SU1195326A1 - Phtographic camera - Google Patents

Description

The invention relates to film photographic equipment, in particular to devices for automatic focusing and exposure testing, and can be used in cameras and film equipment.

The purpose of the invention is to simplify the design and reduce the size.

FIG. 1 shows a diagram of a device with fixed mirrors of the ghost element; in fig. 2 is a diagram of the device with the element of doubling the image in the form of two rectangular prisms; in fig. 3 element of double image in the form of hinged mirrors.

The device consists of a shooting lens 1, a sighting device made in the form of a collective 2, a pentaprism 3, an eyepiece 4, a shutter 5, a mirror 6, an additional mirror 7 placed perpendicular to the plane of the mirror 6 with an offset from its center, aperture 8, an additional lens 9, the element of ghosting the image in the form of a beam-splitting mirror 10 and inclined mirrors 11 fixed or pivotally mounted on the same axis, light detector 12 of the exposure metering system, substrate 13 in which plane the lights are located Receivers 12 and two sets of photoelectric receivers 14 of the camera’s autofocus system, signal processing electronics 15, engine 16, gearbox 17, indicator 18. The ghost element can be made of two glued rectangular prisms 19 mated by beam-splitting surfaces and acute angles constituting 35-55 °, and a plane-parallel plate 20, consisting of two wedges, moving relative to each other. Changing the thickness of the plate 20 provides the offset of one of the images along the axis of the system for carrying out the adjustment. In the element of ghosting all three mirrors can be made with the possibility of a hinge turn around a common axis, either jointly or separately at different angles.

Light detectors 12 and 14 and the electronic unit 15 can be performed on a single substrate 13 or placed independently, and on the substrate 13 for them

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holes may be provided.

The electronic unit 15 for processing signals received from the light-receivers 12 and 14 can also be autonomous.

5 Letters Р, and Р ₂ designate the transferred focal planes of the conjugate plane Р. With the help of an additional lens 9, an image of the object is transferred to these planes, and the images are distributed both along and across the optical axis of the system using the ghost element. Aperture 8, limiting the field of view of the autofocus system

15 and exposure metering, is performed in such dimensions that an additional lens 9 and mirrors 10 and 11 form two images of the same object, not superimposed

20 FRIEND to each other. Each light receiver 12 has only its own image of the same area of the object. Light detectors 12 operate and measure the exposure, not integrally,.

25 and according to the details of the object, and may be of considerable size, which provides for the determination of the exposure, when the ambient illumination of the object.

The device works as follows.

The luminous flux, passing through the lens 1, hits the mirror 6, δ reflects the sighting device and is sent to the observer's eye. Other part of the luminous flux through

35, the central part of the mirror 6, made translucent, with the help of an additional mirror 7 is reflected into the bottom of the camera and forms images in the mating focal plane r, which with the help of an additional lens 9 and ghost element of the image forms two images of the same part of the object, not superimposed and spaced apart in two planes P, and P ₂ both along and across the optical axis of the system. On the sets of light receivers 14 falls the same image area. The signals from the light-receivers 14 are processed using an electronic circuit that highlights the contrast function that controls the operation of the motor 16. Through the gearbox 17, the shooting lens 1 is moved. The exact focusing moment comes at the moment the images, P, and P ₂ are located

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symmetrically with respect to the plurality of light-receivers 14.

Part of the luminous flux that enters the light-receivers 12 of the exposure metering device. it is processed by one of the known methods and controls the operation of the shutter 5 or the lens 1 of the camera, automatically working out the exposure.

Moving an extra

Lens 9 along the optical axis can be obtained in the plane of the light-receivers 14 different magnification, corresponding to the dimensions of the design of the camera. At the same time increase - 15

The system can be larger than one, which makes the system more sensitive to defocusing.

Simplification of the design. Photo camera - ₂ 0 and increase of its compactness

ensured by the fact that the light detectors of the exposure and autofocus systems are served by a common optical scheme and are located, including ^λ electronic signal processing circuit, on a single substrate; here can be placed mounted and trim elements, which eliminates unnecessary connecting wires in the camera, unnecessary soldering operations, increasing the reliability of the system as a whole. Autofocus, exposure and processing can be carried out simultaneously, reducing the time for preparatory operations when shooting. In addition, this placement of the light-receivers and a single optical scheme for them increases the illumination both in the viewfinder and on the light-receivers of the autofocus device.

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FIG. one

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Claims (3)

1. A CAMERA, containing successively arranged lens, a mirror, perpendicular to the plane of which with displacement relative to its center, an additional mirror, an element of ghosting of the image, two systems · light guides of the autofocusing and light measuring devices, as well as a viewer and a shutter are installed; And with the fact that, in order to simplify the construction and reduce the size, it is equipped with a field diaphragm and an additional lens located in front of the ghost element images made in the form of an additional lens of the beam-splitting mirror installed at an angle to the optical axis and two inclined mirrors located on both sides of it, forming corresponding focal planes interfaced with the focal plane of the main lens and located at an equal distance from the plane of the location of the light receivers of the autofocusing and light measuring devices . _ 2. The camera p. ^ Characterized in that the element of ghosting of the image is made as a block of two rectangular prisms with a common hypotenuse beam splitting face, the angle of inclination to the optical axis of the additional lens of which is 35 - 55 °. 3. Camera on π. 1, in that the mirrors of the ghosting element are hinged on the axis. • 1195826 1 1195326 *