JP2017104319A - Ophthalmologic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmologic apparatus configured simply without using a dichroic mirror.SOLUTION: The ophthalmologic apparatus includes: scanning means for scanning a measuring beam on a subject's eye; detection means for detecting return light from the subject's eye to which the measuring beam is applied via an objective lens; fixation target display means for displaying a fixation target prompting a subject to visually fix the subject's eye; and fixation target reflection means for reflecting the fixation target in a direction in parallel to an optical axis of the objective lens. When a reflection plane of the scanning means is located at a scanning center in scanning the measuring beam, the fixation target reflection means is disposed flush with the reflection plane of the fixation target reflection means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ophthalmologic apparatus for imaging an eye to be examined.

  In recent years, an apparatus using an optical coherence tomography (OCT: Optical Coherence Tomography) that captures a tomographic image using interference by low-coherence light (hereinafter also referred to as an OCT apparatus) has been put into practical use. Since the OCT apparatus can capture a tomographic image with a resolution about the wavelength of light incident on the inspection object, a tomographic image of the inspection object can be obtained with high resolution. Therefore, the OCT apparatus is particularly useful as a fundus examination apparatus for obtaining a tomographic image of the retina located on the fundus. In the OCT apparatus, in order to obtain a tomographic image from a plurality of locations on the fundus, a mode in which low coherence light that is measurement light is scanned on the fundus is often used.

  On the other hand, a scanning laser ophthalmoscope (SLO: Scanning Laser Ophthalmoscope, hereinafter also referred to as an SLO apparatus) is also known as an apparatus for acquiring a fundus image. The SLO device scans a laser beam on the fundus and detects the reflected light through a pinhole or the like. In this case, the fundus can be observed with high contrast by using a confocal optical system. The SLO device is also used as a useful device for observing the state of the fundus as with the OCT device.

  On the other hand, generally, the OCT apparatus and the SLO apparatus are based on scanning of the fundus of measurement light, and the imaging time is relatively long. Therefore, in order to stabilize the fixation state where the subject gazes at a specific position for as long as possible during the imaging time, the fixation is performed simultaneously with the start of the measurement light scanning corresponding to the start of imaging. It is important to project the light onto the fundus. In the OCT apparatus or the SLO apparatus, a two-dimensional matrix LCD (Liquid Crystal Display) panel is used as a fixation lamp. In view of the importance of projecting the fixation lamp onto the fundus of the eye, gazing at the fixation lamp and irradiating the measurement light to the desired position, the optical path of the fixation lamp light from this LCD panel should be the same as the measurement optical path Is preferred. For this reason, a dichroic mirror is provided on the side closer to the eye to be examined than the galvanometer mirror as the scanning means, and a fixation lamp image is projected onto the fundus. Here, measurement light used in the OCT apparatus or SLO apparatus is often light in the infrared region (invisible or almost invisible), and the fixation lamp is often used with a wavelength such as green because it is visible. As described above, a dichroic mirror is used for separation or identification of each optical path as described above because of the ease of wavelength separation of each light and the ability to efficiently receive reflected light of measurement light. Patent Document 1 describes an OCT apparatus that uses a dichroic mirror to align the optical path in order to guide the measurement light scanned by the scanning unit and the fixation lamp to the eye to be examined as the same optical path.

JP 2009-279031 A

  Here, since the dichroic mirror has a complicated structure obtained by forming a multilayer film of dielectric thin films on the mirror surface of a transparent substrate, it is expensive and has restrictions on shape and the like. For this reason, it is desirable to refrain from using the ophthalmic apparatus as much as possible in order to reduce the cost.

  One of the objects of the present invention has been made in view of such problems, and is for guiding the optical path of measurement light scanned by the scanning means and the optical path of the fixation lamp to the eye to be examined as the same optical path. Thus, an ophthalmologic apparatus including a simple optical system for guiding these optical paths to the eye to be examined as the same optical path without using the dichroic mirror is provided.

In view of the above-described problems, the ophthalmologic apparatus of the present invention is
Scanning means for scanning the measuring light with the eye to be examined;
Detection means for detecting return light from the eye to be examined that has been irradiated with the measurement light via an objective lens;
Fixation target display means for displaying a fixation target for promoting fixation of the eye to be examined;
A fixation target reflecting means for reflecting the fixation target in a direction parallel to the optical axis of the objective lens,
The fixation target reflecting means is arranged to be in the same plane as the reflection surface of the fixation target reflecting means when the reflection surface of the scanning means is at the scanning center when scanning the measurement light. It is characterized by.

  According to the present invention, the optical path of the measurement light scanned by the scanning unit and the optical path of the fixation lamp are set as the same optical path, and these optical paths are used as the same optical path for the eye to be examined without using a dichroic mirror. An ophthalmologic apparatus configured with a simple optical system for guiding can be provided.

It is a figure explaining the optical structure of the fundus examination device in the example of the present invention. It is a figure explaining the fundus examination device in the example of the present invention. It is a figure explaining the positional relationship of a perforated mirror and a scanning means. It is a figure explaining the example which integrated the scanning means and the perforated mirror. It is a figure explaining the example which makes a fixation lamp and a measurement light emission part substantially coaxial. It is a figure explaining the other example of the positional relationship of the perforated mirror and scanning means in this invention.

  Embodiments of the present invention will be described below with reference to the drawings. The following examples do not limit the present invention related to the scope of claims, and all combinations of features described in the following examples are essential to the solution means of the present invention. Not exclusively.

  In the fundus examination apparatus according to the present embodiment, the fundus projection of the fixation lamp can be performed with a simple configuration. Hereinafter, the configuration of the fundus examination apparatus will be described for each item.

(Schematic configuration of the device)
A schematic configuration of the fundus examination apparatus according to the present embodiment will be described with reference to FIG.

  FIG. 2 is a side view of the fundus examination apparatus 200. The fundus examination apparatus includes an optical head 900, a stage unit 950, a base unit 951, a chin rest 323, a control unit 925, a storage unit 926, a monitor 928, and an input unit 929. The optical head 900 is a measurement optical system for capturing a two-dimensional image and a tomographic image of each of the anterior segment and fundus of the eye to be examined. The stage unit 950 supports the optical head 900 and enables the optical head 900 to be moved in the xyz direction in the drawing using a motor (not shown). The base unit 951 supports the stage unit 950 and incorporates a spectrometer described later.

  The control unit 925 is configured by, for example, a personal computer as the control unit of the stage unit, and performs tomographic image configuration and the like described later along with the control of the stage unit 950. The storage unit 926 functions as a storage unit for subject information, and simultaneously stores a program for tomographic imaging and the like, and includes a hard disk. A monitor 928 displays a tomographic image or the like as a display unit, and an input unit 929 is used when inputting an instruction or the like to a personal computer, and specifically includes a keyboard and a mouse. The chin rest 323 is a chin stand, and fixes the position of the subject's eye (examined eye) by fixing the subject's chin and forehead.

(Configuration of measurement optical system and spectrometer)
Next, the configuration of the measurement optical system and the spectroscope of this embodiment built in the optical head 900 will be described with reference to FIG.

  In the optical head 900, an objective lens 135-1 is disposed so as to face the eye 107 to be examined. The objective lens 135-1 is capable of focusing measurement light and fixation lamp light, which will be described later, on the fundus of the eye 107 to be examined, and enables projection of the fixation lamp light in accordance with the refractive power of the eye to be examined. An optical deflector for scanning the measurement light on the fundus on an optical path 353 opposite to the eye 107 to be examined as viewed from the objective lens 135-1 and passing through the objective lens 135-1 and the eye 107 to be examined. An XY scanner 1002 is arranged. In the figure, the XY scanner 1002 is shown as a single mirror, but scans the measurement light in the biaxial directions of the x axis and the y axis. An optical path 351 that is a reflection direction of the optical path 353 with respect to the XY scanner 1002 forms an optical path of the OCT optical system, and constitutes an optical path of measurement light for capturing a tomographic image of the fundus of the eye 107 to be examined. More specifically, the optical path 351 is used to obtain an interference signal for forming a tomographic image of the fundus of the eye to be examined.

  A lens 135-6 is disposed between the fiber end 131-5 that emits measurement light to the optical path 351 toward the XY scanner 1002 and the XY scanner 1002. The lens 135-6 guides the measurement light emitted from the fiber end 131-5 to a pupil position (not shown) of the eye 107 to be examined together with the objective lens 135-1, and forms an image on the fundus of the eye 107 to be examined. Configured to do. That is, the lens 135-6 guides the measurement light to the XY scanner 1002 as parallel light.

  Next, the configuration of the optical path from the light source 101, the reference optical system, and the spectroscope will be described. In this embodiment, light for obtaining measurement light and reference light is emitted from the light source 101. The light emitted from the light source 101 is guided to the optical coupler 131 by the optical fiber 131-1, and is divided into the reference light and the measurement light by the optical coupler 131. The optical fiber 131-1 is a single mode optical fiber that is connected to and integrated with the optical coupler 131 together with the other optical fibers 131-2 to 131-4.

  The reference optical system includes a mirror 132, a density filter 116, and a lens 135-7, and the reference light obtained from the optical coupler 131 is guided from the optical fiber 131-3. The optical coupler 131 and the accompanying components constitute a Michelson interferometer including the spectroscope 180.

  The measurement light is guided to the optical path 351 of the OCT optical system by the optical fiber 131-2, and irradiated to the fundus of the eye 107 to be examined through the optical path 351. The irradiated measurement light returns as return light through the same optical path due to reflection and scattering by the retina, enters the optical fiber 131-2 from the fiber end 131-5, and reaches the optical coupler 131.

  On the other hand, the reference light reaches the mirror 132 and is reflected through the optical fiber 131-3, the density filter 116, and the lens 135-7. Then, it returns on the same optical path and reaches the optical coupler 131 via the optical fiber 131-3.

  The measurement light (return light) and the reference light are combined by the optical coupler 131 and become interference light. The reference light is attenuated by the density filter 116, and the attenuation ratio is determined by the ratio of the reference light to the average measurement light, the sensitivity of the line sensor described later, and the like. Further, when the optical path length of the measurement light and the optical path length of the reference light are substantially the same, interference occurs between the lights. Therefore, the mirror 132 is held by a motor and a drive mechanism (not shown) so that the position of the mirror 132 can be adjusted in the optical axis direction, and the optical path length of the reference light can be adjusted to the optical path length of the measurement light that changes depending on the eye 107 to be examined. The interference light is guided to the spectroscope 180 via the optical fiber 131-4.

  In the optical fiber 131-2, a polarization adjusting unit 139-1 on the measurement light side is provided. Further, a polarization adjusting unit 139-2 on the reference light side is provided in the optical fiber 131-3. These polarization adjusting sections have several portions in which the optical fiber is routed in a loop shape, and twist the fiber by rotating the loop-shaped portion around the longitudinal direction of the fiber. As a result, the polarization states of the measurement light and the reference light can be adjusted and matched. In this apparatus, the polarization states of the measurement light and the reference light are adjusted and fixed in advance.

  The spectroscope 180 includes lenses 135-8 and 135-9, a diffraction grating 181, and a line sensor 182.

  The interference light emitted from the optical fiber 131-4 becomes parallel light via the lens 135-8, is then dispersed by the diffraction grating 181, and is imaged on the line sensor 182 by the lens 135-9.

  Next, the periphery of the light source 101 will be described. In this embodiment, an SLD (Super Luminescent Diode) that is a typical low-coherence light source is used as the light source 101. The center wavelength of the emitted light is 855 nm, and the wavelength bandwidth is about 30 nm. Here, the bandwidth is an important parameter because it affects the resolution of the obtained tomographic image in the optical axis direction. In addition, although the SLD is selected here as the type of light source, it is only necessary to emit low-coherence light, and ASE (Amplified Spontaneous Emission) or the like can also be used. In view of measuring the fundus, the center wavelength is preferably near infrared light. Moreover, since the center wavelength affects the lateral resolution of the obtained tomographic image, it is desirable that the center wavelength be as short as possible. For both reasons, the center wavelength was set to 855 nm.

  In this embodiment, a Michelson interferometer is used as the interferometer, but a Mach-Zehnder interferometer may be used. It is desirable to use a Mach-Zehnder interferometer when the light amount difference is relatively large and a Michelson interferometer when the light amount difference is relatively small according to the light amount difference between the measurement light and the reference light.

(Fixed optical system)
The fixation lamp 171 is composed of an LCD panel having light emitting portions in a two-dimensional matrix, that is, a liquid crystal display panel, and is arranged substantially perpendicular to the optical path 352 of the fixation lamp. The optical path 352 is angled with respect to the optical path 351 of the measurement light with the vicinity of the rotation center of the XY scanner 1002 as a center, and is arranged so as to have different incident angles. A lens 135-10 is disposed on the optical path 352. On the other hand, a perforated mirror 1001 that divides the measurement light and the fixation lamp light into pupils is provided outside the reflection surface of the XY scanner 1002. The fixation lamp light is guided to the perforated mirror 1001 as parallel light by the lens 135-10. Due to the presence of the lens 135-10, the in-focus state of the fixation lamp light by the objective lens 135-1 with respect to the fundus of the eye to be examined can be made the same as the in-focus state of the measurement light. That is, it is possible to present a clear fixation target to the subject during fixation. In the present embodiment, the above-described fixation lamp 171 constitutes a fixation target display unit that displays a fixation target that promotes fixation of the eye to be examined.

  The configuration of the perforated mirror 1001 will be described with reference to FIG. The perforated mirror 1001 includes an opening 1001a and a fixation lamp reflecting surface 1001b. The XY scanner 1002 is disposed in the opening 1001a, and the opening 1001a is larger than the reflection surface of the XY scanner 1002. Further, as shown in FIG. 1A, the fixation lamp reflecting surface 1001b of the perforated mirror 1001 guides fixation lamp light from the fixation lamp 171 to the optical path 353 which is the optical axis of the objective lens 135-1. It arrange | positions so that such an angle may be maintained. With this configuration, the fixation lamp light emitted from the fixation lamp 171 is projected onto the fundus through the lens 135-10, the fixation lamp reflecting surface 1001b, and the objective lens 135-1, without using a dichroic mirror having a complicated configuration. The Accordingly, the subject can fixate (gause) the fixation lamp 171.

  Here, the XY scanner 1002 will be described with reference to FIG. In this embodiment, a MEMS (Micro Electro Mechanical System) mirror is used as the XY scanner 1002. The MEMS mirror includes an x-direction rotation axis 1002a and a ym-direction rotation axis 1002b, and can perform two-dimensional scanning on the xy plane with a single mirror surface. The MEMS mirror can be integrally formed by a semiconductor process, and the perforated mirror 1001 can also be formed integrally with the MEMS mirror. Specifically, the fixation lamp reflecting surface 1001b is formed by the same semiconductor process on the outer side of each of the rotary shafts 1002a and 1002b provided on the outer peripheral portion of the MEMS mirror. As a result, a reflecting surface having a function as a perforated mirror substantially outside the MEMS mirror is obtained. In the present embodiment, the MEMS mirror functions as a micro electro mechanical system mirror configured integrally with the fixation target reflecting means.

  In the embodiment shown in FIG. 1A, the surface normal and the fixation lamp reflecting surface at the position of the deflection angle center of the XY scanner 1002 in the x direction (the measurement light is guided to the optical axis center of the objective lens at the center position). An angle is provided with respect to the surface normal of 1001b. That is, the reflecting surface of the XY scanner 1002 and the fixation lamp reflecting surface 1001b at the center of the rotation range when the XY scanner 1002 is rotated around the rotation axis 1002a in the x direction of the XY scanner 1002 are provided. An angular position forming a predetermined angle is set as a deflection angle center. In other words, in a state where the XY scanner 1002 is at a stationary position, the fixation lamp reflection surface 1001b is arranged so that the fixation lamp reflection surface 1001b is at an angular position offset from substantially parallel to the XY scanner 1002. Is determined.

  In this embodiment, the fixation lamp reflecting surface 1001b is manufactured integrally with the MEMS mirror by a semiconductor process. However, a mirror having a hole actually may be used as the hole mirror 1001, and the XY scanner 1002 may be disposed in the hole portion. In this embodiment, the fixation lamp reflection surface 1001b is disposed around the reflection surface of the XY scanner 1002. The fixation lamp reflecting surface 1001b is grasped as the second reflecting surface with respect to the reflecting surface of the scanner 1002. The rotation axis for rotating the reflection surface, that is, the rotation axis described above is arranged in the same plane as the second reflection surface.

  However, the arrangement of the reflecting surface and the second reflecting surface is not limited to the same plane. For example, it can be arranged as shown in FIG. 1B or FIG. 6 partially enlarged. FIG. 1 (b) is a schematic diagram of an optical system showing this configuration in the same manner as FIG. 1 (a). 6 shows a state in which the perforated mirror 1001 and the XY scanner 1002 are viewed from the side. In FIG. 6, the eye 107 to be examined, the optical path 352 of the fixation lamp, the optical path 351 of the measurement light, That is, the fixation lamp 171 is disposed. In this aspect, the fixation lamp reflecting surface 1001b (the perforated mirror 1001) is on the optical axis when the optical axis of the objective lens 135-1 is extended irrespective of the XY scanner 1002, and is relative to the eye 107 to be examined. Thus, it is arranged at a position behind the XY scanner 1002, in other words, at a far side. The perforated mirror 1001 is preferably a total reflection mirror. In this case, a part of the fixation lamp light guided to the eye 107 to be examined is blocked by the XY scanner 1002 and guided to the eye to be examined via an optical path outside the XY scanner 1002. Accordingly, the distance in the zm direction between the fixation lamp reflection surface 1001b and the XY scanner 1002, and the outer shape or size of the XY scanner 1002, the fixation lamp light reflected by the fixation lamp reflection surface 1001b is scattered by the XY scanner 1002. It is decided to meet no conditions.

  Further, the arrangement of the reflecting surface and the second reflecting surface can be reversed to this case. The form in this case is shown in FIG. That is, the fixation lamp reflecting surface 1001b (the perforated mirror 1001) is disposed on the optical axis of the objective lens 135-1 and in front of the XY scanner 1002 with respect to the eye 107 to be examined. In this case, the distance in the zm direction between the fixation lamp reflecting surface 1001b and the XY scanner 1002 and the outer shape or size of the opening 1001a are such that the measurement light scanned by the XY scanner 1002 is not blocked by the perforated mirror 1001. It is decided to satisfy. The XY scanner 1002 guides the measurement light to the objective lens 135-1 through the opening 1001a.

  The opening 1001a through which the measurement light passes can also be configured by a region that transmits the measurement light, such as a glass plate. In this case, as the perforated mirror 1001, a glass plate that transmits at least measurement light and having the fixation lamp reflecting surface 1001b formed by a technique such as chromium vapor deposition is used as a substantial perforated mirror.

  As described above, in the present invention, the fixation lamp reflecting surface 1001b reflects the fixation lamp light in a direction parallel to the optical axis of the objective lens 135-1, and guides it to the eye to be examined. Further, the positional relationship between the XY scanner 1002 and the perforated mirror 1001 is determined so that the measurement light deflected by the XY scanner 1002 and the reflected fixation lamp light are not shifted from each other. In determining the arrangement, it is essential that the fixation lamp light reflected by the fixation lamp reflecting surface 1001b is formed outside the optical path of the measurement light deflected by the XY scanner 1002. More specifically, the axis that coincides with the scanning center of the XY scanner 1002, that is, the optical axis of the measurement light, and the optical axis of the fixation lamp light reflected by the perforated mirror 1001 substantially coincide. Further, when viewed from the eye 107, the region through which the measurement light passes is around the optical axis of the measurement light, and the region through which the fixation lamp light guided to the eye to be inspected in order to promote fixation of the eye is passed. The position is farther from the optical axis with respect to the region. In this case, the optical path of the fixation lamp light is arranged around or outside the optical path of the measurement light.

In this embodiment, the fixation lamp reflection surface 1001b is formed on the entire circumference of the XY scanner 1002. However, there is no partial reflection surface, for example, the fixation lamp reflection surface 1001b has a U-shape. It is also possible to adopt a form. In this case, the optical path of the fixation lamp light is partially arranged outside or around the optical path of the measurement light.
In the present invention, the XY scanner 1002 deflects measurement light and also deflects fixation lamp light incident on the XY scanner 1002. For example, when a dichroic mirror is used in order to make the optical path of the measurement light and the fixation lamp light the same, the scanning means for the measurement light is arranged on the optical path separated from the fixation lamp light by the dichroic mirror. . Therefore, in the configuration using the dichroic mirror, the fixation lamp light cannot be deflected by the scanning unit.

  An example of the above-described XY scanner 1002 is a configuration in which the measurement light reflected by rotating the reflection surface is deflected and the measurement light 107 is scanned by the eye 107 via the objective lens 135-1. This corresponds to the scanning means in the invention. The configuration for obtaining the interference signal such as the above-described line sensor 182 and the control unit 925 that generates a tomographic image from the interference signal correspond to an image acquisition unit that acquires an image of the eye to be examined. The fixation lamp 171 corresponds to a fixation lamp display unit that displays a fixation target that promotes fixation of the eye to be examined, and the fixation lamp light corresponds to a fixation target projected from the fixation lamp display unit. The perforated mirror 1001 constitutes one aspect of the fixation target reflecting means in the present invention. The fixation target reflecting means reflects the fixation lamp light in a direction parallel to the optical axis of the objective lens 135-1, and guides the fixation lamp light to the eye to be examined. Further, a fixation lamp display means is arranged for the XY scanner 1002 so that the measurement light deflected by the XY scanner 1002 and the fixation lamp light reflected by the fixation target reflection means are not shifted from each other. The At the same time, the fixation lamp light reflected outside the optical path of the deflected measurement light forms an optical path.

(Tomographic imaging method)
Next, a tomographic image capturing method using the fundus examination apparatus 200 will be described. The fundus examination apparatus 200 can take a tomographic image of a desired site on the fundus of the eye 107 to be examined by controlling the XY scanner 1002.

  First, the measurement light obtained from the light source 101 is guided to the eye 107 to be examined through the optical path 351 of the OCT measurement system in FIG. At that time, the XY scanner 1002 is rotated about the rotation axis in the x direction in the drawing to scan the measurement light, and information on the predetermined number of images is acquired by the line sensor 182 from the imaging range in the y direction on the fundus. The luminance distribution on the line sensor 182 obtained at a certain position in the y direction is processed by FFT (Fast Fourier Transform).

  This linear luminance distribution obtained by FFT is converted to density or color information so as to be displayed on the monitor 928, and is called an A-scan image. A two-dimensional image in which the plurality of A-scan images are arranged in the y direction is referred to as a B-scan image. After capturing a plurality of A scan images for constructing one B scan image, moving the scan position in the x direction orthogonal to the y direction, and then performing the scan in the y direction again, a plurality of B scan images Get. By displaying a plurality of B-scan images or a three-dimensional tomographic image constructed from a plurality of B-scan images on the monitor 928, the examiner can use it for diagnosis of the eye to be examined.

  In the above-described embodiment, an example is shown in which an angle is provided between the deflection angle center of the XY scanner 1002 around the x axis (measurement light is guided to the center of the objective lens optical axis at the center position) and the fixation lamp reflecting surface 1001b. It was. However, the present invention is not limited to the configuration shown in this embodiment, and can be configured to have almost no angle, that is, the optical path 351 and the optical path 352 are coaxial.

  FIG. 5 shows the positional relationship between the fixation lamp 171 and the fiber end 131-5 in that case. FIG. 5 shows a front view of the fixation lamp 171 viewed from the XY scanner 1002 direction. As shown in FIG. 5, the fixation lamp 171 includes a light emitting unit 171a configured by LED chips arranged in a two-dimensional matrix on a substrate 171c. Further, a hole 171b is provided in the vicinity of the center of the matrix on the substrate 171c, and the fiber end 131-5 of the measurement light is disposed in the hole 171b, so that the optical path 351 and the optical path 352 are substantially coaxial. In this case, in this embodiment, the fixation target display means is a liquid crystal display panel, and the measurement light is guided to the reflecting surface from an arbitrary position in the liquid crystal display panel.

  In the above-described embodiment, an XY scanner is used as an optical deflector for fundus scanning with measurement light. However, the present invention is not limited to two-dimensional scanning, and by making B scanning possible as an embodiment for performing one-dimensional scanning, an apparatus with a simpler configuration can be obtained. In this case, it is possible to use not only the above-described MEMS scanner but also a polygon mirror or a galvanometer mirror by disposing the scanning means behind the fixation lamp reflecting surface. In this case, in the present embodiment, these mirrors scan the measurement light in the uniaxial direction as scanning means.

  In the present embodiment, only the angular relationship between the reflecting surface of the optical deflector and the perforated mirror is the difference from the first embodiment, and only this point will be described below. Since the other configuration is the same as that of the first embodiment, the description will be made using the reference numerals used in the first embodiment as necessary, and a duplicate description will be omitted.

  Hereinafter, the angular relationship between the reflecting surface of the optical deflector of this embodiment and the perforated mirror will be described with reference to FIG. In the first embodiment, around the x axis (in the ym-zm plane), the normal line at the center position of the XY scanner 1002 and the normal line of the fixation lamp reflecting surface 1001b are arranged to have a predetermined angle. Each normal was consistent in the other plane. On the other hand, in this embodiment, the normal of the fixation lamp reflecting surface 1001b is another predetermined angle around the ym axis (in the x-zm plane) with respect to the normal at the center position of the XY scanner 1002. It is arranged to have.

  As a result, among the light emitted from the fixation lamp 171, the light Lif-1 and the light Lif-3 reflected by the fixation lamp reflecting surface 1001b are substantially parallel to the optical axis of the optical path 353, and thus the objective lens 135- 1 is formed as an image fixed on the fundus. Further, the fixation lamp light Lif-2 incident on the XY scanner 1002 is reflected at an angle with respect to the optical axis of the optical path 353. This angle is configured so that the fixation lamp Light-2 does not enter the pupil of the eye (not shown) even if the reflecting surface rotates within the deflection angle range in which the XY scanner 1002 scans the measurement light on the ym axis. In other words, in the plane orthogonal to the plane on which the XY scanner 1002 rotates, the incident angle at the time of projecting the light onto the area where the light emitted from the fixation lamp 171 is reflected is the fixed angle reflected by the reflecting surface. The reflecting surface is arranged such that the viewing lamp light is at an angle that does not lead the eye to be examined through the objective lens.

  Therefore, the subject does not see the fixation lamp light deflected by the XY scanner, and the subject can more stably see the light from the fixation lamp 171.

  In the above-described embodiments, the case where the present invention is applied to an OCT apparatus used for fundus examination has been described as an example. However, the effects of the present invention are the same even in an SLO apparatus without an interferometer and a spectroscope. That is, the present invention can be applied to various ophthalmologic apparatuses that scan measurement light in a state in which fixation of the eye to be examined is promoted. Further, the acquired image is not limited to the fundus oculi, and images of various parts of the eye such as the anterior eye part may be acquired.

DESCRIPTION OF SYMBOLS 101 Light source 131 Optical coupler 132 Mirror 171 Fixation lamp 180 Spectroscope 200 Fundus inspection apparatus 900 Optical head 925 Personal computer 926 Hard disk 928 Monitor 950 Stage part 951 Base part 351 Measurement optical path 352 Optical path 353 Objective lens optical axis 1001 Hole mirror 1001b Fixation Light reflecting surface 1002 XY scanner

Claims (9)

Scanning means for scanning the measuring light with the eye to be examined;
Detection means for detecting return light from the eye to be examined that has been irradiated with the measurement light via an objective lens;
Fixation target display means for displaying a fixation target for promoting fixation of the eye to be examined;
A fixation target reflecting means for reflecting the fixation target in a direction parallel to the optical axis of the objective lens,
The fixation target reflecting means is arranged to be in the same plane as the reflection surface of the fixation target reflecting means when the reflection surface of the scanning means is at the scanning center when scanning the measurement light. Ophthalmic device characterized by   The fixation target reflection means has a second reflection surface arranged around the reflection surface of the scanning means, and the rotation axis of the reflection surface on which the scanning means reflects the fixation target and performs the scanning is The ophthalmic apparatus according to claim 1, wherein the ophthalmic apparatus is disposed in the same plane as the second reflecting surface. The optical axis for projecting the fixation target from the fixation target display means to the fixation target reflection means and the optical axis for guiding the measurement light to the reflection surface are parallel,
The ophthalmologic apparatus according to claim 1, wherein the fixation target display unit includes a liquid crystal display panel, and the measurement light is guided to the reflection surface from an arbitrary position on the liquid crystal display panel. Scanning means for scanning the measuring light with the eye to be examined;
Detection means for detecting return light from the eye to be examined that has been irradiated with the measurement light via an objective lens;
Fixation target display means for displaying a fixation target for promoting fixation of the eye to be examined;
A fixation target reflecting means for reflecting the fixation target in a direction parallel to the optical axis of the objective lens,
The fixation target reflecting means is a total reflection mirror disposed at a position farther than the scanning means with respect to the eye to be examined on the optical axis of the objective lens,
The ophthalmologic apparatus characterized in that the scanning means is disposed on the optical axis and blocks a part of the fixation target reflected by the fixation target reflection means. Scanning means for scanning the measuring light with the eye to be examined;
Detection means for detecting return light from the eye to be examined that has been irradiated with the measurement light via an objective lens;
Fixation target display means for displaying a fixation target for promoting fixation of the eye to be examined;
A fixation target reflecting means for reflecting the fixation target in a direction parallel to the optical axis of the objective lens,
The fixation target reflecting means is a perforated mirror disposed at a position closer to the eye to be examined on the optical axis of the objective lens than the scanning means,
The ophthalmic apparatus is characterized in that the measurement light having a size that does not scatter the measurement light when the scanning unit scans the measurement light passes or passes through the hole of the perforated mirror.   The ophthalmologic apparatus according to claim 5, wherein the scanning unit includes a polygon mirror or a galvanometer mirror that scans the measurement light in a uniaxial direction.   4. The ophthalmologic apparatus according to claim 1, wherein the scanning unit includes a microelectromechanical system mirror configured integrally with the fixation target reflecting unit. 5.   Incident when projecting the fixation target onto a region reflecting the fixation target from the fixation target display means within a plane orthogonal to a reflection surface on which the scanning means reflects the measurement light and performs the scanning 8. The reflecting surface is arranged such that an angle is an angle at which the fixation target reflected by the reflecting surface is not guided to the eye to be examined through the objective lens. The ophthalmologic apparatus according to any one of the above.   The optical axis for projecting the fixation target from the fixation target display means to the fixation target reflection means and the optical axis for guiding the measurement light to the reflection surface are parallel to each other. The ophthalmic apparatus according to 2.

Images