JP3042355B2 - Light source device for endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device for an endoscope capable of providing illumination light most suitable for a rigid endoscope, a fiberscope, a color mosaic type electronic scope, and a plane-sequential type electronic scope.

[0002]

2. Description of the Related Art In recent years, an endoscope capable of observing internal organs or the like by inserting an elongated insertion portion into a body cavity or performing various treatments using a treatment tool inserted into a treatment tool channel as necessary. Is widely used. Also, in the endoscope,
Roughly classified, there are a rigid scope and a fiber scope for visual observation, and an electronic scope using a solid-state imaging device such as a charge-coupled device (CCD) as imaging means. In such a method of capturing a color image of an electronic scope, for example, the illumination light disclosed in JP-A-61-82731 is sequentially switched to R (red), G (green), B (blue) and the like. A filter array in which color filters transmitting R, G, B, and other color lights are arranged in a mosaic pattern on the front surface of a solid-state imaging device disclosed in Japanese Patent Application Laid-Open No. Sho 60-76888. There is a color mosaic type (also called a simultaneous type).

In general, a rigid endoscope, a fiberscope, and an electronic scope are connected to a light source device capable of supplying illumination light suitable for each scope. The illumination method is different between the field-sequential electronic scope and the field-sequential type electronic scope. That is, the former requires white light,
In the latter, light that is sequentially switched to R, G, B, etc. is required. Therefore, it is necessary to prepare a specific light source device according to the type of the scope to be used, and it is necessary to perform different operations for each of the light source devices. So, to solve this problem,
For example, as described in JP-A-63-281117, a single unit supplies illumination light that is compatible with both a rigid endoscope, a fiberscope, a color mosaic type electronic scope, and a plane sequential electronic scope. There are endoscope light source devices that can be used.

However, in this light source device, since the light emitted from the light source includes a large amount of light in the infrared region in addition to light in the visible region necessary for observing an object, the light from the light source is collected. There has been a problem that the fiber end surface of the light guide that burns is burnt, and this light guide causes a problem. As means for solving this problem, for example, as described in JP-A-57-5020, an infrared absorbing filter is provided between a light source and a light guide, and the light guide is longer than the visible region. The light on the wavelength side is prevented from being incident, and the end face of the light guide fiber is prevented from burning. However, in this method, since only one infrared absorption filter is used, when lighting is performed for a long time, the temperature of the base of the infrared absorption filter increases due to the absorbed infrared light, and the thermal expansion generated due to this increases. The base of the infrared absorption filter itself cannot be tolerated and will be damaged.

In order to solve this problem, an infrared reflection type in which an interference film is provided on a transparent base between a light source and an infrared absorption filter as disclosed in Japanese Utility Model Laid-Open No. 3-51411 is disclosed. By arranging the interference filter, the light in the infrared region incident on the infrared absorption filter was reduced, and the light in the infrared region was blocked while the occurrence of thermal expansion was suppressed as much as possible to prevent breakage of the base. .

[0006]

However, in the above-mentioned infrared reflection type interference filter, light in the visible region is transmitted by 10%.
0% cannot be transmitted, and the light in the visible
% Is reduced. On the other hand, the infrared absorption filter absorbs not only infrared light but also light in the visible region, and reduces light in the visible region by about 20%.
Therefore, when two infrared reflection type interference filters and two infrared absorption filters are used, the amount of transmitted light in the visible region is considerably reduced. Further, when a field-sequential electronic scope is used, a field-sequential color separation filter is inserted in the optical path in addition to the infrared cut filter described above. Since this color separation filter sequentially separates and transmits white light into R, G, and B color lights, the brightness of the transmitted light is approximately equal to that when the color separation filter is not inserted in the optical path. It becomes 1/3. For this reason, when using the field sequential type electronic scope, there was a problem that the brightness as illumination light was insufficient.

Incidentally, since the fiber end face of the light guide is burned by the light in the infrared region emitted from the light source, it is necessary to block the light in the infrared region. That is, the fiber end face of the light guide has a considerably high energy density, which contributes to raising the temperature of the fiber end face of the light guide. Therefore,
When using a rigid endoscope, a fiberscope, or a color mosaic type electronic scope, light in the visible region is simultaneously focused on the end surface of the light guide fiber, so that the energy density of light in the visible region is increased and the end surface of the light guide fiber is increased. Temperature rises. For this reason, in order to reliably prevent burning of the end face of the light guide fiber, it is necessary to completely remove at least light in the infrared region.

On the other hand, when a plane-sequential type electronic scope is used, the white light emitted from the light source is sequentially separated into R, G, and B color lights and collected on the end face of the light guide fiber. Therefore, the energy density of light in the visible region at the end face of the light guide fiber is about 1/3 as compared with the case where the rigid endoscope, the fiberscope and the color mosaic type electronic scope are used. For this reason, the temperature of the end face of the light guide fiber does not rise so much,
Unlike the case of using a fiberscope and a color mosaic type electronic scope, the end face of the light guide fiber does not burn even if the light in the infrared region emitted from the light source is not completely removed.

However, any one of the above-mentioned scopes is used in a light source device which can supply illumination light suitable for all of the conventional rigid endoscope, fiber scope, color mosaic type electronic scope, and plane sequential type electronic scope. In the case of using, at least two or more infrared reflection type interference filters and infrared absorption filters are used to almost completely block the light in the infrared region. Unnecessary light in the infrared region was removed. As described above, when light in the infrared region is removed more than necessary, as shown in FIG. 4, light in the visible region to be removed also covers a considerable amount, and the brightness as illumination light is reduced. Loss. Further, in order to improve the brightness, it is not cost-effective to remove light in a wide band over the entire infrared region using only an interference filter.

In view of the above, the present invention has been made in view of the above-mentioned problems of the prior art, and it is an object of the present invention to provide a light-emitting device without causing problems such as breakage of an infrared absorption filter and burning of a light guide fiber end face. Illumination light suitable for any of a rigid endoscope, a fiberscope, a color mosaic-type electronic scope, and a plane-sequential-type electronic scope, in which brightness as illumination light does not become insufficient even when a sequential electronic scope is used. An object of the present invention is to provide an endoscope light source device that can be provided.

[0011]

SUMMARY OF THE INVENTION In order to solve the above problems, an endoscope observation device according to the present invention comprises a light source for emitting white light containing components in the visible and infrared regions, and at least a surface. In an endoscope light source device including a sequential color separation filter and an infrared cut filter that blocks light in an infrared region out of the wavelength region of the white light, the light source device may be disposed in an optical path from the light source to a light guide. and when the color separation filters are arranged, in the case where the color separation filter in the optical path is not disposed, the infrared
It is characterized in that the configuration of the line cut filter is different .

[0012] More specifically, the apparatus of the present invention comprises:
In the optical path from the source to the light guide, the color separation filter
If a filter is installed, the infrared cut filter
Luther is a group of interference filters with an interference film on a transparent base
And the color separation filter is disposed in the optical path.
If not installed, the infrared cut filter
Has at least an interference filter group and a wavelength in the infrared region
And a group of infrared absorption filters that absorb light
It is preferred that Here, the interference filter group is
Infrared reflection type filters, including interference filters
Wavelength region where the light transmittance at 5% is 5% or less
Is the plane-sequential rotary color separation at least on the short wavelength side.
Longer than the wavelength at which the light transmittance of the filter is 5% or less
On the wavelength side, and on the long wavelength side of the cut wavelength, an image sensor
Is on the longer wavelength side than the sensitive infrared wavelength range
preferable.

Further, in the apparatus according to the present invention, when the color separation filter is disposed in an optical path from the light source to the light guide, the infrared cut filter disposed in the optical path has a wavelength of 1100 nm or more. Is a group of filters configured to be able to transmit light having the following.On the other hand, when the color separation filter is not arranged in the optical path, the infrared cut filter is arranged in the optical path. Is light in the infrared region
In addition to light having a wavelength of 1100 nm or less,
The structure is such that light having a wavelength of at least nm can be sufficiently removed.
Preferably, the group of filters is formed. Further, the device of the present invention is a light source that emits white light containing components in the visible and infrared regions, at least a color separation filter of a plane-sequential type, and converts light in the infrared region out of light in the wavelength region of the white light. An endoscope light source device comprising an infrared cut filter group that blocks light, wherein the color separation filter is disposed in an optical path from the light source to a light guide, and the color separation filter is disposed in the optical path. in the case not, be interchangeably constitute a part or all of the infrared cutoff filter group arranged in the optical path
In the two cases, the infrared cut filter
It is good to make the composition of the key different .

Since the apparatus of the present invention is configured as described above, when a rigid endoscope, a fiberscope or a color mosaic type electronic scope is used, burning of the end face of the light guide fiber or breakage of the infrared absorption filter may occur. Such a defect does not occur, and the brightness as the illumination light can be sufficiently obtained. When using a plane-sequential electronic scope, white light emitted from the light source and containing both visible and infrared components is passed through the interference filter group, and is at least a component of light in the infrared region. Is removed, so that light having a wavelength equal to or less than the wavelength of the remaining light in the infrared region and light in the visible region is transmitted. The light that has passed through the group of interference filters is separated into R, G, and B light in the visible region by a plane-sequential color separation filter, and is condensed on the end face of the light guide fiber. At this time, although part of the light in the infrared region remains, the energy density at the end face of the light guide fiber due to light in the visible region is lower than when a rigid endoscope, a fiberscope, and a color mosaic type electronic scope are used. Since it is about 1/3, even if light in the infrared region partially remains, the end face of the light guide fiber does not burn.
Further, since only an interference filter is used to remove light in the infrared region, the decrease in light in the visible region can be suppressed to a small value.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments.

First Embodiment FIG. 1 shows the configuration of a light source device for an endoscope according to the present embodiment. FIG. 1A is a device configuration diagram when a plane-sequential type electronic scope is used, and FIG. It is a device block diagram at the time of using a rigid endoscope, a fiberscope, and a color mosaic type electronic scope.

When a plane-sequential electronic scope is used in the apparatus of this embodiment, first, as shown in FIG. A reflection type interference filter 2a is disposed, and a condenser lens system 3
A light guide 6 is arranged at the rear. here,
The condenser lens system 3 includes a front group 3a and a rear group 3b having a convex action. Further, the front group 3 of the condenser lens system 3
A rotary color separation filter 4 of a frame sequential type and an aperture mechanism 5 as a transmitted light amount adjusting means are disposed between the lens group a and the rear group 3b.

On the other hand, when a rigid endoscope, a fiberscope and a mosaic type electronic scope are used, FIG.
As shown in (b), an infrared absorption filter 2b is further inserted between the infrared reflection type interference filter 2a and the condenser lens system 3 in addition to the configuration shown in FIG. And a rotary color separation filter 4 of a frame sequential type disposed between the front group 3a and the rear group 3b. In the apparatus of the present embodiment, a driving device such as a motor (not shown) is provided for driving the infrared absorption filter 2b and the rotary color separation filter 4 of a frame sequential type.

As described above, in the apparatus of this embodiment, the rotary color separation filter 4 of the frame sequential type and the infrared absorption filter 2b are configured to be detachable from the optical path depending on the type of the scope used. Accordingly, the fiber end face of the light guide 6 does not burn when using a rigid endoscope, a fiberscope, and a mosaic type electronic scope.
Further, the brightness as illumination light can be improved even when a plane-sequential electronic scope is used.

Further, in this embodiment, the exchanged filter may be configured as shown in FIG. That is, when a plane-sequential type electronic scope is used, FIG.
As shown in FIG. 1, an infrared reflection type interference filter 2a is arranged in the same manner as in the apparatus shown in FIG. 1A, but when a rigid scope, a fiberscope, and a mosaic type electronic scope are used, FIG. The configuration is as shown in FIG. That is, instead of the interference filter 2a and the infrared absorption filter 2b shown in FIG. 1B, a filter 2d in which a multilayer film c for reflecting interference type infrared light is deposited on the light source side surface of the infrared absorption filter 2b is used. Is done. In the case of such a configuration, FIG.
The same effects as those of the device shown in FIGS. 1A and 1B can be obtained, but the space for disposing the filter is smaller than that of the device shown in FIGS. 1A and 1B. Therefore, downsizing of the light source device is promoted.

FIG. 3 is a curve diagram showing the transmittance characteristic of the infrared reflection type interference filter 2a used in the apparatus of the present embodiment. This infrared reflection type interference filter 2
In the case of using a rigid endoscope, a fiberscope and a color mosaic type electronic scope, a is used for the purpose of preventing breakage of the infrared absorption filter 2b such as cracks due to heat. When a plane-sequential electronic scope is used, the infrared absorption filter 2b
Are not arranged in the optical path, the infrared reflection type interference filter 2a has a role of preventing burning of the fiber end face of the light guide 6, and also has a role of preventing image deterioration. Therefore, the infrared reflection type interference filter 2a needs to have a wavelength range of light that can be removed as described later.

On the short wavelength side of the wavelength range of the light to be removed by the infrared reflection type interference filter 2a, it is necessary not to remove light in the visible region transmitted by the plane-sequential rotary color separation filter 4. On the other hand, solid-state imaging devices used in electronic scopes and the like have a sensitivity that extends to the infrared region. The image of the electronic scope is deteriorated. For this reason, the long wavelength side of the wavelength range of the light removed by the infrared reflection type interference filter 2a is required at least up to the infrared region where the solid-state imaging device has sensitivity.

FIGS. 8A to 8C show light wavelengths and spectral transmittances of R, G, and B transmission filters of a plane-sequential rotary color separation filter used in the apparatus of this embodiment. FIG. In the wavelength range of light transmitted by the R (red) transmission filter of the plane-sequential rotary color separation filter 4, the wavelength of light having a transmittance of 5% or less on the long wavelength side is up to about 680 nm. The long wavelength side of the wavelength range of light to which the solid-state imaging device has sensitivity is up to about 1100 nm. For this reason, when using a rigid endoscope, a fiberscope, and a color mosaic type electronic scope, the thermal load of the infrared absorption filter 2b due to infrared rays is reduced, and when a plane sequential electronic scope is used. In order to prevent image deterioration due to infrared rays without reducing R light, the wavelength range in which the transmittance of infrared rays by the infrared reflection type interference filter 2a is 5% or less is about 750 to 1100 nm or more. Is preferred. However, if the cut wavelength of light on the long wavelength side of the R light transmission filter of the field sequential type electronic scope is increased, the cut wavelength range of the short wavelength light of 800 nm is sufficient. In addition, if the light source 1 is, for example, a xenon lamp, if it can block light having a wavelength in the range of at least 800 to 1000 nm, it can sufficiently withstand practical use, even in view of its spectral characteristics.

By setting the cut wavelength range of the light incident on the infrared reflection type interference filter 2a as described above, when using a rigid endoscope, a fiberscope, and a color mosaic type electronic scope, the infrared absorption filter is used. When no trouble such as breakage of 2b occurs, and when a plane-sequential type electronic scope is used, the R light is not reduced and the image is not deteriorated by infrared rays.

That is, in this embodiment, a light source that emits white light containing components in the visible and infrared regions, a color separation filter of at least a plane sequential type, and light in the infrared region of the wavelength region of the white light. An endoscope light source device including an infrared cut filter that blocks light, when the color separation filter is disposed on an optical path from the light source to a light guide, a filter group disposed in the optical path. Is configured to transmit light having a wavelength whose total spectral transmittance is 1100 nm or more. or,
When the color separation filter is not arranged, the total spectral transmittance of the filter group arranged in the optical path is set so as to sufficiently remove light having a wavelength of 1100 nm or more. And a part or all of these filter groups are constituted so that exchange is possible. The apparatus of this embodiment solves the problems of the prior art by being configured as described above, and prevents the end face of the light guide fiber from burning when using a rigid endoscope, a fiberscope, and a color mosaic type electronic scope. In addition, the brightness as the illumination light does not become insufficient even when the plane-sequential type electronic scope is used.

In the apparatus according to the present embodiment, it is best to arrange the filter so that the incident angle of light is generally 0 ° in the case of an interference filter. The performance of the filter deteriorates as the angle of incidence of the light incident on the filter increases. For this reason, it is preferable that the infrared reflection type interference filter 2 a be disposed in a parallel light beam between the light source 1 and the condenser lens system 3. Further, in order for the surface-sequential rotary color separation filter 4 to exhibit its performance sufficiently, it is desirable that such a filter be disposed between the light source 1 which is a parallel light flux and the condenser lens system 3. In this case, since the light beam diameter is large, the rotary color separation filter 4 of the field sequential type needs to be large. As described above, when the size of the field-sequential rotary color separation filter 4 is increased, the filter is required to have considerable strength, and a large and powerful motor for driving the filter is required. Will lead to higher costs,
The weight of the device itself is considerably large.

On the other hand, if the plane-sequential rotary color separation filter 4 is disposed between the condenser lens system 3 and the light guide 6, the filter need only be a small one.
The drive motor for this filter can also be applied with a small torque. However, in this case, the light transmittance of the rotary color separation filter 4 of the frame sequential type is deteriorated, and the color reproducibility is deteriorated. It does not have practical utility.

However, if the incident angle of the light incident on the plane-sequential rotary color separation filter 4 is not more than 20 °, the deterioration of the light transmittance characteristic is not so large, and Color display is possible. FIG.
(A) to (e) show a G light transmission filter having a property of transmitting only light belonging to the wavelength range of G (green) light and reflecting light belonging to the other wavelength ranges. FIG. 7 is a diagram illustrating a change in light transmittance characteristics when the magnitude of an incident angle of light incident on an interference film surface is changed. At this time, although the central wavelength region of the G light set in the G light transmission filter is 510 to 560 nm, FIG.
According to (b), when the magnitude of the incident angle of light exceeds 20 °, the light transmittance characteristic with respect to the central wavelength region is significantly deteriorated.

Therefore, in the apparatus of the present embodiment, the condenser lens system 3 has a two-group structure of a front group 3a and a rear group 3b, and a plane-sequential rotary color separation filter 4 is arranged between them. The front group 3a includes a rotary color separation filter 4 of a frame sequential type.
The parallel light flux can be condensed to such an extent that the light transmittance does not deteriorate. in this way,
By arranging the plane-sequential rotary color separation filter 4 between the front group 3a and the rear group 3b, such a filter can be made small and can maintain sufficient light transmittance characteristics.

When a rigid endoscope, a fiberscope and a color mosaic type electronic scope are used, an infrared absorption filter 2b is inserted into the optical path of the apparatus.
The infrared absorption filter 2b needs to be disposed between the infrared reflection type interference filter 2a and the condenser lens system 3. This is because if the infrared absorption filter 2b is arranged at the rear light collection position of the condenser lens system 3 or in front of the infrared reflection type interference filter 2a, this filter may be damaged.

When a rigid endoscope, a fiberscope, and a color mosaic type electronic scope are used, the white light emitted from the light source 1 of the apparatus of this embodiment is not separated into R, G, and B, and is simultaneously collected. Since the light is condensed on the fiber end face of the light guide 6 by the lens system 3, the infrared light is almost completely removed from the white light emitted from the light source 1, unlike the case where a plane-sequential electronic scope is used. Need to be done. Therefore, the infrared reflection type interference filter 2a
And the infrared absorption filter 2b must be used in combination. FIG. 4 is a curve diagram showing light transmittance characteristics of the infrared absorption filter 2b. From this figure, it can be seen that the infrared absorption filter 2b almost completely blocks the light in the infrared region. Therefore, there is no possibility that the fiber end surface of the light guide 6 may be burned.

Second Embodiment FIG. 6 shows the configuration of a light source device for an endoscope according to the present embodiment. FIG. 6A is a device configuration diagram in the case where a plane-sequential type electronic scope is used. FIG. 2B is an apparatus configuration diagram when a rigid endoscope, a fiberscope, and a mosaic type electronic scope are used.

The apparatus of this embodiment is configured as shown in FIG. 6A when using a plane-sequential electronic scope. That is, the light emitted from the light source 1 is collected by the condenser lens system 3.
An interference filter 7a of an infrared transmission type is arranged so that the light can be reflected toward. The infrared transmission type interference filter 7a is arranged such that the normal line of the filter forms an angle of 45 ° with respect to the incident light, and transmits only light in the infrared region and transmits light in the visible region. It has the function of reflecting. Condensing lens systems 3, other than the light source 1 and the infrared transmission type interference filter 7a
The same as the device shown in the first embodiment (see FIG. 1A) is used for the plane-sequential rotary color separation filter 4, the diaphragm mechanism 5 as the transmitted light amount adjusting means, and the light guide 6; They are arranged similarly.

When a rigid endoscope, a fiberscope and a color mosaic type electronic scope are used, FIG.
As shown in (b), the infrared absorption filter 2b is inserted in the optical path between the infrared transmission type interference filter 7a and the condenser lens system 3 of the device shown in FIG. The rotary color separation filter 4 of the frame sequential type, which is disposed between the front group 3a and the rear group 3b, is removed. In the apparatus of the present embodiment, similarly to the apparatus of the first embodiment, a driving device such as a motor (not shown) is provided to drive the infrared absorption filter 2b and the plane-sequential rotary color separation filter 4. ing.

Since the light source device for an endoscope according to the present embodiment is constructed as described above, similar to the device shown in the first embodiment, when a plane-sequential type electronic scope is used, Brightness as illumination light can be improved.
On the other hand, even when a rigid endoscope, a fiberscope, and a color mosaic type electronic scope are used, stable illumination light can be provided without breakage of the infrared absorption filter or burning of the fiber end face of the light guide.
Further, in the device of the first embodiment, since the infrared reflection type interference filter is used, the light in the infrared region is reflected again toward the light source, and there is a possibility that the light source itself may be damaged. However, in the apparatus of the present embodiment, since the infrared transmission type interference filter is used, the light in the infrared region is not reflected again toward the light source, and there is no possibility that the light source may be damaged. , Which is superior to the device of the first embodiment.

Third Embodiment FIG. 7 shows a configuration of a light source device for an endoscope according to the present embodiment. FIG. 7A is a device configuration diagram in the case where a plane-sequential electronic scope is used. FIG. 2B is an apparatus configuration diagram when a rigid endoscope, a fiberscope, and a mosaic type electronic scope are used.

FIGS. 7A and 7B show the apparatus of this embodiment.
It has a configuration as shown in FIG. That is, first, an infrared reflection type interference filter 2a and an infrared absorption filter 2 are provided in an optical path connecting the light source 1 and the condenser lens system 3 having a convex action.
b are arranged. A total reflection prism 8a is disposed between the infrared reflection interference filter 2a and the infrared absorption filter 2b, and a total reflection prism 8d is disposed between the infrared absorption filter 2b and the condenser lens system 3. ing. These total reflection prisms 8a and 8d change the direction of the incident light by 90 ° and reflect the light, and both of them are moved up and down from the position shown in FIG. 7A to the position shown in FIG. You can move vertically to the direction. Above the total reflection prisms 8a and 8d, total reflection prisms 8b and 8c similar to these are disposed, respectively, so that the direction of incident light can be changed by 90 ° and reflected. Further, the total reflection prism 8a and the total reflection prism 8
d, a plane-sequential rotary color separation filter 4 is arranged, and a light guide 6 is arranged behind the condenser lens system 3. An aperture mechanism 5 as a transmitted light amount adjusting means is disposed between the two.

Therefore, in the apparatus of this embodiment, when a plane-sequential type electronic scope is used, the light emitted from the light source 1 is reflected by an infrared reflection type interference filter as shown in FIG. By passing through 2a, most of the components in the infrared region are removed. Further, the light follows an optical path such that the light is incident on the condenser lens system 3 through the plane-sequential rotary color separation filter 4 by the total reflection prisms 8a, 8b, 8c and 8d. On the other hand, when a rigid endoscope, a fiberscope, and a mosaic type electronic scope are used, all the prisms 8a and 8d slide out of the optical path and are emitted from the light source 1 as shown in FIG. Most of the infrared light is removed by passing through the infrared reflection type interference filter 2a. Further, the light is incident on the condenser lens system 3 after components in the infrared region are completely removed by passing through the infrared absorption filter 2b.

Since the light source device for an endoscope according to the present embodiment is constructed as described above, similar to the devices shown in the first and second embodiments, the light source device for a field sequential type is used. Can improve the brightness as illumination light. On the other hand, when a rigid endoscope, a fiberscope, and a mosaic type electronic scope are used, similarly to the apparatus shown in the first and second embodiments, the infrared absorption filter may be damaged or the fiber end face of the light guide may be scorched. There is no problem or damage to the infrared absorption filter. Furthermore,
In the apparatus shown in the first and second embodiments, when switching between the use of the frame sequential electronic scope and the use of the rigid endoscope, the fiberscope and the mosaic type electronic scope, the infrared absorption filter 2b and the frame sequential are used. It is necessary to move the rotary type color separation filter 4 of the type, so that a large motor is required for driving these filters, which leads to high costs and increases the weight of the entire apparatus. I will. However, in the apparatus of this embodiment, since only the two small total reflection prisms described above are moved, only a small driving motor is required, and the cost and the size of the apparatus can be reduced. Can be.

Fourth Embodiment FIGS. 9A and 9B show the configuration of a light source device for an endoscope according to the present embodiment, wherein FIG. 9A is a device configuration diagram when a plane-sequential electronic scope is used, and FIG. It is a device block diagram at the time of using a rigid endoscope, a fiberscope, and a color mosaic type electronic scope. In the apparatus according to the present embodiment, the light emitted from the light source used when using the rigid endoscope, the fiberscope, and the color mosaic type electronic scope is considerably strong, and the light in the infrared region is almost completely removed to only the light in the visible region. Also, in order to cope with the case where the fiber end face of the light guide burns, a light-reducing means such as a light-reducing mesh is inserted and arranged in the optical path.

When a plane-sequential electronic scope is used in the apparatus of this embodiment, first, as shown in FIG. 9A, a light source 1 and an infrared reflection type interference filter 2a are used.
And a condensing lens system 11
And a light guide 6 are arranged. Furthermore,
A turret plate 12 is disposed between the lamp house 10 and the condenser lens system 11.
Is empty so that its optical path does not block the light beam. The condenser lens system 11 includes convex lenses 11a to 11d.
Of four. Then, the convex lens 11a
An aperture mechanism 5 as a transmitted light adjusting means is disposed between the convex lens 11b and the convex lens 11b, and a plane sequential rotary color separation filter 4 is disposed between the convex lens 11b and the convex lens 11c.

On the other hand, when a rigid endoscope, a fiberscope and a color mosaic type electronic scope are used, the turret plate 12 in the configuration shown in FIG. 9A is rotated as shown in FIG. By doing so, the light-reducing mesh 13 and the infrared absorption filter 2b are simultaneously arranged in the optical path, and in synchronization with this, the plane-sequential rotary color separation filter 4 is removed from the optical path. The light-attenuating mesh 13 is made of metal, and the light-attenuating mesh 13 and the infrared absorption filter 2b are integrally mounted on the turret plate 12, and the arrangement of the light-attenuation mesh 13 and the infrared absorption filter 2b is performed from the light source 1 side. It is in order.

Since the apparatus of this embodiment is configured as described above, similarly to the apparatus shown in the first, second and third embodiments, when a plane-sequential type electronic scope is used, The brightness as the illumination light can be improved.On the other hand, even when using a rigid endoscope, a fiberscope or a color mosaic type electronic scope, the infrared absorption filter is not damaged and the fiber end face of the light guide is not burned. Stable illumination light can be supplied. Further, since the light-attenuating mesh 13 used in the device of the present embodiment is disposed between the light source 1 and the infrared absorption filter 2b,
In addition to the effect of protecting the fiber end face of the light guide 6,
Since it also has the effect of reducing the amount of light absorbed by the infrared absorption filter 2b, the thermal load on the infrared absorption filter 2b can be reduced, and thermal deformation or cracking can be prevented.

However, the light reducing mesh 1
If 3 is arranged in the optical path, the light-attenuating mesh 13 itself is also heated to a considerably high temperature and generates heat by itself. In general, it is known that a heating element emits infrared rays.
Therefore, the infrared rays emitted from the light-attenuating mesh 13 are also removed. The darkening mesh 13 is connected to the infrared absorption filter 2b.
In the case of a configuration arranged closer to the condenser lens system 11 than
Not only can the thermal load on the infrared absorption filter 2b not be reduced, but also the infrared light generated as a result of the heating of the light reducing mesh 13 heats the light guide 6, and the light reducing mesh 13 is placed in the optical path. Since the effect of protecting the light guide 6 by being inserted is impaired,
Not preferred.

Further, when the brightness as illumination light is sufficiently ensured when using the plane-sequential type electronic scope,
The light source device for an endoscope of the present embodiment may be configured as shown in FIG. That is, when a plane-sequential type electronic scope is used, as shown in FIG.
A light source 1, a darkening mesh 13, and an interference filter 2 a of an infrared reflection type are disposed in a turret plate 12 disposed between a lamp house 10 and a condenser lens system 11.
Is made empty so as not to block the light beam. As in the device shown in FIG. 9A, the light-reducing mesh 13 is made of metal, and the light-reducing mesh 13 and the infrared reflection type interference filter 2a are arranged in this order from the light source 1 side. The arrangement of the condenser lens system 11, the aperture mechanism 5, the plane-sequential rotary color separation filter 4, and the light guide 6 is the same as that of the apparatus shown in FIG. 9A.

On the other hand, when a rigid endoscope, a fiberscope and a color mosaic type electronic scope are used, as shown in FIG. 10B, the turret plate 12 in the configuration shown in FIG. By doing so, the infrared absorption filter 2b is inserted and arranged in the optical path, and in synchronization with this, the plane sequential rotary color separation filter 4 is removed from the optical path.

In such a configuration, FIG.
The same effect as the device shown in (a) and (b) is obtained,
The fiber end face of the light guide 6 can be protected and the thermal load on the infrared absorption filter 2b can be reduced. Further, in the case where the light source 1 emits strong light, if an interference filter is arranged near the light source 1, the interference film of the interference filter is often deteriorated by heat to change the interference characteristics. Since the light reducing mesh 13 is disposed closer to the light source 1 than the infrared reflection type interference filter 2a,
The amount of light incident on the infrared reflection type interference filter 2a is reduced, which also has the effect of protecting the interference film of the infrared reflection type interference filter 2a.

Each filter used in the apparatus of this embodiment has the same characteristics as those used in the apparatus of the first, second and third embodiments.
Accordingly, the spectral transmittance graph of each filter also shows that the infrared reflection type interference filter 2a is shown in FIG. 3, the infrared absorption filter 2b is shown in FIG. 4, and the plane sequential rotary color separation filter 4 is shown in FIG. It is the same as each shown.

In the apparatus of this embodiment, the infrared reflection type interference filter 2a and the infrared absorption filter 2b are used.
Are used only one each, but a plurality of each may be used. Further, although the metal light reducing mesh 13 is used as the light reducing means, the same effect can be obtained by using another light reducing means such as an ND filter instead of the light reducing mesh 13. Further, as long as the arrangement positions of the infrared cut filters and the dimming means are the same as those shown in the present embodiment, a similar effect can be obtained by using a member other than the lamp house 10 and the turret plate 12. be able to.

Further, the present invention has the following features, in addition to the features described in the claims , as is clear from the description of the above embodiments.

(1) The light source device for an endoscope according to claim 3 , wherein a part or all of the filter group is replaceable.

(2) The light source device for an endoscope according to claim 2 , wherein the group of interference filters is arranged in a parallel light beam between the light source and the condenser lens system.

(3) The light source device for an endoscope according to claim 2 , wherein the infrared absorption filter is configured to be detachable from the optical path.

(4) Light intensity in the interference filter group
The range of the cut wavelength region where the transmittance is 5% or less is small.
At least 800-1000 nm
The light source device for an endoscope according to claim 5 .

(5) The light source device for an endoscope according to claim 2 , wherein the infrared absorption filter group is disposed in an optical path between the interference filter group and the condenser lens system. .

(6) The plane-sequential rotary color separation filter is disposed in an optical path between a front group and a rear group of a condenser lens system composed of two groups. Item 2
The light source device for an endoscope according to claim 1.

(7) The light source device for an endoscope according to claim 2 , wherein the interference filter group is an infrared transmission type filter.

[0058]

[0059]

[0060]

[0061]

[0062]

( 8 ) In the case where the plane-sequential color separation filter is arranged in the optical path, the wavelength cut by the filter group in the white light emitted from the light source is shorter than the shorter wavelength side. The light source device for an endoscope according to claim 2 or 3 , wherein the long wavelength side is determined by the interference filter, which is determined by the color separation filter.

[0064]

[0065]

As described above, according to the present invention, problems such as burn-in of the end face of the light guide fiber and breakage of the infrared absorption filter do not occur, and the illumination can be performed even when using the field sequential type electronic scope. For endoscopes capable of supplying optimal illumination light when using any of a rigid endoscope, a fiberscope, a color mosaic type electronic scope, and a plane-sequential type electronic scope that does not lack light brightness. A light source device can be provided.

[Brief description of the drawings]

FIG. 1 shows a configuration of a light source device for an endoscope according to a first embodiment, in which (a) a device configuration diagram when a plane-sequential type electronic scope is used, and (b) a rigid scope, a fiberscope, and a color. It is a device block diagram at the time of using a mosaic type electronic scope.

FIG. 2 shows the configuration of another example of the endoscope light source device according to the first embodiment, in which (a) is a device configuration diagram when using a plane-sequential type electronic scope, and (b) is a rigid endoscope. FIG. 2 is an apparatus configuration diagram when a fiber scope and a color mosaic type electronic scope are used.

FIG. 3 is a curve diagram showing transmittance characteristics of an infrared reflection type interference filter used in the apparatus shown in FIG. 1;

FIG. 4 is a diagram showing transmittance characteristics of an infrared absorption filter used in the device shown in FIG.

5 (a) to 5 (e) show a G light transmission filter having a characteristic of transmitting only light belonging to the wavelength range of G (green) light and reflecting light belonging to other wavelength ranges. FIG. 7 is a diagram showing a change in light transmittance characteristics when the magnitude of an incident angle of light incident on the interference film surface of the filter is changed.

FIG. 6 shows the configuration of a light source device for an endoscope according to a second embodiment, in which (a) is a device configuration diagram when a plane-sequential type electronic scope is used, and (b) is a rigid endoscope, a fiberscope, and a color. It is a device block diagram at the time of using a mosaic type electronic scope.

FIGS. 7A and 7B show the configuration of a light source device for an endoscope according to a third embodiment, in which FIG. 7A is a device configuration diagram when a plane-sequential type electronic scope is used, and FIG. It is a device block diagram at the time of using a mosaic type electronic scope.

8A and 8B are diagrams showing transmittance characteristics of a plane-sequential rotary color separation filter, wherein FIG. 8A shows an R light transmission filter,
(B) is a diagram of a G light transmission filter, and (c) is a diagram of a B light transmission filter.

9A and 9B show the configuration of a light source device for an endoscope according to a fourth embodiment, wherein FIG. 9A is a device configuration diagram when a plane-sequential type electronic scope is used, and FIG. It is a device block diagram at the time of using a mosaic type electronic scope.

10 shows another example of the configuration of the light source device for an endoscope shown in FIG. 9, wherein (a) is a device configuration diagram when a plane-sequential type electronic scope is used, and (b) is a rigid endoscope and a fiber scope. FIG. 2 is a configuration diagram of a device when a color mosaic type electronic scope is used.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Light source 2a Infrared reflection type interference filter 2b Infrared absorption filter 2d Infrared absorption filter on which multilayer film which reflects infrared rays was deposited 3,11 Condensing lens system 3a Front group 3b Rear group 4 Surface-sequential rotary color separation filter 5 Aperture mechanism 6 Light guide 7a Infrared transmission type interference filter 8a, 8b, 8c, 8d Total reflection prism 10 Lamp house 11a, 11b, 11c, 11d Convex lens 12 Turret plate 13 Darkening mesh

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Shinya Matsumoto 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (56) References JP-A-5-232387 (JP, A) JP-A Heisei 2-106713 (JP, A) JP-A-57-5020 (JP, A) JP-A-2-291516 (JP, A) JP-A-3-51411 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 23/26 A61B 1/06

Claims (5)

(57) [Claims] 1. A light source that emits white light containing components in the visible and infrared regions, a color separation filter of at least a plane-sequential type, and an infrared ray cutoff device that blocks light in the infrared region of the wavelength region of the white light. in the endoscope light source device provided with a filter, and a case where the color separation filter in the optical path reaching the light guide from the light source is arranged, in the case where the color separation filter in the optical path is not disposed In the red
A light source device for an endoscope, wherein a configuration of an external line cut filter is different . 2. An optical path from said light source to a light guide.
When the color separation filter is arranged inside,
The infrared cut filter has an interference film on a transparent substrate.
Consisting of a group of interference filters,
If no color separation filter is installed, the red
The outer line cut filter is at least
Infrared absorption filter that absorbs light having a wavelength in the infrared region
2. The method according to claim 1, wherein the first and second groups are arranged in a group.
The light source device for an endoscope according to claim 1. 3. When the color separation filter is arranged in an optical path from the light source to a light guide,
The infrared cut filter disposed in the optical path is a group of filters configured to transmit light having a wavelength of 1100 nm or more, while the color separation filter is disposed in the optical path. If not, the infrared cut filter disposed in the optical path has a wavelength of 1100 nm out of light in the infrared region.
The light source device for an endoscope according to claim 1, wherein the light source device for an endoscope is a group of filters configured to sufficiently remove light having a wavelength of 1100 nm or more in addition to light having the following wavelengths . 4. A light source for emitting white light containing components in the visible and infrared regions, at least a surface-sequential type color separation filter, and blocking light in the infrared region of the light in the wavelength region of the white light. An endoscope light source device including an infrared cut filter group, wherein the color separation filter is disposed in an optical path from the light source to a light guide, and the color separation filter is not disposed in the optical path. In some cases, by configuring a part or all of the infrared cut filter group arranged in the optical path so as to be exchangeable , in the two cases
2. The light source device for an endoscope according to claim 1, wherein a configuration of the infrared cut filter is different . 5. The interference filter group includes an infrared reflection type filter, and a cut wavelength region in which light transmittance in the interference filter group is 5% or less is at least a short wavelength side of the plane sequential rotary color. The wavelength longer than the wavelength at which the light transmittance of the separation filter is 5% or less, and the longer wavelength side of the cut wavelength is longer than the infrared wavelength range where the image sensor has sensitivity. Claim 2
The light source device for an endoscope according to claim 1.