JP2018038637A - Endoscope apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire a narrow band light image and a white light image which have excellent image quality.SOLUTION: An endoscope apparatus 1 is provided, comprising a light source device 13 and an imaging device 10, the light source device 13 comprises first, second and third solid-state lighting elements 15V, 15B, 15G for emitting purple, blue and green lights, respectively and a control part 17 for controlling the first, second and third solid-state lighting elements 15V, 15B, 15G, a color filter array of the imaging device 10 includes a cyan color filter and a blue color filter transmitting green, blue and purple lights, and the control part 17 turns on the first and third solid-state lighting elements 15V, 15G simultaneously when turning on the first and third solid-state lighting elements 15v, 15G and turning off the second solid-state lighting element 15B, and turns on the second and third solid-state lighting elements 15B, 15G in turn when turning on the second and third solid-state lighting elements 15B, 15G.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an endoscope apparatus.

  Conventionally, special light observation, such as NBI (Narrow Band Imaging) or BLI (Blue Laser Imaging), is used to irradiate a site to be observed and image the reflected light (for example, patent literature). 1 and 2)), it is easy to find the lesion. On the other hand, an image sensor provided with a color filter of RGB Bayer arrangement is used so that simultaneous observation can be performed while obtaining good color reproduction in white light observation.

  In special light observation, B information is important because the information of reflected light from purple to blue (B information) greatly contributes to the images of capillaries and the like on the mucous membrane surface layer. However, in the RGB Bayer array, the B pixels for detecting reflected light from purple to blue are only one-fourth of all pixels, so that the resolution of capillaries and the like is insufficient. Patent Documents 1 and 2 attempt to solve such problems.

  In Patent Document 1, B information is acquired even in the G pixel by the G pixel having the sub-sensitivity region in the purple wavelength region, and the B pixel is obtained from the G pixel signal by performing a correlation operation between the G pixel signal and the R pixel signal. Information is extracted. In Patent Document 2, when narrowband light observation is performed with an endoscope using a complementary color imaging device, blue narrowband light and green narrowband light are surfaced in order to improve the separation between B information and G information. Light is emitted sequentially.

JP 2012-170639 A Japanese Patent Laying-Open No. 2015-66062

  However, in the case of Patent Document 1, there is a problem that, when acquiring a white light image, in a region where the correlation between the G pixel signal and the R pixel signal is low, the B information extraction accuracy is low. Further, when B information is extracted from the G pixel signal by image processing, a gain is applied to the image signal. There is a problem that image noise increases due to this gain. When the frame sequential method of Patent Document 2 is used, there is a problem that color shift occurs in a narrowband light image.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an endoscope apparatus that can acquire a narrow-band light image and a white light image with good image quality.

In order to achieve the above object, the present invention provides the following means.
One embodiment of the present invention includes a light source device that outputs illumination light that illuminates a subject, and a color filter array that includes two-dimensionally arranged color filters, and photographs the subject illuminated by the illumination light. A first solid-state illumination element that emits light having a peak intensity in a violet wavelength region, and a second solid-state illumination element that emits light having a peak intensity in a blue wavelength region A third solid state lighting element that emits light having a peak intensity in the green wavelength region, and turning on and off the first solid state lighting element, the second solid state lighting element, and the third solid state lighting element The color filter array includes a cyan color filter and a blue color filter, and the cyan color filter is green, blue And when the control unit turns on the first solid state lighting element and the third solid state lighting element and turns off the second solid state lighting element. When the first solid-state lighting element and the third solid-state lighting element are turned on at the same time, and the second solid-state lighting element and the third solid-state lighting element are turned on, the second solid-state lighting element is used. And an endoscope apparatus that sequentially turns on the third solid-state lighting elements.

  According to one embodiment of the present invention, when illumination light including purple, blue, and green light is irradiated on a subject, the reflected purple, blue, and green light incident on the image sensor from the subject is transmitted through the color filter array. Then, it is detected by the pixel of the image sensor.

  When acquiring a narrow-band light image, the subject is irradiated only with purple light and green light whose wavelengths are separated from each other. At this time, the control unit controls the first and third solid state lighting elements so that purple light and green light are simultaneously irradiated. Purple reflected light including capillary information is detected not only by the B pixel corresponding to the blue color filter (B filter) but also by the Cy pixel corresponding to the cyan color filter (Cy filter). As a result, the amount of information of purple reflected light containing a large amount of information on capillaries increases, so that a high-quality narrow-band light image with high resolution can be acquired.

  Since the Cy pixel also detects green reflected light in addition to purple reflected light, it is necessary to extract information of the green reflected light from the Cy pixel with high accuracy in order to improve color separation. Since the information contained in the B pixel signal is dominated by the purple reflected light information, the B information predicted from the Cy pixel and the B pixel signal located in the vicinity thereof is subtracted from the Cy pixel signal. Thus, the information of the green reflected light can be extracted with high accuracy.

  On the other hand, when acquiring a white light image, the subject is irradiated with purple, blue, and green light. At this time, the control unit controls the first, second, and third solid state lighting elements so that the blue light and the green light whose wavelengths are close to each other are sequentially irradiated. Thereby, since the blue reflected light and the green reflected light are detected by the Cy pixel in a time division manner, the information of the blue reflected light and the information of the green reflected light are acquired separately without being mixed. Therefore, it is not necessary to separate the information of the blue and green reflected light by applying gain to the signal by image processing. Thereby, it is possible to obtain a white light image with good color reproduction while suppressing an increase in noise.

In the above aspect, the light source device may include a fourth solid state lighting element that emits light having a peak intensity in a wavelength region of 580 nm to 700 nm.
By doing in this way, the information of red reflected light is acquired by appropriate intensity | strength with the orange to red light which a 4th solid-state lighting element emits. As a result, it is possible to obtain a white light image with reduced noise by suppressing the gain applied to the red reflected light signal in order to adjust the white balance of the white light image.

In the above aspect, the color filter array may include a red color filter.
In this way, the color reproducibility of the white light image can be improved by detecting the red reflected light from the subject by the pixel corresponding to the red color filter.

In the above aspect, the color filter array may include a magenta color filter.
By doing so, in addition to red reflected light, purple to blue reflected light is detected by the pixels corresponding to the magenta color filter. Thereby, while improving the color reproducibility of the white light image, the information amount of reflected light from purple to blue can be increased, and the resolution of the narrow-band light image can be further improved.

In the above aspect, the ratio of the number of the cyan color filters in the color filter array may be a quarter or more.
By doing in this way, the number of Cy pixels becomes 1/4 or more of all the pixels of an image sensor. Thereby, it is possible to improve the resolution of the surface capillary in the narrow-band light image while maintaining the image quality of the white light image.

  According to the present invention, it is possible to acquire a narrow band light image and a white light image with good image quality.

1 is an overall configuration diagram of an endoscope apparatus according to an embodiment of the present invention. It is a figure which shows the color filter array which the image pick-up element of the endoscope apparatus of FIG. 1 has. It is a figure which shows the spectral sensitivity characteristic of the image pick-up element which has the color filter array of FIG. In the white light observation mode of the endoscope apparatus of FIG. 1, (a) the spectral characteristics of light output from the light source device in the first period and (c) the second period, and (b) the first period and (D) It is a figure which shows the spectral characteristics contained in the signal output from the image sensor in a 2nd period. FIG. 2 is a diagram illustrating (a) spectral characteristics of light output from a light source device and (b) spectral characteristics included in a signal output from an image sensor in the narrowband light observation mode of the endoscope apparatus of FIG. 1. . It is a whole block diagram of the 1st modification of the endoscope apparatus of FIG. In the white light observation mode of the endoscope apparatus of FIG. 6, (a) the spectral characteristics of light output from the light source device in the first period and (c) the second period, and (b) the first period and (D) It is a figure which shows the spectral characteristics contained in the signal output from the image sensor in a 2nd period. It is a figure which shows the color filter array in the 2nd modification of the endoscope apparatus of FIG. It is a figure which shows the spectral sensitivity characteristic of an image pick-up element provided with the color filter array of FIG. In the white light observation mode of the endoscope apparatus including the color filter array of FIG. 8, (b) spectral characteristics of light output from the light source device during the first period and (c) the second period; It is a figure which shows the spectral characteristic contained in the signal output from the image pick-up element in the 1st period and (d) 2nd period. In the narrow-band light observation mode of the endoscope apparatus including the color filter array of FIG. 8, (a) spectral characteristics of light output from the light source apparatus, and (b) spectral characteristics included in the signal output from the image sensor. FIG.

Hereinafter, an endoscope apparatus 1 according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, an endoscope apparatus 1 according to the present embodiment is inserted into a body to illuminate a subject with illumination light and acquire an image signal, and at the proximal end of the scope 2. A drive control device 3 is connected to supply illumination light to the scope 2 and generate an image, and a monitor 4 is connected to the drive control device 3.

The scope 2 includes an illumination optical system 5 that irradiates a subject with illumination light, and an imaging optical system 6 that receives reflected light of the illumination light from the subject and obtains an image signal of the subject.
The illumination optical system 5 is disposed in the scope 2 along the longitudinal direction and guides the illumination light from the proximal end to the distal end. The illumination optical system 5 is provided at the distal end of the scope 2 and emitted from the distal end of the light guide member 7. And an illumination lens 8 for emitting the illumination light toward the front of the distal end of the scope 2.

  An imaging optical system 6 is provided at the distal end of the scope 2 and collects an objective lens 9 that collects reflected light from the subject, and an imaging element 10 that captures an image of the subject connected by the objective lens 9 and acquires an image signal. And an analog / digital (AD) converter 11 for converting the image signal output from the image sensor 10 into a digital signal.

  FIG. 2 shows a part of the color filter array 12 provided on the imaging surface of the imaging device 10 and made up of a number of two-dimensionally arranged color filters. As shown in FIG. 2, the color filter array 12 is obtained by replacing the G filter with a Cy filter in a so-called Bayer array. Specifically, the color filter array 12 includes a red color filter (R filter), a cyan color filter (Cy filter), and a blue color filter (B filter). One unit array is composed of one R filter, one B filter, and two Cy filters arranged in a square, and the unit arrays are arranged in the row direction and the column direction.

  Each color filter corresponds to one pixel of the image sensor 10. Hereinafter, pixels corresponding to the R filter, the Cy filter, and the B filter are referred to as an R pixel, a Cy pixel, and a B pixel, respectively. Therefore, the ratio of the number of Cy pixels to the total number of pixels of the image sensor 10 is ½. The R pixel, the Cy pixel, and the B pixel respectively detect the light transmitted through the R filter, the Cy filter, and the B filter, and acquire the R signal, the Cy signal, and the B signal, respectively. The R signal, the Cy signal, and the B signal are transmitted to the image processing device 14 in the drive control device 3 via the AD converter 11.

  FIG. 3 shows the spectral sensitivity characteristics of the R pixel, Cy pixel, and B pixel of the image sensor 10. The spectral sensitivity characteristics of the R pixel, the Cy pixel, and the B pixel are obtained by multiplying the transmittance characteristics of the R filter, the Cy filter, and the B filter and the spectral sensitivity characteristics of the semiconductor that is the light receiving unit, respectively. As shown in FIG. 3, since the R filter selectively transmits red light, the R pixel has high sensitivity in the red wavelength region (R region). Since the Cy filter selectively transmits green, blue, and violet light, the Cy pixel has high sensitivity in the green, blue, and violet wavelength regions (G region, B region, and V region). Since the B filter selectively transmits blue and violet light, the B pixel has high sensitivity in the B region and the V region.

The drive control device 3 includes a light source device 13 that generates illumination light and an image processing device 14 that processes an image signal received from the imaging optical system 6 to generate an image.
The light source device 13 includes three colors of LEDs 15V, 15B, and 15G, a movable narrow band filter 16, a light source control unit (control unit) 17 that controls turning on and off of the LEDs 15V, 15B, and 15G, and a narrow band filter 16. And a filter control unit 18 for controlling the movement of.

  The V-LED (first solid state lighting element) 15V emits violet narrow band light (V light) having a peak intensity in a V region (for example, 380 nm to 430 nm). The B-LED (second solid state lighting element) 15B emits blue narrow band light (B light) having a peak intensity in the B region (for example, 430 nm to 480 nm). The G-LED (third solid state lighting element) 15G uses a phosphor and emits green broadband light (G light) having a peak intensity in a G region (for example, 480 nm to 580 nm). G light has a wider spectral width than V light and B light, and has an intensity in the R region.

  The V light, B light, and G light emitted from the LEDs 15V, 15B, and 15G are combined with each other by the combining optical system 19 and incident on the condensing lens 20 along a single optical axis. Thus, the light is condensed on the base end surface of the light guide member 7. The multiplexing optical system 19 includes, for example, a combination of a plurality of dichroic mirrors.

  The narrowband filter 16 includes a first position on the optical path of G light (see the solid line in FIG. 1) between the G-LED 15G and the multiplexing optical system 19, and a second position off the optical path of G light. (Refer to the two-dot chain line in FIG. 1). The narrow band filter 16 transmits only light in a narrow wavelength region of green.

  The light source control unit 17, the filter control unit 18, and the image processing device 14 are operated for each of a white light observation mode for acquiring a white light image and an NBI observation mode (narrowband light observation mode) for acquiring an NBI image. It has become.

  In the white light observation mode, the light source control unit 17 turns on the V-LED 15V, the B-LED 15B, and the G-LED 15G, and the filter control unit 18 arranges the narrowband filter 16 at the second position. At this time, the light source control unit 17 performs the first period in which only the V-LED 15V and the B-LED 15B are turned on as shown in FIG. 4A, and the G-LED 15G as shown in FIG. 4C. The second period in which only the light is turned on is alternately repeated.

  Therefore, in the first period, as shown in FIG. 4A, only the V light Lv and the B light Lb are irradiated to the subject. Then, as shown in FIG. 4B, the reflected light of the V light Lv and the B light Lb is detected by the Cy pixel and the B pixel. In the second period, as shown in FIG. 4C, only the G light Lg is irradiated to the subject. Then, as shown in FIG. 4D, among the reflected light of the G light Lg, the G region component is detected by the Cy pixel, and the R region component is detected by the R pixel.

  In the white light observation mode, the image processing device 14 assigns the Cy signal and B signal acquired in the first period to the B channel, assigns the Cy signal acquired in the second period to the G channel, and outputs the second signal. The white light image is generated by assigning the R signal acquired in the period to the R channel and further performing other processing. Note that the Cy signal acquired in the first period may not be assigned to the B channel, and only the B signal may be assigned to the B channel.

  In the NBI observation mode, the light source control unit 17 turns on the V-LED 15V and the G-LED 15G and turns off the B-LED 15B, and the filter control unit 18 arranges the narrowband filter 16 at the first position. At this time, as shown in FIG. 5A, the light source control unit 17 turns on the V-LED 15V and the G-LED 15G simultaneously.

  Accordingly, as shown in FIG. 5A, only the V light Lv and the green narrow band light (G ′ light) Lg ′ that has passed through the narrow band filter 16 are irradiated to the subject. Then, as shown in FIG. 5B, the reflected light of the V light Lv is detected by the B pixel and the Cy pixel, and the reflected light of the G ′ light Lg ′ is detected by the Cy pixel. That is, the Cy pixel simultaneously detects the reflected light of both the V light Lv and the G ′ light Lg ′, and acquires a Cy signal including information on the reflected light of both the V light Lv and the G ′ light Lg ′.

  In the NBI observation mode, the image processing apparatus 14 assigns the B information predicted from the B signal and the Cy signal to the B channel and the G channel, assigns the difference obtained by subtracting the B information from the Cy signal to the R channel, and the other By adding processing, an NBI image is generated.

  As described above, the Cy signal includes the reflected light information of both the V light Lv and the G ′ light Lg ′. Further, the B signal includes information on both the V light Lv and G ′ light Lg ′, but the sensitivity of the B pixel in the G region is sufficiently lower than the sensitivity in the V region, and thus information on the reflected light of the V light Lv. Can be obtained with high purity. Therefore, by predicting the B information from the Cy signal and the B signal and subtracting the B information from the Cy signal, it is possible to accurately extract the reflected light information of the G ′ light Lg ′.

The image processing device 14 transmits the generated white light image or NBI image to the monitor 4.
The monitor 4 displays the received white light image or NBI image.

  Whether to perform white light observation or NBI observation is determined by the user operating the observation mode changeover switch 21 provided in the scope 2. The observation mode changeover switch 21 allows the user to select one of the white light observation mode and the NBI observation mode. Information on the selected mode is transmitted from the observation mode changeover switch 21 to the light source control unit 17, the filter control unit 18, and the image processing device 14. The light source control unit 17 and the filter control unit 18 execute the above-described control according to the received mode information, and the image processing device 14 generates a white light image or an NBI image according to the received mode information.

Next, the operation of the endoscope apparatus 1 configured as described above will be described.
When the user selects the white light observation mode with the observation mode changeover switch 21, the light source control unit 17 and the filter control unit 18 control the LEDs 15V, 15B, 15G and the narrowband filter 16 in the white light observation mode, thereby The subject is irradiated with B light and G light alternately. Then, the reflected light of the V light and the B light and the reflected light of the G light are alternately detected by the imaging device 10, and the B signal and the Cy signal including information on the reflected light of the V light and the B light and the reflection of the G light are reflected. Cy signals and R signals including light information are alternately transmitted to the image processing device 14. In the image processing apparatus 14, the B signal and the Cy signal in the first period are assigned to the B channel, the Cy signal and the R signal in the second period are assigned to the G channel and the R channel, respectively, and other image processing is applied. As a result, a white light image is generated and displayed on the monitor 4.

  On the other hand, when the user selects the NBI observation mode by the observation mode changeover switch 21, the light source control unit 17 and the filter control unit 18 control the LEDs 15V, 15B, 15G and the narrowband filter 16 in the NBI observation mode, thereby allowing the V light and The subject is simultaneously irradiated with G ′ light. Then, reflected light of V light and G ′ light is detected by the image sensor 10, and a Cy signal including information on the reflected light of V light and G ′ light and a B signal including information on the reflected light of V light Lv are included. It is transmitted to the image processing device 14. In the image processing apparatus 14, B information predicted from the B signal and the Cy signal is assigned to the B channel and the G channel, G information obtained by subtracting the B information from the Cy signal is assigned to the R channel, and other images By applying the processing, an NBI image is generated and displayed on the monitor 4.

  As described above, according to the present embodiment, by providing the imaging element 10 with the Cy filter that transmits the light in the G, B, and V regions, the reflected light of the V light including the information on the capillaries on the surface layer of the living tissue can be obtained. , It is also detected by the Cy pixel in addition to the B pixel. Therefore, the information on the reflected light of the V light Lv used for generating the NBI image increases. This has an advantage that a high-resolution NBI image can be acquired.

  Further, when observing white light, it is possible to obtain a white light image with high color reproducibility by using the broadband G light Lg having intensity also in the R region and detecting the reflected light of the R region by the R pixel. There is an advantage. Further, the first period in which only the V-LED 15V and the B-LED 15B are lit and the second period in which only the G-LED 15G is lit are alternately repeated, so that the V light, the B light, and the G light are displayed in a frame sequential manner. By irradiating the subject, the Cy pixel detects the reflected light of the V region, the reflected light of the B region, and the reflected light of the G region in a time division manner. Thereby, the information of the B and V regions and the information of the G region can be separated without applying gain to the image signal, and there is an advantage that a white light image with reduced noise can be acquired.

  If the V-LED 15V and the B-LED 15B and the G-LED 15G are turned on at the same time, since the B pixel has sensitivity in the G region, the B signal includes a lot of information on the reflected light of the G light Lg. Therefore, the accuracy of separating the V and B area information and the G area information from the Cy pixel signal is lowered, and the color reproducibility is lowered. In addition, it is necessary to apply a high gain to the image signal when separating the information in the V and B regions and the information in the G region, resulting in a noisy white light image.

In the present embodiment, the color filter array 12 has a unit array composed of four color filters arranged in a square, but the color filter array pattern of the color filter array 12 is not limited to this. .
For example, in a 2 × 2 unit array, the number of Cy filters may be one and the number of R filters or B filters may be two. Alternatively, the unit array may be configured by 9 × 3 × 3 color filters or 16 × 4 × 4 color filters. In any arrangement pattern, the ratio of the number of Cy filters to the total number of color filters in the color filter array is preferably ¼ or more.

  In the present embodiment, the case where an NBI image is acquired as a narrowband light image has been described. However, a narrowband light image other than the NBI image, for example, a BLI image may be acquired.

Next, a modification of this embodiment will be described.
In the endoscope apparatus 100 according to the first modification of the present embodiment, the light source device 131 further includes an R-LED (fourth solid state lighting element) 15R as shown in FIG. The R-LED 15R emits red narrowband light (R light) having a peak intensity in an orange to red wavelength region (for example, 580 nm to 700 nm).
In this modification, the control by the light source control unit 17 in the NBI observation mode is the same as that in the above-described embodiment, but the control by the light source control unit 17 in the white light observation mode is different from the above-described embodiment.

In the white light observation mode, the light source control unit 17 turns on only the V-LED 15V and the B-LED 15B in the first period as shown in FIG. 7A, and the first light source control unit 17 as shown in FIG. 7C. Only the G-LED 15G and the R-LED 15R are turned on in the period 2. In the first period, as shown in FIG. 7B, the B signal and the Cy signal assigned to the B channel are acquired. Note that the Cy signal acquired in the first period may not be assigned to the B channel, and only the B signal may be assigned to the B channel. In the second period, as shown in FIG. 7D, a Cy signal assigned to the G channel and a larger R signal assigned to the R channel are acquired.
In this way, the R signal has an appropriate magnitude with respect to the signals assigned to the B channel and the G channel, so that the gain applied to the R signal for white balance adjustment can be suppressed, and the white light image can be reduced. Noise can be further reduced.

  In the endoscope apparatus according to the second modification of the present embodiment, the color filter array 121 includes a magenta color filter (Mg filter) instead of the R filter, as shown in FIG. FIG. 9 shows spectral sensitivity characteristics of the Mg pixel, Cy pixel, and B pixel of the image sensor 10. The Mg pixel is a pixel corresponding to the Mg filter. The Mg filter has two transmission bands in the B and V regions and the R region, and selectively transmits blue and violet light and red light.

  In this modification, the light source device 131 includes the four LEDs 15V, 15B, 15G, and 15R described above. The control of the LEDs 15V, 15B, 15G, and 15R by the light source controller 17 is the same as that in the first modification as shown in FIGS. 10 (a), 10 (c), and 11 (a).

In the generation of the white light image, the B signal, the Cy signal, and the Mg signal acquired in the first period are assigned to the B channel. Note that the Cy signal and the Mg signal acquired in the first period may not be assigned to the B channel, and only the B signal may be assigned to the B channel. In addition, the Cy signal acquired in the second period is assigned to the G channel, and the Mg signal acquired in the second period is assigned to the R channel.
On the other hand, in the generation of the NBI image, the Mg signal is assigned to the B channel and the G channel in addition to the B signal and the Cy signal. As described above, the reflected light of the V light Lv is also detected by the Mg pixel, and the information amount of the reflected light of the V light Lv in the NBI image is further increased, so that a higher resolution NBI image of the capillary is acquired. be able to.

  In this modification, instead of the light source device 131, the light source device 13 that does not include the R-LED 15R may be used. Also in this case, the resolution of the NBI image can be improved.

DESCRIPTION OF SYMBOLS 1,100 Endoscope apparatus 10 Image pick-up element 12,121 Color filter array 13,131 Light source device 15V V-LED (1st solid-state lighting element)
15B B-LED (second solid state lighting element)
15G G-LED (third solid state lighting element)
15R R-LED (fourth solid state lighting element)
17 Light source control unit (control unit)

Claims (5)

A light source device that outputs illumination light for illuminating a subject;
A color filter array including a plurality of color filters arranged in a two-dimensional array, and an image sensor that photographs the subject illuminated by the illumination light,
The light source device is
A first solid state lighting element that emits light having a peak intensity in a purple wavelength region;
A second solid state lighting element that emits light having a peak intensity in a blue wavelength region;
A third solid state lighting element that emits light having a peak intensity in the green wavelength region;
A control unit that controls turning on and off of the first solid-state lighting element, the second solid-state lighting element, and the third solid-state lighting element;
The color filter array includes a cyan color filter and a blue color filter, and the cyan color filter has optical characteristics of transmitting green, blue, and violet light;
The control unit is
When turning on the first solid state lighting element and the third solid state lighting element and turning off the second solid state lighting element, the first solid state lighting element and the third solid state lighting element are simultaneously turned on. Turn on
An endoscope apparatus that turns on the second solid-state lighting element and the third solid-state lighting element in order when the second solid-state lighting element and the third solid-state lighting element are turned on.   The endoscope apparatus according to claim 1, wherein the light source device includes a fourth solid-state illumination element that emits light having a peak intensity in a wavelength region of 580 nm to 700 nm.   The endoscope apparatus according to claim 1, wherein the color filter array includes a red color filter.   The endoscope apparatus according to claim 1, wherein the color filter array includes a magenta color filter.   The endoscope apparatus according to any one of claims 1 to 4, wherein a ratio of the number of the cyan color filters in the color filter array is ¼ or more.

Images