GB2088573A

GB2088573A - Variable magnification photocopier

Info

Publication number: GB2088573A
Application number: GB8135474A
Authority: GB
Original assignee: BOEGER DUPLOMAT APPARATE KG DR
Current assignee: BOEGER DUPLOMAT APPARATE KG DR
Priority date: 1980-12-01
Filing date: 1981-11-25
Publication date: 1982-06-09
Also published as: GB2088573B; DE3045157C2; DE3045157A1

Abstract

In a photocopier having at least two interchangeable lenses on a slidable carriage, each lens has a diaphragm adjustment ring with three latchable positions, the three ring positions of the operative lens being indicated by means of two microswitches which respectively sense the two end ring positions. As shown, the end positions of a ring adjustment lever 16c are sensed by microswitches 13 & 14, and the end positions of lens carriage 15 are similarly sensed by microswitches 26 and 27. In another form (Figure 3), the rings are connected by a chain and a follower pin 30 of lens 11c, which passes through the chain, is sensed in end positions by the microswitches. In a third form (Figure 5), in which the carriage carries two lenses, the rings are operated independently. <IMAGE>

Description

SPECIFICATION Objective carriage arrangement in a reproduction camera The invention relates to an objective carriage arrangement for a reproduction camera, in which an objective carriage carrying at least two juxtaposed objectives is pivotable or translatable at right angles to the optical axis to selectively position the objectives in the beam path, and in which microswitches are provided for forming switching signals representative of the position of the objective carriage and/or the aperture diaphragms.

In reproduction cameras an original copy arranged on a table is imaged via an objective onto a photosensitive plate or a photosensitive film. In this arrangement two or more objectives are arranged on an objective carriage in order to make various enlargments possible. The objectives can be selectively positioned in the beam path by displacement of the objective carriage at right angles to the optical axis. In a known objective carriage arrangement the .position of the objective carriage, i.e. of the objective which is currently located in the beam path, can be ascertained by microswitches operating between the objective carriage and the camera frame, and this information can, for example, be passed back to an information panel or to an exposure time control device.Furthermore, in a known objective carriage arrangement (US-PS 3996 596) provision is already made for the adjustment of the aperture diaphragm generally provided at each objective to be detected by means of microswitches and for this information to be passed to an exposure control apparatus orto an indicator panel. For this purpose levers or extensions provided on the aperture adjustment rings cooperate with the microswitches provided on the objective carriage.

The known objective carriage arrangement has however the disadvantage that a very large number of microswitches is required for the various objectives and aperture diaphragm positions.

The object of the present invention is, in contrast, to provide an objective carriage arrangement of the initially named kind in which one can manage with a significantly reduced number of microswitches without significantly restricting the variety of adjust ments.

In order to satisfy this object the invention envisages that the aperture adjustment rings of all the objectives can be selectively latched into only three positions and that only two microswitches are provided for forming the switching signals, with these microswitches detecting the two end positions of the aperture diaphragm that is located in the beam path.

The thought underlying the invention thus resides in restricting the variety of adjustments of all the aperture adjustment rings to three ideal apertures and to use only two microswitches (on-off-switches) to indicate these three positions. The invention thus starts from the recognition that, by way of example, a choice of the aperture numbers 11, 16 and 22 is completely sufficient for all the reproduction problems which occur in practice. In general the two extreme aperture numbers 11,22 are indicated by actuation of a respective one of the two microswitches. For the intermediate aperture number (for example 16) neither of the two microswitches will be actuated so that this position of the aperture adjustment ring can also be indicated by suitable interconnection of the two microswitches.

The objective carriage arrangement of the invention can also be used with particular advantage with an objective carriage equipped with a wide angle objective. Wide angle objectives namely have ideal resolution forthe working aperture No. 22. Stopping down results however in a very pronounced deterioration of the image sharpness and the light distribution. The light distribution between the aperture is however substantially correct for wide angle objectives. As the aperture stop is used in reprographics almost exclusively for screening a moderate loss of sharpness can be tolerated. For extreme reductions and when using films of particularly high sensitivity very short exposure times can arise when using the aperture No. 22.In order to prevent exposure times for reproduction cameras of less than 1.5 seconds an indication is given in such cases in the exposure control apparatus whereupon a grey filter, which achieves an extension of the exposure by a factor of at least 5, is swung, either by hand or automatically, in front of the selected objective.

In a first advantageous embodiment the microswitches are arranged on the objective carriage and the aperture adjustment rings are connected together via a transmission so that they can be jointly positioned in a respective one of the three positions. The arrangement should be such that all the objectives have the same diaphragm adjustment angle per diaphragm step and are rotationally fixed coupled together by the transmission.

It is thus particularly preferred for the aperture adjustment rings of all the objectives to be rotatable through the same angle in orderto select the same aperture and for them to have a perceivable aperture latch. In this case the coupling transmission can be realized in the simplest manner, for example by a lever arrangement or by a chain passing around all three aperture adjustment rings. All the aperture adjustment rings can then be jointly actuated by a single lever. As a result of the interconnection of the aperture adjustment rings the normally easily moved aperture latches are made substantially more effective in the desired manner by the additive effects of all the coupled latches.

In the above named embodiment the two microswitches are preferably end stop switches and are preferably constructed as simple on-off pressure switches. The actuating lever when moved into either of its two extreme positions, changes over the associated microswitch from one switch position to the other. When the actuating lever is in intermediate positions both microswitches assume their other switch positions.

In an alternative embodiment of this invention the individual aperture adjustment rings are independently adjustable and cooperate with two microswitches which are mounte on the camera housing.

Each aperture adjustment ring is only in operative association with the microswitches when the associated objective is positioned in the optical beam path.

This embodiment is particularly suitable fo.r objective carriages which are interchangeably mounted on the camera frame because it is not necessary for wiring to pass from the camera frame to the objective carriage.

For the practical realization of this embodiment the invention envisages that the aperture adjustment rings carry pressure plates with engagement ramps which, on displacement of the objective carriage and or rotation of the aperture adjustment rings, can slide over actuating members of the microswitches which are displaceable in the direction of the optical axis and thereby actuate the microswitches.

It is already known that the position of an objective carriage carrying three objectives can be indicated by means of microswitches (US-PS 37 79 642). Claim 11 however defines an embodiment in which three positions reached by translation or pivotal movement are indicated by only two microswitches.

The invention will now be described in the following by way of example only and with reference to the drawings which show: Figure 1 a schematic, perspective view of an objective carriage arrangement having three juxtaposed objectives, Figure 2 a schematic, perspective view of the translation mechanism for the objective carriage arrangement of Figure 1, Figure 3 a perspective view of a further embodiment of an objective carriage arrangement, Figure 4 a schematic, reduced, plan view of the subject of Figure 3 showing a drive mechanism for adjusting all the objectives simultaneously, Figure 5 a schematic perspective view of an alternative objective carriage arrangement with only two objectives, Figure 6 an enlarged, schematic side view of a pressure plate used in the embodiment of Figure 5, and Figure 7 a preferred circuit for the two microswitches as used in the above arrangements.

As seen in Figure 1 an objective carriage 15 is arranged in a reproduction camera which is not shown in detail. In the position shown in Figure 1 the optical axis 22 of the carriage 15 extends through the middle one of the juxtaposed objectives 12a, 1 2b, 12c. Beneath the central objective 12b there is located in the direction of the arrow V, an original copy which is to be produced by the reproduction camera. The film onto which the original copy is to be imaged by the objective 12b is located above the objective carriage 15 in the direction of the arrow F.

The objective carriage 15, which is constructed as a rectangular plate, has guide blocks 25 on its underside by means of which it can be displaced at right angles to the optical axis 22, on guide bars 24 which extend parallel to one another at right angles to the optical axis 22 and are fastened in nonillustrated manner to the camera frame, so that the three juxtaposed objectives 1 2a, 1 2b and 1 2c on the objective carriage 15 can be selectively brought one afterthe other into the beam path (optical axis 22).

On the copy board 19 there are arranged microswitches 26, 27 which are spaced apart along the longitudinal side of the objective carriage 15 in the direction ofdisplacementfofthe objective carriage.

The microswitches cooperate with an abutment 29 fastened to the objective carriage 15. In Figure 1 the abutment 29 is located directly in the centre between the two microswitches 26,27. The two microswitches 26, 27 are thus not actuated and this signals the arrangement of the central objective 12b in the beam path.

If the objective carriage 15 is now displaced in the direction of the arrows the abutment 29 will contact one of the microswitches 26 or 27 as the objective 12a or 12c is positioned in the beam path on the optical axis. When the abutment 29 contacts one of the microswitches 26, 27 the switches transmit a position signal which is representative of the arrangement of the objective 12a or 12c in the beam path. The construction and circuitry for the microswitches 26, 27 can be the same as is described below fortheswitches 13, 14 with reference to Figure 7.

The displacement of the objective carriage 15 on the guide rods 24 makes it possible to selectively bring one of the objectives 12a, 12b or 12c into line with the optical axis 22. At each of the objectives 12a there is located an aperture adjustment ring 1 1a, 11 b or 1 which are rotatable in the direction of the double arrow in order to select various apertures. In accordance with the invention the aperture rings have latches or detents which make it possible to select only the aperture numbers 11,16 and 22. The latches can take the form of a simple arrangement e.g. a spring loaded ball in the apertured adjustment ring and three mating notches in the body of the associated objective. Similar detent arrangement can be used to secure the objective carriage 5 to the copy board 19.

For the purpose of jointly driving the aperture adjustment rings 11 a, b, c, the axes of rotation of which coincide with the optical axes of the objectives 12a, b, c, each aperture adjustment ring 1 lab, c c has at its underside a follower pin 30 which engages in an elongate slot 31 provided at the end of the one lever arm of a respective lever 16a, b, c in the longitudinal direction of the lever. The levers 16a, b, care pivotally arranged on the objective carriage 15 about pivot axes or axles 32a, b or c which extend parallel to the optical axis 22. The extent of the elongate slot 31 is such that on pivoting of the levers 16a, b, cthe aperture adjustment rings 1 1a, b, care driven to execute a pivotal movement from aperture number 11 to aperture number 16 to aperture number 22 or vice versa.

The arms of the levers 16a, b, c remote from the elongate slot 31 are respectively pivotally connected to different points of a drive bar 17 which extends parallel to the line connecting the axes 32a, b, c. The pivot axes between the levers 16a, b, c and the drive bar 17 extend parallel to the axis 32a, b, c and to the optical axis 22.

The central lever 16b has, in the opposite direction to the elongate slot 31, an extension 33 which represents the actual actuating lever for the whole aperture adjustment ring assembly.

If the actuating lever 33 is actuated in the direction of the double arrow W all three aperture adjustment rings 1 1a, 1 1b and 1 1c will be jointly moved through the same angle. As a result of the fact that each aperture adjustment ring latches in only three aperture positions (aperture numbers 11, 16, 22) either the aperture number 11, the aperture number 16 or the aperture number 22 can be selected at all the objectives 1 2a, b, c by means of the actuating lever 33. The detent or latching action of the three aperture adjustment rings 11 a, b, c is additive so that each ofthe individual aperture positions is reliably defined.Two microswitches 13, 14 are mounted on the objective carriage 15 on both sides of the lever 1 6c near the lever arm associated with the elongate slot 31. The arrangement of the microswitches 13, 14 is such that they are activated in the two end positions of the levers 16a, b, c by lever 1 6c and are moved into one of their two switch positions. In Figure 1 the two end positions of the lever 1 6c are illustrated in chain dotted lines. The central position of the levers 16a, b, c and the aperture adjustment rings 1 lab, c c is illustrated in full lines in Figure 1.

If the actuation lever 33 is actuated in the direction of the double arrow W the three aperture adjustment rings 1 la, b, c can be adjusted from the illustrated central position either into the one end position in which the microswitch 13 is actuated by the lever 1 6c or into the other end position in which the microswitch 14 is actuated by the lever 16c. The opening of the two microswitches 13, 14 is thus an indication of the central position of the aperture adjustment rings 11 a, b, c whereas the two end positions corresponding to the aperture numbers 11 or 22 are signalled by the changing over of the microswitches 13, 14 into their other switch positions.

Figure 7 shows a possible circuit for the two microswitches 13, 14to generate switching signals representative of the three possible aperture adjustments.

The switching arms of the microswitches 13, 14 are biased by springs 34 towards an open rest position which they adopt when the aperture adjustment rings 1 lea, b, care in the position illustrated in solid lines.

A voltage is passed via a terminal D to the switch arm of the microswitch 13. The break contact E of the microswitch 34 is electrically conductively connected with the switching arm of the microswitch 14.

The break contact of this microswitch contacts an output terminal B. The make contacts of the microswitches 13, 14which come into operation on actuation of the switch arms are connected to the output terminals A and C.

When the aperture adjustment rings 11 a, b, care located in the central position of Figure 1 the voltage at the terminal D is passed via the switching arm of the microswitch 13, the contact E and the switching arm of the microswitch 14 to the output terminal B.

No voltage is present at the output terminals A and C. A signal 0 1 Oat the output terminals A, B or C thus signifies the selection of the aperture number 16 at all three aperture adjustment rings 11a, b, c.

If now the actuation lever 33 is actuated so that the lever 1 6c acts on the microswitch 13 the switch arm of this microswitch will be brought into contact with the output terminal A so that the voltage at the terminal D is now present only at the output contact A. The condition 1 0 0 at the terminals A, B, C thus signals that the aperture number 11 has been selected.

In the other end position the lever 1 6c acts on the microswitch 14 with the switch arms adopting the position reproduced in Figure 7. The voltage supplied from the terminal D is now present solely at the terminal B so that the condition 0 0 1 at the terminals A, B, C shows that the aperture number 22 has been selected at all the objectives 12a, b, c.

Thus three different apertures at all three objectives can be unambiguously indicated using only two microswitches 13, 14.

The microswitches 13, 14 can be arranged at any suitable position at which a movement takes place during adjustment of the aperture diaphragms.

In Figure3the microswitches 13, 14 are for example arranged on both sides of a follower pin 30 which projects from one side of the aperture adjustment ring 11 c of the objective 12c. In the two end positions the follower pin 30 acts on and actuates either the microswitch 13 or the microswitch 14. The circuitry of the microswitches 13, 14 can likewise be arranged as shown in Figure 7. Other desired interconnections of the microswitches 13, 14 are however also conceivable it is only necessary to ensure that in each of the three possible aperture positions the circuit produces a different output signal which is representative of the three aperture positions.

In the embodiment of Figure 3 the transmission which rotationally fixedly couples the three aperture adjustment rings 11a, Ilband Ile is formed buy a chain 18 which is laid around the three aperture adjustment rings 11 a, b, c in the manner which can particularly be seen from Figure 4. A follower pin 30 projects radially from each of the aperture adjustment rings and engages through a link of the chain 18 so that the drive connection is established between the aperture adjustment rings 11 a, b, c and the chain 18.

In orderto ensure that the chain 18 also has a sufficient angle of wrap around the central aperture adjustment ring 11 b deflection pins 35 are arranged on both sides of the central aperture adjustment ring 11 b on the upper side of the objective carriage 15.

These deflection pins are inwardly displaced relative to the tangents to the three aperture adjustment rings 1 lab, b, c and thus ensure that the chain 18 has a sufficient angle of wrap around the aperture adjustment ring 11 b. The actuating lever 33 in the embodiment of Figure 3 is arranged at the central aperture adjustment ring 11 b and extends radially outwardly therefrom. The central position of the operating lever 33 is illustrated in solid lines whereas the two side positions corresponding to the aperture numbers 11 and 22 are illustrated in chain dotted lines.

If, in the embodiment of Figures 3 and 4 the lever 33 is moved in one of the directions of the double arrow W the aperture adjustment ring 1 Ic is primarily driven in a rotational movement. Through the follower pin 30 of the central aperture adjustment ring 11 b the chain 18 is however caused to execute a simultaneously circulatory movement which, via the follower pin 30 of the aperture adjustment rings 1 la, 1 1c, also causes these aperture adjustment rings to execute a synchronous rotary movement. In the two end positions the follower pin 30 of the aperture adjustment ring 11 c actuates the microswitches 13, 14.

In the same way as in Figures 3 and 4the same reference numerals designate also in Figures 5 and 6 the same parts as in the embodiment of Figures 1 and 2.

In the embodiment of Figures 5 and 6 the objective carriage 15 is so arranged in longitudinal guides 24 on the copy board 19 that it can be removed together with the objectives 12a, 12b mounted thereon from the reproduction camera. The aperture adjustment rings 1 lea, lib of the objectives 12a, 12b,which in this case are only two in number, are independently rotatably arranged on the objective carriage 15. End abutments 36,37 limit the angular positions of the two aperture adjustment rings 11 a, 11 b. The two aperture adjustment rings 11 a, 11 b can once again latch in any of three positions corresponding to the aperture numbers 11, 16 and 22. The latched end positions correspond to contact of the actuating levers 33 on the abutments 36,37.

Arms 38 extend in the radial direction from the sides of the aperture adjustment rings 11 a, 11 b opposite to the actuating levers 33 and have at their ends a respective pressure plate 21 the shape of which can be seen particularly clearly from Figure 6.

The pressure plates 21 have engagement ramps 20 at their sides which are preferably inclined at an angle of less than 45" to the horizontal or to the surface of the objective carriage 15.

The pressure plates 21 cooperate with microswitches 13, 14 which are fixedly arranged on the copy board 19 and which are spaced apart by a distance corresponding to the two aperture numbers 11 and 22.

The two microswitches 13, 14 are arranged to the side of the objective carriage 15 so that the pressure plates which are moved parallel to the plane of the objective carriage 15 can slide over the actuating members 23 of the microswitches 13, 14 when the pressure plates are moved from the side towards the microswitches 13, 14.

In Figure 5 there is shown in full lines the position of the objective carriage 15 in which the objective 12b lies on the optical axis 22 of the reproduction camera. The actuating lever 33 now contacts the left hand abutment 36 whereas the arm 38 is positioned so that the pressure plate 21 has slid over the actuation member 23 of the microswitch 14. This position corresponds to the aperture number 22.

If the actuating lever 33 is now pivoted in the direction of the arrow W to reach the position between the stops 36,37 illustrated in chain dotted lines the pressure plate 21 lies between the microswitches 13, so that neither is actuated.

If the actuating lever 33 is pivoted still further it abuts against the stop 37 and the pressure plate 21 slides by means of the engagement ramp 20 onto the actuating member 23 of the microswitch 13.

Whereas the central position corresponds to the aperture number 16 the actuation of the microswitch 13 corresponds to the aperture number 11.

By displacing the objective carriage 15 forwardly in the direction of the double arrow F of Figure 5 the arm 38 of the aperture adjustment ring 11 a comes into alignment with the microswitches 13, so that by appropriate actuation of the actuating lever 33 the pressure plate 21 of the aperture adjustment ring 11 a can be brought selectively into engagement with the actuating members 23 of the microswitches 13, 14 or can be arranged therebetween.

The engagement ramps preferably extend around the pressure plate 21 so that they can also slide over the actuating members 23, providing they are aligned therewith, when withdrawing or inserting the objective carriage 15 in the direction of the double arrow M. The sliding movement also occurs when the objective carriage 15 is displaced in the direction of the double arrowf.

It is thus important for the function of the invention that the microswitches 13, 14 are arranged spaced apart, either on the objective carriage 15 or alongside the carriage and fixed to the camera, at a distance which corresponds to the pivotal spacing of a member connected to the aperture adjustment rings 11 a, b, c during adjustment of the aperture diaphragms between the two extreme positions. The microswitches 13,14should be located approximately in the plane of or close to the plane of the objective carriage 15.

The removability of the objective carriage 15 of the embodiment of Figures 5, 6 makes it possible to replace the objectives 12a, 12b by other objectives (exchangeable objectives).

Claims

1. An objective carriage arrangement for a reproduction camera, in which an objective carriage carrying at least two juxtaposed objectives is pivotable or translatable at right angles to the optical axis to selectively position the objectives in the beam path, and in which microswitches are provided for forming switching signals representative ofthe position of the objective carriage and/or the aperture diaphragms, characterised in that the aperture adjustment rings (1 la, b, c) of all the objectives (12a, b, c) can be selectively latched into only three positions, and in that only two microswitches (13, 14) are provided for forming the switching signals, with these microswitches detecting the two end positions of the aperture diaphragm that is located in the beam path.

2. An objective carriage arrangement in accordance with claim 1 and characterized in that the microswitches (13, 14) are arranged on the objective carriage (15), and in that the aperture adjustment rings (11 a, b, c) are connected together via a transmission (16, 17; 18) so that they can be jointly positioned in a respective one of the three positions.

3. An objective carriage arrangement in accordance with claim 1 or claim 2 and characterized in that all the objectives (12a, b, c) have the same diaphragm adjustment angle per diaphragm step and are rotationally fixedly coupled together by the transmission (16, 17; 18).

4. An objective carriage arrangement in accordance with claim 2 or claim 3 and characterized in that the transmission is a lever transmission (16, 17).

5. An objective carriage arrangement in accordance with claim 4 and characterized in that a double-armed lever (16a, b, c) is arranged on the objective carriage (15) for each objective (12a, b, c) with one arm of the lever being in driving engagement with the associated aperture adjustment ring (11 a, b, c) and its other lever arm being in driving engagement with a common drive rod (17).

6. An objective carriage arrangement in accordance with claim 2 or claim 3 and characterized in that the transmission is a chain transmission (18).

7. An objective carriage arrangement in accordance with claim 6 and characterized in that all the aperture adjustment rings (ill, b, c) are surrounded by a chain (18) which is in driving engagement with each of the aperture adjustment rings (1 1a, bc).

8. An objective carriage arrangement in accordance with one of the claims 2 to 7 and characterized in that the two microswitches (13, 14) are end stop switches.

9. An objective carriage arrangement in accordance with claim 1 and characterized in that the two microswitches (13, 14) are fixedly arranged on the film support (19) so that the independently adjustable aperture adjustment rings (11 a, 11 b) are in operative connection with the microswitches (13, 14) in the various displaced positions of the objective carriage (15).

10. An objective carriage arrangement in accordance with claim 9 and characterized in that the aperture adjustment rings (11a, b) carry pressure plates (21) with engagement ramps (20) which, on displacement of the objective carriage (15) and/or rotation of the aperture adjustment rings (11 a, 11 b), can slide over actuating members (23) of the micros witches (13, 14) which are displacable in the direction of the optical axis and thereby actuate the microswitches (13, 14).

11. An objective carriage arrangement in accordance with one of the preceding claims and characterized in that the objective carriage (15) has three objectives (12a, bc), and accordingly three positions to which it can be translated or pivoted, and in that a respective microswitch (26,27) is provided only for the two outer positions, with each microswitch being actuated by an abutment (29) arranged on the carriage (15).

12. An objective carriage arrangement substantially as herein described with reference to and as shown in the accompanying drawings.