Patent Publication Number: US-2020281452-A1

Title: Medical light source device

Description:
This application claims priority from Japanese Application No. 2019-041884, filed on Mar. 7, 2019, the contents of which are incorporated by reference herein in its entirety. 
     BACKGROUND 
     The present disclosure relates to a medical light source device. 
     There are known, in medical fields and industrial fields, medical devices such as an endoscope device that captures a subject image using an image sensor, and a medical microscope device (refer to JP 2016-202441 A, for example). An endoscope device, among these, includes an endoscope, an imaging device, a display device, a control device (image processing device), and a light source device, for example. In an endoscope device, illumination light is supplied from a light source device via a light guide connected to the endoscope, and the illumination light is applied to capture a subject image. 
     The light source device includes a light source, an optical system that guides light from the light source, and a light source including a light emitter and an optical fiber that guides light from the light emitter to the optical system. In order to protect an emitting end surface, a distal end surface of an optical fiber on the light emission side is polished to have a protrusion, an inclined surface, or a diagonal spherical shape, thereby suppressing the incident of return light of the light emitted from the own fiber. However, since the distal end surface of the optical fiber is inclined with respect to the longitudinal direction of the fiber, vignetting might occur and the desired amount of light to emit might not be ensured in some cases. To deal with this problem, JP 2016-202441 A describes a technique of providing a detecting portion for detecting the amount of light on an optical path so as to control the amount of light emitted from the light source device. 
     SUMMARY 
     However, the detecting portion described in JP 2016-202441 A is provided outside the light source device and performs the detection processing by arranging the detection unit in the optical path, disabling detection of the amount of light during observation with the endoscope. On the other hand, providing a detecting portion using another member as disclosed in JP 2016-202441 A would complicate the configuration of the entire system. 
     There is a need for a medical light source device capable of detecting the amount of light emitted from the light source device even during the use of the medical device. 
     According to one aspect of the present disclosure, there is provided a medical light source device including: a first light emitting device configured to emit light; an optical member provided on an optical path of the light emitted from the first light emitting device, and configured to emit a part of the light emitted by the first light emitting device in a first direction and emit rest of the light in a second direction different from the first direction; an illumination optical system provided on the optical path of the light emitted in the first direction by the optical member and configured to guide incident light to be emitted to an outside; a detector disposed on the optical path of the light emitted in the second direction by the optical member and configured to detect an amount of incident light; and an optical path changer configured to change the optical path of the light emitted from the first light emitting device in accordance with the amount of light detected by the detector. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating a configuration of an endoscope device according to a first embodiment; 
         FIG. 2  is a block diagram illustrating a configuration of a camera head and a control device illustrated in  FIG. 1 ; 
         FIG. 3  is a view illustrating a configuration of a light source device illustrated in  FIG. 1 ; 
         FIG. 4  is a view illustrating a configuration of a light source device, which is in a state before optical axis adjustment; 
         FIG. 5  is a diagram illustrating illumination light control performed by the endoscope device according to the first embodiment; 
         FIG. 6  is a view illustrating a configuration of a light source device included in an endoscope device according to a second embodiment; 
         FIG. 7  is a view illustrating a configuration of a light source device included in an endoscope device according to a third embodiment; 
         FIG. 8  is a view illustrating a configuration of a light source device included in an endoscope device according to a fourth embodiment; 
         FIG. 9  is a diagram illustrating a wavelength of light emitted from the light source device according to the fourth embodiment; and 
         FIG. 10  is a view illustrating a configuration of a light source device included in an endoscope device according to a fifth embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a mode for carrying out the present disclosure (hereinafter referred to as “embodiment”) will be described. In the embodiment, a medical endoscope device that captures and displays an image inside a subject such as a patient will be described as an example of a system including a medical light source device according to the present disclosure. The present disclosure is not limited by the present embodiment. In the description of the drawings, the identical reference numerals will be used to denote identical portions. 
     First Embodiment 
       FIG. 1  is a schematic view illustrating a configuration of an endoscope device  1  according to a first embodiment. The endoscope device  1  is a device that is used in medical fields and observes a subject inside an observation target such as a person (inside a living body). As illustrated in  FIG. 1 , the endoscope device  1  includes an endoscope  2 , an imaging device  3 , a display device  4 , a control device  5  (image processing device), and a light source device  6 . The imaging device  3  and the control device  5  constitute a medical observation system. In the first embodiment, the endoscope  2  and the imaging device  3  constitute an image acquisition device using an endoscope such as a rigid endoscope. 
     The light source device  6  is connected to one end of a light guide  7 , and includes: a light source unit  61  that supplies the one end of the light guide  7  with white light for illuminating the inside of the living body; and a light source controller  62  that controls emission of illumination light by the light source unit  61 . The configuration of the light source device  6  will be described below. As illustrated in  FIG. 1 , the light source device  6  and the control device  5  may have a separate configuration and communicate with each other, or may have an integrated configuration. The light source controller  62  corresponds to an optical path changer. 
     The light guide  7  has one end detachably connected to the light source device  6  and the other end detachably connected to the endoscope  2 . The light guide  7  transmits the light supplied from the light source device  6  from one end to the other end of the light guide  7  and supplies the light to the endoscope  2 . 
     The imaging device  3  captures a subject image from the endoscope  2  and outputs a result of imaging. As illustrated in  FIG. 1 , the imaging device  3  includes a transmission cable  8  that is a signal transmission unit, and a camera head  9 . In the first embodiment, the transmission cable  8  and the camera head  9  constitute a medical imaging device. 
     The endoscope  2  is rigid and has an elongated shape, and is inserted into a living body. The endoscope  2  internally includes an observation optical system that uses one or more lenses to focus a subject image. The endoscope  2  emits light supplied via the light guide  7  from its distal end and applies the light to the inside of the living body. The light (subject image) directed to the inside of the living body is collected by the observation optical system (lens unit  91 ) in the endoscope  2 . 
     The camera head  9  is detachably connected to a proximal end of the endoscope  2 . Under the control of the control device  5 , the camera head  9  captures a subject image focused by the endoscope  2 , and outputs an imaging signal obtained by the imaging. A detailed configuration of the camera head  9  will be described below. The endoscope  2  and the camera head  9  may have a detachable configuration as illustrated in  FIG. 1 , or may have an integrated configuration. 
     The transmission cable  8  has one end detachably connected to the control device  5  via a connector, with the other end detachably connected to the camera head  9  via a connector. Specifically, the transmission cable  8  is a cable having a plurality of electrical wires (not illustrated) disposed inside an outer jacket being an outermost layer. The plurality of electrical wires is used to transmit an imaging signal output from the camera head  9  to the control device  5 , and transmit each of a control signal, a synchronization signal, a clock, and power output from the control device  5  to the camera head  9 . 
     The display device  4  displays an image generated by the control device  5  under the control of the control device  5 . The display device  4  preferably has a display unit having a size of 55 inches or more in order to easily obtain an immersive feeling during observation, but is not limited to this size. 
     The control device  5  processes the imaging signal input from the camera head  9  via the transmission cable  8 , outputs the image signal to the display device  4 , and comprehensively controls the operation of the camera head  9  and the display device  4 . The detailed configuration of the control device  5  will be described below. 
     Next, configurations of the imaging device  3  and the control device  5  will be described.  FIG. 2  is a block diagram illustrating a configuration of the camera head  9  and the control device  5 . Note that  FIG. 2  omits illustration of a connector that detachably connects the camera head  9  and the transmission cable  8 . 
     Hereinafter, the configuration of the control device  5  and the configuration of the camera head  9  will be described in this order. The following will mainly described major portions as a configuration of the control device  5 . As illustrated in  FIG. 2 , the control device  5  includes a signal processing unit  51 , an image processing unit  52 , a communication module  53 , an input unit  54 , an output unit  55 , a control unit  56 , and memory  57 . The control device  5  may include a power supply unit (not illustrated) that generates a power supply voltage for driving the control device  5  and the camera head  9 , supplies the generated voltage to individual portions of the control device  5  while supplying the generated voltage to the camera head  9  via the transmission cable  8 . 
     The signal processing unit  51  performs signal processing such as noise removal and A/D conversion as necessary on an imaging signal output from the camera head  9 , and thereby outputs digitized imaging signals (pulse signals) to the image processing unit  52 . 
     The signal processing unit  51  also generates a synchronization signal and clocks for the imaging device  3  and the control device  5 . A synchronization signal (for example, a synchronization signal for instructing an imaging timing of the camera head  9 ) or a clock (for example, a clock for serial communication) to the imaging device  3  is transmitted to the imaging device  3  by a line (not illustrated). The imaging device  3  is driven on the basis of the synchronization signal and the clock. 
     The image processing unit  52  generates a display image signal to be displayed on the display device  4  on the basis of the imaging signal input from the signal processing unit  51 . The image processing unit  52  executes predetermined signal processing on the imaging signal, and thereby generates a display image signal including a subject image. Here, the image processing unit  52  performs known image processing including various types of image processing such as demodulation processing, interpolation processing, color correction processing, color enhancement processing, or edge enhancement processing. The image processing unit  52  outputs the generated image signal to the display device  4 . 
     The communication module  53  outputs a signal from the control device  5  including a control signal to be described below transmitted from the control unit  56  to the imaging device  3 . The communication module  53  also outputs a signal from the imaging device  3  to individual portions in the control device  5 . That is, the communication module  53  is implemented as a relay device that collectively outputs the signals from the individual portions of the control device  5  to be output to the imaging device  3  by using parallel-to-serial conversion, for example, and outputs the signals input from the imaging device  3  to be distributed to individual portion of the control device  5  by using serial-to-parallel conversion, for example. 
     The input unit  54  is implemented as a user interface such as a keyboard, a mouse, and a touch panel, and receives inputs of various types of information. 
     The output unit  55  is implemented by using a speaker, a printer, a display, or the like, and outputs various types of information. The output unit  55  outputs alarm sound and alarm light, or displays an image under the control of the control unit  56 . 
     The control unit  56  performs drive control of individual components including the control device  5  and the camera head  9 , input/output control of information for individual components, or the like. The control unit  56  generates a control signal with reference to communication information data (for example, communication format information) recorded in the memory  57 , and then transmits the generated control signal to the imaging device  3  via the communication module  53 . The control unit  56  also outputs a control signal to the camera head  9  via the transmission cable  8 . 
     The memory  57  is implemented by semiconductor memory such as flash memory or Dynamic Random Access Memory (DRAM), and records communication information data (for example, communication format information). The memory  57  may record various programs executed by the control unit  56 . 
     The signal processing unit  51  may include an AF processing unit that outputs a predetermined AF evaluation value for each of frames on the basis of the input imaging signal of the frame, and an AF arithmetic unit that performs AF arithmetic processing of selecting a frame or a focus lens position most suitable as a focus position, from the AF evaluation values for each of frames output from the AF processing unit. 
     The above-described signal processing unit  51 , the image processing unit  52 , the communication module  53 , and the control unit  56  are implemented by using a general-purpose processor such as a central processing unit (CPU) having internal memory (not illustrated) in which a program is recorded, or a dedicated processor such as various arithmetic circuits that executes specific function, such as an Application Specific Integrated Circuit (ASIC). The above-described units may be implemented by using a Field Programmable Gate Array (FPGA, not illustrated), a type of programmable integrated circuit. In a case where an FPGA is used, it is allowable to provide memory for storing configuration data and to achieve configuration of the FPGA which is a programmable integrated circuit on the basis of configuration data read from the memory. 
     Next, major portions will be mainly described, as a configuration of the camera head  9 . As illustrated in  FIG. 2 , the camera head  9  includes a lens unit  91 , an imaging unit  92 , a communication module  93 , and a camera head controller  94 . 
     The lens unit  91  includes one or more lenses, and forms a subject image that has passed through the lens unit  91  on an imaging surface of an image sensor included in the imaging unit  92 . The one or more lenses are movable along the optical axis. The lens unit  91  includes an optical zoom mechanism (not illustrated) that changes the angle of view by moving the one or more lenses, and a focus mechanism that changes the focal position. The lens unit  91  also forms an observation optical system that guides the observation light incident on the endoscope  2  to the imaging unit  92 , together with the optical system provided in the endoscope  2 . 
     The imaging unit  92  captures a subject image under the control of the camera head controller  94 . The imaging unit  92  includes an image sensor that receives a subject image formed by the lens unit  91  and converts the image into an electrical signal. The image sensor is implemented by a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor. In a case where the image sensor is a CCD, for example, a signal processing unit (not illustrated) that performs signal processing (A/D conversion, etc.) on an electrical signal (analog signal) from the image sensor and outputs an imaging signal is mounted on a sensor chip or the like. In a case where the image sensor is a CMOS sensor, for example, a signal processing unit (not illustrated) that performs signal processing (A/D conversion, etc.) on an electrical signal (analog signal) obtained by converting light to the electrical signal and that outputs an imaging signal is included in the image sensor. The imaging unit  92  outputs the generated electrical signal to the communication module  93 . 
     The communication module  93  outputs a signal transmitted from the control device  5  to individual portions in the camera head  9  such as the camera head controller  94 . The communication module  93  also converts information regarding the current state of the camera head  9 , or the like, into a signal format corresponding to a predetermined transmission scheme, and outputs the converted signal to the control device  5  via the transmission cable  8 . That is, the communication module  93  is a relay device that distributes the signals input from the control device  5  and the transmission cable  8  by serial-to-parallel conversion, for example, and outputs the signal to individual portions of the camera head  9  as well as collectively outputting, by parallel-to-serial conversion for example, the signals from individual portion of the camera head  9  to be output to the control device  5  and the transmission cable  8 . 
     The camera head controller  94  the controls overall operation of the camera head  9  in accordance with signals such as the drive signal input via the transmission cable  8 , or an instruction signal output from an operating unit by user&#39;s operation to the operating unit such as a switch provided to be exposed on an outer surface of the camera head  9 . The camera head controller  94  also outputs information regarding the current state of the camera head  9  to the control device  5  via the transmission cable  8 . 
     The above-described communication module  93  and the camera head controller  94  are implemented by a general-purpose processor such as a CPU having internal memory (not illustrated) in which a program is recorded, and a dedicated processor such as various arithmetic circuits that execute specific functions, such as an ASIC. The above-described units may be implemented by using an FPGA, which is a type of programmable integrated circuit. Here, in a case where an FPGA is used, it is allowable to provide memory for storing configuration data and to achieve configuration of the FPGA which is a programmable integrated circuit on the basis of configuration data read from the memory. 
     In addition, the camera head  9  and the transmission cable  8  may include a signal processing unit that performs signal processing on an imaging signal generated by the communication module  93  or the imaging unit  92 . Furthermore, an imaging clock for driving the imaging unit  92  and a control clock for the camera head controller  94  may be generated on the basis of a reference clock generated by an oscillator (not illustrated) provided in the camera head  9  so as to be each output to each of the imaging unit  92  and the camera head controller  94 . Timing signals for various types of processing in the imaging unit  92  and the camera head controller  94  may be generated on the basis of the synchronization signal input from the control device  5  via the transmission cable  8  so as to be each output to each of the imaging unit  92  and the camera head controller  94 . The camera head controller  94  may be provided in the transmission cable  8  or the control device  5  instead of in the camera head  9 . 
     Next, the configuration of the light source device  6  will be described with reference to  FIG. 3 .  FIG. 3  is a view illustrating a configuration of the light source device  6  illustrated in  FIG. 1 . The light source unit  61  includes an emission unit  611 , a first mirror  612 , a second mirror  613 , a pinhole  614 , a reflection filter  615 , a condenser lens  616 , and a detection unit  617 . Each of these units is provided inside a casing constituting the light source device  6 . In the first embodiment, the emission unit  611  corresponds to a first emission unit, the first mirror  612  and the second mirror  613  correspond to a folded optical system, the condenser lens  616  corresponds to an illumination optical system, and the reflection filter  615  corresponds to an optical member. 
     The emission unit  611  includes a laser light source  611   a  and an optical fiber  611   b . White light (laser light) emitted from the laser light source  611   a  is guided to one end of the optical fiber  611   b  and emitted from the other end of the optical fiber  611   b.    
     The first mirror  612  and the second mirror  613  reflect incident light. The first mirror  612  reflects the light emitted from the emission unit  611  (optical fiber  611   b ). The light reflected by the first mirror  612  is incident on the second mirror  613 , which then reflects the incident light. The first mirror  612  and the second mirror  613  can alter the direction of the reflecting surface under the control of the light source controller  62 . For example, the angles of the first mirror  612  and the second mirror  613  are adjusted with respect to axes extending in different directions, for example, directions orthogonal to each other. Adjustment of the angles of the first mirror  612  and the second mirror  613  uses a piezo motor, for example. 
     The light reflected by the second mirror  613  passes through the pinhole  614 . The pinhole  614  has a hole having a preliminarily set diameter. 
     The reflection filter  615  folds a portion of the light traveling in an optical path in a direction different from an extending direction of the optical path and allows the rest of the light to pass. In the first embodiment, the reflection filter  615  reflects a preliminarily set proportion of light and allows the rest of the light to pass. In the first embodiment, the reflection filter  615  reflects 2% of light and allows 98% of the light to pass. The reflection filter  615  is provided in the optical path downstream of the pinhole  614  and upstream of the condenser lens  616 . 
     The condenser lens  616  includes one or more lenses, collects the light that has passed through the reflection filter  615 , and supplies the light guide  7  with the light. 
     The detection unit  617  includes an optical sensor, receives the light reflected by the reflection filter  615 , and converts the received light into an electrical signal. The electrical signal generated by the detection unit  617  is output to the light source controller  62 . 
     In the light source unit  61  described above, the light emitted from the emission unit  611  is reflected by the first mirror  612  and the second mirror  613 , and passes through the pinhole  614 . The light that has passed through the pinhole  614  is incident on the reflection filter  615 . 98% of the incident light passes and 2% of the light is reflected by the detection unit  617 . The light that has passed through the reflection filter  615  is collected by the condenser lens  616  so as to be incident on the light guide  7 . Meanwhile, the light incident on the detection unit  617  is converted into an electrical signal (signal value) indicating a value corresponding to the amount of light. 
     After receiving the electrical signal from the detection unit  617 , the light source controller  62  determines the necessity of adjustment of the first mirror  612  and the second mirror  613  on the basis of the signal value and a preliminarily set threshold. For example, the light source controller  62  calculates a difference between the signal value and the threshold, and determines the necessity of adjustment of the first mirror  612  and the second mirror  613  in accordance with the difference. The threshold is a value set, for example, as a value corresponding to a maximum received amount of light predicted from the output of the emission unit  611  (laser light source  611   a ), the amount of light passing through the pinhole  614 , and the reflection characteristics of the reflection filter  615 . The maximum received amount of light is the amount of light detected when the optical axis of light traveling in the optical path passes through the best position. An example of the best position would be a position where the optical axis passes through the center of the pinhole  614  (hole). This maximum received amount of light corresponds to a target amount of light. 
     In a case where the light source controller  62  determines that adjustment of the first mirror  612  and the second mirror  613  is necessary, the light source controller  62  changes the angle of the first mirror  612  and/or the second mirror  613  in accordance with the magnitude of the difference. The movements of the first mirror  612  and the second mirror  613  are preliminarily associated with each other. In a case where the target amount of light has not reached by performing angle alteration processing one time, the light source controller  62  adjusts the angle to obtain the maximum received amount of light by repeatedly performing the angle alteration processing. 
       FIG. 4  is a view illustrating a configuration of a light source device, which is in a state before optical axis adjustment. As illustrated in  FIG. 4 , in a case where the optical path deviates and the amount of light to be incident on the detection unit  617  or the condenser lens  616  is small or even no light is incident on the detection unit  617  or the condenser lens  616 , the amount of light to be supplied from the light source device  6  to the light guide  7  would be below a set amount. In this case, the light source controller  62  changes the angle of the first mirror  612  and/or the second mirror  613  on the basis of the electrical signal from the detection unit  617 . In the example illustrated in  FIG. 4 , the angle is changed in the first mirror  612  alone (refer to the broken line superimposed on the first mirror  612 ). Changing the angle of the first mirror  612  under the control of the light source controller  62  will adjust the optical axis of the light emitted from the emission unit  611  (refer to  FIG. 3 ). 
       FIG. 5  is a diagram illustrating illumination light control performed by the endoscope device according to the first embodiment. In a case where the optical axis deviates from the center of the optical path (axis N), where the optical axis should pass, such as when the optical axis of the emitted light is inclined with respect to the longitudinal direction of the optical fiber, due to the shape of the light emitting end of the emission unit  611  (optical fiber  611   b ), the peak of the light distribution (distribution C 1  illustrated in  FIG. 5 ) would deviate from the axis N. Traveling through the optical path with deviation in the light distribution (optical axis) would cause problems such as unnecessary level of vignetting of the light at the pinhole  614  or occurrence of non-collection of the light by the condenser lens  616 , leading to a failure in ensuring the intensity as the illumination light. In the first embodiment, the light source controller  62  alters the angles of the first mirror  612  and the second mirror  613  on the basis of the detection result of the detection unit  617 . This will shift the peak of the light distribution to the axis N side (distribution C 2  illustrated in  FIG. 5 ). In this manner, the optical axis of the light is controlled so as to approach the ideal optical path to pass through, it is possible to make adjustment so as to ensure the intensity as the illumination light. 
     In the first embodiment described above, the reflection filter  615  is used to allow a part of the light guided to the condenser lens  616  to be incident on the detection unit  617 . This makes it possible to detect the amount of light emitted from the light source device  6  even during the use of the endoscope. 
     According to the first embodiment described above, the angles of the first mirror  612  and the second mirror  613  are controlled on the basis of the detection result of the detection unit  617 . This controls the optical axis of the light so as to approach the ideal optical path to pass through, making it possible to achieve adjustment so as to ensure the intensity as illumination light. 
     Second Embodiment 
     Next, a second embodiment will be described.  FIG. 6  is a view illustrating a configuration of a light source device included in an endoscope device according to the second embodiment. In the second embodiment, the configuration other than the light source unit  61  is the same as that of the endoscope device  1  of the first embodiment described above, and thus the description thereof will be omitted. 
     The light source unit illustrated in  FIG. 6  includes an emission unit  611 A, the first mirror  612 , the second mirror  613 , a reflection filter  615 A, the condenser lens  616 , and a detection unit  617 . Differences in the light source unit according to the second embodiment from the light source unit  61  according to the first embodiment exist in the light emitted from the emission unit  611 A and the reflection characteristics of the reflection filter  615 A. Other configurations are the same as those in the first embodiment. Hereinafter, portions different from the first embodiment will be described. In the second embodiment, the emission unit  611 A corresponds to the first emission unit, and the reflection filter  615 A corresponds to an optical member. 
     The emission unit  611 A includes a laser light source  611   c  and an optical fiber  611   d , and light (laser light) emitted from a laser light source  611   c  is guided to one end of an optical fiber  611   d  and emitted from the other end of the optical fiber  611   d . The emission unit  611 A emits light (infrared light) in a wavelength band of 500 nm or more and 700 nm or less. 
     The reflection filter  615 A reflects light of a preliminarily set wavelength or less. In the second embodiment, the reflection filter  615 A reflects light having a wavelength of 600 nm or less and allows light having a wavelength greater than 600 nm to pass. 
     The detection unit  617  receives the light reflected by the reflection filter  615 A and converts the received light into an electrical signal. The electrical signal generated by the detection unit  617  is output to the light source controller  62 . 
     After receiving the electrical signal from the detection unit  617 , the light source controller  62  determines the necessity of adjustment of the first mirror  612  and the second mirror  613  on the basis of the signal value and a preliminarily set threshold. For example, the light source controller  62  calculates a difference between the signal value and the threshold, and determines the necessity of adjustment of the first mirror  612  and the second mirror  613  in accordance with the difference. The threshold is a value set, for example, as a value corresponding to a maximum received amount of light, with the wavelength band of 500 nm or more and 600 nm or less, predicted from the output of the emission unit  611 A (laser light source  611   c ) and from the reflection characteristics of the reflection filter  615 A. Specifically, the light source controller  62  changes the angle of the first mirror  612  and/or the second mirror  613  in accordance with the magnitude of the difference. The movements of the first mirror  612  and the second mirror  613  are preliminarily associated with each other. 
     In the second embodiment described above, the reflection filter  615  is used to allow a part of the light guided to the condenser lens  616  to be incident on the detection unit  617 . This makes it possible to detect the amount of light emitted from the light source device  6  even during the use of the endoscope. 
     Similarly to the first embodiment, according to the second embodiment described above, the angles of the first mirror  612  and the second mirror  613  are controlled on the basis of the detection result of the detection unit  617 . This makes it possible to control the optical axis of the light so as to approach the ideal optical path to pass through, enabling adjustment so as to ensure the intensity as illumination light. 
     In a case where white light is emitted from the endoscope  2  in the second embodiment described above, the light source unit  61  according to the first embodiment described above may be provided separately, or white light may be directly supplied from a light source that emits white light to the light guide. The light source that emits white light is not limited to a laser light source, and may use a semiconductor light source such as a light emitting diode (LED) light source. 
     Third Embodiment 
     Next, a third embodiment will be described.  FIG. 7  is a view illustrating a configuration of a light source device included in an endoscope device according to the third embodiment. In the third embodiment, the configuration other than the light source unit  61  is the same as that of the endoscope device  1  of the first embodiment described above, and thus the description thereof will be omitted. 
     The light source unit illustrated in  FIG. 7  includes a first emission unit  631 , a first mirror  632 , a second mirror  633 , a pinhole  634 , a first reflection filter  635 , a first collimating lens  636 , and a detection unit  637 , a second reflection filter  638 , a condenser lens  639 , a second emission unit  640 , and a second collimating lens  641 . In the third embodiment, the first emission unit  631  corresponds to a first emission unit, the first mirror  632  and the second mirror  633  correspond to a folded optical system, the condenser lens  639  corresponds to the illumination optical system, the first reflection filter  635  corresponds to an optical member, and the second emission unit  640  corresponds to a second emission unit. The first collimating lens  636 , the second reflection filter, and the second collimating lens  641  are appropriately arranged in accordance with the optical system to be formed. 
     The first emission unit  631  includes a laser light source  631   a  and an optical fiber  631   b , and light (laser light) emitted from the laser light source  631   a  is guided to one end of the optical fiber  631   b  and emitted from the other end of the optical fiber  631   b . The first emission unit  631  emits light (infrared light) in a wavelength band of 500 nm or more and 700 nm or less. 
     The first mirror  632  and the second mirror  633  reflect incident light. The first mirror  632  reflects the light emitted from the first emission unit  631  (optical fiber  631   b ). The light reflected by the first mirror  632  is incident on the second mirror  633 , which then reflects the incident light. The first mirror  632  and the second mirror  633  can change the direction of the reflecting surface under the control of the light source controller  62 . For example, the angles of the first mirror  632  and the second mirror  633  are adjusted with respect to axes extending in different directions, for example, directions orthogonal to each other. Adjustment of the angles of the first mirror  632  and the second mirror  633  uses a piezo motor, for example. 
     The light reflected by the second mirror  633  passes through the pinhole  634 . The pinhole  634  has an aperture having a preliminarily set diameter. 
     The first reflection filter  635  reflects light having a preliminarily set wavelength or less. In the third embodiment, the first reflection filter  635  reflects light having a wavelength of 600 nm or less and allows light having a wavelength greater than 600 nm to pass. The first reflection filter  635  is provided downstream of the pinhole  634  and upstream of the second reflection filter  638  in the optical path. 
     The first collimating lens  636  includes one or more lenses, and collimates the light that has passed through the first reflection filter  635  and guides the collimated light to the second reflection filter  638 . 
     The detection unit  637  includes an optical sensor, receives light reflected by the first reflection filter  635 , and converts the light into an electrical signal. The electrical signal generated by the detection unit  637  is output to the light source controller  62 . 
     The second reflection filter  638  reflects light having a preliminarily set wavelength or less. In the third embodiment, the second reflection filter  638  reflects light having a wavelength greater than 600 nm and allows light having a wavelength of 600 nm or less to pass. In a case where the light emission periods of the first emission unit  631  and the second emission unit  640  overlap with each other, the second reflection filter  638  functions as a combining member that combines the light beams emitted from individual units. 
     The condenser lens  639  includes one or more lenses, and collects the light emitted from the first emission unit  631  and reflected by the second reflection filter  638 , and the light emitted from the second emission unit  640  and that has passed through the second reflection filter  638 , and then, supplies the collected light to the light guide  7 . 
     The second emission unit  640  includes an LED light source that emits white light. The light emitted from the second emission unit  640  has a phase variation larger than the phase variation of the light emitted from the first emission unit  631 . 
     The second collimating lens  641  includes one or more lenses, and collimates the light emitted from the second emission unit  640  and guides the collimated light to the second reflection filter  638 . 
     In the light source unit described above, the light emitted from the first emission unit  631  is reflected by the first mirror  632  and the second mirror  633  and passes through the pinhole  634 . The light that has passed through the pinhole  634  is incident on the first reflection filter  635 . A part of the incident light passes through, and the rest of the light is reflected by the detection unit  637 . The light that has passed through the first reflection filter  635  passes through the first collimating lens  636  and the second reflection filter  638  and collected by the condenser lens  639 , so as to be incident on the light guide  7 . Meanwhile, the light incident on the detection unit  637  is converted into an electrical signal (signal value) indicating a value corresponding to the amount of light. 
     The light emitted from the second emission unit  640  passes through the second collimating lens  641  and the second reflection filter  638 , and collected by the condenser lens  639 , so as to be incident on the light guide  7 . 
     In the third embodiment, under the control of the light source controller  62 , one of observation modes, that is, either an infrared observation mode of performing observation with the light from the first emission unit  631  or a normal observation mode of performing observation with the light from the second emission unit  640  is selected. That is, in the third embodiment, either light having a wavelength band greater than 600 nm out of the light emitted from the first emission unit  631  and light having a wavelength band of 600 nm or less out of the light emitted from the second emission unit  640  is to be incident on and collected by the condenser lens  639 , so as to be incident on the light guide  7 . 
     After receiving the electrical signal from the detection unit  637  in the infrared observation mode, the light source controller  62  determines the necessity of adjustment of the first mirror  632  and the second mirror  633  on the basis of the signal value and a preliminarily set threshold. For example, the light source controller  62  calculates a difference between the signal value and the threshold, and determines the necessity of adjustment of the first mirror  632  and the second mirror  633  in accordance with the difference. The threshold is a value set, for example, as a value corresponding to a maximum received amount of light predicted from the output of the first emission unit  631  (laser light source), the amount of light passing through the pinhole  634 , and the reflection characteristics of the first reflection filter  635 . Specifically, the light source controller  62  changes the angle of the first mirror  632  and/or the second mirror  633  in accordance with the magnitude of the difference. The movements (inclination angle) of the first mirror  632  and the second mirror  633  are preliminarily associated with each other. 
     In the third embodiment described above, the first reflection filter  635  is used to allow a part of the light guided from the first emission unit  631  toward the condenser lens  639  to be incident on the detection unit  637 . This makes it possible to detect the amount of light emitted from the light source device  6  even during the use of the endoscope. 
     According to the third embodiment described above, the angles of the first mirror  632  and the second mirror  633  are controlled on the basis of the detection result of the detection unit  637 . This makes it possible to control the optical axis of the light so as to approach the ideal optical path to pass through, enabling adjustment so as to ensure the intensity as illumination light. 
     Fourth Embodiment 
     Next, a fourth embodiment will be described.  FIG. 8  is a view illustrating a configuration of a light source device included in an endoscope device according to the fourth embodiment. In the fourth embodiment, the configuration other than the light source unit  61  is the same as that of the endoscope device  1  of the first embodiment described above, and thus the description thereof will be omitted. 
     The light source unit illustrated in  FIG. 8  includes a plurality of first light sources (blue light source  651 B, green light source  651 G, red light source  651 R), a first mirror  652 B, a second mirror  652 G, a third mirror  652 R, a fourth mirror  653 , a pinhole  654 , a first reflection filter  655 , a first collimating lens  656 , a detection unit  657 , a second reflection filter  658 , a condenser lens  659 , a second emission unit  661 , and a second collimating lens  662 . In the fourth embodiment, the first light source corresponds to the first emission unit, and the first mirror  652 B, the second mirror  652 G, the third mirror  652 R, and the fourth mirror  653  correspond to a folded optical system, the first reflection filter  655  corresponds to an optical member, the second emission unit  661  corresponds to a second emission unit, the second reflection filter  658  corresponds to a combining member, and the condenser lens  659  corresponds to an illumination optical system. The first collimating lens  656  and the second collimating lens  662  are appropriately arranged in accordance with the optical system to be formed. 
     Each of the first light sources includes a laser light source and an optical fiber. Light (laser light) emitted from the laser light source is guided to one end of the optical fiber and emitted from the other end of the optical fiber. 
     The blue light source  651 B emits light (blue light) in a wavelength band of 450 nm or more and 500 nm or less. 
     The green light source  651 G emits light (green light) in a wavelength band of 490 nm or more and 600 nm or less. 
     The red light source  651 R emits light (red light) in a wavelength band of 590 nm or more and 750 nm less. 
     First mirror  652 B, second mirror  652 G, third mirror  652 R, and fourth mirror  653  reflect incident light. The first mirror  652 B reflects light in the wavelength band of 450 nm or more and 490 nm or less. The second mirror  652 G reflects light in the wavelength band of 490 nm or more and 590 nm or less and passes light in the wavelength band of 450 nm or more and 490 nm or less. The third mirror  652 R reflects light in the wavelength band of 590 nm or more and 750 nm or less and allows light in the wavelength band of 450 nm or more and 590 nm or less to pass. Beams of the light that has passed through the third mirror  652 R and the light that has been reflected by the third mirror  652 R are incident on the fourth mirror  653 , and the incident light is reflected by the fourth mirror  653  toward the pinhole  654 . The first mirror  652 B, the second mirror  652 G, the third mirror  652 R, and the fourth mirror  653  can alter the direction of the reflecting surface under the control of the light source controller  62 . For example, the angles of the first mirror  652 B, the second mirror  652 G, the third mirror  652 R, and the fourth mirror  653  are adjusted with respect to a preliminarily set axis. Adjustment of the angles of each of the mirrors uses a piezo motor, for example. 
     The light reflected by the fourth mirror  653  passes through the pinhole  654 . The pinhole  634  has an aperture having a preliminarily set diameter. 
     The first reflection filter  655  reflects light having a preliminarily set wavelength or less. In the fourth embodiment, the first reflection filter  655  reflects light of a part of the wavelength band of green light and allows light of other wavelength bands to pass. The first reflection filter  655  is provided downstream of the pinhole  654  and upstream of the second reflection filter  658  in the optical path. 
     The first collimating lens  656  includes one or more lenses, and collimates the light that has passed through the first reflection filter  655  and guides the collimated light to the second reflection filter  658 . 
     The detection unit  657  includes an optical sensor, receives light reflected by the first reflection filter  655 , and converts the light into an electrical signal. The electrical signal generated by the detection unit  657  is output to the light source controller  62 . 
     The second reflection filter  658  includes a half mirror, for example, and reflects half of the incident light, and allows the rest of the light to pass. The second reflection filter  658  combines the light emitted from the first light source and the light emitted from the second emission unit  661 . 
     The condenser lens  659  includes one or more lenses, and collects light that has passed through the first collimating lens  656  and light that has been emitted from the second emission unit  661  and has passed through the second reflection filter  658 , and supplies the collected light to the light guide  7 . 
     The second emission unit  661  includes: an LED light source  661   a  that emits blue light; and a yellow phosphor  661   b  that emits yellow (570 nm or more and 590 nm or less) fluorescence. The second emission unit  661  combines the blue light and yellow light to emit white light. The light emitted from the second emission unit  661  has a phase variation larger than the phase variation of the light emitted from the first light source (blue light source  651 B, green light source  651 G, red light source  651 R). 
     The second collimating lens  662  includes one or more lenses, and collimates the light emitted from the second emission unit  661  and guides the collimated light to the second reflection filter  658 . 
       FIG. 9  is a diagram illustrating a wavelength of light emitted from the light source device according to the fourth embodiment. In  FIG. 9 , the horizontal axis indicates the wavelength, and the vertical axis indicates the light intensity. 
     The light emitted from the first light source (blue light source  651 B, green light source  651 G, and red light source  651 R), specifically the light incident on the pinhole  654 , is intermittent light depending on the wavelength band of the light emitted by each of the light sources. For example,  FIG. 9  illustrates a waveform C 11  corresponding to the blue light emitted from the blue light source  651 B, a waveform C 12  corresponding to the green light emitted from the green light source  651 G, and a waveform C 13  corresponding to the red light emitted from the red light source  651 R. 
     The light emitted from the second emission unit  661 , specifically, the light incident on the second collimating lens  662 , is light in a broad wavelength band. For example,  FIG. 9  illustrates a waveform C 20  corresponding to white light emitted from the second emission unit  661 . 
     In a case where the first light source (blue light source  651 B, green light source  651 G, red light source  651 R) and the second emission unit  661  are driven simultaneously, the light produced by combining light beams of waveforms C 11 , C 12 , C 13 , and C 20  as illustrated in  FIG. 9  will be incident on the light guide  7 . The light emitted from the second emission unit  661  interpolates intermittent light emitted from the first light source. 
     In the light source unit described above, the light emitted from a first emission unit  651  passes through the first mirror  652 B, the second mirror  652 G, and the third mirror  652 R, reflected by the fourth mirror  653 , and then passes through the pinhole  654 . The light that has passed through the pinhole  654  is incident on the first reflection filter  655 . A part of the incident light passes through, and the rest of the light is reflected by the detection unit  657 . The light that has passed through the first reflection filter  655  passes through the first collimating lens  656  and the second reflection filter  658  and collected by the condenser lens  659 , so as to be incident on the light guide  7 . Meanwhile, the light incident on the detection unit  657  is converted into an electrical signal (signal value) indicating a value corresponding to the amount of light. 
     The light emitted from the second emission unit  661  passes through the second collimating lens  662  and the second reflection filter  658 , and collected by the condenser lens  659 , so as to be incident on the light guide  7 . 
     After receiving the electrical signal from the detection unit  657  in the infrared observation mode, the light source controller  62  determines the necessity of adjustment of the first mirror  652 B, the second mirror  652 G, the third mirror  652 R, and the fourth mirror  653  on the basis of the signal value and a preliminarily set threshold. For example, the light source controller  62  calculates a difference between the signal value and the threshold, and determines the necessity of adjustment of each of the mirrors in accordance with the difference. The threshold is a value set, for example, as a value corresponding to a maximum received amount of light predicted from the output of the first emission unit (laser light source), the amount of light passing through the pinhole  654 , and the reflection characteristics of the first reflection filter  655 . Specifically, the light source controller  62  changes the angle of each of the first mirror  652 B, the second mirror  652 G, the third mirror  652 R, and/or the fourth mirror  653  in accordance with the magnitude of the difference. 
     In the fourth embodiment described above, the first reflection filter  655  is used to cause a part of light guided from the first light source (blue light source  651 B, green light source  651 G, red light source  651 R) toward the condenser lens  659  to be incident on the detection unit  657 . Therefore, the amount of light emitted from the light source device  6  can be detected even during the use of the endoscope. 
     According to the fourth embodiment described above, the angle of each of the first mirror  652 B, the second mirror  652 G, the third mirror  652 R, and/or the fourth mirror  653  is controlled on the basis of the detection result of the detection unit  657 . This makes it possible to control the optical axis of the light so as to approach the ideal optical path to pass through, enabling adjustment so as to ensure the intensity as illumination light. 
     While the above-described fourth embodiment is an example of controlling the angles of the first mirror  652 B, the second mirror  652 G, the third mirror  652 R, and the fourth mirror  653  on the basis of the detection result of the detection unit  657 , it is allowable to configure to adjust the angle of at least one mirror. 
     In addition, the fourth embodiment described above is an example in which light having a part of the wavelength band of green light is incident on the detection unit  657  and then the detection unit  657  outputs an electrical signal based on this light. Alternatively, however, it is also allowable to have a configuration in which the first reflection filter  655  reflects 2% of the light that has passed through the pinhole  654  and causes the rest of the light to pass, and the detection unit  657  receives the part of the light including light of all wavelengths emitted by the first light source. 
     In addition, it is allowable to have a configuration in which the detection unit  657  includes an image sensor or the like that can receive light two-dimensionally so as to detect a two-dimensional light distribution for the light that has passed through the pinhole  654 . With a capability of the image sensor to receive light for each of colors, it is also possible to detect the light intensity or the like for each of the colors and individually control the first mirror  652 B, the second mirror  652 G, and the third mirror  652 R. 
     Fifth Embodiment 
     Next, a fifth embodiment will be described.  FIG. 10  is a view illustrating a configuration of a light source device included in an endoscope device according to the fifth embodiment. In the fifth embodiment, the configuration other than the light source unit  61  is the same as that of the endoscope device  1  of the first embodiment described above, and thus the description thereof will be omitted. 
     The light source unit illustrated in  FIG. 10  includes an emission unit  611 , a pinhole  614 , a reflection filter  615 , a condenser lens  616 , and a detection unit  617 . The light source unit according to the fifth embodiment is different from the light source unit  61  according to the first embodiment in that the first mirror  612  and the second mirror  613  are not provided. Other configurations are the same as those in the first embodiment. Hereinafter, portions different from the first embodiment will be described. 
     The emission unit  611  causes light to be incident on the pinhole  614 . Moreover, in the emission unit  611 , the direction of the emitting end of the optical fiber  611   b  is altered under the control of the light source controller  62 . In the emission unit  611 , the angle of the longitudinal axis of the optical fiber  611   b  is changed or the light emitting position is changed by moving the laser light source  611   a  and the optical fiber  611   b , under the control of the light source controller  62 , for example. 
     After receiving the electrical signal from the detection unit  617 , the light source controller  62  determines the necessity of adjustment of the emission unit  611  on the basis of the signal value and a preliminarily set threshold. For example, similarly to the first embodiment, the light source controller  62  calculates a difference between the signal value and the threshold and determines the necessity of adjustment of the emission unit  611  in accordance with the difference. When the light source controller  62  determines that adjustment of the emission unit  611  is necessary, the light source controller  62  controls the light emitting direction of the emission unit  611 . 
     In the fifth embodiment described above, the reflection filter  615  is used to allow a part of the light guided to the condenser lens  616  to be incident on the detection unit  617 , similarly to the first embodiment. This makes it possible to detect the amount of light emitted from the light source device  6  even during the use of the endoscope. 
     In addition, according to the fifth embodiment described above, the direction of the light emitted from the emission unit  611  is controlled on the basis of the detection result of the detection unit  617 . This makes it possible to control the optical axis of the light so as to approach the ideal optical path to pass through, enabling adjustment so as to ensure the intensity as illumination light. 
     While the above is description of the modes for carrying out the present disclosure, the present disclosure should not be limited by only the embodiments described above. In the above-described embodiment, the control device  5  performs signal processing or the like. Alternatively, however, signal processing or the like may also be performed on the camera head  9  side. 
     The first to fourth embodiments described above are an example in which the reflection filter that guides light to the detection unit reflects light. Alternatively, however, it is also allowable to have a configuration in which the light in a specific direction is directed to be reflected or pass through. 
     While the first, third, and fourth embodiments described above are an example in which a pinhole is provided to detect the intensity of light that has passed through the pinhole, it is also allowable to omit a pinhole as described in the second embodiment. Moreover, a pinhole may be provided in the second embodiment. 
     The first to fourth embodiments described above are an example of adjusting angles of mirrors. However, it is also allowable to alter the light emitting position and angle of the emission unit instead of adjusting angles of mirrors. 
     Moreover, the first to fourth embodiments described above are an example in which the light reflected by the mirror is detected by the detection unit and the light transmitted through the mirror is incident on the condenser lens. However, it is also allowable to have a configuration in which the light reflected by the mirror is incident on the condenser lens and the light transmitted through the mirror is detected by the detection unit. 
     As described above, the endoscope light source device according to the present disclosure has advantages in adjusting the amount of light emitted from the light source device with a simple configuration. 
     According to the present disclosure, it is possible to detect the amount of light emitted from the light source device even during the use of the medical device. 
     Although the disclosure has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.