RU2106672C1 - Device for conversion of video television images to holographic ones - Google Patents

Abstract

FIELD: optoelectronics. SUBSTANCE: device has electron-beam light modulator. Unit which forms object beam providing for conversion of image foreshortenings in sagittal plane from control signals coming from control signal unit is installed at modulator optical output. Object beam unit also generates signals designed to control light electron-beam modulator, laser and tape-transport mechanism on the basis of signals of foreshortening number code in frame and frame number coming to its input from video tape recorder. EFFECT: more effective conversion. 2 cl, 3 dwg

Description

 The invention relates to the conversion of video television images to holographic and can be used, in particular, in research in space technology.

 A device is known for converting video television images into holographic ones by obtaining a primary image on photographic film by photographing from a kinescope screen, followed by holography of two or more banners, described in a known work.

 Its disadvantage is the low quality of hologram images when converting video and television images to holographic and low labor productivity.

 There is also known a device for converting video television images into holographic ones, containing a video recorder connected in series, the video signal from which is fed to electronic optics, which modulates the electron beam, recording primary images on a monochrome film in vacuum, which are then holographic / prototype /.

 Its disadvantage is the low quality of hologram images when converting video television images to holographic, low labor productivity, as well as the presence of a complex technological process for recording primary images on photographic film in vacuum, followed by a "wet" photochemical processing process.

где
L - ширина голограммы, M_i - расстояние по оси от экрана электронно-лучевого модулятора до оптического центра цилиндрического выпуклого зеркала,
оптическая система из плоского и цилиндрического выпуклого зеркал сменяется при переходе на следующий ракурс изображения по сигналу, поступающему с блока управляющих сигналов на блок формирования объектного пучка, причем, сигнал кода номера ракурса в кадре и номера кадра с видеомагнитофона поступает на вход блока управляющих сигналов, обеспечивающего выработку управляющих сигналов для управления зеркалами блока формирования объектного пучка, записью и стиранием первичного изображений в электронно-лучевом модуляторе света, включением и отключением излучения лазера при записи многоракурсных синтезируемых голограмм по схеме Ю.Н. Денисюка и лентопротяжного механизма.This problem is solved in that the device for converting video television images into holographic contains a video recorder connected in series, the video signal from which is fed to electronic optics, which modulates the electron beam, providing recording of primary images that are holographic with a laser and dividing mirror on a film moving with a stop-and-tape drive , the recording of primary images is performed in an electron beam light modulator, at the optical output of a cat An object beam forming unit has been installed, which provides conversion in the sagittal plane of each i-th image angle angle θ _i , except θ _i = 0 the image width, as L _i = L • cosθ _i , in the optical system consisting for each i the first view of the image from a flat mirror and a cylindrical convex mirror with a radius R _i equal to

Where
L is the width of the hologram, M _i is the distance along the axis from the screen of the electron beam modulator to the optical center of the cylindrical convex mirror,
the optical system from a planar and cylindrical convex mirrors is replaced when switching to the next image angle by a signal from the control signal block to the object beam forming unit, and the signal of the angle number code in the frame and the frame number from the video recorder is input to the control signal block providing generating control signals for controlling the mirrors of the object beam forming unit, recording and erasing primary images in an electron beam light modulator, turning on by turning on and off the laser radiation when recording multi-angle synthesized holograms according to the scheme of Yu.N. Denisyuk and the tape drive.

 Analysis of the scientific and technical literature showed that there are no devices with the indicated set of features. Therefore, the proposal meets the criterion of "novelty."

 In addition, the purpose of the invention is achieved by the entire set of essential features introduced, which is not found in the specified combination. Therefore, the proposal meets the criterion of "Significant differences".

Figure 1 presents a block diagram of the proposed device for converting video and television images into multi-angle synthesized holograms; figure 2 - the optical part of the device of figure 1 in sagittal section at an angle of incidence of the objective beam θ _i = 0 ^° . Figure 3 - the optical part of the device of figure 1 in sagittal section at an angle of incidence of the object beam θ _i = -30 ^° . .

 The device comprises a series-connected video recorder 1, a control signal unit 2, an electron beam light modulator 3, a laser 4, a dividing mirror 5, a polaroid divider 6, an object beam forming unit 7, a film 8, a tape drive 9, a reflective mirror 10. In addition , the components of the electron beam light modulator 3 are shown, such as: the electronic optics 11 of the recording electron gun 12, the screen 13, the fluorite substrate 14, the electronic optics 15 of the erasing electron gun 16. The composite ele Cops of the unit 7 of forming the object beam: flat mirrors 17i and cylindrical convex mirrors 18i, combined into an optical system 19i. Here i = 1, 2, ... n, where m is the number of angles recorded on the hologram. Laser beams are indicated by the numbers 20 - 25, the reference beam 27 and the object beam 18i.

 Elements 1 to 10 are standard electronic devices. A mass multi-track video recorder 1 is used. Block 2 of the control signals is built on standard electrical solutions using widely applicable radio elements. The electron-beam modulator 3 of light is a serial device of optoelectronics, for example, such as "Titus". The principle of operation is described, for example, in the book. Vasilieva A.A., Casasenta D., Kompanetsa I.N., Parfenova A.B., Spatial Light Modulators, Moscow: Radio and Communications, 1987, p. 53-58. Laser 4 is a powerful single-mode laser manufactured by the industry. Dividing mirror 5 is a partially transparent mirror. Polaroid divider 6 is an optical device, the principle of which is described, for example, in the book. Lansberg G.S., Optics, Moscow: Nauka, 1976, p. 479, p. 516. Block 7 of the formation of an object beam is an optomechanical device built on standard technical solutions described, for example, in the book. Lansberg G.S., Optics. M .: Nauka, 1976, p. 284. As a film 8, a specialized film is used for recording holograms on built-in interfering triggers, for example, of the FP-GT type. Its characteristics are presented in the book. Zhurby Yu.I., Quick reference to photographic processes and materials. M .: Art, 1991, p. 97. As a tape drive mechanism 9, a commercially available mechanism for the startotopic movement of film is used. Reflective mirror 10 is generally applicable.

 The device operates as follows.

 From the VCR 1, the video signal is fed to the electronic optics 11 of the recording electron gun 12 and modulates its electron beam. This electron beam writes on the crane 13 an electronic image of the object in the form of a distribution of options on its surface.

 The screen 13 is made of an electro-optical single crystal of potassium dideuterophosphate (DKDP), which has an induced birefringence from the charge of an electron beam. The crystal is cut by a Z-cut. A laser beam 23 having linear polarization, a dividing mirror 5, a polaroid divider 6, and a screen 13 pass from the laser 4. Then it is reflected from the fluorite substrate 14 and moves in the opposite direction in the form of a laser beam 24. A plane-polarized laser beam 23 passing twice through an DKDP crystal screen 13, is converted into two coherent waves: ordinary and extraordinary, propagating at different speeds. These waves, due to the birefringence of the crystal, acquire a phase difference determined by the surface charge of the electronic image on the screen 13. Since the vibrations in these waves are mutually perpendicular, they lead to the formation of elliptically polarized light in the laser beam 24. Polaroid divider 6 has a crossed polaroid and therefore, only an extraordinary wave passes through it, forming the image of the object.

Здесь
M_i - расстояние от оптического центра S по оси до точки D, т.е. SO + OD.Next, the laser beam 25 enters the block 7 of the formation of the object beam 28i. When recording a multi-angle synthesized hologram, the object beam 28i of each i-th image angle has a certain angle of incidence θ _i on film 8 and a certain image width CB at the point M of the intersection of the optical axis MS with film 8. We denote it as CB = L _i . We denote the width AE of the hologram frame by EA = L. Then from ΔACM and ΔMEB the image width L _i will be
L _i = L cosθ _i (1)
The angle of incidence θ _i and the image width L _i have a certain value for each I-th angle. Changing these parameters from perspective to perspective is performed in block 7 of the formation of the object beam 28i by command from block 2 of the control signals. Optical conversion of the laser beam 25 is performed using a planar mirror 17i and a convex cylindrical mirror 18i. A flat mirror 17i performs a change in the direction of the laser beam 25 by an angle of 2 α _i , thereby converting it into a laser beam 26i. The convex cylindrical mirror 18i rotates the laser beam 26i through an angle of 2 φ _i and performs the necessary change in width in accordance with dependence (1), turning it, thereby, into a laser beam 28i. The convex cylindrical mirror 18i forms an imaginary image of the angle. Its radius is determined from the mirror formula (see, for example, Prince G. Lansberg, Optics. M .: Nauka, 1976, p. 284, formula 72.5) as

Here
M _i is the distance from the optical center S along the axis to point D, i.e. SO + OD.

As can be seen from dependence (2), when passing from the i-th view to the (i + 1) -th view, the radius of the convex cylindrical mirror 18i changes. Therefore, in the block 7 for generating the object beam 28i, another convex cylindrical mirror 18i + 1 is included in the optical circuit with its values R _{i + 1} and φ _{i + 1} . In addition, for structural reasons, it is necessary to change the angle α _{i of the} inclination of the plane of the mirror 17i. Therefore, the mirrors 17i and 18i are combined into a single optical system 19i, which is individually included when recording the i-th image angle. This ensures that the nth number of angles is recorded in the range of angles θ _i from -90 ^o to +90 ^o . The reference beam 27 is formed from the laser beam 22 using a reflective mirror 10. The object beam 28i interferes with the reference beam 27 in the plane of the film 8. The interference field exposes the photo layer and holograms form on it after chemical-photographic processing of the film.

In block 2 of the control signals, control commands are generated that are sent to the electron beam light modulator 3 for controlling the recording and erasing of images on the screen 13, to the laser 4 for turning it on for the duration of the exposure of the hologram, to the tape drive 9 for the start-stop movement of the film to block 7 the formation of the object beam 28i by the angle of incidence θ _i and the width L _i by turning on the corresponding optical system 19i.

 In VCR 1, a magnetic tape with two tracks is charged. The video signal of the angle images is recorded on one track. On the other track, codes of the image angle number in the frame and the frame number on the film 8. are recorded. Based on these codes, the necessary control commands are generated in the block 2 of the control signals.

 As you can see, the proposed device is an automatic machine that converts video and television images into holographic ones. The magnetic tape carries the video signal and the necessary codes. In the process, the video signal is converted into multi-angle synthesized holograms, and the codes provide synchronous operation of the blocks of the proposed device.

We give numerical examples of an increase in the quality of multi-angle synthesized holograms. The main dependence characterizing the quality of perception is considered to be a linear dependence of the amount of information received by the visual analyzer of the operator on the recognition time t. This relationship is described in detail in kg. Glezer V.D., Vision and thinking. L .: Nauka, 1985, p. 155. The average amount of information received over a given time of presentation to the operator is found as
J = H (x) + H (y) - H (x, y).

Here
H (x) = -Σ P (x) log P (x) is the entropy of the probability distribution P (x) of the represented images, H (y) = -Σ P (y) log P (y) is the entropy of the probability distribution P (y ) of operator responses, H (x, y) = -Σ P (x, y) log P (x, y) is the entropy of the probability distribution of the joint occurrence of the operator’s answer Y and image X. These values are calculated from the matrices whose inputs are presented images and operator responses.

 From the dependence (3) it follows that to identify the object, the operator must receive a certain amount of information. The more information will be presented to the operator, the faster he will recognize the object. This dependence is approximated as linear. If the mono image recognition time is taken as unity, then for an n-angle image the object recognition time will be about 1 / n, i.e. the recognition time of an object is shorter, and accordingly, it is more likely that it is correctly identified and it is perceived by the operator as of higher quality.

 We show that the proposed device has a greater productivity compared to devices taken as a prototype and analogue. The last two devices have “wet” chemical-photographic processing upon receipt of primary images. This is a very big drawback in mass and mass production, because significantly reduces labor productivity. The proposed device does not contain a "wet" process. The primary image is recorded on the screen 18 of the electron beam modulator 3 of the light and after holography is wiped. In addition, it is fully automated. The codes of the image angle in the frame and the frame number on the film 8 contained on the magnetic tape of the VCR 1 completely control the process of multi-angle synthesized hologram recording, i.e. make the proposed device fully automated. Such a device has, undoubtedly, greater productivity than analog and prototype.

 Industrial application of the proposed device relates to the field of converting video television images into holographic ones. In particular, it can be used in research in space technology when analyzing the situation on aircraft by operators located on Earth. In addition, it can be applied in research and practical works in situations where it is necessary to increase the recognition of objects by their images in various fields of science and technology.

Claims (2)

1. A device for converting video television images into holographic ones, containing a video recorder connected in series, the video signal from which is fed to electronic optics, which modulates the electron beam, recording primary images that are holographic with a laser and dividing mirror on a film moving with a stop-and-tape mechanism, characterized in that the recording of primary images is performed in an electron beam light modulator, at the optical output of which anovlen block forming the object beam, which provides conversion to the sagittal plane of each i-th view image by angle θ _i, except θ _i = 0, and the data width as L _i = Lcosθ _i in the optical system, consisting for each i-th view image from a flat mirror and a cylindrical convex mirror with a radius R _i equal to

where L is the width of the hologram frame;
M _i - the distance along the axis from the screen of the electron beam light modulator to the optical center of a cylindrical convex mirror,
the optical system from a flat and cylindrical convex mirror changes when switching to the next image angle by the signal from the control signal unit to the object beam forming unit, and the signal of the angle code in the frame and frame number from the video recorder is input to the control signal unit.  2. The device according to claim 1, characterized in that the control signal block provides signal generation for controlling the mirrors of the object beam forming unit, recording and erasing primary images in an electron beam light modulator, turning on and off laser radiation when recording multi-angle synthesized holograms according to the scheme Yu.N. Denisyuk and the tape drive mechanism.

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