WO2019087640A1

WO2019087640A1 - Light source device

Info

Publication number: WO2019087640A1
Application number: PCT/JP2018/036427
Authority: WO
Inventors: 修平畑中; 小谷　理
Original assignee: オリンパス株式会社
Priority date: 2017-11-01
Filing date: 2018-09-28
Publication date: 2019-05-09

Abstract

A light source device 4 is equipped with: a light source unit 43 for generating light of at least a portion of the desired wavelength bands; a wavelength shift detection filter 46 which is disposed on a predetermined optical path of the light generated by the light source unit 43 and changes, according to the wavelength of the incident light, the state of light to be output; and an optical sensor 47 for receiving the light output from the wavelength shift detection filter 46, converting the received light into a voltage, and detecting changes in the value of the voltage.

Description

Light source device

The present invention relates to a light source device, and more particularly, to a light source device including a light source unit for generating light in at least a part of a desired wavelength band.

An endoscope including an imaging element for imaging a subject inside a subject, an image processing apparatus called a so-called video processor for generating an observation image of the subject captured by the endoscope, and a subject from the endoscope An endoscope system including a light source device and the like for generating and emitting illumination light to be irradiated to a specimen is widely used in the medical field, the industrial field, and the like.

In the light source device in such an endoscope system, recently, a light source device provided with a solid light source such as a light emitting diode (LED) or a semiconductor laser (laser diode LD) has been developed.

As a solid-state light source as described above, for example, Japanese Patent Laid-Open No. 2015-4902 shows a light source device which uses monochromatic solid-state light source by LED and outputs stable color light regardless of temperature change. There is.

Further, in JP-A-2012-47951 and JP-A-2015-72387, for example, a solid light source by a semiconductor laser for emitting excitation light, and a phosphor for converting the excitation light into fluorescence A light source device is disclosed.

Here, it is known that the variation of the wavelength and the amplitude of the light emission of the semiconductor laser light source is relatively small, and also the spread of the wavelength at which the relative light output with respect to the peak wavelength is 50% is small. Furthermore, since semiconductor lasers enable irradiation of so-called "coherent light", in which not only the wavelength but also the phase are aligned, in recent years, a light source device for endoscopes that requires high-precision wavelength control using such properties. Is also adopted in

However, in the light source device using a solid-state light source such as a semiconductor laser as described above, the wavelength band of light generated from the solid-state light source shifts and deviates from a desired wavelength band due to the influence of fluctuations in drive current or temperature change. It is known that there is a risk.

In particular, in the light source device for an endoscope using a semiconductor laser, for example, a shift of about 5 nm with a very small wavelength occurs with respect to light near the center frequency 600 nm. Also, there is a possibility that the disadvantage that the desired image can not be obtained in the endoscope system may occur. For example, it is known that when the light wavelength of the light source is shifted to the short wavelength side in the mode in which deep blood vessels and bleeding points can be observed, the visibility of deep blood vessels and bleeding points may be reduced.

As a light source device for reducing the influence of this wavelength shift, conventionally, in a light source device in which a phosphor is irradiated with laser light as an excitation light source and fluorescence emitted from the phosphor is irradiated onto an observation target as illumination light. It is done.

That is, the light source device detects the fluorescence generated from the phosphor excited by the excitation light generated from the light source with the light sensor, and when the output of the light sensor decreases, the wavelength of the light generated from the light source is It detects that it has shifted. Then, by detecting this wavelength shift, it is detected that the wavelength band of the excitation light has deviated from the desired wavelength band.

However, this light source device detects the wavelength shift of the excitation light which is the light source by detecting the fluorescence generated from the fluorescent substance with the light sensor, and the light source device does not apply to the light source device not using the fluorescent substance could not.

The present invention has been made in view of the above circumstances, and a light source that can detect that the wavelength of light emitted from the light source deviates from a desired wavelength band even if it is a light source device that does not use a phosphor It aims at providing an apparatus.

A light source device according to an aspect of the present invention includes a light source unit for generating light in at least a part of a desired wavelength band and a predetermined light path of light generated by the light source unit. A light control unit that changes the state of light to be output according to the wavelength of the emitted light, and the light output from the light control unit is received, and the received light is converted into a voltage and the change of the value of the voltage And a detection unit that detects the

FIG. 1 is a diagram showing a configuration of an endoscope system including a light source device according to a first embodiment of the present invention. FIG. 2 is a view showing how light in a desired wavelength band emitted from the light source is shifted in the light source device of the first embodiment. FIG. 3 shows the wavelength transition of the first state before wavelength shift and the second state after wavelength shift (after shift to the short wavelength side) and the wavelength band in the light source device of the first embodiment. It is the figure which showed the relationship between the stop zone (normality) and the transmission zone (shift) in a restriction | limiting part. FIG. 4 is a view of wavelength transition of the first state before wavelength shift and the third state after wavelength shift (after shift to the long wavelength side) in the light source device according to the second embodiment of the present invention; It is the figure which showed the relationship of the stop zone (normal) and the transmission zone (shift) in a wavelength zone limiting part. FIG. 5 shows the transition of wavelength between the first state before wavelength shift and the second state after wavelength shift (after shift to the short wavelength side) in the light source device according to the third embodiment of the present invention It is the figure which showed the relationship between the permeation | transmission band (normality) and the stop band (shift) in a wavelength band limitation part. FIG. 6 shows the transition of wavelength between the first state before wavelength shift and the third state after wavelength shift (after shift to the long wavelength side) in the light source device according to the fourth embodiment of the present invention It is the figure which showed the relationship between the permeation | transmission band (normality) and the stop band (shift) in a wavelength band limitation part. FIG. 7 is a view showing a configuration of an endoscope system including the light source device of the fifth embodiment of the present invention. FIG. 8 is a view showing a state in which light of a desired wavelength band emitted from the light source is shifted in the light source device of the fifth embodiment. FIG. 9 shows the wavelength transition between the first state before wavelength shift and the second state after wavelength shift (after shift to the short wavelength side) and the wavelength band in the light source device of the fifth embodiment. It is the figure which showed the relationship of the transmission zone (normality) and the reflection zone (shift) in a restriction | limiting part.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment
FIG. 1 is a view showing a configuration of an endoscope system including a light source device according to a first embodiment of the present invention, and FIG. 2 is a view showing a desired light source irradiated from a light source in the light source device according to the first embodiment. It is the figure which showed a mode when the light of the wavelength zone | band shifted.

As shown in FIG. 1, an endoscope system 1 having a light source device according to the first embodiment includes an endoscope 2 for observing a subject and outputting an imaging signal, and the endoscope 2 connected to the endoscope 2. There is a video processor 3 that receives an imaging signal and performs predetermined image processing, a light source device 4 that supplies illumination light for illuminating a subject, and a monitor device 5 that displays an observation image according to the imaging signal. doing.

The endoscope 2 includes an objective optical system 21 disposed at the distal end of the insertion portion, the objective optical system 21 including a lens for receiving an object image, and an imaging element 22 disposed on the imaging surface of the objective optical system 21. And an illumination unit capable of applying predetermined illumination light to a subject.

The imaging element 22 is formed of, for example, a CMOS image sensor, forms an optical image from a subject on the imaging surface, photoelectrically converts light incident on each pixel in a photoelectric conversion unit, and outputs a predetermined imaging signal. It is supposed to be.

The illumination unit 23 is disposed at the tip of the light guide 24 extending from the light source device 4 to the inside of the endoscope 2 and emits illumination light generated by the light source device 4.

In the present embodiment, the video processor 3 receives an image signal from the endoscope 2 and a processor control unit 31 that controls various circuits in the endoscope 2 and the light source device 4 connected in addition to the video processor 3. An image processing unit 32 that performs predetermined image processing; and a video output unit 33 that receives an image signal processed by the image processing unit 32 and generates a video signal to be displayed on the monitor device 5.

<Configuration of light source device>
In the present embodiment, the light source device 4 includes a light source 43 that generates (emits) laser light with a predetermined center wavelength, and further, a drive unit 42 that drives the light source 43 and a light source that performs light emission control of the light source 43 The apparatus control unit 41 is mainly provided.

In the present embodiment, the light source 43 is a solid-state light source configured of three semiconductor lasers (laser diode LD; laser diode) such as a red semiconductor laser, a green semiconductor laser, and a blue semiconductor laser. Under the control of the control unit 41, the drive unit 42 is driven to emit red, green and blue laser beams, respectively.

In FIGS. 1 and 2, among the three-color semiconductor lasers in the light source 43, the configuration relating to the semiconductor laser for one color is shown as a representative. That is, the red semiconductor laser, the green semiconductor laser, and the blue semiconductor laser all have the same configuration, and the emission light path, the half mirror 44 described later, the filter 46 for wavelength shift detection, and the optical sensor 47 Each has a similar configuration.

As described above, the light source 43 serves as a light source unit for generating (emitting) light of at least a part of the desired wavelength band.

In the present embodiment, the half mirror 44 is disposed on the optical path OP1 of the laser light emitted from the light source 43 (red semiconductor laser, green semiconductor laser and blue semiconductor laser). As described above, the half mirror 44 is disposed on the optical path OP1 of each of the red, green and blue semiconductor lasers, but in FIG. 1 and FIG. Only for illustration.

The half mirror 44 is a light control unit that changes the state of light to be output according to the wavelength of the incident light (R light, G light, B light), and the light emitted from the light source 43 (R It has a function as an optical path separation unit that separates light, G light, and B light) into transmitted light and reflected light, respectively.

A condenser lens 45 is disposed on the optical path of the transmitted light (R light, G light, B light) transmitted through the half mirror 44 in each optical path system. That is, all the light (R light, G light, B light) transmitted through the half mirror 44 is condensed by the condenser lens 45, and thereafter, from the illumination unit 23 of the endoscope 2 via the light guide 24 It is supposed to be irradiated.

On the other hand, the reflected light from the half mirror 44 is received on the optical path OP2 of each reflected light (R light, G light, B light) reflected by the half mirror 44, and the received light is converted into a voltage. An optical sensor (detection unit) 47 that detects a change in the value of the voltage is disposed.

In addition, on the optical path OP2 of the reflected light (R light, G light, B light), a wavelength shift detection filter 46 for entering the reflected light is provided on the light entrance surface of each light sensor 47. It is done.

<Wavelength shift detection filter 46 as light control unit>
The respective wavelength shift detection filters 46 shift to a short wavelength side by a certain wavelength from the light of the “desired wavelength band” and when light of the “desired wavelength band” is input as the reflected light. It has a function as a light control unit that makes the state of light to be output different depending on when shift light is input.

Further, the wavelength shift detection filter 46 in the first embodiment serves as a wavelength band limiting unit that limits the transmission of the light of the “desired wavelength band”.

With regard to semiconductor lasers, it is known that the wavelength band of light emitted from the semiconductor laser light source may be shifted and deviate from the desired wavelength band due to the influence of fluctuations in drive current or changes in ambient temperature. ing.

FIG. 3 shows the wavelength transition of the first state before wavelength shift and the second state after wavelength shift (after shift to the short wavelength side) and the wavelength band in the light source device of the first embodiment. It is the figure which showed the relationship of the stop zone (normality) and the transmission zone (shift) in a restriction part (filter 46 for wavelength shift detection).

As shown in FIG. 3, in the first embodiment, the wavelength shift detection filter 46 blocks at least the transmission of light of a desired wavelength band emitted from the light source 43, and A “transmission band” is formed to transmit light in a band shorter than the desired wavelength band ”.

In the first embodiment, the “cut-off band” in the filter for wavelength shift detection 46 is a first one in which the laser light (one of R light, G light, and B light as described above) emitted from the light source 43 is normal. This band corresponds to the state (indicated before wavelength shift in FIG. 3).

In other words, in the first embodiment, the filter 46 for wavelength shift detection is a band corresponding to the case where the normal laser light of the "desired wavelength band" is emitted from the light source 43, this "desired wavelength band" And a "blocking band" that blocks the transmission of light.

When normal laser light in the “desired wavelength band” is emitted from the light source 43, the reflected light OP2 from the half mirror 44 is incident on the wavelength shift detection filter 46 as shown in FIG. The transmission of light of this reflected light OP2 is cut off by the "cut-off band".

And the laser beam (normal laser beam) radiate | emitted from the light source 43 will not inject into the optical sensor 47 corresponding to the said filter 46 for wavelength shift detection.

On the other hand, in the “transmission band” of the filter for detecting wavelength shift 46 in the first embodiment, the laser light of at least one color of the laser light (R light, G light, B light) emitted from the light source 43 has a short wavelength This is a band corresponding to the case where the second state shifted to the side (described as after the wavelength shift in FIG. 3) is reached.

In other words, in the first embodiment, the filter for wavelength shift detection 46 is a band corresponding to the case where the laser light of the “desired wavelength band” is emitted from the light source 43 to the short wavelength side. It has a "transmission band" that transmits light in the "wavelength band shifted to the short wavelength side".

When the laser light in the “desired wavelength band” is emitted from the light source 43 while being shifted to the short wavelength side, the reflected light OP2 from the half mirror 44 is transmitted to the filter for wavelength shift detection 46 as shown in FIG. After being incident, the light is transmitted by the “transmission band” and is output as the reflected light OP3.

Then, the laser beam (shifted laser beam) emitted from the light source 43 and reflected from the half mirror 44 is incident on the optical sensor 47 corresponding to the wavelength shift detection filter 46.

At this time, the light sensor 47 detects that the laser light emitted from the light source 43 has shifted to the short wavelength side by receiving the shifted laser light.

More specifically, it is assumed that the red laser light of the center wavelength (for example, 600 nm) emitted from the light source 43 is shifted to the short wavelength side by a predetermined wavelength (for example, about 5 nm). . At this time, the wavelength shift detection filter 46 transmits the shifted reflected light OP2 reflected by the half mirror 44, and outputs it to the optical sensor 47 as a reflected light OP3.

The light sensor 47 receives the reflected light OP3 which is the shifted laser light, converts the received light OP3 into a voltage, and detects a change in the value of the voltage. Thus, the light sensor 47 detects that the red laser light emitted from the light source 43 is out of the “desired wavelength band” and shifted to the short wavelength side.

In addition, the specific example mentioned above gave the example which the red laser beam of center wavelength (for example, 600 [nm]) shifted to the short wavelength side. However, the light source device of the first embodiment corresponds to the green semiconductor laser and the blue semiconductor laser even when the laser light of other colors (green laser light and blue laser light) is shifted to the short wavelength side. The optical sensor 47 can detect the wavelength shift.

As described above, according to the light source device of the first embodiment, the wavelength of the light emitted from the light source is shifted from the desired wavelength band to the short wavelength side even in the light source device which does not use the phosphor. Can be detected.

Second Embodiment
Next, a second embodiment of the present invention will be described.

The light source device of the second embodiment is the same as the first embodiment in the main configuration, and only the differences from the first embodiment will be described here, and the description of the common parts will be omitted.

While the first embodiment is characterized by “detecting that the wavelength of light emitted from the light source is shifted from the desired wavelength band to the short wavelength side”, the second embodiment is an embodiment of the present invention. And “detecting that the wavelength of the light emitted from the light source is shifted from the desired wavelength band to the long wavelength side”.

FIG. 4 is a view of wavelength transition of the first state before wavelength shift and the third state after wavelength shift (after shift to the long wavelength side) in the light source device according to the second embodiment of the present invention; It is the figure which showed the relationship of the stop zone (normal) and the transmission zone (shift) in a wavelength zone limiting part.

<Wavelength shift detection filter 46 of the second embodiment>
In the second embodiment, the wavelength shift detection filter 46, which is a wavelength band limiting unit, receives a light of a "desired wavelength band" as the reflected light, and the light from the "desired wavelength band" is constant. It has a function as a light control unit that differs in the state of the light to be output when the shifted light shifted to the long wavelength side by the wavelength is input.

Also in the second embodiment, the wavelength shift detection filter 46 serves as a wavelength band limiting unit that limits the transmission of the light of the “desired wavelength band”.

As shown in FIG. 4, in the second embodiment, the wavelength shift detection filter 46 blocks at least the transmission of light of a desired wavelength band emitted from the light source 43, and A “transmission band” is formed to transmit light in a band on the longer wavelength side than the desired wavelength band ”.

In the second embodiment, the “cut-off band” in the filter for wavelength shift detection 46 is a first one in which the laser light (one of R light, G light, and B light as described above) emitted from the light source 43 is normal. This band corresponds to the state (indicated before wavelength shift in FIG. 4).

In other words, also in the second embodiment, the filter 46 for wavelength shift detection is a band corresponding to the case where the normal laser light of the “desired wavelength band” is emitted from the light source 43. It has a "blocking band" that blocks the transmission of light in the "wavelength band".

Also in the second embodiment, when the normal laser light of the “desired wavelength band” is emitted from the light source 43, the filter for wavelength shift detection 46 is shown in FIG. 1 described in the first embodiment. As described above, although the reflected light OP2 from the half mirror 44 is incident, the transmission of the reflected light OP2 is blocked by the "cut-off band".

Also in the second embodiment, the laser beam (normal laser beam) emitted from the light source 43 does not enter the light sensor 47 corresponding to the wavelength shift detection filter 46.

On the other hand, in the “transmission band” of the filter for detecting wavelength shift 46 in the second embodiment, the laser light of at least one color of the laser light (R light, G light, B light) emitted from the light source 43 has a long wavelength This is a band corresponding to the case where the third state shifted to the side (indicated as after the wavelength shift in FIG. 4) is reached.

In other words, in the second embodiment, the filter 46 for wavelength shift detection is a band corresponding to the case where the laser light of the “desired wavelength band” is emitted from the light source 43 to the long wavelength side. It has a "transmission band" that transmits light in the "wavelength band shifted to the long wavelength side".

When the laser light in the “desired wavelength band” is emitted from the light source 43 while shifting to the long wavelength side, the wavelength shift detection filter 46 is a half as shown in FIG. 2 described in the first embodiment. After the reflected light OP2 from the mirror 44 is incident, it is transmitted by the "transmission band" and is output as the reflected light OP3.

Also in the second embodiment, the laser beam (shifted laser beam) emitted from the light source 43 and reflected from the half mirror 44 enters the optical sensor 47 corresponding to the filter for wavelength shift detection 46. It will be done.

At this time, the light sensor 47 detects that the laser light emitted from the light source 43 has shifted to the long wavelength side by receiving the shifted laser light.

More specifically, in the second embodiment, the red laser light of the center wavelength (e.g., 600 [nm]) emitted from the light source 43 has a predetermined wavelength (e.g., 5 [nm]) on the long wavelength side. Degree) shift. At this time, the wavelength shift detection filter 46 transmits the shifted reflected light OP2 reflected by the half mirror 44, and outputs it to the optical sensor 47 as a reflected light OP3.

The light sensor 47 receives the reflected light OP3 which is the shifted laser light, converts the received light OP3 into a voltage, and detects a change in the value of the voltage. Thus, the light sensor 47 detects that the red laser light emitted from the light source 43 is out of the “desired wavelength band” and shifted to the long wavelength side.

In addition, the specific example mentioned above gave the example which the red laser beam of center wavelength (for example, 600 [nm]) shifted to the long wavelength side. However, in the light source device of the second embodiment, even when the laser light of other colors (green laser light and blue laser light) is shifted to the long wavelength side, it corresponds to the green semiconductor laser and the blue semiconductor laser, respectively. In the optical sensor 47, the wavelength shift can be detected.

As described above, according to the light source device of the second embodiment, the wavelength of the light emitted from the light source is shifted from the desired wavelength band to the long wavelength side even in the light source device which does not use the phosphor. Can be detected.

Third Embodiment
Next, a third embodiment of the present invention will be described.

The light source device of the third embodiment has the main configuration similar to that of the first embodiment, and only the differences from the first embodiment will be described here, and the description of the common parts will be omitted.

Similar to the first embodiment, the third embodiment “detects that the wavelength of the light emitted from the light source has shifted from the desired wavelength band to the short wavelength side”, but the third embodiment is the third embodiment. This embodiment is characterized in that the relationship between the “stopband” and the “transmission band” in the filter for wavelength shift detection 46 is different from the first embodiment.

FIG. 5 shows the transition of wavelength between the first state before wavelength shift and the second state after wavelength shift (after shift to the short wavelength side) in the light source device according to the third embodiment of the present invention It is the figure which showed the relationship between the permeation | transmission band (normality) and the stop band (shift) in a wavelength band limitation part.

<Wavelength shift detection filter 46 in the third embodiment>
In the light source device according to the third embodiment, the wavelength shift detection filter 46 receives light of a “desired wavelength band” as the reflected light, and a certain wavelength of light from the light of the “desired wavelength band”. It has a function as a light control unit that makes the state of the light to be output different depending on when the shifted light shifted to the short wavelength side is input.

As shown in FIG. 5, in the third embodiment, the wavelength shift detection filter 46 transmits at least a “desired wavelength band” light emitted from the light source 43 and a “transmission band”; A "blocking band" for blocking transmission of light in a band shorter than the wavelength band "is formed.

In the third embodiment, the “transmission band” in the filter for wavelength shift detection 46 is a first one in which the laser light (one of R light, G light, and B light as described above) emitted from the light source 43 is normal. This band corresponds to the state (indicated before wavelength shift in FIG. 5).

In other words, in the third embodiment, the filter 46 for wavelength shift detection is a band corresponding to the case where a normal laser beam of the "desired wavelength band" is emitted from the light source 43. The "transmission band" transmits light of

When normal laser light in the “desired wavelength band” is emitted from the light source 43, the filter for detecting wavelength shift 46 in the third embodiment is as shown in FIG. 2 described in the first embodiment. After the reflected light OP2 from the half mirror 44 is incident, it is transmitted by the "transmission band" and is output as the reflected light OP3.

Then, the laser beam (normal laser beam) emitted from the light source 43 and reflected from the half mirror 44 is incident on the optical sensor 47 corresponding to the wavelength shift detection filter 46.

At this time, the light sensor 47 detects that the laser light emitted from the light source 43 is in a normal state by receiving the normal laser light.

On the other hand, in the third embodiment, the “cut-off band” in the filter for wavelength shift detection 46 has a short wavelength of the laser light of at least one color of the laser light (R light, G light, B light) emitted from the light source 43 This is a band corresponding to the case where the second state shifted to the side (described as after the wavelength shift in FIG. 5) is reached.

In other words, in the third embodiment, the filter 46 for wavelength shift detection is a band corresponding to the case where the laser light of the “desired wavelength band” is emitted from the light source 43 to the short wavelength side. It has a "blocking band" for blocking light of "wavelength band shifted to the short wavelength side".

When the laser light of the “desired wavelength band” is emitted from the light source 43 while being shifted to the short wavelength side, the filter for wavelength shift detection 46 in the third embodiment is the diagram described in the first embodiment. As shown in FIG. 1, the reflected light OP2 from the half mirror 44 is incident, but the transmission of the reflected light OP2 is blocked by the "blocking band".

Then, the laser beam (shifted laser beam) emitted from the light source 43 and reflected from the half mirror 44 does not enter the optical sensor 47 corresponding to the wavelength shift detection filter 46.

At this time, the light sensor 47 detects that the laser light emitted from the light source 43 has shifted to the short wavelength side by not receiving the shifted laser light.

More specifically, when the red laser light of the center wavelength (for example, 600 [nm]) emitted from the light source 43 is normally output, the filter 46 for wavelength shift detection in the third embodiment is a half. The shifted reflected light OP2 reflected by the mirror 44 is transmitted, and is output to the light sensor 47 as a reflected light OP3 (see FIG. 2).

The optical sensor 47 receives the reflected light OP3 which is the laser light in the normal state, converts the received light OP3 into a voltage and measures the voltage value, so that the red laser light emitted from the light source 43 It is recognized that the normal state is within the desired wavelength band.

On the other hand, it is assumed that the red laser light of the central wavelength (e.g., 600 [nm]) emitted from the light source 43 is shifted to the short wavelength side by a predetermined wavelength (e.g., about 5 [nm]). At this time, the wavelength shift detection filter 46 blocks the shifted reflected light OP2 reflected by the half mirror 44 (see FIG. 1).

In the optical sensor 47, since the incoming light of the reflected light OP3 (which is the laser light in the normal state) which has been received until then is interrupted, the value of the voltage related to the reflected light also changes. The light sensor 47 detects the change in the voltage value to detect that the red laser light emitted from the light source 43 is out of the “desired wavelength band” and shifted to the short wavelength side.

In the above-mentioned specific example, the red laser light of the central wavelength (for example, 600 [nm]) is shifted to the short wavelength side. However, the light source device of the third embodiment is the first embodiment. As in the embodiment, even when laser light of another color (green laser light or blue laser light) is shifted to the short wavelength side, the wavelength shift is performed in the light sensor 47 corresponding to the green semiconductor laser and the blue semiconductor laser, respectively. Can be detected.

As described above, according to the light source device of the third embodiment, the wavelength of the light emitted from the light source is shifted from the desired wavelength band to the short wavelength side even in the light source device which does not use the phosphor. Can be detected.

Fourth Embodiment
Next, a fourth embodiment of the present invention will be described.

The light source device of the fourth embodiment is the same as the first and second embodiments in the main configuration, and only the difference from the first embodiment is described here, and the description of the common parts is omitted. Do.

Similar to the second embodiment, the fourth embodiment “detects that the wavelength of the light emitted from the light source has shifted from the desired wavelength band to the long wavelength side”, but the fourth embodiment is the fourth embodiment. This embodiment is characterized in that the relationship between the "stopband" and the "transmission band" in the filter for wavelength shift detection 46 is different from the first and second embodiments.

FIG. 6 shows the transition of wavelength between the first state before wavelength shift and the third state after wavelength shift (after shift to the long wavelength side) in the light source device according to the fourth embodiment of the present invention It is the figure which showed the relationship between the permeation | transmission band (normality) and the stop band (shift) in a wavelength band limitation part.

<Wavelength shift detection filter 46 in the fourth embodiment>
In the light source device according to the fourth embodiment, the wavelength shift detection filter 46 receives a light of a "desired wavelength band" as the reflected light, and a predetermined wavelength of light from the light of the "desired wavelength band". It has a function as a light control unit that makes the state of the light to be output different depending on when the shifted light shifted to the long wavelength side is input.

As shown in FIG. 6, in the fourth embodiment, the wavelength shift detection filter 46 transmits at least a “desired wavelength band” light emitted from the light source 43 and a “transmission band”; A "blocking band" for blocking transmission of light in a band on the longer wavelength side than the "wavelength band" is formed.

In the fourth embodiment, the “transmission band” in the filter for wavelength shift detection 46 is a first one in which the laser light (one of R light, G light, and B light as described above) emitted from the light source 43 is normal. This band corresponds to the state (indicated before wavelength shift in FIG. 6).

In other words, in the fourth embodiment, the filter 46 for wavelength shift detection is a band corresponding to the case where a normal laser beam of the "desired wavelength band" is emitted from the light source 43. The "transmission band" transmits light of

When the normal laser light in the “desired wavelength band” is emitted from the light source 43, the filter for detecting wavelength shift 46 in the fourth embodiment is as shown in FIG. 2 described in the first embodiment. After the reflected light OP2 from the half mirror 44 is incident, it is transmitted by the "transmission band" and is output as the reflected light OP3.

On the other hand, in the fourth embodiment, the “cut-off band” in the filter for wavelength shift detection 46 is a long wavelength of the laser light of at least one color of the laser light (R light, G light, B light) emitted from the light source 43 This is a band corresponding to the case where the third state shifted to the side (indicated as after the wavelength shift in FIG. 6) is reached.

In other words, in the fourth embodiment, the filter for wavelength shift detection 46 is a band corresponding to the case where the laser light of the “desired wavelength band” is emitted from the light source 43 to the long wavelength side and emitted. It has a "blocking band" for blocking light of "wavelength band shifted to the long wavelength side".

When the laser light in the “desired wavelength band” is emitted from the light source 43 while being shifted to the long wavelength side, the filter for wavelength shift detection 46 in the fourth embodiment is the diagram described in the first embodiment. As shown in FIG. 1, the reflected light OP2 from the half mirror 44 is incident, but the transmission of the reflected light OP2 is blocked by the "blocking band".

At this time, the light sensor 47 detects that the laser light emitted from the light source 43 has shifted to the long wavelength side by not receiving the shifted laser light.

More specifically, when the red laser light of the center wavelength (for example, 600 [nm]) emitted from the light source 43 is normally output, the filter 46 for wavelength shift detection in the fourth embodiment is a half. The shifted reflected light OP2 reflected by the mirror 44 is transmitted, and is output to the light sensor 47 as a reflected light OP3 (see FIG. 2).

On the other hand, it is assumed that the red laser light of the central wavelength (e.g., 600 [nm]) emitted from the light source 43 is shifted to the long wavelength side by a predetermined wavelength (e.g., about 5 [nm]). At this time, the wavelength shift detection filter 46 blocks the shifted reflected light OP2 reflected by the half mirror 44 (see FIG. 1).

In the optical sensor 47, since the incoming light of the reflected light OP3 (which is the laser light in the normal state) which has been received until then is interrupted, the value of the voltage related to the reflected light also changes. The light sensor 47 detects the change in the voltage value to detect that the red laser light emitted from the light source 43 is out of the “desired wavelength band” and shifted to the long wavelength side.

In the above-mentioned specific example, the red laser light of the central wavelength (for example, 600 [nm]) is shifted to the long wavelength side. However, the light source device of the fourth embodiment is the second embodiment. As in the embodiment, even when the laser light of another color (green laser light or blue laser light) is shifted to the long wavelength side, the wavelength shift in the light sensor 47 corresponding to the green semiconductor laser and the blue semiconductor laser Can be detected.

As described above, even with the light source device of the fourth embodiment, the wavelength of the light emitted from the light source is shifted from the desired wavelength band to the long wavelength side even in the light source device not using the phosphor. Can be detected.

Fifth Embodiment
Next, a fifth embodiment of the present invention will be described.

FIG. 7 is a view showing a configuration of an endoscope system including a light source device according to a fifth embodiment of the present invention, and FIG. 8 is a view showing a desired light source irradiated from a light source in the light source device according to the fifth embodiment. It is the figure which showed a mode when the light of the wavelength zone | band shifted. Further, FIG. 9 shows the transition of the wavelength between the first state before the wavelength shift and the second state after the wavelength shift (after the shift to the short wavelength side) in the light source device of the fifth embodiment, It is the figure which showed the relationship between the permeation | transmission band (normality) and the reflection band (shift) in a wavelength band limitation part.

As described above, in the light source device of the first embodiment, the half mirror 44 is disposed on the optical path OP1 of the laser light emitted from the light source 43. The half mirror 44 in the first embodiment is a light control unit that changes the state of light to be output according to the wavelength of the incident light (R light, G light, B light), and the light source 43 Has a function as an optical path separation unit that separates the emitted light (R light, G light, B light) into transmitted light and reflected light, respectively (see FIGS. 1 and 2).

In addition, when light of a “desired wavelength band” enters as the reflected light on the optical path OP2 of the reflected light reflected by the half mirror 44 in the first embodiment, the “desired wavelength band” A wavelength shift detection filter 46 having a function as a light control unit that differs in the state of the light to be output when the shifted light shifted to the short wavelength side by a certain wavelength from the light of FIG. 1, see Figure 2).

On the other hand, the light source device of the fifth embodiment is characterized in that a dichroic mirror 244 as a light control unit is disposed on the optical path OP11 of the laser light emitted from the light source 43.

As shown in FIG. 7, an endoscope system 1 having a light source device according to the fifth embodiment includes an endoscope 2 for observing an object and outputting an imaging signal, as in the first embodiment. A video processor 3 connected to the endoscope 2 to input the imaging signal and perform predetermined image processing, a light source device 204 for supplying illumination light for illuminating the subject, and an observation image according to the imaging signal And a monitor device 5 for displaying.

Also in the fifth embodiment, the endoscope 2 is disposed on the image forming plane of the objective optical system 21 and the objective optical system 21 including a lens for entering an object image, which is disposed at the distal end of the insertion portion. The imaging device 22 is provided, and the illumination unit 23 capable of emitting predetermined illumination light to a subject.

Further, the image pickup device 22 is formed of, for example, a CMOS image sensor, forms an optical image from a subject on the image pickup surface, photoelectrically converts light incident on each pixel in a photoelectric conversion unit, and converts a predetermined image pickup signal. It is designed to output.

Furthermore, the illumination unit 23 is disposed at the tip of the light guide 24 extending from the light source device 204 to the inside of the endoscope 2, and emits illumination light generated by the light source device 204. There is.

In the fifth embodiment, the video processor 3 includes a processor control unit 31 that controls various circuits in the connected endoscope 2 and light source device 204 in addition to the video processor 3, and an image signal from the endoscope 2. It comprises an image processing unit 32 for inputting and performing predetermined image processing, and a video output unit 33 for inputting an image signal processed by the image processing unit 32 and generating a video signal for displaying on the monitor device 5 .

<Configuration of light source device>
In the fifth embodiment, the light source device 204 includes a light source 243 that generates (emits) laser light with a predetermined center wavelength, and further, a drive unit 242 that drives the light source 243 and light emission control of the light source 243 Mainly comprises a light source device control unit 241 that

Also in the fifth embodiment, the light source 243 is a solid-state light source configured of three semiconductor lasers (laser diode LD; laser diode) of a red semiconductor laser, a green semiconductor laser, and a blue semiconductor laser. And under the control of the light source device control unit 241, the drive unit 242 is driven to emit red, green and blue laser beams, respectively.

FIGS. 7 and 8 show the configuration relating to the semiconductor laser of one color among the three-color semiconductor lasers in the light source 243. That is, the red semiconductor laser, the green semiconductor laser and the blue semiconductor laser all have the same configuration, and the emission light path, the dichroic mirror 244 described later and the light sensor 247 have the same configuration for each color semiconductor laser. It shall be.

Thus, the light source 243 serves as a light source unit for generating (emitting) light of at least a part of the desired wavelength band.

In the fifth embodiment, the dichroic mirror 244 is disposed on the optical path OP11 of the laser light emitted from the light source 243 (red semiconductor laser, green semiconductor laser and blue semiconductor laser). As described above, the dichroic mirror 244 is disposed on the optical path OP11 of each of the red, green and blue semiconductor lasers, but in FIGS. 7 and 8, one optical path system is used. Only for illustration.

The dichroic mirror 244 is a light control unit that changes the state of light to be output according to the state (normal state or shifted state) of the incident light (R light, G light, B light). A wavelength band limiting unit that outputs light of a desired wavelength band (normal laser light) as transmitted light and reflects light of a wavelength band other than the desired wavelength band (shifted laser light) as reflected light It has a function.

A condenser lens 245 is disposed on the optical path of the transmitted light (R light, G light, B light) transmitted through the dichroic mirror 244 in each optical path system. That is, the light (R light, G light, B light) transmitted through the dichroic mirror 244 is all condensed by the condensing lens 245, and thereafter, from the illumination unit 23 of the endoscope 2 via the light guide 24 It is supposed to be irradiated.

On the other hand, the reflected light from the dichroic mirror 244 is received on the optical path OP12 of the reflected light (R light, G light, B light) which is each shifted laser light reflected by the dichroic mirror 244, and the received light is received And a light sensor (detection unit) 247 that detects a change in the value of the voltage.

As for the semiconductor laser, as described above, the wavelength band of the light emitted from the semiconductor laser light source may be shifted due to the influence of the fluctuation of the drive current or the change of the ambient temperature, etc. It is known that there is.

FIG. 9 shows the wavelength transition between the first state before wavelength shift and the second state after wavelength shift (after shift to the short wavelength side) and the wavelength band in the light source device of the fifth embodiment. It is the figure which showed the relationship of the transmission zone (normality) and the reflection zone (shift) in a restriction | limiting part.

As shown in FIG. 9, in the fifth embodiment, the dichroic mirror 244 transmits at least a “transmission band” that transmits light (a normal laser light) of a “desired wavelength band” emitted from the light source 243; A “reflection band” is formed to reflect light in a band shorter than the “desired wavelength band” (shifted laser light).

In the “transmission band” of the dichroic mirror 244 in the fifth embodiment, the laser light (one of R light, G light, and B light as described above) emitted from the light source 243 is in a first normal state (FIG. 9 is a band corresponding to the case of “before wavelength shift”.

In other words, in the fifth embodiment, the dichroic mirror 244 serves as a band corresponding to the case where normal laser light of the “desired wavelength band” is emitted from the light source 243, and light of this “desired wavelength band” Have a “transmission band” that transmits light.

When the normal laser light of the "desired wavelength band" is emitted from the light source 243, the dichroic mirror 244 in the fifth embodiment is, as shown in FIG. Through and output. At this time, the laser light (normal laser light) emitted from the light source 243 does not enter the light sensor 247.

On the other hand, in the “reflection band” of the dichroic mirror 244 in the fifth embodiment, the laser light of at least one color of the laser light (R light, G light, B light) emitted from the light source 243 is shifted to the short wavelength side This is a band corresponding to the case where the second state (indicated as after the wavelength shift in FIG. 9) is reached.

In other words, in the fifth embodiment, the dichroic mirror 244 serves as a band corresponding to the case where the laser light of the “desired wavelength band” is emitted from the light source 243 while shifting to the short wavelength side. It has a "reflection band" that reflects the light of the wavelength band shifted to the side.

When the laser light of the “desired wavelength band” is shifted to the short wavelength side and emitted from the light source 243, the dichroic mirror 244 reflects the incident laser light as shown in FIG. Output as

At this time, the laser light (shifted laser light) emitted from the light source 243 and reflected from the dichroic mirror 244 is input to the light sensor 247. Accordingly, the light sensor 247 detects that the laser light emitted from the light source 243 has shifted to the short wavelength side by receiving the shifted laser light.

More specifically, it is assumed that the red laser light of the center wavelength (for example, 600 [nm]) emitted from the light source 243 is shifted to the short wavelength side by a predetermined wavelength (for example, about 5 [nm]). . At this time, the dichroic mirror 244 outputs the shifted laser light to the optical sensor 247 as the reflected light OP12.

The light sensor 247 receives the reflected light OP12 that is the shifted laser light, converts the received light OP12 into a voltage, and detects a change in the value of the voltage. Thus, the light sensor 247 detects that the red laser light emitted from the light source 243 is out of the “desired wavelength band” and shifted to the short wavelength side.

In addition, the specific example mentioned above gave the example which the red laser beam of center wavelength (for example, 600 [nm]) shifted to the short wavelength side. However, the light source device of the fifth embodiment corresponds to the green semiconductor laser and the blue semiconductor laser even when the laser light of other colors (green laser light and blue laser light) is shifted to the short wavelength side. The optical sensor 247 can detect the wavelength shift.

As described above, according to the light source device of the fifth embodiment, the wavelength of the light emitted from the light source is shifted from the desired wavelength band to the short wavelength side even in the light source device which does not use the phosphor. Can be detected.

In the fifth embodiment, an example is given of detecting that the wavelength of the light emitted from the light source is shifted from the desired wavelength band to the short wavelength side. However, the present invention is not limited to this. It is also possible to detect that the wavelength of the light emitted from the light source has shifted from the desired wavelength band to the long wavelength side.

According to the present invention, it is possible to provide a light source device capable of detecting that the wavelength of light emitted from the light source deviates from a desired wavelength band, even if the light source device does not use a phosphor.

The present invention is not limited to the above-described embodiment, and it goes without saying that various changes, modifications, and the like can be made without departing from the scope of the present invention.

This application is based on Japanese Patent Application No. 2017-212140 filed on Nov. 1, 2017 as a basis for claiming priority, and the above disclosure is incorporated herein by reference. It shall be quoted.

Claims

A light source unit for generating light of at least a part of wavelength bands in a desired wavelength band;
A light control unit which is disposed on a predetermined optical path of the light generated by the light source unit and which makes the state of light to be output different according to the wavelength of the incident light;
A detection unit that receives the light output from the light control unit, converts the received light into a voltage, and detects a change in the value of the voltage;
A light source device comprising:
The light control unit makes the state of the light to be output different between when the light of the desired wavelength band is input and when the shifted light whose wavelength is shifted from the light of the desired wavelength band is input. The light source device according to claim 1, characterized in that
The light source unit may further include an optical path separation unit disposed on an optical path of the light generated and separating the light into transmitted light and reflected light.
The light source device according to claim 2, wherein the light control unit is disposed on the light path of the reflected light separated by the light path separation unit, and receives the reflected light.
The light control unit includes a wavelength band limiting unit that limits transmission of light in the desired wavelength band,
The said detection part is arrange | positioned in the position which light-receives the light which permeate | transmitted the said wavelength zone limiting part, converts the said received light into a voltage, and detects the change of the value of the said voltage. The light source device as described.
The detection unit detects that the wavelength of light generated from the light source unit is shifted from the desired wavelength band when the value of the voltage exceeds a predetermined value. The light source device as described.
The wavelength band limiting unit in the light control unit blocks light of at least the desired wavelength band and transmits light of a wavelength shorter than the desired wavelength band. Light source device.
The wavelength band limiting section in the light control section blocks light of at least the desired wavelength band and transmits light of a wavelength longer than the desired wavelength band. Light source device.
The wavelength band limiting unit in the light control unit transmits light of at least the desired wavelength band and blocks light of a wavelength shorter than the desired wavelength band. Light source device.
The wavelength band limiting section in the light control section blocks light of at least the desired wavelength band and transmits light of a wavelength longer than the desired wavelength band. Light source device.
The light control unit includes a wavelength band limiting unit that outputs the light of the desired wavelength band as transmitted light and reflects the light of wavelength bands other than the desired wavelength band as reflected light.
The detection unit is disposed at a position for receiving the light reflected by the wavelength band limiting unit, converts the received light into a voltage, and detects a change in the value of the voltage. The light source device as described.
The detection unit detects that the wavelength of light generated from the light source unit has shifted from the desired wavelength band when the value of the voltage exceeds a predetermined value. The light source device as described.
The wavelength band limiting unit in the light control unit transmits light of at least the desired wavelength band and reflects light of a wavelength shorter than the desired wavelength band. Light source device.
The wavelength band limiting unit in the light control unit transmits light of at least the desired wavelength band and reflects light of a wavelength longer than the desired wavelength band. Light source device.
The light source unit includes a first light source unit that generates a first light, and a second light source unit that generates a second light different from the first light.
It is disposed on the optical path of the first light and the second light to separate the first light into a first transmitted light and a first reflected light, and the second light is divided into a first light and a second reflected light. An optical path separation unit for separating into two transmitted light and second reflected light;
The light detector is positioned on the light path of the first transmitted light and is positioned on the light path of the second transmitted light, the first light detector being irradiated with the first transmitted light The light source device according to claim 1, further comprising: a second light detector to be irradiated with the second transmitted light.
The light source unit includes a first light source unit that generates a first light, and a second light source unit that generates a second light different from the first light.
It is disposed on the optical path of the first light and the second light to separate the first light into a first transmitted light and a first reflected light, and the second light is divided into a first light and a second reflected light. An optical path separation unit for separating into two transmitted light and second reflected light;
The light detector is positioned on the light path of the first reflected light and is positioned on the light path of the second reflected light, the first light detector being irradiated with the first reflected light The light source device according to claim 1, further comprising: a second light detector to be irradiated with the second reflected light.