SU502354A1 - Automatic lens fuses device - Google Patents

Description

one

This invention relates to the optomechanical industry.

Automatic lens focusing devices are known, comprising an electrically operated lens holder, a beam splitter, a photodetector array, an electronic signal conditioning unit, and a control unit associated with the lens holder actuator.

The purpose of the invention is to improve the accuracy and speed of the device.

The proposed device is characterized in that the photosensitive surface of the photodetector matrix is rotated relative to the focal plane of the lens in a plane perpendicular to the rows of the matrix, and the electric drive is equipped with a lens position sensor, one of the parallel outputs of which is switched to the inputs of controlled gates of the signal conditioning unit through the clock switching unit and the other output is connected to the inputs of the switching valves of the signal amplifiers, the outputs of which through the coincidence circuit are connected to the switch-on relay Electric drive.

Diagram of the device shown in the drawing.

The device contains a photosensitive recorder 1, an optical image divider 2, a photosensitive matrix 3, a lens position sensor on focusing;

thread 4, electric drive 5, clock switching unit with generator 6, amplifiers 7, schemes for generating differential focus signals 8, valves 9 for switching the inputs of amplifiers, capacitive accumulators of differential signals at even clock 10, capacitive accumulators of differential signals at odd clock 11, amplifiers of differential signals focusing 12, comparison circuit 13, valves 14 for switching the outputs of amplifiers, major elements of switching on the electric drive for reverse stroke 16, relay for switching on the engine reverse stroke 17, relay for switching on the motor on the forward stroke 18. The diagram shows only the channels extreme lines of the photosensitive matrix.

Lens 19 transfers the image to the optical image divider 2, arrives; it onto the photosensitive recorder 1 and the photosensitive matrix, the plane of which is rotated relative to the plane of the lens perpendicular to the rows of the matrix, so that the image is focused on the photosensitive recorder on the matrix

the image is focused only for the middle row of photosensitive elements. At the edges of the matrix, the image is out of focus, with cry to achieve focusing on the photosensitive elements of the upper part

matrix lens must be moved to the left, and

in order to achieve focusing of the image on the photosensitive elements of the lower part of the matrix, it must be moved outwardly. The photosensitive elements of the matrix through amplifiers 7 are connected to the circuit 8 of forming a difference signal focusing the rows of the photosensitive matrix. These circuits are connected via switching valves 9 to capacitive accumulators of 10 differential signals, which are used alternately on alternating cycles. Drives are connected to a voltage difference amplifier 12 on accumulators, which, in turn, through output switching valves 14, controlled by a clock unit 6, are connected to majority elements 15, 16 connected to electric drive control relay 17, 18. Signals from the photosensitive elements of the matrix are fed through amplifiers 7 to the circuits 8 of forming differential signals for focusing the rows of the photosensitive matrix.

The differential signals through the valves 9 are fed to capacitive drives 10, 11 of even and odd cycles, respectively, where they are recorded for one cycle.

When the lens moves along the focusing thread, the difference signal of any of the lines in each subsequent cycle differs from such a signal at the time of the previous cycle. If the focusing becomes apparent, the differential voltage increases, if the focusing deteriorates, the differential voltage decreases. The difference of these voltages for the two subsequent cycles in time shows in which direction the lens moves in relation to this line.

So that the output of amplifier 12 does not depend on the parity of the clock, simultaneously with switching the input drives 10, 11, the outputs of this amplifier are switched. If the lens moves from left to right, precise focusing is ensured when the area of the matrix located above the focusing plane (to the right of the center line) forms a difference. The signal weakens as the lens moves, the area of the photosensitive matrix located to the left of the centerline forms the difference signal amplified as the lens moves, and the middle part of the matrix gives a constant signal.

Then the major elements 15 controlling the forward stroke of the engine and the elements 16 controlling the reverse stroke switch to the "O" state (no predominance of 5 is the number of inputs including one or the other element), and the engine stops.

Fundamentally, for the operation of the system, it would be sufficient to have a matrix of three light-sensitive lines, one of which was

0 would be closer to the focusing plane, a friend - farther than it, and a third would lie in this plane. However, in order for the system to be stable with different statically inhomogeneous images, it is desirable to have a large number of lines. This makes it possible to simultaneously increase the accuracy of focusing on different areas, with close or distant objects. This purpose is also served by sensor 4, which changes the frequency of the clock

0 commutation 6 depending on the position of the lens on the focusing thread. When the system is turned on, the forward code relay 18 or reverse relay 17 is turned on, depending on the ratio of the difference signals at the edges of the photosensitive matrix. For this, the analog outputs of the amplifiers 12 signals of the outermost rows of the photosensitive matrix are connected to the comparison circuit 13, which includes one of the relays.

Subject invention

An automatic lens focusing device containing a lens holder

5 with an electric drive associated with a control unit, a beam splitter, a photodetector array, and a signal generation unit, characterized in that, in order to increase accuracy and speed, the photosensitive0 surface of the photodetector matrix is rotated relative to the focal plane of the objective in a plane perpendicular to the rows of the matrix, and the electric drive is equipped with a lens position sensor, one of the parallel outputs of which is switched to the inputs of controllable gates of the forming unit through the clock switching unit and the other is connected to the inputs of the switching valves of the signal amplifiers, the outputs of which are connected via a coincidence circuit with the drive actuation relay.

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