DE2151288A1 - Device for winding and unwinding dimming curtains in copiers - Google Patents

Description

DR. BSRG DIPL.-ING. STAPF

PATENT / NW /. LT E " f. | QI 288

8 MUNICH 8O. MAUERKIRCHERSTR. 43

I. Dr. Berg Dipl.-Ing. Stopf, 8 Munich 80. Wall church nitroBe 45

Your mark, your writing «! Our sign 21 5Ö1 Dahim. | T | October 1971

Attorney file 21 581

Kabushiki Kalsha Ricoh Tokyo / JAPAN

Device for winding and unwinding blinds

in copiers.

The invention relates to a device for winding and unwinding anti-glare curtains for copiers moving optical system.

In the case of copiers in which an

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renden original and a light-sensitive "recording medium arranged optical system for exposing the recording medium with an optical image of the original and carries out forward movements, anti-glare curtains guided along the movement guide of the optical system are provided. They are each with one end on the optical system and with the other on the ends of the motion control The winding shafts arranged in the optical system are attached and serve to protect the recording medium from exposure through scattered light emanating from a light source for illuminating the original.

Previously it was customary to have the blinds depending of the to and fro movement of the optical system onto the respective shafts or from these, wherein slack in the curtains and interference with the reciprocating motion of the optical system had to be avoided.

The invention solves the problem of providing a device for and unwinding of anti-glare curtains without the conventional ones To create devices for driving the winding shafts used for winding the curtains in question. In a device of the type mentioned, in accordance with the invention there is both excessive tightening and slackening the glare curtains avoided when winding and unwinding the same on or from the winding shafts.

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This results in the device according to the invention, the advantage that the curtain arrangement for copiers with moving optical system compared to corresponding arrangements of known type has a significantly longer service life.

Further features, details and advantages of the invention emerge from the following description of an exemplary embodiment based on the drawing. It shows:

1 shows a schematic side sectional view of the exposure part a copier with a known device for winding and unwinding dimming curtains,

FIG. 2 shows a partial oblique view with that in the device according to FIG. 1 for driving the curtain winding shafts spiral spring arrangement used,

Fig. 3 is a side view of a device for up and Unwinding the blinds according to an embodiment of the invention and

FIG. K shows a partial sectional view along the line AA in FIG. 3.

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In Fig. 1, an original 3 to be copied is on a transparent or translucent one carried by a holding plate 1 Original table 2 is placed, an optical system 7 is arranged at the bottom left in the figure. It includes one at his Rear projection lens integrally connected to a mirror 4 5 and one in a horizontal plane in which the optical axis 0 of the objective 5 runs V-shaped mirror 6. The edge of the V-shaped mirror 6 runs in the plane perpendicular to the optical axis 0. Two V-shaped mirror surfaces are each at an angle of 45 to the horizontal plane.

The optical system 7 is installed in a system slide 8. Near the right upper end of the carriage 8 is one mounted on the rear side covered by a shield 9 light source Io. At the lower right end is on the slide a shutter 11 hinged. As indicated by dash-dotted lines in FIG. 1, one runs with its two ends on the slide 8 attached wire 12 around castors 13 and 14. The rollers 13 and 14 are some distance below the two ends of the original table 2 arranged so that they do not interfere with the reciprocating movement of the optical system 7.

The system carriage 8 is essentially on rails or other suitable guide devices in relation to the original table parallel plane can be moved back and forth and moves.

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under the drive of the rollers 13 and 14 from left to right. It moves along the original 3 to a recording medium 15 to be exposed with an optical image of the original 3. The recording medium 15 is by means of a The belt 18 guided over rollers 16 and 17 is transported and pauses briefly when the drive of the belt 18 is interrupted in the position shown in FIG. 1, the position opposite the original 3. The recording medium 15 by means of a vacuum box 19 arranged between the upper and lower run of the belt 18, it is flat and level held down.

Above the system slide 8, two anti-glare curtains 2o and 21 run along its path of movement. The curtain 2o has one end at a tubular winding shaft 22, which is initially supported at an end point of the reciprocating movement of the optical system slide 8, and the other end 2oa is at the left end of the top of the system slide 8 attached. The curtain 21 is fastened with one end to a tubular winding shaft 23 initially supported at one end point of the reciprocating movement and with the other end 21a on the right end of the upper side of the system carriage 8. In the starting position of the optical system 7 shown in FIG. 1, the dimming curtain 2o is wound onto the shaft 22 and the other curtain 21 is unwound from its shaft 23 and kept under tension.

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The two tubular winding shafts 22, 23 are rotatable fixed support shafts 24 and 25 respectively.

To support the winding shaft 23 on the holding shaft 25 are on the latter bearing 26 and 27 arranged (Fig. 2). A spiral spring 28 is attached to the bearing 27 at one end. That other end "of the spring 28 is conveniently attached to the Winding shaft 23 anchored. The spring 28 is able to store a sufficiently large amount of energy in order to complete the screening curtain 21 wind up on the shaft 23. In Fig. 1, in which the optical system 7 is in its starting position, the curtain 21 is unwound from the shaft 23 against the elastic tension of the spring.

An identically designed spring serving the same purpose is between the other winding shaft 22 and its holding shaft 24 arranged. Bi is thus the state shown in FIG. 1 the curtain 2o is completely wound onto the winding shaft 22 under the elastic tension of the spring.

The described arrangement of the conventional blinds has the disadvantage that the spiral springs are subject to considerable stress are exposed and they therefore only have a relatively short service life. The two coil springs in the Winding shafts 22 and 23 become with each reciprocating movement of the optical system 7 for exposing a recording medium very excited with an image of a template

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and relaxed. As long as the optical system 7 remains motionless, one spring is constantly under tension. These strong ones. Stress on the springs can lead to rapid fatigue and early replacement is necessary do.

In the following description of the embodiment of the invention "Forward movement" or an equivalent term means movement of the optical system to the right in Fig. 3 and "backward movement" the movement to the left.

In Fig. 3, an optical system is of the same construction as the optical system 7 in Fig. 1 with a V-shaped mirror 32 and the other components are arranged on a system slide 31. This is like the optical system 7 according to FIG. 1 optical system in Fig. 3 guided between an original table and a recording medium.

On one side of the system carriage 31 there are two integral parts on a rail formed by a rod 33 freely movable pipe socket 3 ^ and 35 attached. On the other side of the carriage 31 are on a rail (not shown) running parallel to the rail 33 Slidably movable (not shown) sliding shoes are provided. The system slide 31 is thus through the pipe socket

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34, 35 and the sliding shoes are movably guided on the two rails.

On the pipe socket 34 and 35 is by means of pins 37 and 38, respectively a tab 36 with two connection fittings 39, 4o seated thereon is attached. The connection fittings 39 »40 each carry a fastening part 4l or 42 for a belt. A ™ toothed belt 43 is formed with at both ends eyelets are attached to the fastening parts 41 and 42.

The toothed belt 43 runs over a drive wheel 44, a driven wheel 45 for a winding shaft, an intermediate wheel 46, another driven wheel 47 for a second winding shaft and another intermediate or deflection wheel 48. At the On the outside of the toothed belt 43 there are tensioning rollers 49 and 50 under pressure in contact.

The driven wheels 45 and 47 for the winding shafts are together with a rear winding shaft 53 and a front one, respectively Winding shaft 54 for dimming curtains rotatable on fixed Shafts 51 and 52 mounted.

A front dimming curtain 55 has one end 55a up attached to the front end of the system carriage 31 and at the other end to the winding shaft 54. A rear blind 56 is with one end 56a at the top of the rear end of the system carriage 31 and with the other end on the winding ' shaft 53 attached.

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As FIG. 4 shows, j is between the driven wheel 45 and a torsion spring 57 loosely pushed onto the fixed shaft 51 is inserted into the winding shaft 53. She is sitting with one End 57a in a bore 45a formed in wheel 45 and with its other end 57b in a bore 58a in a bearing bushing 58 carrying the winding shaft 53. The driven Wheel 47 and the winding shaft 54 are by means of a similar Torsion spring connected to one another, which, however, is wound in a direction opposite to that of the torsion spring 57.

The torsion springs shown and described can be designed as helical springs or other suitable spring elements be.

When the drive wheel 44 is rotated in the direction of arrow a (FIG. 3), the system slide 3i moves along the rails forward. When the end point of the forward movement of the system slide 31 is reached, the direction of rotation is of the drive wheel 44 reversed, so that the carriage returns to its starting position. During these operations will the original is scanned and the recording medium in the manner described with reference to FIG. 1 with an optical Image of the original exposed. Simultaneously with the above-explained back and forth movement of the system slide 31 the winding shafts 53, 54 via the driven wheels 45 or 47 driven in the corresponding directions, so-

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that the former first unwinds its dimming curtain and the latter unwinds its dimming curtain. This is a smooth movement of the two blinds guaranteed. Provided that a certain amount of dimming curtains is permitted appears, the driven wheels and the winding shafts can be rigidly together without the use of springs or the like be connected.

If a torsion or helical spring is inserted between the driven wheels and the respective winding shafts, so it increases its tension depending on the thickness of the winding shaft on which the

Curtain is wrapped, possibly occurring lower
differentiate the rotation speed / of the driven gear and winding shaft, so that the blinds are neither too slack nor too tight when they move.

Are the diameters of the driven wheels and the average thickness of the winding shafts when winding the blinds in question Coordinated with one another from the outset, the torsion or helical spring experiences only a very small amount Twist and therefore may have an extended service life.

In the embodiment described above is a drive system with a toothed belt and corresponding Used driving and driven gears. Instead of one

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However, the arrangement can also be a drive system with a cable drive and corresponding rollers or with a link chain and sprockets are used. To attach the two blinds to the ends of the slide for the optical system can serve double-sided adhesive strips or rivets.

The invention thus creates a device by means of which an exposure of a light-sensitive recording medium can be carried out by scattered light emanating from a light source for illuminating an original to be copied through use can be prevented by blinds. The device is particularly suitable for copiers in which a between the original and the recording medium arranged optical system for performing a slit exposure back and forth outgoing movement.

- 12 patent claims:

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Claims (2)

Patent claims: Device for winding and unwinding dimming curtains for copiers, characterized by a between one to copying original and one of these opposite arranged photosensitive recording medium for exposing the Recording medium with an optical image of the original along a parallel to the original and the recording medium running path back and forth movable optical system, by first the front and the first rear end point of the trajectory of the optical system arranged front or rear winding shaft (54 or 53) for a front or rear dimming curtain (55 or 56), the front dimming curtain (55) having one end (55a) at the movable optical system and with the other end attached to the front winding shaft (5 * 0 and the rear curtain (56) with one end (56a) on the movable optical system and attached at the other end to the rear winding shaft (53) is, and by drive devices (43 to 5o) for the rotary drive of the two winding shafts for the dimming curtains depending on the back and forth movement of the optical System, wherein the winding shafts can be driven by means of the drive devices so that when unwinding the a dimming curtain the winding of the other curtain can be brought about. - 13 2Ü9830 / ÜS10 2. Apparatus according to claim 1, characterized in that each of the two winding shafts (53 ₃ 54) for the dimming curtains (56 or 55) are rotatably mounted on a fixed shaft (51 or 52) that are each mounted at one end of the fixed shafts a wheel (45 or 47) which can be driven in dependence on the back and forth movement of the optical system is arranged for driving the respective winding shaft and that a torsion spring (57) is arranged in each case between the driven wheel and the respective winding shaft. 209830/0510 Blank page