SU711599A1 - Device for sensing images from photographic film - Google Patents

Description

The invention relates to automating automatics and can be used to convert a transparent image of a film into a television video signal, for example, in television and television devices. Optoelectronic devices are known for converting a photographic image into a television signal} L. Line-by-line conversion of a photographic image is carried out by a traveling beam system. In known devices, the line frame is carried out by a traveling beam sensor across a moving film, the frame sweep occurs due to the movement of the photographic film. The closest in technical terms to the proposed technical solution is the well-known G4 device containing an optically coupled light source and collimator object, a drive for photographic film and photodetectors. Known scanning device has a low sensitivity and a high level of interfering noise at the output. The aim of the invention is to increase the signal-to-noise ratio. This circuit is achieved in the device by the fact that it contains a cylindrical mirror optically connected with the collimator lens, the axis of which coincides with the direction of motion of the film, the spectrum converter, subtraction units and delay elements, the output of one of which is connected to the first inputs of the subtractors and to one of the spectrum converters, the other inputs of which are connected to the outputs of the subtraction units, the second inputs of which are connected to the outputs of the delay elements, the inputs of which are connected to the corresponding pho by the receivers located on the focal axis of the cylindrical mirror, on the reflecting surface of which there are masks in the form of alternating dark and light rectangular stripes.

37

Mirror Reflection Factor

surface varies according to

generating function relation

Wopsha.

The block diagram of the device is presented

in the drawing. The device contains:

1- light source

2-coplimator lens,

3- film,

4- film drive,

5 - cylindrical mirror,

6 - opaque mask,

7,8, 9 - photodetectors,

10, 11, 12 - constant delay lines

13, 14 - subtraction blocks,

15 - analogue spectrum converter

The light source 1 is located i fe the focal plane of the collimator objective 2, designed to create a parachute beam. In this bundle of sveg there is a film 3 with a transparent image to be read; film 3 is continuously moved by a film drive 4 between the coplimator lens 2 and the cylindrical mirror 5. A mask 6 is applied to the reflecting surface of the cylindrical mirror 5, the Cylindrical mirror 5 is designed to focus the light flux on the line of photodetectors 7, 8, 9. The line of photodetectors 7,

8, 9, the axis of the cylindrical mirror 5 and one of the sides of the mask 6 are oriented in the direction of movement of the film.

The mask 6 consists of 2 x 2 nominal elements, the reflection coefficient of which M (i, j) is defined as:

M (at X.y, U) NM (j) --- "j where is a positive integer such that 2 is the number of nominal elements placed on the line;

j 1, ..., the number of the nominal element counted along the direction of movement of the film 3.1 1, ... 2

the number of the nominal element along the line:, (i), X / (j) - Walsh functions

 - order determined by the generating ratio

; . CVlzl p

. (2-ktp,

2d) M-1)

G f g / h m1) -

); X. is a natural number; Р - О or 1. The light flux modulated by each line of the mask b falls on a separate

99.4

a photodetector 7, 8, 9. Each of the photodetectors 7, 8, 9 converts a luminous flux proportional to the corresponding component

Walsh spectrum, into an electrical signal. The output of each of the photodetectors 7, 8, 9 is connected to the input of the corresponding delay line 10, 11, 12. In this case, the input of delay line 12 is connected to a photodetector that forms the zero component of the Walsh spectrum. Lines 10, 11, 12 delays are designed to delay the electric signal at a constant time. The output of each of the delay lines 10, 11, besides the constant delay line 12, is connected to the first inputs of the respective blocks 13, 14 of the subtraction {ha. No. second inputs of blocks 13, 14 subtraction filed an electrical signal from the output

line 12 delay; and. The outputs of the subtraction units 13, 14, as well as the output of the delay line 12 are connected to the separate inputs of the analogue spectrum converter 15, which performs the conversion of the com ™

Wopsch spectrum in the transparent video output signal.

The device works as follows. The light flux from the light source 1, directed by the collimator lens 2 onto the film 3, projects a transparent image onto the cylindrical mirror 5 with the mask 6 applied to it. Modulated by the mask 6, the flux of the cylindrical mirror 5 is focused on the photo line of the receivers 7, 8, 9. Cylindrical mirror 5 transforms a rectangular image into a line oriented along the direction of film movement. At the output of each photodetector 7, 8, 9 an electrical signal arises, the magnitude of which is proportional to the flow to it. Therefore, the output signals of the photodetectors 7, 8,

9 contain nepeMemn je components proportional to the Walsh spectrum components of the various rows of the transparent image. Yapr ation from the outputs of photodetectors 7, 8, 9 through lines 10, 11, 12

delays and subtraction blocks 13, 14 are fed to various inputs of the analogue spectrum converter 15. Due to the movement of the film, the optical image is stirred in mask 6 along the direction of the orientation of the cylinder of the mirror 5 and the photoperiod 7, 8, 9. The delay time of the electrical signal in each line 10, 11, 12 is delayed so that

Claims (4)

SUMMARY OF THE INVENTION A device for reading images from a film containing optically coupled light source and a collimator lens, a drive for film and photodetectors, characterized in that, in order to increase the signal-to-noise ratio, it contains a cylindrical mirror optically coupled to the collimator lens, whose axis Sov5 falls with the direction of motion of the film, the spectrum converter, the subtraction blocks and delay elements, the output of one of which is connected to the first inputs of the subtraction blocks and to one of the inputs 10 spectral converter, the other inputs of which are connected to the outputs of the subtraction units, the second inputs of which are connected to the outputs of the delay elements, the inputs of which are connected to the corresponding 15 photodetectors located on the focal axis of the cylindrical mirror, on the reflective surface of which we put masks in the form of alternating dark and bright rectangular stripes. 20 Sources of information taken into account in the examination 1. Varbansky A. M. Television. M., Communication, 1973, p. 353-355. 2. Bratslavets Π. F. et al. Space 25 television. M., Communication, 1973, p. 181. 3. Copyright certificate of the USSR No. 399092. cl. H 04 N 5/30, 1972. '4. British patent No. 1314770, CL. H 4 G, 1973 (prototype). TSNIIIPI Order 9015/38 Circulation? 51 Subscription Branch of PPP Patent, Uzhhorod, st. Project, 4