JPH0850251A - Optical parts for fiber scope - Google Patents

Abstract

PURPOSE:To provide optical parts for a fiber scope capable of effectively and easily shielding unnecessary rays of which the incidence on an image pickup element is the cause for an image defect. CONSTITUTION:These optical parts are constituted by adhering a glass substrate 18 which has the same shape as the shape of the exit surface of a prism 16 facing the image pickup element 12 and is formed with a vapor deposited light shielding film 17 for shielding the unnecessary rays at the peripheral edges to the exit surface described above and, therefore, the unnecessary rays,l13, l14 are reflected by the reflection surface at the exit surface of the prism 16 formed by the vapor deposited light shielding film 17 deposited by evaporation on the glass substrate 18 and are emitted outside the optical parts 11, by which the incident thereof on the image pickup element 2 is prevented and the formation of reflected ghost images on a screen is prevented. The accurate formation of the vapor deposited light shielding film 17 without requiring operations of high difficulty is possible and in addition, there is no more possibility of generating dust by peeling of coating materials like heretofore.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical system for a fiberscope such as an endoscope, and more particularly to a fiberscope for preventing an unnecessary light ray causing an image defect from entering an image pickup device such as a CCD. Regarding improvement of optical components.

[0002]

2. Description of the Related Art Conventionally, in a fiberscope such as an endoscope, light emitted from a light source is guided to the tip by an optical fiber to irradiate a detection target portion, and reflected light reflected from the inspection target portion is tipped. The light is received by the objective lens provided in the image pickup device, and the image of the inspection target portion is formed on the image pickup device 2 such as CCD through the optical component 1 shown in FIG. The image formed on the image sensor 2 is output to a display device such as a CRT display and displayed on the screen of the display device.

As shown in FIG. 3, the optical component 1 includes an optical low-pass filter 3 provided for preventing a false resolution phenomenon due to a high frequency component from the incident light side, and a color correction according to the photosensitivity of the image pickup device 2. Color correction filter for (color adjustment)
4, a light-shielding plate with black paint applied to a frame-shaped metal plate that blocks unnecessary incident light outside the field of view that is diffusely reflected by the inspection target part that causes image defects in the image sensor 5, and reflects the incident light Reflective prism that emits light to the image sensor 2
6 is integrated, and the light shield plate 5 is attached to the exit surface of the prism 6.
It is constituted by applying a light-shielding coating 7 in the shape of a frame that shields unnecessary reflected light that could not be completely shielded by and shields it from being emitted.

In FIG. 3, the light ray l1 is incident on the optical component 1, is reflected by the prism 6 and is emitted to the image pickup device 2 to form an image, but the light ray l2 is incident on the optical component 1 unnecessarily. The light is blocked by the shading plate 5 as a light beam and is a prism
Incident on 6 is prevented. Further, unnecessary incident light rays that cannot be completely shielded by the light shielding plate 5, for example, light rays l3 and l4 respectively enter the prism 6 and are reflected, but the light shielding paint 7
Is blocked as unnecessary reflected light by each
Incident on 2 is prevented.

[0005]

However, in the above-mentioned optical component 1, the unnecessary incident light rays l2 or the unnecessary reflected light rays l3, l4 are shielded by the light-shielding paint 7 applied to the light-shielding plate 3 or the exit surface of the prism 6. In particular, when the light-shielding paint 7 is applied to the exit surface of the prism 6, the light-shielding paint 7 must be applied accurately and evenly. There is a problem that an image defect is likely to occur, and the light-shielding paint 7 is peeled off due to a change in shape with the lapse of time and is displayed as dust on the screen.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical component for a fiberscope capable of effectively and easily blocking an unnecessary light ray which is incident on an image pickup device and causes an image defect. And

[0007]

In order to achieve the above object, the present invention provides a reflection type prism which reflects light incident from an objective lens provided on the front end side of a fiberscope and guides it to an image pickup device. In an optical component for a fiberscope having a glass substrate, which has the same shape as the exit surface of the prism facing the image sensor and has a vapor deposition light-shielding film that shields unnecessary reflected light rays at the periphery, is adhered to the exit surface of the prism. It is characterized by being

Further, the present invention provides an optical component for a fiberscope having a reflection type prism for reflecting light incident from an objective lens provided on the tip side of the fiberscope and guiding it to the image pickup device. It is characterized in that a vapor deposition light-shielding film for shielding unnecessary reflected light rays is formed on the periphery of the exit surface of the prism facing each other.

Further, the present invention is characterized in that a vapor deposition light-shielding film which shields unnecessary incident light rays is formed in a predetermined region of the incident surface of the prism.

Further, the present invention is characterized in that the vapor deposition light-shielding film is made of chromium.

[0011]

The optical component for a fiberscope of the present invention is a glass substrate which has the same shape as the exit surface of the prism facing the image pickup element and has a vapor-deposited light-shielding film formed on the periphery to shield unnecessary reflected light. Since the structure is adhered, unnecessary reflected light rays are prevented from entering the image pickup device, and the vapor deposition light-shielding film can be formed with high precision without requiring difficult work. Only the formed glass substrate can prevent unnecessary reflected light rays from entering the image pickup device.

Further, since the fiberscope optical component of the present invention has a structure in which a vapor deposition light-shielding film for shielding unnecessary reflected light rays is formed on the periphery of the exit surface of the prism facing the image pickup device, it has a simple structure. The unwanted reflected light rays are prevented from entering the image sensor, and the vapor-deposited light-shielding film can be formed accurately without the need for difficult work. Therefore, the vapor-deposited light-shielding film prevents unwanted reflected light rays from entering the image sensor. Is possible.

Further, since the optical component for a fiberscope of the present invention has a structure in which a vapor deposition light-shielding film is formed on a predetermined region of the entrance surface of the prism, it is possible to reduce the number of components to be configured.

Further, in the optical component for a fiberscope of the present invention, since the vapor deposition light shielding film is made of chromium, a stable vapor deposition light shielding film can be obtained.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic structure of an optical component for a fiberscope according to an embodiment of the present invention. In FIG.
Reference numeral 11 is an optical component.The optical component 11 guides light emitted from a light source in a fiberscope such as an endoscope to the tip by an optical fiber to irradiate the detection target portion, and then is reflected by the inspection target portion. The reflected light received by the objective lens provided at the front end is incident. Optical component 11
The light beam incident on is emitted to an image pickup device 12 such as a CCD via an optical component 11 and is focused on the image pickup device 12 as an image of a portion to be inspected. The image formed on the image sensor 12 is output to a display device such as a CRT display and displayed on the screen of the display device.

The optical component 11 is an optical low-pass filter 13 provided to prevent a false resolution phenomenon due to high frequency components,
A color correction filter 14 that performs color correction (color adjustment) according to the photosensitivity of the image sensor 12, and shields unnecessary incident rays outside the field of view that are diffusely reflected by the inspection target part that causes image defects in the image sensor 12. -Shaped metal plate coated with black paint and a light-shielding plate 15, and a reflection type prism 16 that reflects incident light and emits the reflected light to the image pickup device 12 are integrated, and further located near the image pickup device 12. As shown in FIG. 2, the glass substrate 18 made of the same material as the prism 16 having the same shape as the exit surface of the prism 16 and having the vapor-deposited light-shielding film 17 formed on the periphery of the prism 16 as shown in FIG. It is configured by being adhered to 16 emission surfaces.

The vapor deposition light-shielding film 17 is formed by vapor-depositing chromium or the like on the glass substrate 18 by a vacuum vapor deposition method.
Unwanted incident light rays that could not be shielded by 15 are reflected by the prism 16 to become unnecessary reflected light rays, which shields the reflected light emitted to the image sensor 12 and prevents the unnecessary reflected light rays from being emitted to the image sensor 12. That is, a reflection surface is formed by the vapor deposition light-shielding film 17 at a portion of the exit surface of the prism 16 that faces the vapor deposition light-shielding film 17 that is adhered, and unnecessary reflection light rays incident on this reflection surface are reflected to eliminate unnecessary reflection. Ray imaging device 12
Is prevented from being emitted.

Next, the operation of the optical component 11 having the above structure will be described.

The light ray 11 is a light ray within the field of view and is a light ray necessary for forming an image of the inspection target portion, and this light ray 11 is passed through the optical low-pass filter 13, the color correction filter 14, and the light shielding plate 15 to the prism 11. After being incident, it is reflected by the prism 11 and emitted as a necessary light beam to the image pickup device 12 via the glass substrate 18. The light beam 11 incident on the image pickup device 12 becomes a part of the image formed by the image pickup device 12.

On the other hand, the light rays l12, l13, and l14 are reflected by the image pickup element 12.
2 shows an unnecessary light ray outside the visual field, which is diffusely reflected by the inspection target portion causing the image defect in FIG. That is, ray l12
Is blocked by the light-shielding plate 15 as unnecessary incident light even if it is incident on the optical component 11 to prevent it from entering the prism 6, and unnecessary incident light that cannot be shielded by the light-shielding plate 15, for example, light rays l13 and l14. Respectively enter the prism 16 and are reflected, and these light rays l13 and l14 are reflected as unnecessary reflection light rays by the reflection surface at the exit surface of the prism 16 formed by the vapor deposition light-shielding film 17 vapor-deposited on the glass substrate 18. Are emitted outside the optical component 11 and are prevented from entering the image pickup device 2.

According to the above-described embodiment, the optical component 11 of this embodiment has a vapor-deposition that has the same shape as the emission surface of the prism 16 facing the image pickup element 12 and shields unnecessary reflected light rays at the periphery. Glass substrate 18 on which the light shielding film 17 is formed
The unnecessary reflected light l13,
ll4 is reflected by the reflection surface of the exit surface of the prism 16 formed by the vapor deposition light-shielding film 17 deposited on the glass substrate 18 and emitted to the outside of the optical component 11, whereby the respective light rays l13 and l14 are captured. Can be prevented from being incident on the screen, and formation of a reflected ghost image on the screen can be prevented. In addition, the vapor-deposited light-shielding film 17 can be formed with high precision without requiring highly difficult work.
Since the glass substrate 18 on which the vapor deposition light-shielding film 17 is formed is adhered, there is no possibility that dust is generated due to paint peeling as in the conventional case.

Further, since the vapor deposition light-shielding film of the optical component 11 of this embodiment is made of chromium, a stable vapor deposition light-shielding film 17 can be obtained.

Further, in the above embodiment, the vapor-deposited light-shielding film 17 is formed and formed by vapor-depositing chrome or the like on the glass substrate 18 and adhered to the emission surface of the prism 16. The vapor deposition light-shielding film 17 may be directly formed / formed on the periphery. With this configuration, the glass substrate 18 is not necessary, and the optical component 11 can prevent unnecessary reflected light rays from entering the image pickup device 12 with a simple configuration.

Further, in the above embodiment, the color correction filter 14
The light-shielding plate 15 is provided between the exit surface of the prism 16 and the entrance surface of the prism 16. However, chrome or the like is provided on the periphery of the exit surface of the color correction filter 14 or in a predetermined area of the entrance surface of the prism 16 facing the exit surface. Alternatively, the light-shielding film 17 may be directly formed / formed by vapor-depositing the light-shielding film. With this structure, the light-shielding plate 15 is unnecessary, and the optical component 11 has a simple structure and is an image sensor for an unnecessary reflected light beam. It is possible to prevent incidence on 12.

In the above embodiment, the color correction filter 14
And the glass substrate provided between the light shielding plate 15 and the prism 16
Although the vapor-deposited light-shielding film 17 vapor-deposited on 18 is also used to prevent unnecessary light rays (unnecessary incident light rays and unnecessary reflected light rays) from entering the image pickup element 12, the light shielding plate 15 is not used and the glass is used. The unnecessary light rays may be shielded only by the vapor deposition light-shielding film 17 vapor-deposited on the substrate 18. This is because the glass substrate 18 on which the vapor deposition light-shielding film 17 has been vapor deposited is located in the vicinity of the image sensor 12, so that there is no overlap between light rays entering the visual field and light rays departing from the visual field, and separation is facilitated. is there. At this time, the position (that is, the width) of the vapor deposition light shielding film 17 with respect to unnecessary incident light rays outside the visual field that are diffusely reflected by the inspection target portion that causes the image defect in the image pickup device 12 and the vapor deposition light shielding that separates the light rays entering and exiting the visual field. When the position (that is, the width) of the film 17 is compared and the optical system of the fiberscope including the optical component 11 is an optical system in which the two can be set equal to each other or the former can be set smaller, the vapor deposition light-shielding film 17 can be used with higher accuracy. Since the film can be formed and formed well, without using the light shielding plate 15,
It is possible to prevent unwanted light rays from entering the image pickup element 12 only by the glass substrate 18 on which the vapor deposition light-shielding film 17 provided on the exit surface of the prism 16 is vapor deposited, and it is possible to obtain a good image.

The present invention is not limited to the above embodiment, and can be variously modified.

[0028]

As described in detail above, the optical component for a fiberscope of the present invention is a vapor deposition device that has the same shape as the exit surface of the prism facing the image pickup element and shields unnecessary reflected light rays at the periphery. Since the glass substrate on which the light-shielding film is formed is adhered, it is possible to prevent unnecessary reflected light rays from entering the image sensor, and
Since the vapor deposition light-shielding film can be accurately formed without requiring a highly difficult work, it is possible to prevent unnecessary reflected light rays from entering the image pickup element only with the glass substrate on which the vapor deposition light-shielding film is formed.

Further, since the optical component for fiberscope of the present invention has a structure in which the vapor deposition light-shielding film for shielding unnecessary reflected light rays is formed on the periphery of the exit surface of the prism facing the image pickup device, it has a simple structure. Since it is possible to prevent unwanted reflected light rays from entering the image sensor, and the vapor-deposited light shielding film can be accurately formed without requiring difficult work, the image sensor for unnecessary reflected light rays can be formed only by the vapor deposited light shielding film. Can be prevented.

Further, since the optical component for a fiberscope of the present invention has a structure in which a vapor deposition light-shielding film is formed on a predetermined area of the entrance surface of the prism, it is possible to reduce the number of constituent components.

Further, in the optical component for a fiberscope of the present invention, since the vapor deposition light shielding film is made of chromium, a stable vapor deposition light shielding film can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of an optical component for a fiberscope according to an embodiment of the present invention.

FIG. 2 is a plan view of a glass substrate on which a vapor deposition light-shielding film is formed and formed.

FIG. 3 is a cross-sectional view showing a schematic configuration of a conventional optical component for a fiberscope.

[Explanation of symbols]

 11 ... Optical components (optical components for fiberscope) 12 ... Imaging element 16 ... Prism 17 ... Vapor-shielding film 18 ... Glass substrate

Claims (4)

[Claims] 1. A fiberscope optical component having a reflection-type prism that reflects light incident from an objective lens provided on the tip side of a fiberscope and guides the light to an image pickup device, wherein the prism faces the image pickup device. An optical component for a fiberscope, characterized in that a glass substrate having the same shape as that of the emission surface and having a vapor-deposited light-shielding film for shielding unnecessary reflected light rays formed on the periphery thereof is adhered. 2. An optical component for a fiberscope having a reflection type prism that reflects light incident from an objective lens provided on the tip side of the fiberscope and guides it to an image pickup device, wherein the prism is opposed to the image pickup device. An optical component for a fiberscope, wherein a vapor-deposited light-shielding film that shields unnecessary reflected light rays is formed on the periphery of the emission surface of the fiberscope. 3. The optical component for a fiberscope according to claim 1 or 2, wherein a vapor deposition light-shielding film that shields unnecessary incident light rays is formed in a predetermined region of the incident surface of the prism. 4. The optical component for a fiberscope according to claim 1, wherein the vapor deposition light-shielding film is made of chromium.