JPS5934513A - Image transmitter using optical fiber - Google Patents

Abstract

PURPOSE:To transmit an image directly through a stepwise refractive index optical fiber which has only one circular core by rotating the 1st and the 2nd slits which extend radially from a center of rotation synchronously. CONSTITUTION:A light beam emitted from one point P in an image is incident to the core 2 of the optical fiber 1 at an angle thetain to travel in the core 2 zigzag at an angle thetan, and a conic pattern Q of the light having an about angle thetaout is formed. Slits 4a and 5a are provided on the incidence and projection sides to allow the pattern to correspond to either of Q1 and Q2 specifically. For this purpose, the slits 4a and 5a are rotated around an axial line section while the same position relation is held, transmitting the whole image.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical field of the invention The present invention relates to a device for directly transmitting arbitrary images such as characters and images using an optical fiber, and particularly relates to a device for directly transmitting arbitrary images such as characters and images using an optical fiber. The present invention relates to an image transmission device having a basic configuration for optically directly transmitting an image using a fiber.

(2) Prior art and problems As a method for directly transmitting a two-dimensional or three-dimensional image to a remote location using an optical waveguide without converting it into an electrical signal, there are conventional methods that include (a) a method using a large number of optical fiber bundles;
b) A method using a distributed index optical fiber or rod is being considered. The former requires a large number of aligned fibers, and the latter has problems such as the refractive index distribution often deviating from the ideal value, making it difficult to transmit over a distance of 10 to 20 fibers or more. (3) Object and structure of the invention Therefore, an object of the present invention is to solve the problems of the conventional method described above, and to directly generate images by using a stepped refractive index optical fiber having only one circular core. The goal is to provide equipment that can transmit data to

In order to achieve such an object, the present invention utilizes two slits that are arranged near both ends of a single stepped-index optical fiber or rotated at a certain distance with a certain positional relationship between the two slits. Image transmission is achieved by limiting the image formed in the fiber to one radiation direction at a time.

(4) Embodiment of the Invention An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram of a general transmission mode of an optical fiber used in the present invention, and FIG. 2 is an explanatory diagram of the basic principle of an image transmission device according to the present invention. In both figures,
1 is a stepped refractive index optical fiber, 2 is the core, 3 is the cladding, 4 and 5 are slit plates, 4α and 5α (are the slits, one point on the P image, Q, Qs, and Q2 are the points on the point P, respectively. image, Z is the axis of the optical fiber 1, α is the axis Z
b is the position of the image Q on the axis Z, IN) θi is the incident angle of the ray emitted from the point P, θ is the propagation angle in A2, θ is the exit angle, ω represents the rotational speed of the slit plates 4 and 5.

In Fig. 1, the refractive index of the core 2 in the optical fiber 1 is uniform, and the core diameter and the refractive index difference between the core 2 and the cladding 3 are adjusted so that a large number of modes (the number of modes is indicated by N) can propagate. Form it. Further, as the light rays, natural light rays or light rays equivalent thereto are used.

A light ray emitted from a point P on the image enters the core 2 of the optical core (N) fiber 1 at an angle θin, and then propagates in a zigzag manner within the core 2 at an angle θ7.
Between θ♂2 and θ, (N), where Kl is the refractive index of the core 2.

θ, = θ Z? 1. There is a relationship nI N . Furthermore, inside the core 2, in addition to the above-mentioned light rays, there are also light rays that propagate in a spiral manner, so that (N) after exiting the optical fiber 1, the angle is approximately θ. A cone-shaped light pattern Q having , is formed. Therefore, one point P on the image does not become a point image, and as it is, it is impossible to distinguish other points on the image that exist on the circumference including point P'r centered on point α. Therefore, the image on the input side cannot be reproduced on the output side of the optical fiber.

Accordingly, in the present invention, as shown in FIG. The above problem is solved by characterizing the propagating light rays by the rotation angle position of the slit plate 4.5, that is, the positions of the slits 4α and 5cL.

At the output end of the optical fiber, only the meridional rays selected by the slit 4a are distributed in a cone shape and output, but this is separated by a 1.5 cL slit extending in the diametrical direction.
, that is, only the illustrated point Q1 or Q2 (note that either Q16 or Q2 is selected). This (N) holds true for any position of P on the meridian plane, that is, for all values of θh. Therefore, in order to form an image of any other point on the circumference including point P at the output end,
The slit 4α and the slit 5cL' in FIG. 2 may be rotated around the axis line while maintaining the same positional relationship, and by doing so, any one point on the image can be fixed to a specific point at the output end. This allows for the transmission of the entire image.

Next, an embodiment of the present invention will be described with reference to FIGS. 3 and 4.

FIG. 3 is an overall configuration diagram of an image transmission device according to an embodiment of the present invention, and FIGS. 4 (CL) and (b) are explanatory diagrams of a scanning mechanism centered on a slit plate. In both figures, ■ is a stepped refractive index optical fiber, 6 is the image screen to be transmitted, and 6 is the refractive index stepped optical fiber.
α is an image, 7 is an index mark indicating the reference position of the screen, 8 is a Fresnel lens, 9 and 10 are slit plates, 9cL and 10α are slits, 11 is a Fresnel lens, 12 is an image sensor, 12α is a received image, 13 is a A photodiode, 14 and 18 are clock sources, 15 and 19 are drivers, 16 and 20Fi pulse motors, 17 and 21 are slit plate rotation drive mechanisms such as gears,
2 represents the axis of the optical fiber, and ω represents the rotational speed of the slit plate 9.10.

As for the image on the image screen 6 in FIG. 3, the characters CAI are exemplified as the image 6α in FIG. 4(a). The light emitted from the image screen 6 containing this image 6α is focused on the input end of the optical fiber 10 by the Fresnel lens 8, but at one point in time, only the optical signal of the image area that can pass through the slit 9α on the slit plate 9 can be incident on the light 7 eyeper 1, the slit plate 9 rotates once, and the slit 9α finishes scanning the entire image imti6, thereby completing the transmission of the image 6α. Further, when the slit 9α scans the index mark 7, an index optical signal is generated and simultaneously enters the optical fiber 1.

An optical signal obtained by scanning these images and index marks with the slit 9α is transmitted through the optical fiber l and emitted from the other end.

The emission patterns of the optical signals of the image and the index mark each have a cone shape, as explained in FIGS. 1 and 2.

Of these, only the image signal is selected by the slit 10α of the slit plate 10, and the index mark signal is the output pattern of it, both of which are selected by the Fresnel lens 1.
1, it is converted into parallel rays.

As shown in FIG. 4(b), the image scanning light signal that has passed through the slit 10cL and the Fresnel lens 11 sequentially produces an image 6α (i.e. [A]) on the image sensor 12 as the slit 10a rotates. Form. On the other hand, the index mark signal is detected by the photodiode 13 and given to the driver 19 as a control signal for synchronizing the rotation of the slit plate 10 with the rotation of the slit plate 9.

The rotation start positions and rotation speeds of the slit plates 9 and 10 need to match (however, the rotation start positions do not necessarily have to match, and a method such as applying coordinate rotation electrically later) is required. ). In this embodiment, the peripheral edges of the slit plates 9 and 10 are gear-shaped to engage with the gears 17 and 21, respectively, and the gear ratios in the respective gear combinations are assumed to be the same. . Therefore, clock source 1
If the same motors 4 and 18, drivers 15 and 19, and pulse motors 16 and 20 are used, the slit plates 9 and 10 can be rotated at the same rotational speed ω.

In order to align the rotational positions of the slit plates 9 and 10, it is necessary to reset the slit plate 10 to the reference position when the photodiode 13 detects the index mark signal, or to set the slit plate 10 to the reference position in advance. Then, when the photodiode 13 detects an index mark signal, rotation may be started from the reference position. The embodiment shown in FIG. 3 is constructed based on the latter method. For example, driver 19
is provided with a flip-flop (not shown) that controls the supply of drive pulses to the pulse motor 20.
. This flip-flop is reset by the output of the photodiode 13, and is reset by a reference position signal indicating the reference position state of the slit plate 100. As long as the slit plate 10 is not in the reference position, the flip-flop continues to supply OK drive pulses to the pulse motor 2 in the set state. Therefore, the slit plate 10 continues to rotate and eventually reaches the reference position. When the reference position is reached, the reference position signal described above is generated to reset the flip-flop. As a result, the supply of drive pulses to the pulse motor 20 is stopped, so that the slit plate 1
0 means that it stops at the reference position. After the image transmission operation starts, when the photodiode 13 detects the arrival of the index mark signal, the flip-flop is set and the rotation of the slit plate 10 is started. In this way 1. Therefore, the rotational positions of the slit plates 9 and 10 can be matched.

Although the above-mentioned embodiment device uses a rotary scanning mechanism using a mechanical slit plate, it is possible to create an electrically equivalent slit using the PPI method used in radar etc. or digital data processing technology. It is possible to realize a rotary scanning mechanism.

Furthermore, as an image screen, Bunsei, optical film, C
R7 screen or the like can be applied, and photosensitive paper, photosensitive film, etc. can be used instead of the image sensor.

(5) Effects of the Invention As described above, according to the present invention, images in any form can be transmitted at low cost using a simple mechanism.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the transmission mode of an optical fiber, Fig. 2 is an explanatory diagram of the principle of the present invention, Fig. 3 is a configuration diagram of an embodiment device, and Fig. 4 (
3a, ) and 3b are explanatory diagrams of a scanning mechanism centered on a slit plate in the embodiment apparatus shown in FIG. 3; In the figure, 1 is an optical fiber, 6 is an image ==, 7 is an index mark, 8 and 11 are Fresnel lenses, 9 and 10 are slit plates, 12 is an image sensor, 13 is a photodiode, 14 and 18 are clock sources, 15 and 19 represent a driver, and 16 and 20 represent a pulse motor. Patent Applicant: Patent Attorney, New Technology Development Corporation, Fumihiro Hasegawa, T1 Diagram

Claims (1)

[Claims] one refractive index stepped optical fiber, first and second rotational scanning means each provided near both ends of the optical fiber and having slits extending in the radial direction from the center of rotation; and a means for synchronously rotating the second rotary scanning means, and the first and second rotary scanning means are configured to rotate with their centers of rotation aligned with the central axis of the optical fiber, and The first image is
The optical fiber is scanned optically by a rotary scanning means, and the optical scanning signal obtained by the first rotary scanning means is made to enter the optical fiber and extracted from the second rotary scanning means to reproduce the image. An image transmission device using optical fiber.