JPH0820610B2 - Light source - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention irradiates illumination light toward an object to be observed, such as an electronic endoscope, and outputs its optical image by an image pickup means. The present invention relates to a light source device for irradiating illumination light toward an observation target portion in an image forming system for converting the signal into a signal and processing the signal for display on a display device.

[Prior Art] In recent years, endoscopes for medical use or the like have been used in which a solid-state imaging device such as a CCD is provided at the tip of the insertion portion. Since the insertion portion of the endoscope needs to be made as thin as possible, only one solid-state image sensor can be provided at the tip of the insertion portion, and this single element can provide a clear image. In order to obtain an image, the information of each color image of red, blue and green is taken out by a frame sequential method. Therefore, as the light source device in the electronic endoscope provided with this solid-state imaging device of the frame sequential method, a rotary color filter that transmits each wavelength region of red (R), green (G), and blue (B) is used. By interposing this rotating color filter in the optical path from the light source, rotating it, and sequentially irradiating the light in each wavelength region described above in time series, the image information of the three primary colors of R, G, B is obtained. To do so.

[Problems to be Solved by the Invention] By the way, in performing inspection / diagnosis using an endoscope, for example, information such as the position and shape of a lesion part may be obtained.
It is advantageous to obtain information on the contour shape of the lesion, and for this purpose, it is necessary to form image information based on infrared light. Further, R, G, B color filters arranged in a checkerboard pattern, when connecting an endoscope having a built-in solid-state imaging device with a so-called mosaic filter,
When displaying an image of an observation target part on a display device in monochrome, it may be necessary to illuminate with white light. Furthermore, in order to confirm up to which position in the patient's body the position of the tip of the insertion part is inserted, it is necessary to increase the amount of illumination light emitted from the tip of the insertion part as much as possible. is there.

However, in the light source device according to the above-mentioned conventional technique, as the rotary color filter interposed in the optical path from the light source, R, G, B three primary color filters are used, and when using a solid-state image sensor, In obtaining the image information of the three primary colors, the wavelength component of infrared light is harmful light, so it is necessary to remove it, and for this purpose, an infrared light cut filter is also used. Therefore, even if a filter that transmits infrared light is integrated into this three primary color filter,
Since the infrared light cut filter is interposed, the image information based on the infrared light cannot be acquired. Therefore, the illumination light in the wavelength region of infrared light cannot be continuously irradiated with the above-mentioned sequential illumination of the three primary colors of red, green, and blue, and it is difficult to obtain image information based on infrared light. Further, in order to perform illumination with white light, this rotary color filter must be removed from the optical path of the illumination light. For this purpose, a mechanism for inserting and removing this rotary color filter into the optical path is attached. Therefore, there is a problem that the structure of the light source device becomes complicated and becomes large in size.

The present invention has been made in view of the above points, the object is to R, G, B light in the wavelength region of infrared light
It is an object of the present invention to provide a light source device capable of irradiating an observation target portion together with the illumination of each color wavelength and easily illuminating with white light.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention is directed to an illumination light source and an optical path of illumination light from the illumination light source, and outputs red, green, and blue wavelength region lights, respectively. A first rotation color filter having each color transmission filter and each division section of a non-filter section to be transmitted, and a wavelength region of infrared light is reflected to three sections corresponding to the color transmission filter section of this first rotation color filter. A second rotary color filter having an infrared light cut filter portion and an infrared light transmitting filter portion for transmitting the infrared light wavelength region in a section corresponding to the non-filter region of the first rotary color filter; The first and second rotary color filters are driven to rotate at the same time, with each color transmission filter part overlapping the infrared light cut filter part and the non-filter part overlapping the infrared light transmission filter part. Color filter Filter rotation driving means capable of switching any one of the rotation color filters independently to a predetermined angle so that the non-filter portion overlaps the second rotation color filter with the infrared cut filter portion; The rotational position detecting means for detecting a predetermined position in the rotational direction of the second rotational color filter, and the two rotational color filters are simultaneously rotated by the filter rotational driving means to switch to a stopped state. Based on the signal from the rotational position detection means,
Either the non-filter part of the first rotary color filter or the infrared light cut filter part of the second rotary color filter is stopped at a position facing the optical path from the illumination light source, and either of these rotary color filters is stopped. And a control means for controlling the non-filter part of the first rotary color filter and the infrared light cut filter part of the second rotary color filter so as to be in a position facing the optical path. The feature is that it is configured.

[Operation] With the configuration as described above, the non-filter portion of the first rotary color filter is overlapped with the infrared light transmitting filter portion of the second rotary color filter, and the first color transmitting filter portions are separated from each other. In the state in which the infrared light cut filter portion of the second rotary color filter overlaps, both rotary color filters are simultaneously driven to rotate by the rotary drive means,
Illumination with red, blue, green, and infrared light occurs continuously in a time-sequential and periodic manner.

The rotation position detection means detects the rotation of either the first or second rotation color filter, and the control means determines the first and second rotation color filters based on the signal from the rotation position detection means. It will stop at the angular position. Then, in the control means, by rotating one rotational color filter from this state by a predetermined angle, the non-filter portion in the first rotational color filter and the infrared cut filter portion in the second rotational color filter are in the optical path. It will be displaced to the facing position. As a result, the light from which the infrared light has been removed passes through this rotary color filter, and white light can be illuminated with a large amount of light.

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

First, FIG. 1 shows a basic configuration of a light source device according to the present invention. In the figure, 1 denotes a light source device, 2 denotes an endoscope, and the light source device 1 has a built-in light source 10 including a lamp or the like that emits light in a visible region and an infrared region. The illumination light from the light source 10 is emitted from the light guide 11
Is transmitted to the tip of the insertion portion 2a of the endoscope 2 via
The observation target part is illuminated.

Next, a filter device 20 is interposed between the light source 10 and the light guide 11. This filter device 20 includes first and second rotary color filters 21 and 2 formed in the shape of two disks.
2, the rotary color filters 21 and 22 are driven to rotate by a motor 23. Here, the rotary color filters 21 and 22 are configured as shown in FIGS. 2 (a) and 2 (b).

First, as is apparent from FIG. 2 (a), the first rotary color filter 21 has a fan shape 21a to 21d having a central angle of 90 °.
The first partition 21a is a red filter section equipped with a filter that transmits light in the red (R) wavelength region, and the second partition 21b is green (G) wavelength. The third filter 21c, which is a green filter section equipped with a filter that transmits regional light, is a blue filter section, which is equipped with a filter that transmits light in the blue (B) wavelength region.
Reference numeral d denotes a non-filter portion that does not have a filter function, and glass or the like is attached to this portion or it is held in a spatial state. Here, as will be described later, when illuminating with infrared light, when using far infrared light,
Do not attach glass etc.

Further, as is apparent from FIG. 2B, the second rotary color filter 22 includes an infrared light cut filter portion 22a that cuts infrared light (IR) and a red light that transmits the infrared light wavelength region. The external light filter section 22b is formed, and when the second rotary color filter 22 is divided into four fan-shaped sections having an angle of 90 °, the infrared light cut filter section 22a is divided into three sections, that is, The infrared light filter portion 22b occupies a 3/4 portion, and the infrared light filter portion 22b is a remaining one section, that is, a ¼ portion.

A motor 23 is provided as a rotation driving means for rotating the rotation color filters 21 and 22 configured as described above.
The motor 23 is capable of rotating both the rotary color filters 21 and 22 at the same time, and the second rotary color filter 22 alone. When they are driven to rotate at the same time, the non-filter portion 21d of the first rotary color filter 21 faces the infrared light transmitting filter portion 22b of the second rotary color filter 22. Further, after the rotation is stopped, the second rotary color filter 22 is rotated by a predetermined angle, and the non-filter portion 21 of the first rotary color filter 21 is rotated.
The d is made to face the infrared light cut filter portion 22a, and this portion is positioned in the optical path from the light source 10.

In this way, in order to switch between the state in which both rotary color filters 21 and 22 are simultaneously rotated and the state in which the second rotary color filter 22 is rotated relative to the first rotary color filter 21, the second The rotary color filter 22 of the motor 23 rotary shaft 24
The first rotary color filter 21 is connected to the rotary shaft 24 via a contact / separation mechanism so that the first rotary color filter 21 can be contacted / separated.

That is, the first rotary color filter 21 is attached to the driven cylinder 25, and the spring 26 acts on the driven cylinder 25 so that the driven cylinder 25 is pressed in the direction indicated by the arrow A in FIG. There is. In this state, the driven cylinder 25 is adapted to engage with the rotary shaft 24 and rotate integrally therewith. When the actuator (not shown) such as a solenoid is slid in the direction of arrow B in FIG.
When the engagement state with 24 is released and the motor 23 is rotated in this state, even if the second rotary color filter 22 is rotated,
The driven cylinder 25 and the first rotary color filter attached to it.
21 will be held in a non-rotating state.

Here, the motor 23 is connected to a motor drive control circuit 27 in order to control the rotation of the rotary color filters 21 and 22, and the drive thereof is controlled based on a signal from the motor drive control circuit 27. Further, when the rotary color filters 21 and 22 are stopped from being rotated at the same time, first, the non-filter portion 21d of the first rotary color filter 21 must be positioned so as to face the optical path from the light source 10. For this reason, the second rotary color filter 22 has a position index 28
In order to detect the position of this position index 28, a detection sensor 29 as a filter rotation position detection means is arranged so as to face the rotation locus thereof.

As a result, when the motor drive control circuit 27 outputs a stop signal to the motor 23, the second rotary color filter 22
When the position index 28 is detected by the detection sensor 29, both rotary color filters 21 and 22 are stopped. Then, in this state, based on the signal from the motor drive control circuit 27, first, the engagement between the driven cylinder 25 and the rotary shaft 24 is released, and then the motor 23 is operated and the second rotation color is generated. Only the filter 22 can be rotated 90 °.

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

First, the non-filter portion of the first rotary color filter 21 is the infrared light transmitting filter portion 22b of the second rotary color filter 22.
The red, green, and blue filter portions 21a to 21c face the infrared light cut filter portion 22a. In this state, the motor 23 is operated based on the signal from the motor drive control circuit 27.

As a result, as shown in FIG. 3, the red filter section is
When the light 21a is located on the optical path from the light source 10, the light having only the red wavelength component of the illumination light is transmitted and sent to the light guide 12, as shown in FIG. Next, when the green filter portion 21b is located in the optical path,
As shown in (b), light having only a green wavelength component is transmitted, and when the blue filter portion 21c is located in the optical path, it has only a blue wavelength component as shown in (a). Light will be transmitted. As a result, the three primary colors can be sequentially illuminated. Moreover, each of the filter parts 21a to 21c in the first rotary color filter 21 includes the infrared light cut filter part in the second rotary color filter 22.
Since 22a faces each other, it is possible to reliably cut off harmful infrared light in forming an image signal even if it is irradiated with light containing a large amount of infrared light, and the wavelength characteristic of the transmitted light is It will be extremely good. In addition to this, the first rotary color filter 21
When the non-filter part 21d in is located in the optical path from the light source 10, the infrared light transmitting filter part 22b of the second rotary color filter 22 is located in this optical path.
As described above, light having only the wavelength component of infrared light can be transmitted.

Therefore, the light guide 11 has red (R), green (G),
Illumination light of blue (B) and infrared light (IR) can be periodically emitted at regular time intervals.

Then, the rotary color filters 21, 2 in the filter device 20.
In order to stop the rotation of 2, the operation stop signal is output from the motor drive control circuit 27 to the motor 23. Based on this, the detection sensor 29 is activated and the second rotary color filter 22 is activated.
When the position index 28 provided at the position is detected, the first rotary color filters 21 and 22 are stopped. As a result, the non-filter portion 21d of the first rotary color filter 21 stops at the position facing the optical path from the light source 10. After that, the driven cylinder 25 slides and displaces in the direction of arrow B in FIG. 1 against the biasing force of the spring 26, and the engagement between the driven cylinder 25 and the rotary shaft 24 is released. To be In this state, the motor 23 is started again and only the second rotary color filter 22 is rotated by 90 °, so that the non-filter portion 21 of the first rotary color filter 21 is rotated.
The infrared light cut filter unit 2 of the second rotary color filter 22 is shown in d.
Face 2a.

As a result, as shown in (e) of FIG. 3, the light guide 11 receives the white light (R +
Illumination by G + B) can be performed. Here, since the amount of this illumination light is large, in the state where the insertion portion 2a of the endoscope 2 is inserted into the body, the position of the distal end portion should be confirmed from outside the body by the light leaking through the body skin. You can

Next, an example of an image forming system for forming an image of the observation target part in a state where the observation target part is illuminated by the light source device as described above will be described with reference to FIG.

In the figure, 30 is a solid-state image sensor such as CCD, 31 is a processor, 32 is a display device, respectively, the image signal from the solid-state image sensor 30 is transmitted to the processor 31,
After performing predetermined signal processing by the processor 31,
It is adapted to be displayed on the display device 32.

That is, the image signal of the observation target portion obtained by photoelectric conversion by the solid-state imaging device 30 is selectively input to either the frame sequential processing unit 34 or the non-plane sequential processing unit 35 by the switching unit 33. Here, the frame sequential processing unit 34 and the non-frame sequential processing unit
Switching between 35 and 35 will be automatically switched by the above-mentioned lighting method. When the sequential illumination of R, G, B, and IR by the rotation of the rotary color filters 21, 22 is performed, the field sequential processing unit 34 is selected, the rotation of the rotary color filters 21, 22 is stopped, When the illumination is performed by R + G + B that does not include infrared light, the non-plane sequential processing unit 35 is selected.

Thus, the solid-state imaging device 30 is used to obtain the time-division
The R, G, B, and IR color image signals are sequentially input to the frame sequential processing section 34 by applying a clock pulse to the solid-state image sensor 30 and driving the solid-state image sensor 30, and these color image signals are A /
The color image signals are input to the D converter 36 and converted into digital signals. And this signal is a switching means
Selected by 37, data of each color image is written in the frame memory. Here, the frame memory is
In order to store each color image signal of R, G, B, IR, 38
It has four memories of R, 38G, 38B and 38IR, and a D / A converter 39 for analog-converting this memory output is connected to the output side of each of these frame memories. Then, the R, G, and B color image signals from the frame memories 38R, 38G, and 38B are simultaneously read by the color composite signal generation encoder 40, and displayed on the display device 32 via the display mode selection switch. . The color image signals are also input to the dual screen processing circuit 42.

Next, the infrared image data from the frame memory 38IR is
It is displayed on the display device 32 as it is via the display mode selection switch 41, or is input to the two-screen processing circuit 42 together with the above-mentioned color image signals, and is displayed on the display device 32 by the output from the two-screen processing circuit 42. It is also possible to display two screens of color image and IR image side by side. Here, the IR image displays data regarding the heat distribution of the observation target portion, and the position and shape of the lesion portion are displayed by this.

Furthermore, each of the R, G, B, and IR image signals described above is also input to the IR signal amplifier 43, and the IR partition gate pulse is input to the IR signal amplifier 43 to extract only the IR image signal and
The contour binarization circuit 44 obtains an IR contour shape signal. Then, by inputting this signal to the encoder 40 for generating a color composite signal, it is possible to superimpose IR contour information such as the contour line of the lesion on the above-mentioned color image. Whether or not to superimpose the IR contour information 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, it can be displayed on the display device 32 by the display mode selection switch 41. Therefore, the non-sequential processing unit 35 is a processing circuit suitable for signal processing from another type of image sensor capable of forming a color image signal by illuminating with white light, for example, a CCD with a mosaic filter built-in. Or
If a processing circuit suitable for forming a monochrome image is provided, the processor 34 has a mosaic filter built-in CCD when illuminating with white light.
It becomes possible to connect an endoscope provided with the above and to display an image of the observation target portion on a monochrome screen.

[Effects of the Invention] As described above, according to the present invention, two rotary color filters are used, and the first rotary color filter transmits each color transmission filter part of each wavelength region of red, green, and blue. And a non-filter portion, and the second rotary color filter is provided with three infrared light cut filter portions and one infrared light transmission filter portion that transmits one infrared light wavelength region. Driving both rotary color filters simultaneously while the non-filter portion of the rotary color filter and the infrared light transmitting filter portion of the second rotary color filter overlap each other and each color filter portion overlaps the infrared light cut filter portion. This makes it possible to sequentially generate illumination light of red, blue, green, and infrared wavelength regions, and when rotation is stopped, rotate one rotating color filter relative to the other to make the first rotation. Non-color filter Filter part and the infrared light cut filter part of the second rotary color filter can be made to face the optical path of the illumination light. Therefore, without providing a mechanism for inserting and removing the rotary color filter into the optical path, the three primary colors are sequentially used. It is possible to switch between illumination and illumination with white light, and when performing sequential illumination of the three primary colors, harmful infrared light is cut off when illuminated with each wavelength of red, green and blue and when illuminated with white light. As a result, various effects such as the wavelength characteristics of the respective transmitted light being remarkably improved are exhibited.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a structural explanatory view of a light source device, FIGS. 2A and 2B are structural explanatory views of different rotary color filters, and FIG. FIG. 4 is a circuit diagram of the image forming system. 1: Light source device, 2: Endoscope, 10: Light source, 11: Light guide, 2
0: Filter device, 21, 22: Rotation color filter, 21a: Red filter part, 21b: Green filter part, 21c: Blue filter part, 21d: Non-filter part, 22a: Infrared light cut filter part, 22b: Infrared Optical filter unit, 23: motor, 24: rotary shaft, 25: driven cylinder, 26: spring, 27: motor drive control circuit, 28: position index, 2
9: Detection sensor, 30: Solid-state image sensor, 31: Processor, 32:
Display device.

Claims (1)

[Claims] 1. An illuminating light source and an illuminating light path from the illuminating light source are exposed to red,
A first rotary color filter having color filter sections and non-filter section sections that transmit light of each wavelength region of green and blue, and three sections corresponding to the color filter section of the first rotary color filter. In addition, an infrared light cut filter portion that reflects the infrared light wavelength region and an infrared light transmission filter portion that transmits the infrared light wavelength region are provided in a section corresponding to the non-filter region of the first rotary color filter. The second rotary color filter and the first and second rotary color filters are arranged so that each color transmission filter section overlaps with the infrared light cut filter section and the non-filter section overlaps with the infrared light transmission filter section. One of the rotary color filters is independently rotated by a predetermined angle so that the non-filter portion of the first rotary color filter and the second rotary color filter overlap the infrared cut filter portion in a state of being rotationally driven. Rotation driving means capable of switching to a state, rotation position detecting means for detecting a predetermined position in the rotation direction of the first or second rotation color filter, and both rotation color filters by the filter rotation driving means. When switching from the state where is rotating at the same time to the stopped state,
Based on the signal from the rotational position detecting means, the first
Of the rotary color filter is stopped at a position where the non-filter part of the rotary color filter or the infrared light cut filter part of the second rotary color filter faces the optical path from the illumination light source, and either of the rotary color filters is set to a predetermined position. A configuration is provided in which the non-filter portion of the first rotary color filter and the infrared light cut filter portion of the second rotary color filter are controlled to rotate to an angle so as to be positioned so as to face the optical path. A light source device characterized by the above.