec 27, 1988Xerox CorporationElectrophotographic reproduction machine with document exposure system directly coupled to ac line input
Classifications
U.S. Classification355/69, 355/67
International ClassificationG03G15/041
Cooperative ClassificationG03G15/041
European ClassificationG03G15/041