JPH09233380A - Optical fiber type image scanning device - Google Patents

Abstract

(57) Abstract: An optical fiber type image scanning device capable of observing the surface of an object in a special environment where electronic equipment cannot be brought in. SOLUTION: The polygon mirror 10 that periodically changes the refraction angle of incident light p from the observation target surface M in the longitudinal direction of the observation target surface M, and the polygon mirror 10 is arranged in the lateral direction in which the light refracted by this is incident. The optical fiber array 20 is composed of a CCD line sensor 30 which receives light emitted from the optical fiber array 20 and converts the light into an electric signal. The optical fiber array 20 is composed of a large number of optical fibers 21.
1a are arranged laterally adjacent to each other, and the optical fiber 21
The optical fibers at the entrance end 21a and the exit end 21b are configured to have the same adjacency relationship.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber type image scanning apparatus which scans a surface to be observed in a vertical direction and a horizontal direction and converts the scanned image into an electric signal via an optical fiber.

[0002]

2. Description of the Related Art Generally, an image tube device, a CCD device or the like is used to convert an image on a surface to be observed into an electric signal. However, if the surface to be observed is in a special environment such as liquid, high temperature, high pressure, high radiation dose, corrosive gas, or in vivo, installing electronic devices in these environments may cause damage. There is a demand for a means for extracting an image signal outside the system without using electronic equipment.

As such means, conventionally, for example, a fiberscope using a quartz optical fiber has been used. This fiberscope consists of an optical fiber bundle in which a large number of optical fibers are bundled, one end of which is equipped with an objective lens, and the other end (eyepiece) of which is equipped with an eyepiece lens and a camera. The optical fiber bundle is configured such that the optical fiber bundles of the object side and the eyepiece side have the same adjacency relationship.

The objective lens side of this fiberscope is
For example, insert it in a special environment to face the surface to be observed, pull the optical fiber bundle out of the system, place the eyepiece in a normal environment, and connect an observation electronic device such as a CCD camera to the eyepiece. For example, in the optical fiber bundle, the adjacency relationship between the individual optical fibers is the same on the objective side and the eyepiece, so the image of the observation surface placed under a special environment does not deform under normal conditions. It can be converted into an electric signal by an electronic device that has been taken out and placed under a normal environment.

[0005]

However, the size and resolution of the field of view (frame) of this fiberscope are as follows:
It depends on the density and the number of optical fibers in the optical fiber bundle. To increase the resolution, it is necessary to reduce the diameter of each optical fiber to increase the cross-sectional density. The number of optical fibers must be increased accordingly. Therefore, in order to obtain a high resolution and a wide field of view, it is necessary to integrate a large number of extremely thin optical fibers in correspondence with the expansion of the field of view while maintaining the adjacent relationship between them, which causes a limit in manufacturing. . The present invention has been made to solve the above problems, and therefore an object thereof is to expose an electronic device to a special environment without
Moreover, it is an object of the present invention to provide an optical fiber type image scanning device capable of obtaining an image having a high resolution and a wide field of view as an electric signal.

[0006]

In order to solve the above-mentioned problems, the present invention is an apparatus for scanning an observation target surface in the vertical direction and the horizontal direction to convert a scan image into an electric signal. A light refraction device that periodically changes the refraction angle of light incident from the vertical direction of the observation target surface, an optical fiber array in which light refracted by the light refraction device is incident, and an optical fiber array arranged in the lateral direction, A CCD line sensor that receives the light emitted from the fiber array and converts it into an electrical signal. The above optical fiber array is composed of a large number of optical fibers, and the incident ends of each optical fiber are arranged laterally adjacent to each other. And an optical fiber type image scanning device configured such that the adjoining relationship between the optical fibers at the entrance end and the exit end of each optical fiber is the same.
Here, the “vertical direction” and the “horizontal direction” are used to relatively distinguish one of the two directions orthogonal to each other on the observation target surface and the other.

In the above-mentioned optical fiber type image scanning apparatus, an objective lens for adjusting the focus and the image magnification is inserted between the observation target surface and the optical refraction apparatus or between the optical refraction apparatus and the optical fiber array. Preferably.
Further, a relay lens is inserted between the optical fiber array and the CCD line sensor to adjust the focal point and the optical path angle of the light emitted from each optical fiber of the optical fiber array so as to be incident on the CCD line sensor. It is preferable.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to specific examples. FIG. 1 shows an embodiment of the optical fiber type image scanning apparatus of the present invention. The device 1 is a device that scans the observation target surface M in the vertical direction and the horizontal direction and converts the scan image into an electrical signal. Basically, the refraction angle of the incident light p incident from the observation target surface M is basically adjusted. A polygon mirror (rotating polyhedron mirror) 10 that periodically changes in the vertical direction of the observation target surface M, an optical fiber array 20 arranged in the lateral direction to which light refracted by the polygon mirror 10 is incident, and this light CCD line sensor 30 that receives light emitted from the fiber array 20 and converts it into an electrical signal
It consists of

The surface M to be observed and the polygon mirror 10
The objective lens 41 for adjusting the focus and the image magnification is inserted between the optical fiber array 20 and the CCD line sensor 30, and the individual optical fibers 21, 21, 21 constituting the optical fiber array 20 are inserted between the optical fiber array 20 and the CCD line sensor 30. A relay lens 43 that adjusts the focal point and the optical path angle of the light emitted from the light source and makes the light incident on the CCD line sensor 30 is inserted.

The polygon mirror 10 is composed of a regular polygonal column (a regular octagonal column in this embodiment) whose axis X extends in the lateral direction, and the peripheral surface thereof is formed by mirror surfaces 11, 12 ,. Is a device configured to rotate around the axis X at a constant speed, and the device has a mirror surface 11, 12, ... The reflection angle (refraction angle) of the light p incident from the surface M via the objective lens 41 can be periodically changed in the vertical direction.

The above-mentioned optical fiber array 20 comprises a large number of optical fibers 21, 21, ...
1a, 21a, ... Are aligned in the lateral direction, and the adjoining relationships of the optical fibers at the incident ends 21a, 21a, ... And the outgoing ends 21b, 21b ,. Is configured. The optical fiber array 20 is the polygon mirror 10
Of the light reflected by the mirror surfaces 11, 12, ...
21a, ... Are arranged at positions where they can receive light. The optical fiber 2 used in the optical fiber array 20 in this embodiment
1, 2, 21, ... Are silica-based optical fibers having a core / clad structure and having both ends polished, and are capable of propagating light in a coherent state from an incident end to an emission end.

The CCD line sensor 30 described above is generally known, in which light receiving elements (not shown) are arranged in one direction, and these light receiving elements sequentially output the received light as electric signals. It is a device that can be converted into. In the present embodiment, in the CCD line sensor 30, each light receiving element thereof has each emitting end 21b, 21 of the optical fiber array 20.
, b, ... Are arranged so as to correspond to each other via the relay lens 43.

The apparatus 1 of the present embodiment has an objective lens 41, a polygon mirror 10 and an incident end 21 of an optical fiber array 20.
The probe head 1a including a, 21a, ... Is inserted into a special environment in which electronic equipment such as an electronic camera cannot be installed, and the objective lens 41 is made to face the observation target surface M under the special environment. When the focal length of the lens 41 is adjusted, the polygon mirror 10 is rotated in one direction at a constant speed, and the CCD line sensor 30 is activated, the observation target surface M is divided into squares without exposing the electronic device to a special environment. The image information in the frame is displayed by the CCD line sensor 3
It can be taken out as a sequential electric signal from 0.

The operation of the apparatus of this embodiment will be described with reference to FIG. In FIG. 2, the relay lens 43 is omitted. In FIG. 2, the observation target surface M
Is a frame divided into a rectangle having a vertical length of 1 and a horizontal length of m. In the device of this embodiment, since the relative positional relationship between the regular octagonal prism-shaped polygon mirror 10 and the optical fiber array 20 is fixed, the optical path P ₀ of the light incident on the incident end 21a of the optical fiber array 20 is , Is constant between the mirror surfaces 11, 12, ... Of the polygon mirror 10 and the incident end 21a.

When the polygon mirror 10 rotates and one of its mirror surfaces 11 begins to cross the optical path P ₀ at the position A, the light entering the optical fiber array 20 uses the optical path P ₀ as a reflected optical path and the mirror surface 11 ( The angle α between A) and the optical path P _0
1 is an incident light p ₁ to the mirror 11, reflecting angle. The incident light p ₁ is produced by refracting the light emitted from the lateral line image (m ₁ ) on the observation target surface M at the position represented by reference numeral m ₁ by the objective lens 41. Is.

Since the mirror surface 11 and the optical fiber array 20 have a width corresponding to the length of the line image m ₁ refracted by the objective lens 41, the light emitted from each point of the line image m ₁ is , Is refracted by the objective lens 41, is reflected by the mirror surface 11 (A), and is split and simultaneously incident on the respective optical fiber entrance ends 21a, 21a, ... Of the optical fiber array 20.

Since the respective light receiving elements 31 of the CCD line sensor 30 correspond to the respective emitting ends 21b of the optical fiber array 20, the optical fiber incident end 21 is formed.
The light from the line image m ₁ which is divided into a, 21a, ... Is incident from the respective emission ends 21b, 21b, ... (via the relay lens 43) while maintaining the respective adjacent relations. Are simultaneously incident on the light receiving elements 31, 31 ,. The CCD line sensor 30 includes the light receiving elements 31, 3
The light that is simultaneously incident on 1, ... Is converted into electric signals that are sequentially output at a constant cycle.

The polygon mirror 10 rotates and the mirror surface 11
When the light beam crosses the optical path P ₀ at the position of B, the light incident on the optical fiber array 20 uses the optical path P ₀ as a reflected optical path,
It is incident light p ₂ on the mirror surface 11 (B) having a reflection angle at an angle α ₂ formed by the mirror surface 11 (B) and the optical path P ₀ . This incident light p
_2, the observation target plane M, in which light emitted from the side of the line image at the location represented by reference numeral m ₂ (m ₂₎ is effected is refracted by the objective lens 41.

Therefore, the light emitted from each point of the line image m ₂ is the same as the light from the line image m ₁ and is the mirror surface 11.
From (B), the optical path P ₀ , the incident end 2 of the optical fiber array 20.
1a, 21a, ..., Emitting ends 21b, 21b ,.
The light is incident on the light receiving elements 31, 31, ... Of the CD line sensor 30 at the same time. The CCD line sensor 30 converts the lights that are simultaneously incident on the respective light receiving elements 31 into electric signals that are sequentially output at a constant cycle.

Generally, the maximum reflection angle (α ₁ ) and the minimum reflection angle (α ₂ ) of the mirror surface 11 are determined by the number of mirror surfaces of the polygon mirror 10 and the relative positional relationship between the mirror surface (11) and the optical path P ₀ . By rotating the polygon mirror 10 at a constant speed, the mirror surface 11 continuously changes the reflection angle α during one cycle from the maximum reflection angle (α _{1 in} FIG. 2) to the minimum reflection angle (α ₂ ). Then, during one cycle of the change of the reflection angle of the mirror surface 11, the frame (1 × m) of the observation target surface M is continuously scanned from the line image m ₁ to the line image m ₂ . As soon as the mirror surface 11 has finished traversing the optical path P ₀ , the adjacent mirror surface 12 will begin to traverse the optical path P ₀ , and the next scanning cycle will be repeated.

The image signal converted into an electric signal by the device of this embodiment can be displayed as an image on a TV device or the like. As shown in FIG. 3, this image is formed by two-dimensionally arraying pixel groups {d ₁ , d ₂ , ..., D _n , ...} On the display screen Y. This pixel array has an inclined one-dimensional pixel array {d ₁ , d ₂ , ..., D _n } having a pitch Q determined depending on the rotation speed and the number of mirror surfaces of the polygon mirror 10 and the cycle of the CCD line sensor 30. Will be sequentially accumulated in the vertical direction.

As for the resolution of the horizontal axis of the image obtained on the display screen Y, if the resolution of the display screen Y itself is ignored, the optical fiber array 2 with respect to the frame lateral width m of the observation target surface M.
0 depends on the number N of the optical fibers 21. Constant width m
On the other hand, if the number N of optical fibers is increased, the resolution on the horizontal axis is improved. At this time, it goes without saying that the array number of the light receiving elements 31 of the CCD line sensor 30 corresponds to the number N of optical fibers.

The vertical axis resolution of the image obtained on the display screen Y depends on the rotation speed and the number of mirror surfaces of the polygon mirror 10 and the cycle of the CCD line sensor 30. When the number of mirror surfaces is constant, the lower the rotation speed of the polygon mirror 10, the higher the vertical axis resolution. The shorter the cycle of the CCD line sensor 30, the higher the vertical axis resolution.

The number of mirror surfaces of the polygon mirror 10 is related to the vertical scanning length, that is, the vertical length 1 of the frame. The smaller the number of mirror surfaces, the larger the width of one-cycle specular reflection angle.
The vertical length l of the frame becomes longer. Therefore, when the rotation speed of the polygon mirror 10 and the cycle of the CCD line sensor 30 are constant, if the number of mirror surfaces is reduced, the vertical length 1 of the frame becomes longer, but the resolution of the vertical axis becomes lower. Practically, these numerical values are determined according to the resolution of the screen of the display device used, for example, by using a high-density TV device or the like so that the resolution on the display screen is 1000 vertical lines and 1000 horizontal lines. .

In the apparatus 1 of this embodiment, by moving the relative position between the exploration head 1a including the objective lens 41, the polygon mirror 10, and the objective side of the optical fiber array 20 and the observation target surface M, a wide target surface is obtained. Will be able to explore. At this time, if necessary, an illumination device using a light guide or the like can be disposed near the objective lens 41 to illuminate the observation target surface M. If an illuminating device is annularly arranged around the objective lens 41 to uniformly illuminate the inside of the frame of the observation target surface M, a shadowless image excellent in color discrimination and the like can be obtained. By illuminating the light beam, a shadow image can be obtained in which the unevenness of the observation target surface M can be enlarged and observed as a shadow. Further, the illumination light may be monochromatic light, infrared light, or ultraviolet light, if necessary.

In the above embodiment, the polygon mirror 10 is used as the light refracting device, but other than this, for example, a vibrating mirror device or a holographic grating device that changes the mirror surface angle at a constant period can be used. . The CCD line sensor 30 may be monochrome or color.

The objective lens 41 is for adjusting the focus and the enlargement (reduction) magnification when the image light in the frame (1 × m) of the observation surface M is incident on the incident end 21a of the optical fiber array 20. Therefore, if necessary, a single focus lens, a zoom lens, a turret type compound lens, or the like can be used. Also, since the vertical and horizontal enlargement (reduction) magnifications of the frames do not necessarily have to be the same,
As the objective lens 41, for example, a cylindrical lens or the like can be used. For example, if a cylindrical lens extending in the horizontal direction is used, it is possible to enlarge (reduce) only the vertical length 1 without enlarging (reducing) the horizontal length m of the frame. Further, the objective lens 41 may be used in combination with various optical filters.

An electric signal obtained by scanning the observation surface M using the optical fiber type image scanning device of the present invention is passed through a video amplifier, an A / D converter, an IC memory, a D / A converter and the like. The image can be displayed as an image on a display screen of a TV monitor, a projector, or the like, or can be transmitted to another image processing device, an automatic control device, an alarm device, or the like by wire, wireless, or optical communication to operate them. .

In the optical fiber type image scanning apparatus of the present invention, since the exploration head does not include an electronic device, it is placed in a special environment such as liquid, high temperature, high pressure, high radiation dose, corrosive gas, and in vivo. The observation target surface can be observed by inserting only the exploration head into this environment. Therefore, the optical fiber type image scanning device of the present invention can be advantageously used when observing and inspecting the surface condition of equipments and objects placed in special environments such as factories, mines, laboratories and hospitals. it can.

[0030]

The optical fiber type image scanning device of the present invention comprises:
A photorefractive device that periodically changes the refraction angle of incident light from the observation target surface in the vertical direction of the observation target surface, and an optical fiber array arranged in the lateral direction to which the light refracted by the photorefractive device is incident. , A CCD line sensor for receiving light emitted from the optical fiber array and converting it into an electric signal, wherein the optical fiber array comprises a large number of optical fibers, and the incident ends of the optical fibers are laterally adjacent to each other. And arranged so that the adjoining relationship between the optical fibers at the entrance end and the exit end of the optical fiber is the same, the observation electronic device can be isolated from the special environment, Moreover, an image with a high resolution and a wide field of view can be taken out as an electric signal.

In the above-mentioned optical fiber type image scanning apparatus, if an objective lens is inserted between the surface to be observed and the light refracting device or between the light refracting device and the optical fiber array, the focus and the image magnification can be increased. Since it can be adjusted, the range of correspondence to the observation target surface and its environmental conditions becomes wider.
Further, if a relay lens is inserted between the optical fiber array and the CCD line sensor, the focus and the optical path angle of the light emitted from each optical fiber of the optical fiber array are adjusted to accurately adjust the CCD line. Since the light can be incident on the sensor, it is possible to convert an optical image without bleeding into an electric signal with high accuracy.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the device of the present invention.

FIG. 2 is a perspective view showing one operation mode of the above embodiment.

FIG. 3 is a front view showing an example of an image obtained by using the above embodiment.

[Explanation of symbols]

1 ... Optical fiber type image scanning device, 1a ... Exploration head, 10 ... Polygon mirror, 11 (A), 11 (B)
...... Mirror surface, 20 ...... Optical fiber array, 21 ...... Optical fiber, 21 a ...... Optical fiber entrance end, 21 b ...... Optical fiber exit end, 30 ...... CCD line sensor, M ...... Observation surface, p ...... Injection light.

Claims (3)

[Claims] 1. A device for scanning an observation target surface in a vertical direction and a horizontal direction and converting the scanned image into an electric signal, wherein the refraction angle of light incident from the observation target surface is changed in the vertical direction of the observation target surface. A photorefractive device that changes periodically, an optical fiber array arranged in a lateral direction to which the light refracted by the photorefractive device is incident, and the light emitted from the optical fiber array is received and converted into an electrical signal. A CCD line sensor, the above optical fiber array is composed of a large number of optical fibers, the incident ends of the respective optical fibers are arranged laterally adjacent to each other, and the incident ends and the outgoing ends of the respective optical fibers are arranged. An optical fiber type image scanning device configured such that adjacent relationships between optical fibers are the same. 2. The optical fiber according to claim 1, wherein an objective lens for adjusting a focus and an image magnification is inserted between the surface to be observed and the photorefractive device or between the photorefractive device and the optical fiber array. Image scanning device. 3. A relay lens is inserted between the optical fiber array and the CCD line sensor to adjust the focal point and the optical path angle of the light emitted from each optical fiber of the optical fiber array so as to be incident on the CCD line sensor. The optical fiber type image scanning device according to claim 1.