DD206250A1 - PHOTOELECTRIC MEASURING DEVICE FOR CAMERAS - Google Patents

Abstract

THE INVENTION CONCERNS A PHOTOELECTRIC MEASURING DEVICE FOR CAMERAS. THE OBJECT AND OBJECT OF THE INVENTION IS THE IMPROVEMENT OF AN OPTIONAL INTEGRAL, PARTIAL INTEGRAL OR SPOT MEASUREMENT, WITHOUT THE NEED TO CHANGE THE SINGLE PHOTO RECEIVER OR TO USE DIFFERENT OPTICAL SYSTEMS TO TRANSFER THE OBJECT LIGHT TO THE RECIPIENT, AND TO OPTICALLY CONTROL THE SELECTED METHOD. ACCORDING TO THE INVENTION, A PHOTO MEMPER SWITCHED TO A MEASURING MEASUREMENT AND / OR A FOCUSING AUTOMATIC SYSTEM IS ASSIGNED AN ELECTROOPTICAL PICTORIAL FILES, OF WHICH THE PARTICULAR PANELS ARE MADE TO FIXED INDIVIDUAL ELECTRODES AS A RESPONSIBILITY TO THE SELECTED SUBSTANTIAL GRAPH. SPOT MEASUREMENT A MORE OR LESS LARGE NUMBER SIMULTANEOUS WITH A VIEWABLE IN THE CAMERA SEALER AND IN SEVERE FORM OF THE SINGLE ELECTRODES OF THE PICTORIAL FILTERING CORRESPONDING ELECTRIC OPTICAL VARIO PICTURE FRAMEWORK IS POSSIBLE.

Description

242541

Dresden, July 30, 1982 21 / 4-03

Title of the invention

Photoelectric measuring device for cameras Field of application of the invention

The invention relates to a photoelectric measuring device for cameras, with an optional the entire object or only a 'part of the same auszusetzenden photo receiver,

Characteristic of the known technical solutions

For optional integral or "spot measurement" it is known to make the photo receiver arrangement of the camera movable

10 "or the same different optical systems to assign or select from a plurality of photoreceptors a more or less large number, s, DD-FS 128 716, DS-AS 21 16 238, DS-AS 25 59 559, DE-OS 27 These known devices are too expensive for the intended purpose, both in mechanical and in electrical engineering terms.

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Object of the invention

With the invention, measuring devices of the type described should be improved «

24254 1 O

Explanation of the nature of the 5 rf in dung;

The object of the invention is to provide a photoelectric measuring device for cameras with an optional the entire object to be exposed or a part thereof to be exposed photoreceiver, in which neither a movement of the single photoreceptor nor the use of different optical systems for 'forwarding the object light on the latter required and in which the type of measurement selected is additionally optically controllable «

According to the invention, this object is achieved in that the switched to a Belichtungsmeßschaltung or / and an automatic focusing photo receiver is associated with an electro-optical ^ field stop, of which the respective Meßfeldgröße adapted 3 ± ηζelelektroden depending on the selected ¹ T ei! Spot metering a more or less large number simultaneously with a visible in the camera viewfinder and in its form the individual electrodes of the field stop corresponding elek- * trooptischen 7 ar-ï-BiI df el dr ahmen is controllable,

AusführunssbeiSOiel

The invention will be explained below with reference to an embodiment beisnieles. Ss show:

• o ¹ ·

Figa 1 Total optical system of the camera, schematically Fig. 2 Electro-optical ^ field diaphragm with control connections

Fig. 3 Electro-optical Vario bilafield frame with control connections

3 2 ^ 2541

On the partially mirrored surface of a Paataprisma 1 a light-concentrating auxiliary prism 2 is arranged behind the light exit surface in the W & he an image plane is an electro-optical field stop 3, This aperture is followed by a photoreceiver 4. The latter is in the input of an exposure control circuit, not shown and / or a Focusing automatic switched »The field stop is connected via lines 5 to 8 with a control circuit 9 in connection, which is controlled by a push button 10. The drive circuit 9 is also connected via lines 11 to 13 with an electro-optical Vario image field frame 14 which is associated with a field lens 15. According to Figures 2 and 3, the image field 3 shown on an enlarged scale and the Vario Bildfeidrahmen from in. Inactivated State transparent Blendereieselektroden 1o to 19 and the latter adapted in shape BiIdfeldrahmen electrodes 20 to 22, which via control terminals 23 to 26 and 27 to 29 and the designated lines

20-5 to 8 and '12 to 13 are connected to the drive circuit 9,' The form of the 'single electrodes can also the limitation of a visible in the viewfinder micro prism grid and. adapted to a matte screen field *

The mode of action is the following:

In a 'desired integral measurement of the push-button 10 is not actuated, so that neither one of the aperture electrodes 16 to 19 nor one of the frame frames Slektroden 20 to 22 is driven «Consequently, the electro-optical field stop 3 remains fully open and the photoreceptor 4 is of the Light hit, which differs from the total image field visible in the camera viewfinder

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no frame frame electrode is limited, goes out. If a partial integral measurement of different degrees is to be carried out for the sake of acceptance, the key switch must be actuated once or twice ». Control circuit 9, the aperture electrodes 16 and 17 and, 16 to 18 are driven, so that the surface between the aperture electrodes 16 and 17 bsw _e 16 to 18 opaque »Due to the field effect, the photoreceptor 4 is in the gewünschter manner only the exposed by a subarea of visible in the camera view total scene outgoing luminous flux .. This subarea is in the camera viewfinder at any time controllable by simultaneously with. the designated aperture electrodes one of the per se transparent image frame frame electrodes 20 or 21 driven and therefore becomes visible * When desired spot measurement of the push button 10 is to be operated three times by the thus-effected control of the Blsndenelektroden 16 to 19, the between these electrodes lying flat opaque, and the photoreceptor 4 is exposed only to the light which passes through the limited area of the diaphragm electrode 19. "In order to make the selected spot measurement to make recognizable, the Bildfeldrahmeη-22 is selectively controlled and consequently as the only image field boundary in Camera viewers visible »

The marking of the selected partial integral or spot measurement in the camera viewfinder enables photographers to direct the camera only to the important scene in a simple way ". Measure is important not only for the correct adjustment of the exposure, but also for automatic focus cameras. In the latter case, the

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tion-oriented device in the depth staggered recording objects selectively scanned and the camera are therefore focused exactly on the image-important parts »The switch from integral to partial integral or spot measurement can also be done automatically instead of using the push button 10, if from. the focusing circuit is given due to the depth graduation of the receiving object no clear for the focus signal on the dashed line to the drive circuit 9 »

The selected and controllable in the camera view Teilintegral- or spot measurement remains due to the fact that the image field diaphragm and BiIdfeidrahmen preferably from a. largely thermostable ferroelectric cell with memory effect, even when the drive circuit 9 is switched off «The reset of the camera from a keyed spot measurement on integral measurement is done by pressing the push button 10 again.

The invention provides the basis for an increase in the yield of photographic images with regard to exposure and / or automatic focusing *

Claims (3)

A rting application 1 «Photoelectric measuring device for photographic cameras, with an optional to the entire object or a part of the same auszusetzenden Potoempfänger characterized in that your / an exposure or / and an automatic focusing switched photoreceptor associated with an electro-optical field stop (3), of which the respective Meßfeldgröße matched Individual electrodes (16 to 19) depending on the selected Teilintegral- or »spot measurement a more or less large number simultaneously with a visible in the camera viewfinder and in its shape to the individual electrodes of the field stop corresponding electro-optical Vario Bildfeidrahmen (14) is controlled 2. Measuring device according to item 1, characterized in that electro-optical field diaphragm and electro-optical Vario Bildfeidrahmen preferably each consist of a ferroelectric cell with memory effect « 3β measuring device according to item 1, characterized in that the individual electrodes of the Tario frame are adapted to the boundary of an existing micro-prism grid and a Mattscheibenringfeldes _o 4e measuring device according to item 1 _r, characterized in that the Meßart manually by means of a push-button switch (10) which is connected to a circuit (9) for driving the Bildfel dblende and the Yario image field frame, selectable and the selected Meßart means preferably of the same key switch is erasable. 5. Measuring device according to point i, characterized in that the circuit (9) for controlling the field stop and BiIdfeidrahmen means of an indifferent signal of the automatic focusing is activated _o (For this 1 sheet drawing)