Ophthalmic device, control method thereof, and program

Abstract

To provide a technology to acquire an image of high quality of an eye to be examined by a simple configuration.SOLUTION: An ophthalmologic device includes a light source, an illumination optical system, an optical scanner, an imaging optical system, and a control unit. The illumination optical system generates a slit-like illumination light by using a light from the light source. The optical scanner deflects the illumination light and guides it to the ocular fundus of the eye to be examined. The imaging optical system guides a return light of the illumination light from the ocular fundus to an image sensor that captures a light reception result in a region of a light reception surface corresponding to an illumination region of the illumination light in the ocular fundus moved by the optical scanner by a rolling shutter method. The control unit controls a deflection angle of the illumination light by the optical scanner. The optical scanner outputs a scanner position signal corresponding to the deflection angle of the illumination light. The image sensor starts capturing of the light reception result on the return light in synchronization with the scanner position signal.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an ophthalmic apparatus, a control method thereof, and a program. [Background technology]

[0002] In recent years, screening tests using ophthalmic devices have become common. Since such ophthalmic devices are expected to be used for self-examination, there is a demand for them to be made smaller and lighter.

[0003] For example, Patent Documents 1 and 2 disclose an ophthalmic apparatus configured to illuminate a subject's eye in a pattern using slit light and detect the return light with a CMOS (Complementary Metal Oxide Semiconductor) image sensor. This ophthalmic apparatus can obtain an image of the subject's eye with a simple configuration by adjusting the illumination pattern and the timing of light reception by the CMOS image sensor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 7,831,106 [Patent Document 2] U.S. Patent No. 8,237,835 Summary of the Invention [Problem to be solved by the invention]

[0005] In this type of ophthalmic device, the CMOS image sensor receives and captures the returning light of the illumination light at the appropriate timing, thereby eliminating the effects of unnecessary scattered light and improving the image quality of the image of the test eye obtained.

[0006] However, in the conventional method, it is not possible to synchronize the control on the illumination side with the control on the light receiving side with high accuracy. As a result, it is necessary to receive and capture the return light while taking into account the time lag between the control on the illumination side and the control on the light receiving side, which results in receiving unnecessary scattered light. As a result, there is a problem that the quality of the image of the subject's eye obtained is degraded.

[0007] The present invention has been made in consideration of the above circumstances, and one of its objectives is to provide a new technique for acquiring a high-quality image of a subject's eye with a simple configuration. [Means for solving the problem]

[0008] A first aspect of some embodiments includes an illumination optical system including a light source and a slit configured to be movable in an optical axis direction according to a state of a subject's eye, and generating slit-shaped illumination light by irradiating light from the light source onto the slit; an optical scanner that deflects the illumination light and guides it to a fundus of the subject's eye; an imaging optical system that guides return light of the illumination light from the fundus to an image sensor that captures, by a rolling shutter method, a light reception result of an area of ​​a light receiving surface corresponding to an illumination area of ​​the illumination light on the fundus moved by the optical scanner; and a control unit that controls a deflection angle of the illumination light by the optical scanner. and at least one of a relative position and a relative orientation of the light source with respect to the slit can be changed with the movement of the slit; The optical scanner outputs a scanner position signal corresponding to a deflection angle of the illumination light, and the image sensor starts acquiring a result of receiving the return light in synchronization with the scanner position signal.

[0009] A second aspect of some embodiments, in the first aspect, includes a first voltage detection circuit that changes a trigger signal depending on a comparison result between the scanner position signal and a first threshold voltage, and the image sensor starts capturing the light receiving result in synchronization with the change in the trigger signal.

[0010] In a third aspect of some embodiments, in the first or second aspect, the control unit outputs a scanner control signal to the optical scanner and deflects the illumination light at a deflection angle corresponding to the scanner control signal.

[0011] In a fourth aspect of some embodiments, in any one of the first to third aspects, the light source is switched from an on state to an off state or from an off state to an on state in synchronization with the scanner position signal.

[0012] A fifth aspect of some embodiments is the fourth aspect, further comprising a second voltage detection circuit that changes a light source control signal for controlling the light source on and off depending on a comparison result between the scanner position signal and a second threshold voltage, and the light source is switched from an on state to an off state or from an off state to an on state in synchronization with the change in the light source control signal.

[0013] In a sixth aspect of some embodiments, in the fifth aspect, the image sensor starts capturing the light receiving result and ends capturing the light receiving result during a period in which the light source is in an on state.

[0014] In a seventh aspect of some embodiments, in any one of the first to sixth aspects, the image sensor is a CMOS image sensor.

[0015] An eighth aspect of some embodiments includes an illumination optical system including a light source and a slit configured to be movable in an optical axis direction according to a state of a subject's eye, and generating slit-shaped illumination light by irradiating light from the light source onto the slit; an optical scanner that deflects the illumination light and guides it to a fundus of the subject's eye; an imaging optical system that guides return light of the illumination light from the fundus to an image sensor that captures, by a rolling shutter method, a light reception result of an area of ​​a light receiving surface corresponding to an illumination area of ​​the illumination light on the fundus moved by the optical scanner; and a control unit that controls a deflection angle of the illumination light by the optical scanner. and a lens that can change at least one of a relative position and a relative orientation of the light source with respect to the slit in accordance with the movement of the slit. The control method for an ophthalmic apparatus includes a first output step in which the optical scanner outputs a scanner position signal corresponding to a deflection angle of the illumination light, and a light reception result acquisition step in which the image sensor starts to acquire a light reception result of the return light in synchronization with the scanner position signal.

[0016] A ninth aspect of some embodiments is the eighth aspect, which includes a first voltage detection step of changing a trigger signal depending on a comparison result between the scanner position signal and a first threshold voltage, and the light reception result acquisition step includes the image sensor starting to capture the light reception result in synchronization with the change in the trigger signal.

[0017] A tenth aspect of some embodiments, in the eighth or ninth aspect, includes a second output step in which the control unit outputs a scanner control signal to the optical scanner, and the optical scanner deflects the illumination light at a deflection angle corresponding to the scanner control signal.

[0018] An eleventh aspect of some embodiments is based on any one of the eighth to tenth aspects and further includes a light source control step of switching the light source from an on state to an off state or from an off state to an on state in synchronization with the scanner position signal.

[0019] A twelfth aspect of some embodiments, in the eleventh aspect, includes a second voltage detection step of changing a light source control signal for controlling the light source on and off depending on a comparison result between the scanner position signal and a second threshold voltage, and the light source control step switches the light source from an on state to an off state or from an off state to an on state in synchronization with the change in the light source control signal.

[0020] In a thirteenth aspect of some embodiments, in the twelfth aspect, the light receiving result acquisition step is such that the image sensor starts acquiring the light receiving result and ends acquiring the light receiving result while the light source is in an on state.

[0021] In a fourteenth aspect of some embodiments, in any one of the eighth to thirteenth aspects, the image sensor is a CMOS image sensor.

[0022] A fifteenth aspect of some embodiments is a program for causing a computer to execute each step of the control method for an ophthalmic apparatus according to any one of the eighth to fourteenth aspects.

[0023] The configurations according to the above-described multiple aspects can be combined in any desired manner. Effect of the Invention

[0024] According to the present invention, it is possible to provide a new technique for acquiring a high-quality image of a subject's eye with a simple configuration. [Brief description of the drawings]

[0025] [Figure 1] 1 is a schematic diagram illustrating an example of the configuration of an optical system of an ophthalmic apparatus according to a first embodiment. [Diagram 2] 2 is a schematic diagram showing an example of the configuration of a control system of the ophthalmic apparatus according to the first embodiment. FIG. [Diagram 3] 1 is a schematic diagram illustrating an example of the configuration of an optical system of an ophthalmic apparatus according to a first embodiment. [Figure 4] 3A to 3C are diagrams illustrating the operation of the ophthalmologic apparatus according to the first embodiment. [Diagram 5] 3A to 3C are diagrams illustrating the operation of the ophthalmologic apparatus according to the first embodiment. [Figure 6] 3A to 3C are diagrams illustrating the operation of the ophthalmologic apparatus according to the first embodiment. [Figure 7] 3A to 3C are diagrams illustrating the operation of the ophthalmologic apparatus according to the first embodiment. [Figure 8] 4 is a sequence diagram showing an example of the operation of the ophthalmologic apparatus according to the first embodiment. FIG. [Figure 9] 3A to 3C are diagrams illustrating the operation of the ophthalmologic apparatus according to the first embodiment. [Figure 10] 13 is a schematic diagram showing an example of the configuration of a control system of an ophthalmic apparatus according to a second embodiment. FIG. [Figure 11] 11A to 11C are diagrams illustrating the operation of the ophthalmologic apparatus according to the second embodiment. [Figure 12] FIG. 11 is a sequence diagram showing an example of the operation of the ophthalmologic apparatus according to the second embodiment. [Figure 13]11A to 11C are diagrams illustrating the operation of the ophthalmologic apparatus according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] An example of an embodiment of an ophthalmic apparatus, a control method thereof, and a program according to the present invention will be described in detail with reference to the drawings. Note that the contents of the documents described in this specification can be appropriately used as the contents of the following embodiment.

[0027] The ophthalmic apparatus according to the embodiment illuminates a predetermined portion of the subject's eye while moving the irradiation position (illumination area, irradiation range) of a slit-shaped illumination light, and receives return light from the predetermined portion using an image sensor in which light receiving elements are arranged one-dimensionally or two-dimensionally. The result of receiving the return light is read out from the light receiving elements at the light receiving position of the return light corresponding to the irradiation position of the illumination light, in synchronization with the timing of moving the irradiation position of the illumination light. In some embodiments, the predetermined portion is the anterior segment or the posterior segment. The anterior segment includes the cornea, iris, crystalline lens, ciliary body, Zinn's zonule, etc. The posterior segment includes the vitreous body, fundus, or the vicinity thereof (retina, choroid, sclera, etc.).

[0028] The control method of the ophthalmic apparatus according to the embodiment includes one or more steps for implementing processing executed by a processor (computer) in the ophthalmic apparatus according to the embodiment. The program according to the embodiment causes the processor to execute each step of the control method of the ophthalmic apparatus according to the embodiment.

[0029] In this specification, the term "processor" refers to a circuit such as a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), a field programmable gate array (FPGA)), etc. The processor realizes the functions according to the embodiment by, for example, reading and executing a program stored in a memory circuit or a storage device.

[0030] Hereinafter, a case will be described where the ophthalmic apparatus according to the embodiment mainly acquires an image of the fundus of the subject's eye. In the ophthalmic apparatus according to the first embodiment, the optical scanner and the light receiving element (image pickup element) are synchronized with high precision to improve the quality of the acquired image. In the ophthalmic apparatus according to the second embodiment, the optical scanner, the light receiving element, and the light source are synchronized with high precision to improve the quality of the acquired image.

[0031] First Embodiment [Optical system configuration] 1 to 3 show schematic diagrams of an example of the configuration of an ophthalmic apparatus according to the first embodiment. FIG. 1 shows an example of the configuration of an optical system of the ophthalmic apparatus 1 according to the first embodiment. FIG. 2 shows a block diagram of an example of the configuration of a control system (processing system) of the ophthalmic apparatus 1 according to the first embodiment. FIG. 3 shows a schematic diagram of an example of the configuration of the iris diaphragm 21 of FIG. 1 as viewed from the direction of the optical axis O. In FIGS. 1 to 3, similar parts are given the same reference symbols and descriptions will be omitted as appropriate.

[0032] The ophthalmic apparatus 1 includes a light source 10, an illumination optical system 20, an optical scanner 30, a projection optical system 35, a photographing optical system 40, and an imaging device 50. In some embodiments, the illumination optical system 20 includes at least one of the light source 10, the optical scanner 30, and the projection optical system 35. In some embodiments, the photographing optical system 40 includes the imaging device 50. In some embodiments, the projection optical system 35 or the photographing optical system 40 includes the optical scanner 30.

[0033] (light source 10) The light source 10 includes a visible light source that generates light in the visible region. For example, the light source 10 generates light having a central wavelength in a wavelength range of 420 nm to 700 nm. Such light source 10 includes, for example, an LED (Light Emitting Diode), an LD (Laser Diode), a halogen lamp, or a xenon lamp. In some embodiments, the light source 10 includes a white light source or a light source capable of outputting light of each color component of RGB. In some embodiments, the light source 10 includes a light source capable of switching between outputting light in the infrared region or light in the visible region. The light source 10 is disposed at a position optically non-conjugate with each of the fundus Ef and the iris.

[0034] (Illumination optical system 20) The illumination optical system 20 generates a slit-shaped illumination light using the light from the light source 10. The illumination optical system 20 guides the generated illumination light to the optical scanner 30.

[0035] The illumination optical system 20 includes an iris diaphragm 21, a slit 22, and a relay lens 23. Light from the light source 10 passes through an opening formed in the iris diaphragm 21, passes through an opening formed in the slit 22, and is transmitted through the relay lens 23. The relay lens 23 includes one or more lenses. The light transmitted through the relay lens 23 is guided to the optical scanner 30.

[0036] (Iris Diaphragm 21) The iris diaphragm 21 (specifically, an opening portion described later) can be arranged at a position that is optically approximately conjugate with the iris (pupil) of the subject's eye E. The iris diaphragm 21 has one or more opening portions formed at a position away from the optical axis O. For example, as shown in FIG. 3, the iris diaphragm 21 has opening portions 21A and 21B having a predetermined thickness formed along a circumferential direction centered on the optical axis O. The opening portions formed in the iris diaphragm 21 define the incident position (incident shape) of the illumination light on the iris of the subject's eye E. For example, by forming the opening portions 21A and 21B as shown in FIG. 3, when the pupil center of the subject's eye E is positioned on the optical axis O, it is possible to cause the illumination light to enter the eye from a position eccentric from the pupil center (specifically, a position point-symmetrical with respect to the pupil center).

[0037] In addition, by changing the relative position between the light source 10 and the opening formed in the iris diaphragm 21, it is possible to change the light amount distribution of the light passing through the opening formed in the iris diaphragm 21.

[0038] (Slit 22) The slit 22 (specifically, an opening described later) can be arranged at a position that is approximately optically conjugate with the fundus Ef of the subject's eye E. For example, the slit 22 has an opening formed in a direction corresponding to a line direction (row direction) read out from an image sensor 51 described later by a rolling shutter method. The opening formed in the slit 22 defines the irradiation pattern of the illumination light on the fundus Ef of the subject's eye E.

[0039] The slit 22 can be moved in the optical axis direction of the illumination optical system 20 by a moving mechanism (moving mechanism 22D described below). The moving mechanism moves the slit 22 in the optical axis direction under the control of a control unit 100 described below. For example, the control unit 100 controls the moving mechanism depending on the state of the subject's eye E. This makes it possible to move the position of the slit 22 depending on the state of the subject's eye E (specifically, the refractive power and the shape of the fundus Ef).

[0040] In some embodiments, the slit 22 is configured to be able to change at least one of the position and the shape of the opening without being moved in the optical axis direction according to the state of the subject's eye E. Such a function of the slit 22 is realized by, for example, a liquid crystal shutter.

[0041] The light from the light source 10 passes through an opening formed in the iris diaphragm 21 and is output as slit-shaped illumination light by passing through an opening formed in the slit 22. The slit-shaped illumination light passes through a relay lens 23 and is guided to the optical scanner 30.

[0042] (Optical Scanner 30) The optical scanner 30 is disposed at a position that is approximately optically conjugate with the iris of the subject's eye E. The optical scanner 30 deflects slit-shaped illumination light (slit-shaped light that has passed through an opening formed in the slit 22) that passes through the relay lens 23. Specifically, the optical scanner 30 deflects the slit-shaped illumination light for sequentially illuminating a predetermined illumination range of the fundus Ef while changing the deflection angle within a predetermined deflection angle range with the iris of the subject's eye E or its vicinity as the scanning center position, and guides the slit-shaped illumination light to the projection optical system 35. The optical scanner 30 is capable of deflecting the illumination light one-dimensionally or two-dimensionally.

[0043] In the case of one-dimensional deflection, the optical scanner 30 includes a galvanometer scanner that deflects the illumination light in a predetermined deflection angle range based on a predetermined deflection direction. In the case of two-dimensional deflection, the optical scanner 30 includes a first galvanometer scanner and a second galvanometer scanner. The first galvanometer scanner deflects the illumination light so as to move the irradiation position of the illumination light in a horizontal direction perpendicular to the optical axis of the illumination optical system 20. The second galvanometer scanner deflects the illumination light deflected by the first galvanometer scanner so as to move the irradiation position of the illumination light in a vertical direction perpendicular to the optical axis of the illumination optical system 20. Examples of the scanning mode for moving the irradiation position of the illumination light by the optical scanner 30 include horizontal scanning, vertical scanning, cross scanning, radial scanning, circular scanning, concentric circular scanning, and spiral scanning.

[0044] The optical scanner 30 is, for example, a non-resonant optical scanner. In this case, the control unit 100 described later can set one or more orientations of the deflection surface of the optical scanner 30 so that the illumination light is irradiated to a desired irradiation range. The optical scanner 30 can change the deflection angle of the illumination light (deflection angle of the deflection surface) by changing the orientation of the deflection surface under the control of the control unit 100 described later, and output a scanner position signal Spos at a voltage level corresponding to the deflection angle.

[0045] In some embodiments, the optical scanner 30 is, for example, a resonant optical scanner. In this case, the control unit 100 described later can set the direction of the deflection surface at the scan center and the scan range based on the scan center for the optical scanner 30 so that the illumination light is irradiated to a desired irradiation range. The optical scanner 30 can change the deflection angle of the illumination light (deflection angle of the deflection surface) by changing the direction of the deflection surface under the control of the control unit 100 described later, and output a scanner position signal Spos at a voltage level corresponding to the deflection angle.

[0046] (Projection optical system 35) The projection optical system 35 guides the illumination light deflected by the optical scanner 30 to the fundus Ef of the subject's eye E. In the embodiment, the projection optical system 35 guides the illumination light deflected by the optical scanner 30 to the fundus Ef via an optical path coupled to the optical path of the imaging optical system 40 by a hole mirror 45 serving as an optical path coupling member described later.

[0047] The projection optical system 35 includes a relay lens 41, a black dot plate 42, a reflecting mirror 43, and a relay lens 44. Each of the relay lenses 41, 44 includes one or more lenses.

[0048] (black dot plate 42) The black dot plate 42 is disposed at a position that is approximately optically conjugate with the lens surface of the objective lens 46 or its vicinity. This makes it possible to prevent the reflected light from the lens surface of the objective lens 46 from being guided to the light source 10 (illumination optical system 20).

[0049] In such a projection optical system 35 , the illumination light deflected by the optical scanner 30 passes through the relay lens 41 , passes through the black dot plate 42 , and is reflected by the reflecting mirror 43 toward the hole mirror 45 .

[0050] (Photographic optical system 40) The photographing optical system 40 guides the illumination light guided through the projection optical system 35 to the fundus Ef of the subject's eye E, and also guides the return light of the illumination light from the fundus Ef to the imaging device 50.

[0051] In the photographing optical system 40, the optical path of the illumination light from the projection optical system 35 and the optical path of the return light of the illumination light from the fundus Ef are combined. By using a hole mirror 45 as an optical path combining member that combines these optical paths, it is possible to perform pupil division of the illumination light and its return light.

[0052] The photographing optical system 40 includes a hole mirror 45, an objective lens 46, a focusing lens 47, a relay lens 48, and an imaging lens 49. Each of the relay lenses 48 includes one or more lenses.

[0053] (hole mirror 45) The hole mirror 45 has a hole formed therein, which is located on the optical axis of the photographing optical system 40. The hole of the hole mirror 45 is located at a position that is optically conjugate with the iris of the subject's eye E. The hole mirror 45 reflects the illumination light from the projection optical system 35 toward the objective lens 46 in the peripheral area of ​​the hole.

[0054] (Focusing lens 47) The focusing lens 47 can be moved in the optical axis direction of the photographing optical system 40 by a moving mechanism (not shown). The moving mechanism moves the focusing lens 47 in the optical axis direction under the control of a control unit 100 (described later). This allows the return light of the illumination light that has passed through the hole of the hole mirror 45 to be imaged on the light receiving surface of the image sensor 51 of the imaging device 50 according to the state of the subject's eye E.

[0055] In such an imaging optical system 40, the illumination light from the projection optical system 35 is reflected toward the objective lens 46 at the peripheral region of the hole formed in the hole mirror 45. The illumination light reflected at the peripheral region of the hole mirror 45 is refracted by the objective lens 46, enters the eye through the pupil of the subject's eye E, and illuminates the fundus Ef of the subject's eye E.

[0056] The return light of the illumination light from the fundus Ef is refracted by the objective lens 46, passes through the hole in the hole mirror 45, transmits through the focusing lens 47, transmits through the relay lens 48, and is imaged by the imaging lens 49 on the light receiving surface of the image sensor 51 of the imaging device 50.

[0057] (Imaging device 50) The imaging device 50 includes an image sensor 51 that receives return light of the illumination light guided from the fundus Ef of the subject's eye E through the photographing optical system 40. The imaging device 50 is controlled by a control unit 100 described later and is capable of outputting a result of receiving the return light.

[0058] (Image Sensor 51) The image sensor 51 functions as a pixelated light receiver. The light receiving surface (detection surface, imaging surface) of the image sensor 51 can be disposed at a position that is approximately optically conjugate with the fundus Ef.

[0059] The light reception results by the image sensor 51 are captured and read out by a rolling shutter method. In some embodiments, a control unit 100 described below controls the reading of the light reception results by controlling the image sensor 51. In some embodiments, the image sensor 51 can automatically output the light reception results for a predetermined line together with information indicating the light reception position.

[0060] Such an image sensor 51 includes a CMOS image sensor. In this case, the image sensor 51 includes a plurality of pixels arranged two-dimensionally, a plurality of vertical signal lines, and a horizontal signal line. Each pixel includes a photodiode (light receiving element) and a capacitor. The plurality of vertical signal lines are provided for each pixel group in a column direction (vertical direction) perpendicular to the row direction (horizontal direction). Each vertical signal line is selectively electrically connected to a pixel group in which a charge corresponding to the light receiving result is accumulated. The horizontal signal line is selectively electrically connected to the plurality of vertical signal lines. Each pixel accumulates a charge corresponding to the light receiving result of the return light, and the accumulated charge is read out, for example, sequentially for each pixel group in the row direction. For example, a voltage corresponding to the charge accumulated in each pixel is supplied to the vertical signal line for each line in the row direction. The plurality of vertical signal lines are selectively electrically connected to the horizontal signal line. By performing the above-mentioned read operation for each line in the row direction sequentially in the vertical direction, it is possible to read out the light receiving results of the plurality of pixels arranged two-dimensionally.

[0061] A light receiving image corresponding to a desired virtual aperture shape extending in the row direction is obtained by capturing (reading) the light receiving result of the return light by the rolling shutter method for such an image sensor 51. Such control is disclosed, for example, in the specification of U.S. Patent No. 8,237,835.

[0062] 4 is a diagram illustrating the operation of the ophthalmologic apparatus 1 according to the first embodiment. FIG. 4 illustrates a schematic diagram of an illumination range IP of a slit-shaped illumination light irradiated onto the fundus Ef and a virtual aperture range OP on the light receiving surface SR of the image sensor 51.

[0063] For example, the control unit 100 described later deflects the slit-shaped illumination light formed by the illumination optical system 20 using the optical scanner 30. As a result, the irradiation range IP of the slit-shaped illumination light is sequentially moved in a direction (e.g., vertical direction) perpendicular to the slit direction (e.g., row direction, horizontal direction) on the fundus Ef.

[0064] On the light receiving surface SR of the image sensor 51, for example, a virtual aperture range OP is set by changing the pixels to be captured line by line by the control unit 100 described later. It is desirable that the aperture range OP is a light receiving range IP' of the return light of the illumination light on the light receiving surface SR or a range wider than the light receiving range IP'. For example, the control unit 100 described later executes movement control of the aperture range OP in synchronization with movement control of the irradiation range IP of the illumination light. This makes it possible to acquire a high-quality image of the fundus Ef with strong contrast with a simple configuration without being affected by unnecessary scattered light.

[0065] Figures 5 and 6 show schematic examples of control timing of the rolling shutter method for the image sensor 51. Figure 5 shows an example of the timing of readout control for the image sensor 51. Figure 6 shows the movement control timing of the illumination light irradiation range IP (light receiving range IP') superimposed on the readout control timing of Figure 5. In Figures 5 and 6, the horizontal axis represents the number of rows in the image sensor 51, and the vertical axis represents time.

[0066] 5 and 6, for convenience of explanation, the number of rows of the image sensor 51 is 1920, but the configuration according to the first embodiment is not limited to the number of rows. Also, in FIG. 6, for convenience of explanation, the slit width (width in the row direction) of the slit-shaped illumination light is 40 rows.

[0067] The row-direction readout control includes reset control, exposure control, charge transfer control, and output control. The reset control is a control for initializing the amount of charge accumulated in the pixels in the row direction. The exposure control is a control for shining light on the photodiode and accumulating a charge corresponding to the amount of received light in a capacitor. The charge transfer control is a control for transferring the amount of charge accumulated in the pixel to the vertical signal line. The output control is a control for outputting the amount of charge accumulated in a plurality of vertical signal lines via a horizontal signal line. That is, as shown in FIG. 5, the readout time T of the amount of charge accumulated in the pixels in the row direction is the sum of the time Tr required for the reset control, the time (exposure time) Te required for the exposure control, the time Tc required for the charge transfer control, and the time Tout required for the output control.

[0068] 5, the read (capture) start timing (start timing of time Tc) is shifted row by row to obtain the light reception results (amount of charge) accumulated in pixels in a desired range in the image sensor 51. For example, when the pixel range shown in FIG. 5 is an image for one frame, the frame rate FR is uniquely determined.

[0069] In this embodiment, the irradiation position on the fundus Ef of illumination light having a slit width corresponding to the number of rows is sequentially shifted in a direction corresponding to the column direction on the fundus Ef.

[0070] For example, as shown in Fig. 6, the irradiation position of the illumination light on the fundus Ef is shifted row by row in a direction corresponding to the column direction for each predetermined shift time Δt. The shift time Δt is obtained by dividing the exposure time Te of the pixel in the image sensor 51 by the slit width of the illumination light (for example, the number of rows of the slit width = 40) (Δt = Te / 40). In synchronization with the timing of moving the irradiation position, the timing of starting to read out each row of pixels is delayed and started for each shift time Δt. This makes it possible to obtain a high-quality image of the fundus Ef with strong contrast with simple control in a short time.

[0071] In some embodiments, image sensor 51 comprises one or more line sensors.

[0072] [Control system configuration] 2, the control system of the ophthalmic apparatus 1 is mainly configured with a control unit 100. Note that at least a part of the configuration of the control system may be included in the ophthalmic apparatus 1.

[0073] (Control unit 100) The control unit 100 controls each unit of the ophthalmic apparatus 1. The control unit 100 includes a main control unit 101 and a storage unit 102. The main control unit 101 includes a processor, and executes control processing of each unit of the ophthalmic apparatus 1 by executing processing according to a program stored in the storage unit 102.

[0074] (Main control unit 101) The main control unit 101 controls the light source 10, the moving mechanism 10D, the illumination optical system 20, the optical scanner 30, the imaging optical system 40, the imaging device 50, the data processing unit 200, and the voltage detection circuit 210.

[0075] The control of the light source 10 includes switching the light source on and off (or the wavelength region of the light) and changing the light amount of the light source.

[0076] The movement mechanism 10D uses a known mechanism to change at least one of the position and the orientation of the light source 10. The main control unit 101 can change at least one of the relative position and the relative orientation of the light source 10 with respect to the iris diaphragm 21 and the slit 22.

[0077] The control of the illumination optical system 20 includes the control of the moving mechanism 22D. The moving mechanism 22D moves the slit 22 in the optical axis direction of the illumination optical system 20. The main controller 101 controls the moving mechanism 22D in accordance with the state of the subject's eye E to place the slit 22 at a position corresponding to the state of the subject's eye E. The state of the subject's eye E includes the shape of the fundus Ef, the refractive power, and the axial length. The refractive power can be obtained from a known eye refractive power measuring device such as those disclosed in JP-A-61-293430 or JP-A-2010-259495. The axial length can be obtained from the measurement value of a known axial length measuring device or an optical coherence tomography.

[0078] For example, first control information in which the position of the slit 22 on the optical axis of the illumination optical system 20 is previously associated with the refractive power is stored in the storage unit 102. The main control unit 101 refers to the first control information to specify the position of the slit 22 corresponding to the refractive power, and controls the moving mechanism 22D so that the slit 22 is located at the specified position.

[0079] Here, the light amount distribution of the light passing through the opening formed in the slit 22 changes with the movement of the slit 22. At this time, as described above, the main control unit 101 can change the position and orientation of the light source 10 by controlling the movement mechanism 10D.

[0080] The control of the optical scanner 30 includes controlling the angle of the deflection surface that deflects the illumination light. By controlling the angle range of the deflection surface, it is possible to control the scan range (scan start position and scan end position). By controlling the speed at which the angle of the deflection surface is changed, it is possible to control the scan speed.

[0081] The control of the photographing optical system 40 includes the control of the moving mechanism 47D. The moving mechanism 47D moves the focusing lens 47 in the optical axis direction of the photographing optical system 40. The main control unit 101 can control the moving mechanism 47D based on the analysis result of the image acquired by using the image sensor 51. The main control unit 101 can also control the moving mechanism 47D based on the operation content of the user using the operation unit 110 described later.

[0082] The control of the imaging device 50 includes the control of the image sensor 51. The control of the image sensor 51 includes the control for reading out the light reception result by the rolling shutter method (for example, setting the light reception size corresponding to the size of the illumination pattern, etc.). The control of the image sensor 51 also includes reset control, exposure control, charge transfer control, output control, etc. It is possible to change the time Tr required for reset control, the time (exposure time) Te required for exposure control, the time Tc required for charge transfer control, the time Tout required for output control, etc.

[0083] The control of the data processing unit 200 includes various image processing and analysis processing for the light reception results obtained from the image sensor 51. The image processing includes noise removal processing for the light reception results, and brightness correction processing for making it easier to identify a specific part depicted in the light reception image based on the light reception results. The analysis processing includes processing for identifying the focus state.

[0084] The data processing unit 200 can form a light receiving image corresponding to an arbitrary aperture range based on the light receiving result read out from the image sensor 51 by the rolling shutter method. The data processing unit 200, as an image forming unit, can sequentially form light receiving images corresponding to the aperture range and form an image of the subject's eye E from the formed multiple light receiving images.

[0085] The data processing unit 200 includes a processor, and performs processing according to a program stored in a storage unit or the like to realize the above functions.

[0086] The voltage detection circuit 210 outputs a trigger signal to the image sensor 51 to instruct the start of capturing the light reception result based on the scanner position signal from the optical scanner 30, as described later. The deflection angle of the illumination light by the optical scanner 30 can be specified from the scanner position signal. The function of the voltage detection circuit 210 can be realized by a known comparator circuit. The control of such a voltage detection circuit 210 includes setting a threshold voltage for determining whether the deflection angle of the illumination light by the optical scanner 30 is a desired deflection angle based on the scanner position signal.

[0087] In some embodiments, the light source 10 includes two or more light sources. In this case, each of the two or more light sources is provided corresponding to two or more openings formed in the iris diaphragm 21. The main control unit 201 can change at least one of the position and the orientation (the orientation in the direction in which the light quantity distribution is maximized) of each light source by controlling a movement mechanism provided corresponding to each of the two or more light sources.

[0088] (Storage unit 102) The storage unit 102 stores various computer programs and data. The computer programs include a calculation program and a control program for controlling the ophthalmic apparatus 1.

[0089] (Operation unit 110) The operation unit 110 includes an operation device or an input device. The operation unit 110 includes buttons and switches (e.g., an operation handle, an operation knob, etc.) and operation devices (a mouse, a keyboard, etc.) provided on the ophthalmic apparatus 1. The operation unit 110 may also include any operation device or input device, such as a trackball, an operation panel, a switch, a button, or a dial.

[0090] (Display section 120) The display unit 120 displays the image of the subject's eye E generated by the data processing unit 200. The display unit 120 includes a display device such as a flat panel display such as an LCD (Liquid Crystal Display). The display unit 120 may also include various display devices such as a touch panel provided on the housing of the ophthalmologic apparatus 1.

[0091] It is not necessary for the operation unit 110 and the display unit 120 to be configured as separate devices. For example, it is possible to use a device in which a display function and an operation function are integrated, such as a touch panel. In that case, the operation unit 110 is configured to include this touch panel and a computer program. The operation content on the operation unit 110 is input to the control unit 100 as an electric signal. In addition, operations and information input may be performed using a graphical user interface (GUI) displayed on the display unit 120 and the operation unit 110. In some embodiments, the functions of the display unit 120 and the operation unit 110 are realized by a touch screen.

[0092] (Other configurations) In some embodiments, the ophthalmic apparatus 1 further includes a fixation projection system. For example, the optical path of the fixation projection system is coupled to the optical path of the photographing optical system 40 in the optical system configuration shown in FIG. 1. The fixation projection system can present an internal fixation target or an external fixation target to the subject's eye E. When presenting an internal fixation target to the subject's eye E, the fixation projection system includes an LCD that displays the internal fixation target under the control of the control unit 100, and projects the fixation light beam output from the LCD onto the fundus of the subject's eye E. The LCD is configured to be able to change the display position of the fixation target on its screen. By changing the display position of the fixation target on the LCD, it is possible to change the projection position of the fixation target on the fundus of the subject's eye E. The display position of the fixation target on the LCD can be specified by the user using the operation unit 110.

[0093] In some embodiments, the ophthalmic apparatus 1 includes an alignment system. In some embodiments, the alignment system includes an XY alignment system and a Z alignment system. The XY alignment system is used to align the device optical system and the subject's eye E in a direction intersecting the optical axis of the device optical system (objective lens 46). The Z alignment system is used to align the device optical system and the subject's eye E in the direction of the optical axis of the ophthalmic apparatus 1 (objective lens 46).

[0094] For example, the XY alignment system projects a bright spot (a bright spot in the infrared region or near-infrared region) onto the subject's eye E. The data processing unit 200 acquires an anterior segment image of the subject's eye E onto which the bright spot is projected, and determines the displacement between the bright spot image depicted in the acquired anterior segment image and the alignment reference position. The control unit 100 relatively moves the device optical system and the subject's eye E in a direction intersecting with the direction of the optical axis using a moving mechanism (not shown) so that the determined displacement is cancelled.

[0095] For example, the Z alignment system projects alignment light in the infrared or near-infrared region from a position off the optical axis of the device optical system, and receives the alignment light reflected by the anterior segment of the subject's eye E. The data processing unit 200 specifies the distance of the subject's eye E from the device optical system based on the receiving position of the alignment light, which changes depending on the distance of the subject's eye E from the device optical system. The control unit 100 moves the device optical system and the subject's eye E relatively in the direction of the optical axis using a moving mechanism (not shown) so that the specified distance becomes the desired working distance.

[0096] In some embodiments, the function of the alignment system is realized by two or more anterior eye cameras arranged at a position off the optical axis of the device optical system. For example, as disclosed in JP 2013-248376 A, the data processing unit 200 analyzes anterior eye images of the subject eye E acquired substantially simultaneously by two or more anterior eye cameras, and specifies the three-dimensional position of the subject eye E using a known trigonometric method. The control unit 100 moves the device optical system and the subject eye E three-dimensionally relative to each other by a moving mechanism (not shown) so that the optical axis of the device optical system approximately coincides with the axis of the subject eye E and the distance of the device optical system to the subject eye E is a predetermined working distance.

[0097] As described above, the slit 22 (opening), the photographing site (fundus oculi Ef), and the image sensor 51 (light receiving surface) are disposed at positions that are approximately optically conjugate with each other in the ophthalmic apparatus 1. The ophthalmic apparatus 1 moves the light receiving opening in the image sensor 51 and the irradiation position of the illumination light in conjunction with each other, thereby making it possible to obtain a clear image of the photographing site while suppressing the influence of unnecessary scattered light.

[0098] In the ophthalmic apparatus 1 according to the first embodiment, the image sensor 51 receives and captures the return light of the illumination light at an appropriate timing, thereby eliminating the influence of unnecessary scattered light and improving the quality of the image of the subject's eye E acquired based on the light reception result. Therefore, in the first embodiment, the optical scanner 30 and the image sensor 51 are synchronized with high accuracy to improve the quality of the acquired image.

[0099] Fig. 7 is a schematic diagram for explaining the synchronous control of the ophthalmologic apparatus 1 according to the first embodiment. In Fig. 7, the same parts as those in Fig. 2 are given the same reference numerals, and the explanation will be omitted as appropriate.

[0100] As described above, the control unit 100 controls the deflection angle of the illumination light by the optical scanner 30 (the angle of the deflection plane relative to the reference angle). The control unit 100 controls the deflection angle of the illumination light by outputting a scanner control signal Scont to the optical scanner 30. For example, by outputting a scanner control signal Scont of a desired voltage level to the optical scanner 30, the angle of the deflection plane of the optical scanner 30 can be set to a desired deflection angle.

[0101] The optical scanner 30 can output a scanner position signal Spos corresponding to the angle of the deflection plane. For example, the scanner position signal Spos is a signal with a voltage level corresponding to the angle of the deflection plane. By identifying the voltage level of the scanner position signal Spos, it is possible to identify the angle of the deflection plane of the optical scanner 30 (the deflection angle of the illumination light by the optical scanner 30).

[0102] The voltage detection circuit 210 detects whether the deflection angle of the illumination light by the optical scanner 30 is a desired deflection angle based on the voltage level of the scanner position signal Spos from the optical scanner 30, and outputs a trigger signal Tr corresponding to the detection result to the image sensor 51. Specifically, the voltage detection circuit 210 compares the scanner position signal Spos with a first threshold voltage TH1, and outputs a trigger signal Tr of a voltage level corresponding to the comparison result between the scanner position signal Spos and the first threshold voltage TH1 to the image sensor 51.

[0103] The image sensor 51 starts acquiring the result of receiving the return light of the illumination light on the light receiving surface in synchronization with the change timing (e.g., rising edge) of the trigger signal Tr from the voltage detection circuit 210, and transfers the acquired light receiving result to the control unit 100.

[0104] [Operation] Next, the operation of the ophthalmologic apparatus 1 will be described.

[0105] Fig. 8 shows an example of the operation of the ophthalmic apparatus 1 according to the first embodiment. Fig. 8 is a sequence diagram showing the sequence of the example of the operation of the ophthalmic apparatus 1.

[0106] First, the control unit 100 outputs a scanner control signal Scont to the optical scanner 30 so as to deflect the illumination light at a desired deflection angle (SQ1).

[0107] In the optical scanner 30, the direction of the deflection plane is changed by a deflection angle corresponding to the scanner control signal Scont from the control unit 100 (SQ2). This makes it possible to illuminate a predetermined area of ​​the fundus Ef with the illumination light. The optical scanner 30 outputs a scanner position signal Spos corresponding to the deflection angle of the deflection plane (SQ3).

[0108] The voltage detection circuit 210 compares the scanner position signal Spos from the optical scanner 30 with a predetermined first threshold voltage TH1. This allows the voltage detection circuit 210 to detect whether or not to capture the result of receiving the return light of the illumination light by the image sensor 51, based on the deflection direction of the illumination light by the optical scanner 30 (SQ4).

[0109] The voltage detection circuit 210 compares the scanner position signal Spos from the optical scanner 30 with a predetermined first threshold voltage TH1, and outputs a trigger signal Tr with a voltage level according to the comparison result (SQ5).

[0110] For example, when the scanner position signal Spos is equal to or greater than the first threshold voltage TH1, a trigger signal Tr of the first power supply voltage level (L level) is output, and when the scanner position signal Spos is less than the first threshold voltage TH1, a trigger signal Tr of the second power supply voltage level (H level) is output. In this case, when the scanner position signal Spos is equal to or greater than the first threshold voltage TH1, the voltage detection circuit 210 outputs a trigger signal Tr of the L level to the image sensor 51.

[0111] Since the voltage level of the trigger signal Tr from the voltage detection circuit 210 does not change, the image sensor 51 does not start taking in the result of receiving the return light of the illumination light.

[0112] Next, the control unit 100 outputs a scanner control signal Scont to the optical scanner 30 so as to deflect the illumination light at the next desired deflection angle (SQ6). In some embodiments, the control unit 100 outputs the scanner control signal Scont to the optical scanner 30 at a predetermined time interval. In some embodiments, upon receiving a notification that the transfer of the light reception result from the image sensor 51 has been completed, the control unit 100 outputs a scanner control signal Scont to the optical scanner 30 so as to deflect the illumination light at the next desired deflection angle.

[0113] Similarly, in the optical scanner 30, the direction of the deflection surface is changed by a deflection angle corresponding to the scanner control signal Scont from the control unit 100 (SQ7). The optical scanner 30 outputs a scanner position signal Spos corresponding to the deflection angle of the deflection surface (SQ8).

[0114] Similar to SQ4, the voltage detection circuit 210 compares the scanner position signal Spos from the optical scanner 30 with the first threshold voltage TH1 to detect whether or not to capture the result of reception of the return light of the illumination light by the image sensor 51 (SQ9).

[0115] The voltage detection circuit 210 compares the scanner position signal Spos from the optical scanner 30 with a first threshold voltage TH1, and outputs a trigger signal Tr with a voltage level according to the comparison result (SQ10).

[0116] In this case, when the scanner position signal Spos changes from a voltage level equal to or higher than the first threshold voltage TH1 to a voltage level lower than the first threshold voltage TH1, the voltage detection circuit 210 outputs a trigger signal Tr to the image sensor 51, which changes from an L level to an H level.

[0117] The image sensor 51 starts acquiring the result of receiving the return light of the illumination light on a predetermined line (see FIG. 6) in synchronization with the rising edge of the trigger signal Tr from the voltage detection circuit 210 changing from L level to H level (SQ11).

[0118] The image sensor 51 transfers the light reception result to the control unit 100 at a predetermined timing (SQ12). The predetermined timing may be a timing determined in advance, or may be a timing determined by the end timing of the acquisition of the predetermined light reception result. In some embodiments, the control unit 100 controls the image sensor 51 to read out, so that the image sensor 51 transfers the light reception result to the control unit 100.

[0119] In order to divide and sequentially illuminate a predetermined illumination area of ​​the fundus Ef with illumination light, the above-described series of controls is repeated for each illumination area.

[0120] 9 shows an example of the timing of synchronous control of the ophthalmic apparatus 1 according to the first embodiment. FIG. 9 shows a schematic relationship between the scanner control signal Scont, the scanner position signal Spos, the trigger signal Tr, and the timing at which the image sensor 51 starts acquiring the light reception result.

[0121] 9, an example of the timing of the scanner control signal Scont is shown in a first timing diagram in which the vertical axis represents the voltage level of the scanner control signal Scont and the horizontal axis represents time t. Also, an example of the timing of the scanner position signal Spos is shown in a second timing diagram in which the vertical axis represents the voltage level of the scanner position signal Spos and the horizontal axis represents time t. Furthermore, an example of the timing of the trigger signal Tr is shown in a third timing diagram in which the vertical axis represents the voltage level of the trigger signal Tr and the horizontal axis represents time t.

[0122] The control unit 100 sequentially changes the illumination area by sequentially outputting the scanner control signal Scont so as to sequentially illuminate a predetermined photographing area on the fundus Ef as shown in Fig. 6. For example, the control unit 100 sequentially outputs the scanner control signal Scont to the optical scanner 30 as shown in Fig. 9.

[0123] The optical scanner 30 changes the deflection plane so that the deflection angle corresponds to the scanner control signal Scont from the control unit 100. At this time, the optical scanner 30 changes the deflection plane after a predetermined delay time Δdt has elapsed with respect to the scanner control signal Scont. The optical scanner 30 outputs a scanner position signal Spos corresponding to the deflection angle of the deflection plane.

[0124] As described above, the voltage detection circuit 210 compares the voltage level of the scanner position signal Spos with the first threshold voltage TH1, and outputs a trigger signal Tr of a voltage level according to the comparison result to the image sensor 51. When the voltage level of the scanner position signal Spos changes from a voltage level equal to or higher than the first threshold voltage TH1 to a voltage level lower than the first threshold voltage TH1, the voltage detection circuit 210 changes the voltage level of the trigger signal Tr, and outputs an H-level trigger signal Tr.

[0125] The image sensor 51 starts capturing the result of receiving the return light of the illumination light in synchronization with the rising edge of the trigger signal Tr from the voltage detection circuit 210. For example, during the capture period, as shown in Fig. 6, reset control is performed in the period Tr, exposure control is performed in the period Te, charge transfer control is performed in the period Tc, and output control is performed in the period Tout.

[0126] As described above, the timing of capturing the result of receiving the return light of the illumination light by the image sensor 51 can be controlled in synchronization with the scanner position signal Spos of the optical scanner 30, which is controllable by the scanner control signal Scont from the control unit 100. This makes it possible to receive and capture the return light of the illumination light in high-precision synchronization with the illumination area of ​​the illumination light, thereby eliminating the influence of unnecessary scattered light and improving the image quality of the image of the subject's eye E to be obtained.

[0127] The voltage detection circuit 210 is an example of a "first voltage detection circuit" according to the embodiment.

[0128] <Second embodiment> The configuration of the ophthalmic apparatus according to the embodiment is not limited to the configuration of the ophthalmic apparatus 1 according to the first embodiment. In the ophthalmic apparatus according to the second embodiment, the optical scanner 30, the image sensor 51, and the light source 10 are synchronized with high accuracy to obtain an image of the subject's eye E with high image quality.

[0129] The ophthalmic apparatus according to the second embodiment will be described below, focusing on the differences from the ophthalmic apparatus 1 according to the first embodiment.

[0130] [Optical system configuration] The configuration of the optical system of the ophthalmic apparatus according to the second embodiment is similar to the configuration of the optical system of the ophthalmic apparatus 1 according to the first embodiment.

[0131] [Control system configuration] Fig. 10 is a block diagram showing an example of the configuration of a control system of an ophthalmic apparatus according to the second embodiment. In Fig. 10, the same components as those in Fig. 2 are given the same reference numerals, and the description thereof will be omitted as appropriate.

[0132] The configuration of the control system of the ophthalmic apparatus according to the second embodiment differs from the configuration of the control system of the ophthalmic apparatus 1 according to the first embodiment in that a voltage detection circuit 210a is provided instead of the voltage detection circuit 210.

[0133] The voltage detection circuit 210a has, in addition to the functions of the voltage detection circuit 210, a voltage detection function for controlling the light source 10 and a function for outputting a light source control signal to the light source 10. The voltage detection circuit 210a outputs a light source control signal LScont for controlling the light source 10 on and off in synchronization with a change in the scanner position signal Spos.

[0134] Fig. 11 is a schematic diagram for explaining synchronous control of an ophthalmic apparatus according to the second embodiment. In Fig. 11, the same parts as those in Fig. 7 or 10 are given the same reference numerals, and the explanation thereof will be omitted as appropriate.

[0135] The voltage detection circuit 210a includes a first voltage detection circuit 211a and a second voltage detection circuit 212a. The first voltage detection circuit 211a has the same function as the voltage detection circuit 210 in the first embodiment. That is, the first voltage detection circuit 211a detects whether the deflection angle of the illumination light by the optical scanner 30 is a desired deflection angle based on the voltage level of the scanner position signal Spos from the optical scanner 30, and outputs a trigger signal Tr corresponding to the detection result to the image sensor 51. Specifically, the first voltage detection circuit 211a compares the scanner position signal Spos with a first threshold voltage TH1, and outputs a trigger signal Tr of a voltage level corresponding to the comparison result between the scanner position signal Spos and the first threshold voltage TH1 to the image sensor 51.

[0136] The second voltage detection circuit 212a detects whether the deflection angle of the illumination light by the optical scanner 30 is a desired deflection angle based on the voltage level of the scanner position signal Spos, and outputs a light source control signal LScont corresponding to the detection result to the light source 10. Specifically, the second voltage detection circuit 212a compares the scanner position signal Spos with a second threshold voltage TH2, and outputs a light source control signal LScont of a voltage level corresponding to the comparison result between the scanner position signal Spos and the second threshold voltage TH2 to the light source 10. For example, when the scanner position signal Spos is equal to or higher than the second threshold voltage TH2, the second voltage detection circuit 212a outputs an L-level light source control signal LScont. The second threshold voltage TH2 is, for example, a threshold voltage for switching the light source 10 from an off state to an on state.

[0137] Moreover, the second voltage detection circuit 212a compares the scanner position signal Spos with a third threshold voltage TH3, and outputs a light source control signal LScont of a voltage level corresponding to the comparison result between the scanner position signal Spos and the third threshold voltage TH3 to the light source 10. For example, when the scanner position signal Spos is less than the third threshold voltage TH3, the second voltage detection circuit 212a outputs an L-level light source control signal LScont. The third threshold voltage TH3 is, for example, a threshold voltage for switching the light source 10 from an on state to an off state.

[0138] When the scanner position signal Spos is less than the second threshold voltage TH2 and is equal to or greater than the third threshold voltage TH3, the second voltage detection circuit 212a outputs an H-level light source control signal LScont.

[0139] The function of the second voltage detection circuit 212a can be realized by, for example, one or more known comparator circuits and an RS-flip-flop circuit. In order to capture the light reception result by the image sensor 51 during the period when the light source 10 is in the on state, the first threshold voltage TH1 may be a voltage between the second threshold voltage TH2 and the third threshold voltage TH3. In some embodiments, the voltage level of the first threshold voltage TH1 is approximately equal to the voltage level of the second threshold voltage TH2.

[0140] As in the first embodiment, the image sensor 51 starts acquiring the light reception results of the return light of the illumination light on the light receiving surface in synchronization with the change timing (e.g., the rising edge) of the trigger signal Tr from the first voltage detection circuit 211a, and transfers the acquired light reception results to the control unit 100.

[0141] The light source 10 is switched from the OFF state (non-illuminated state) to the ON state (illuminated state) in synchronization with a first change timing (e.g., a rising edge) of the light source control signal LScont from the second voltage detection circuit 212a. The light source 10 is switched from the ON state to the OFF state in synchronization with a second change timing (e.g., a falling edge) of the light source control signal LScont from the second voltage detection circuit 212a.

[0142] [Operation] Next, the operation of the ophthalmologic apparatus according to the second embodiment will be described.

[0143] Fig. 12 shows an example of the operation of the ophthalmic apparatus according to the second embodiment. Fig. 12 is a sequence diagram showing the sequence of the example of the operation of the ophthalmic apparatus according to the second embodiment. Note that the following control is performed when the light source 10 is in an off state.

[0144] First, similarly to SQ1, the control unit 100 outputs the scanner control signal Scont to the optical scanner 30 so as to deflect the illumination light at a desired deflection angle (SQ21).

[0145] In the optical scanner 30, the direction of the deflection plane is changed by a deflection angle corresponding to the scanner control signal Scont from the control unit 100, similar to SQ2 (SQ22). The optical scanner 30 outputs a scanner position signal Spos corresponding to the deflection angle of the deflection plane, similar to SQ3 (SQ23).

[0146] When the voltage level of the scanner position signal Spos changes from a voltage level equal to or higher than the second threshold voltage TH2 to a voltage level lower than the second threshold voltage TH2 (but equal to or higher than the first threshold voltage TH1), the first voltage detection circuit 211a does not change the voltage level of the trigger signal Tr, and the second voltage detection circuit 212a changes the voltage level of the light source control signal LScont (SQ24). The second voltage detection circuit 212a outputs the light source control signal LScont, which has changed to H level, to the light source 10 (SQ25).

[0147] The light source 10 is switched from the OFF state to the ON state in synchronization with the change timing (rising edge) of the light source control signal LScont from the second voltage detection circuit 212a (SQ26).

[0148] For example, at a predetermined time interval from SQ21, the control unit 100 outputs a scanner control signal Scont to the optical scanner 30 so as to deflect the illumination light at the next desired deflection angle (SQ27). In the optical scanner 30, the direction of the deflection plane is changed at a deflection angle corresponding to the scanner control signal Scont from the control unit 100 (SQ28). The optical scanner 30 outputs a scanner position signal Spos corresponding to the deflection angle of the deflection plane (SQ29).

[0149] When the voltage level of the scanner position signal Spos changes from a voltage level equal to or higher than the first threshold voltage TH1 to a voltage level lower than the first threshold voltage TH1 (but higher than the third threshold voltage TH3), the first voltage detection circuit 211a changes the voltage level of the trigger signal Tr, and the second voltage detection circuit 212a does not change the voltage level of the light source control signal LScont (SQ30). The first voltage detection circuit 211a outputs the trigger signal Tr, which has changed to H level, to the image sensor 51 (SQ31).

[0150] The image sensor 51 starts taking in the results of receiving the return light of the illumination light on a predetermined line in synchronization with the rising edge of the trigger signal Tr from the voltage detection circuit 210 (SQ32).

[0151] The image sensor 51 transfers the captured light reception result to the control unit 100 at a predetermined timing (SQ33).

[0152] Thereafter, in the same manner, the above series of controls are repeated for each illumination area in order to divide and sequentially illuminate a predetermined illumination area of ​​the fundus Ef with the illumination light.

[0153] Thereafter, for example, the control unit 100 outputs a scanner control signal Scont to the optical scanner 30 so as to deflect the illumination light at the next desired deflection angle (SQ34). In the optical scanner 30, the direction of the deflection plane is changed at a deflection angle corresponding to the scanner control signal Scont from the control unit 100 (SQ35). The optical scanner 30 outputs a scanner position signal Spos corresponding to the deflection angle of the deflection plane (SQ36).

[0154] When the voltage level of the scanner position signal Spos changes from a voltage level equal to or higher than the third threshold voltage TH3 to a voltage level lower than the third threshold voltage TH3, the first voltage detection circuit 211a does not change the voltage level of the trigger signal Tr, and the second voltage detection circuit 212a changes the voltage level of the light source control signal LScont (SQ37). The second voltage detection circuit 212a outputs the light source control signal LScont, which has changed to the L level, to the light source 10 (SQ38).

[0155] The light source 10 is switched from the on state to the off state in synchronization with the change timing (falling edge) of the light source control signal LScont from the second voltage detection circuit 212a (SQ39).

[0156] Fig. 13 shows an example of the timing of synchronous control of the ophthalmic apparatus 2 according to the second embodiment. Fig. 13 shows a schematic relationship between the scanner control signal Scont, the scanner position signal Spos, the trigger signal Tr, the light source control signal LScont, and the timing at which the image sensor 51 starts acquiring the light reception result.

[0157] In Fig. 13, a first timing diagram shows an example of the timing of the scanner control signal Scont. A second timing diagram shows an example of the timing of the scanner position signal Spos. A third timing diagram shows an example of the timing of the trigger signal Tr. A third timing diagram shows an example of the timing of the light source control signal LScont, with the vertical axis representing the voltage level of the light source control signal LScont and the horizontal axis representing time 4.

[0158] The control unit 100 sequentially changes the illumination area by sequentially outputting the scanner control signal Scont so as to sequentially illuminate a predetermined photographing area on the fundus Ef as shown in Fig. 6. For example, the control unit 100 sequentially outputs the scanner control signal Scont to the optical scanner 30 as shown in Fig. 13.

[0159] The optical scanner 30 changes the deflection plane so that the deflection angle corresponds to the scanner control signal Scont from the control unit 100. At this time, the optical scanner 30 changes the deflection plane after a predetermined delay time Δdt has elapsed with respect to the scanner control signal Scont. The optical scanner 30 outputs a scanner position signal Spos corresponding to the deflection angle of the deflection plane.

[0160] First, as described above, the second voltage detection circuit 212a compares the voltage level of the scanner position signal Spos with the second threshold voltage TH2, and outputs the light source control signal LScont of a voltage level according to the comparison result to the light source 10. When the voltage level of the scanner position signal Spos changes from a voltage level equal to or higher than the second threshold voltage TH2 to a voltage level lower than the second threshold voltage TH2, the second voltage detection circuit 212a changes the voltage level of the light source control signal LScont, and outputs an H-level light source control signal LScont.

[0161] The light source 10 is switched from the off state to the on state in synchronization with the rising edge of the light source control signal LScont from the second voltage detection circuit 212a.

[0162] Next, as described above, the first voltage detection circuit 211a compares the voltage level of the scanner position signal Spos with the first threshold voltage TH1, and outputs a trigger signal Tr of a voltage level according to the comparison result to the image sensor 51. When the voltage level of the scanner position signal Spos changes from a voltage level equal to or higher than the first threshold voltage TH1 to a voltage level lower than the first threshold voltage TH1 (however, TH1>TH3), the first voltage detection circuit 211a changes the voltage level of the trigger signal Tr, and outputs an H-level trigger signal Tr.

[0163] The image sensor 51 starts capturing the result of receiving the return light of the illumination light in synchronization with the rising edge of the trigger signal Tr from the first voltage detection circuit 211a. For example, during the capture period, as shown in Fig. 6, reset control is performed in the period Tr, exposure control is performed in the period Te, charge transfer control is performed in the period Tc, and output control is performed in the period Tout.

[0164] For example, after the transfer of the light reception result by the image sensor 51 to the control unit 100 is completed, the control unit 100 outputs the scanner control signal Scont to the optical scanner 30 to change the direction of the deflection surface. At this time, the second voltage detection circuit 212a compares the voltage level of the scanner position signal Spos with the third threshold voltage TH3 as described above, and outputs the light source control signal LScont of a voltage level according to the comparison result to the light source 10. When the voltage level of the scanner position signal Spos changes from a voltage level equal to or higher than the third threshold voltage TH3 to a voltage level lower than the third threshold voltage TH3, the second voltage detection circuit 212a changes the voltage level of the light source control signal LScont and outputs the light source control signal LScont of an L level.

[0165] The light source 10 is switched from the on state to the off state in synchronization with the falling edge of the light source control signal LScont from the second voltage detection circuit 212a.

[0166] In the second embodiment, the case where the light source 10 is switched to the OFF state based on the voltage level of the scanner position signal Spos has been described, but the configuration according to the embodiment is not limited to this. For example, the control unit 100 may control the light source 10 to switch it to the OFF state after a predetermined period has elapsed since the light source 10 was switched to the ON state based on the voltage level of the scanner position signal Spos.

[0167] As described above, the timing of taking in the result of receiving the return light of the illumination light from the image sensor 51 and the timing of irradiating the illumination light from the light source 10 can be controlled in synchronization with the scanner position signal Spos of the optical scanner 30, which can be controlled by the scanner control signal Scont from the control unit 100. This makes it possible to receive and take in the return light of the illumination light in high precision synchronization with the illumination area of ​​the illumination light, thereby eliminating the influence of unnecessary scattered light and improving the quality of the image of the subject's eye E to be obtained.

[0168] In addition, the image sensor 51 can start and finish capturing the light receiving results while the light source 10 is on, thereby reliably eliminating the effects of unnecessary scattered light and further improving the image quality of the image of the test eye E.

[0169] The first voltage detection circuit 211a is an example of a "first voltage detection circuit" according to an embodiment. The second voltage detection circuit 212a is an example of a "second voltage detection circuit" according to an embodiment. The second threshold voltage TH2 or the third threshold voltage TH3 is an example of a "second threshold voltage" according to an embodiment.

[0170] [Actions and Effects] The functions and effects of an ophthalmic apparatus, a control method thereof, and a program according to an embodiment will be described.

[0171] An ophthalmic apparatus (1) according to some embodiments includes a light source (10), an illumination optical system (20), an optical scanner (30), an imaging optical system (40), and a control unit (100, main control unit 101). The illumination optical system generates slit-shaped illumination light using light from the light source. The optical scanner deflects the illumination light and guides it to the fundus (Ef) of the subject's eye (E). The imaging optical system guides the return light of the illumination light from the fundus to an image sensor (51) that captures the light reception results of an area of ​​the light receiving surface corresponding to the illumination area of ​​the illumination light on the fundus by a rolling shutter method. The control unit controls the deflection angle of the illumination light by the optical scanner. The optical scanner outputs a scanner position signal (Spos) corresponding to the deflection angle of the illumination light. The image sensor starts to capture the light reception results of the return light in synchronization with the scanner position signal.

[0172] With this configuration, the optical scanner and image sensor can be synchronized with high precision using a simple configuration, thereby preventing the incorporation of unnecessary scattered light reception results and making it possible to obtain a high-quality image of the test eye formed based on the light reception results of the image sensor.

[0173] Some embodiments include a first voltage detection circuit (voltage detection circuit 210, first voltage detection circuit 211a) that changes a trigger signal (Tr) depending on the result of comparing the scanner position signal with a first threshold voltage (TH1), and the image sensor starts capturing the light reception result in synchronization with the change in the trigger signal.

[0174] According to this configuration, the trigger signal is changed based on the voltage level of the scanner position signal, and the image sensor starts to capture the light reception results in synchronization with the change in the trigger signal, making it possible to synchronize the optical scanner and image sensor with high precision using a simple configuration.

[0175] In some embodiments, the control unit outputs a scanner control signal (Scont) to the optical scanner, and deflects the illumination light at a deflection angle corresponding to the scanner control signal.

[0176] According to this configuration, a scanner position signal corresponding to the deflection angle can be generated by the scanner control signal, so that it becomes possible to start capturing the light reception results by the image sensor in synchronization with the scanner control signal from the control unit.

[0177] In some embodiments, the light source is switched from an on state to an off state or from an off state to an on state in synchronization with the scanner position signal.

[0178] With this configuration, the optical scanner, image sensor, and light source can be synchronized with high precision using a simple configuration, thereby preventing the capture of unnecessary scattered light reception results and making it possible to obtain a high-quality image of the test eye formed based on the light reception results of the image sensor.

[0179] Some embodiments include a second voltage detection circuit (212a) that changes a light source control signal (LScont) for controlling the light source on and off depending on the result of comparing the scanner position signal with a second threshold voltage (TH2, third threshold voltage TH3), and the light source is switched from an on state to an off state or from an off state to an on state in synchronization with the change in the light source control signal.

[0180] According to this configuration, the light source control signal is changed based on the voltage level of the scanner position signal, and the light source is controlled to be turned on and off in synchronization with the change in the light source control signal, making it possible to synchronize the optical scanner, image sensor, and light source with high precision using a simple configuration.

[0181] In some embodiments, the image sensor starts capturing the light receiving results and stops capturing the light receiving results during a period when the light source is in an on state.

[0182] According to such a configuration, the influence of unnecessary scattered light can be reliably eliminated, and the image quality of the image of the subject's eye can be further improved.

[0183] In some embodiments, the image sensor is a CMOS image sensor.

[0184] According to this configuration, the optical scanner and the image sensor can be synchronized with high accuracy with a simple configuration and at low cost.

[0185] A method for controlling an ophthalmic apparatus (1) according to some embodiments includes a light source (10), an illumination optical system (20) for generating slit-shaped illumination light using light from the light source, an optical scanner (30) for deflecting the illumination light and directing it to a fundus (Ef) of an eye (E) to be examined, an imaging optical system (40) for directing return light of the illumination light from the fundus to an image sensor (51) for capturing, by a rolling shutter method, a light reception result of an area of ​​a light receiving surface corresponding to an illumination area of ​​the illumination light on the fundus moved by the optical scanner, and a control unit (100, main control unit 101) for controlling a deflection angle of the illumination light by the optical scanner. The control method for the ophthalmic apparatus includes a first output step in which the optical scanner outputs a scanner position signal (Spos) corresponding to the deflection angle of the illumination light, and a light reception result acquisition step in which the image sensor starts capturing a light reception result of the return light in synchronization with the scanner position signal.

[0186] According to this method, the configuration of the ophthalmic apparatus can be simplified while the optical scanner and image sensor can be synchronized with high precision, thereby preventing the incorporation of unnecessary scattered light reception results and making it possible to obtain a high-quality image of the test eye formed based on the light reception results of the image sensor.

[0187] Some embodiments include a first voltage detection step of changing the scanner position signal depending on a comparison result between the scanner position signal and a first threshold voltage (TH1), and the light reception result acquisition step includes an image sensor starting to capture the light reception result in synchronization with the change in the scanner position signal.

[0188] According to this method, the trigger signal is changed based on the voltage level of the scanner position signal, and the image sensor starts to capture the light reception results in synchronization with the change in the trigger signal, thereby making it possible to synchronize the optical scanner and image sensor with high precision while simplifying the configuration of the ophthalmic apparatus.

[0189] Some embodiments include a second output step in which the control unit outputs a scanner control signal (Scont) to the optical scanner, and the optical scanner deflects the illumination light at a deflection angle corresponding to the scanner control signal.

[0190] According to this method, a scanner position signal corresponding to the deflection angle can be generated by the scanner control signal, so that it becomes possible to start capturing the light reception results by the image sensor in synchronization with the scanner control signal from the control unit.

[0191] Some embodiments include a light source control step of switching the light source from an on state to an off state or from an off state to an on state in synchronization with the scanner position signal.

[0192] According to this method, the configuration of the ophthalmic apparatus can be simplified while the optical scanner, image sensor, and light source can be synchronized with high precision, thereby preventing the incorporation of unnecessary scattered light reception results and making it possible to obtain a high-quality image of the test eye formed based on the light reception results of the image sensor.

[0193] Some embodiments include a second voltage detection step of changing a light source control signal (LScont) for controlling the light source on and off depending on a comparison result between the scanner position signal and a second threshold voltage (TH2, a third threshold voltage TH3), and the light source control step switches the light source from an on state to an off state or from an off state to an on state in synchronization with the change in the light source control signal.

[0194] According to this method, the light source control signal is changed based on the voltage level of the scanner position signal, and the light source is controlled to be turned on and off in synchronization with the change in the light source control signal, thereby making it possible to synchronize the optical scanner, image sensor, and light source with high precision while simplifying the configuration of the ophthalmic apparatus.

[0195] In some embodiments, in the light reception result acquisition step, the image sensor starts acquiring the light reception result while the light source is in an on-state, and ends acquiring the light reception result.

[0196] According to such a method, the influence of unnecessary scattered light can be reliably eliminated, and the image quality of the image of the subject's eye can be further improved.

[0197] In some embodiments, the image sensor is a CMOS image sensor.

[0198] According to this method, it is possible to simplify the configuration of the ophthalmic apparatus and to synchronize the optical scanner and the image sensor with high accuracy at low cost.

[0199] Some embodiments are programs for causing a computer to execute each step of any of the above-described methods for controlling an ophthalmic apparatus.

[0200] Such a program enables the optical scanner and image sensor to be synchronized with high precision using a simple configuration, thereby preventing the reception results of unnecessary scattered light from being captured and making it possible to obtain a high-quality image of the test eye formed based on the reception results of the image sensor.

[0201] The above-described embodiment and its modified examples are merely examples for implementing the present invention. Those who wish to implement the present invention may make any modifications, omissions, additions, etc. within the scope of the gist of the present invention.

[0202] In the above-mentioned embodiment, the ophthalmic apparatus may have any function usable in the field of ophthalmology, such as an axial length measurement function, an intraocular pressure measurement function, an optical coherence tomography (OCT) function, and an ultrasonic examination function. The axial length measurement function may be realized by an optical coherence tomograph or the like. The axial length measurement function may measure the axial length of the subject's eye by projecting light onto the subject's eye and detecting return light from the fundus while adjusting the position of the optical system in the Z direction (front-back direction) relative to the subject's eye. The intraocular pressure measurement function is realized by a tonometer or the like. The OCT function is realized by an optical coherence tomograph or the like. The ultrasonic examination function is realized by an ultrasonic diagnostic device or the like. The present invention may also be applied to an apparatus (multifunction device) having two or more of these functions.

[0203] In some embodiments, a program for causing a computer to execute the above-mentioned method for controlling an ophthalmic device is provided. Such a program can be stored in any non-transitory recording medium that can be read by a computer. The recording medium may be an electronic medium that uses magnetism, light, magneto-optical, semiconductors, or the like. Typically, the recording medium is a magnetic tape, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, a solid state drive, or the like. In addition, the program can be transmitted and received via a network such as the Internet or a LAN. [Explanation of symbols]

[0204] 1 Ophthalmology equipment 10 light source 20 Illumination optical system 21 Iris Diaphragm 22 Slit 23, 41, 44, 48 Relay lenses 30 Optical Scanner 35 Projection optical system 40. Photographing Optical System 42 Black dot plate 43 Reflective Mirror 45 hole mirror 46 Objective Lens 47 Focusing Lens 49 Imaging Lens 50 Imaging device 51 Image Sensor 100 Control section 101 Main control unit 102 Storage section 210, 210a Voltage detection circuit 211a First voltage detection circuit 212a Second voltage detection circuit LScont Light source control signal Scont Scanner Control Signal Spos scanner position signal TH1 First threshold voltage TH2 Second threshold voltage TH3 Third threshold voltage E. Examined eye Ef Fundus

Claims

1. A light source; an illumination optical system including a slit configured to be movable in an optical axis direction according to a state of the subject's eye, the illumination optical system generating a slit-shaped illumination light by irradiating the slit with light from the light source; an optical scanner that deflects the illumination light and guides it to the fundus of the subject's eye; an imaging optical system that guides return light of the illumination light from the fundus to an image sensor that captures, by a rolling shutter method, a light reception result of an area of ​​a light receiving surface corresponding to an illumination area of ​​the illumination light on the fundus moved by the optical scanner; a control unit for controlling a deflection angle of the illumination light by the optical scanner; Including, At least one of a relative position and a relative orientation of the light source with respect to the slit can be changed with the movement of the slit, the optical scanner outputs a scanner position signal corresponding to a deflection angle of the illumination light; The image sensor starts acquiring the result of receiving the return light in synchronization with the scanner position signal.

2. a first voltage detection circuit that changes a trigger signal in response to a comparison result between the scanner position signal and a first threshold voltage; The image sensor starts acquiring the light reception result in synchronization with a change in the trigger signal.

2. An ophthalmic apparatus according to claim 1.

3. The control unit outputs a scanner control signal to the optical scanner and deflects the illumination light at a deflection angle corresponding to the scanner control signal.

3. An ophthalmic apparatus according to claim 1 or 2.

4. The light source is switched from an on state to an off state or from an off state to an on state in synchronization with the scanner position signal. The ophthalmic apparatus according to any one of claims 1 to 3.

5. a second voltage detection circuit that changes a light source control signal for controlling the light source to be turned on and off in response to a comparison result between the scanner position signal and a second threshold voltage; The light source is switched from an on state to an off state or from an off state to an on state in synchronization with a change in the light source control signal.

5. An ophthalmic apparatus according to claim 4.

6. The image sensor starts acquiring the light reception result during a period in which the light source is in an on state, and ends acquiring the light reception result.

6. An ophthalmic apparatus according to claim 5.

7. The image sensor is a CMOS image sensor. The ophthalmic apparatus according to any one of claims 1 to 6.

8. A light source; an illumination optical system including a slit configured to be movable in an optical axis direction according to a state of the subject's eye, the illumination optical system generating a slit-shaped illumination light by irradiating the slit with light from the light source; an optical scanner that deflects the illumination light and guides it to the fundus of the subject's eye; an imaging optical system that guides return light of the illumination light from the fundus to an image sensor that captures, by a rolling shutter method, a light reception result of an area of ​​a light receiving surface corresponding to an illumination area of ​​the illumination light on the fundus moved by the optical scanner; a control unit for controlling a deflection angle of the illumination light by the optical scanner; A control method for an ophthalmic apparatus, the control method being capable of changing at least one of a relative position and a relative orientation of the light source with respect to the slit in accordance with a movement of the slit, a first output step in which the optical scanner outputs a scanner position signal corresponding to a deflection angle of the illumination light; a light reception result acquisition step in which the image sensor starts acquiring a result of receiving the return light in synchronization with the scanner position signal; A method for controlling an ophthalmic device, comprising:

9. a first voltage detection step of changing a trigger signal in response to a comparison result between the scanner position signal and a first threshold voltage; The light receiving result acquisition step includes: The image sensor starts capturing the light reception result in synchronization with the change in the trigger signal. The method for controlling an ophthalmic apparatus according to claim 8 .

10. a second output step of the control unit outputting a scanner control signal to the optical scanner, The optical scanner deflects the illumination light at a deflection angle corresponding to the scanner control signal.

10. The method for controlling an ophthalmic apparatus according to claim 8 or 9.

11. A light source control step of switching the light source from an on state to an off state or from an off state to an on state in synchronization with the scanner position signal. The method for controlling an ophthalmic apparatus according to any one of claims 8 to 10.

12. a second voltage detection step of changing a light source control signal for controlling on / off of the light source according to a comparison result between the scanner position signal and a second threshold voltage; The light source control step includes: The light source is switched from an on state to an off state or from an off state to an on state in synchronization with a change in the light source control signal. The method for controlling an ophthalmic apparatus according to claim 11 .

13. In the light reception result acquisition step, the image sensor starts acquiring the light reception result while the light source is in an on-state, and ends acquiring the light reception result. The method for controlling an ophthalmic apparatus according to claim 12 .

14. The image sensor is a CMOS image sensor. The method for controlling an ophthalmic apparatus according to any one of claims 8 to 13.

15. A program for causing a computer to execute each step of the method for controlling an ophthalmic apparatus according to any one of claims 8 to 14.

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