JP6789710B2 - Imaging device - Google Patents

Description

The present invention relates to an imaging device suitable for acquiring an image of an object to be inspected, particularly a tomographic image.

At present, an optical coherence tomography (OCT) device (hereinafter referred to as an OCT device) using interference by low coherence light has been put into practical use. This makes it possible to acquire a tomographic image of an object to be inspected such as an eye with high resolution and non-invasively. Therefore, the OCT device is becoming an indispensable device for obtaining a tomographic image of the fundus of the eye to be inspected, especially in the field of ophthalmology. In addition to the field of ophthalmology, attempts have been made to observe tomographic images of the skin, configure an OCT device as an endoscope or a catheter, and take a tomographic image of the walls of the digestive and circulatory organs.

Here, in an OCT apparatus in the field of ophthalmology, there is a possibility that a tomographic image may be displaced due to the movement of the eye to be inspected during acquisition of an image, so that the imaging time is required to be shortened. Therefore, as an OCT device with improved measurement speed, an OCT device using a wavelength sweep light source (Swept Source OCT device, hereinafter referred to as SS-OCT device) has been actively developed. Patent Document 1 discloses an example of the configuration of the SS-OCT apparatus, and exemplifies a light source using a fiber ring resonator and a wavelength selection filter as a wavelength sweep light source.

On the other hand, since it is necessary to install a plurality of medical devices in a medical field, it is desired to make each device as small as possible. At this time, if the OCT device is simply miniaturized, the space inside the housing of the device is reduced, so that the distance between the members is shortened. Therefore, the influence of the heat generated by the wavelength sweep light source on the optical system and the like (decrease in alignment accuracy of the optical fiber end with respect to the optical axis due to thermal expansion and thermal displacement, etc.) cannot be ignored. In Patent Document 2, a laser light source having a large calorific value and an optical system are thermally isolated via an optical fiber as in the wavelength sweep light source, and the laser light source is fixed to a housing to suppress the influence of heat generation of the laser light source. The laser surveying device is disclosed. As disclosed in Patent Document 2, the heat rise of the optical system can be suppressed by thermally isolating the laser light source serving as a heat source and the optical system and separating the two configurations to some extent via an optical fiber. More specifically, the laser light source and the optical system are each built in a housing such as a case, and the housings are arranged apart from each other to suppress heat transfer from the laser light source to the optical system. By adopting such a configuration, the thermal influence from the laser light source on the optical system can be suppressed to some extent.

Japanese Unexamined Patent Publication No. 2012-115578 Japanese Unexamined Patent Publication No. 9-11372

However, the heat generated by the laser light source raises the temperature of the housing itself containing the laser light source, and the heat generated by the housing also raises the temperature of the gas around it. Therefore, it is inevitable that the temperature inside the housing containing all of these configurations will rise with the passage of time due to the heat generated from the laser light source. Therefore, the heat derived from the laser light source is transferred to the housing containing the optical system by dissolving the gas around it. From the above, in order to suppress the temperature rise of the optical system, it is preferable that the configuration is further improved.

The present invention has been made in view of the above circumstances, and provides an imaging apparatus capable of reducing a temperature rise of an optical system while having a light source having a large calorific value inside.

In order to achieve the above object, the imaging device according to one embodiment of the present invention is
The subject is based on the interference light obtained by combining the return light obtained by irradiating the object to be inspected with the measurement light separated from the light emitted from the light source and the reference light separated from the light. An imaging device that acquires an image of an inspection object.
A first housing containing the light source and having a gas inlet and outlet,
A second housing containing at least a part of the reference light optical system and
A third housing containing the first housing and the second housing and having a vent for gas to flow in and an exhaust opening for gas to flow out.
A duct that communicates the outlet and the exhaust opening,
The gas flows into the inside of the third housing from the ventilation port, flows into the inside of the first housing from the inflow port through the periphery of the second housing, and flows into the inside of the first housing from the inflow port. It is characterized by including a fan for forming a flow of the gas so as to be discharged from the inside of the body through the outlet and the exhaust opening.

The image pickup apparatus according to the present invention can reduce the temperature rise of the optical system while having a light source having a large calorific value inside.

It is the schematic which shows the structure of the SS-OCT apparatus which concerns on one Example of this invention. It is the schematic which shows the structure of the reference optical system of the SS-OCT apparatus shown in FIG. It is a figure which shows the heat source in the housing, the flow of the cooling gas, and the positional relationship of each optical system in the SS-OCT apparatus which concerns on one Example of this invention.

Hereinafter, exemplary examples for carrying out the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative positions of the components, etc. described in the following examples are arbitrary and can be changed according to the configuration of the device to which the present invention is applied or various conditions. Also, in the drawings, the same reference numerals are used between the drawings to indicate elements that are the same or functionally similar.

A schematic configuration of the SS-OCT apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. The SS-OCT apparatus is an imaging apparatus having a wavelength sweep light source having a large calorific value inside. Further, with reference to FIG. 3, the heat source in the housing, the flow of the cooling gas, and the positional relationship of each optical system in the SS-OCT apparatus will be described.

FIG. 1 shows a schematic configuration of an SS-OCT apparatus according to an embodiment of the present invention. The SS-OCT device 1 includes a light source unit 10, a light amount adjusting optical system 20, an interference unit 30, a measuring optical system 40, a reference optical system 50, a detection unit 60, an information acquisition unit 70, and a display unit 80. The light source unit 10 emits light separated into measurement light and reference light, which will be described later. The light amount adjusting optical system 20 adjusts the light amount of the light emitted from the light source unit 10. The interference unit 30 generates interference light from the return light from the eye E to be measured and the reference light of the measurement light. The measurement optical system 40 irradiates the eye E to be measured with the measurement light, and emits the return light from the eye E to the interference unit 30. The reference optical system 50 adjusts the optical path length of the reference light that interferes with the return light emitted from the measurement optical system 40, and emits the adjusted reference light. The detection unit 60 detects the interference light, and the information acquisition unit 70 acquires the fundus information of the eye E to be inspected from the detected interference light. The display unit 80 displays the information acquired by the information acquisition unit 70.

Here, the form in which the information acquisition unit 70 and the display unit 80 are included in the SS-OCT device 1 and integrated with each other is illustrated. However, the information acquisition unit 70 and the display unit 80 may be configured separately from the SS-OCT device, and data or information may be exchanged between them by wire or wirelessly. Further, in each of the above-described configurations, the operation of each is controlled by a control means (not shown).

In this embodiment, the light source unit 10 includes a wavelength sweep light source 100, an optical fiber coupler 101, and a clock generation unit 102. The wavelength sweep light source 100 is a light source having a large calorific value in this embodiment, and sweeps the wavelength of the emitted light. The optical fiber coupler 101 propagates the light emitted from the wavelength sweep light source 100 through the optical fiber, and separates the light into light incident on the light amount adjusting optical system 20 and light incident on the clock generation unit 102. The clock generation unit 102 generates a clock signal based on the light from the incident light source, and sends the clock signal to the detection unit 60.

As the wavelength sweep light source 100, any light source can be used as long as it is a light source capable of sweeping the wavelength of the emitted light. Therefore, the wavelength sweep light source 100 may be, for example, a light source using the fiber ring resonator described in Patent Document 1 and a wavelength selection filter, or another commercially available wavelength sweep laser or the like. .. Further, the optical fiber coupler 101 may use a beam splitter or the like. The same applies to the replacement with a beam splitter or the like for other optical fiber couplers described in the following configurations.

The light amount adjusting optical system 20 includes a first light amount adjusting means 202, an optical fiber coupler 200, and a light amount measuring means 201. The light emitted from the light source unit 10 and guided by the optical fiber reaches the optical fiber coupler 200 via the first light amount adjusting means 202. The light is further separated by the optical fiber coupler 200 into light incident on the interference unit 30 and light incident on the light amount measuring means 201. The light amount measuring means 201 measures the light amount of the incident light, and the control means (not shown) uses the first light amount adjusting means 202 to adjust the light amount so that the measured light irradiated to the eye E to be examined has an appropriate light amount. Do. The details of the first light amount adjusting means 202 will be omitted here because they have the same configuration as the second light amount adjusting means 51 described later.

The interference unit 30 has an optical fiber coupler 300 and an optical fiber coupler 301. The optical fiber coupler 300 is connected to the optical fiber coupler 200, the optical fiber coupler 301, the measurement optical system 40, and the reference optical system 50 via an optical fiber. The optical fiber coupler 300 separates the light emitted from the light amount adjusting optical system 20 and guided by the optical fiber into a measurement light incident on the measurement optical system 40 and a reference light incident on the reference optical system 50.

The measurement light is applied to the eye E to be inspected via the measurement optical system 40. The return light of the measurement light after being reflected or scattered by the eye E to be inspected passes through the measurement optical system 40 again and reaches the optical fiber coupler 300. The return light enters the optical fiber coupler 301 via the optical fiber. On the other hand, the reference light enters the optical fiber coupler 301 via the reference optical system 50 and the optical fiber connecting the reference optical system 50 and the optical fiber coupler 301. The return light and the reference light incident on the optical fiber coupler 301 interfere with each other in the optical fiber coupler 301 to become interference light. The optical fiber coupler 301 functions as a wave combining means for obtaining interference light by combining the return light and the reference light. The generated interference light is separated in the optical fiber coupler 301 into two lights having different phases, in which the phase of one light is inverted from the phase of the other light, and the separated light is separated from each other in the optical fiber. It is guided to the detection unit 60 via. The configuration for obtaining the interference light is not limited to the embodiment exemplified here, and various other known interference systems can be used.

The measurement optical system 40 includes a lens 400, a focusing lens 401, an X scanner 402, a Y scanner 403, and an objective lens 404. The measurement light incident on the measurement optical system 40 from the interference unit 30 via the optical fiber is made parallel light by the lens 400. The focusing lens 401 is for focusing the measurement light on the eye E to be inspected, and can be moved in the optical axis direction by a driving unit (not shown). By this focusing, the return light from the eye E to be inspected is simultaneously imaged in a spot shape on the tip (ferrule) of the optical fiber from which the measurement light is emitted.

The X scanner 402 and the Y scanner 403 are each composed of galvanometer mirrors whose rotation axes are arranged so as to be orthogonal to each other, and both scanners can scan the measurement light on the eye E to be inspected. The X scanner 402 scans the measurement light in the X direction on the eye E to be inspected, and the Y scanner 403 scans the measurement light in the Y direction on the eye E to be inspected. The measurement light passes through the objective lens 404 arranged to face the eye E to be inspected and is irradiated to the eye E to be inspected. The measurement light applied to the eye E to be inspected is reflected as backscattered light on the fundus, for example. The reflected light from the fundus of the eye passes through the measurement optical system 40 again as the return light described above, and enters the interference portion 30 via the optical fiber.

The detection unit 60 includes a detector 600 and an A / D converter 601. The detector 600 detects the above-mentioned two interference lights propagated from the interference unit 30 via the optical fiber. Further, the detector 600 generates an interference signal based on the detected interference light and sends the interference signal to the A / D converter 601. The clock generation unit 102 described above is connected to the A / D converter 601. The A / D converter 601 samples the interference signal in synchronization with the clock signal sent from the clock generation unit 102 and converts it into a digital signal. The interference signal converted into a digital signal by the A / D converter 601 is sent to the information acquisition unit 70.

The information acquisition unit 70 performs frequency analysis such as Fourier transform on the digital signal received from the detection unit 60 to obtain information on the eye E to be inspected. Further, the information acquisition unit 70 detects the differential of the interference signal by taking the difference between the two interference signals based on the two interference lights having different phases detected by the detector 600, and detects the differential of the interference signal, and the eye to be inspected E in the interference signal. The signal-to-interference component signal ratio (S / N ratio) of the information can be reduced. The information acquisition unit 70 sends the obtained information on the eye to be inspected E to the display unit 80. The information acquisition unit 70 may be configured in the SS-OCT device 1 as an arbitrary information processing unit equipped with a CPU, an MPU, or the like, or may be configured by using a general-purpose computer.

The display unit 80 displays the received information as a tomographic image. The display unit 80 may be a monitor provided in the SS-OCT device 1 or an individual monitor connected to the SS-OCT device 1.

With the above configuration, the SS-OCT apparatus 1 can acquire information on the tomography of the eye E to be inspected, for example, at one point on the fundus. In this way, irradiating the one point of the eye E to be inspected with the measurement light to acquire the tomographic information in the depth (Z) direction of the eye E to be inspected is called A scan. By scanning the measurement light so that the A scan is continuously performed in the transverse direction of the eye E to be inspected, it is possible to acquire two-dimensional tomographic information including the transverse direction and the depth direction of the eye E to be inspected. it can. Scanning of the measurement light for obtaining this two-dimensional tomographic information is called B scan. Further, three-dimensional tomographic information can be acquired by scanning the measurement light on the eye E to be inspected in a direction orthogonal to the scanning directions of both the A scan and the B scan. This scanning of the measurement light is called a C scan. In particular, when two-dimensional raster scanning is performed in the bottom surface of the eye E to be examined when acquiring three-dimensional tom information, the direction in which high-speed scanning is performed is the B-scan direction, and the direction in which scanning is performed at a relatively low speed is C. Called the scan direction. The B scan and the C scan are performed by the X scanner 402 and the Y scanner 403 described above.

Next, the reference optical system 50 in the SS-OCT apparatus 1 will be described with reference to FIG. FIG. 2 shows a schematic configuration of a reference optical system 50 of the SS-OCT apparatus 1 according to an embodiment of the present invention. The reference optical system 50 includes a strong lens 502, a second light amount adjusting means 51, a first mirror 503, a second mirror 504, a dispersion compensating glass 505, an optical path length adjusting means 52, a condensing unit 53, and a polarization controller 507. doing.

The reference light emitted from the interference unit 30 is guided to the reference optical system 50 by the optical fiber 500, and is emitted from the ferrule 501 to the reference optical system 50. The reference light emitted from the ferrule 501 reaches the second light amount adjusting means 51 after being made parallel light by the strong lens 502.

The second light amount adjusting means 51 includes a variable transmittance ND filter 510 (Neutral Density), a motor 511, a shaft 512, and a pressing member 513. The motor 511 is connected to the variable transmittance ND filter 510 via the shaft 512, and rotates the variable transmittance ND filter 510. The pressing member 513 fixes the variable transmittance ND filter 510 to the shaft 512. As shown by the dotted line in FIG. 2, the reference light incident on the variable transmittance ND filter 510 is refracted and transmitted toward the first mirror 503 and transmitted through the variable transmittance ND filter 510. On the other hand, the multiple reflected light generated by the variable transmittance ND filter 510 tries to be transmitted eccentrically from the reference light because the incident surface of the variable transmittance ND filter 510 is inclined with respect to the plane perpendicular to the optical axis. To do. However, since the transmission region of the multiple scattered light is shielded by the pressing member 513, these lights do not reach the first mirror 503. In the second light amount adjusting means 51, the motor 511 is driven according to the interference intensity of the interference light detected by the detection unit 60, and the reference light is transmitted by changing the transmission region of the reference light of the variable transmittance ND filter 510. Adjust the amount of light.

The configuration of the second light amount adjusting means 51 is not limited to the example described here, and may be configured by, for example, a shielding plate connected to the motor. Further, in the present embodiment, the first light amount adjusting means 202 described above has the same configuration as the second light amount adjusting means 51 described here. However, both light intensity adjusting means do not have to have the same configuration, and one of them may be configured to be a shielding plate.

In this embodiment, the path of the reference light in the reference optical system 50 is U-shaped by the first mirror 503 and the second mirror 504. With this arrangement, the optical path length can be efficiently obtained, and the device can be miniaturized. However, the path of the reference light is not limited to the configuration of this embodiment, and these optical members may be arranged in a straight line, or mirrors may be arranged so that the optical path is L-shaped or S-shaped. You may. Further, the dispersion compensating glass 505 arranged in the optical path of the reference light has a dispersion characteristic that makes the dispersion of the reference light correspond to the dispersion of the eye E to be examined, which is irradiated with the measurement light when the return light is obtained. Compensates for the degree of dispersion of the reference light.

The optical path length adjusting means 52 is provided with a prism-type retroreflector 520, and the retroreflector 520 can be moved in the direction of the arrow in FIG. 2 by a motor (not shown). By moving the retroreflector 520 in the direction of the arrow, the optical path length of the reference optical system 50 can be adjusted according to the optical path length of the measurement optical system 40 in which the measurement light passes through the eye E to be inspected. The incident surface of the retroreflector 520 is inclined by an angle θ with respect to the plane perpendicular to the optical axis as shown by the alternate long and short dash line. As a result, it is possible to prevent the specularly reflected light of the retroreflector 520 from becoming a return light that returns in the opposite direction in the same optical path, and it is possible to prevent the multiple reflected light from being combined.

The reference light folded back by the first mirror 503 and the second mirror 504 via the optical path length adjusting means 52 is collected by the condensing unit 53 and is imaged in a spot shape on the core of the ferrule 532. The reference light is guided to the optical fiber 508 connected to the ferrule 532 via the ferrule 532. After that, the reference light is polarized according to the measurement light by the polarization controller 507 provided in the optical fiber 508, and is incident on the interference unit 30 via the optical fiber 508.

Here, in an optical system in which the incident end and the emitted end of the optical fiber are different as in this embodiment, it is necessary to efficiently combine the light flux particularly at the incident end. Therefore, in this embodiment, this requirement is satisfied by using the strong lens 530 and the weak lens 531 in the condensing unit 53 and assembling the condensing unit 53 by the following procedure. The terms "weak lens" and "strong lens" used in the following description and the like represent the relative strength of lenses used in the same optical system. The absolute value of the focal length is larger for a weak lens than for a strong lens.

In the condensing unit 53 shown in FIG. 2, first, the strong lens 530 and the ferrule 532 are aligned in the XYZ3 direction. In the alignment, for example, the ferrule 532 is aligned with respect to the center of the optical axis of the strong lens 530 in the 2 (XY) direction of the plane perpendicular to the optical axis. After that, the ferrule 532 is aligned in the optical axis (Z) direction so that the focal length of the strong lens 530 is appropriate. At this time, the weak lens 531 is temporarily fixed between the strong lens 530 and the ferrule 532 so that the region near the optical axis center of the weak lens 531 does not overlap with the region near the optical axis center of the strong lens 530 and the ferrule 532. There is. After the alignment of the strong lens 530 and the ferrule 532 in the XYZ3 direction is completed, the strong lens 530 and the ferrule 532 are permanently attached to the holding member.

However, at that time, movement may occur in one or more optical components. Known permanent attachment methods of the optics include laser welding, UV or thermosetting adhesives, soldering, etc. In any of these methods, the optics move during the attachment process. It can occur. Therefore, by moving the temporarily fixed weak lens 531 in the XY direction after these permanent fixings, it is possible to compensate for the loss of coupling efficiency caused by the movement of the optical member described above. As a result, highly accurate alignment between the luminous flux and the ferrule 532 is realized. It should be noted that the weak lens 531 may move even when the weak lens 531 is permanently attached. However, since the weak lens 531 has a smaller lens power than the strong lens 530, the influence on the coupling efficiency can be ignored as compared with other optical members such as the strong lens 530 and the ferrule 532.

In such a configuration, it is desirable that the absolute value of the focal length of the strong lens 502 and the absolute value of the composite focal length of the strong lens 530 and the weak lens 531 match. When these two focal lengths match, the same member can be used for the ferrule 501 and the ferrule 532.

Further, the ferrule 532 is subjected to TEC processing to increase the core diameter, so that the allowable amount of deviation of the luminous flux with respect to the ferrule 532 in the XY direction can be increased. The TEC process described here refers to a process in which the core diameter of the fiber is substantially increased by heat treatment or the like. By increasing the core diameter of the ferrule 532 in this way, it is possible to suppress the influence of the displacement of the ferrule 532 due to the change in the environmental temperature in which the SS-OCT apparatus is used, and to maintain the coupling efficiency. Further, it is desirable to match the focal lengths of the optical members involved in the incident and emission of the reference light, and to perform TEC processing on the ferrule 501 from the same viewpoint as the ferrule 532. Further, since the ferrule 501 and the strong lens 502 and the ferrule 532, the weak lens 531 and the strong lens 530 are held by the same holding member, they are relative to the incident side and the exit side with respect to the change in the environmental temperature. The amount of misalignment can be reduced. The optical member included in the reference optical system 50 described above for adjusting the optical path length of the reference light constitutes the adjustment optical system.

Next, with reference to FIGS. 3 (a) and 3 (b), the flow path of the cooling gas (so-called outside air) in the SS-OCT apparatus according to the embodiment of the present invention is of the SS-OCT apparatus. The position of the light source included in the housing and the arrangement of each optical system will be described. FIG. 3A shows a side view of the SS-OCT apparatus, and FIG. 3B shows a rear view. The SS-OCT device includes a gantry 1001, a face cradle 1004, an optical unit 1104, a moving pedestal 1002, and an operating member 1003. Further, the optical unit 1104 is a reference optical unit 1102, a measurement optical unit 1103, a light source unit 1105, a duct 1107, and a fan 1106 fixed to the exterior cover, which are arranged in an exterior cover that defines the outer edge of the optical unit 1104. Has.

The gantry 1001 that holds the entire device mainly contains an electrical component of the device, such as a power supply (not shown). The face cradle 1004 that supports the face of the subject is fixed and supported on the gantry 1001. When aligning the subject with the optical unit 1104, the moving table 1002 for moving the optical unit 1104 including the exterior cover in the horizontal direction and the vertical direction is movably supported by the gantry 1001. That is, the optical unit 1104 is movable with respect to the eye E to be inspected in the three axial directions of XYZ, and these movements perform these alignments. Further, the operating member 1003 is supported by the gantry 1001 via the moving table 1002, and the operator gives an instruction such as movement of the moving table 1002 via the operating member 1003.

In this embodiment, the reference optical unit 1102 is configured as a box-shaped unit in which the reference optical system 50 shown in FIG. 1 and the like is built in a housing. Further, the measurement optical system 40 described above is built in the box body shown as the measurement optical unit 1103, and the light source unit 10 described above is built in the box body shown as the light source unit 1105, respectively. In addition, other configurations of the SS-OCT device 1 described above are also included in each unit as appropriate. Only the light source unit 10 is arranged in the light source unit 1105 as a high heat source, separated from other configurations. The light source unit 10, the measurement optical system 40, and the reference optical system 50 are each heat-separated from each other by being built in the housing.

In the following description, the direction in which the face cradle 1004 is arranged in the SS-OCT device 1 shown in FIG. 3A is the front side (front side), and the opposite direction is the rear side (rear side). Further, the left and right sides of the SS-OCT device 1 shown in FIG. 3 (b) with respect to the front side and the rear side are referred to as side surface sides (sideways). Further, the side on which the gantry 1001 is arranged with respect to the optical unit 1104 is referred to as a lower side (lower side), and the opposite side of the lower side of the optical unit 1104 is referred to as an upper side (upper side). It is also possible to understand that the direction in which the heated gas rises (upward in the vertical direction) is upward, and the opposite is downward.

Here, in the measurement optical system 40, the measurement light and the return light are guided between the optical elements mainly as spatial light. Therefore, the influence of the rise in the environmental temperature is considered to be limited, considering the optical member such as a lens. On the other hand, in the reference optical system 50, the influence of the environmental temperature on the arrangement of various optical members such as the incident accuracy of the reference light on the ferrule 532 described above must be taken into consideration. That is, it is necessary to consider the influence of the increase in the environmental temperature on the reference optical system 50 more than on the measurement optical system 40.

In this embodiment, in view of the above, the light source unit 1105 is arranged so as to be fixed to the ceiling portion on the upper side in the optical portion 1104 or close to the ceiling portion. Further, the reference optical unit 1102 is arranged at a lower position in the optical unit 1104 so as to be separated from the light source unit 1105. The measurement optical unit 1103 is joined to the reference optical unit 1102, and is arranged in the optical unit 1104 near the inner surface of the front side wall close to the face cradle 1004. Further, the measurement optical unit 1103 and the light source unit 1105 are separated from each other and are thermally isolated.

In this embodiment, the box body constituting the light source unit 1105 is provided with a cooling gas inflow port 1105a on the lower surface and a cooling gas outlet 1105b on the side surface side on the side where the fan 1106 is arranged. .. A duct 1107 that constitutes an exhaust path for cooling gas is arranged between the outlet 1105b and the fan 1106. The duct 1107 communicates these so that the exhaust capacity of the fan 1106 acts substantially directly on the outlet 1105b of the light source unit 1105. The gas flowing out from the outlet 1105b of the light source unit 1105 into the light source unit is heated by the wavelength sweep light source 100. However, the presence of the duct 1107 can prevent the heated gas from diffusing into the space where the optical unit 1104 such as the reference optical unit 1102 and the measurement optical unit 1103 other than the light source unit 1105 is arranged. In this embodiment, the opening of the outlet 1105b and the opening of the connecting portion of the duct 1107 have the same size, but the opening of the connecting portion of the duct 1107 may be larger as long as the diffusion of the heated gas can be prevented. Similarly, regarding the exhaust opening of the fan 1106 and the connection opening of the duct 1107, the connection opening of the duct 1107 may be larger as long as the diffusion of the heated gas can be prevented.

Next, the flow of the cooling gas formed inside the optical unit 1104 having the above configuration will be described. The optical unit 1104 moves in the vertical direction, but the moving table 1002 supporting the optical unit 1104 does not move up and down. In order to enable this operation, there is a gap on the entire circumference between the lower surface of the exterior cover of the optical unit 1104 and the moving table 1002. By using the gap as a vent, the outside air of the optical portion 1104 can flow into the inside of the optical portion 1104 through the vent along the arrow indicated by FL1 in the drawing. In addition, as the vent, a gap originally existing in the structure may be provided as it is. Further, the ventilation holes may be not only in the form of gaps but also in a plurality of holes, slits and the like arranged in an annular shape on the entire circumference of the lower surface of the exterior cover. Further, the vent may be arranged on the entire lower circumference of the peripheral surface of the exterior cover. However, in view of the exhaust capacity of the fan 1106, the area of the open portion of the vent is determined or changed so that the outside air passing through the light source unit 1105 can effectively cool the inside at an appropriate flow rate and flow rate. It is preferable to do so.

The reference optical unit 1102 and the measurement optical unit 1103 are arranged so as to provide an even gap from the inner walls of both side surfaces of the optical unit 1104. That is, both optical units are arranged substantially in the center of the optical unit 1104 so that both side surfaces of the reference optical unit 1102 and the measurement optical unit 1103 are at equal distances from the inner surface of the side wall of the optical unit 1104. To. The outside air that has flowed into the optical unit 1104 along FL1 then flows along the arrow indicated by FL2 that passes through these gaps. More specifically, it contacts both side surfaces of the reference optical unit 1102 and the measurement optical unit 1103 and flows around these configurations toward the light source unit 1105 while cooling them. As described above, since the gaps existing on the side surfaces of both optical units have the same distance, the flow rate and the flow velocity of the outside air flowing through the gaps are substantially equal. The outside air that reaches the light source unit 1105 while uniformly cooling the reference optical unit 1102 and the like from both side surfaces flows into the light source unit 1105 through the above-mentioned inflow port.

The outside air that has reached the inside of the light source unit 1105 is drawn to the outlet side by the exhaust action of the fan 1106 and flows out into the duct 1107. At that time, the outside air cools the wavelength sweep light source 100 in the light source unit 1105 and is heated by the wavelength sweep light source 100. The heated outside air flowing out into the duct 1107 is discharged to the outside of the optical unit 1104 by the fan 1106. The arrow indicated by FL3 in the figure indicates the flow of gas that flows into the light source unit 1105, is sucked into the duct 1107, is drawn by the fan 1106, and is discharged to the outside of the optical unit 1104. Further, the exhaust capacity of the fan 1106 generates a forced gas flow FL1, a gas flow FL2, and a gas flow FL3.

According to this embodiment, the reference optical unit 1102 and the measurement optical unit 1103 are cooled by the gas flow FL2 to suppress the temperature rise of these, and the temperature rise in at least the lower space in the optical unit 1104 is also suppressed. In particular, by arranging vents all around the lower surface of the optical unit 1104, the temperature distribution in the lower space can be made uniform, and almost all of the gas in the optical unit 1104 is effectively replaced by the outside air. You can also do it. At the same time, it is possible to suppress the generation of a so-called stagnation region of the air flow in the optical unit 1104. Further, by arranging the light source unit 1105 near the ceiling side of the optical unit 1104, diffusion of the peripheral gas heated by the light source unit 1105 due to gas circulation in the optical unit 1104 is suppressed. By adding the effect of the gas flow FL2 to this, the diffusion of the peripheral gas heated by the light source unit 1105 into the optical unit 1104 is further suppressed. Further, since the gas heated in the light source unit 1105 is forcibly discharged to the outside of the optical unit 1104 by the fan 1106, the influence of the heated gas in the light source unit 1105 on the optical unit 1104 can be suppressed.

As described above, the image pickup apparatus according to one aspect of the present invention includes an optical unit 1104 which is a third housing, a light source unit 1105 built in the optical unit 1104, a measurement optical system 40, and a reference optical system 50. It has an optical system comprising, a fan 1106, and a duct 1107. The optical unit 1104 has a vent below which allows outside air to flow in. The light source unit 1105 is arranged above the optical unit 1104, and has a wavelength sweep light source 100 that emits light that generates measurement light for obtaining information on the eye E to be inspected, and a gas in the optical unit 1104 that incorporates the light source. Has a light source housing having an inflow port capable of flowing into the interior. The light source housing constitutes the first housing in this embodiment.

The above-mentioned optical system is arranged in the optical unit 1104, and guides the measurement light to the eye E to be inspected, and the detector 600 as a detection means for detecting information for acquiring an image of the eye E to be inspected has the measurement light E. It has at least an optical member that guides the return light from. In the above-described embodiment, the case where the optical member constituting the reference optical system 50 is built in the reference optical unit 1102 as the housing for the optical member is illustrated. The housing for the optical member constitutes the second housing in this embodiment. However, the configuration built in the housing for the optical member and thermally isolated from the light source unit 1105 is not limited to the optical member of the reference optical system 50, and may be a member or an optical member that is affected by changes in the environmental temperature. Therefore, the housing for the optical member is defined as a configuration in which the housing for the optical member is arranged below the inside of the optical unit 1104 and above the vent, and incorporates a part of the optical member of the optical system. Further, in this case, the housing constituting the measurement optical unit 1103 constitutes a fourth housing which is a second optical member housing containing an optical member which is not built in the optical member housing. It becomes. Note that some optical members include an optical system that adjusts the optical path length of the reference light, an optical fiber that guides the reference light to the reference optical unit 1102, and the like. These members are affected by heat, which is collectively called the environmental temperature, and change their optical characteristics, and the effect may appear in the generated tomographic image.

The fan 1106 forcibly exhausts gas inside the optical unit 1104, that is, inside the housing through an exhaust opening provided above the housing for the optical member on the wall of the optical unit 1104. Further, the duct 1107 communicates the inside of the light source unit 1105 with the exhaust opening so that the gas in the light source unit 1105 can be discharged to the outside of the optical unit 1104 by the fan 1106. That is, the fan 1106 enters the optical unit 1104 from the vent on the lower surface of the optical unit 1104, and generates an air flow reaching the inside of the light source unit 1105 via the inflow port 1105a on the lower surface of the light source unit 1105. Further, the fan 1106 generates an air flow from the outlet 1105b of the light source unit 1105 to the outside of the optical unit 1104 via the duct 1107.

With the above configuration, even when the reference optical system and the light source serving as a high heat source are arranged in the same housing, the temperature rise of the reference optical system and each configuration in the housing can be reduced. Is possible. Therefore, even when the SS-OCT device using the wavelength sweep light source is miniaturized, the heat from the wavelength sweep light source for the reference optical system or the like can be obtained by imparting the above-mentioned structure to the SS-OCT device. It is possible to reduce the influence of the image and maintain the performance of generating an image. Further, in the above-described configuration, even if the light source unit 1105 is arranged in the vicinity of the reference optical unit 1102 in the device due to the miniaturization of the device, the temperature rise in the reference optical unit 1102 due to the presence of the determined gas flow. Can be reduced.

In this embodiment, a gap structurally arranged under the optical unit 1104 is utilized, and the outside air sucked from the external space through the gap is flowed so as to come into contact with the reference optical unit 1102. The cooling effect of 1102 is obtained. Further, the outside air after cooling the reference optical unit 1102 is sucked into the light source unit 1105 accommodating the light source, and the outside air after cooling the light source is discharged to the outside through the duct 1107 and the fan 1106 without being diffused into the optical unit 1104. It is discharging. According to the above configuration, the gap between the optical unit 1104 and the moving table 1002 originally possessed by the conventional OCT device is utilized as a suction port, and the inside of the optical unit 1104 is effectively provided only by adding the duct 1107 and the fan 1106. Can be cooled.

However, the configuration for sucking or discharging the outside air of the imaging device according to the present invention is not limited to the above-described embodiment. As the suction port, for example, a further ventilation port may be provided in a region facing the light source unit 1105 on the inner surface of the side wall of the exterior cover of the optical unit 1104. It is necessary to perform additional processing to the conventional configuration by providing the vent, but when paying attention to the cooling effect of the light source unit 1105, a larger volume of outside air is blown to the light source unit 1105 to the wavelength sweep light source 100. It can be expected to enhance the cooling effect of. In this case, the additional vent can be defined as a second vent provided on the side wall or front and rear walls of the optical unit 1104 to allow outside air to flow into the optical unit 1104. Further, in this case, a further inflow port capable of introducing outside air may be provided on the surface of the light source unit 1105 facing the suction port.

Further, although the fan 1106 is fixed to the exterior cover of the optical unit 1104 in this embodiment, the duct 1107 may be further extended and the fan 1106 may be arranged ahead of the duct 1107. Further, from the viewpoint of miniaturization of the OCT device, there is a possibility that the device becomes large in size, but it is also possible to arrange the fan 1106 in the portion communicating with the duct 1107 of the light source unit 1105. Further, the outlet of the optical unit 1104 in which the fan 1106 is arranged in this embodiment is arranged above the reference optical unit 1102 so that the gas heated by the light source unit 1105 does not approach the reference optical unit 1102. Is preferable. Here, when the OCT device is miniaturized and slimmed down, particularly when the upper part is slimmed down, it is assumed that it may be difficult to secure the mounting position of the fan 1106. By arranging the duct 1107, the degree of freedom in the mounting position of the fan 1106 is increased, and even when the fan 1106 is arranged as downward as possible, the gas heated by the light source unit 1105 is attached to the reference optical unit 1102. Diffusion can be suppressed.

(Other Examples)
The present invention targets an SS-OCT apparatus using a wavelength sweeping light source that becomes hot, and the SS-OCT apparatus is also described in this embodiment. However, the application target of the present invention is not limited to the SS-OCT apparatus, and various OCT apparatus, such as a scanning laser ophthalmoscope (SLO apparatus), which uses a high temperature light source and is easily affected by the environmental temperature. An imaging device incorporating the optical member of the above is also included.

Further, the present invention is not limited to the above-described embodiment, and various modifications and modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the case where the object to be inspected is an eye is described, but it is also possible to apply the present invention to an object to be inspected such as skin or an organ other than the eye. In this case, the present invention has an aspect as a medical device other than an ophthalmic device, for example, an endoscope. Therefore, it is desirable that the present invention is grasped as an imaging device exemplified by an ophthalmic apparatus, and the eye to be inspected is grasped as one aspect of an object to be inspected.

1: SS-OCT device (imaging device), 10: light source unit, 20: light amount adjustment optical system, 30: interference unit, 40: measurement optical system, 50: reference optical system, 60: detection unit, 70: information acquisition unit , 80: Display unit, E: Eye to be inspected, 51: Light amount adjusting means, 52: Light path length adjusting means, 53: Condensing unit, 530: Strong lens, 531: Weak lens, 532: Ferrule, 1102: Reference optical unit ( Optical member housing), 1103: Measuring optical unit (optical member housing), 1105: Light source unit, 1106: Fan, 1107: Duct

Claims (17)

The subject is based on the interference light obtained by combining the return light obtained by irradiating the object to be inspected with the measurement light separated from the light emitted from the light source and the reference light separated from the light. An imaging device that acquires an image of an inspection object.
A first housing containing the light source and having a gas inlet and outlet,
A second housing containing at least a part of the reference light optical system and
A third housing containing the first housing and the second housing and having a vent for gas to flow in and an exhaust opening for gas to flow out.
A duct that communicates the outlet and the exhaust opening,
The gas flows into the inside of the third housing from the ventilation port, flows into the inside of the first housing from the inflow port through the periphery of the second housing, and flows into the inside of the first housing from the inflow port. An image pickup apparatus comprising: a fan for forming a gas flow so as to be discharged from the inside of a body through the outlet and the exhaust opening. The imaging device according to claim 1, wherein the vent is configured as an annular vent on the entire circumference of the lower surface of the third housing. Said first housing, an imaging apparatus according to claim 1 or 2, characterized in that it is disposed above the third enclosure. The imaging device according to any one of claims 1 to 3, wherein the second housing is arranged below the third housing and above the vent. The exhaust opening, the second housing imaging apparatus according to any one of claims 1 to 4, characterized in the provided et the possible upper. The third housing has the vent below.
It said first housing is positioned above the third enclosure,
The second housing is disposed above the third casing of the lower and the vent,
The exhaust opening is pre Symbol second housing imaging apparatus according to any one of claims 1 to 5, characterized in that provided on the side wall of the definitive over the third housing than. The imaging device according to any one of claims 1 to 6, wherein the third housing is movable in three axial directions with respect to the object to be inspected. A moving base supported by a pedestal is further provided so that the third housing can move in the three axial directions.
The imaging device according to claim 7, wherein the vent is formed by a gap between the moving table and the third housing. Further equipped with a fourth housing containing an optical system for measurement light,
Said fourth housing is positioned close country in the second housing wherein the first housing from body,
The fan causes the gas so that the gas that has flowed into the inside of the third housing from the ventilation port flows into the inside of the first housing from the inflow port through the periphery of the fourth housing. The imaging apparatus according to any one of claims 1 to 8, wherein the imaging apparatus is configured to form a flow of the above . The imaging device according to claim 9, wherein the fourth housing includes an optical member that is not built in the second housing. The imaging apparatus according to claim 9 or 10 , wherein both side surfaces of the second housing and the fourth housing are located at equal distances from the inner surface of the side wall of the third housing. .. The imaging device according to any one of claims 1 to 11, wherein the third housing is provided on a side wall or a front and rear wall and has a second vent through which the gas can flow. The subject is based on the interference light obtained by combining the return light obtained by irradiating the object to be inspected with the measurement light separated from the light emitted from the light source and the reference light separated from the light. An imaging device that acquires an image of an inspection object.
A light source unit provided with the light source and
A reference optical unit provided with at least a part of the reference light optical system and
A moving table supported by a gantry so that the light source unit and the reference optical unit provided in an exterior cover having an exhaust opening through which gas flows can be moved.
A duct that communicates the inside of the light source unit with the exhaust opening,
The gas that has flowed into the exterior cover through the gap between the exterior cover and the moving table flows into the inside of the light source unit via the periphery of the reference optical unit, and the inflowing gas passes through the duct. An imaging device comprising: a fan for forming a gas flow so as to be exhausted from the exhaust opening. The imaging apparatus according to any one of claims 1 to 13, wherein at least a part of the optical system of the reference light includes an optical member for adjusting the optical path length of the reference light. The imaging according to any one of claims 1 to 14, wherein at least a part of the optical system of the reference light includes an optical member that collects the reference light that has passed through the optical system of the reference light. apparatus. At least a part of the optical system of the reference light is characterized by including an optical fiber for guiding the reference light in a wave combining means for combining the reference light separated from the light emitted from the light source and the measurement light. The imaging device according to any one of claims 1 to 15. The object to be inspected, an imaging apparatus according to any one of claims 1 to 16 characterized in that it is a subject's eye.

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