JP5455856B2 - Temperature control device, temperature control method, light source device, and endoscope diagnosis device - Google Patents

Description

  The present invention relates to white light observation (normal light observation) for imaging and observing an observation area of a subject using white light (normal light), and to the observation area of a subject using narrowband light of a predetermined band. Endoscope diagnostic apparatus that selectively switches between special light observation for imaging and observation, a light source device that emits illumination light used in the endoscope diagnostic apparatus, and a laser used in the light source apparatus The present invention relates to a temperature adjusting device and a temperature adjusting method for a light source.

  Conventionally, illumination light such as white light emitted from a light source device is guided to the distal end of the endoscope to irradiate the observation area of the subject, and the reflected light is imaged to obtain a white light image. An endoscope apparatus that performs observation is used.

  On the other hand, in recent years, in addition to white light observation, narrow band light of a predetermined band is irradiated to the observation region of the subject, and the reflected light is imaged to obtain a narrow band light image, so that the desired tissue can be obtained. An endoscopic device that performs special light observation that obtains tissue information of a certain depth is used (see Patent Document 1).

  Here, it is known that the depth of light in the depth direction with respect to a living tissue depends on the wavelength of the light. That is, blue (B) light having a short wavelength reaches only near the surface tissue due to absorption characteristics and scattering characteristics in the living tissue. Further, green (G) light having a wavelength longer than that of B light reaches a surface layer structure and a middle layer structure deeper than that of B light, and red (R) light having a wavelength longer than that of G light is further increased than that of G light. Reach deep deep and deep tissue.

  That is, the image signals obtained by irradiating the observation region of the subject with each of the B light, the G light, and the R light and receiving the reflected light by the image sensor mainly include information on the surface layer tissue, Includes information on the surface layer structure, information on the deep layer structure, and information on the middle layer structure.

  In an endoscopic device that performs special light observation, biological information that cannot be obtained with normal observation images, such as the fine structure of new blood vessels occurring in the mucosa layer or submucosa in the body cavity of the subject, enhancement of lesions, etc. can be easily obtained. Can be visualized. For example, if the observation target is a cancerous lesion, irradiating the mucosal tissue with blue narrow-band light allows more detailed observation of the state of microvessels and microstructures on the surface of the tissue. Can do.

  Here, there is one that uses a laser light source as a light source of illumination light emitted from the endoscope diagnosis apparatus. However, it is known that the laser light source has problems such as self-heating and fluctuations in drive current-output light quantity characteristics according to temperature changes.

  FIG. 8 is a graph showing an example of the drive current-output light quantity characteristic of the laser light source. The horizontal axis of the graph is the drive current I, and the vertical axis is the output light amount (light emission amount) L. As shown in this graph, the laser light source starts to emit light with a predetermined drive current as a threshold value, and thereafter, as the drive current increases, the output light amount increases in a linear function in proportion to the drive current. It has drive current-output light quantity characteristics.

  Further, when the temperature of the laser light source rises by ΔT from T (+ ΔT), the output light amount at the time of the drive current I decreases (−ΔL) by ΔL. On the other hand, when the temperature falls from ΔT by ΔT (−ΔT), the output light amount at the time of the drive current I rises by ΔL (+ ΔL).

  For example, when the drive current I1 and the temperature T are L1, the output light quantity is L1, the drive current I2 (I1> I2), the output light quantity at the temperature T is L2 (L1> L2), and the output when the temperature is shifted by ΔT. Let ΔL be the error in the amount of light. In this case, the output light amount error at the output light amount L1 is IΔL / L1, and the output light amount error at the output light amount L2 is IΔL / L2. Accordingly, the output light amount error becomes a large error when the output light amount is low and the light amount is low.

  As for the laser light source used in the light source device of the endoscope diagnosis apparatus, for example, ON / OFF of a plurality of laser light sources and the light emission amount are frequently switched. Therefore, when using a laser light source, it is necessary to adjust the temperature of the laser light source.

  FIG. 9 is a conceptual diagram illustrating an example of a configuration of a temperature adjustment device for a laser light source. The temperature adjusting device 94 shown in the figure is used in a light source device having four laser light sources (LD) 86a, 86b, 86c, 86d, and corresponds to each laser light source 86a, 86b, 86c, 86d. Laser fixing plates 88a, 88b, 88c, 88d, temperature control elements 90a, 90b, 90c, 90d, and heat radiation plates 92a, 92b, 92c, 92d.

  Hereinafter, the laser light source 86a at the left end in the drawing will be representatively described, but the same applies to the other laser light sources 86b, 86c, and 86d.

  The laser light source 86a is disposed on the upper surface of the laser fixing plate 88a in the drawing. The temperature adjusting element 90a is a Peltier element that adjusts the laser light source 86a to a predetermined temperature by adjusting the laser fixing plate 88a to a predetermined temperature, and the laser is adjusted so that the cooling surface is in contact with the lower surface of the laser fixing plate 88a. It is arranged on the lower surface of the fixed plate 88a. A heat radiating plate 92a is attached to the heat generating surface of the temperature control element 90a so as to dissipate heat.

  In the temperature adjusting device 94, the temperature of the laser fixing plate 88a is adjusted by the temperature adjusting element 90a, so that the laser fixing plate 88a and consequently the laser light source 86a are adjusted to a predetermined temperature. Since the temperature adjusting device 94 can independently adjust the temperatures of the respective laser light sources 86a, 86b, 86c, 86d, there is an advantage that the temperature can be adjusted accurately. However, there are problems such as an increase in the size of the apparatus, an increase in power consumption, an increase in cost, and difficulty in control.

  Here, the present applicant has proposed a light source device disclosed in Patent Document 2 that adjusts the amount of illumination light as a prior art document relevant to the present invention.

  The light source device disclosed in the same document is a light source device that generates fluorescent light by exciting a phosphor with excitation light emitted from a laser light source or the like, and obtains white illumination light by mixing excitation light and fluorescence. A specific drive current to the light source, and by increasing or decreasing either the number, magnitude, or time of the drive current in a certain period, the ratio of fluorescence to the illumination light is changed, and the integration of the illumination light in a certain period It corrects variations in light quantity and chromaticity.

  In addition, this document describes that the temperature of the light source is controlled by a Peltier element or the like to suppress a change in the temperature of the light source accompanying a change in the drive current, and hence a change in the oscillation wavelength of the excitation light due to a temperature change in the light source. ing.

JP 2002-34893 A JP 2009-56248 A

An object of the present invention is to reduce temperature variations between laser light sources and reduce light emission variations between laser light sources even when on / off of a plurality of laser light sources is frequently switched.
Another object of the present invention is to make it possible to reduce the size, power consumption, and cost of the apparatus, and to easily control the temperature adjusting device and the temperature adjusting method, the light source device using this temperature adjusting device, and Another object of the present invention is to provide an endoscope diagnostic apparatus that uses this light source device.

In order to achieve the above object, the present invention includes two or more first laser light sources and one or more second laser light sources whose light amounts are controlled separately from the first laser light sources. A temperature control device used in a light source device in which the amount of light of the second laser light source is controlled at an arbitrary ratio,
A laser fixing plate in which the first laser light sources are arranged in a row at the center of one surface, and the second laser light sources are arranged in a row outside the arrangement direction of the first laser light sources;
A temperature control element disposed at the center of the other surface of the laser fixing plate;
A temperature sensing element disposed between the first and second laser light sources and the temperature control element;
The ratio of the thermal resistance between the temperature control element and the temperature detection element, the thermal resistance between the temperature detection element and the first laser light source, and the temperature control element and the second laser light source A predetermined fixed interval between the first laser light source and the second laser light source so that a ratio of a thermal resistance between the first laser light source and a thermal resistance between the second laser light source and the first laser light source is equal. The temperature adjusting device is characterized in that the laser fixing plate is formed in a predetermined shape.

  Here, it is preferable that the first laser light source has a larger amount of heat generation than the second laser light source when the light amount is the same.

  The first laser light source preferably has a light emission ratio smaller than that of the second laser light source when both the first and second laser light sources are turned on.

  The first laser light source preferably emits laser light having a central wavelength of 445 nm, and the second laser light source preferably emits laser light having a central wavelength of 405 nm.

  Further, it is preferable that the predetermined shape of the laser fixing plate is a groove portion or a mountain portion formed in a region between the first laser light source and the second laser light source.

  The temperature control element is preferably a Peltier element.

The present invention further includes two or more first laser light sources and one or more second laser light sources whose light amounts are controlled separately from the first laser light sources, and the light amounts of the first and second laser light sources. Is a temperature adjustment method applied to a light source device controlled at an arbitrary ratio,
The first laser light sources are arranged in a row at the center of one surface of the laser fixing plate, and the second laser light sources are arranged in a row outside the arrangement direction of the first laser light sources,
A temperature control element is arranged at the center of the other surface of the laser fixing plate,
A temperature measuring element is disposed between the first laser light source and the temperature control element;
The ratio of the thermal resistance between the temperature control element and the temperature detection element, the thermal resistance between the temperature detection element and the first laser light source, and the temperature control element and the second laser light source A predetermined fixed interval between the first laser light source and the second laser light source so that a ratio between a thermal resistance between the second laser light source and the first laser light source is equal. And the laser fixing plate is formed in a predetermined shape.

  Here, it is preferable that the first laser light source has a larger amount of heat generation than the second laser light source when the light amount is the same.

  The first laser light source preferably has a light emission ratio smaller than that of the second laser light source when both the first and second laser light sources are turned on.

  Further, it is preferable that the predetermined shape of the laser fixing plate is a groove portion or a mountain portion formed in a region between the first laser light source and the second laser light source.

Further, the present invention is a light source device that emits illumination light used in an endoscope diagnostic apparatus,
Two or more first laser light sources;
One or more second laser light sources whose light amounts are controlled separately from the first laser light source;
A temperature control device according to any of the above,
There is provided a light source device comprising a light amount control unit that performs on / off control and light amount control of the first and second laser light sources.

The present invention also provides a light source device as described above,
An endoscope apparatus that captures an endoscopic image of an observation region of a subject using illumination light emitted from the light source device;
A processor device for performing image processing on an endoscopic image captured by the endoscopic device;
An endoscope diagnostic apparatus comprising: a display device that displays an endoscopic image subjected to image processing by the processor device.

  According to the present invention, with the above configuration, the first and second laser light sources can be adjusted to a predetermined temperature, the observation mode is frequently switched, and the plurality of laser light sources are frequently switched on and off. Even in such a case, it is possible to output laser light having a predetermined light emission amount from each laser light source. Thereby, it is possible to prevent the amount of illumination light from varying, and it is possible to improve the quality of an endoscope image to be picked up.

  In addition, according to the present invention, since the temperature control device needs only one laser fixing plate and one temperature control element for each of the plurality of laser light sources, the device can be downsized, the power consumption can be reduced, and the cost can be reduced. Is possible. In addition, each laser light source can be adjusted to a predetermined temperature simply by adjusting the temperature at the position of the temperature measuring element to a predetermined temperature, so that there is an advantage that control is easy.

1 is an external view of an embodiment showing a configuration of an endoscope diagnostic apparatus of the present invention. It is a block diagram showing the internal structure of the endoscope diagnostic apparatus shown in FIG. It is a graph which shows the emission spectrum which wavelength-converted blue laser beam and blue laser beam with the fluorescent substance. It is a conceptual diagram of one Embodiment showing the structure of the temperature control apparatus of a laser light source. (A) And (B) is a conceptual diagram showing the structure of the groove part and peak part formed in the area | region between a white light source and a narrow-band light source of a laser fixing plate. It is a graph of one Embodiment showing the drive current-output light quantity characteristic of a white light source. It is a graph of one Embodiment showing the drive current-output light quantity characteristic of a narrow-band light source. It is a graph of an example showing the drive current-output light quantity characteristic of a laser light source. It is a conceptual diagram of an example showing the structure of the temperature control apparatus of a laser light source.

  Hereinafter, based on preferred embodiments shown in the accompanying drawings, a temperature adjustment device, a temperature adjustment method, a light source device, and an endoscope diagnosis device according to the present invention will be described in detail.

  FIG. 1 is an external view of an embodiment showing the configuration of the endoscope diagnosis apparatus of the present invention, and FIG. 2 is a block diagram showing the internal configuration thereof. The endoscope diagnostic apparatus 10 shown in these drawings images a subject observation region using a light source device 12 that generates illumination light and illumination light emitted from the light source device 12, and outputs an image signal thereof. An endoscope device 14; a processor device 16 that performs image processing on an image signal from the endoscope device 14 and outputs an endoscope image; a display device 18 that displays an endoscope image from the processor device 16; It is comprised with the input device 20 which receives input operation.

  Here, the endoscope diagnosis apparatus 10 irradiates a subject with white light, captures the reflected light, and displays (observes) a white light image, and a narrow band of white light and a predetermined band. A special light observation mode that irradiates a subject with combined light (special light) with light, images the reflected light, and displays a composite image (special light image) of a white light image and a narrow-band light image . The special light observation mode includes, for example, fluorescence observation and infrared light observation in addition to narrow-band light observation. Each observation mode is appropriately switched based on an instruction input from the changeover switch 64 or the input device 20 of the endoscope apparatus 14.

  The light source device 12 emits two systems of illumination light, and serves as a first illumination optical system. The white light source 22a, the narrow-band light source 24a, a condenser lens and an optical fiber (not shown), and multiplexing A white light source 22b, a narrow-band light source 24b, a condenser lens and an optical fiber (not shown), a multiplexer 28b, an optical fiber 30b, and a light quantity. A control unit 26 and a temperature adjustment device 72 are provided. Since the first and second illumination optical systems have the same configuration and operation, the first illumination optical system will be mainly described below.

  As will be described in detail later, the white light source 22a emits white light observation excitation light for generating white light (pseudo white light) from the phosphor 52a disposed at the endoscope distal end portion. In the present embodiment, a blue laser light source that emits narrow band light having a central wavelength of 445 nm is used as the white light source 22a. The white light source 22a is not limited to emitting excitation light for emitting white light in combination with the phosphor 52a, but may be any light source that can emit white light from the distal end portion of the endoscope.

  The narrow-band light source 24a emits narrow-band light for special light observation that serves as illumination light for obtaining tissue information at a desired depth in the observation region of the subject. In the present embodiment, a blue-violet laser light source that emits narrow-band light having a central wavelength of 405 nm for observing the surface tissue of the observation region of the subject is used as the narrow-band light source 24a. The center wavelength of the narrowband light emitted from the narrowband light source 24a is determined depending on whether the surface layer tissue, middle layer tissue, or deep layer tissue in the observation region of the subject is observed.

  As described above, it is known that the depth of light in the depth direction with respect to a living tissue depends on the wavelength of light. Blood vessel information from capillary blood vessels on the surface of the mucosa is obtained when the illumination light is in the wavelength region near 400 nm, and blood vessel information including deeper blood vessels is obtained in the wavelength region near the wavelength of 500 nm. Therefore, a light source with a central wavelength of 360 to 800 nm, preferably 365 to 515 nm, is used for blood vessel observation of living tissue, and a light source with a central wavelength of 360 to 470 nm, preferably 360 to 450 nm, is used for observation of surface blood vessels. It is done.

  As the blue laser light source and the blue-violet laser light source, semiconductor light emitting devices such as a broad area type InGaN laser diode, InGaNAs laser diode, and GaNAs laser diode can be used.

  The light amount control unit 26 performs on / off control and light amount control of the white light sources 22a and 22b and the narrow band light sources 24a and 24b under the control of the control unit 66 of the processor device 16 to be described later. In the present embodiment, the white light sources 22a and 22b are controlled to have the same light amount, and the narrow-band light sources 24a and 24b are controlled to have the same light amount separately from the white light sources 22a and 22b. The light amounts of the white light sources 22a and 22b and the narrow band light sources 24a and 24b are controlled at an arbitrary ratio.

  The temperature adjusting device 72 adjusts the laser light source including the white light source 22a22b and the narrow-band light sources 24a and 24b to a predetermined temperature. Details of the temperature control device 72 will be described later.

  The optical fiber 30a is a multimode fiber, and as an example, a thin fiber cable having a core diameter of 105 μm, a cladding diameter of 125 μm, and a diameter including a protective layer as an outer shell of φ0.3 to 0.5 mm may be used. it can.

  In the first illumination optical system, the laser light emitted from each of the light sources 22a and 24a is collected by a condenser lens, is input to the multiplexer 28a via an optical fiber, and is multiplexed by the multiplexer 28a. The Then, the multiplexed light output from the multiplexer 28a is propagated to the connector portion 36A via the optical fiber 30a, and is incident on the incident end of the optical fiber 54a of the endoscope apparatus 14 described later.

  The light source device 12 is controlled by the control unit 66 of the processor device 16 according to the observation mode, or the white light observation excitation light emitted from the white light source 22a, or the white light observation excitation light and the narrow-band light source. The combined light with the narrow band light for special light observation emitted from 24a is output. That is, the light source device 12 outputs excitation light for white light observation in the white light observation mode, and excitation light for white light observation and narrow band light for special light observation in the special light observation mode. The combined light is output.

  The same applies to the second illumination optical system. The first and second illumination optical systems operate basically simultaneously. That is, equivalent illumination light is simultaneously output from the first and second illumination optical systems.

  In the present embodiment, in the special light observation mode, the combined light of the excitation light for white light observation and the narrow band light for special light observation is applied to the phosphor 52a. However, the present invention is not limited to this. Not. For example, the light is guided to the distal end of the endoscope by two systems of optical fibers without being multiplexed, and the phosphor 52a is irradiated with excitation light for white light observation, and narrow band light for special light observation. May be directly applied to the observation region of the subject from the distal end portion of the endoscope.

  Further, in the special light observation mode, the blue laser light source and the blue-violet laser light source may not be turned on at the same time, but may be turned on alternately within a light receiving period within one frame of the image sensor, for example. In this case, it can contribute to power saving and suppression of heat generation.

  Subsequently, the endoscope apparatus 14 includes an illumination optical system that irradiates the observation area with two systems of illumination light from the tip of the endoscope insertion portion 32 that is inserted into the subject, and reflected light from the observation area. And an imaging optical system for imaging The endoscope apparatus 14 includes an endoscope insertion section 32, an operation section 34 that performs an operation for bending and observing the distal end of the endoscope insertion section 32, and the endoscope apparatus 14 as a light source device 12 and a processor. Connector portions 36A and 36B that are detachably connected to the device 16 are provided.

  The endoscope insertion portion 32 includes a flexible soft portion 38, a bending portion 40, and a distal end portion (hereinafter also referred to as an endoscope distal end portion) 42.

  The bending portion 40 is provided between the flexible portion 38 and the distal end portion 42 and is configured to be bent by a turning operation of an angle knob 44 disposed in the operation portion 34. The bending portion 40 can be bent in an arbitrary direction and an arbitrary angle according to a part of a subject in which the endoscope apparatus 14 is used, and the observation of the irradiation window 46 and the imaging element of the endoscope distal end portion 42. The direction can be directed to the desired observation site.

  As shown in FIG. 2, the endoscope distal end portion 42 has two systems of irradiation windows 46 a and 46 b for irradiating light to the observation region, and an observation window for imaging reflected light from the observation region. 48 is arranged.

  An optical system such as a lens 50a is attached to the back of the irradiation window 46a, and a phosphor 52a is disposed in the back, and an optical fiber 54a is housed in the back of the phosphor 52a. The optical fiber 54a is laid from the light source device 12 to the endoscope distal end portion 42 via the connector portion 36A. Similarly, a lens 50b, a phosphor 52b, and an optical fiber 54b are disposed in the back of the irradiation window 46b. Since the former and the latter illumination optical systems have the same configuration and operation, the former illumination optical system will be mainly described below.

The phosphor 52a absorbs a part of the blue laser light from the blue laser light source 22a and emits green to yellow excitation light (for example, YAG-based fluorescent material or BAM (BaMgAl ₁₀ O ₁₇ )). (Fluorescent substance). When the phosphor 52a is irradiated with excitation light for white light observation, green to yellow excitation emission light using blue laser light as excitation light for white light observation, and a blue laser transmitted without being absorbed by the phosphor 52a. Combined with light, white light (pseudo white light) is generated. By using a semiconductor light emitting element as a light source for excitation light for white light observation as in this configuration example, high intensity white light can be obtained with high luminous efficiency, and the intensity of white light can be easily adjusted. Changes in the color temperature and chromaticity of light can be kept small.

  The phosphor 52a can prevent the occurrence of flickering when performing moving image display due to speckles generated due to the coherence of the laser light, which may cause noise superimposition. In addition, the phosphor 52a takes into account the difference in refractive index between the phosphor constituting the phosphor 52a and the fixing / solidifying resin serving as the filler, and the particle size of the phosphor itself and the filler is set in the infrared region. It is preferable to use a material that absorbs light little and scatters a lot. This enhances the scattering effect without reducing the light intensity for red or infrared light, and reduces the optical loss.

  FIG. 3 is a graph showing a blue-violet laser light from a blue-violet laser light source, and a blue laser light from a blue laser light source and an emission spectrum obtained by wavelength-converting the blue laser light with a phosphor. Blue-violet laser light is represented by a bright line (profile A) having a center wavelength of 405 nm. The blue laser light is represented by a bright line having a center wavelength of 445 nm, and the excitation light emitted from the phosphor 52a by the blue laser light has a spectral intensity distribution in which the emission intensity increases in a wavelength band of about 450 nm to 700 nm. The pseudo white light described above is formed by the profile B of the excitation light and the blue laser light.

  Here, the white light referred to in the present invention is not limited to the one that strictly includes all the wavelength components of visible light. For example, the above-described pseudo white light and the reference colors R (red) and G ( Any material including light in a specific wavelength band such as green and B (blue) may be used. That is, the white light referred to in the present invention broadly includes, for example, light including a wavelength component from green to red, light including a wavelength component from blue to green, and the like.

  In the endoscope diagnostic apparatus 10, only the light of the profile B is used in the white light observation mode, and the light on which the profiles A and B are superimposed is used in the special light observation mode.

  That is, in the white light observation mode, the excitation light for white light observation emitted from the light source device 12 is guided to the phosphor 52a of the endoscope distal end portion 42 by the optical fiber 54a. As a result, white light is emitted from the phosphor 52a, and is irradiated onto the observation region of the subject from the irradiation window 46a via the lens 50a. In the special light observation mode, white light is emitted from the phosphor 52a by the combined light of the excitation light for white light observation emitted from the light source device 12 and the narrow band light for special light observation, and for special light observation. Of the narrow-band light is transmitted through the phosphor 52a, and is irradiated from the irradiation window 46a to the observation region of the subject through the lens 50a.

  The same applies to the latter illumination optical system. The first and second illumination optical systems operate basically simultaneously. That is, equivalent illumination light is simultaneously output from the first and second illumination optical systems.

  Subsequently, an optical system such as an objective lens unit 56 for capturing image light of the observation region of the subject is attached to the back of the observation window 48, and further, an image of the observation region of the subject is further provided behind the observation window 48. An image sensor 58 such as a charge coupled device (CCD) image sensor or a complementary metal-oxide semiconductor (CMOS) image sensor for acquiring information is attached.

  The image sensor used in the present invention may be a color image sensor for obtaining image signals of three colors R, G, and B, a so-called RGB image sensor provided with an RGB filter on the imaging surface, A so-called complementary color image sensor having C (cyan), M (magenta), Y (yellow), and G complementary color filters on the imaging surface may be used. In the case of a complementary color image sensor, RGB three-color image signals can be obtained by color conversion from four CMYG image signals. Therefore, in this case, the color conversion means for performing color conversion from the CMYG four-color image signal to the RGB three-color image signal is any one of the imaging portion of the endoscope device 14, the light source device 12, and the processor device 16. It is necessary to prepare for.

  Here, in the white light observation mode, the reflected light from the observation region of the subject irradiated with white light is collected by the objective lens unit 56, and a white light image is captured by the imaging element 58. In the special light observation mode, the reflected light from the observation region of the subject irradiated with the combined light of the white light and the narrow light for special light observation is condensed by the objective lens unit 56 and is collected by the imaging element 58. Then, a special light image in which the white light image and the special light image are superimposed is captured.

  An image signal (analog signal) of a white light image or special light image output from the image sensor 58 is input to the A / D converter 62 through the scope cable 60. The A / D converter 62 performs analog / digital conversion on the image signal (analog signal) from the image sensor 58 and outputs an image signal (digital signal). The converted image signal is input to the image processing unit 68 of the processor device 16 via the connector unit 36B.

  Although not shown in the figure, various channels such as a forceps channel for inserting a tissue collection treatment tool, a channel for air supply / water supply, and the like are provided inside the operation unit and the endoscope insertion unit. ing.

  Subsequently, the processor device 16 includes a control unit 66, an image processing unit 68, and a storage unit 70. The display device 18 and the input device 20 are connected to the control unit 66. The processor device 16 controls the light amount control unit 26 of the light source device 12 based on an instruction input from the changeover switch 64 or the input device 20 of the endoscope device 14, and an image signal input from the endoscope device 14. Are processed, a display image (endoscopic image) is generated and output to the display device 20.

  The control unit 66 controls the operations of the image processing unit 68 and the light amount control unit 26 of the light source device 12 based on an instruction from the changeover switch 64 of the endoscope apparatus 14 or the input device 20, for example, an instruction such as an observation mode. To do.

  Under the control of the control unit 66, the image processing unit 68 performs a predetermined process on an image signal input from the endoscope apparatus 14 according to the image type of the white light image and the special light image based on the observation mode. Image processing is performed, and a white light image signal or a special light image signal is output.

  The white light image signal or special light image signal processed by the image processing unit 68 is sent to the control unit 66. The control unit 66 converts the white light image signal or special light image together with various information into a white light image or special light image. An image is displayed on the display device 20. Further, the white light image or the special light image is stored in the storage unit 70 including a memory or a storage device, for example, in units of one (one frame) image as necessary.

  Next, the temperature adjustment device 72 of the laser light source will be described.

  FIG. 4 is a conceptual diagram of an embodiment showing the configuration of a temperature adjustment device for a laser light source. The temperature adjusting device 72 shown in the figure is constituted by a laser fixing plate 74, a temperature adjusting element 76, a temperature measuring element 78, and a heat radiating plate 80.

  The laser fixing plate 74 is a rectangular metal plate such as aluminum on which a laser light source including white light sources 22a and 22b and narrow band light sources 24a and 24b is placed and fixed. The white light sources 22a and 22b are arranged in a horizontal row at the center of the upper surface of the laser fixing plate 74 in the drawing, and the narrow band light sources 24a and 24b are arranged in a horizontal row outside the arrangement direction of the white light sources 22a and 22b. Has been placed. That is, in the drawing, the narrow-band light source 24a, the white light sources 22a and 22b, and the narrow-band light source 24b are arranged in a horizontal row in the order.

  The temperature adjustment element 76 adjusts the laser light source to a predetermined temperature by adjusting (heating or cooling) the laser fixing plate 74 to a predetermined temperature. In the present embodiment, a Peltier element is used as the temperature adjustment element 76. The temperature control element 76 is disposed at the center of the lower surface of the laser fixing plate 74 (position corresponding to the white light sources 22a and 22b on the upper surface) so that the cooling surface is in contact with the lower surface of the laser fixing plate 74 in the drawing. A heat radiating plate 80 is attached to the heat generating surface of the temperature control element 76 so as to dissipate heat.

  The temperature measuring element 78 is disposed between the white light sources 22 a and 22 b and the temperature adjusting element 76 inside the laser fixing plate 74. The temperature measuring element 78 measures the temperature at its own position inside the laser fixing plate 74 adjusted to a predetermined temperature by the temperature adjusting element 76.

  In the temperature adjusting device 72, the temperature of the laser fixing plate 74 is adjusted by the temperature adjusting element 76, and the temperature of the laser fixing plate 74 is measured by the temperature measuring element 78. Then, based on the temperature of the laser fixing plate 74 measured by the temperature measuring element 78, the temperature of the laser fixing plate 74 is adjusted by the temperature adjusting element 76 so that the laser fixing plate 74 has a predetermined temperature. Thereby, the laser fixing plate 74 and, as will be described later, the white light sources 22a and 22b and the narrow band light sources 24a and 24b are adjusted to a predetermined temperature.

Here, the endoscope diagnostic apparatus 10 has features unique to an endoscope as shown in the following (a) to (e).
(A) The observation mode is frequently switched.
(B) The allowable range of the emission ratio for each laser light source type is narrow.
(C) The type of laser light source that emits light is different for each observation mode.
(D) The amount of light emission varies depending on the observation situation (the light amount is low for a relatively bright image and the light amount is high for a relatively dark image).
(E) In the special light observation mode, the light emission ratio differs for each laser light source type.

  However, as described above, the laser light source changes its drive current-output light quantity characteristics according to the temperature change, and further, the laser light source itself emits laser light to generate heat and change its own temperature. There is a characteristic to do. When the temperature changes, the light emission amount of the laser light source with respect to the same drive current varies, and the light emission ratio for each laser light source type also varies. Therefore, in the endoscope diagnostic apparatus 10, it is necessary to stabilize the light emission amount of each laser light source and the light emission ratio for each laser light source type by adjusting the laser light source to a predetermined temperature.

  Hereinafter, drive current-output light quantity characteristics of a laser light source having a central wavelength of 445 nm used as the white light sources 22a and 22b and a laser light source having a central wavelength of 405 nm used as the narrow-band light sources 24a and 24b will be described. .

  FIG. 6 is a graph of an embodiment showing the drive current-output light quantity characteristic of the white light source, and FIG. 7 is a graph of the embodiment showing the drive current-output light quantity characteristic of the narrow-band light source. In these graphs, the horizontal axis represents drive current (mA), and the vertical axis represents output light amount (mW). These graphs show the drive current-output light quantity characteristics at the temperatures of 25 ° C. and 35 ° C. for the white light sources 22a and 22b and the narrow-band light sources 24a and 24b.

  As shown in the graph of FIG. 6, the white light sources 22a and 22b start to emit light with a drive current of about 140 mA as a threshold, and as shown in the graph of FIG. 7, the narrow-band light sources 24a and 24b are driven. Light emission is started with a current of about 150 mA as a threshold value. Thereafter, both have a drive current-output light quantity characteristic in which the output light quantity increases in a linear function in proportion to the drive current as the drive current increases.

  For example, when the output light amount is the same 200 mW, the driving current of the white light sources 22a and 22b is about 350 mA, and the driving current of the narrow band light sources 24a and 24b is about 300 mA. If the drive voltages are the same, when the same amount of laser light is emitted, the white light sources 22a and 22b consume more power than the narrow-band light sources 24a and 24b, that is, the amount of heat generated. I understand.

  Further, when the temperature rises from 25 ° C. to 35 ° C. for both the white light sources 22a and 22b and the narrow-band light sources 24a and 24b, the threshold value of the drive current for starting light emission rises. The output light quantity decreases slightly. That is, as described above, in the white light sources 22a and 22b and the narrow-band light sources 24a and 24b, the threshold value of the drive current for starting light emission shifts and the output light amount varies according to the temperature change.

  As described above, the on / off control and the light emission control of the white light sources 22a and 22b and the narrow band light sources 24a and 24b are performed by the control of the light amount control device 26. In the white light observation mode, only the white light sources 22a and 22b are turned on, and the narrow band light sources 24a and 24b are turned off. In the special light observation mode, both the white light sources 22a and 22b and the narrow band light sources 24a and 24b are turned on, and the white light sources 22a and 22b are both narrow band light sources 24a and 24b. Is emitted at a predetermined ratio (for example, white light source 1: narrow-band light sources 4 to 5).

  That is, the white light sources 22a and 22b are always lit regardless of the observation mode, but in the white light observation mode, the white light sources 22a and 22b are driven with a relatively large current to increase the light emission amount (and the heat generation amount), and narrowband light. In the observation mode, the light emission amount is reduced by being driven with a relatively small amount of current. Note that the amount of heat generated by the laser light source is proportional to the power consumption, not the amount of light emission. As described above, the amount of light emitted from the white light sources 22a and 22b varies greatly every time the observation mode is changed.

  The narrow-band light sources 24a and 24b are turned off in the white light observation mode and turned on only in the special light observation mode. Therefore, the light emission amounts (and the heat generation amount) of the narrow-band light sources 24a and 24b greatly change in the opposite direction to the white light sources 22a and 22b every time the observation mode is changed. That is, the light emission amounts of the narrow-band light sources 24a and 24b are zero in the white light observation mode, and become a predetermined light emission amount in the special light observation mode.

  The temperature adjustment device 72 efficiently arranges the white light sources 22a and 22b by arranging the white light sources 22a and 22b having a large calorific value at the center of the laser fixing plate 74 close to the temperature control element 76 when the light quantity is the same. The configuration can be adjusted to a predetermined temperature.

  Hereinafter, the specific operation of the temperature control device 72 will be described representatively for the white light source 22a and the narrow band light source 24a, but the same applies to the white light source 22b and the narrow band light source 24b.

  In the temperature control device 72 shown in FIG. 4, the thermal resistance between the temperature adjustment element 76 and the temperature detection element 78 is R1A, the thermal resistance between the temperature detection element 78 and the white light source 22a is R1B, and the temperature adjustment element 76 The thermal resistance between the narrow-band light source 24a is R2A, and the thermal resistance between the narrow-band light source 24a and the white light source 22a is R2B.

  In the temperature control device 72, the white light source 22a is set so that the ratio R1B / R1A of the thermal resistances R1A and R1B and the ratio R2B / R2A of the thermal resistances R2A and R2B are approximately equal (R1B / R1A≈R2B / R2A). And the narrow-band light source 24a are determined, and both are fixedly arranged at the distance. In order to finely adjust the thermal resistance ratio R1B / R1A and the thermal resistance ratio R2B / R2A to be exactly equal, the laser fixing plate 74 is formed in a predetermined shape. In the case of the present embodiment, as shown in FIGS. 5A and 5B, a groove portion 82 or a mountain portion 84 is formed in the region of the laser fixing plate 74 between the white light source 22a and the narrow-band light source 24a. Is formed.

  That is, by forming the groove 82 in the region between the white light source 22a and the narrow-band light source 24a of the laser fixing plate 74, the thermal resistance R2B can be increased, and conversely in the region between the two. By forming the peak portion 84, the thermal resistance R2B can be lowered. Thus, by adjusting the thermal resistance R2B, the thermal resistance ratio R2B / R2A can be adjusted, thereby adjusting the thermal resistance ratio R1B / R1A and the thermal resistance ratio R2B / R2A to be equal. be able to.

  The temperature of the white light source 22a is adjusted to a predetermined temperature determined by the temperature at the position of the temperature measuring element 78 and the thermal resistance ratio R1B / R1A.

  Regarding the thermal resistance ratio R1B / R1A, the white light source 22a is a heat source, the temperature adjustment element 76 is a cold source, and a temperature detection element 78 is arranged between the two. Similarly, with respect to the thermal resistance ratio R2B / R2A, the white light source 22a is a heat source, the temperature control element 76 is a cold source, and the narrow-band light source 24a is disposed at a position between them. Accordingly, if the thermal resistance ratio R1B / R1A is equal to the thermal resistance ratio R2B / R2A, the temperature of the narrow-band light source 24a is adjusted to a temperature proportional to the temperature at the position of the temperature measuring element 78.

  That is, as described above, the thermal resistance ratio R2B / R2A and the thermal resistance ratio R1B / R1A are set equal to each other, and the temperature at the position of the temperature measuring element 78 is adjusted to a predetermined temperature by the temperature adjustment element 76. Accordingly, the white light source 22a is inevitably adjusted to the temperature at the position of the temperature measuring element 78 and a predetermined temperature determined by the thermal resistance ratio R1B / R1A, and the narrow band light source 24a is also used as the temperature measuring element. It can be adjusted to a predetermined temperature proportional to the temperature at the 78 position.

  Even when the observation mode is frequently switched and the plurality of laser light sources are frequently switched on and off by adjusting each laser light source to a predetermined temperature by the temperature adjusting device 72, the laser light sources are driven. It is possible to prevent the current-output light quantity characteristic from fluctuating, and it is possible to output laser light having a predetermined light emission amount from each laser light source. Thereby, it is possible to prevent variations in the amount of illumination light emitted from the light source device 12, and consequently the endoscope device 14, and to improve the image quality of the captured endoscope image.

  Further, the temperature adjusting device 72 only needs to have one laser fixing plate 74, temperature adjusting element 76, and heat radiating plate 80 for each of the plurality of laser light sources. Cost can be reduced. In addition, each laser light source can be adjusted to a predetermined temperature simply by adjusting the temperature at the position of the temperature measuring element 78 to a predetermined temperature, so that there is an advantage that control is easy.

  It is desirable to provide two or more white light sources and one or more narrow-band light sources. For example, when there are two white light sources and one narrow band light source, the excitation light emitted from one white light source and the narrow band light emitted from the narrow band light source are combined and the other white light is combined. The excitation light emitted from the light source may be output as it is, or all of the excitation light and the narrowband light may be output as they are without being combined. This is the same regardless of the number of white light sources and narrow-band light sources.

Next, the operation of the endoscope diagnosis apparatus 10 will be described.
First, the operation in the white light observation mode will be described.

  An instruction such as an observation mode is input to the control unit 66 of the processor device 16 from the changeover switch 64 of the endoscope device 14 or the input device 20. Then, the control unit 66 controls the image processing unit 68 and the light amount control unit 26 of the light source device 12 according to the observation mode.

  In the white light observation mode, the light source device 12 emits two lines of excitation light for white light observation.

  In the endoscope apparatus 14, two types of excitation light for white light observation emitted from the light source apparatus 12 are guided to the phosphors 52a and 52b of the endoscope distal end portion 42 by optical fibers 54a and 54b, respectively. The As a result, white light is emitted from the phosphors 52a and 52b, and is irradiated onto the observation region of the subject from the irradiation windows 46a and 46b via the lenses 50a and 50b, respectively. Then, the reflected light from the observation region is collected by the objective lens unit 56 and is photoelectrically converted by the image sensor 58 to output a white light image signal (analog signal).

  The image signal (analog signal) of the white light image is converted into an image signal (digital signal) by the A / D converter 62, and predetermined image processing suitable for the white light image is performed by the image processing unit 68 according to the observation mode. And a white light image signal is output. Then, the control unit 66 generates a white light image from the white light image signal according to the image display mode, and displays the white light image on the display device 18.

  When the observation is completed, the endoscope insertion portion 32 is taken out from the body cavity of the subject, and the power of each device is turned off.

  Next, the operation in the special light observation mode will be described.

  In the special light observation mode, the light source device 12 emits two systems of combined light of excitation light for white light observation and narrowband light for special light observation.

  In the endoscope device 14, the two systems of combined light emitted from the light source device 12 are guided to the phosphors 52 a and 52 b of the endoscope distal end portion 42 by optical fibers 54 a and 54 b, respectively. As a result, white light is emitted from the phosphors 52a and 52b and narrow band light for special light observation is emitted from the irradiation windows 46a and 46b through the lenses 50a and 50b to the observation region of the subject, respectively. Irradiated. Then, the reflected light from the observation region is collected by the objective lens unit 56, and photoelectrically converted by the image sensor 58, and an image signal (analog signal) of the special light image is output.

  The image signal (analog signal) of the special light image is converted into an image signal (digital signal) by the A / D converter 62, and predetermined image processing suitable for the special light image is performed by the image processing unit 68 according to the observation mode. Then, a special light image signal is output. Then, the control unit 66 generates a special light image from the special light image signal according to the image display mode, and displays the special light image on the display device 18.

  When the observation is completed, the endoscope insertion portion 32 is taken out from the body cavity of the subject, and the power of each device is turned off.

  In the white light image, a blood vessel image of a relatively deep mucosa can be obtained and the brightness of the entire image can be easily increased. On the other hand, in the narrow-band light image, fine capillaries on the mucous membrane surface layer can be seen clearly. Therefore, the composite image (special light image) of the white light image and the narrow-band light image captured in the special light observation mode can secure sufficient luminance in the entire image, and the microvessels on the surface of the mucous membrane of the living tissue There is an advantage that it is easy to diagnose the affected area.

The present invention is basically as described above.
Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and it is needless to say that various improvements and modifications may be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 Endoscopic diagnosis apparatus 12 Light source apparatus 14 Endoscope apparatus 16 Processor apparatus 18 Display apparatus 20 Input apparatus 22a, 22b White light source 24a, 24b Narrow band light source 26 Light quantity control part 28a, 28b Multiplexer 30a, 30b, 54a, 54b Optical fiber 32 Endoscope insertion part 34 Operation part 36A, 36B Connector part 38 Soft part 40 Bending part 42 Tip part 44 Angle knob 46a, 46b, 114 Irradiation window 48 Observation window 50a, 50b Lens 52a, 52b Phosphor 56 Objective Lens Unit 58 Image Sensor 60 Scope Cable 62 A / D Converter 64 Changeover Switch 66 Control Unit 68 Image Processing Unit 70 Storage Unit 72, 94 Temperature Control Device 74, 88a, 88b, 88c, 88d Laser Fixing Plate 76, 90a , 90b, 90c, 90d Temperature control element 8 thermometric element 80,92a, 92b, 92c, 92d radiating plate 82 grooves 84 crest 94 laser light source

Claims (10)

There are two or more first laser light sources and one or more second laser light sources whose light amounts are controlled separately from the first laser light sources, and the light amounts of the first and second laser light sources are controlled at an arbitrary ratio. A temperature control device used in the light source device,
A laser fixing plate in which the first laser light sources are arranged in a row at the center of one surface, and the second laser light sources are arranged in a row outside the arrangement direction of the first laser light sources;
A temperature control element disposed at the center of the other surface of the laser fixing plate;
A temperature sensing element disposed between the first and second laser light sources and the temperature control element;
The ratio of the thermal resistance between the temperature control element and the temperature detection element, the thermal resistance between the temperature detection element and the first laser light source, and the temperature control element and the second laser light source A predetermined fixed interval between the first laser light source and the second laser light source so that a ratio of a thermal resistance between the first laser light source and a thermal resistance between the second laser light source and the first laser light source is equal. And the laser fixing plate is formed in a predetermined shape.   The temperature control device according to claim 1, wherein the first laser light source has a larger calorific value than the second laser light source in the case of the same light amount.   3. The temperature adjusting device according to claim 1, wherein the first laser light source has a light emission ratio smaller than that of the second laser light source when both the first and second laser light sources are turned on.   The temperature control according to claim 1, wherein the first laser light source emits laser light having a central wavelength of 445 nm, and the second laser light source emits laser light having a central wavelength of 405 nm. apparatus.   The temperature control device according to claim 1, wherein the temperature adjustment element is a Peltier element. There are two or more first laser light sources and one or more second laser light sources whose light amounts are controlled separately from the first laser light sources, and the light amounts of the first and second laser light sources are controlled at an arbitrary ratio. A temperature control method applied to the light source device,
The first laser light sources are arranged in a row at the center of one surface of the laser fixing plate, and the second laser light sources are arranged in a row outside the arrangement direction of the first laser light sources,
A temperature control element is arranged at the center of the other surface of the laser fixing plate,
A temperature measuring element is disposed between the first laser light source and the temperature control element;
The ratio of the thermal resistance between the temperature control element and the temperature detection element, the thermal resistance between the temperature detection element and the first laser light source, and the temperature control element and the second laser light source A predetermined fixed interval between the first laser light source and the second laser light source so that a ratio between a thermal resistance between the second laser light source and the first laser light source is equal. And the laser fixing plate is formed in a predetermined shape.   The temperature adjustment method according to claim 6, wherein the first laser light source generates a larger amount of heat than the second laser light source when the light amount is the same.   The temperature control method according to claim 6 or 7, wherein the first laser light source has a light emission ratio smaller than that of the second laser light source when both the first and second laser light sources are turned on. A light source device for emitting illumination light used in an endoscopic diagnostic device,
Two or more first laser light sources;
One or more second laser light sources whose light amounts are controlled separately from the first laser light source;
The temperature control device according to any one of claims 1 to 5,
A light source device comprising: a light amount control unit that performs on / off control and light amount control of the first and second laser light sources. The light source device according to claim 9;
An endoscope apparatus that captures an endoscopic image of an observation region of a subject using illumination light emitted from the light source device;
A processor device for performing image processing on an endoscopic image captured by the endoscopic device;
An endoscope diagnosis apparatus comprising: a display device that displays an endoscope image subjected to image processing by the processor device.

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