Endoscopic device

Abstract

This endoscope device includes: a bundle fiber 40 that has a base end 41 and a tip 42 and transmits a luminous flux incident from the base end 41 to the tip 42; a light source 71 that is arranged on the base end 41 side of the bundle fiber 40 and emits the luminous flux to be incident on the bundle fiber 40; a Ronchi ruling 150 that is arranged on the tip 42 side of the bundle fiber 40 and modulates the intensity distribution of the luminous flux emitted from the bundle fiber 40; and a control part that shifts an emission region 43 of the tip 42 of the bundle fiber 40 emitting the luminous flux incident on the Ronchi ruling 150 with respect to the bundle fiber 40 in the cross-sectional direction of the bundle fiber 40.

Description

Endoscopic Devices

[0001] The present disclosure relates to an endoscopic device.

[0002] Patent Document 1 describes an endoscopic technology for performing three-dimensional measurement by performing phase shift analysis on an image of an object onto which a structured pattern is projected.

[0003] U.S. Patent No. 7,812,968

[0004] The endoscope described in Patent Document 1 is provided with an imaging optical system (pattern imaging optical system) at the distal end of the fiber bundle in order to project a pattern formed at the output end of the fiber bundle onto an object. However, this configuration may make it difficult to reduce the size of the rigid portion at the distal end of the fiber bundle.

[0005] In view of the above circumstances, an object of one aspect of the present invention is to provide an endoscope apparatus that is capable of projecting a pattern while miniaturizing the tip portion of the endoscope.

[0006] An endoscopic device according to one aspect of the present invention includes a bundle fiber having a tip and a base end, which transmits a light beam incident from the base end to the tip, a light source arranged on the base end side of the bundle fiber and emitting a light beam to be incident on the bundle fiber, an intensity modulator arranged on the tip side of the bundle fiber and modulating an intensity distribution of the light beam emitted from the bundle fiber, and a control unit which shifts an emission area of ​​the tip of the bundle fiber, which emits the light beam to be incident on the intensity modulator, in a cross-sectional direction of the bundle fiber relative to the bundle fiber.

[0007] According to the above aspect, it is possible to provide an endoscope device that is capable of projecting a pattern while miniaturizing the tip portion of the endoscope.

[0008] 20. FIG. 21 is a diagram illustrating an external configuration of an endoscopic device according to an embodiment. FIG. 22 is a diagram illustrating an internal configuration of an endoscopic device. FIG. 23 is a diagram illustrating the configuration of a bundle fiber. FIG. 24 is a diagram illustrating a configuration for performing pattern illumination. FIG. 25 is a diagram illustrating a coordinate system and parameters based on the endoscopic device. FIG. 26 is an example of a flowchart of three-dimensional measurement processing. FIG. 27 is a diagram illustrating a change in light intensity distribution on an image plane due to a phase change of pattern illumination. FIG. 28 is a diagram illustrating an example of a method for calculating an initial phase. FIG. 29 is a diagram illustrating the relationship between the initial phase and coordinates. FIG. 29 is a diagram illustrating an example of the light intensity distribution of an object surface irradiated with pattern illumination. FIG. 29 is a diagram illustrating another example of the light intensity distribution of an object surface irradiated with pattern illumination. FIG. 29 is a diagram illustrating a modified example of the introduction optical system. FIG. 29 is a diagram illustrating yet another modified example of the introduction optical system. FIG. 29 is a diagram illustrating yet another modified example of the introduction optical system. FIG. 29 is a diagram illustrating yet another modified example of the introduction optical system. FIG. 29 is a diagram illustrating yet another modified example of the introduction optical system. 10A and 10B are diagrams showing modified examples of an introduction optical system, a bundle fiber, and a tip optical system.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a diagram illustrating an example of the external configuration of an endoscopic device 1 according to one embodiment. The endoscopic device 1 illustrated in Fig. 1 is used for endoscopic examinations in the industrial field and includes an insertion section 10, an operation section 20, and a main body section 30.

[0010] The insertion section 10 has an elongated shape that can be inserted into the inside of a test object (subject) such as a turbine or an engine, and has a tip section 11, a bending section 12 that is formed to be freely bendable, and a long flexible tube section 13. An optical adapter 14 is detachably attached to the tip section 11, as shown by the arrow.

[0011] The operation unit 20 has a joystick (bending operation) 21 that accepts an operation (bending operation) for bending the bending portion 12 in a desired direction, a plurality of buttons that accepts an operation for performing various inputs, and the like.

[0012] The main body 30 includes a display unit 31, an external interface 32, etc. The display unit 31 is a display device such as an LCD (Liquid Crystal Display), and displays various screens such as images of the inside of the subject and condition selection screens, and plays back and displays recorded videos. The display unit 31 also includes a touch panel 31a that accepts touch operations for various inputs. The touch panel 31a and the above-mentioned operation unit 20 are examples of an operation accepting unit that accepts operations by a user (examiner). The external interface 32 is connected to an external device such as an external storage device (for example, a USB (Universal Serial Bus) memory).

[0013] Fig. 2 is a diagram illustrating the internal configuration of the endoscope device 1 according to one embodiment. Fig. 3 is a diagram illustrating the configuration of the bundle fiber 40. Fig. 4 is a front view of the tip 10a of the insertion section 10. The internal configuration of the endoscope device 1 will be described below with reference to Figs. 2 to 4.

[0014] In the endoscopic device 1 illustrated in Figure 2, the optical adapter 14 attached to the tip portion 11 includes an illumination optical system 16, an objective optical system 17, and a pair of tip optical systems 15, and the tip portion 11 to which the optical adapter 14 is attached includes an image sensor 18.

[0015] The objective optical system 17 forms a subject image on the imaging element 18. The imaging element 18 captures (photoelectrically converts) the subject image formed by the objective optical system 17 to generate an imaging signal, which is output to an electrical circuit 90 of the main body 30 via a signal line 60. The imaging element 18 is a CCD (Charge Coupled Device) image sensor, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or the like.

[0016] Illumination light emitted from a light source 80 provided in the main body 30 enters the illumination optical system 16 via a light guide 50. The light source 80 is, for example, an LED (Light Emitting Diode). However, the light source 80 is not limited to an LED and may be, for example, an SLD (Super Luminescent Diode), an LD (Laser Diode), an ASE (Amplified Spontaneous Emission), a laser light source, or the like. The illumination optical system 16 irradiates the subject with the illumination light. Note that, although the present embodiment illustrates an example in which the light source 80 is provided in the main body 30, the light source 80 may also be provided in the insertion section 10 (for example, the distal end portion 11).

[0017] Illumination light emitted from an introduction optical system 70 provided in the main body 30 enters the distal optical system 15 via a bundle fiber 40. The distal optical system 15 irradiates the subject with illumination light for measuring the subject shape.

[0018] 3, the bundle fiber 40 has a base end 41 which is the end on the main body 30 side and a tip end 42 which is the end on the optical adapter 14 side, and transmits the light beam incident from the base end 41 to the tip end 42. The effective areas (effective areas 41a, 42a) for transmitting light of the bundle fiber 40 have an approximately rectangular shape on both the base end 41 side and the tip end 42 side.

[0019] The bundle fiber 40 is, for example, a bundle of multiple fibers each having a core and a cladding, but is not limited to this. The bundle fiber 40 may also be one in which multiple cores are covered with a single cladding. The material of the one or more fibers forming the bundle fiber 40 may be glass, plastic, or the like, but is not particularly limited and may be selected appropriately depending on factors such as heat resistance. The shape of the end of the bundle fiber 40 or the end of each of the multiple fibers is not limited to a rectangular shape and may be, for example, a circular shape.

[0020] The distal end optical system 15 forms a striped pattern in which the light intensity repeatedly increases and decreases along a predetermined direction on the subject using illumination light incident via the bundle fiber 40. That is, in the endoscope device 1, the introduction optical system 70, the bundle fiber 40, and the distal end optical system 15 constitute a pattern illumination device that illuminates the subject with a pattern. The detailed configuration of the pattern illumination device will be described later.

[0021] As shown in Figure 4, the pair of tip optical systems 15, illumination optical system 16, and objective optical system 17 provided in the optical adapter 14 are arranged at the tip 10a of the insertion section 10 so that the pair of tip optical systems 15 and illumination optical system 16 surround the objective optical system 17 on three sides at the center.

[0022] The main body 30 is provided with a processor 100 in addition to an introduction optical system 70, a light source 80, and an electrical circuit 90. The processor 100 is an example of a control unit that controls the endoscope device 1, and various processes such as illumination, imaging, and measurement are performed under the control of the processor 100.

[0023] Specifically, the processor 100 causes the image sensor 18 to capture an image of the subject illuminated with illumination light emitted from the illumination optical system 16, and causes the acquired image to be displayed on the display unit 31 of the main body 30. The processor 100 also causes the image sensor 18 to capture images of the subject illuminated in a pattern with illumination light emitted from the distal end optical system 15 multiple times while shifting the phase of the illumination pattern in response to a user operation, and analyzes the multiple captured images to measure the three-dimensional shape of the subject. Details of the measurement of the three-dimensional shape will be described later.

[0024] 5 is a diagram illustrating a configuration for performing pattern illumination. Hereinafter, the configuration for performing pattern illumination of the endoscope device 1 will be described in detail with reference to FIG.

[0025] In the endoscope device 1, the bundle fiber 40, the introduction optical system 70 arranged on the base end 41 side of the bundle fiber 40, and the tip optical system 15 arranged on the tip side of the bundle fiber 40, as shown in FIG. 5, constitute a pattern illumination device that provides pattern illumination to a subject.

[0026] The introduction optical system 70 includes a light source 71, a lens 72, a slit plate 73, and a drive mechanism 74. The light source 71 is disposed on the base end 41 side of the bundle fiber 40 and emits a light beam to be incident on the bundle fiber 40. The light source 71 is, for example, an LED. However, the light source 71 is not limited to an LED and may be a xenon lamp or the like. The lens 72 collimates the light beam emitted from the light source 71 and irradiates the base end 41 of the bundle fiber 40 with approximately uniform intensity.

[0027] The slit plate 73 is a plate in which a rectangular slit 73a is formed, and is disposed at the base end 41 of the bundle fiber 40. The slit plate 73 limits the light beam incident on the base end 41 of the bundle fiber 40 by blocking a portion of the light beam traveling from the lens 72 toward the base end 41. That is, the slit plate 73 is an intensity modulator disposed on the base end 41 side of the bundle fiber 40 that modulates the intensity distribution of the incident light beam, and limits the cross-sectional area of ​​the light beam passing through the slit plate 73. That is, by blocking a portion of the incident light beam and setting the intensity of the blocked portion to zero, the intensity distribution in a direction other than the normal direction to the surface of the base end 41 is modulated, and the light beam is converted into a light beam with a smaller cross-sectional area. Note that the cross-sectional area of ​​the light beam passing through the slit plate 73, i.e., the area of ​​the slit 73a, is smaller than the effective area 41a of the base end 41 of the bundle fiber 40.

[0028] The drive mechanism 74 is a drive mechanism that moves the slit plate 73 in the cross-sectional direction of the bundle fiber 40 (the direction crossing the bundle fiber 40), more specifically, in the short direction of the rectangular slit 73a, which is the cross-sectional direction crossing the bundle fiber 40. The drive mechanism 74 is not particularly limited, but is configured, for example, with a motor and a crank mechanism, a motor and a cam, etc. When the drive mechanism 74 moves the slit plate 73, the area within the effective area 41a of the base end 41 that is irradiated with the light beam (hereinafter referred to as the incident area) shifts in the cross-sectional direction of the bundle fiber 40.

[0029] The base end 41 and the tip 42 of the bundle fiber 40 are optically conjugate. Therefore, when the incident area shifts due to the movement of the slit plate 73, the area within the effective area 42a of the tip 42 from which the light beam is emitted (hereinafter referred to as the exit area 43) also shifts in the cross-sectional direction of the bundle fiber 40. The exit area 43 is an area from which the light beam is emitted to enter a Ronchi ruling 150, which will be described later.

[0030] Control of the operation of the drive mechanism 74 to move the slit plate 73 is an example of control of the introduction optical system 70 performed by the processor 100. That is, in the endoscope device 1, the processor 100 is configured to shift the emission area 43 of the tip 42 of the bundle fiber 40, which emits the light beam incident on the Ronchi ruling 150, in the cross-sectional direction of the bundle fiber 40 relative to the bundle fiber 40.

[0031] The tip optical system 15 includes a Ronchi ruling 150. As shown in FIG. 5 , the Ronchi ruling 150 has two regions with different transmittances arranged at a predetermined period. More specifically, the Ronchi ruling 150 is a plate in which light-shielding regions 152 are formed at a predetermined spatial frequency, and thereby transmissive regions 151 and light-shielding regions 152 are arranged alternately. The Ronchi ruling 150 is an example of an intensity modulator arranged on the tip 42 side of the bundle fiber 40, which modulates the intensity distribution of the light beam emitted from the bundle fiber 40. In other words, by blocking light that enters the light-shielding regions 152 out of the incident light beam and setting the intensity of the blocked portion to zero, the intensity distribution in a direction other than the normal direction of the surface of the base end 41 is modulated.

[0032] It is desirable that the direction in which the transmissive region 151 and the light-shielding region 152 are aligned (hereinafter simply referred to as the alignment direction) coincides with the movement direction of the slit plate 73, i.e., the direction in which the emission region 43 shifts. However, it is sufficient that the movement direction of the slit plate 73 has at least a component in the alignment direction.

[0033] In the pattern illumination device configured as described above, the light beam that enters bundle fiber 40 from introduction optical system 70 and then enters Ronchi ruling 150 of tip optical system 15 from introduction optical system 70 is periodically blocked by Ronchi ruling 150. As a result, as shown in Fig. 5, behind Ronchi ruling 150, there are formed: region D where the light beam emitted from exit region 43 is blocked by light-shielding region 152 and does not pass through at all; region B where the light beam emitted from exit region 43 passes entirely without being blocked by light-shielding region 152; and region M where part of the light beam emitted from exit region 43 is blocked by light-shielding region 152 and the rest passes through.

[0034] These regions form a unique stripe pattern on the subject surface according to the distance from the Ronchi ruling 150. The stripe pattern formed by the pattern illumination device is an illumination pattern in which the brightness repeatedly changes in the alignment direction in the order medium, dark, medium, light, medium, dark, medium, ... as shown in Fig. 5, and is an illumination pattern in which the light intensity repeatedly increases and decreases in a predetermined direction.

[0035] In this way, the endoscopic device 1 having the pattern illumination device can perform pattern illumination on a subject placed at the tip side of the insertion section 10 by modulating the intensity distribution of the light beam emitted from the emission area 43 using the Ronchi ruling 150.

[0036] In the endoscope device 1, the tip optical system 15 arranged on the tip side of the bundle fiber 40 only includes the Ronchi ruling 150, and there is no need to provide an imaging optical system consisting of one or more lenses. This makes it possible to reduce the size of the tip optical system 15, and ultimately to reduce the size of the optical adapter 14. Therefore, the endoscope device 1 can provide an endoscope device that is capable of pattern projection while miniaturizing the tip portion of the endoscope.

[0037] Furthermore, the endoscope device 1 having a pattern illumination device can shift the phase of the illumination pattern by having the processor 100 shift the emission area in the cross-sectional direction. The change in the illumination pattern caused by the phase shift also differs depending on the distance from the Ronchi ruling 150. Therefore, the endoscope device 1 can perform phase shift analysis using multiple images of the subject acquired by the processor 100 under multiple illumination conditions with different phases, and can measure the subject shape in three dimensions.

[0038] FIG. 6 is a diagram illustrating a coordinate system and parameters based on the endoscope device 1. FIG. 7 is an example of a flowchart of three-dimensional measurement processing. FIG. 8 is a diagram illustrating an example of a change in light intensity distribution on the image plane due to a phase change in pattern illumination. FIG. 9 is a diagram illustrating an example of a method for calculating an initial phase. FIG. 10 is a diagram illustrating an example of the relationship between the initial phase and coordinates. Hereinafter, three-dimensional measurement processing using pattern illumination performed by the endoscope device 1 will be described with reference to FIGS. 6 to 10.

[0039] First, a coordinate system and various parameters related to three-dimensional measurement processing will be described with reference to Fig. 6. The origin of the three-dimensional coordinate system based on the endoscope device 1 is a point on the optical axis AX of the tip of the objective optical system 17. The X and Y directions are directions perpendicular to each other on a plane perpendicular to the optical axis AX of the objective optical system 17, and the Z direction is a direction along the optical axis AX. Note that the Y direction is omitted from Fig. 6.

[0040] The coordinates of the three-dimensional measurement points are coordinates (X ｏｂｊ , Y ｏｂｊ , Z ｏｂｊ ) The three-dimensional measurement by the endoscope device 1 targets a limited range (measurement target range 110) from the tip of the objective optical system 17. The Z coordinate of the point closest to the objective optical system 17 and the Z coordinate of the point farthest from the measurement target range 110 are respectively represented by coordinates Z ｏｂｊ，ｎ , coordinate Z ｏｂｊ，ｆ is.

[0041] The X coordinate of the center of the effective area 42a of the tip 42 of the bundle fiber 40 is X ｐａ The width in the X direction of the emission area 43 formed in the effective area 42a is Hｅ The center of the emission area 43 is X ｐａ The width of the light-transmitting region 151 in the X direction is H. ｍｏｄ X ｍｏｄ，ｍ is the X coordinate of the center of the transmission area 151 of the Ronchi ruling 150, and m is a number (integer) that identifies the transmission area 151, assigned as 0, 1, 2 in order from the area closest to the optical axis AX.

[0042] The distance in the Z direction from the tip of the bundle fiber 40 to the Ronchi ruling 150 is L. The distance in the Z direction from the Ronchi ruling 150 to the tip of the objective optical system 17 is Z. ０ In addition, X ｅｃ is the shift amount of the Ronchi ruling 150 in the X direction from the reference position. f is the focal length of the objective optical system 17.

[0043] The three-dimensional measurement process shown in Figure 7 is started, for example, when the user inserts the insertion section 10 of the endoscope device 1 to a position where the measurement target portion within the subject is visible, and then performs a predetermined operation on the operation section 20.

[0044] The endoscope device 1 first illuminates a subject and captures an image of the subject (step S1). Here, the processor 100 causes the distal optical system 15 to illuminate the subject with illumination light in a pattern, and causes the imaging element 18 to capture the subject image formed by the objective optical system 17, thereby acquiring image data of the subject.

[0045] The endoscope device 1 determines whether a predetermined number of images for three-dimensional measurement have been taken (step S2), and if not (step S2 NO), shifts the phase of the illumination pattern (step S3) and performs illumination and imaging again (step S1).

[0046] In step S3, the processor 100 causes the driving mechanism 74 to move the slit plate 73, thereby shifting the exit area 43 in the cross-sectional direction of the bundle fiber 40, thereby shifting the phase of the illumination pattern, i.e., the phase of the spatial light intensity distribution on the subject.

[0047] 8(a) to 8(e) show the Z ｏｂｊ 8(f) to 8(j) show the light intensity distribution at each X coordinate of the image plane of the object at Z = 5 mm. ｏｂｊ 10 mm.

[0048] The horizontal axis of the graph in Fig. 8 represents the X coordinate on the image plane normalized by the focal length of objective optical system 17. The vertical axis of the graph in Fig. 8 represents the light intensity (intensity ratio) normalized to a maximum value of 1. Point P1 on the graph represents the intensity at a point on the image plane corresponding to the center of a specific transmission region 151, and point P2 on the graph represents the intensity at a point on the image plane corresponding to a point on the optical axis AX.

[0049] 8( a ) to 8 ( e ) and 8 ( f ) to 8 ( j ) are obtained by shifting the exit area 43 by 4 / p, and aligning the center of a certain transmission area 151 with the X-coordinate X ｐａ From the position shifted by -2 / p in the -X direction, the X coordinate X ｐａ 8 shows the light intensity distribution at each position when the slit plate 73 is moved by +2 / p in the +X direction from 1 / 1 to 1 / 2 in the +X direction. That is, Fig. 8 shows an example in which the processor 100 shifts the slit plate 73 by 4 / p using the drive mechanism 74 in step S2.

[0050] 8, focusing on point P1, it can be seen that shifting the emission region 43 by p shifts the illumination pattern by approximately one period. Also, focusing on point P2, focusing on point P2, it can be seen that the light intensity at a point on the image plane oscillates while shifting the emission region 43 by p. Therefore, by using the multiple image data acquired in steps S1 to S3 while moving the emission region 43 by approximately one period of the Ronchi ruling 150 pattern, it is possible to grasp how the light intensity at each point on the image plane changes.

[0051] When the predetermined number of imaging operations is completed (step S2: YES), the endoscope device 1 calculates the initial phase corresponding to each point on the image plane based on the acquired image data (step S4). ｉｍ , Y ｉｍ The initial phase corresponding to each point on the image plane is a specific phase of the illumination pattern, more specifically, the phase of the illumination pattern when the intensity of light incident on each point on the image plane reaches a maximum value while the phase is gradually shifted by one period.

[0052] In step S4, the processor 100 calculates an initial phase by estimating the phase at which the light intensity of the illumination pattern at each phase obtained from the multiple image data is maximized for each coordinate on the image plane.

[0053] 9A and 9B show the positions of the points (X ｉｍ 9(a) is a plot of the light intensity at the time when the object is Z ｏｂｊ 9(b) is a diagram when the object is at Z = 5 mm. ｏｂｊ 9 shows the position of the emission area 43, that is, the phase of the illumination pattern, and X ｐａ 9 is the amount of displacement normalized by the period p, with the maximum value being 1. The vertical axis of the graph shown in FIG.

[0054] When the light intensity of a point of interest on the image plane (in this example, a point corresponding to the optical axis AX) is plotted for each position of the emission region 43 (phase of the illumination pattern), an approximately triangular wave is formed, as shown in FIG. 9. Therefore, by approximating the triangular wave based on the plotted points, the peak value (maximum value) of the light intensity and the phase of the illumination pattern at that time, i.e., the initial phase, can be calculated. In FIG. 9(a), the initial phase R ｍａｘ =-0.409 is calculated, and in FIG. 9B, the initial phase R ｍａｘ = -0.109 is calculated.

[0055] Once the initial phase at each coordinate on the image plane is calculated, the endoscope device 1 calculates the three-dimensional coordinates of the object from the coordinates on the image plane and the initial phase (step S5). As described above, the change in the illumination pattern caused by the phase shift differs for each point in the three-dimensional space. Therefore, the coordinates (X ｉｍ , Y ｉｍ ) and the initial phase R that characterizes the change in the illumination pattern. ｍａｘ to the three-dimensional coordinates of the subject (X ｏｂｊ , Y ｏｂｊ , Z ｏｂｊ ) can be calculated.

[0056] In step S5, the processor 100 calculates the three-dimensional coordinates of the subject using the relationship between the combination of coordinates on the image plane and the initial phase, which is known because it is recorded in advance in the endoscope device 1, and the three-dimensional coordinates of the subject.

[0057] FIG. 10A shows the initial phase R ｍａｘ and the coordinates on the image plane (X ｉｍ , Y ｉｍ ) and the Z coordinate of the subject Z ｏｂｊ 10B is a graph showing the relationship between the initial phase R ｍａｘ and the X coordinate on the image plane (X ｉｍ , Y ｉｍ ) and the X coordinate of the subject ｏｂｊ 3 is a graph showing the relationship between the initial phase R ｍａｘ and the X coordinate on the image plane (Xｉｍ , Y ｉｍ ) and the Y coordinate of the subject ｏｂｊ These graphs can be created by repeatedly measuring the light intensity while shifting the phase of the illumination pattern using the endoscope device 1, with a specimen of a known shape placed at a known position.

[0058] As described above, the endoscope device 1 can perform phase shift analysis using multiple images of the subject and measure the subject shape in three dimensions by having the processor 100 perform the processing shown in Fig. 7. Therefore, the endoscope device 1 can perform pattern illumination with a configuration in which the tip of the endoscope is miniaturized, and can perform phase shift analysis to measure the subject shape in three dimensions.

[0059] A desirable configuration of the endoscope device 1 will be described below.

[0060] As described above, the phase shift analysis performed by the endoscope device 1 calculates the initial phase by utilizing the fact that light intensity fluctuates in a triangular wave shape when the illumination pattern is shifted. When the triangular wave shape formed by tracing the light intensity change becomes dull and the light intensity change near the peak becomes small, the accuracy of calculating the initial phase is likely to decrease. To shift the illumination pattern and generate a light intensity change in a sharp triangular wave shape, it is desirable that the light intensity distribution in the spatial direction also has a similar sharp triangular wave shape. To achieve the same sharp triangular wave shape for the light intensity distribution in the spatial direction, it is desirable that the endoscope device 1 satisfy the following conditional expression (1):

[0061] That is, the width H of the emission region 43 ｅ and the width H of the transmissive region 151 ｍｏｄ It is desirable that the difference between the width H of the emission region 43 is equal to or less than one tenth of the period p of the pattern of the Ronchi ruling 150. ｅ and the width H of the transmissive region 151 ｍｏｄ may be identical.

[0062] 11 to 13 are diagrams showing examples of light intensity distributions on an object surface illuminated with patterned illumination. FIG. 11 shows an example of a light intensity distribution when the width of the transmission region 151 is too large relative to the width of the emission region 43, resulting in a difference in their widths greater than one-tenth of the period. FIG. 11 also shows how the slope becomes smaller near the peak of the light intensity. FIG. 12 shows an example of a light intensity distribution when the difference in the width of the transmission region 151 and the width of the emission region 43 is sufficiently small, less than one-tenth of the period. FIG. 12 also shows a beautiful triangular wave with a sharp peak in the light intensity. FIG. 13 shows an example of a light intensity distribution when the width of the emission region 43 is too large relative to the width of the transmission region 151, resulting in a difference in their widths greater than one-tenth of the period. Like FIG. 11, FIG. 13 also shows how the slope becomes smaller near the peak of the light intensity.

[0063] 11 to 13 , satisfying conditional expression (1) allows the spatial light intensity distribution to have a sharp triangular shape. Therefore, when the endoscope device 1 satisfies conditional expression (1), it becomes possible to calculate the initial phase with high accuracy, and it becomes possible to measure the three-dimensional shape of the subject with high measurement accuracy.

[0064] As described above, the endoscope device 1 captures an image of the subject multiple times at different phases by shifting the illumination pattern by one period. In other words, it is desirable to shift the illumination pattern by at least one period at the measurement point on the subject. ｏｂｊ , Y ｏｂｊ , Z ｏｂｊ In order for the illumination pattern to shift by one period, it is desirable that the endoscope device 1 be provided with a Ronchi ruling 150 so as to satisfy the following conditional expression (2):

[0065] In addition, m and a in the conditional expression (2) ０ , p, the X coordinate of the m-th transmissive area 151 is expressed by the following formula: ０ is the phase shift amount of the center of the transmission area 151 of the Ronchi ruling 150 relative to the optical axis AX, and −½≦a ０ ≦1 / 2 (a ０is synonymous with the central coordinate of the transparent region corresponding to m=0.) p is the period of the transparent region 151 in the X-axis direction.

[0066] That is, the X coordinate of the center of the transmission area 151 located closest to the optical axis AX is a ０ Assuming this, it is desirable to configure Ronchi ruling 150 so that, among the transmission regions 151 arranged at a period p, the m-th transmission region 151 satisfies conditional expression (2). For example, if m=3 or 4 satisfies conditional expression (2), Ronchi ruling 150 should be configured to include at least the third and fourth transmission regions 151.

[0067] If the measurement target range 110 of the endoscope device 1 is determined in advance by specifications, the endoscope device 1 only needs to satisfy conditional formula (2) at its near point and far point. That is, the endoscope device 1 only needs to satisfy conditional formulas (3-1) and (3-2). Note that, like m, m' is an integer indicating the number of the transmission region 151. It is a variable used to distinguish between integers that satisfy the conditional formula at the near point and integers that satisfy the conditional formula at the far point.

[0068] By configuring Ronchi ruling 150 to satisfy conditional expressions (3-1) and (3-2), endoscope device 1 can shift the phase of pattern illumination by the amount required for phase shift analysis. Furthermore, since Ronchi ruling 150 can be configured to have transmission regions 151 with numbers specified by m and m' that satisfy conditional expressions (3-1) and (3-2), the size of Ronchi ruling 150 can be kept small.

[0069] Below, numerical examples based on experiments conducted by the inventors are described for reference. ｐａ =+2mm, -2mm, H ｅ = 0.1 mm Ronchi Ruling 150 (2 pieces) H ｍｏｄ =0.1mm, p=0.2mm, a ０ = 0 position, measurement range L = 1 mm, Z ０ = 0 mm, Z ｏｂｊ，ｎ = 5 mm, Z ｏｂｊ，ｆ=10mm Conditional expression (1) (H ｅ -H ｍｏｄ ) / p=0, and conditional expression (1) is satisfied. m and m' satisfying conditional expressions (3-1) and (3-2), m=8 and m'=9

[0070] The following describes modified examples of the endoscope device 1. First, modified examples of the introduction optical system 70 of the endoscope device 1 will be described.

[0071] Fig. 14 is a diagram showing a modified example of the introduction optical system 70. The endoscope device 1 may be provided with an introduction optical system 70a shown in Fig. 14 instead of the introduction optical system 70. The introduction optical system 70a differs from the introduction optical system 70 in that it includes a relay optical system 701 between the slit plate 73 and the fiber bundle 40. In other words, the slit plate 73 is disposed in a position optically conjugate with the base end of the fiber bundle 40.

[0072] The lens 72 and relay optical system 701 of the introduction optical system 70a constitute a Koehler illumination optical system that illuminates the base end of the bundle fiber 40. That is, the introduction optical system 70a is provided with a Koehler illumination optical system that illuminates the base end 41 of the bundle fiber 40 between the light source 71 and the bundle fiber 40. By providing the introduction optical system 70a with a Koehler illumination optical system, the focal lengths of the lens 72 and relay optical system 701 used in the Koehler illumination can be optimized, and light can be incident on the base end 41 of the bundle fiber 40 with an optimal NA.

[0073] Fig. 15 is a diagram showing another modified example of the introduction optical system 70. The endoscope device 1 may be provided with an introduction optical system 70b shown in Fig. 15 instead of the introduction optical system 70. The introduction optical system 70b differs from the introduction optical system 70 in that the lens 72 is omitted and the light source 71 is disposed close to the slit plate 73 and the bundle fiber 40.

[0074] Fig. 16 is a diagram showing yet another modified example of the introduction optical system 70. The endoscope device 1 may be provided with an introduction optical system 70c shown in Fig. 16 instead of the introduction optical system 70. The introduction optical system 70c differs from the introduction optical system 70 in that it includes a galvanometer mirror 702 and a controller 703 instead of the slit plate 73 and the drive mechanism 74, and in that it includes a lens 704.

[0075] The galvanometer mirror 702 is a scanner provided between the light source 71 and the bundle fiber 40, and is configured to shift the light beam incident on the bundle fiber 40 in the cross-sectional direction with respect to the bundle fiber 40. The controller 703 is a controller that controls the galvanometer mirror 702, and the processor 100 shifts the emission region 43 by controlling the galvanometer mirror 702 via the controller 703.

[0076] The lens 704 focuses the light beam collimated by the lens 72 onto the base end 41 of the bundle fiber 40. That is, in the introduction optical system 70c, the light source 71 and the base end of the bundle fiber 40 are conjugate with each other, and the intensity distribution of the light emitting surface of the light source 71 is projected onto the base end of the bundle fiber 40.

[0077] The introduction optical system 70c uses the galvanometer mirror 702, which allows the emission region 43 to be shifted faster than the driving mechanism 74, and is also excellent in durability.

[0078] Fig. 17 is a diagram showing yet another modified example of the introduction optical system 70. The endoscope device 1 may be provided with an introduction optical system 70d shown in Fig. 17 instead of the introduction optical system 70. The introduction optical system 70d differs from the introduction optical system 70 in that it includes a polygon mirror 705 and a controller 706 instead of the slit plate 73 and the drive mechanism 74, and in that it includes a lens 704.

[0079] The polygon mirror 705 is a scanner provided between the light source 71 and the bundle fiber 40, and is configured to shift the light beam incident on the bundle fiber 40 in the cross-sectional direction with respect to the bundle fiber 40. The controller 706 is a controller that controls the polygon mirror 705, and the processor 100 shifts the emission region 43 by controlling the polygon mirror 705 via the controller 706.

[0080] The lens 704 focuses the light beam collimated by the lens 72 onto the base end 41 of the bundle fiber 40. That is, in the introduction optical system 70d, the light source 71 and the base end of the bundle fiber 40 are conjugate with each other, and the intensity distribution of the light emitting surface of the light source 71 is projected onto the base end of the bundle fiber 40.

[0081] The introduction optical system 70d uses a polygon mirror 705, which allows the exit area 43 to be shifted at high speed by rotational movement.

[0082] Fig. 18 is a diagram showing yet another modified example of the introduction optical system. The endoscope device 1 may be provided with an introduction optical system 70e shown in Fig. 18 instead of the introduction optical system 70. The introduction optical system 70e differs from the introduction optical system 70 in that it includes a digital mirror device 707 and a controller 708 instead of the slit plate 73 and the drive mechanism 74, and in that it includes a relay optical system 701.

[0083] Digital mirror device 707 is an example of a second intensity modulator having a plurality of pixel elements that each modulates the intensity distribution of an incident light beam. Digital mirror device 707 is provided at a position optically conjugate with base end 41. Controller 708 controls the plurality of pixel elements of digital mirror device 707, and processor 100 shifts output region 43 by controlling the plurality of pixel elements via controller 708.

[0084] The relay optical system 701 projects an image of the digital mirror device 707 onto the base end 41. That is, in the introduction optical system 70e, the digital mirror device 707 and the base end of the bundle fiber 40 are conjugate with each other, and the intensity distribution on the digital mirror device 707 is projected onto the base end of the bundle fiber 40.

[0085] The introduction optical system 70e can shift the exit area 43 at high speed by using the digital mirror device 707. Even if there is a variation in the Ronchi ruling 150, it can be corrected by adjusting the width of the incident light beam on the digital mirror device 707 side. For example, ｍｏｄ If the value changes due to manufacturing variations, etc., the ON area of ​​the digital mirror device 707 is set to H ｍｏｄ By adjusting the ON region of the digital mirror device 707, it is possible to keep the value within the range of conditional expression (1). Furthermore, even if there is variation in the relay magnification of the relay optical system 701, this can be corrected by adjusting the ON region of the digital mirror device 707.

[0086] Fig. 19 is a diagram showing yet another modified example of the introduction optical system. The endoscope device 1 may be provided with an introduction optical system 70f shown in Fig. 19 instead of the introduction optical system 70. The introduction optical system 70f differs from the introduction optical system 70 in that a liquid crystal device 709 and a controller 710 are provided instead of the lens 72, the slit plate 73, and the drive mechanism 74.

[0087] The liquid crystal device 709 is an example of a second intensity modulator having a plurality of pixel elements each of which modulates the intensity distribution of the incident light beam. The liquid crystal device 709 is provided at the base end of the bundle fiber 40. More specifically, the liquid crystal device 709 is sandwiched between the light source 71 and the base end 41 of the bundle fiber 40.

[0088] The liquid crystal device 709 is composed of two polarizing plates 709a and 709c and a liquid crystal 709b sandwiched between them, and a controller 710 controls the state of the liquid crystal 709b in each pixel element to control the passage of light from the light source 71. The processor 100 controls the plurality of pixel elements of the liquid crystal device 709 via the controller 710 to shift the emission region 43.

[0089] The introduction optical system 70f can shift the exit area 43 at high speed without mechanical drive by using the liquid crystal device 709. Furthermore, even if there is variation in the Ronchi ruling 150, this can be corrected on the liquid crystal device 709 side by, for example, adjusting the width of the incident light beam.

[0090] Fig. 20 is a diagram showing yet another modified example of the introduction optical system. Fig. 21 is a diagram showing an example of light emission control of the multiple light sources shown in Fig. 20. The endoscope device 1 may be provided with an introduction optical system 70g shown in Fig. 20 instead of the introduction optical system 70. The introduction optical system 70g includes a light source unit 730 including multiple light sources (light sources 731 to 738), a switch 720 that controls the light source unit 730, and a fiber unit 740 that connects each light source included in the light source unit 730 to the proximal end 41 of the bundle fiber 40.

[0091] Each light source (light source 732, light source 733, light source 734, light source 735, light source 736, light source 737, light source 738) included in the light source unit 730 emits a light beam to each different fiber constituting the bundle fiber 40 via the fiber unit 740. The switch 720 controls the light emission periods (light emission periods T1 to T8 shown in FIG. 21 ) of the multiple light sources included in the light source unit 730.

[0092] The processor 100 shifts the emission region 43 by controlling the plurality of light sources via the switch 720. For example, as shown in FIG. 21 , the processor 100 may shift the emission region 43 little by little by shifting the light emission periods of adjacent light sources little by little.

[0093] Next, a modified example of the distal end optical system 15 of the endoscope device 1 will be described. Fig. 22 is a diagram showing a modified example of the distal end optical system. The endoscope device 1 may be provided with a distal end optical system 15a shown in Fig. 22 instead of the distal end optical system 15. The distal end optical system 15a differs from the distal end optical system 15 in that it includes a diffuser plate 160 for diffusing the light beam at the distal end 42 of the bundle fiber 40. Note that the diffuser plate 160 may be disposed between the distal end 42 of the bundle fiber 40 and the Ronchi ruling 150.

[0094] By providing the diffuser plate 160, it is possible to illuminate a wider range of the Ronchi ruling 150. This makes it possible to further expand the measurement target range.

[0095] Fig. 23 is a diagram showing another modified example of the distal end optical system. The endoscope device 1 may include a relay optical system 170 between the bundle fiber 40 and the Ronchi ruling 150, or the lenses constituting the relay optical system 170 may be disposed separately in the distal end of the insertion section 10 and in the optical adapter. For example, as shown in Fig. 23, a distal end section 11a including a part of the relay optical system 170 (lens 171) may be provided instead of the distal end section 11, and a distal end optical system 15b including the remainder of the relay optical system 170 (lens 172) may be provided instead of the distal end optical system 15.

[0096] With this configuration, an afocal light beam can be formed between the tip 11 and the optical adapter 14 (tip optical system 15b), so the length of the tip optical system 15b can be easily adjusted to match the objective optical system 17.

[0097] Although the relay optical system 170 is configured with a plurality of lenses, the relay optical system 170 may be configured with a single optical element such as a gradient index lens.

[0098] Fig. 24 is a diagram showing modified examples of the introduction optical system, the bundle fiber, and the distal end optical system. The endoscope device 1 may include an introduction optical system 70h shown in Fig. 24 instead of the introduction optical system 70, a bundle fiber 45 shown in Fig. 24 instead of the bundle fiber 40, and a distal end optical system 15c shown in Fig. 24 instead of the distal end optical system 15.

[0099] The introduction optical system 70h includes a laser light source 750 that emits laser light, a multimode optical fiber 760 into which the laser light emitted from the laser light source 750 is incident, an optical switch 770 having a plurality of connectors 771, and a bundle fiber 45 that bundles multimode optical fibers 44 connected to each connector 771.

[0100] The laser light source 750 is not particularly limited, but may be, for example, an LD (LASER Diode). The laser light emitted from the laser light source 750 enters an optical switch 770 disposed between the laser light source 750 and the bundle fiber 45 via a multimode optical fiber 760, and is output from the optical switch 770 to one of the multimode optical fibers 44 connected to one of the connectors 771. The core diameter and cladding diameter of each multimode optical fiber 44 are, for example, 105 μm and 125 μm, respectively.

[0101] The fiber bundle 45 is formed by bundling together multimode optical fibers 44, each connected to a different connector 771 of the optical switch 770. At the output end 46 of the fiber bundle 45, two rows of multimode optical fibers are arranged close to each other in a staggered manner, as shown in FIG. 24 . More specifically, each multimode optical fiber row is composed of a plurality of multimode optical fibers 44 aligned in the X-axis direction, and the two rows of multimode optical fibers are overlapped in the Y-axis direction with one row of multimode optical fibers shifted in the X-axis direction relative to the other row of multimode optical fibers by the radius of the multimode optical fibers 44. The X-axis and Y-axis directions are perpendicular to the Z-axis direction along the optical axis of the objective optical system 17 (not shown). The X-axis direction is the alignment direction of the transmission regions 151 and the light-blocking regions 152 of the Ronchi ruling 150, and the Y-axis direction is perpendicular to the X-axis direction.

[0102] The distal end optical system 15c is provided in the optical adapter 14b attached to the distal end 11c. Parallel plate glasses 191 and 192 are provided at the respective ends where the distal end 11c and the optical adapter 14b come into contact. This prevents dust and other particles from entering the interior when the optical adapter 14b is removed from the distal end 11c. The optical adapter 14b is similar to the optical adapter 14 in that it includes a Ronchi ruling 150, which is an intensity modulator arranged at the distal end of the bundle fiber 45 and modulates the intensity distribution of the light beam emitted from the bundle fiber 45. The optical adapter 14b further includes a concave lens 180, located downstream of the Ronchi ruling 150, that expands the light beam that has passed through the Ronchi ruling 150.

[0103] Even in the configuration of this modified example configured as described above, the light beam that enters the bundle fiber 45 from the introduction optical system 70h and then enters the Ronchi ruling 150 of the distal end optical system 15c is modulated by being periodically blocked by the Ronchi ruling 150. Therefore, a unique stripe pattern can be formed on the object surface depending on the distance from the Ronchi ruling 150. Furthermore, by controlling the optical switch 770 so that the processor 100 switches the selected connector 771, i.e., the connector 771 that outputs the laser light, it is possible to shift the output region; more specifically, to change the output position at the output end 46 of the bundle fiber 45 in the Y-axis direction. In other words, the selection of the connector 771 by the optical switch 770 acts in the same way as the shifting of the slit plate 73 by the drive mechanism 74. The change in the illumination pattern caused by such a phase shift also differs depending on the distance from the Ronchi ruling 150. Therefore, even in the configuration of this modified example, the endoscopic device 1 can perform phase shift analysis using multiple images of the subject acquired by the processor 100 under multiple lighting conditions with different phases, and can measure the subject shape in three dimensions.

[0104] Furthermore, in the configuration of this modification, a laser light source 750 is used as the light source. Although the optical fiber to which the laser light emitted from the laser light source 750 is guided is appropriately selected by the optical switch 770, the laser light is guided through the multimode optical fiber connected in series before being emitted toward the Ronchi ruling 150. In other words, the laser light is irradiated onto the Ronchi ruling 150 while maintaining high brightness. This makes it possible to form a high-contrast illumination pattern, enabling measurement of the object with higher accuracy. Furthermore, in the configuration of this modification, a concave lens 180 is provided downstream of the Ronchi ruling 150 to expand the light beam whose intensity distribution has been modulated by the Ronchi ruling 150, thereby compensating for the lack of NA of the multimode optical fiber 44. This allows adjustments to be made so that the illumination pattern is formed over an area of ​​appropriate size. Therefore, the configuration of this modification enables three-dimensional measurement of an object with high accuracy while ensuring a certain degree of object size that can be measured at one time.

[0105] The above-described embodiments are illustrative examples provided to facilitate understanding of the invention. The present invention is not limited to the above-described embodiments, and should be understood to encompass various modifications and alternative forms of the above-described embodiments. For example, it will be understood that the above-described embodiments can be embodied by modifying the components without departing from the spirit of the invention. It will also be understood that various embodiments can be implemented by appropriately combining multiple components disclosed in the above-described embodiments. Furthermore, it will be understood by those skilled in the art that various embodiments can be implemented by deleting some components from all of the components shown in the embodiments, or by adding some components to the components shown in the embodiments.

[0106] For example, in the above-described embodiment, the Ronchi ruling 150 in which the transmission regions 151 and the light-shielding regions 152 are alternately arranged is exemplified as an example of the intensity modulator arranged on the tip side of the bundle fiber 40, but it is desirable that the intensity modulator has at least two regions with different transmittances arranged at a predetermined period, and it may be composed of three or more regions with different transmittances. Also, the intensity modulator may include a region in which the transmittance changes continuously.

[0107] For example, in the above-described embodiment, an example has been shown in which the emission region 43 is restricted by arranging the slit plate 73 on the base end side of the bundle fiber 40, but the slit plate 73 may be arranged between the light source 71 and the Ronchi ruling 150, for example, on the base end side of the bundle fiber 40. The slit plate 73 arranged on the base end side may be driven by the drive mechanism 74 to shift the emission region 43.

[0108] 1: Endoscope device 40, 45: Fiber bundle 41: Base end 42: Tip 43: Emission area 71: Light source 73: Slit plate 74: Driving mechanism 100: Processor 150: Ronchi ruling 151: Transmitting area 152: Light-shielding area

Claims

1. An endoscope device comprising: a bundle fiber having a tip and a base end, and transmitting a light beam incident from the base end to the tip; a light source arranged on the base end side of the bundle fiber, and emitting the light beam to be incident on the bundle fiber; an intensity modulator arranged on the tip side of the bundle fiber, and modulating the intensity distribution of the light beam emitted from the bundle fiber; and a control unit that shifts an emission area of ​​the tip of the bundle fiber, which emits the light beam to be incident on the intensity modulator, in a cross-sectional direction of the bundle fiber relative to the bundle fiber.

2. An endoscope device according to claim 1, characterized in that the intensity modulator has at least two regions with different transmittances arranged at a predetermined period.

3. An endoscope device according to claim 1 or claim 2, further comprising: a second intensity modulator that modulates the intensity distribution of the incident light beam, the second intensity modulator being provided at the base end or at a position optically conjugate with the base end, and that limits the cross-sectional area of ​​the light beam passing through; and a drive mechanism that moves the second intensity modulator in the cross-sectional direction, wherein the control unit controls the drive mechanism to shift the emission area in the cross-sectional direction relative to the bundle fiber.

4. An endoscope device according to claim 3, further comprising a Kohler illumination optical system arranged between said light source and said bundle fiber for illuminating said base end.

5. An endoscope device according to claim 1 or claim 2, further comprising a scanner provided between the light source and the bundle fiber, which shifts the light beam incident on the bundle fiber in the cross-sectional direction relative to the bundle fiber, and wherein the control unit controls the scanner to shift the emission region in the cross-sectional direction relative to the bundle fiber.

6. An endoscope device according to claim 1 or claim 2, further comprising a second intensity modulator provided at the base end or at a position optically conjugate with the base end, the second intensity modulator having a plurality of pixel elements each of which modulates the intensity distribution of an incident light beam, and the control unit controls the plurality of pixel elements to shift the emission region in the cross-sectional direction relative to the bundle fiber.

7. An endoscope device according to claim 1 or claim 2, further characterized in that the light source comprises a plurality of light sources, each of which emits a light beam to a different fiber constituting the fiber bundle, and the control unit controls the plurality of light sources to shift the emission region in the cross-sectional direction relative to the fiber bundle.

8. An endoscope device according to claim 1 or 2, further comprising a diffusion plate for diffusing the light beam, disposed between said intensity modulator and said bundle fiber.

9. An endoscope device according to claim 1 or claim 2, further comprising: an insertion section having an image sensor and to be inserted into a subject; and a main body section to which said insertion section is connected, wherein said bundle fiber and said intensity modulator are provided in said insertion section, and said light source is provided in said main body section.

10. An endoscope device according to claim 1 or claim 2, further comprising: an insertion section having an image sensor and to be inserted into a subject; a main body section to which said insertion section is connected; and an optical adapter that is detachably attached to the tip of said insertion section, wherein said bundle fiber is provided in said insertion section, said intensity modulator is provided in said optical adapter, and said light source is provided in said main body section.

11. An endoscope device according to claim 2, wherein the intensity modulator has transmission areas and light blocking areas arranged at the predetermined period in the cross-sectional direction, and the width of the emission area in the cross-sectional direction is set to H ｅ and the width of the transmission area in the cross-sectional direction is H ｍｏｄ and the predetermined period is p, the endoscope apparatus satisfies the following conditional expression:

12. The endoscope device according to claim 2 further comprises an objective optical system that forms an image of the subject illuminated with a light beam modulated by the intensity modulator, the intensity modulator having transmission areas and light blocking areas arranged at the predetermined period in the cross-sectional direction, the distance in the optical axis direction of the objective optical system from the tip of the bundle fiber to the intensity modulator being L, and the distance in the optical axis direction from the intensity modulator to the tip of the objective optical system being Z ０ and the coordinate of the near point of the measurement target area in the optical axis direction is Z ｏｂｊ，ｎ and the coordinate of the far point of the measurement target area in the optical axis direction is Z ｏｂｊ，ｆ When the transmission regions are arranged at the predetermined period, the transmission region closest to the optical axis of the objective optical system is numbered as the 0th transmission region, and the numbers of the transmission regions are m and m', and the phase shift amount of the center of the transmission region of the intensity modulator with respect to the optical axis is a ０ The coordinate of the center of the effective area of ​​the tip of the bundle fiber in the cross-sectional direction is X ｐ and the intensity modulator is configured to have m-th and m'-th transmission regions that satisfy the following conditional expression:

13. An endoscope device according to claim 1 or 2, further comprising an optical switch arranged between the light source and the bundle fiber, wherein the light source is a laser light source, the bundle fiber includes a plurality of multimode optical fibers each connected to a different connector of the optical switch, and the control unit shifts the emission area by controlling the optical switch to switch the selected connector.

14. An endoscope apparatus according to claim 13, further comprising a concave lens for expanding the light beam whose intensity distribution has been modulated by said intensity modulator.

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