Light source device, endoscope system, and light quantity control method

Abstract

This light source device comprises: a first light source; an optical sensor; a light amount information acquiring unit that acquires first information pertaining to a light amount of light received by the optical sensor; an optical member; an optical member moving unit that moves the optical member from a first position to a second position and inserts / removes the optical member into / from an optical path of light emitted from the first light source; a position information acquiring unit that acquires second information pertaining to the position of the optical member moving from the first position to the second position; and a control unit that outputs control information for controlling the first light source on the basis of the first information and the second information.

Description

[Technical field]

[0001] The present invention relates to a light source device, an endoscope system, and a light amount control method that appropriately control light from a plurality of semiconductor light emitting elements. [Background technology]

[0002] Conventionally, endoscopic devices equipped with an endoscope that is inserted into a body cavity or the like to observe a site to be examined or perform various treatments have been widely used. In such endoscopic devices, a light source device is employed to capture images of the inside of the body cavity. In recent years, some endoscopic devices use a light source device that employs a semiconductor light-emitting element such as an LED as a light source.

[0003] Such light source devices include a plurality of semiconductor light-emitting elements each emitting light of a different wavelength band, and emit a combined light obtained by appropriately combining the light of the plurality of colors according to an observation mode such as NBI (registered trademark) (narrow band light observation) or IR (infrared light observation). In order to obtain good observation and endoscopic images in an endoscope device, the light source device is controlled so as to keep the color balance (emission balance) of the emitted light constant when emitting a combined light of the plurality of colors. In the light source device, a light sensor is disposed adjacent to each LED, and when the amount of emitted light is changed, feedback control may be adopted in which the amount of emitted light from each LED is changed using the detection result of the light sensor to achieve a predetermined color balance.

[0004] For example, Japanese Patent No. 6072369 discloses a technique for measuring the amount of light after first increasing the amount of light when the amount of light is low, taking into consideration that an optical sensor cannot accurately detect brightness when the amount of light falls below a certain value.

[0005] Incidentally, not only light from a light source but also light reflected by various optical elements, for example, optical filters, enters an optical sensor. In order to obtain a good color balance, it is necessary to adjust the amount of light taking into consideration such reflected light. Japanese Patent No. 5393935 discloses a viewpoint that takes into consideration not only leakage light but also light reflected from an optical system when detecting the amount of light emitted from a light source.

[0006] However, the optical filter moves depending on the observation mode of the endoscope device, and the amount of reflected light from the optical filter that enters the optical sensor may change. In order to adjust the amount of light appropriate to the observation mode, it is necessary to perform control using the light amount detection value of the optical sensor measured after the movement of the optical filter is completed, which causes a problem that it takes a relatively long time to obtain the appropriate amount of light. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6072369 [Patent Document 2] Patent No. 5393935 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a light source device, an endoscope system, and a light amount control method that can shorten the time required for adjusting the light amount. DISCLOSURE OF THEINVENTION [Means for solving the problem]

[0009] A light source device according to one embodiment of the present invention includes a first light source, an optical sensor, a light amount information acquisition unit that acquires first information regarding the amount of light received by the optical sensor, an optical member, an optical member moving unit that moves the optical member from a first position to a second position and inserts or removes the optical member into or from the optical path of light emitted from the first light source, a position information acquisition unit that acquires second information regarding the position of the optical member while it is moving from the first position to the second position, and a control unit that outputs control information for controlling the first light source based on the first information and the second information.

[0010] In addition, a light source device according to another aspect of the present invention includes a light source, an optical sensor, a light amount information acquisition unit that acquires first information regarding the amount of light received by the optical sensor, an optical element, an optical element driving circuit that changes the optical element from a first characteristic to a second characteristic to limit the light emitted from the light source, a time information acquisition unit that acquires second information regarding the time from the start of a characteristic change of the optical element during the characteristic change from the first characteristic to the second characteristic, and a control unit that outputs control information for controlling the light source based on the first information and the second information.

[0011] An endoscope system according to one aspect of the present invention comprises: Inside A scope and The optical element includes a first light source, an optical sensor, a light amount information acquisition unit that acquires first information regarding the amount of light received by the optical sensor, an optical member, an optical member moving unit that moves the optical member from a first position to a second position and inserts or removes the optical member onto the optical path of light emitted from the first light source, a position information acquisition unit that acquires second information regarding the position of the optical member while it is moving from the first position to the second position, and a control unit that outputs control information for controlling the first light source based on the first information and the second information.

[0012] A light amount control method according to one aspect of the present invention is a light amount control method for controlling the amount of light of a light source by a processor, the method comprising: a light source emitting light; an optical sensor receiving the light; the processor acquiring first information on the amount of light received by the optical sensor; and determining a position of an optical member to be inserted or removed on an optical path of the light emitted from the light source. a position of the optical member during movement from a first position to a second position and outputs control information for controlling the light source based on the first information and the second information. Effect of the Invention

[0013] According to the present invention, there is an effect that the time required for adjusting the light amount can be shortened. [Brief description of the drawings]

[0014] [Figure 1] 1 is a configuration diagram showing a light source device according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is a configuration diagram showing an example of a light source device having a plurality of light sources. [Diagram 3] 1 is a schematic configuration diagram showing an example of an endoscope and an endoscope apparatus to which illumination light is supplied from a light source device according to the present embodiment. [Figure 4] 1 is a schematic configuration diagram showing an example of an endoscope and an endoscope apparatus to which illumination light is supplied from a light source device according to the present embodiment. [Diagram 5] 2 is an explanatory diagram showing an example of the configuration of an optical filter 5. FIG. [Figure 6] 1 is an explanatory diagram showing the relationship between the change in the positional relationship of the optical filter 5 (filter portion 5b) with respect to the light beam from the light source 2A when the observation mode is switched, and the filter reflected light, with the horizontal axis representing time. [Figure 7] 13 is a graph showing a change in the light amount detection value associated with filter movement, with the horizontal axis representing the amount of filter movement and the vertical axis representing the light amount detection value based on the output of the optical sensor 2S. [Figure 8] 13 is a flowchart showing an example of a case where light intensity adjustment is performed once when the observation mode is changed. [Figure 9] 11 is a time chart showing light amount adjustment when the observation mode is changed. [Figure 10] 13 is a flowchart showing an example of a case where light amount adjustment is performed multiple times when the observation mode is changed. [Figure 11] 11 is a time chart showing light amount adjustment when the observation mode is changed. [Figure 12] 1 is a diagram showing a second embodiment of the present invention. [Figure 13] 13 is a diagram showing modified example 1. [Figure 14] 13 is a diagram showing modified example 1. [Figure 15] 13 is a diagram showing modified example 2. [Figure 16] FIG. 11 is a configuration diagram showing a third embodiment of the present invention. [Figure 17]13 is a table illustrating light quantity correction values ​​stored in a memory 6 in the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0016] (First embodiment) FIG. 1 is a configuration diagram showing a light source device according to a first embodiment of the present invention. FIG. 2 is a configuration diagram showing an example of a light source device having a plurality of light sources. FIG. 3 and FIG. 4 are schematic configuration diagrams showing examples of an endoscope and an endoscope system to which illumination light is supplied from a light source device according to this embodiment. In the following description, it should be noted that the drawings based on the embodiments are schematic, and the relationship between the length and width of components (dimensional relationship), the length ratio of each part, etc. differ from the actual ones, and there may be cases where the dimensional relationship and ratio differ between multiple drawings. Also, illustration of some components may be omitted.

[0017] In this embodiment, the amount of light from the light source measured during the movement of the optical filter when switching the observation mode is corrected according to the amount of movement, making it possible to accurately determine the amount of light during the movement and shortening the time required to adjust the amount of light.

[0018] First, an endoscope and an endoscope system to which illumination light is supplied from a light source device according to this embodiment will be described with reference to FIGS. 3 and 4. FIG.

[0019] The endoscope system 20A in FIG. 3 includes a flexible endoscope 21, a light source device 10 that outputs illumination light, an image processing device 30 that performs imaging processing and the like, and a monitor 35 that displays an endoscopic image.

[0020] The endoscope 21 includes an insertion section 22, an operation section 23, a universal cord 24, and a scope connector 25. The insertion section 22 to be inserted into the subject is composed of a tip section 21a, a bending section 21b, and an elongated flexible section 21c. The bending section 21b, which is composed of a plurality of bending pieces, changes the direction of the tip section 21a in response to bending operation of the operation section 23. The flexible section 21c is formed of a flexible member. The base end of the insertion section 22 is connected to the operation section 23.

[0021] The operation unit 23 constitutes a gripping portion that is gripped by the surgeon, and is provided with a bending operation knob 23a for operating the bending portion 21b, etc. A universal cord 24 is connected to the operation unit 23. A scope connector 25 is provided on the base end side of the universal cord 24. The scope connector 25 is provided with an electric connector 25a connected to the image processing device 30, and a light receiving rod 25b connected to the light source device 10.

[0022] The illumination light from the light source device 10 is guided from the light receiving rod 25b to the tip 21a of the insertion section 22 via the universal cord 24 and a light guide inserted into the insertion section 22. An imaging device having an imaging element such as a CMOS sensor (not shown) is disposed in the tip 21a. The illumination light is irradiated from the tip 21a to a subject, and the reflected light from the subject forms an image on the imaging surface of the imaging device. The imaging device generates an imaging signal based on an optical image of the subject. This imaging signal is supplied to the image processing device 30 via the insertion section 22, the universal cord 24, and the electrical connector 25a. The image processing device 30 performs a predetermined image signal processing on the received imaging signal to generate a video signal. The image processing device 30 supplies the generated video signal to the monitor 35. As a result, an endoscopic image is displayed on the display screen of the monitor 35.

[0023] The endoscope system 20B in Fig. 4 includes a rigid endoscope 26, a light source device 10, an image processing device 30, and a monitor 35. The rigid endoscope 26 has a rigid insertion section 27, and an eyepiece section 28 is provided on the proximal end side of the insertion section 27. An observation optical system constituted by a relay lens (not shown) for transmitting a subject image and an illumination optical system constituted by a light guide (not shown) are provided inside the insertion section 27. A camera 29 is detachably provided in the eyepiece section 28.

[0024] The light source device 10 supplies illumination light to the endoscope 27 via a light guide cable 27a. The illumination light is irradiated onto the subject, and the light reflected from the subject is focused as an optical image of the subject on the imaging surface of the imaging element of the camera 29. The camera 29 supplies an imaging signal based on the optical image of the subject to the image processing device 30 via the imaging cable 29a. The image processing device 30 performs predetermined image signal processing on the received imaging signal to generate a video signal. The image processing device 30 supplies the generated video signal to the monitor 35, which displays an endoscopic image on the display screen of the monitor 35.

[0025] 1, a light source device 10 includes a control circuit 1, a light source 2A, a light source driving unit 3, an optical sensor 2S, and a memory 6. The control circuit 1 as a control unit controls the entire light source device 10. The control circuit 1 may be configured by a processor using a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array). The control circuit 1 may operate according to a program stored in a memory (not shown) to control each unit, or may realize some or all of the functions by a hardware electronic circuit.

[0026] The light source driving unit 3 is controlled by the light source control unit 1a in the control circuit 1 to control the light emission of the light source 2A. The light source 2A is driven by the light source driving unit 3 to emit light. As the light source 2A, various light emitting elements such as LEDs (Light Emitting Diodes), LDs (Laser Diodes), and organic ELs (Electro Luminescence) can be used. A mixture of multiple types of light emitting elements may also be used as the light source 2A. The light emission amount of the light source 2A is controlled by the light source driving unit 3. The light from the light source 2A is emitted via a lens or the like (not shown).

[0027] In FIG. 1, an optical filter 5, which is an optical member, is disposed on the light beam (bold line) of the light emitted from the light source 2A. The optical filter 5 includes a filter section 5a for normal light observation by an endoscope device, for example, and a filter section 5b for special light observation such as NBI (narrow band observation) or IR (infrared observation). The optical filter 5 is driven by a drive circuit 7 and is disposed movably so that the filter section 5a or the filter section 5b is interposed on the light beam. The filter section 5a may be formed of, for example, an aperture that passes white light from the light source 2A as it is. The filter section 5b may have a filter that attenuates a component of a predetermined color light. The diameter of the light beam from the light source 2A is smaller than the diameters of the filter sections 5a and 5b.

[0028] Fig. 5 is an explanatory diagram showing an example of the configuration of the optical filter 5. The left side of Fig. 5 shows the planar shape of the optical filter 5 seen in a direction parallel to the direction of the light beam, and the right side of Fig. 5 shows the side shape of the optical filter 5 seen in a direction perpendicular to the direction of the light beam. The optical filter 5 has a disk-shaped rotating filter frame 5c that is an optical element holding member. The rotating filter frame 5c has, for example, a filter section 5a formed by an aperture provided in the rotating filter frame 5c, and a filter section 5b formed by a filter that limits (absorbs) the transmission of a predetermined wavelength band for special light observation.

[0029] The center of the rotating filter frame 5c is attached to the rotation axis of a stepping motor 5d, and the rotating filter frame 5c can be rotated by the stepping motor 5d in a plane perpendicular to the direction of the light beam. A driving circuit 7 serving as an optical member moving unit may be controlled by the control circuit 1 to drive the stepping motor 5d to rotate the rotating filter frame 5c. The rotation of the rotating filter frame 5c causes the filter unit 5a or the filter unit 5b to be positioned on the light beam.

[0030] In FIG. 5, the rotating filter frame 5c is configured to rotate 180 degrees to switch between filter section 5a and filter section 5b that are present on the light beam; however, the rotation angle of the rotating filter frame 5c that switches between filter section 5a and filter section 5b on the light beam can be set as appropriate by appropriately changing the arrangement of filter section 5a and filter section 5b.

[0031] 5 shows an example in which the optical filter 5 is configured in a disk shape and the filter portions 5a and 5b are moved by rotating the rotating filter frame 5c, but the optical filter 5 itself may be moved relative to the light beam to place the filter portion 5a or 5b on the light beam. In addition, in Fig. 1 and Fig. 2, an example is shown in which the optical filter 5 is moved to place the filter portion 5a or the filter portion 5b on the light beam, but the light path of the light beam may be changed using a mirror or the like so that the light beam passes through the filter portion 5a or 5b.

[0032] An optical sensor 2S is provided near the light source 2A. The optical sensor 2S detects the amount of incident light and outputs the detection output to the light amount acquisition unit 1b of the control circuit 1. The light amount acquisition unit 1b, which serves as a light amount information acquisition unit, detects the light amount value generated by the light source 2A based on the detection output of the optical sensor 2S. The light source control unit 1a of the control circuit 1 controls the light source driving unit 3 based on the light amount detection value by the light amount acquisition unit 1b, thereby performing control so that a desired amount of light is generated from the light source 2A.

[0033] Fig. 2 corresponds to a case where there are a plurality of light sources 2A. Although Fig. 2 shows an example in which LEDs of five colors are used, LEDs of four or less colors, or LEDs of six or more colors may be used.

[0034] In Fig. 2, the light source device 10 has a control circuit 1 similar to that in Fig. 1. The light source device 10 also has, in an optical system 2, a violet LED (hereinafter referred to as V-LED) 2LV, a blue LED (hereinafter referred to as B-LED) 2LB, a green LED (hereinafter referred to as G-LED) 2LG, an amber LED (hereinafter referred to as A-LED) 2LA, and a red LED (hereinafter referred to as R-LED) 2LR (hereinafter, when it is not necessary to distinguish between these LEDs, they will be collectively referred to as LED 2L). The V-LED 2LV emits violet light, the B-LED 2LB emits blue light, the G-LED 2LG emits green light, the A-LED 2LA emits amber light, and the R-LED 2LR emits red light.

[0035] In the optical system 2, a lens 2ZB and a dichroic filter 2MB are disposed on the optical path of the light emitted from the LED 2LB, a lens 2ZG and a dichroic filter 2MG are disposed on the optical path of the light emitted from the LED 2LG, a lens 2ZA and a dichroic filter 2MA are disposed on the optical path of the light emitted from the LED 2LA, and a lens 2ZR and a dichroic filter 2MR are disposed on the optical path of the light emitted from the LED 2LR. A lens 2ZV and dichroic filters 2MB, 2MG, 2MA, and 2MR are disposed on the optical path of the light emitted from the LED 2LV.

[0036] Lenses 2ZV, 2ZB, 2ZG, 2ZA, and 2ZR (hereinafter, when there is no need to distinguish between these lenses, they will be referred to as lens 2Z) respectively convert the emitted light from V-LED2LV, B-LED2LB, G-LED2LG, A-LED2LA, and R-LED2LR into approximately parallel light and emit it.

[0037] The dichroic filter 2MB transmits the light emitted from the lens 2ZV and reflects the light emitted from the lens 2ZB. The dichroic filter 2MG transmits the light from the dichroic filter 2MB and reflects the light emitted from the lens 2ZG. The dichroic filter 2MA transmits the light from the dichroic filter 2MG and reflects the light emitted from the lens 2ZA. The dichroic filter 2MR transmits the light from the dichroic filter 2MA and reflects the light emitted from the lens 2ZR.

[0038] In this way, the outputs of the LEDs 2L are synthesized (combined) by the dichroic filters 2MB, 2MG, 2MA, and 2MR (hereinafter, when there is no need to distinguish between these dichroic filters, they will be collectively referred to as the dichroic filter 2M). The synthesized light from the dichroic filter 2MR passes through the optical filter 5 and is outputted via the lens 2LZ. The synthesized light from the lens 2LZ is supplied to the flexible endoscope 21, the rigid endoscope 26, etc. as illumination light.

[0039] In addition, Figure 2 shows an example in which the drive circuit 7 is controlled by the control circuit 1 to insert or remove the optical filter 5 onto the optical path of the light emitted from the dichroic filter 2MR, thereby switching whether or not the filter section 5b is present on the light beam of the light emitted from the dichroic filter 2MR.

[0040] The light source device 10 includes a violet driver (hereinafter referred to as a V driver) 3DV, a blue driver (hereinafter referred to as a B driver) 3DB, a green driver (hereinafter referred to as a G driver) 3DG, an amber driver (hereinafter referred to as an A driver) 3DA, and a red driver (hereinafter referred to as an R driver) 3DR (hereinafter, when it is not necessary to distinguish between these drivers, they are collectively referred to as the driver 3D). The V driver 3DV drives the V-LED2LV, the B driver 3DB drives the B-LED2LB, the G driver 3DG drives the G-LED2LG, the A driver 3DA drives the A-LED2LA, and the R driver 3DR drives the R-LED2LR. For example, each driver 3D may control the amount of light emitted by each LED2L by current driving that changes the amount of current supplied to each LED2L, or PWM driving that changes the pulse width of the driving pulse.

[0041] In the vicinity of each LED2L configured in the optical system 2, optical sensors 2SEV, 2SEB, 2SEG, 2SEA, and 2SER (hereinafter, when it is not necessary to distinguish between these optical sensors, they will be collectively referred to as optical sensor 2SE) are provided at positions shifted from the optical path of the emitted light of each LED2L. A beam splitter (not shown) may be provided between each LED2L and the corresponding lens 2Z to make the light from each LED2L incident on the corresponding optical sensor 2SE. As shown by the arrows in FIG. 2, the optical sensors 2SEV, 2SEB, 2SEG, 2SEA, and 2SER mainly detect the amount of illumination light from the V-LED2LV, B-LED2LB, G-LED2LG, A-LED2LA, and R-LED2LR, and output the detection output to the light amount detection circuit 4.

[0042] The light amount detection circuit 4 corresponds to the light amount acquisition unit 1b in FIG. 1, and detects the light amount value of the light generated by each LED 2L based on the detection output of the optical sensor 2SE. The light amount detection circuit 4 outputs the light amount detection value of the light generated by each LED 2L to the control circuit 1. The control circuit 1 controls the light amount of each LED 2L individually based on the output of the light amount detection circuit 4. As a result, illumination light with a desired light amount and a desired color balance is emitted from the lens 2LZ.

[0043] That is, in the light source device 10 of FIG. 2, the light amount adjustment is performed by adjusting the amount of light emitted from each LED 2L. This light amount adjustment adjusts the amount of light of the combined light from the lens 2LZ, and also performs color balance adjustment to adjust the ratio of the amount of light emitted by each LED 2L (light amount ratio). The control circuit 1 controls the amount of light of each LED 2L while maintaining the ratio of the amount of light emitted by each LED 2L (light amount ratio) so as to obtain an optimal color balance, based on, for example, brightness control information from an endoscope system. For example, the control circuit 1 obtains dimming information corresponding to the light amount value of G-LED2LG to be set according to the brightness control information from the endoscope system, and obtains dimming information for the other V-LED2LV, B-LED2LB, A-LED2LA, and R-LED2LR so as to achieve a predetermined light amount ratio according to the light amount value of G-LED2LG.

[0044] (Reflected light from an optical filter) 1 and 2, not only leakage light of light generated by the light source 2A or each LED 2L but also reflected light from the optical filter 5 enters the optical sensor 2S or each optical sensor 2SE. That is, reflected light obtained when light from the light source 2A is reflected by the optical filter 5 enters the optical sensor 2S, and reflected light obtained when light from each LED 2L is reflected by the optical filter 5 (hereinafter, reflected light from the optical filter 5 is referred to as filter reflected light) enters each optical sensor 2SE.

[0045] In the following, for the sake of simplicity, the single light source in FIG. 1 will be taken as an example for explanation. The amount of light reflected by the filter changes depending on the position of the filter sections 5a and 5b of the optical filter 5 relative to the light beam from the light source 2A. For example, when the state where the filter section 5a is on the light beam and the state where the filter section 5b is on the light beam are switched due to a change in the observation mode, the amount of light reflected by the filter that enters the optical sensor 2S differs. For this reason, as described above, in the past, in order to accurately control the amount of light from the light source 2A, there was a problem that the light amount control could not be performed until the movement of the optical filter 5 accompanying the change in the observation mode was completed.

[0046] Therefore, in this embodiment, the amount of light emitted from the light source 2A can be accurately detected even while the optical filter 5 is moving, thereby shortening the time required to adjust the amount of light, and making it possible to obtain a good observation image (endoscopic image) immediately after switching the observation mode.

[0047] Fig. 6 is an explanatory diagram showing the change in the positional relationship of the optical filter 5 (filter section 5b) with respect to the light beam from the light source 2A when switching the observation mode, and the relationship with the filter reflected light, with the horizontal axis representing the time. Fig. 7 is a graph showing the change in the light intensity detection value associated with the filter movement, with the horizontal axis representing the filter movement amount and the vertical axis representing the light intensity detection value based on the output of the optical sensor 2S.

[0048] The arrows in FIG. 6 indicate the light beam that proceeds without being blocked by the filter portion 5b. FIG. 6 shows how the optical filter 5 moves between times t0 and t4, and the filter portion 5b gradually comes to be present on the light beam. The percentages in FIG. 6 indicate the ratio of the area of ​​the light beam blocked by the filter portion 5b (hereinafter referred to as the reflection area ratio), that is, the degree of insertion of the filter portion 5b on the light beam. The reflection area ratio of 0% at time t0 in FIG. 6 indicates the state in which the filter portion 5b does not come to be present on the light beam, and the reflection area ratio of 100% at time t4 indicates the state in which the filter portion 5b comes to be present over the entire light beam. Similarly, the reflection area ratios of 25%, 50%, and 75% at times t1 to t3 indicate the states in which the filter portion 5b comes to be present in 25%, 50%, and 75% of the light beam, respectively.

[0049] The filter section 5b absorbs light and limits the transmission of the light. The light whose transmission is limited is reflected and becomes filter reflected light. That is, there is no filter reflected light at time t0. If the amount of filter reflected light at time t4 is 100%, the amounts of filter reflected light at times t1 to t3 are considered to be approximately 25%, 50%, and 75%, respectively.

[0050] The reflection area ratio of the filter portion 5b is a value indicating what percentage of the light flux is reflected by the filter portion 5b, and this reflection area ratio is uniquely determined by the position of the optical filter 5. Therefore, by correcting the light intensity detection value based on the output of the optical sensor 2S using the position information of the optical filter 5 corresponding to the reflection area ratio, i.e., the degree of insertion of the filter portion 5b onto the light flux, it is possible to accurately calculate the current value of the light intensity value of the light emitted from the light source 2A (hereinafter referred to as the light source light intensity value) even during the movement of the optical filter 5. In addition, if the time required for the movement of the optical filter 5 is known, it is also possible to obtain the light source light intensity value after the movement of the optical filter 5 is completed by correcting the current light intensity detection value based on the output of the optical sensor 2S based on the position information of the optical filter 5.

[0051] (Calculation of light source light intensity value when optical filter is moved) Fig. 7 shows the relationship between the reflection area ratio (filter movement amount) and the light amount detection value based on the output of the optical sensor 2S. From the characteristics shown in Fig. 7, it can be seen that the light source light amount value can be calculated even while the optical filter 5 is moving.

[0052] In the rotary optical filter 5 shown in FIG. 5, it is assumed that X% of the light flux is irradiated onto the filter portion 5b. In this case, in addition to the filter reflected light corresponding to X% of the light flux, the absorbed components in the region of (100-X)% of the light flux are reflected by the rotary filter frame 5c to become the filter reflected light. A predetermined correction value (hereinafter, referred to as a reflection correction value) that takes into account the reflection by the filter portion 5b and the rotary filter frame 5c is multiplied by the light quantity detection value based on the output of the optical sensor 2S to obtain the light source light quantity value. Furthermore, in this embodiment, the reflection area ratio, i.e., information on the movement amount of the optical filter 5, is used to enable accurate calculation of the light source light quantity value during the movement of the optical filter 5.

[0053] In FIG. 1, the control circuit 1 includes an optical filter position acquisition unit 1c. The optical filter position acquisition unit 1c, which serves as a position information acquisition unit, detects the position of the optical filter 5 using various known methods to acquire position information. For example, the optical filter position acquisition unit 1c may detect the position of the optical filter 5 using the output of various sensors that detect the rotation of the rotating filter frame 5c. The optical filter position acquisition unit 1c may also detect the position of the optical filter 5 based on the number of drive pulses (number of steps) by a drive circuit 7 that drives a stepping motor 5d. The control circuit 1 calculates the light source light amount value during the movement of the optical filter 5 based on the light amount detection value obtained by the light amount acquisition unit 1b and the position information obtained by the optical filter position acquisition unit 1c.

[0054] The light source light amount value during the movement of the optical filter 5 can be calculated by the following formula (1): The position information in formula (1) is a value indicating the reflection area ratio. Light source light quantity value = Light quantity detection value based on optical sensor output × Position information of optical filter 5 × Reflection correction value … (1) The control circuit 1 may calculate the light source light quantity value in real time based on the above formula (1) every time the position of the optical filter 5 changes. The control circuit 1 may also store in advance in the memory 6 the position information x reflection correction value (hereinafter, this value will be referred to as the light quantity correction value) of formula (1) for each position of the optical filter 5. In this case, the control circuit 1 can calculate the light source light quantity value by reading out the light quantity correction value corresponding to the position of the optical filter 5 from the memory 6 and multiplying the light quantity detection value by the read out light quantity correction value.

[0055] In this embodiment, the light source light quantity value of each LED 2L is calculated based on the above formula (1) or obtained using information stored in the memory 6. The control circuit 1 obtains an optimal color balance by controlling each driver 3D based on the obtained dimming information for each LED 2L.

[0056] (Statistical processing) In the above description, the light amount may be adjusted using the light source light amount value during the movement of the optical filter 5, or the light amount may be adjusted by estimating the light source light amount value after the movement is completed from the light source light amount value during the movement of the optical filter 5. Furthermore, the light amount may be adjusted by statistical processing of the light source light amount value obtained during the movement.

[0057] For example, a plurality of light intensity correction values ​​are obtained in advance for the movement of the optical filter 5 from 0% to 100%. The light source light intensity values ​​obtained using these plurality of light intensity correction values ​​are statistically processed to control the light source 2A and LED 2L. For example, for the R-LED 2LR, the light source light intensity values ​​when the filter movement amounts are 25%, 50%, and 75% are respectively obtained as a, b, and c. In this case, after the movement of the optical filter 5 is completed, the arithmetic mean (a+b+c) / 3 and the geometric mean (a 2 +b 2 +c 2 ) 1 / 2 Alternatively, the amount of power supply to the R-LED2LR may be calculated by using the most frequent value or the median value of (a, b, c) as the light source light amount value.

[0058] (action) Next, the operation of the embodiment configured in this manner will be described with reference to Figs. 8 to 11. Fig. 8 is a flow chart showing an example of a case where light intensity adjustment is performed once when the observation mode is changed, and Fig. 10 is a flow chart showing an example of a case where light intensity adjustment is performed multiple times when the observation mode is changed. Figs. 9 and 11 are time charts showing light intensity adjustment when the observation mode is changed. Note that the following operation will be described using the example of Fig. 2 having multiple light sources, but the same operation as the example of Fig. 2 is performed in the example of Fig. 1 showing a single light source. As described above, color balance adjustment is also performed in the light intensity adjustment of multiple light sources.

[0059] (High light to high light) Now, assume that the observation mode is switched when the light intensity is relatively high (hereinafter, referred to as high light intensity). For example, assume that the observation mode is switched from the white light observation mode using the filter unit 5a to the NBI observation mode using the filter unit 5b. Figs. 8 and 9 show the switching in the case of high light intensity. The control circuit 1 starts driving the rotating filter frame 5c at S1 in Fig. 8. Fig. 9 shows the change in the rotating filter frame 5c in the upper part, the dimming control in the comparative example in the middle part, and the dimming control in the first embodiment in the lower part. As shown in Fig. 9, when the white light observation mode (WLI) is switched to the NBI observation mode (NBI), the ratio of the filter unit 5b intervening in the light flux from the dichroic filter 2MR changes from 0% to 100% (i.e., the optical filter 5 moves). The time required for this movement is time TFR.

[0060] 9, after the movement of the optical filter is completed, the light intensity value of each LED is obtained and color balance adjustment is performed. If the time required for measuring the light intensity value and adjusting the color balance is α, in the comparative example, it takes time TFR+α to switch the observation mode.

[0061] In contrast, in this embodiment, the light quantity value is calculated immediately after the movement of the optical filter 5 is started to switch the observation mode. That is, the optical filter position acquisition unit 1c of the control circuit 1 detects the position of the rotating filter frame 5c and obtains position information. The control circuit 1 reads out the light quantity correction value from the memory 6 using this position information, for example (S2). Each optical sensor 2SE detects the amount of light incident thereon and outputs the detection output to the light quantity acquisition unit 1b of the control circuit 1. The light quantity acquisition unit 1b obtains the light quantity detection value based on the detection output of each optical sensor 2SE (S3). The control circuit 1 obtains the light source light quantity value corresponding to the current position of the optical filter 5 for each LED 2L by multiplying the light quantity detection value by the light quantity correction value (S4). The control circuit 1 may also estimate the light source light quantity value after the movement of the optical filter 5 is completed from the current light source light quantity value.

[0062] The light source control unit 1a of the control circuit 1 generates a control signal for setting the light emission amount of each LED 2L to a specified light emission amount based on the calculated current light source light amount value of each LED 2L or the light source light amount value after the completion of the movement of the optical filter 5. This control signal is supplied to each driver 3D, and the driver 3D drives each LED 2L so that the desired amount of light is generated from each LED 2L (S5).

[0063] The control circuit 1 determines whether or not the movement of the optical filter 5 is complete (S6). If the movement of the optical filter 5 is not complete (NO judgment in S6), the movement is continued, and if the movement of the optical filter 5 is complete (YES judgment in S6), the rotation of the rotating filter frame 5c is stopped (S7).

[0064] As shown in FIG. 9, in this embodiment, adjustment of the light source light intensity value and color balance is started immediately after the observation mode switching begins and is performed in a time shorter than the time TFR, so that imaging with appropriate color balance becomes possible as soon as the movement of the optical filter 5 is completed.

[0065] (low to very low light) Now, assume that the observation mode is switched when the amount of light emitted by the LED 2L is below a certain level where the light sensor 2SE cannot accurately detect the brightness. For example, the amount of light may be weak when the tip of the endoscope is brought close to the subject. Figures 10 and 11 show the switching in this case. In Figure 10, the same steps as in Figure 8 are assigned the same reference numerals and the description will be omitted.

[0066] In a state of weak light intensity, the optical sensor 2SE cannot detect the light intensity accurately, so the control circuit 1 controls to once increase the light intensity to a high light intensity (S11) and then measures the light intensity. Now, assume that the observation mode is switched from the white light observation mode using the filter unit 5a to the NBI observation mode using the filter unit 5b. When switching the observation mode, the control circuit 1 switches the weak light intensity to a high light intensity, as shown in FIG. 11. In this state, the control circuit 1 starts driving the rotating filter frame 5c in S1 of FIG. 9.

[0067] 11 shows the change in the rotating filter frame 5c in the top row, the second and third rows show the dimming control in the comparative example, and the fourth and fifth rows show the dimming control in the embodiment. As shown in Fig. 11, in order to switch from the white light observation mode (WLI) to the NBI observation mode (NBI), the time required for the filter unit 5b to move onto the light beam from the dichroic filter 2MR and change from a state with a reflection area ratio of 0% to a state with a reflection area ratio of 100% is time TFR.

[0068] In the comparative example shown in the second row of Fig. 11, the light intensity value of each LED is obtained while the optical filter is moving, and color balance adjustment is performed. After the movement of the optical filter is completed, convergence control is performed to return the high light intensity to a weak light intensity. If the time required to return (converge) the high light intensity to a weak light intensity is β, the time required to switch the observation mode is the time TFR+β. Because the light intensity value of each LED is obtained while the optical filter is moving, the obtained light intensity value is inaccurate due to the influence of light reflected by the filter, and as a result, the color balance has an error.

[0069] In the comparative example shown in the second row of Fig. 11, color balance adjustment is performed even after the movement of the optical filter is completed. After the color balance adjustment, control is performed to return the high light intensity to the weak light intensity. In this case, there is no color balance error, but the time required to switch the observation mode is the time TFR + α + β.

[0070] In contrast, in this embodiment, the light source light intensity value is calculated immediately after starting the movement of the optical filter 5 to switch the observation mode (S2 to S4). In this way, the current light source light intensity value or the light source light intensity value after the movement of the optical filter 5 is completed is obtained. The example in the fourth row of FIG. 11 corresponds to the flow in FIG. 8, and color balance adjustment is performed only once. After the color balance adjustment is completed, control is performed to return the high light intensity to a weak light intensity (S12). As a result, as shown in the fourth row of FIG. 11, the time required to switch the observation mode can be shortened to time TFR without generating a color balance error.

[0071] Moreover, the example in the fifth row of Fig. 11 corresponds to the flow in Fig. 9. In this case, if it is determined in S6 that the movement of the optical filter 5 is not complete (NO determination in S6), the processes of S2 to S5 are repeated. That is, the calculation of the light source light intensity value and the color balance adjustment are repeated, and a more accurate color balance adjustment is performed. In this case, the time required to switch the observation mode is the time TFR+β.

[0072] In this manner, in this embodiment, by making it possible to accurately detect the amount of light emitted from the light source 2A even while the optical filter 5 is moving, it is possible to shorten the time required to adjust the amount of light, and to obtain a good observation image (endoscopic image) immediately after switching the observation mode.

[0073] In the above description, it has been explained that after the transition of the observation mode, observation is performed by implementing light intensity control using the light source light intensity value determined during the movement of the optical filter 5. Furthermore, during this observation, the light source 2A may be caused to emit light at a normal light intensity, not weak light, and the light source light intensity value may be remeasured using a light intensity correction value corresponding to a movement amount of 100%, and thereafter, the remeasured light source light intensity value may be used to perform light intensity control and continue the observation.

[0074] Second Embodiment FIG. 12 is a table showing a second embodiment of the present invention. The second embodiment shows an example of a specific method for determining a light intensity correction value. The hardware configuration of this embodiment is the same as that of the first embodiment. Furthermore, in this embodiment, the calculation formula for the current light source light intensity value, the estimation of the light source light intensity value after switching of the observation mode, the statistical processing of the light source light intensity value, and the methods of light intensity adjustment and color balance adjustment are also the same as those of the first embodiment.

[0075] Fig. 12 explains the light quantity correction values ​​stored in the memory 6. In the figure, P1 indicates a light quantity value obtained from the measurement result of each optical sensor 2SE when the filter unit 5b is not interposed on the light flux of the outgoing light of the dichroic filter 2MR, and P2 indicates a light quantity value obtained from the measurement result of each optical sensor 2SE when the filter unit 5b is interposed on the light flux of the outgoing light of the dichroic filter 2MR. The example of Fig. 12 shows P2 when P1 is set to 1 for each movement amount.

[0076] The amount of movement (%) in Fig. 12 is a value indicating what percentage of the light flux the filter section 5b is involved in. When the amount of movement is 0%, P1 = P2 = 1, and the light intensity correction value γ is 1. As the amount of movement increases, the amount of light reflected by the filter increases, and P2 becomes larger. The light intensity correction value γ becomes smaller as the amount of movement increases.

[0077] The light quantity correction value γ is calculated as the ratio of the light quantity value P1 when the filter is not interposed to the light quantity value P2 when the filter is interposed, and is expressed as γ=P1 / P2. The control circuit 1 calculates the light quantity value P1 obtained from the measurement result of each optical sensor 2SE without interposing the filter unit 5b. The control circuit 1 moves the optical filter 5 without changing the control for each optical sensor 2SE, and calculates the light quantity value P2 obtained from the measurement result of each optical sensor 2SE while changing the amount of movement. The control circuit 1 calculates the light quantity correction value γ by calculating P1 / P2. The control circuit 1 associates the amount of movement with the light quantity correction value γ and stores it in the memory 6, as shown in FIG. 12.

[0078] When switching the observation mode, the control circuit 1 obtains the movement amount of the optical filter 5. The control circuit 1 reads out the light intensity correction value from the memory 6 using the obtained movement amount. The control circuit 1 obtains the light intensity detection value based on the detection output of each optical sensor 2SE, and obtains the light source light intensity value corresponding to the current position of the optical filter 5 for each LED 2L by multiplying the light intensity detection value by the light intensity correction value. The control circuit 1 may also estimate the light source light intensity value after the movement of the optical filter 5 is completed from the current light source light intensity value. The control circuit 1 may also obtain the light source light intensity value after the movement of the optical filter 5 is completed by the above-mentioned statistical method.

[0079] The control circuit 1 controls the light intensity of each LED 2L based on the obtained light source light intensity value, thereby enabling imaging with accurate color balance immediately after the optical filter 5 has been moved.

[0080] The other configurations and operations are similar to those of the first embodiment.

[0081] (Variation 1) 13 and 14 are diagrams showing Modification 1. In FIG. 12, the light intensity correction value γ is calculated based on the light intensity values ​​P1 and P2. However, it is also possible that the light intensity correction value γ depends on the light emission intensity of the LED. FIG. 13 takes this case into consideration, and the light intensity correction value γ is calculated by γ=(P1 / P2)×δ. The amount of power supplied to each LED 2L shown in FIG. 13 and the value of the correction value δ are stored in memory 6 in correspondence with each other.

[0082] 13, when the amount of power supplied to LED2L is greater than 2 W and equal to or less than 3 W, δ=1.9, when the amount of power supplied to LED2L is greater than 1 W and equal to or less than 2 W, δ=1.2, and when the amount of power supplied to LED2L is greater than 0 W and equal to or less than 1 W, δ=1. In other words, the greater the amount of power supplied to LED2L, the greater the light source light intensity value that is calculated.

[0083] 14 also takes into consideration that the light quantity correction value γ depends on the amount of light detected by the optical sensor 2SE. In this case, the light quantity correction value γ is calculated by γ=(P1 / P2)×δ. The amount of light detected by each optical sensor 2SE shown in FIG. 14 and the correction value δ are stored in the memory 6 in correspondence with each other.

[0084] 14, when the amount of detection by the optical sensor 2SE is greater than 2 and less than or equal to 3, δ=1.9, when the amount of detection by the optical sensor 2SE is greater than 1 and less than or equal to 2, δ=1.2, and when the amount of detection by the optical sensor 2SE is greater than 0 and less than or equal to 1, δ=1. In other words, the greater the amount of detection by the optical sensor 2SE, the greater the light source light amount value that is obtained.

[0085] The other configurations and operations are similar to those of the second embodiment.

[0086] (Variation 2) Fig. 15 is a chart showing Modification 2. Although not mentioned in the explanations of Figs. 12 to 14, it is considered that the filter reflected light mainly contains a specific wavelength component according to the characteristics of the filter unit 5b. For example, the filter unit 5b used in the NBI observation mode may have a characteristic of absorbing green light and violet light, and it is considered that the filter reflected light of these colors of light is obtained.

[0087] Therefore, these color lights may be considered as the light intensity correction value γ. Figure 15 shows the light intensity correction value in this case. In the example of Figure 15, the light intensity correction values ​​for G-LED2LG at the movement amounts of 0%, 25%, 50%, 75% and 100% are represented as γNG0%, γNG25%, γNG50%, γNG75% and γNG100%, respectively. Also, the light intensity correction values ​​for V-LED2LV at the movement amounts of 0%, 25%, 50%, 75% and 100% are represented as γNG0%, γNG25%, γNG50%, γNG75% and γNG100%, respectively.

[0088] For R-LED2LR, B-LED2LB, and A-LED2LA, it is not necessary to consider the influence of the filter reflected light. Also, the filter unit 5a used in the white light imaging (WLI) mode does not have the property of absorbing light (no filter). Even in the narrow band imaging (NBI) mode, the light amount cannot be measured for weak light, and the light amount correction value is not set. The information shown in FIG. 15 is stored in the memory 6.

[0089] The control circuit 1 obtains the light source light intensity value of the G-LED2LG by multiplying the light intensity detection value based on the detection output of the optical sensor 2SE by the light intensity correction value γNG0% to γNG100% corresponding to the amount of movement. The control circuit 1 obtains the light source light intensity value of the V-LED2LV by multiplying the light intensity detection value based on the detection output of the optical sensor 2SEV by the light intensity correction value γNV0% to γNV100% corresponding to the amount of movement. For the R-LED2LR, B-LED2LB, and A-LED2LA, the light intensity value based on the detection outputs of the optical sensor 2SER, the optical sensor 2SEB, and the optical sensor 2SEA is the light source light intensity value.

[0090] The method of controlling each LED 2L using the obtained light source light amount value is the same as in the second embodiment. Other configurations and operations are also similar to those of the second embodiment.

[0091] (Third embodiment) Fig. 16 is a configuration diagram showing a third embodiment of the present invention. In Fig. 16, the same components as those in Fig. 1 are given the same reference numerals and their explanations are omitted. A light source device 10A in this embodiment differs from the light source devices 10 in the first and second embodiments in that an electro-optical filter 5A is used instead of the optical filter 5.

[0092] In the above first and second embodiments, the observation mode is switched by physically moving the optical filter 5, but in this embodiment, the observation mode can be switched by changing the characteristics of the electro-optic filter 5A, which is an optical element. The electro-optic filter 5A is electrically controlled by a driving circuit 7A, and its optical characteristics change. For example, a filter that can increase or decrease the wavelength absorptance according to the applied voltage by the Franz-Keldysh effect may be used as the electro-optic filter 5A.

[0093] The control circuit 1A controls the entire light source device 10A. The control circuit 1A may be configured by a processor using a CPU, an FPGA, or the like. The control circuit 1A may operate according to a program stored in a memory (not shown) to control each part, or may realize some or all of the functions by a hardware electronic circuit. The control circuit 1A has the same functions as the control circuit 1 in the first and second embodiments. The control circuit 1A has a time information acquisition unit that acquires the elapsed time in the characteristic change of the electro-optical filter 5A, instead of the optical filter position acquisition unit 1c in FIG. 1.

[0094] The control circuit 1A controls the driving circuit 7A to switch the characteristics of the electro-optical filter 5A between characteristics suitable for white light observation and characteristics suitable for special light observation. The electro-optical filter 5A also requires a certain time for the characteristics to change due to a change in the applied voltage. Therefore, the switching of the observation mode is completed when a certain time has passed from the timing when the driving circuit 7A starts changing the applied voltage for switching the observation mode. From the start of switching the observation mode to the completion of the switching, the characteristics of the electro-optical filter 5A gradually change, and the amount of light reflected by the filter also changes during this period. Therefore, even when the electro-optical filter 5A is used, by acquiring the light source light amount value during the change of the characteristics of the electro-optical filter 5A, it is possible to emit illumination light with an appropriate light amount and color balance in a short time after the completion of the switching of the observation mode.

[0095] Fig. 17 is a table for explaining the light quantity correction values ​​stored in the memory 6 in the third embodiment. In the figure, P1 indicates the light quantity value obtained from the measurement result of each optical sensor 2SE in the case of the characteristic for white light observation in which the electro-optical filter 5A outputs the incident light as it is, and P2 indicates the light quantity value obtained from the measurement result of each optical sensor 2SE at each timing until the electro-optical filter 5A changes to the characteristic required for special light observation in the same control state as the control state of each LED 2L at the time of P1 measurement. The example of Fig. 16 shows P2 when P1 is set to 1 for each elapsed time from the start of the change.

[0096] The elapsed time (seconds) in Fig. 17 indicates the time it takes for the electro-optical filter 5A to change from the characteristics for white light observation to the characteristics for special light observation. T1 is the elapsed time of 0 seconds, and T5 is the time it takes to completely transition to the characteristics for special light observation. At the elapsed time T1, P1 = P2 = 1, and the light intensity correction value γ is 1. As the elapsed time increases, the light reflected by the filter increases, and P2 becomes larger. The light intensity correction value γ becomes smaller as the elapsed time increases.

[0097] The light intensity correction value γ is calculated as the ratio of the light intensity value P1 when the electro-optic filter 5A has the characteristics for white light observation to the light intensity value P2 when the electro-optic filter 5A changes to the characteristics for special light observation, and is expressed as γ=P1 / P2. The control circuit 1A calculates the light intensity value P1 obtained from the measurement results of each optical sensor 2SE with the electro-optic filter 5A set to the characteristics for white light observation. The control circuit 1A changes the applied voltage to the electro-optic filter 5A without changing the control of each optical sensor 2SE, and calculates the light intensity value P2 obtained from the measurement results of each optical sensor 2SE for each elapsed time from the start of the change in the applied voltage. The control circuit 1A calculates the light intensity correction value γ by calculating P1 / P2.

[0098] It is also conceivable that the light quantity correction value γ changes depending on the range of the voltage applied to the electro-optical filter 5A. Taking this case into consideration, the light quantity correction value γ is calculated for each range of the applied voltage. As shown in FIG. 17, the control circuit 1A associates the elapsed time with the light quantity correction value γ for each range of the applied voltage, and stores them in the memory 6.

[0099] When switching the observation mode, the control circuit 1A obtains the elapsed time from the start of changing the applied voltage to the electro-optical filter 5A. The control circuit 1A reads out the light intensity correction value from the memory 6 using the obtained elapsed time. The control circuit 1A obtains the light intensity detection value based on the detection output of each optical sensor 2SE, and obtains the light source light intensity value according to the current characteristics of the electro-optical filter 5A for each LED 2L by multiplying the light intensity detection value by the light intensity correction value. The control circuit 1A may also estimate the light source light intensity value after the characteristic change of the electro-optical filter 5A is completed from the current light source light intensity value. The control circuit 1A may also obtain the light source light intensity value after the characteristic change of the electro-optical filter 5A is completed by the above-mentioned statistical method.

[0100] The control circuit 1A controls the light intensity of each LED 2L based on the light source intensity value thus determined, thereby enabling imaging with accurate color balance immediately after the characteristic change of the electro-optical filter 5A is completed.

[0101] The other configurations and operations are similar to those of the first and second embodiments.

[0102] The present invention is not limited to the above-described embodiments, and can be embodied by modifying the components without departing from the spirit of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiments. For example, some of the components shown in the embodiments may be deleted. Furthermore, components from different embodiments may be appropriately combined.

Claims

1. A first light source; An optical sensor; a light amount information acquiring unit that acquires first information regarding an amount of light received by the light sensor; An optical member; an optical member moving unit that moves the optical member from a first position to a second position to insert or remove the optical member into or from an optical path of light emitted from the first light source; a position information acquisition unit that acquires second information regarding a position of the optical member moving from the first position to the second position; a control unit that outputs control information for controlling the first light source based on the first information and the second information; A light source device comprising:

2. the control unit determines a first amount of light emitted by the first light source based on third information obtained by correcting a correction value for removing an influence of reflected light from the optical member from the amount of light received by the optical sensor based on the second information and the first information, and outputs control information for controlling the first light source based on the determined first amount of light.

2. The light source device according to claim 1.

3. The second information indicates a degree of insertion of the optical member into the optical path.

2. The light source device according to claim 1.

4. A memory for storing information indicating a correspondence relationship between the second information and the third information.

3. The light source device according to claim 2.

5. The memory stores the third information obtained based on a comparison between the first information when the optical member is located at the first position and the first information when the optical member is located at the second position from the first position in a state where power to the first light source is constant.

5. The light source device according to claim 4.

6. Further comprising a second light source.

2. The light source device according to claim 1.

7. a memory for storing information indicating a correspondence relationship between the second information and third information obtained by correcting a correction value for removing an influence of reflected light from the optical member from the amount of light received by the optical sensor based on the second information, for the first light source and the second light source, separately for the first light source and the second light source; 7. The light source device according to claim 6.

8. The optical member is supported by a rotating frame member.

2. The light source device according to claim 1.

9. The position information acquisition unit acquires the second information based on a rotation angle of the rotating frame member.

9. The light source device according to claim 8.

10. The optical member is an optical filter.

2. The light source device according to claim 1.

11. The control unit is provided with the second information acquired by the position information acquisition unit, and controls the first light source and the second light source independently by referring to the memory.

8. The light source device according to claim 7.

12. The control unit completes control of the first light source and the second light source by the time the optical member reaches the second position.

12. The light source device according to claim 11.

13. The control unit controls the first and second light sources based on a result obtained by statistically processing the third information acquired while the optical member is moving from the first position to the second position.

12. The light source device according to claim 11.

14. The control unit adopts an arithmetic mean, a geometric mean, a mode, or a median as the statistical processing.

14. The light source device according to claim 13.

15. The control unit, during control of the first and second light sources based on the third information acquired while the optical member is moving from the first position to the second position, newly acquires the third information in a state where the optical member is located at the second position, and thereafter controls the first and second light sources based on the reacquired third information.

14. The light source device according to claim 13.

16. A light source; An optical sensor; a light amount information acquiring unit that acquires first information regarding an amount of light received by the light sensor; An optical member; an optical element driving circuit that changes the optical element from a first characteristic to a second characteristic to limit light emitted from the light source; a time information acquiring unit that acquires second information regarding a time from a start of a characteristic change during a characteristic change of the optical member from the first characteristic to the second characteristic; a control unit that outputs control information for controlling the light source based on the first information and the second information; A light source device comprising:

17. An endoscope, A first light source; An optical sensor; a light amount information acquiring unit that acquires first information regarding an amount of light received by the light sensor; An optical member; an optical member moving unit that moves the optical member from a first position to a second position to insert or remove the optical member into or from an optical path of light emitted from the first light source; a position information acquisition unit that acquires second information regarding a position of the optical member moving from the first position to the second position; a control unit that outputs control information for controlling the first light source based on the first information and the second information; An endoscope system comprising:

18. A light amount control method for controlling a light amount of a light source by a processor, comprising: The light source emits light, The optical sensor receives light, The processor, Obtaining first information regarding an amount of light received by the optical sensor; acquiring second information on a position of an optical member that is inserted or removed from an optical path of light emitted from the light source, the optical member being moved from a first position to a second position; outputting control information for controlling the light source based on the first information and the second information; A light quantity control method comprising:

Images