JPH0249302A - Light source device - Google Patents

Abstract

PURPOSE:To improve the wavelength characteristic of each transmitting light by using a rotary color filter which has color transmitting filter parts and a non-filter part, and a rotary color filter which has infrared cut filter parts and an infrared ray transmitting filter part. CONSTITUTION:The non-filter part 21d of a rotary color filter 21 is opposed to the infrared ray transmitting filter part 22b of a rotary color filter 22, while the red, the green, and the blue filters 21a to 21c of the rotary color filter 21 are in the condition opposite to the filters 22a of the rotary color filter 22, and a motor 23 is operated in such a condition. As a result, when the filters 21a, 21b, and 21c are positioned to the light passage from a light source 10 respectively, the light having only the wavelength component of the red, green, or blue is transmitted. Consequently, the lighting with three primary colors can be carried out in order. At the same time, the infrared rays can be cut securely. Furthermore, since the filter part 22b of the filter 22 is positioned at the light passage when the non-filter part 21d of the filter 21 is positioned at the light passage from the light source 10, the light having only the wavelength component of the infrared rays can be transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention is applicable to electronic endoscopes, etc., in which illumination light is irradiated toward an observation target, and the optical image is transmitted through electrical communication using imaging means. The present invention relates to a light source device for irradiating illumination light toward an observation target in an image forming system that converts the signal into a signal, processes the signal, and displays the signal on a display device.

■Prior art 1 As for endoscopes used for medical purposes, in recent years, electronic endoscopes having a solid-state imaging device such as a COD at the tip of the insertion portion have come into use. Here, since it is necessary to make the insertion section of the endoscope as thin as possible, only one solid-state image sensor can be provided at the tip of the insertion section, and this one element In order to obtain clear images, the information for each color image of red, blue, and green is extracted in a frame-sequential manner. Therefore, in the light source device of an electronic endoscope equipped with this field-sequential solid-state image sensor, a rotating color filter that transmits the red (R), green (G), and blue (B) wavelength regions is used. By intervening this rotating color filter in the optical path from the light source and rotating it,
A device that obtains image information of the three primary colors of R, G, and B by sequentially irradiating light in each of the wavelength ranges described above in time series has been used in the past.

[Problem to be Solved by the Invention 1] By the way, when performing examinations, diagnosis, etc. using an endoscope, for example, it is necessary to obtain information such as the position and shape of a lesion, and to determine the outline shape of this lesion. For this purpose, it is necessary to generate image information based on infrared light.

It is also useful when connecting an endoscope with a built-in solid-state image sensor equipped with a so-called mosaic filter in which R, G, and B color filters are arranged in a checkerboard pattern, or when displaying a monochrome display device to observe the target area. When displaying an image, it may be necessary to illuminate with white light. Furthermore, in order to confirm the position of the tip of the insertion tube in the patient's body, it is necessary to increase the amount of illumination light emitted from the tip of the insertion tube as much as possible. be.

However, in the light source device according to the prior art described above,
The rotating color filters interposed in the optical path from the light source are the three primary color filters of R, G, and B, and there is no filter that is integrated with a filter that transmits infrared light. The illumination light in the wavelength range is the red, green,
Since it is not designed to sequentially illuminate the three primary colors of blue in a continuous manner, it is difficult to obtain image information based on infrared light. In addition, in order to perform illumination with white light, this rotating color filter must be removed from the optical path of the illumination light, but for this purpose, a mechanism for inserting and removing the rotating color filter into the optical path is attached. However, there are problems in that the structure of the light source device becomes complicated and large.

The present invention has been made in view of the above points, and its purpose is to convert light in the infrared wavelength region into R, G,
It is an object of the present invention to provide a light source device that can irradiate an observation target area with illumination of wavelengths of each color B, and can also easily illuminate with white light.

[Means for Solving the Problems 1] In order to achieve the above-mentioned object, the present invention provides red and green lights respectively in the optical path of the illumination light from the illumination light source.

A rotary color filter having each color transmission filter section that transmits each blue wavelength region and each division section of a non-filter section, and an infrared light cut filter section that reflects an infrared wavelength region.
A rotary color filter having one division and one division of an infrared light transmitting filter portion that transmits an infrared wavelength region is provided facing the rotary color filter, and both rotary color filters are rotated simultaneously by a rotation driving means. In addition, one rotating color filter can be rotated relative to the other, and when both rotating color filters rotate, red, blue, green, and infrared wavelength region light is sequentially generated, and when rotation is stopped, red, blue, green, and infrared wavelength region light is generated sequentially. Its feature is that it is configured to generate illumination light that cuts out external light.

[Function 1] With the configuration as described above, the non-filter part of one of the rotary color filters is overlapped with the infrared light transmitting filter part, and both of the rotary color filters are driven by the rotation driving means. By rotating them simultaneously, red, blue, green, and infrared spring light can be continuously and periodically generated in a time-series manner. In addition, one of the rotating color filters is stopped from rotating so that its non-filter part faces the optical path, and in this state, the other rotating color filter is rotated by a predetermined angle to open its infrared light cut filter part. If it is moved to a position facing this optical path, the light from which infrared light has been removed will pass through this rotating color filter, and a large amount of white light can be illuminated.

[Embodiment 1] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

First, FIG. 1 shows the basic configuration of a light source device according to the present invention. In the figure, l represents a light source device, and 2 represents an endoscope. Inside the light source device l, there is built-in a light source 10 consisting of a lamp or the like that emits light at wavelengths in both the visible and infrared regions. The illumination light from this light source 10 is transmitted through the light guide 11 to the distal end of the insertion section 2a of the endoscope 2, so that it can illuminate the observation target.

Next, a filter device 20 is interposed between the light source IO and the light guide 11. This filter device 20 includes a rotating color filter 21.2 formed in the shape of two discs.
2, and each of these rotating color filters 21 and 22 is rotatably driven by a motor 23. Here, the rotating color filters 21 and 22 are shown in FIG.
The configuration is as shown in a) and (b).

First, as is clear from FIG. 2(a), the filter 21 consists of four fan-shaped filters 21a to 21d with a central angle of 80°.
The first partition part 21a is a red filter part equipped with a filter that transmits light in the red (R) wavelength range, and the second partition part 21b is a red filter part equipped with a filter that transmits light in the red (R) wavelength range. The third section 21c is a blue filter section equipped with a filter that transmits light in the blue (B) wavelength region, and the fourth section 21d is equipped with a filter that transmits light in the blue (B) wavelength range. This is a non-filter part that has no function, and is fitted with glass or the like, or is held in a space. Note that, as will be described later, if infrared light is used for illumination, and far infrared light is used, glass or the like should not be attached.

Further, the filter 22 includes an infrared light cut filter section 22a that cuts infrared light (IR) and an infrared light filter section that transmits the wavelength region of infrared light, as is clear from the second [M(b)]. 22b is formed, and when this filter 22 is divided into four fan-shaped sections with an angle of 90'', the infrared light cut filter section 22a occupies three divisions, that is, a % portion, and the infrared light The filter portion 22b corresponds to the remaining one section, that is, the portion A.

When rotating the rotating color filters 21 and 22 configured in this way by the motor 23, the filters 21 and 22 are rotated by the motor 23.
The non-filter portion 21d faces the infrared light transmitting filter portion 22b of the filter 22. Further, when one rotation is stopped, the non-filter portion 21d of the filter 21 faces the infrared light cut filter portion 22a, and this portion is maintained in the optical path from the light source 10.

Therefore, both the filters 2t, 22 are connected to the motor 23 via a mechanism that allows them to be rotated simultaneously and to rotate one filter relative to the other filter by a predetermined angle. . In this mechanism, the rotating color filter 22 on one side is directly connected to the rotating shaft 24 of the motor 23, and the rotating color filter 21 on the other side is connected directly to the rotating shaft 24 of the motor 23.
This can be achieved by employing a configuration in which the rotation shaft 24 is connected to the rotating shaft 24 so as to be able to come into contact with and separate from it via a contact and separation mechanism.

That is, the rotating color filter 21 is attached to a driven cylinder 25, and a spring 2G is applied to the driven cylinder 25 to push it in the direction indicated by arrow A in FIG. In this state, the driven cylinder 25 is engaged with the rotating shaft 24 and rotated together with it, and is also slid in the direction of arrow B in the figure by an actuator (not shown) such as a solenoid. Sometimes, the driven cylinder 25
If the motor 23 is rotated in this state, the driven cylinder 25 and the rotating color filter 21 attached to it will not rotate even if the rotating color filter 22 is rotated. will be retained in the state.

Here, in order to control the rotation of the rotating color filters 21 and 22, the motor 23 is connected to a motor drive control circuit 27, and its drive is controlled based on a signal from the motor drive control circuit 27. It has become. Furthermore, when the rotating color filters 21 and 22 are stopped from being rotated at the same time, the non-filter portion 21d of the rotating color filter 21 must first be placed in a position facing the optical path from the light @10. For this purpose, the rotating color filter 22 is provided with a position index 28, and in order to detect the position of this position index 28, a filter rotation position detection sensor 29 is arranged so as to face the rotation locus. has been done.

As a result, when the motor drive control circuit 27 outputs a stop signal to the motor 23, the rotating color filters 21 and 22 stop when the position index 28 of the rotating color filter 22 is detected by the detection sensor 29. It is designed to be pushed up.

In this state, based on the signal from the motor drive control circuit 27, the driven cylinder 25 and the rotating shaft 24 are first disengaged, and then the motor 23 is activated, and only the rotating color filter 22 is disengaged. It is designed so that it can be rotated by 90''.

The light source device according to the present invention is constructed as described above, and its operation will be explained next.

First, the non-filter part of the rotating color filter 21 faces the infrared light transmitting filter part 22b of the rotating color filter 22, and each of the red, green, and blue filter parts 2Ja to 2Lc faces the infrared light cut filter part 22a. The motor 23 is in a state where the motor 23 is
Activate.

As a result, as shown in FIG.
1a is located on the optical path from the light source 10, (c)
As shown in FIG. 2, among the four illumination lights, only the light having the red wavelength component is transmitted and sent into the light guide 12. Next, when the green filter section 21b is located on the optical path, light having only the green wavelength component is transmitted, as shown in (b), and when the blue filter section 21c is located on the optical path, (a ), light having only blue wavelength components is transmitted. This makes it possible to perform sequential illumination using the three primary colors. Furthermore, each of these filter sections 21 . a
Since the infrared light cut filter part 22a of the filter 22 faces 21c, even if light containing a large amount of infrared light is irradiated, the infrared light can be reliably cut, and the transmitted light can be The wavelength characteristics become extremely good. In addition to this, the non-filter portion 21d of the filter 21 or the light source 10
When the infrared light transmission filter part 22b of the filter 22 is located in this optical path, as shown in FIG. This means that you will be able to do so.

Therefore, the light guide 11 includes red (R), M (G),
Blue (B) and infrared (IR) illumination light can be sequentially and periodically irradiated at regular time intervals.

Then, the rotating color filter 21 in the filter device 20
．． To stop the rotation of the motor 22, the motor drive control circuit 27 outputs an operation stop signal F to the motor 23. Based on this, the detection sensor 29 is activated and the filter 2
When the position index 28 provided at 2 is detected, the filters 21, 22 are stopped. As a result, the non-filter portion 21 of the rotating color filter 21
It will stop at a position facing the optical path from the light source 10. After that, the driven cylinder 25 slides in the direction of arrow B in FIG. You will be forced to do so. In this state, the motor 23 is started again and the two color filters are rotated 906 times for one rotation, so that the infrared light cut filter part 22a of the filter 22 faces the non-filter part 21d of the filter 21. It comes.

As a result, the light guide 11 receives white light (R+
G+B) illumination can be performed. Here, since the light intensity of this illumination light is large, when the insertion section 2a of the endoscope 2 is inserted into the body, the position of the tip part can be confirmed from outside the body by the light leaking through the body skin. You will be able to do this.

Next, an example of an image forming system for forming an image of an observation target area while the observation target area is illuminated by the light source device as described above will be described with reference to FIG. 4.

In the figure, 30 is a solid-state image sensor such as a CCD.

Reference numeral 31 indicates a processor, and 32 indicates a display device. The image signal from the solid-state image sensor 30 is transmitted to the processor 31, and after being subjected to predetermined signal processing by the processor 31, the image signal is displayed on the display device 32. It has become.

That is, the image signal of the observation target area obtained by photoelectric conversion by the solid-state image sensor 30 is selectively input to either the frame sequential processing section 34 or the non-field sequential processing section 35 by the switching means 33. At this point, switching between the field sequential processing section 34 and the non-field sequential processing section 35 is automatically performed by the above-mentioned illumination method. R, G, by rotation of the rotating color filters 21 and 22.
When sequential B and IR illumination is being performed, the frame sequential processing section 34 is selected, rotation of the rotating color filters 21 and 22 is stopped, and R+G+8 illumination that does not include infrared light is performed. If so, the non-sequential processing section 35 is selected.

The R, G, B, and IR color image signals obtained by the solid-state image sensor 30 in a time-divisional manner are transmitted to the solid-state image sensor 3.
By applying a clock pulse to 0 and driving it, the image signals of each color are sequentially input to the frame sequential processing section 34, and these color image signals are input to the A/D converter 36 and these Color image signals are increasingly being digitized. This signal is then transmitted to the switching means 37.
The data of each color image is written into the frame memory. Here, the frame memory is R
, G, B, and IR color image signals, the four memory areas of 38R, 38G, :18B, and 38IR are collapsed, and the output side of each of these frame memories is converted to analog. D for Zurome
/A converter 39 is connected. And frame memories 38R, 38G, :R and G from I8B.

The B color image signals are simultaneously read out by the color composite signal generation encoder 40 and displayed on the display device 32 via the display mode selection switch. Further, each color image signal is also input to a two-screen processing circuit 42.

Next, the infrared image data from the frame memory 18IR is either directly displayed on the display device 32 via the display mode selection switch 41, or is input to the two-screen processing circuit 42 together with each color image signal mentioned above. The output from the two-screen processing circuit 42 allows the display device 32 to display two screens, a color image and an IR image, in parallel. Here, the 18th image is for displaying data regarding the heat distribution of the observation target area, and it is possible to display the position and shape of the lesion part using this image.

Furthermore, each of the above-mentioned R, G, B, and IR image signals is IR
The signal amplifier 43 is also manually powered, and the r
The IR section gate pulse is input to the R signal amplifier 43, and only the TR image signal is taken out, and an IR contour shape signal is obtained by the IR contour binarization circuit 44. By inputting this signal to the color composite signal generation encoder 40, it is possible to superimpose IR contour information such as the contour of a lesion on the color image described above. It should be noted that whether or not to perform this IR contour information matching can be selected by operating the switch 45.

On the other hand, when the non-sequential processing section 35 is selected by the switching means 33, the display mode selection switch 41 allows display on the display device 32. Therefore, this non-field sequential processing unit 35 is suitable for signal processing from other types of image sensors that can form color image signals by illuminating with white light, such as a CC-D with a built-in mosaic filter. and a processing circuit.

Furthermore, if a processing circuit suitable for forming a monochrome image is provided, this processor 34 can be equipped with a CC with a built-in mosaic filter when illuminating with white light.
It becomes possible to connect an endoscope equipped with D, and to display images of the observation target area on a monochrome screen.

[Effects of the invention 1 As explained above, according to the present invention, red.

a rotating color filter having a color transmission filter section and a non-filter section for transmitting each wavelength region of green and blue;
Using a rotating color filter having three infrared light cut filter sections and one infrared light transmission filter section that transmits an infrared light wavelength region, these can be simultaneously rotated by a rotation driving means, and Since one filter can be rotated relative to the other, when rotating both rotary color filters, not only red, blue, and green but also infrared wavelength light is mixed at a ratio of 1:1. When the rotation is stopped, it is possible to generate illumination light that cuts off infrared light, so there is no need to provide a mechanism for injecting light into the optical path of the rotating color filter. It is possible to switch between illumination and white light illumination, and when sequentially illuminating the three primary colors, a filter is used that transmits each wavelength of red, green, and blue, and it also cuts infrared light from this transmitted light. Since the transmitted light is passed through a filter, the wavelength characteristics of each transmitted light are significantly improved, and other effects are achieved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory diagram of the configuration of a light source device, FIGS. 2(a) and (b) are explanatory diagrams of the configuration of different rotating color filters, and FIG. The wavelength characteristic diagram of light, FIG. 4 is a circuit diagram of the image forming system. 1: light source device, 2: endoscope, 10: light source, 11. light guide, 20: filter device, 21.22: rotating color filter, 21a: red filter section, 21b: green filter section,
21C: Blue filter section, 21d: Non-filter section, 22a
: Infrared light cut filter section, 22b=Infrared light filter section, 23: Motor, 24: Rotating shaft, 25: Driven cylinder, 26
: Spring, 27: Motor drive control circuit, 28: Position index, 29: Detection sensor, 30: Solid-state image sensor, 31
: Processor, 32: Display device.

Claims (1)

[Claims] In the optical path of the illumination light from the illumination light source, there is a rotating color filter that has a color transmission filter section that transmits red, green, and blue wavelength regions, and a non-filter section that reflects the infrared wavelength region. A rotating color filter having three sections of an infrared light cut filter section that transmits the wavelength region of the infrared light and one section of the infrared light transmitting filter section that transmits the wavelength region of the infrared light is provided facing the rotary color filter, and both of the rotary color filters are They can be rotated simultaneously by the rotation drive means, and one rotary color filter can be rotated relative to the other, and when both rotary color filters are rotated, each of the red, blue, green, and infrared wavelength regions is emitted. A light source device characterized in that it is configured to generate illumination light sequentially and, when rotation is stopped, generate illumination light with infrared light cut.