JP6508640B2 - Endoscope device - Google Patents

Description

  The present invention relates to an endoscope apparatus that measures a subject while acquiring a two-dimensional image of the subject.

  An imaging apparatus using an imaging element such as a CCD or a CMOS image sensor simultaneously receives reflected light from an object by a large number of light receiving elements arranged in a matrix, and acquires an object image. In the case of an endoscope for imaging a dark body, an image of an area illuminated by light from a light source is acquired.

  On the other hand, in the light scanning type imaging apparatus, while scanning and irradiating a subject with a light spot, the reflected light is sequentially received, and a subject image is created based on the received light data.

  For example, in the light scanning endoscope, the scanning irradiation of the light spot is performed by two-dimensionally scanning the tip of the optical fiber which guides the light from the light source by the optical fiber scanning unit.

  U.S. Pat. No. 6,563,105 discloses a system for acquiring a three-dimensional image of a scan-irradiated object using a photometric stereo method.

  In the photometric stereo method, a three-dimensional image is created on the basis of reflected light incident on a plurality of discrete light receiving windows.

  For this reason, it is not easy to reduce the outer diameter of the distal end of the endoscope.

  In addition to the RGB light for acquiring a color image, the illumination light includes infrared light for performing distance measurement. In addition to the red light receiving element, the green light receiving element, and the blue light receiving element, the light receiving unit has a complex configuration including an infrared light receiving element to perform distance measurement. In addition, since white light on which RGB light is superimposed is used as illumination light, a spectroscope such as a dichroic mirror that separates red light, green light, and blue light is required in front of the light receiving unit.

U.S. Pat. No. 6,563,105

  An embodiment of the present invention aims to provide an endoscope apparatus that is high-performance and has a simple configuration that measures a subject while acquiring a two-dimensional image of the subject.

An endoscope apparatus according to an embodiment includes a light source for generating irradiation light, a first optical fiber for spot irradiation of the guided irradiation light from a tip toward a subject, and the tip of the first optical fiber By changing the direction of the light source, a scanning unit that scans the irradiation light, a light receiving unit that outputs an electric signal based on the reflected light from the object irradiated with the irradiation light, and a signal that processes the electric signal a processing unit, and wherein the illumination light, wherein the observation component for obtaining a two-dimensional image of the object, which is superimposed on the observation component, and the subject using the time-of-flight method And the measurement component including the measurement component based on the observation component of the reflected light and the measurement signal based on the measurement component of the reflected light. and it outputs a signal, before Signal processing section outputs the two-dimensional image data by processing the observation signal, and outputs the measurement data to process the measurement signal.

  According to the embodiment of the present invention, it is possible to provide an endoscope apparatus which is high-performance and has a simple configuration, which measures a subject while acquiring a two-dimensional image of the subject.

It is a perspective view of an endoscope apparatus of a 1st embodiment. It is a block diagram of the endoscope apparatus of 1st Embodiment. It is explanatory drawing of the illumination light of the endoscope apparatus of 1st Embodiment. It is explanatory drawing of the scanning method of the illumination light of the endoscope apparatus of 1st Embodiment. It is explanatory drawing of the scanning method of the illumination light of the endoscope apparatus of 1st Embodiment. It is explanatory drawing of the reflected light of the endoscope apparatus of 1st Embodiment. It is sectional drawing of the light receiving element of the endoscope apparatus of 1st Embodiment. It is an example of the two-dimensional color image of the endoscope apparatus of 1st Embodiment. It is explanatory drawing of the distance measurement method of the endoscope apparatus of 1st Embodiment. It is an example of the distance image of the endoscope apparatus of 1st Embodiment. It is an example of the three-dimensional color image of the endoscope apparatus of 1st Embodiment. It is a cross-sectional view of the light receiving element of an endoscope apparatus according to a modification of the first embodiment. It is an illustration of reflected light of an endoscope apparatus according to a modification of the first embodiment. It is a block diagram of the endoscope apparatus of 2nd Embodiment. It is explanatory drawing of the illumination light of the endoscope apparatus of 2nd Embodiment. It is explanatory drawing of the reflected light of the endoscope apparatus of 2nd Embodiment. It is sectional drawing of the light receiving element of the endoscope apparatus of the modification of 2nd Embodiment. It is explanatory drawing of the reflected light of the endoscope apparatus of the modification of 2nd Embodiment. It is explanatory drawing of the illumination light of the endoscope apparatus of 3rd Embodiment. It is explanatory drawing of the reflected light of the endoscope apparatus of 3rd Embodiment. It is explanatory drawing of the reflected light of the endoscope apparatus of the modification of 3rd Embodiment. It is explanatory drawing of the illumination light of the endoscope apparatus of 4th Embodiment. It is explanatory drawing of the reflected light of the endoscope apparatus of 4th Embodiment. It is sectional drawing of the light receiving element of the endoscope apparatus of the modification of 4th Embodiment. It is explanatory drawing of the reflected light of the endoscope apparatus of the modification of 4th Embodiment. It is a block diagram of the endoscope apparatus of 5th Embodiment.

First Embodiment
An endoscope apparatus 1 of the present embodiment shown in FIG. 1 includes an optical scanning endoscope 10, a main body 20, and a monitor 30.

  The endoscope 10 has an elongated insertion portion 11 which is inserted into a living body, an operation portion 12 and a universal cable 13. The insertion portion 11 includes a distal end portion 11A, a bending portion 11B, and a flexible tube portion 11C. The endoscope 10 is a so-called flexible endoscope, but may be a so-called rigid endoscope in which the insertion portion 11 is rigid.

  The operation portion 12 is provided with a bending operation knob 12A and the like for bending the bending portion 11B. The connecting portion between the insertion portion 11 and the operation portion 12 is a gripping portion 12B which is gripped by the user.

  A universal cable 13 extended from the operation unit 12 is connected to the main unit 20 via the connector 14. The main body unit 20 is connected to a monitor 30 for displaying an image.

  Next, FIG. 2 shows the configuration of the endoscope apparatus 1.

  The main body unit 20 of the endoscope apparatus 1 includes a light source 40, a scan control unit 25, a light receiving element 21 as a light receiving unit, a signal processing unit 22, an image generation unit 23, and a control unit 24.

  The light source 40 generates illumination light. The scan control unit 25 controls the scanning unit 15 to scan the irradiation light. The light receiving element 21 receives the reflected light from the object irradiated with the irradiation light, and outputs an electrical signal based on the reflected light. The signal processing unit 22 processes the electrical signal output from the light receiving element 21. The image generation unit 23 processes the electrical signal output from the signal processing unit 22 to generate an endoscopic image. The control unit 24 controls the entire endoscope apparatus 1.

  The signal processing unit 22, the image generation unit 23, and the control unit 24 are formed of semiconductor elements such as a CPU operating according to a predetermined program. The signal processing unit 22, the image generation unit 23, and the control unit 24 may be physically independent semiconductor elements, or one semiconductor element may have a plurality of functions.

  The light source 40 generates an R light source 41 that generates red wavelength light (for example, 620 nm to 750 nm), a G light source 42 that generates green wavelength light (for example, 495 nm to 570 nm), and blue wavelength light (for example, 450 nm to 495 nm) And B light source 43. The R light source 41, the G light source 42, and the B light source 43 are, for example, laser light sources. As described later, the red wavelength light generated by the R light source 41 is high-frequency modulated superimposed irradiation light.

The illumination light (irradiation light) generated by the light source 40 is guided by the first optical fiber 45 to the distal end portion 11A of the insertion portion 11, and spot-irradiated toward the subject via the lens 15A. The distal end portion 11A is provided with a scanning unit 15 which scans the irradiation light by changing the direction of the distal end of the first optical fiber 45 in accordance with a signal from the scanning control unit 25.

  The scanning unit 15 vibrates the tip of the first optical fiber 45 in the Y direction orthogonal to the X direction and the X direction. As a means for vibrating the first optical fiber 45, a method of attaching and vibrating a piezoelectric element to the first optical fiber 45, and an electromagnetic coil which causes a permanent magnet attached to the first optical fiber 45 to oscillate by an electromagnetic coil Use the method. When driving a first optical fiber 45 and driving a driving element such as a piezoelectric element or an electromagnetic coil in the vicinity of the resonance frequency of the first optical fiber 45, large deflection (displacement, amplitude) is obtained with small energy. Be

  The reflected light from the subject irradiated to the illumination light is condensed at the tip of the second optical fiber 46 via the lens 46A disposed at the tip 11A. The second optical fiber 46 guides the reflected light to the light receiving element 21. Each of the first optical fiber 45 and the second optical fiber 46 is composed of at least two optical fibers optically coupled to each other in the connector 14 or the like.

  In addition, as shown in FIG. 2, in the endoscope apparatus 1, one second optical fiber 46 is disposed at the distal end portion 11A, but in order to receive more reflected light, a plurality of The two optical fibers 46 may be disposed at the tip end portion 11A, multiplexed, and guided to the light receiving element 21.

  As shown in FIG. 3, in the endoscope apparatus 1, the irradiation light generated by the light source 40 includes an observation component for acquiring a two-dimensional image of the subject and a measurement component for measuring the subject. Here, the observation component includes red wavelength light which is a red wavelength component, green wavelength light which is a green wavelength component, and blue wavelength light which is a blue wavelength component in order to acquire a color image.

  The high frequency modulated red wavelength light has not only a function as a red wavelength component but also a function of a measurement component for performing distance measurement with the object using a time-of-flight method. In other words, red wavelength light is superimposed irradiation light in which the measurement component is superimposed on the observation component. That is, the red wavelength light which is an observation component of the irradiation light contains the measurement component by high frequency modulation. In FIG. 3 and the like, for convenience of illustration, modulated light such as red wavelength light is expressed in a state of being modulated at a frequency lower than the actual one.

  The R light source 41, the G light source 42, and the B light source 43 are surface sequential systems that emit light with a time difference. The irradiation light spot-irradiated on the subject is continuously scanned two-dimensionally. Therefore, strictly speaking, the place A irradiated with the red wavelength light, the place B irradiated with the green wavelength light, and the place C irradiated with the blue wavelength light are different. For this reason, so-called color breakup may occur, and one white straight line may be viewed as being divided into a red straight line, a green straight line, and a blue straight line. However, by switching RGB light fast enough, it is possible to process places A, B and C as the same place. The light amounts of the red wavelength light, the green wavelength light, and the blue wavelength light do not have to be the same.

  The tip of the first optical fiber 45 is scanned by the scanning unit 15 in the X and Y directions. As a scanning method, in order to illuminate a predetermined range uniformly, a spiral (spiral) method shown in FIG. 4A, a raster method shown in FIG. 4B or the like is used.

  For example, in the scanning method shown in FIGS. 4A and 4B, scanning with the R light source 41 as irradiation light is performed from A to B, and an image of a red field is acquired by the reflected light. Next, scanning using the G light source 42 as irradiation light is performed from A to B, and an image of a green field is acquired by the reflected light. Further, scanning with the B light source 43 as irradiation light is performed from A to B, and an image of a blue field is acquired by the reflected light. In the field sequential endoscope apparatus 1, one color image is obtained from the image of the red field, the image of the green field, and the image of the blue field.

  As shown in FIG. 5, the reflected light is composed of the observation component light (G component, B component) and the superimposed reflection light (R component) in which the measurement component is superimposed on the observation component, as in the illumination light.

  The light receiving element 21 made of silicon is a single visible light receiving element in which a single detection layer converts reflected light into an electric signal and outputs the electric signal. That is, the detection layer 21L of the light receiving element 21 shown in FIG. 6 detects light in the visible light range from the red wavelength to the blue wavelength. The light receiving element 21 is a photodiode that outputs an electrical signal D including an observation signal and a measurement signal based on the detected reflected light. The observation signal consists of R component, G component and B component. The R component is a superimposed observation signal in which the measurement component is superimposed on the observation signal, but the observation signal is extracted by integration.

  The signal processing unit 22 processes observation signals of three components of RGB and outputs two-dimensional color image data. The image generation unit 23 outputs a two-dimensional color image 30A as shown in FIG. 7 from the two-dimensional color image data. The two-dimensional color image 30A is an endoscopic image of a lumen in the body.

  Furthermore, the signal processing unit 22 processes the measurement component of the superimposed observation signal, that is, the high frequency modulation component, and outputs range image data as measurement data.

As shown in FIG. 8, the red wavelength component, which is a measurement component of the irradiation light for performing distance measurement using the time-of-flight method, is high frequency modulated to a frequency f. Assuming that the distance to the object is L, the reflected light has a time difference (delay) Δt with respect to the illumination light .

  Therefore, the distance L to the subject can be calculated by the following (formula 1). c is the speed of light.

2L = c × Δt (equation 1)
The distance L to the subject calculated from (Expression 1) is the length of the first optical fiber 45 (the distance from the light source 40 to the distal end 11A of the insertion portion 11 of the endoscope 10) L1 And a length L2 of the second optical fiber 46 (the distance from the tip 11A to the light receiving element 21). Since the distances L1 and L2 are constant, the signal processing unit 22 calculates distance image data based on the distance from the tip 11A to the subject.

  In the signal processing unit 22 that detects the phase difference Δφ of 1/1000 of the modulation frequency f, if the modulation frequency of the R light source 41 is 100 MHz to 1 GHz, distance measurement with a resolution of 1 mm or less becomes possible.

  The signal processing unit 22 outputs distance image data in which the distance to each spot-irradiated point of the subject is measured. The image generation unit 23 interpolates the distance image data, and outputs a distance image 30B as shown in FIG. The distance image 30B is an image at the same place as the two-dimensional color image 30A.

  Then, the image generation unit 23 generates a three-dimensional color image 30C shown in FIG. 10 from the two-dimensional color image 30A and the distance image 30B.

  The image generation unit 23 may generate the three-dimensional color image 30C from the two-dimensional color image data and the distance image data. When the monitor 30 can stereoscopically display, the three-dimensional image may not be mesh display according to the distance shown in FIG. 10 or the like, and may be a stereoscopic image including depth information.

  The endoscope apparatus 1 is configured because the light receiving unit is a single light receiving element 21 in which a single detection layer 21L outputs an electrical signal including an observation signal based on an observation component and a measurement signal based on a measurement component. Is easy.

  Furthermore, the R component which is an observation component of the illumination light is superimposed illumination light including the function of the measurement component. For this reason, a three-dimensional image can be acquired only with three light sources. Furthermore, since the irradiation light and the reflection light are visible light, the loss of light can be reduced by using an optical fiber having a high transmittance in the visible light band.

  In the above description, the R component is the superimposed illumination light, but the G component or the B component may be the superimposed illumination light, or a plurality of wavelength components, for example, the R component and the G component may be the superimposed illumination light. The R, G, and B components may be superimposed illumination light.

Modification of First Embodiment
Next, an endoscope apparatus 1X according to a modification of the first embodiment will be described. Since the endoscope apparatus 1X is similar to the endoscope apparatus 1, components having the same functions are denoted by the same reference numerals and the description thereof will be omitted.

  As shown in FIG. 11, a single light receiving element 21X made of silicon of the endoscope apparatus 1X has a plurality of detection layers 21L (red detection layer 21LR, green detection layer 21LG, and blue detection layer 21LB) laminated. It is a photodiode. Adjacent detection layers are doped with impurities of different polarities.

  The depth of the topmost blue detection layer 21LB is approximately 0.2 μm. The depth of the second green detection layer 21LG is about 0.6 μm. The depth of the lowermost red detection layer 21LR is about 2 μm.

  The light receiving element 21X forms three detection layers in the thickness direction of the element by utilizing the fact that the R component, the G component and the B component are different in the characteristics of transmitting silicon. The blue detection layer 21LB outputs a signal A based on the B component. The B component having a short wavelength does not reach the green detection layer 21LG. Thus, the green detection layer 21LG outputs a B observation signal based on the G component. Only the R component having a long wavelength reaches the red detection layer 21LR. Therefore, the red detection layer 21LR outputs a C observation signal based on the R component.

  As shown in FIG. 12, similarly to the illumination light, the reflected light is composed of the observation component light (G component, B component) and the superimposed reflection light (R component) in which the measurement component is superimposed on the observation component.

  When the light receiving element 21X receives the superimposed reflected light (R component), the blue detection layer 21LB outputs a signal A1, the green detection layer 21LG outputs a signal B1, and the red detection layer 21LR outputs a signal C1. Signal C1 is a superimposed observation signal based on the R component including the measurement component. The blue detection layer 21LB outputs a signal A1, and the green detection layer 21LG outputs a signal B1. The signals A1, B1 are not used for processing.

  When the light receiving element 21X receives G component light, the blue detection layer 21LB outputs a signal A2, and the green detection layer 21LG outputs a signal B2 based on the G component. The signal C2 output from the red detection layer 21LR is substantially zero of only the noise component. The signals A2, C2 are not used for processing.

  When the light receiving element 21X receives the B component light, the blue detection layer 21LB outputs a signal A3 based on the B component light. The signal B3 output from the green detection layer 21LG and the signal C3 output from the red detection layer 21LR are substantially zero of noise components only. Signals B3 and C3 are not used for processing.

  The light receiving element may output a signal between the silicon substrate and each detection layer, and the signal processing unit 22 may calculate the difference to obtain an electric signal based on each component.

  The observation signal consists of R component, G component and B component. The R component is a superimposed observation signal in which the measurement component is superimposed on the observation signal. The light receiving element 21X outputs an electrical signal including an observation signal and a measurement signal based on the detected reflected light.

  The endoscope apparatus 1X has the effect of the endoscope apparatus 1, and further, the light receiving element 21X is formed by laminating a plurality of detection layers 21L (red detection layer 21LR, green detection layer 21LG, and blue detection layer 21LB) Therefore, the detection sensitivity is higher than that of the light receiving element 21.

Second Embodiment
Next, an endoscope apparatus 1A according to a second embodiment will be described . Since the endoscope apparatus 1A is similar to the endoscope apparatus 1, components having the same functions are denoted by the same reference numerals and the description thereof will be omitted.

  As shown in FIG. 13, the light source 40A of the endoscope apparatus 1A includes an R light source 41, a G light source 42, a B light source 43, and an IR light source 44 that generates infrared light. The wavelength of the infrared light is, for example, 750 nm to 1600 nm, preferably 1400 nm or less, particularly preferably 1200 nm or less, since the reflected light is mainly reflected from the surface of the living tissue, the surface shape is good. You can get it.

  The light receiving element 21A is a wide band light receiving element in which a single detection layer 21LA converts light of a wide wavelength band from visible light to infrared light into an electric signal and outputs the electric signal.

  As shown in FIG. 14, the irradiation light generated by the light source 40A includes an observation component for acquiring a two-dimensional image of a subject and a measurement component for measuring the subject. Here, the observation component includes red wavelength light which is a red wavelength component, green wavelength light which is a green wavelength component, and blue wavelength light which is a blue wavelength component. The measurement component is a high frequency modulated infrared wavelength component generated by the IR light source 44.

  The R light source 41, the G light source 42, the B light source 43, and the IR light source 44 emit light with a time difference.

  As shown in FIG. 15, the reflected light is made up of an observation component (R component, G component, B component) and a measurement component (IR component) in the same manner as the illumination light.

  The light receiving element 21A detects light in a wide band from the visible light wavelength to the infrared wavelength. Then, the light receiving element 21A outputs an electrical signal including an observation signal and a measurement signal.

  The signal processing unit 22 processes the observation signal to output two-dimensional color image data, and also processes the measurement signal to output distance image data as measurement data. The image generation unit 23 generates a three-dimensional color image 30C from the two-dimensional color image data and the distance image data.

The endoscope apparatus 1A has the same effect as the endoscope apparatus 1. And observation component illumination light (R, G, B) and measurement component illumination light (IR) are light of another wavelength. Therefore, the intensity difference between the three observation signals of RGB is small, and the color reproducibility is better than that of the endoscope apparatus 1. Further, since the measurement component illumination light has a longer wavelength than the endoscope apparatus 1, the accuracy of distance measurement can be easily improved.

  As the first optical fiber 45 and the second optical fiber 46, a first core for guiding a red wavelength component, a green wavelength component and a blue wavelength component, and a second core for guiding an infrared wavelength component And a multi-core optical fiber may be used. The first core is made of a material that has low loss for the visible light component (RGB), and the second core is made of a material that has low loss for the infrared light component (IR).

  In the endoscope apparatus 1 of the first embodiment, the light receiving element 21A which is a wide band light receiving element may be used instead of the visible light detecting type light receiving element 21.

  In addition, the light source 40A includes, as infrared wavelength components, a first infrared wavelength component with a wavelength of more than 1200 nm, preferably more than 1400 nm, and a second infrared wavelength component with a wavelength of 1200 nm or less, preferably 1400 nm or less. May occur. A distance image 30B of the second infrared wavelength component having a wavelength of 1200 nm or less is a three-dimensional image of the surface of a living tissue. On the other hand, the distance image 30B of the first infrared wavelength component having a wavelength of more than 1200 nm is a three-dimensional image of several mm below the inside of the living tissue, for example, the surface. That is, by switching the wavelength of infrared light emitted by the light source 40A, for example, a distance image of a blood vessel inside the living tissue can be obtained.

Modification of Second Embodiment
Next, an endoscope apparatus 1AX according to a modification of the second embodiment will be described. The endoscope apparatus 1AX is similar to the endoscope apparatus 1A, so components having the same function are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 16, the light receiving element 21AX of the endoscope apparatus 1AX is a single element in which a plurality of detection layers 21LA are stacked. A plurality of detection layers 21LA includes a visible light detecting layer 21LA1 for outputting a signal D, and the infrared light detecting layer 21L A 2 for outputting a signal E based on the infrared wavelength components below the visible light detection layer 21L A 1, It consists of The visible light detection layer 21L A 1 detects light in the visible light range from the red wavelength to the blue wavelength. The depth of the infrared light detection layer 21L A 2 is about 5 μm. Only the infrared (IR) component having a long wavelength reaches the infrared light detection layer 21L A 2.

  As shown in FIG. 17, the reflected light is made up of an observation component (R component, G component, B component) and a measurement component (IR component), as with the illumination light.

  The visible light detection layer 21LA1 of the light receiving element 21AX outputs a signal D which is an observation signal (R signal, G signal, B signal). On the other hand, the infrared light detection layer 21LA2 outputs a signal E which is a measurement signal (IR signal).

  The endoscope apparatus 1AX has the effect of the endoscope apparatus 1A, and the light receiving element 21AX has higher detection sensitivity than the light receiving element 21A because a plurality of detection layers 21LA are stacked.

  In the endoscope apparatus 1AX, the visible light detection layer 21LA1 for receiving visible light (RGB) and the infrared light detection layer 21LA2 for receiving infrared light (IR) simultaneously output the signal D and the signal E. it can. For this reason, visible light and infrared light may be simultaneously irradiated. That is, the R light source 41, the G light source 42 or the B light source 43, and the IR light source 44 may simultaneously emit light. High-speed imaging is possible because it is not necessary to provide a time during which only IR light is emitted. Also, matching between the color image and the distance image is facilitated.

Third Embodiment
Next, an endoscope apparatus 1B according to a third embodiment will be described . Since the endoscope apparatus 1B is similar to the endoscope apparatus 1 and the like, components having the same functions are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 2 and 18, the light source 40B of the endoscope apparatus 1B has an R light source 41, a G light source 42, and a B light source 43, as in the light source 40 of the first embodiment. However, in the light source 40B, the R light source 41, the G light source 42, and the B light source 43 simultaneously emit light. That is, the illumination light is mixed light composed of the observation component light (G component, B component) and the superimposed illumination light (R component) in which the measurement component is superimposed on the observation component.

  The light receiving element 21B is a modulation type light receiving element that a single detection layer 21LB converts reflected light into an electric signal and outputs the electric signal. The light receiving wavelength band of the light receiving element 21B changes according to the intensity of the bias voltage applied to the detection layer 21LB. For example, when a bias is applied to the light receiving element 21B, which is a Schottky type detecting element, the Schottky barrier becomes smaller and the detectable wavelength shifts to the long wavelength side, so that the detection sensitivity to the wavelength changes.

  The light receiving element 21B outputs electric signals of three different strengths when predetermined three types of biases are applied via a mesh electrode or the like in the uppermost layer (not shown). Each electrical signal contains signals based on the three wavelength bands of R, G, and B at different rates.

  Since changes in detection sensitivity in the three wavelength bands due to bias application are known, signals from the three wavelength bands of R, G, and B can be calculated from three types of electrical signals.

  That is, as shown in FIG. 19, the light receiving element 21B sequentially outputs three types of electric signals A, B and C containing R component signals (superimposed), G component signals and B component signals at different ratios. . The signal processing unit 22 separates three observation signals of R, G and B from the three electric signals A, B and C, and acquires measurement signals. Note that the arithmetic unit of the light receiving unit including the light receiving element 21B may perform the signal separation process.

  The endoscope apparatus 1B has the same effect as the endoscope apparatus 1. Furthermore, in the endoscope apparatus 1B, since the measurement component and all the observation components are simultaneously irradiated to the subject, an observation image and a measurement image of the same time can be obtained. For this reason, the endoscope apparatus 1B has the effect of the endoscope apparatus 1 etc. Furthermore, there is no possibility that color breakup will occur, and matching of the two images is easier than the endoscope apparatus 1 etc. is there.

  In the endoscope apparatus 1B, the R light source 41, the G light source 42, and the B light source 43 simultaneously emit light, but the light receiving element 21B is a surface sequential method of sequentially receiving images of three fields of RGB . On the other hand, by changing the bias of the light receiving element 21B at high speed during one scan (between A and B in FIG. 4A etc.), an image of three fields of RGB and one distance during one scan A so-called simultaneous method of obtaining an image is also possible.

  In the simultaneous method, although it is necessary to modulate the bias at a high frequency, there is no possibility that color breakup occurs even if the subject is a rapidly changing object, and the accuracy of distance measurement is high.

  When the R light source 41, the G light source 42, and the B light source 43 sequentially emit light, the light receiving element 21B may switch the light reception wavelength in synchronization with the wavelength switching of the illumination light.

<Modification of Third Embodiment>
Next, an endoscope apparatus 1BX of a modified example of the third embodiment will be described. Since the endoscope apparatus 1BX is similar to the endoscope apparatus 1B, components having the same functions are denoted by the same reference numerals, and the description thereof will be omitted.

  As shown in FIG. 20, when the light receiving element 21X of the endoscope apparatus 1BX receives the reflected light composed of mixed light, the blue detection layer 21LB is a signal A, the green detection layer 21LG is a signal B, and the red detection layer 21LR is The signal C is output. The signal C is a superimposed observation signal based on the R component including the measurement component. The signal B is based on the R and G components including the measurement component. Signal B is based on R, G and B components including the measurement component.

  When the signal C is subtracted from the signal B, it becomes a green observation signal based only on the G component. When the signal B is subtracted from the signal A, it becomes a blue observation signal based on only the B component.

  The endoscope apparatus 1BX has the effect of the endoscope apparatus 1B, and since the light receiving element 21X simultaneously outputs the signals A, B, and C, the measurement component and all the observation components are simultaneously irradiated to the subject Therefore, an observation image and a measurement image of the same time can be obtained. Furthermore, since the time when the light receiving element 21X outputs the signals A, B, C is long in the endoscope apparatus 1BX, information with less noise can be obtained than in the endoscope apparatus 1B.

Fourth Embodiment
An endoscope apparatus 1C according to a fourth embodiment will now be described. Since the endoscope apparatus 1C is similar to the endoscope apparatuses 1 to 1B and the like, components having the same functions are denoted by the same reference numerals, and the description thereof will be omitted.

As shown in FIGS. 13 and 21, the light source 40C of the endoscope apparatus 1C has an R light source 41, a G light source 42, a B light source 43, and an IR light source 44, as the light source 40A of the second embodiment. . However, in the light source 40C, similarly to the light source 40B, the R light source 41, the G light source 42, the B light source 43, and the IR light source 44 simultaneously emit light. That is, the illumination light is mixed light composed of the observation component light (R component, G component, B component) and the measurement component light (IR component).

  As shown in FIG. 22, the wide band modulation type light receiving element 21C to which four types of biases are sequentially applied includes four types of R component signals, G component signals, B component signals and IR component signals at different ratios. The electric signals A, B, C, and D are sequentially output.

The signal processing unit 22 separates three observation signals of R, G, and B from four types of electric signals A, B, C, and D, and acquires measurement signals. The calculation means of the light receiving portion including a light receiving element 21 C may be carried out is signal separation processing.

  The endoscope apparatus 1C has the effects of the endoscope apparatus 1A and the effects of the endoscope apparatus 1B, and there is no risk of color breakup even with a subject that changes rapidly, and the accuracy of distance measurement is high.

  When the R light source 41, the G light source 42, the B light source 43, and the IR light source 44 sequentially emit light, the light receiving element 21B may switch the light reception wavelength in synchronization with the wavelength switching of the illumination light.

Modification of Fourth Embodiment
Next, an endoscope apparatus 1CX according to a modification of the fourth embodiment will be described. Since the endoscope apparatus 1CX is similar to the endoscope apparatus 1C, components having the same functions are denoted by the same reference numerals, and the description thereof will be omitted.

  As shown in FIG. 23, the light receiving element 21CX of the endoscope apparatus 1CX is a single element in which a plurality of detection layers 21LC are stacked. The plurality of detection layers 21LC include a visible light detection layer 21LC1 that outputs an observation signal, and an infrared light detection layer 21LC2 that outputs a measurement signal based on an infrared wavelength component.

  The upper visible light detection layer 21LC1 includes a red detection layer 21LR, a green detection layer 21LG, and a blue detection layer 21LB.

  The infrared light detection layer 21LC2 outputs a signal E based on an infrared wavelength (IR) component. The red detection layer 21LR outputs a signal C based on the R component. The green detection layer 21LG outputs a signal B based on the G component. The blue detection layer 21LB outputs a signal A based on the B component.

  As shown in FIG. 24, the light source 40C of the endoscope apparatus 1C has an R light source 41, a G light source 42, a B light source 43, and an IR light source 44, as the light source 40A of the second embodiment.

However, in the light source 40C, similarly to the light source 40B, the R light source 41, the G light source 42, the B light source 43, and the IR light source 44 simultaneously emit light. That is, the illumination light is mixed light composed of the observation component light (R component, G component, B component) and the measurement component light (IR component).

  As shown in FIG. 25, the light receiving element 21 </ b> CX that receives the reflected light composed of mixed light outputs four types of electrical signals A, B, C, and E. The electrical signals A, B and C are observation signals, and the signal E is a measurement signal.

  The endoscope apparatus 1CX has the effect of the endoscope apparatus 1C, and since the time for the light receiving element 21CX to output the signals A, B, C, and E is long, noise is more than that of the endoscope apparatus 1C. Less information can be obtained.

  In the endoscope apparatus 1CX, the visible light detection layer 21LC1 that receives visible light (RGB) and the infrared light detection layer 21LC2 that receives infrared light (IR) simultaneously have the signals A, B, or C and , E can be output. For this reason, visible light and infrared light may be simultaneously irradiated. That is, the R light source 41, the G light source 42 or the B light source 43, and the IR light source 44 may simultaneously emit light. High-speed imaging is possible because it is not necessary to provide a time during which only IR light is emitted. Also, matching between the color image and the distance image is facilitated.

  In the endoscope apparatus 1CX, similarly to the light source 40A of the second embodiment, the light source 41, the G light source 42, the B light source 43, and the IR light source 44 emit light with a time lag, It may be combined with 21C. At this time, as in the light source 40A, the R light source 41, the G light source 42 or the B light source 43, and the IR light source 44 may simultaneously emit light.

Fifth Embodiment
An endoscope apparatus 1D according to a fifth embodiment will now be described. Since the endoscope apparatus 1D is similar to the endoscope apparatuses 1 to 1 CX and the like, components having the same functions are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 25, in the endoscope device 1D, the light receiving element 21D is disposed at the distal end portion 11A of the insertion portion 11 of the endoscope 10. The light receiving element 21D is a single visible light receiving element which is the same as the light receiving element 21 and in which a single detection layer 21L converts reflected light into an electric signal and outputs the electric signal. The electrical signal output from the detection layer 21L is transmitted to the signal processing unit 22 via the signal line 21M.

In the endoscope apparatus 1D, the reflected light enters the light receiving element 21 D without passing through the second optical fiber. Therefore, the loss is small and the sensitivity is high. Further, since the influence of the time difference Δt caused by the length L2 of the second optical fiber 46 is eliminated, the accuracy of the distance measurement is higher.

  In the endoscope apparatus 1D, the reflected light enters the light receiving element 21 without passing through the second optical fiber. Therefore, the loss is small and the sensitivity is high. Further, since the influence of the time difference Δt caused by the length L2 of the second optical fiber 46 is eliminated, the accuracy of the distance measurement is higher.

  Also in the endoscope apparatuses 1A to 1CX, a small-sized light receiving element (light receiving unit) can be disposed at the distal end portion 11A of the insertion portion 11 of the endoscope 10. The light receiving element (light receiving unit) may be disposed in the holding unit 12B of the endoscope 10. Alternatively, the light source 40 may be disposed on the grip 12B.

  In the above description, distance measurement has been described as an example of measurement of a subject. However, as measurement of an object using irradiation light, calorific value (temperature) measurement using infrared irradiation light, distribution of water content by FI-IR method, or detecting fluorescence generated by irradiation light In this case, quantitative measurement of the corresponding component, Raman scattered light measurement, etc. may be used.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications, combinations, and applications are possible without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1, 1A-1DX ... Endoscope apparatus 10 ... Endoscope 15 ... Scanning part 20 ... Body part 21 ... Light receiving element 21L ... Detection layer 22 ... Signal processing part 23 ... image generation unit 24 ... control unit 25 ... scan control unit 30 ... monitor 30A ... two-dimensional color image 30B ... distance image 30C ... three-dimensional color image 40 ... · Light source 45 · · · First optical fiber 46 · · · Second optical fiber

Claims (8)

A light source for generating irradiated light;
A first optical fiber for spot-irradiating the guided light from the tip toward the object;
A scanning unit configured to scan the irradiation light by changing the direction of the tip of the first optical fiber;
A light receiving unit that outputs an electrical signal based on the reflected light from the object irradiated with the irradiation light;
An endoscope apparatus comprising: a signal processing unit configured to process the electrical signal;
The irradiation light is superimposed on an observation component for acquiring a two-dimensional image of the subject and the observation component, and high frequency modulation is performed to perform distance measurement with the subject using a time-of-flight method. Containing the measured components and
The light receiving unit outputs the electric signal including an observation signal based on the observation component of the reflected light and a measurement signal based on the measurement component of the reflected light;
An endoscope apparatus characterized in that the signal processing unit processes the observation signal and outputs two-dimensional image data, and processes the measurement signal and outputs measurement data. A second optical fiber for guiding the reflected light;
The endoscope apparatus according to claim 1, wherein the light receiving unit receives the reflected light guided by the second optical fiber.   The endoscope apparatus according to claim 1, wherein the light receiving unit is disposed at a tip end or a grip of the insertion unit of the endoscope. The observed component comprises a red wavelength component, a green wavelength component and a blue wavelength component,
The signal processing unit processes the observation signal and outputs color image data which is the two-dimensional image data, processes the measurement signal, and outputs distance image data as the measurement data.
The endoscope apparatus according to any one of claims 1 to 3, further comprising an image generation unit configured to generate a three-dimensional color image from the color image data and the distance image data. .   The endoscope apparatus according to claim 4, wherein the endoscope apparatus according to claim 4, wherein at least one of the red wavelength component, the green wavelength component, and the blue wavelength component is high-frequency modulated and is superimposed illumination light including the measurement component.   The endoscope apparatus according to claim 5, wherein the red wavelength component, the green wavelength component, and the blue wavelength component are sequentially emitted from the first optical fiber.   The endoscope apparatus according to claim 5, wherein the red wavelength component, the green wavelength component, and the blue wavelength component are simultaneously emitted from the first optical fiber.   The endoscope apparatus according to any one of claims 1 to 7, wherein the light receiving unit is a single light receiving element.

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