JPS63318517A - Method and equipment for transmitting color image - Google Patents

Abstract

PURPOSE:To directly transmit a color image including color information only by one optical fiber as light itself by multiplexing respective image data of the three primary colors with the wavelength of light and transmitting the multiplied data. CONSTITUTION:White light projected from a light source 1 is radiated to a diffraction grating 3 by a lens 2, divided from single color beams respectively having wavelengths lambda1-lambdan and the divided single color beams are radiated to respective points corresponding to n picture elements on a reading face of a space optical modulator 5. On the other hand, three light sources 7R, 7G, 7B are periodically and alternately lighted by pulses and light dispersed from an object 6 forms its image on a reading face of the modulator 5. Image patterns projected from the object correspondingly to the dispersed beams of the three primary colors are converted into light intensity components having wavelengths lambda1-lambdan corresponding to respective picture elements and the beams are condensed by a lens 2'' and made incident upon an optical fiber 2. Consequently, two-dimensional color image information can be directly transmitted by one optical fiber 10 without being converted into an electric signal.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for transmitting color images over long distances using a single optical fiber and optical components.

(Prior art) As a method of directly transmitting image information in the form of light through an optical fiber without converting it into a time-series electrical signal, as in Japanese Patent Application No. 61-293477, there is a method of transmitting image information directly to each pixel of an image. A method is known in which lights of different wavelengths are matched and simultaneously transmitted through a single optical fiber. In this method, lights of different wavelengths are arranged two-dimensionally, and the wavelengths and spatial positions of pixels are made to correspond one-to-one. Therefore, although it is possible to transmit image patterns using this method, it is difficult to transmit color information. Further, in the above invention, since there is no mechanism for relaying and amplifying the signal, it is difficult to transmit the signal over a distance of several kilometers or more due to the propagation loss of the optical fiber.

(Problems to be Solved by the Invention) The present invention was made against this background, and by improving the above method, it is possible to directly produce a color image including color information through a single optical fiber. The object of the present invention is to provide a method and an apparatus for transmitting optical signals over long distances by repeating and amplifying them while maintaining the optical state.

(Means for Solving the Problems) The present invention uses scattered light of three primary colors from an object that blinks alternately as writing light to a spatial light modulator, and also uses light from a light emitting source as a plurality of lights having different wavelengths. The light beams are divided into light beams, each light beam is arranged two-dimensionally, and the light beams are modulated by the write light as read light to the spatial light modulator, and this modulated light is
By focusing the light on one end of the optical fiber, the image data of each of the three primary colors is multiplexed and transmitted by the wavelength of the light, and then the light emitted from the other end of the optical fiber is transmitted with the same number of wavelengths as the input side. A color image of an object is transmitted by dividing the light beam into components, using each light beam as a writing light of a spatial light modulator, and modulating the writing light with alternating blinking light of three primary colors as readout light. In addition, in amplification, the light emitted from the propagating fiber is divided into the same number of wavelength components as on the transmitting side.
The light beams are arranged in the same manner and irradiated onto the spatial light modulator as writing light having an original image pattern, while a plurality of high intensity light beams having different wavelengths are made to correspond to each pixel of the spatial light modulator. read out.

In terms of equipment, the transmitter includes a Kuzu optical system that uses the three primary colors of the object as writing light, and a system that divides the light from the light source into multiple light beams with different wavelengths and arranges each light beam two-dimensionally. a spatial light modulator that modulates the reading light with the writing light; and an optical system that focuses the modulated light onto an optical fiber; an optical system that divides light emitted from a fiber into a plurality of light beams with different wavelengths and arranges each light beam two-dimensionally as writing light; an optical system that uses three primary color lights as read light; The device includes a spatial light modulator that modulates read light with the write light, and an optical system that forms an image of the modulated light.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of the first embodiment of the present invention, in which 1 is a light source, 2.2', 2'', 2'' are lenses, 3.3' is a diffraction grating, and 4.4' is a A fiber bundle in which a plurality of optical fibers are arranged one-dimensionally (linearly) at one end and two-dimensionally at the other end, 5 is a spatial light modulator, 6 is an object to which the image is to be sent, and 7R.

7G and 7B are light sources that emit red, green, and blue light, respectively; 1
0 is an optical fiber.

Next, the operating principle will be explained.

First, white light emitted from a light source 1 such as a xenon lamp is irradiated onto a diffraction grating 3 by a lens 2, and the wavelength is changed from λ1 to λ.
It is divided into 7 monochromatic lights. These 0 lights, each having a different wavelength, are incident on the 0 optical fibers arranged in a horizontal row of the fiber bundle 4 in a one-to-one correspondence using a lens. Since the other end of the fiber bundle 4 has a two-dimensional shape, zero lights with wavelengths from λ1 to λ are arranged two-dimensionally and correspond to n pixels on the readout surface of the spatial light modulator 5. Each point is irradiated.

On the other hand, the object 6 is illuminated through the lens system by three light sources 7R, 7G, and 7B. At this time, the light sources are not turned on simultaneously, but are periodically and alternately pulsed.

The light scattered from the object 6 is imaged by the lens on the writing surface of the spatial light modulator 5, and at one time a scattered image is formed by red light, and at the next time a scattered image is formed by green light. However, at the next time, a scattered image of the three primary colors of light is periodically formed on the writing surface of the spatial light modulator 5, such as a scattered image of the blue light.

Therefore, the light from the fiber bundle 4 that is incident on the readout surface of the spatial light modulator 5 is modulated for each pixel at each time by the image of the scattered light from the object of the three primary colors. As the spatial light modulator 5, for example, a liquid crystal light valve as shown in FIG. 3 can be used. In FIG. 3, 21 is a liquid crystal layer, 22 and 22' are transparent electrodes, 23 is a photoconductive layer, 2j is a reflective film, 25 is a glass substrate, and 26 is a polarizing film. Since the voltage applied to the liquid crystal layer is small in areas where the writing light does not strike, the polarization direction of the reading light is rotated by 90 degrees as it travels back and forth through the liquid crystal layer, so it is not reflected. On the other hand, the resistance of the photoconductive layer decreases in the area that is hit by the writing light.
Since a voltage is applied to the liquid crystal layer, the polarization direction of the read light does not change and the read light is reflected.

The image pattern imaged by the writing light in this manner can be read out by the reading light having a wavelength different from that of the writing light. Furthermore, even if the writing light is weak, reading with strong light means that the pattern light has been amplified.

By the function of the spatial light modulator described above, the image pattern corresponding to the three primary colors of scattered light from the object is converted into the intensity of light from λ to λ7 corresponding to each pixel from the fiber bundle 4, and this light is The light is focused onto the optical fiber 10 by a lens and enters the fiber.

The image pattern corresponding to red, green, and blue from the object becomes light with n wavelengths corresponding to the pixels, which simultaneously propagate within the fiber for each color and are emitted from the other end.

This emitted light is split into a single beam with a wavelength of λ1 to λ7 using a lens 2'''' and a diffraction grating 3', and is incident on the linear end of a fiber bundle 4' that is exactly the same as the optical fiber bundle 4. An image pattern corresponding to the three primary colors is taken out from the two-dimensional end face of the end.The image pattern light corresponding to the three primary colors is irradiated onto the spatial light modulator 5' as writing light.

On the other hand, there are three light sources 7R' on the back of the spatial light modulator 5'.
, 7G', and 7B' are periodically and alternately irradiated with red, green, and blue light as readout light. Therefore, if the order of the colors of this readout light is synchronized with the writing light of the image pattern corresponding to the three primary colors, the image pattern of the three primary colors will be reconstructed. This reconstructed image pattern can be viewed by being projected onto the screen 8, for example.

If the temporal period of the three primary color patterns is set to 100 Hz or more, color moving images can also be transmitted. Note that the timing of the flashing cycles of the three primary colors of light on the transmitting side and the three primary colors of light on the receiving side can be synchronized by sending a start pulse at the beginning of transmitting an image.

Figure 2 shows one white light source 7 instead of using three light sources.
', 7'' and color filters 9 and 9' are shown. The disc-shaped color filter 9 is divided into three parts that transmit red, green, and blue rays, and by rotating them, the spatial The writing light (on the transmitting side) or the reading light (on the receiving side) to the optical modulator 5 is periodically made into light beams of three primary colors.The configuration and operation are the same as in FIG. 1 except for the above-mentioned parts.

Next, a method for amplifying and relaying image signals will be explained with reference to FIG. In FIG. 4, 31 is a light source, 32 is a lens,
33.33' is a diffraction grating, 34.34' is a Fido bundle in which a plurality of optical fibers are arranged one-dimensionally (linearly) at one end and two-dimensionally at the other end, 35 is a spatial light modulator, 38 is a half mirror. The image signal that has propagated within the optical fiber 10 is split again into one light beam with wavelengths λ8 to λ7 using the lens 32 and the diffraction grating 33', and enters the linear end of the optical fiber bundle 34', and the other end. 2 from the two-dimensional end face of
The light is arranged dimensionally and written into the spatial light modulator 35.

On the other hand, the white light emitted from the light source 31 is irradiated onto the diffraction grating 33 by the lens 32, and is split into monochromatic lights with wavelengths λ1 to λ7, which are transmitted through the fiber bundle 34 and are transmitted from λ to λ.
One beam of wavelength 7 is reflected by the half mirror 38 and irradiated to each corresponding point of the n pixels on the readout surface of the spatial light modulator 35. This read light is modulated by the image pattern of the write light and reflected, then passes through the half mirror 38, is focused by a lens, and propagates within the optical fiber 10'. In this process, if the intensity of the read light is made sufficiently stronger than the intensity of the write light,
This means that the image signal has been amplified.

(Effects of the Invention) As explained above, in the present invention, two-dimensional color image information can be directly transmitted through a single optical fiber without converting it into an electrical signal, and the image signal can be transmitted along the way. Since it can be amplified, long-distance transmission is also possible. Furthermore, the device is composed only of optical components such as lenses, diffraction gratings, and spatial light modulators, and has the advantage of being able to transmit color moving images without the need for broadband electronic equipment.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing the configuration of an embodiment of the present invention. FIG. 3 is a diagram showing an example of a spatial light modulation element used in the present invention. FIG. 4 is a diagram showing the configuration of a relay section in the present invention. It is a diagram. ■...Light source 2.2', 2", 2-.
... Lens 3.3'... Diffraction grating 4.4'...
- Fiber bundle 5.5'...Spatial light modulator 6...Object 7.7'...White light sources 7R, 7R'...Light sources 7G, 7G' that emit red light
...Light sources 7B, 7B' that emit green light...Light sources 8 that emit blue light...Screen 9.9'...
・Color filters 10, 10'...optical fiber 21...
- Liquid crystal layer 22, 22'... Transparent electrode 23... Photoconductive layer 24... Reflective film 25... Glass substrate 26... Polarizing film 31... Light source 32
...Lens 33.33'...Diffraction grating 34, 34'...Fiber bundle 35...Spatial light modulator 38...Half mirror Patent applicant Nippon Telegraph and Telephone Corporation Fig. 2 q, q '--Filter Fig. 3 23--11 bias conductive layer 24--1 film 25--h' lath base 26-----bias bias layer 24----

Claims (1)

[Claims] 1. Scattered light of three primary colors from an object that blinks alternately is used as writing light to a spatial light modulator, and light from a light emitting source is divided into a plurality of light beams with different wavelengths, By arranging each light beam two-dimensionally, modulating it with the writing light as readout light to the spatial light modulator, and focusing this modulated light on one end of one optical fiber, three primary colors can be obtained. Each image data is multiplexed by optical wavelength and transmitted, and then the light emitted from the other end of the optical fiber is divided into the same number of wavelength components as the input side, and each light beam is used as the writing light of the spatial light modulator. Toshi, 3
A method of color image transmission, characterized in that a color image of an object is transmitted by using alternating flashing light of primary colors as read light and modulating it with the writing light. 2. The method for generating the three primary colors of scattered light from an object on the transmitting side and the three primary colors on the receiving side is characterized in that three light sources corresponding to the three primary colors are used, or a white light source and a color filter are used. A method of color image transmission according to claim 1. 3. The scattered light of the three primary colors from the object that flashes alternately is used as the writing light to the spatial light modulator, and the light from the light emitting source is divided into multiple light beams with different wavelengths, and each light beam is converted into two-dimensional light. The image data of each of the three primary colors is modulated by the writing light as readout light to the spatial light modulator, and the modulated light is focused on one end of one optical fiber. Writing light that multiplexes light at its wavelength and transmits it, divides the light emitted from the fiber that has propagated within the optical fiber into the same number of wavelength components as on the transmitting side, and aligns each light beam in the same way to form the original image pattern. On the other hand, a plurality of high-intensity light beams with different wavelengths are read out corresponding to each pixel of the spatial light modulator, amplified, and the light beams are further connected to another optical fiber. incident,
Next, the light emitted from the other end of the optical fiber is divided into the same number of wavelength components as the input side, each light beam is used as the writing light of the spatial light modulator, and the light that flashes alternately in the three primary colors is used as the readout light for the writing. A color image transmission method characterized by transmitting a color image of an object by modulating it with light. 4. The transmitter includes an optical system that uses the three primary colors of the object as writing light, and splits the light from the light source into multiple light beams with different wavelengths, and arranges each light beam two-dimensionally to generate readout light. a spatial light modulator that modulates the reading light with the writing light; and an optical system that focuses the modulated light onto an optical fiber; An optical system that divides light into a plurality of light beams with different wavelengths and arranges each light beam two-dimensionally as a writing light, an optical system that uses three primary color lights as readout light, and an optical system that uses the readout light as the write light. A color image transmission device comprising a spatial light modulator that modulates light, and an optical system that forms an image of the modulated light. 5. In the color image transmission device according to claim 4, the optical system that uses the three primary colors of the object as writing light includes three light sources of red, green, and blue that illuminate the object, and a light source that emits light from the object. A color image transmission device comprising: an optical system for imaging scattered light onto a spatial light modulator. 6. In the color image transmission device according to claim 4, the optical system that uses the three primary colors of the object as writing light includes a white light source that illuminates the object and three colors of red, green, and blue. A color image transmission device comprising a filter and an optical system for imaging scattered light from an object onto a spatial light modulator. 7. The transmitter includes an optical system that uses the three primary colors of the object as writing light, and a light emitting source that divides the light into multiple light beams with different wavelengths and arranges each light beam two-dimensionally to generate readout light. A spatial light modulator that modulates the reading light with the writing light, and an optical system that focuses the modulated light onto an optical fiber, and is installed in the middle of an optical fiber transmission line. The amplification unit splits the light emitted from the optical fiber into multiple light beams with different wavelengths, arranges each light beam two-dimensionally, and generates writing light. Divide each ray into two different rays.
The receiver comprises an optical system that is arranged dimensionally to produce readout light, a spatial light modulator that modulates the readout light with the write light, and an optical system that focuses the modulated light onto an optical fiber. The part consists of an optical system that divides the light emitted from the optical fiber into multiple light beams with different wavelengths and arranges each light beam two-dimensionally as writing light, and an optical system that uses three primary color lights as read light. 1. A color image transmission device comprising: a spatial light modulator that modulates the reading light with the writing light; and an optical system that forms an image of the modulated light.