US3121381A - Photocopy exposure machine - Google Patents

Description

Feb. 18, 1964 A, sANDMElER PHoTocoPY EXPOSURE MACHINE 2 Sheets-Sheet 1 Filed Feb. 5, 1962 665 "uw 66a 72 vpn".

o EYs ATT Feb. 18, 1964 A. sANDMElER 3,121,381

i PHOTOCOPY EXPOSURE MACHINE zzz 0 INVENTOR TTO EYS United States Patent 3,121,381 PHQTGCOIY EXPSURE MACHINE Arthur Sandrneier, Babylon, NX., assigner to Copease Corporation, New York, NX., a corporation of Delaware Filed Feb. 5, 1962, Ser. No. 170,906 1 Claim. (Cl. 95-73) This invention relates to machines for making photocopies, for example according to the diffusion-transferreversal process, as disclosed in French Patent No. 879,- 995, issued December 10, 1942, to I. G. Farbenindustrie A G. (Agfa), and particularly to an improved exposure mechanism incorporating a novel arrangement for varying the degree of exposure of the negative sheet.

As will be understood, since it may be required to copy many diierent kinds of originals and since many different kinds of negative paper may be employed in the machines, it is necessary to provide means for varying the degree of exposure. In the past, numerous ways of varying exposure have been provided, such as rheostats to control the speed of the drive motor and thereby the length of time required for the sheets to pass through the exposure area, adjustable masks to vary the physical length of the exposure area and so forth. All of these previous systems have been complicated, expensive and in most cases susceptible to malfunction. It is therefore among the objects of the present invention to provide an improved arrangement for varying the exposure which is simple in construction, foolproof in operation and susceptible of very inexpensive construction.

In general terms, in the exposure apparatus of the present invention, the light source is mounted on a pivoted support and is moved physically toward or away from the original and photosensitive sheets to vary the exposure. This not only provides a thoroughly reliable system involving no rheostats or other variable electrical circuitry, and no movable masks or variable apertures for controlling the exposure, but also provides an extremely inexpensive system which enables substantial reduction in the manufacturing costs and selling prices of photocopying machines.

In the drawings:

FIGURE l is a front quarter perspective view of a complete photocopy exposure and developing machine embodying features of the present invention, this illustrative machine being particularly designed for use in the practice of the diffusion-transfer-reversal process,

FIGURE 2 is an enlarged cross-sectional view taken through the central portion of the machine as generally indicated by the line 2-2 in FIGURE 1.

FIGURE 3 is a staggered fragmentary sectional view taken along the offset line 3-3 of FIGURE 2.

FIGURE 4 is a cross-sectional view taken on the line 4-4 of FIGURE 3.

FIGURE 5 is a perspective view of the movable mount for the light source, shown separately from the remainder of the machine for purposes of clarity.

As may be seen in FIGURE l, the entire machine is housed in a composite housing lil formed by a removable top portion 12 and a base portion 14. The exposure section, generally designated 16, is contained in the upper portion of the housing 10, while the developing portion, generally designated 18, is contained in the lower portion.

As may be seen in FIGURES 2 and 3, the mechanism of the exposure section 16 is mounted on side frame 20 which are secured to and project upwardly from the bottom of the base portion 14 of the cabinet. As may be seen in FIGURES 2 and 4, an irregularly shaped sheet support member generally designated 22, which is formed of a transparent plastic material such as Lucite, extends between the two side frames Ztl and is supported on them haunted Feb. 1s, 19e4 ICC by means of pins 22a which are integrally molded with the support 22 and project through holes in the side frames Ztl, as best shown in FIGURE 4.

As best shown in FIGURE 2, the central portion 22h of the sheet support 22 is at and horizontally oriented, and its forward portion is bent downwardly to form a skirt 22e which extends across and covers an opening 12a (see also FIGURE 1) formed in the front of the upper portion 12 of the housing.

As shown in FIGURE 4, the portions 22d and 22e at the front and rear of the sheet support 22 may be painted or otherwise rendered opaque, leaving in the center a transparent area 22f which extends the full width of the support. The central portion of this transparent area 22j is of uniform width (measured in a fore-and-aft direction), while its end portions may be flared as shown at 22g, for a purpose described hereinafter.

The sheet support 22 is provided with two rows of slots 22h and 221', which are provided to receive four narrow drive wheels 24 (see also FIGURE 3) which are tipped with neoprene or a similar resilient material and fixed on a front drive shaft 26 which extends between and is rotatably journalled in the side frames 20. As shown in FIGURES 2 and 3, the drive wheels 24 project a short distance beyond the upper surface of the sheet support 22 and engage a front idler roller 28 which also extends between and is journalled in the side frames 2t?. As shown in FIGURE 4, a similar row of slots 221' is provided in the rear portion of the sheet support 22 to receive a similar set of rear drive wheels 30 (FIGURE 2) fixed on a rear drive shaft 32 and projecting through the slots a short distance beyond the upper surface of the support 22 to engage a rear idler roller 34.

As shown in FIGURE 3, the front and rear drive shafts 26 and 32 are driven by means of an electric motor 35 supported on the base 14 through a pulley 37 on the motor shaft, a belt 39 and pulleys 41 fixed on the projecting end of each of the two drive shafts 26 and 32. The front and rear idler rollers 2S and 34 are driven by frictional engagement with their respective drive wheels 24 and 3? when no sheets are being fed through the machine, or by frictional engagement with the sheets, which are in turn driven by the drive wheels.

As may be seen in FIGURE 2, located centrally between the front and rear idler rollers 28 and 34 is a presser foot, generally designated 36, which consists of a sheet metal body member having a curved base portion 38a which extends substantially the full width of the space between the side frames 20, with ears 3811 at each end which are slidably received and guided in vertical slots Zlla in the side frames 2t). Mounted at the lower surface of the foot portion 38a is a cushion 4t) of resilient material, such as foam rubber or Styrofoam, which is covered with a pile material, such as mohair, which not only covers the lower surface of the cushion 40 and foot portion 38a but also is preferably bent up and around to cover at least their front edges. Elongated coil springs (not shown) extend over the vertically movable bearings at each end of the rollers 28 and 34 and over the upper ends of the ears 38b of the body 38, with the ends of each spring being secured to the side frames 20 at points below the bearings and with the springs under slight tension to urge the idler rollers 28 and 34 into yieldable frictional engagement with the respective sets of drive wheels 24 and 30 and also urge the presser foot 36 yieldably down against the upper surface of the sheet support 22.

Mounted beneath the transparent central portion of the sheet support 22, directly opposite the pressure foot 36, is a fluorescent light bulb 44 which extends transversely of the machine with its end portions projecting through slots 2tlb in the side frames 2t). The bulb 44 is mounted on a reflector bracket 46 which is secured at one end of a light support 4S which is pivotally mounted on pins Si) (see also FIGURE 5) projecting outwardly from tabs 43a depending from the opposite edges of the light. support 48, the pins 50 being journalled in the side frame-s 20. Thus, the light support 48 may be rocked between an ero treme upper position, in which it is shown in tfull lines in FIGURE 2, and an extreme `lower position, in which it is shown in broken lines in that FIGURE.

Since the pivotal axis of the pins 5d is spaced in la generally horizontal direction from the fluorescent bulb 44, this rocking movement causes the uorescent bulb to move generally vertically toward and `away from the sheet support Z2. The weight of the bulb 44, sheet support 48 and associated parts normally urges the bulb 44 iand the rear or right-hand end of the lighty support 48 downwardly toward their extreme lower positions, in which they are shown in broken lines in FIGURE 2. However, down ward movement of the bulb 44 and light support 48 is limited by engagement of a stop pin 5'2 with an inclined cam surface 48b (see also FIGURE 5) formed at the upper edge of an arcuate flange 43C which is bent upwardly from the front or left-hand end of the light support 4S.

The stop pin 52 is secured to and extends inwardly from a control knob 54 which, as shown in FIGURES l and 2, projects from the front of the machine through the opening .12a in the upper portion I2 of the housing. The stop pin 52 projects through an elongated, horizontal guide slot 22 j formed in the skirt 22C of the sheet support 22 and, as shown in FIGURE 2, is secured against withdrawal from the plate 22 by a washer 56 and `a split retaining ring 58 received in a `circumferential slot in the stop pin 52.

As will be understood, `as the knob 54 and pin 52 are moved transversely of the machine `along the Aslot 22j, the stop pin 52 engages the inclined cam surface 48b (FIG- UR'E 5) at different positions along its length. During such movement, the left-hand end of the light support 48, to which the flange 48C is integrally attached, is either pressed furthe-r downwardly 'or permitted to move upwardly, while the opposite, right-hand end of the light support 4S and the bulb 44 thereon are rocked in the opposite direction, .thus moving the bulb 44 toward or away from the sheet support 22. As may be seen in FIGURE 1, the outer face of the skirt 22C just above the slot 22j is provided with a graduated and numbered scale 22k to assist in positioning the Iknob 54 )and accordingly the bulb 44 (FIGURE 2) at the desired position.

In operation, the original sheet to be copied, and the photosensitive negative sheet are inserted into the machine in face-torace relation, with the negative sheet below land with its emulsion facing upwardly in face-to-face contact with the copy side of the original. The two sheets are inserted through an input opening 60 (FIGURES 1 and 2) formed between the upper edge of the opening 12a and the upper surface of the sheet support 22. The iiat central portion 22h of the sheet support 22, projects forwardly some distance beyond the upper edge of the open ing 12a to serve Vas a supporting platform or guide which facilitates vertical positioning of the sheets for feeding into the machine.

The sheets lare pushed manually into the machine to the point where their leading edges reach the bite or point of tangency tof the front drive wheels 24 and fron-t idler roller 28, whereupon the sheets are frictionally gripped between `the drive wheels 24 `and idler roller 28 and driven further along the upper surface of the sheet support 22b and between it and the upwardly inclined forward edge of the pressure foot 36. The spring-biased presser foot 316i, with its soft, resilient cushion 40 and pile surface 42, pres-ses the two sheets into intimate face-toface contact with one another and into intimate contact with the upper surface of the sheet support 22, but without imposing suiiicient resistance to feeding of the sheets to cause buckling, wrinkling or slippage of the sheets. As the two sheets pass over the transparent central portion 22]t of the support 22 (see FIGURE 4) light from the fluorescent bulb 44 passing through this transparent por.- tion 22f exposes the negative to form in it a latent image of the original.

The flared end portions 22g of the transparent center section 22j (FIGURE 4) of the sheet support 22 cause the end portions of the sheets adjacent the side frames 20. to be subjected to the exposing elIect of the bulb 44 over a greater fore-enduit distance during their transit through the machine, and therefore cause them to be exposed for a greater time than the portions of the sheets which pass through the uniformly wide central portion of the transparent area 22j. This compensates for the fact that the amount of light reaching the sheets from the bulb 44 is ydiminished near ecah end of the bulb.

As the sheets move further into the machine, their leading edges pass between the second set of drive Wheels 30 and the idler roller- 34 and are gripped by them and fed further along the upwardly curved right-hand end portion 221 of the sheet support 22` and out of the machine through an exit opening 62 formed between the upper Surface of the right-hand end portion 221 of the support 22 and the upper edge 64a of an opening 64 formed in the rear side of the upper portion I2 of the housing 10.

As may be shown in FIGURE 2, light entering the housing Iii through the opening 64 is blocked from directly impinging upon the sheets `as they pass across the transparental central portion of the sheet support 22 by means of `a rear light shield 66 formed, for example, of lig-ht gauge sheet metal. The shield 6d extends the full width of the space `between the side plates 2b', and is supported between a pair oi closely spaced, transversely extending upper rods i68 and '76, while its lower end is supported on a lower transverse rod '72, 'all .of the rods 6?, 70' and 72 extending between and being secured to the side frames- Zti. The lower end of the plate 62 is provided with a detent groove 66a 'and a beveled lip 66b. As wiii be understood, the light shield l66 may be removed by resiliently bending the lip 66h upwardly to disengage the groove 66a from the lower rod 72 and permit the lower end of the shield I66 to be swung to the right, as viewedV inV FIGURE 2, to the point where the shield can drop downwardly to disengage its upper end from between the rods 6h and 70. When the shield is replaced, the beveled lip 66!) is cammed over the lower rod 72 to the point where the rod 72 can enter the groove 66a.

Light entering the front portion of the machine through the opening 12a and the transparent lower portion of the skirt 22C is similarly blocked by a front shield 74 which is secured `at its lower end to the light support 48 and which projects upwardly therefrom behind the transparent portion of the skirt 22C.

rIhus, in practical effect, the only light impinging upon the negative and original sheets during their passage through the exposure portion 16 of the machine that emanating from the iluorescent buib 44. As wili be understood, the degree of exposure of fthe negative is dependent upon the spacing of the fluorescent buiib 44 from the negative and original sheets during the exposure. As la first order approximation, the intensity of Ilighrt impinging upon the negative and original is inversely proportional to the square lof the distance of the adjacent surface of the bulb from the sheets at the time of exposure. In an arrangement of the type disclosed, it is practical to vary this `distance from a smalll fraction of an inoh up to 3 inches or more. Thus, the exposure may ybe varied over 'the entire range between maximum and minimum values having a ratio lon the order 'of 25 to l.

Since 'the developing portion 18 (FIGURE 1) in the lower portion of the housing 10 forms no part of the present invention, it need not be described here. Suiiice it merely to say that it includes a developing tank 76 having integrally ormed in it lower lguide surfaces 76a, an upper guide 73, a separator pirate 80 and la pair of rollers 82 and 84. The construction and operation of developing devices of Ithis general 'type 'are described more fully in U.S. Patent No, 2,657,618, issued to Walter Eisbein lof Stuttgart, Germany, on November 3, 1953, to which patent reference may be lhrad ici' la more complete understanding thereof.

It will thus be understood that the present invention provides a machine which is extremely simple and inexpensive in construction and foolproof in openation, and yet which provides a Wide Iiange of adjustment of the degree lof exposure. However, it should be emphasized 'that the particular embodiment of Ithe invention which is described herein and shown .in the accompanying drawings is 'intended as merely illustrative of the principles of the invention rather than as restrictive of fthe scope thereof, which is limited only by the appended claim'. l

-I claim:

In la photocopy exposure machine toi the type having means for transporting original 'and photosensitive sheets along a predetermined generally horizontal path, means for vaniably exposing said photosensitive sheet comprisying ra light source Located 4beneath said path, a mount assembly Isupporting said iight source, said mount being pivotally mounted on bearings splaced in ra generally horizontal direction vfrom said light source, lfor arcuate movement of said liglit source upwardly toward said path and downwardly away from said path, the weight ci said mount assembly and said light source urging said mount to pivot on said bearings in such angular direction as to move said light source downwardly away from said path, a cam surface formed on a projecting edge of said mount assembly, la stop member mounted in said machine ici` engagement of said cam surface and for adjustable movement in la `generally horizontal line at an angle to said cam surface, whereby movement of said stop member to different positions along said cam surface results in arcuate movement of said mount 'assembly and said light source to position said light source a preselected distance below said path.

References Cited in the ile of this patent UNITED STATES PATENTS 1,159,296 Trimblaoh Nov. 2, 1915 1,682,979 Oiller Sept. 4, 1928 1,721,202 Brown July 16, 1929 1,991,630 IRoss Feb. 19, 1935 2,228,642 Robentson lan. 14, 1941 2,699,703 Moureld Jan. 18, 1955 2,925,025 IConner Feb. 16, 1960

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