JP5772070B2 - Fundus photographing device - Google Patents

Description

  The present invention relates to a fundus imaging apparatus that images the fundus of a subject's eye.

Conventionally, a fundus imaging apparatus that images the fundus of a subject's eye includes a focusing lens for focusing on the fundus, and manually moves the focusing lens in the optical axis direction to manually perform focusing on the fundus. Such a fundus focus state is confirmed by a match state of an optically paired split index projected onto the fundus (see, for example, Patent Document 1).
Further, there is known a configuration in which a pseudo index is electronically displayed on a monitor based on a detection result of a split index projected on the fundus, thereby making it easier to confirm a focus state (for example, , See Patent Document 2).

JP 2002-125933 A International Publication No. 2009-093641

  However, when the focus state is manually adjusted using the optical or electronic split index displayed on the monitor, the match position of the split index is determined by the appearance of the examiner. There is a high possibility that an error due to.

  In view of the above-described problems of the conventional technology, it is an object of the present invention to provide a fundus imaging apparatus that can perform focusing with respect to the fundus more accurately in manual operation.

  In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) A fundus illumination optical system for illuminating the fundus of a subject's eye, a focus index projection optical system for projecting a focus index onto the fundus with light emitted from a light source, and movable in the optical axis direction A fundus imaging apparatus including a focusing lens and an imaging device capable of imaging the focus index projected onto the fundus, based on the focus index imaged by the imaging device Detection means for detecting a focus state of the fundus imaging optical system with respect to the eye to be examined, an electronic indicator generated based on a detection result of the detection means, and the focus index imaged by the imaging element. Control means for simultaneously displaying on a monitor, and the imaging device is further capable of capturing a fundus image including the focus index. There, the control means, the electronic indicators, characterized that you displayed superimposed on the fundus image including the focus index.

  According to the present invention, it is possible to provide a fundus photographing apparatus capable of performing focusing with respect to the fundus more accurately in manual operation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram of an external configuration of a fundus camera. The fundus camera includes a base 1, a movable base 2 that can move in the left-right direction (X direction) and front and rear (working distance, Z direction) with respect to the base 1, and an operation panel provided on the upper surface of the movable base 2. 2a, an imaging unit (apparatus body) 3 that is provided so as to be movable in a three-dimensional direction with respect to the moving table 2, and stores an optical system to be described later, (XYZ) direction drive unit 6, a face support unit 5 fixed to the base 1 for supporting the subject's face, and a display that can be tilted on the examiner side of the imaging unit 3 Part (monitor) 8. The monitor 8 displays an observation image of the anterior segment of the subject's eye and an observation (photographing) image of the fundus. In the present embodiment, an optical (or electronic) split index for indicating the focus state to the examiner and an indicator for guiding the split index to the coincidence state on the fundus image when the fundus is observed. It is displayed on the monitor 8 in a superimposed manner. A detailed description of the split indicator and indicator will be given later.

  Here, FIG. 2 shows an explanatory diagram of the configuration of the operation panel 2a. On the operation panel 2a, the joystick 4 for moving the moving base 2 on the base 1 in the XZ direction with respect to the subject eye E and the split index displayed on the monitor 8 can be manually operated. A focus knob 9 for adjustment, and various operation members such as an internal fixation target presentation switch 11 for changing a fixation target presentation pattern and a presentation position according to standard photographing or fundus peripheral photographing, etc. are provided. ing. Here, the focus knob 9 is provided to be rotatable in the right direction (arrow A direction) and the left direction (arrow B direction). Further, the rotation direction of the focus knob 9 is determined in accordance with the display direction of an indicator to be described later. When the examiner operates the focus knob 9 while checking the indicator, an optical device such as a focusing lens to be described later is operated. The member can be moved in the optical axis direction, and the split index indicating the focus state can be easily matched with high accuracy.

  Next, the configuration of the optical system and the control system provided inside the photographing unit 3 will be described. FIG. 3 is a schematic configuration diagram of an optical system and a control system of the fundus camera. The optical system includes an illumination optical system 10, a fundus observation / imaging optical system 30 for observing and photographing the fundus of the subject's eye, and a split index projection for projecting a split index (focus index) onto the fundus of the subject's eye. Optical system 40, alignment index projection optical system 50 that projects an alignment index light beam onto the anterior segment of the subject's eye, anterior segment observation optical system 60 that captures the anterior segment of the subject's eye, and the subject's eye It is comprised from the fixation target presentation optical system 70 for guide | inducing the eyes | visual_axis of this.

  <Illumination Optical System> The illumination optical system 10 includes an observation illumination optical system and a photographing illumination optical system. The observation illumination optical system is disposed between an infrared light source 11 that emits a near-infrared light beam, an infrared filter 12 that transmits near-infrared light, a condenser lens 13, and a condenser lens 13 and a ring slit 17. Dichroic mirror 16, ring slit 17 having a ring-shaped opening, relay lens 18, mirror 19, black spot plate 20 having a black spot at the center, relay lens 21, perforated mirror 22, dichroic mirror as an optical path branching member (wavelength selection) Mirror) 24 and objective lens 25. Thereby, the fundus of the subject's eye is illuminated by the infrared light flux from the infrared light source 11. On the other hand, the photographing illumination optical system includes a photographing light source 14 that emits visible light such as a flash lamp and an LED, a condenser lens 15, an optical system from the ring slit 17 to the perforated mirror 22, and an objective lens 25. The fundus of the subject's eye is illuminated by the visible light beam.

  The dichroic mirror 16 has a characteristic of reflecting infrared light and transmitting visible light. The dichroic mirror 24 has a wavelength characteristic that transmits a wavelength from an infrared light source of the observation illumination optical system and reflects infrared light from an alignment index projection optical system 50 described later. The dichroic mirror 24 is obliquely installed so that it can be inserted into and removed from the optical path by an insertion / removal mechanism 66 composed of a solenoid and a cam, and is obliquely installed in the optical path when observing the fundus using the observation illumination optical system. When the fundus is photographed by the illumination optical system, it is removed from the optical path.

  <Fundus Observation / Shooting Optical System> The fundus oculi observation / shooting optical system 30 includes a fundus oculi observation optical system and a fundus photographic optical system. The fundus oculi observation optical system includes an objective lens 25, a photographing aperture 31 located in the vicinity of the aperture of the perforated mirror 22, a focusing lens 32 movable in the optical axis direction, an imaging lens 33, and an insertion / removal mechanism 39 for photographing the fundus from the optical path. A flip-up mirror 34 that can be inserted and removed is provided. In addition, a dichroic mirror 37 having infrared light reflection / visible light transmission characteristics, a relay lens 36, and an observation two-dimensional image sensor 38 having sensitivity in the infrared region are disposed in the optical path in the reflection direction of the flip-up mirror 34. The fundus illuminated by the infrared light source 11 is photographed. On the other hand, the fundus photographing optical system shares the objective lens 25 and the optical system from the photographing aperture 31 to the imaging lens 33 with the fundus observation optical system. Further, the fundus photographing optical system includes a photographing two-dimensional imaging device 35 having sensitivity in the visible range, and photographs the fundus illuminated by the visible light source 14. The imaging aperture 31 is disposed at a position substantially conjugate with the pupil of the subject eye E with respect to the objective lens 25. The focusing lens 32 is moved in the optical axis direction by a drive mechanism 49 including a motor.

  With the illumination optical system and the fundus observation / photographing optical system configured as described above, the light beam emitted from the infrared light source 11 at the time of fundus observation reaches the perforated mirror 22 from the infrared filter 12 through the relay lens 21. . Then, the light reflected by the perforated mirror 22 is transmitted through the dichroic mirror 24 and once converged near the pupil of the eye E by the objective lens 25, and then diffused to illuminate the fundus of the eye E. To do. On the other hand, the reflected light from the fundus is obtained by the objective lens 25, the dichroic mirror 24, the aperture of the perforated mirror 22, the photographing aperture 31, the focusing lens 32, the imaging lens 33, the flip-up mirror 34, the dichroic mirror 37, and the relay lens 36. Then, an image is formed on the image sensor 38. At the time of photographing the fundus, the reflected light from the fundus illuminated by the visible light source 11 passes through the objective lens 25, the aperture of the perforated mirror 22, the photographing aperture 31, the focusing lens 32, and the imaging lens 33, and is two-dimensional. An image is formed on the image sensor 35.

  <Split index projection optical system> The split index projection optical system 40 includes an infrared light source 41, a slit index plate 42, two declination prisms 43 attached to the slit index plate 42, a projection lens 47, and an optical path of the illumination optical system 10. A spot mirror 44 is provided obliquely. The spot mirror 44 is fixed to the tip of the lever 45 and is normally provided obliquely to the optical axis, but is retracted out of the optical path by rotation of the rotary solenoid 46 during photographing. The spot mirror 44 is disposed at a position conjugate with the fundus of the subject eye E. The light source 41, the slit indicator plate 42, the deflection prism 43, the projection lens 47, the spot mirror 44 and the lever 45 are moved in the optical axis direction by the drive mechanism 49 in conjunction with the focusing lens 32.

  Further, the light flux of the slit index plate 42 of the split index projection optical system 40 is reflected by the spot mirror 44 via the deflection prism 43 and the projection lens 47, and then the relay lens 21, the perforated mirror 22, the dichroic mirror 24, The light is projected onto the fundus of the subject's eye E through the objective lens 25. When the fundus is not in focus, the index image of the slit index plate 42 is separated and projected when it is in focus (coincidence). Then, split index images (split index images S1 and S2 described later) projected onto the fundus of the subject's eye E are imaged together with the fundus by the fundus observation imaging element 38.

  <Alignment Index Projection Optical System> In the alignment index projection optical system 50, a plurality of infrared light sources are arranged on a concentric circle centered on the photographing optical axis L1, and left and right across a vertical plane passing through the photographing optical axis L1. A first index projection optical system (0 degrees and 180) having an infrared light source 51 and a collimating lens 52 disposed symmetrically, and a plurality of infrared light sources disposed at different positions from the first index projection optical system And a second index projection optical system having 53. In this case, the first index projection optical system projects an infinite distance index on the cornea of the subject's eye E from the left and right directions, and the second index projection optical system moves the finite distance index on the cornea of the subject's eye E up and down. Project from a diagonal direction.

  <Anterior Eye Observation Optical System> The anterior eye observation optical system 60 is disposed on the reflection side of the dichroic mirror 24, and has an anterior eye portion and an alignment index illuminated by the anterior eye illumination light source 58 by the two-dimensional imaging device 65. Imaged. A pupil shape of the subject's eye is obtained from the anterior segment image captured by the two-dimensional imaging element 65. Further, the corneal reflected light by the alignment light beam is detected by the two-dimensional imaging element 65 by turning on the light source of the alignment index projection optical system 50. When the output of the two-dimensional image sensor 65 is input to the control unit 80, the anterior segment image AE is displayed on the monitor 8 (see FIG. 4). The anterior ocular segment observation optical system 60 also serves to detect the alignment state of the apparatus main body with respect to the subject's eye.

  <Fixation Target Presenting Optical System> The fixation target presenting optical system 70 includes a red visible light source (not shown) and a light-shielding plate in which a plurality of openings are formed. And the fixation target is located at different positions with respect to the optical axis L2 by selectively disposing the light-shielding plate opening of the fixation target switching member in front of the visible light source. Presented. Thereby, the presenting position of the fixation target is changed between standard photographing for photographing the fundus central part and peripheral photographing for photographing the fundus peripheral part.

  <Control System> The control unit 80 includes two-dimensional imaging elements 35, 38, 65, a joystick 4, a drive unit 6, a monitor 8, a focus knob 9, an insertion / removal mechanism 39, a drive mechanism 49, an insertion / removal mechanism 66, and storage means. The memory 85, each light source, etc. are connected. The memory 85 stores in advance various information (focus information) necessary for focus adjustment using the indicator. As the focus information, for example, position information on the image sensor 38 (hereinafter referred to as a reference position) that the split index is matched, the split index separation amount and the drive amount of the drive mechanism 49 (the position of the focusing lens 32). ), Information for determining the relationship between the split index separation amount and the indicator display state (or information for determining the relationship between the drive amount of the drive mechanism 49 and the indicator display state), etc. Is remembered. Note that the reference position at which the split index is matched is, for example, each optical system whose design information is known when the photographing optical system is properly aligned and focused with respect to the normal eye. The position on the image sensor 38 that is considered to match the pair of split indexes in consideration may be stored as the reference position.

  In addition, the control unit 80 performs control to display an anterior ocular segment image or fundus observation image (photographed image) on the monitor 8 in accordance with input signals from the two-dimensional imaging elements 35, 38, and 65, and performs various detection processes. For example, the control unit 80 detects the alignment index from the anterior segment image captured by the two-dimensional image sensor 65 and detects the pupil shape (note that the center position (pupil center) is obtained from the pupil shape). May be). Further, the control unit 80 detects the alignment deviation amount of the apparatus main body 3 with respect to the subject's eye based on the imaging signal of the imaging element 65. Further, the control unit 80 electronically forms and displays the reticle LT on the screen of the monitor 8 (see FIG. 4) on which the anterior segment image AE of the subject's eye E is displayed, and is detected. An alignment index A1 whose display position is moved in accordance with the amount of alignment deviation is electronically formed and combined and displayed.

  In addition, the control unit 80 displays the split index image and the fundus image captured by the two-dimensional image sensor 38 on the monitor 8 and controls the display of an electronic indicator generated based on the match condition (separation state) of the split index. I do. Further, based on the focus information stored in the memory 85, the control unit 80 drives the drive mechanism 49 based on the split index image separation amount obtained by the image sensor 38 based on the focus information, and the split index matches. Thus, the focusing lens 32 and the spot mirror 44 (including the lever 45) are controlled to move integrally on the optical axis. Then, an indicator state corresponding to the separation amount of the split indicator is displayed on the monitor 8. On the other hand, in the case of manual operation (manual operation), the driving mechanism 49 is driven by the rotation operation of the focus knob 9, whereby the focusing lens 32 and the spot mirror 44 are moved on the optical axis. As a result, the display position (separation state) of the split index displayed on the monitor 8 changes. Therefore, the control unit 80 detects the split amount of the split index image detected by the image sensor 38 at any time, so that the separation amount. Control for displaying the indicator state on the monitor 8 is repeatedly performed. It is not necessary for such control to detect both of a pair of separated split indicators. If the separation position of at least one of the split indicators is detected by the image sensor 38, a predetermined reference is obtained. The relationship with the position (focus state) can be grasped.

  Next, an operation of the fundus camera having the above configuration will be described. Here, a case where a manual focus mode in which the examiner performs manual focusing is set will be described as an example. Here, it is assumed that auto-alignment is set and the fixation target presentation position is set so that the center position (rear pole part) of the fundus is photographed.

  For example, when autofocus cannot be performed, such as when the subject's eyes are cloudy due to cataracts or the like, focus adjustment is performed manually. However, in the conventional focus adjustment by manual operation, it is determined by observation of the examiner whether or not the pair of split indexes match. However, there is a high possibility that the judgment of the degree of overlap (the degree of match) of the split indices varies depending on the examiner. Therefore, in the present embodiment, an indicator that objectively indicates the match status of the split index is used so that it can be uniquely determined whether or not the split index is matched. In this way, focus adjustment can be performed with high accuracy regardless of individual differences.

  First, in a state where the face of the subject is supported by the face support unit 5, the movable table 2 is moved so that the photographing unit 3 approaches the subject's eye E by operating the joystick 4. Then, the fixation target presenting optical system 70 is turned on to fix the eye of the subject. Further, the examiner moves the photographing unit 3 in the three-dimensional direction so that the anterior segment image AE is displayed on the monitor 8 by operating the joystick 4. When the anterior segment image AE appears on the monitor 8, the alignment index image is also displayed on the monitor 8.

  Here, FIG. 4 shows an example of the anterior segment image AE displayed on the monitor 8. FIG. 4A shows a state where alignment is not correct, and FIG. 4B shows a state where alignment is correct. When the alignment index image projected onto the cornea of the subject's eye is detected by the image sensor 65, the control unit 80 detects the alignment deviation of the imaging unit 3 with respect to the subject's eye based on the imaging signal from the image sensor 65. Detect the unit quantity. Specifically, the control unit 80 detects the XY coordinates of the center of the ring shape formed by the index images Ma to Mh projected in a ring shape as a substantially corneal apex (alignment reference position), and displays the alignment index A1. In addition, the reticle LT is displayed at a reference position in the XY direction that is set in advance on the image sensor 65 (for example, the intersection of the imaging surface of the image sensor 65 and the photographing optical axis L1), and the alignment index A1. The amount of deviation from the reticle LT is obtained. Then, the alignment deviation amount in the Z direction is obtained by comparing the distance between the index images Ma and Me at infinity and the distance between the index images Mh and Mf at finite distance.

  In the present embodiment, the control unit 80 moves the photographing unit 3 so that the alignment deviation amount in the three-dimensional direction satisfies a predetermined alignment allowable range so that the reticle LT matches the alignment index A1, and the three-dimensional direction Alignment alignment state is determined. The alignment in the differential distance direction can be confirmed by increasing or decreasing the number of indicators G displayed on the monitor 8. Then, as shown in FIG. 4B, the examiner performs alignment in the working distance direction by operating the joystick 4 so that the number of the indicators G becomes one.

  When the alignment state is completed as described above, the control unit 80 performs focus adjustment on the fundus. Here, FIG. 5 shows an example of a fundus image F displayed on the monitor 8. FIG. 5A shows a state where the focus is not matched, and FIG. 5B shows a state where the focus is matched. In order to facilitate understanding, a display position on the monitor 8 corresponding to a reference position set at a predetermined position on the image sensor is formed as a reference position D for convenience.

  As shown in FIG. 5, when the fundus image F captured by the image sensor 38 and the split indices S1 and S2 are displayed on the monitor 8, the control unit 80 causes the split indices S1 and S1 with respect to the reference position D described above. A deviation amount (or separation amount) from the reference position D of S2 is obtained (detected) from a signal from the image sensor 38. In this embodiment, the split indicators S1 and S2 are moved (separated) in the left-right direction on the screen of the monitor 8. Further, the control unit 80 displays the split position S1 and S2 in the moving direction (for example, each split index S1 and S2 is displayed on the left or right with respect to the set reference position D). Whether the focusing lens 32 is in the plus direction or the minus direction with respect to the focus coincidence position.

  For example, as shown in FIG. 5A, when the split index S1 is displayed on the left side of the paper with respect to the reference position D (the split index S2 is on the right side), the focusing lens 32 is more positive than the proper focus position. Suppose you are on the side. On the other hand, when the split target S1 is displayed on the right side (the split index S2 is on the left side) with respect to the reference position D, it is assumed that the focusing lens 32 is on the minus side with respect to the proper focus position.

  Next, the control unit 80 controls the electronic indicators I (I1, I2) to be displayed on the monitor 8. The indicator I includes a combination of an indicator I1 indicating that the focus is achieved, and an indicator I2 that quantitatively indicates a focus shift amount and a shift direction. In the present embodiment, display control is performed to increase or decrease the display number of the indicator I2 in the left-right direction with the indicator I1 as the center, according to the focus shift amount and the shift direction. In the present embodiment, a vertically long rectangular indicator I1 is formed on the projected line 45a of the lever 45 on the line (vertical line) when the split index matches.

  Here, an enlarged view of the indicator I is shown in FIG. For example, in a state where the focus is not appropriate and the focusing lens 32 is on the plus side, one or more in the right direction depending on the amount of split index deviation from the reference position D (split index separation amount). The book indicator I2 is displayed. On the other hand, when the focusing lens 32 is on the minus side, one or more indicators I2 are displayed in the left direction in accordance with the amount of shift of the split index from the reference position D. As a result, the examiner can quantitatively confirm the separation state of the split indicator using the indicator.

  In the present embodiment, the number of indicators I2 displayed when the split indicators S1 and S2 are in the separated state is the distance from the reference position D to the display position of the split indicators S1 and S2 (the deviation of the indicator with respect to the reference position D). The amount is determined according to the amount. That is, display control is performed to increase the number of indicators I2 as the split index S1 (S2) is moved away from the reference position D. Here, it is assumed that the maximum number of indicators I2 displayed is four.

  Note that such a method of calculating the split index separation amount may be used depending on the detection status of the split indices S1 and S2. For example, when two split indicators S1 and S2 are detected by the image sensor 38, the separation amount is calculated based on the distance between the centers of the two split indicators. On the other hand, when only one of the split indices S1 and S2 is detected, as described above, the separation amount is obtained according to the distance from the reference position D to the display position of the detected split index. Anyway.

The examiner turns the focus knob 9 so that the display of the indicator I2 disappears (so that only the indicator I1 is displayed) in correspondence with the display direction of the indicator I2 with respect to the indicator I1 while watching the indicator displayed on the monitor 8. Let In the present embodiment, when the focus knob 9 is rotated clockwise (in the direction of arrow A shown in FIG. 2), the focusing lens 32 is moved to the plus side, and the spot mirror 44 is integrated with the focusing lens 32 accordingly. Move in the direction of the optical axis. When the focus knob 9 is rotated counterclockwise (arrow B direction), the focusing lens 32 is moved to the minus side, and the spot mirror 44 is moved integrally with the focusing lens 32 in the optical axis direction accordingly.
By using such an indicator, the focus state can be objectively determined, and a suitable focus state can be obtained regardless of the examiner.

  Note that if the display state (shape, color, etc.) of the indicator I1 displayed when the split indicators S1 and S2 match and the display state of the indicator I2 displayed when they do not match are changed for the examiner. The match state is more visually understandable. For example, by changing the size and color of the indicator I2 with respect to the indicator I1, it is possible to make the indicator determination easier.

  In this embodiment, the example in which the split indicators S1 and S2 are moved in the horizontal direction on the screen of the monitor 8 has been described. However, the present invention is not limited to this. It is more preferable if control is performed. For example, when the split state of the split indicators S1 and S2 is moved in the vertical direction on the screen of the monitor 8, the indicator I1 described above is rotated by 90 ° to display a horizontally long indicator, and the indicator I2 is displayed. In accordance with this, it is made to increase or decrease on the monitor 8 in the vertical direction.

  Further, in a state where infrared light is illuminated for fundus observation, it may be difficult to detect the split index with the image sensor. In such a case, when the anterior ocular segment observation image is displayed on the monitor 8 for anterior ocular segment observation, the fundus illumination by the fundus illumination optical system is turned off from the beginning (or the split index image). If the split index is projected onto the fundus (with the fundus illuminated to such an extent that it can be detected), and the separation amount of the split index image (the amount of deviation from the reference position) is detected in advance by the image sensor 38 when observing the anterior segment. Good. Such detection is preferably performed at the timing when the alignment in the anterior segment is completed and the observation image displayed on the monitor 8 moves from the anterior segment to the fundus.

  The control unit 80 may display an indicator on the fundus observation screen displayed after switching to the fundus observation screen based on the split index separation amount (detection result) detected during the anterior segment observation. At the same time, the detection result and the amount of movement of the focusing lens 32 necessary for focusing are associated in advance, and the display of the indicator is appropriately changed based on the movement of the focusing lens (the amount of driving of the driving mechanism 49) during fundus observation. Good. By performing such control, even when the fundus is bright due to the illumination light for observation and it is difficult to detect the split index, it is possible to perform focusing appropriately by manual operation.

  In addition, although the example which performs focus adjustment by the manual operation by the examiner has been described above, for example, even when focus adjustment is performed by autofocus, an optical split index or the like displayed on the monitor 8 It may be difficult to confirm the display state of. Also in this case, the indicator as described above is displayed, so that the examiner can easily confirm the match state of the split index.

  In this embodiment, an example in which the indicator is displayed on the fundus of the monitor is shown, but the present invention is not limited to this. An indicator may be displayed around the fundus displayed on the monitor 8 (without overlapping the fundus image). In this case as well, by adjusting the increase / decrease direction of the indicator and the operation direction of the focus knob, the examiner can easily adjust the focus using the indicator.

It is explanatory drawing of the external appearance structure of a fundus camera. It is explanatory drawing of a structure of an operation panel. It is a schematic block diagram of the optical system and control system of a fundus camera. It is an example of the anterior segment image displayed on a monitor. It is an example of the fundus oculi displayed on the monitor. It is an enlarged view of an indicator.

DESCRIPTION OF SYMBOLS 8 Monitor 9 Focus knob 10 Illumination optical system 11 Infrared light source 30 Fundus observation and imaging optical system 35, 38, 65 Two-dimensional image sensor 40 Split index projection optical system 41 Light source 49 Drive mechanism 58 Anterior ocular segment illumination light source 60 Anterior segment Observation optical system 80 Control unit 85 Memory

Claims (5)

A fundus illumination optical system for illuminating the fundus of the subject's eye;
A focus index projection optical system for projecting a focus index on the fundus with light emitted from a light source;
A fundus imaging optical system comprising a focusing lens movable in the optical axis direction, and an imaging device capable of imaging the focus index projected onto the fundus;
A fundus imaging apparatus comprising:
Detecting means for detecting a focus state of the fundus imaging optical system with respect to an eye based on the focus index imaged by the image sensor;
A control means for simultaneously displaying an electronic indicator generated based on a detection result of the detection means and the focus index imaged by the imaging device on a monitor ;
The imaging device can further capture a fundus image including the focus index,
Wherein, the fundus photographing apparatus the electronic indicators, characterized that you displayed superimposed on the fundus image including the focus index. The fundus imaging apparatus according to claim 1,
The control means, based on said detection result by the detection means, in a state where no in-focus state and focus, the fundus photographing apparatus according to claim Rukoto switching a display state of the indicator. The fundus imaging apparatus according to claim 1 or 2,
The control means, based on said detection result by the detection means, in a state where no in-focus state and focus, the fundus photographing apparatus according to claim Rukoto change the color of at least a part of symbols forming the indicator . The fundus imaging apparatus according to any one of claims 1 to 3,
Drive means for driving the focusing lens;
The fundus imaging apparatus , wherein the control unit controls driving of the driving unit based on a detection result of the detection unit and performs autofocus on the fundus. The fundus imaging apparatus according to any one of claims 1 to 4,
The focus index is a pair of optical split indices in which the matching state on the fundus is adjusted by moving the focusing lens,
Storing means for storing, as a reference position, a position on the image sensor that the pair of split indexes are matched,
The fundus imaging apparatus according to claim 1, wherein the detection unit detects the coincidence state by comparing a position on the imaging element where at least one split index of the split index is imaged with the reference position .