JP2010035727A - Fundus camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fundus camera capable of fine-tuning a photographing position appropriately. <P>SOLUTION: In the fundus camera including a manual movement mechanism part for relatively moving the photographing part with respect to a subject's eye, a sensor for detecting the driving of the manual movement mechanism part, an automatic movement mechanism part for relatively moving the photographing part with respect to the subject's eye, and a movement control part which detects a misalignment of the photographing part with the subject's eye and outputs a driving signal to the automatic movement mechanism part from the detection result, the movement control part drives the automatic movement mechanism to bring the misalignment within an accepted range when the driving of the manual movement mechanism part is not detected by the sensor, and does not drive the automatic movement mechanism part when the driving of the manual movement mechanism part is detected by the sensor in a case that the detected misalignment is out of the accepted range of the prescribed alignment and is within a range in which the prescribed alignment can be performed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fundus camera that photographs the fundus of a subject's eye.

  Conventional fundus cameras generally perform fine adjustment of the shooting position by moving the shooting part using a joystick while referring to corneal bright spots (so-called working dots) that can be observed together with the fundus observation image. is there.

Such an apparatus includes an alignment detection system that detects a relative position between the subject's eye and the imaging unit, and a drive mechanism that moves the imaging unit by electric drive, and is based on a detection result from the alignment detection system. It is known that an alignment error is detected and automatic alignment is activated when the alignment error exceeds a predetermined allowable alignment range (see Patent Document 1). In this case, the imaging position can be finely adjusted by the examiner by setting the alignment allowable range wider. The fundus camera that performs such automatic alignment control is convenient for the examiner because the photographing position is automatically corrected when the subject's eye moves greatly and the working dot disappears.
JP 2005-160550 A

  By the way, when performing the above automatic alignment, depending on the subject's eye, there may be a good imaging position at an imaging position exceeding the alignment allowable range. For example, if the subject's eye is a cataract eye, when the examiner adjusts the shooting position to avoid flare and illumination unevenness due to opacity of the crystalline lens, the alignment error exceeds the allowable range and automatic alignment is activated. Therefore, there are cases where alignment cannot be performed to a good photographing position.

  In such a case, conventionally, after the automatic alignment control is stopped by a predetermined mode change switch arranged in the switch unit, the photographing position is adjusted again.

  In view of the above problems, an object of the present invention is to provide a fundus camera that can suitably perform fine adjustment of a photographing position.

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

(1)
An imaging unit in which an imaging optical system that images the fundus of the subject and an observation optical system that has an image sensor and observes the fundus;
A manual movement mechanism that has an operation member and moves the imaging unit relative to the eye of the subject by operating the operation member;
A sensor for detecting the driving of the manual movement mechanism,
An automatic movement mechanism having an electric motor for moving the imaging unit relative to the eye of the subject;
A monitor,
A display control unit for processing an output signal from the image sensor and displaying an observation image of the fundus on the monitor;
An alignment detection optical system having a light receiving element for detecting misalignment of the imaging unit with respect to the eye of the subject;
A movement control unit that detects an alignment shift of the imaging unit with respect to the subject's eye based on a light reception signal output from the light receiving element, and outputs a drive signal to the automatic movement mechanism unit based on the detection result;
In a fundus camera having
In the case where the detected misalignment is within a predetermined alignment allowable range outside the predetermined alignment allowable range, the movement control unit,
When the drive of the manual movement mechanism unit is not detected by the sensor, the automatic movement mechanism unit is driven so that the misalignment falls within an allowable range,
When the driving of the manual movement mechanism is detected by the sensor, the automatic movement mechanism is not driven.
(2) In the fundus camera of (1),
The light receiving element of the alignment detection optical system is a two-dimensional light receiving element capable of acquiring an anterior segment image of the subject's eye,
The alignable range is set to be wider than that in the case where the misalignment is detected by capturing an image of the fundus.
(3) In the fundus camera of (2),
The sensor detects a change amount of a relative position between the subject eye and the imaging unit per predetermined time based on a light reception signal from the light receiving element, and when the detected change amount is less than a predetermined change amount The driving of the manual movement mechanism is detected.
(4) In the fundus camera of (2),
The manual movement mechanism has an operation detection unit that detects that the operation member is operating by a manual operation of an examiner, and the sensor is operated based on a detection signal output from the operation detection unit. When it is detected that it is in operation, the driving of the manual movement mechanism is detected.
(5) In the fundus camera of (1),
The movement control unit includes a deviation direction storage unit that stores a direction of the alignment deviation when the detected alignment deviation is outside a predetermined alignment allowable range so that the alignment deviation falls within the predetermined alignment allowable range. After driving the automatic movement control unit,
In the misalignment direction stored by the misalignment direction storage unit, the automatic movement mechanism is not driven when the misalignment again falls outside a predetermined alignment allowable range.

  According to the present invention, fine adjustment of the photographing position can be suitably performed.

  Embodiments according to the present invention will be described below with reference to the drawings. FIG. 1 is an external configuration diagram of a fundus camera according to the present embodiment.

The fundus camera includes a base 1, a movable base 2 that can move in the left and right direction (X direction) and the front and rear (working distance) direction (Z direction) with respect to the base 1, and a three-dimensional direction with respect to the movable base 2. And a face support unit 5 fixed to the base 1 in order to support the face of the subject.
Further, the present apparatus is provided with an automatic movement mechanism that has an electric motor and moves the imaging unit 3 relative to the subject's eye. More specifically, the imaging unit 3 is moved in the left-right direction, the up-down direction (Y direction), and the front-rear direction with respect to the subject's eye E by an electrically driven XYZ drive unit 6 provided on the moving table 2. The

  In addition, the apparatus is provided with a manual movement mechanism that moves the imaging unit 3 relative to the eye of the subject by operating the operation member (joystick 4). More specifically, a sliding mechanism (not shown) that slides the movable table 2 in the XZ direction on the base 1 is provided. When the joystick 4 is operated, the movable table 2 moves on the base 1 in the XZ direction. Is slid in the direction. Further, by rotating the rotary knob 4a, the XYZ drive unit 6 is driven in the Y direction and the photographing unit 3 is moved in the Y direction. Note that a monitor 8 that displays a fundus observation image, a fundus image, an anterior eye observation image, and the like is provided on the examiner side of the imaging unit 3.

  FIG. 2 is a schematic configuration diagram of an optical system and a control system housed in the photographing unit 3. The imaging unit 3 includes an imaging optical system for imaging the fundus of the subject's eye and an observation optical system that has an image sensor and observes the fundus. In FIG. 2, the optical system includes an illumination optical system 10, a fundus observation / imaging optical system 30 that captures a fundus image of a subject's eye, an alignment index projection optical system 50, an anterior segment observation optical system 60, and a fixation. The sign presentation optical system 70 is roughly divided.

  <Illumination Optical System> The illumination optical system 10 includes an observation illumination optical system and a photographing illumination optical system. The photographing illumination optical system includes a photographing light source 14 such as a flash lamp, a condenser lens 15, a ring slit 17, a relay lens 18, a mirror 19, a black spot plate 20 having a black spot at the center, a relay lens 21, a perforated mirror 22, and an objective lens. 25.

  The observation illumination optical system includes a light source 11 such as a halogen lamp, an infrared filter 12 that transmits near-infrared light having a wavelength of 750 nm or more, a condenser lens 13, and a dichroic disposed between the condenser lens 13 and the ring slit 17. An optical system from the mirror 16 and the ring slit 17 to the objective lens 25 is provided. The dichroic mirror 16 has a characteristic of reflecting light from the infrared light source 11 and transmitting light from the imaging light source 14.

  <Fundus observation / fundus imaging optical system> The fundus observation / imaging optical system 30 includes an objective lens 25, a photographing diaphragm 31 located near the aperture of the perforated mirror 22, a focusing lens 32 movable in the optical axis direction, and an imaging lens. 33. At the time of fundus photography, a flip-up mirror 34 that can be inserted and removed from the optical path by the insertion / removal mechanism 39 is provided, and the photographing optical system and the fundus observation optical system share the objective lens 25 and the optical system from the photographing aperture 31 to the imaging lens 33. To do. The photographing 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 moving mechanism 49 including a motor. Reference numeral 35 denotes a photographing two-dimensional image sensor having sensitivity in the visible range. In the optical path in the reflection direction of the flip-up mirror 34, a dichroic mirror 37 having infrared light reflection and visible light transmission characteristics, a relay lens 36, and an observation two-dimensional imaging device 38 having sensitivity in the infrared region are arranged. .

  A dichroic mirror (wavelength selective mirror) 24 that can be inserted and removed as an optical path branching member is provided obliquely between the objective lens 25 and the perforated mirror 22. The dichroic mirror 24 reflects the wavelength light (center wavelength 940 nm) of the alignment index projection optical system 50 and the anterior segment illumination light source 58, and includes a light source wavelength (center wavelength 880 nm) of the wavelength light of the fundus observation illumination. It has a characteristic of transmitting through. At the time of shooting, the dichroic mirror 24 is flipped up by the insertion / removal mechanism 66 and retracts out of the optical path. The insertion / removal mechanism 66 can be composed of a solenoid and a cam.

  The light beam emitted from the observation light source 11 is converted into an infrared light beam by the infrared filter 12 and reflected by the condenser lens 13 and the dichroic mirror 16 to illuminate the ring slit 17. The light transmitted through the ring slit 17 reaches the perforated mirror 22 through the relay lens 18, the mirror 19, the black spot plate 20, and the relay lens 21. The light reflected by the perforated mirror 22 is transmitted through the dichroic mirror 24, and once converged in the vicinity of the pupil of the eye E by the objective lens 25, then diffuses and illuminates the eye fundus of the subject.

  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. The output of the image sensor 38 is input to the controller 80, and the fundus observation image of the eye of the subject imaged by the image sensor 38 is displayed on the monitor 8 as shown in FIG.

  The luminous flux emitted from the imaging light source 14 passes through the dichroic mirror 16 via the condenser lens 15 and then passes through the same optical path as the illumination light for fundus observation, and the fundus is illuminated with visible light. Then, the reflected light from the fundus is imaged on the two-dimensional image sensor 35 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.

  <Alignment Index Projection Optical System> The alignment index projection optical system 50 that projects the alignment index beam is 45 degrees concentrically about the photographic optical axis L1 as shown in the diagram within the dotted line A in the upper left of FIG. A plurality of infrared light sources are arranged at intervals, and a first index projection optical system (0) having an infrared light source 51 and a collimating lens 52 arranged symmetrically with respect to a vertical plane passing through the photographing optical axis L1. And a second index projection optical system having six infrared light sources 53 arranged at positions different from the first index projection optical system. 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. Projection is performed from a direction or an oblique direction. In FIG. 2, for convenience, the first index projection optical system (0 degrees and 180 degrees) and only a part of the second index projection optical system (45 degrees and 135 degrees) are shown. .

  <Anterior Eye Observation Optical System> An anterior eye observation (imaging) optical system 60 that images the anterior eye part of a subject's eye is provided with a field lens 61, a mirror 62, a diaphragm 63, and a relay on the reflection side of the dichroic mirror 24. A lens 64 and a two-dimensional imaging element (light receiving element) 65 having infrared sensitivity are provided. The two-dimensional imaging element 65 also serves as an imaging means for detecting an alignment index, and the anterior segment illuminated by the anterior segment illumination light source 58 that emits infrared light having a center wavelength of 940 nm and the alignment index are imaged. The anterior segment illuminated by the anterior segment illumination light source 58 is received by the two-dimensional imaging element 65 from the objective lens 25, the dichroic mirror 24, and the field lens 61 via the relay lens 64 optical system. In addition, the alignment light beam emitted from the light source of the alignment index projection optical system 50 is projected onto the subject's eye cornea, and the cornea reflection image is received by the two-dimensional image sensor 65 via the objective lens 25 to the relay lens 64 ( Projected). The output of the two-dimensional image sensor 65 is input to the control unit 80, and the anterior segment image captured by the two-dimensional image sensor 65 is displayed on the monitor 8 as shown in FIG. The anterior ocular segment observation optical system 60 also serves as an alignment detection optical system having a light receiving element (two-dimensional imaging element 65) for detecting an alignment shift of the imaging unit 3 with respect to the subject's eye.

  <Fixed Target Presenting Optical System> A fixed target presenting optical system 70 for presenting a fixed target for fixing a subject's eye includes a red light source 74, a light shielding plate 71 in which an aperture is formed, and a relay lens. 75, and shares the optical path of the observation optical system 30 from the flip-up mirror 34 to the objective lens 25 via the dichroic mirror 37. Note that the fixation target presenting optical system 70 has a configuration (not shown) in which the fixation position of the fixation target is variable (not shown), and can guide the subject's eye in a predetermined line-of-sight direction (for example, JP, A 2005-95450 publication). Therefore, it is possible to perform peripheral shooting.

  In this case, the light shielding plate 71 is illuminated from behind by the light source 74 to become a fixation target (fixation lamp). The luminous flux from the fixation target passes through the relay lens 75, the dichroic mirror 37, the flip-up mirror 34, the imaging lens 33, the focusing lens 32, the perforated mirror 22, the dichroic mirror 24, and the objective lens 25 to be examined. The light is condensed on the fundus of the human eye, and the subject visually recognizes the light flux from the opening hole 71 as a fixation target.

  <Control System> The two-dimensional imaging elements 65, 38, and 35 are connected to the control unit 80. The control unit 80 detects an alignment index from the anterior segment image captured by the two-dimensional image sensor 65. The control unit 80 is connected to the monitor 8 and controls the display image (for example, the output signal from the image sensor 38 is processed to display the fundus observation image on the monitor 8). In addition, the control unit 80 includes an XYZ driving unit 6, a moving mechanism 49, an insertion / removal mechanism 39, a rotary knob 4a, a photographing switch 4b, a switch unit 84 having various switches, a memory 85 as a storage unit, A light source or the like is connected.

  Here, the control unit 80 detects the misalignment of the imaging unit 3 with respect to the subject's eye based on the light reception signal output from the imaging element (light receiving element) 65, and the XYZ driving unit 6 determines based on the detection result. A drive signal is output. Further, in this embodiment, since a two-dimensional light receiving element (imaging element 65) that can acquire an anterior segment image of the subject's eye is used, the alignment possible range is a misalignment caused by imaging a fundus image. It is set wider than the case of detecting.

  Further, as shown in the anterior ocular segment image observation screen of FIG. 3 and the fundus oculi observation screen of FIG. 8, the control unit 80 electronically places a reticle (alignment mark) LT serving as an alignment reference at a predetermined position on the screen of the display monitor 8. The alignment index A1 is electronically displayed on the screen of the display monitor 8 so that the relative distance between the alignment index A1 and the reticle LT is changed based on the detected misalignment in the XY directions. Form and display. In addition, the control unit 80 displays an indicator G that indicates the misalignment in the Z direction, and increases or decreases the number of the indicators G based on the detected misalignment in the Z direction.

  The operation of the fundus camera having the above configuration will be described. First, the face of the subject is supported by the face support unit 5. At the initial stage, the dichroic mirror 24 is inserted in the optical path of the photographing optical system 30, and the anterior segment image captured by the two-dimensional image sensor 65 is displayed on the monitor 8. The examiner moves the imaging unit 3 left and right and up and down by operating the joystick 4 so that the anterior segment image appears on the monitor 8. When the anterior segment image appears on the monitor 8, as shown in FIG. 3, eight index images Ma to Mh appear.

  As described above, when the alignment index image projected on the subject's eye cornea is detected by the two-dimensional image sensor 65, the control unit 80 starts automatic alignment control. The control unit 80 detects the alignment deviation amount Δd of the apparatus main body 3 with respect to the subject's eye based on the imaging signal from the two-dimensional imaging element 65. More specifically, the XY coordinate of the center of the ring shape formed by the index images Ma to Mh projected in a ring shape is detected as the substantially corneal apex position Mo, and is set in the XY direction set on the image sensor 65 in advance. A deviation amount Δd between the alignment reference position O1 (for example, the intersection of the imaging surface of the imaging element 65 and the photographing optical axis L1) and the corneal apex position coordinates is obtained (see FIG. 4).

  Then, the control unit 80 operates automatic alignment by drive control of the XYZ drive unit 6 so that the deviation amount Δd falls within the allowable range A for completion of alignment. Whether or not the alignment amount in the XY direction is appropriate is determined depending on whether or not the deviation amount Δd falls within the allowable range A for completion of alignment and the time continues for a certain time (for example, 10 frames of image processing or 0.3 second). .

  Further, the control unit 80 obtains the alignment deviation amount in the Z direction by comparing the interval between the index images Ma and Me at infinity detected as described above and the interval between the index images Mh and Mf at finite distance. . In this case, when the apparatus main body 3 is displaced in the working distance direction, the control unit 80 changes the image interval between the index images Mh and Mf while the interval between the infinity indexes Ma and Me hardly changes. The amount of alignment deviation in the working distance direction with respect to the subject's eye is obtained using the characteristic of performing (refer to Japanese Patent Laid-Open No. 6-46999 for details).

  Similarly, in the Z direction, the control unit 80 obtains a deviation amount with respect to the alignment reference position O1 (z) in the Z direction so that the deviation amount falls within the alignment allowable range A in which the alignment is completed. In addition, automatic alignment by drive control of the XYZ drive unit 6 is activated. The control unit 80 determines whether or not the alignment in the Z direction is appropriate depending on whether or not the amount of deviation in the Z direction is within an allowable range for completion of alignment for a certain period of time.

When the alignment operation in the XYZ directions satisfies the alignment completion condition by the alignment operation described above, the control unit 80 determines that the alignment in the XYZ directions is matched, and stops the operation of the driving unit 6.
If it is determined that the predetermined alignment condition is satisfied, the control unit 80 switches the display image on the monitor 8 from the anterior ocular segment image to the fundus oculi observation image (see FIG. 8). When the observation screen switching signal is issued in this way, the control unit 80 switches the alignment allowable range for operating the automatic alignment from the allowable range A to the allowable range C, and whether the alignment deviation amount is within the allowable range C. To determine whether automatic alignment is possible. The allowable range C is set wider than the allowable range A. The permissible range C is an imaging position when the examiner can finely adjust the imaging position and when the subject's eye moves greatly or when the alignment deviation becomes too large and fine adjustment becomes difficult. Is set so that it can be corrected. For example, the allowable range C is set to a region having a radius of 1.5 mm with the alignment reference position O1 as the center.

  When the allowable range is set wide as described above, the examiner performs fine adjustment of the photographing position by manual operation of the joystick 4 while viewing the fundus image displayed on the monitor 8. The examiner adjusts the focus of the fundus using a focus adjustment switch provided in the switch unit 84 (auto focus control may be used).

  Here, when the detected alignment deviation amount Δd exceeds the allowable range C, the control unit 80 controls the driving unit 6 so that the deviation amount Δd falls within the allowable range C (automatic alignment).

  Further, the control unit 80 detects the amount of change in the relative position between the subject's eye and the imaging unit per predetermined time based on the light reception signal from the image sensor 65, and the detected change amount is set to the predetermined change amount. When it falls below, the drive of a manual movement mechanism part is detected (refer FIG. 5, FIG. 6). That is, the anterior ocular segment observation optical system 60 and the control unit 80 also serve as sensors that detect the driving of the manual movement mechanism unit.

  Then, when the detected misalignment (deviation amount Δd) is outside the predetermined alignment allowable range C and within the predetermined alignment possible range, the control unit 80 detects the driving of the manual movement mechanism unit by the aforementioned sensor. If not, the XYZ drive unit 6 is driven so that the misalignment falls within the permissible range C, and when the drive of the manual movement mechanism unit is detected by the aforementioned sensor, the XYZ drive unit 6 is not driven (FIG. 7). (Refer to the flowchart).

  More specifically, the control unit 80 monitors the amount of change H (Hxy, Hz) in the relative positions of the subject eye, the imaging unit 3 and the relative position per predetermined time, and the amount of change H (Hxy, Hz) is predetermined. It is determined whether or not the manual movement mechanism is driven based on whether or not the amount of change HS (HSxy, HSz) exceeds the predetermined amount of change HS (HSxy, HSz). When the amount of change HS (HSxy, HSz) is exceeded, the XYZ drive unit 6 is driven. The XYZ driving unit 6 is not driven when it falls below the predetermined change amount HS (HSxy, HSz).

  In addition, when calculating | requiring the variation | change_quantity Hxy regarding XY direction, the control part 80 acquires the anterior eye part image as a reference | standard image for calculating | requiring the variation | change_quantity Hxy based on the imaging signal from the image pick-up element 65, for example, and a reference | standard image The detection position (first detection position) of the corneal apex position Mo is obtained (for example, see FIG. 4). Then, the control unit 80 obtains a detection position (second detection position) of the corneal apex position Mo in the anterior segment image acquired at the next frame rate after acquiring the reference image, and determines the corneal apex position Mo in the reference image. The amount of change Hxy with respect to the detected position (the amount of deviation of the second detected position with respect to the first detected position) is obtained. Then, the control unit 80 determines whether or not the change amount Hxy exceeds a predetermined change amount HSxy (see FIG. 5).

  Further, when the amount of change Hz is obtained in the Z direction, an image ratio S1 (a / b) between the image interval a of the index images Ma and Me and the image interval b of the index images Mh and Mf in the reference image is obtained (FIGS. 3A and 3B). 6). Then, the control unit 80 obtains the image ratio S2 (a / b) in the anterior segment image acquired at the next frame rate after acquiring the reference image. Then, it corresponds to the working distance Z1 (first working distance) between the subject eye and the imaging unit 3 corresponding to the image ratio S1 in the reference image and the image ratio S2 in the image acquired at the next frame rate. The working distance Z2 (second working distance) between the subject's eye and the imaging unit 3 is compared, and a change amount Hz (a displacement amount of the second working distance with respect to the first working distance) in the Z direction is obtained. In this case, the relationship between the working distance Z from the corneal apex position to the infrared light source 53 and the image ratio S (a / b) is obtained in advance and stored in the memory 85. Then, the control unit 80 determines whether or not the change amount Hz exceeds a predetermined change amount HSz.

  The amount of change in the relative position when the relative position of the subject's eye and the imaging unit 3 deviates small in a short time due to fine adjustment of the imaging position by the examiner's operation or fine fixation of the subject's eye, and the subject The amount of change in the relative position when the relative position of the subject's eye and the imaging unit 3 greatly deviates in a short time due to a change in the eye gaze direction, an operator's operation error, etc. A change amount that can be determined is set as a predetermined change amount HSxy (HSz).

  Here, when it is detected during the fine adjustment of the photographing position by the examiner that the alignment deviation amount Δd in the XY directions exceeds the alignment allowable range C, the control unit 80 detects as described above. If the change amount Hxy is equal to or greater than the predetermined change amount HSxy (see FIG. 5A), the control unit 80 controls the drive of the drive unit 6 so that the deviation amount Δd satisfies the alignment allowable range C. The photographing unit 3 is moved in the X and Y directions, and when the deviation amount Δd satisfies the alignment allowable range C, the driving of the driving unit 6 is stopped.

  On the other hand, if the detected change amount Hxy is less than the predetermined change amount HSxy (see FIG. 5B), the control unit 80 operates the drive unit 6 even if the deviation amount Δd exceeds the allowable range C. Is stopped (drive of the drive unit 6 is prohibited). In other words, even if the deviation amount Δd exceeds the allowable range C, if it is determined that the detected change amount H is less than the predetermined change amount HS, the control unit 80 sets the alignment allowable range C wider. To do.

  When it is detected that the alignment deviation amount Δd in the Z direction exceeds the alignment allowable range C, the control unit 80 detects that the change amount Hz detected as described above is equal to or greater than the predetermined change amount HSz (see FIG. 6 (a)), the control unit 80 controls the driving of the driving unit 6 to move the photographing unit 3 in the Z direction so that the displacement amount Δd satisfies the alignment allowable range C, and the displacement is performed. When the amount Δd satisfies the alignment allowable range C, the drive of the drive unit 6 is stopped.

  If the detected change amount Hz is less than the predetermined change amount HSz (see FIG. 6B), the control unit 80 operates the drive unit 6 even if the deviation amount Δd exceeds the allowable range C. Is in a stopped state.

  The control unit 80 prohibits the operation of the drive unit 6 when the alignment deviation amount Δd exceeds the allowable range C in a state where the detected change amount H is less than the predetermined change amount HS. When the deviation amount Δd exceeds the allowable range C and the change amount H exceeds the predetermined change amount HS, the operation prohibition of the drive unit 6 is canceled and the automatic alignment is operated.

  When the shooting position is finely adjusted as described above and a trigger signal for starting shooting is issued, the control unit 80 drives the insertion / removal mechanism 39 to disengage the flip-up mirror 34 from the optical path, thereby inserting / removing mechanism. By driving 66, the dichroic mirror 24 is separated from the optical path, and the photographing light source 14 emits light. At this time, a fundus image is captured by the two-dimensional image sensor 35 and the captured image data is stored in the memory 85. Then, the control unit 80 switches the display screen of the monitor 8 to a color fundus image.

  In this way, when the alignment is largely deviated against the examiner's intention, the photographing unit 3 is returned to the photographing position where fine adjustment by the examiner is possible by the automatic alignment operation. When the alignment is greatly shifted due to the examiner's intention, the examiner can finely adjust the shooting position without being restricted by automatic alignment, so a good fundus image with little flare and illumination unevenness can be obtained. You can shoot smoothly. In this case, flare and illumination unevenness are likely to occur, which is particularly effective during peripheral photographing and photographing of cataract eyes.

  In the above configuration, during fine adjustment of the photographing position by the examiner, the alignment deviation may become too large to grasp the alignment state. Therefore, a predetermined switch (prohibition release switch) provided in the switch 84 may be used. When the command signal for canceling the drive prohibition is issued, the prohibition control is cancelled, and the drive unit 6 is forced to operate so that the deviation amount Δd falls within the allowable range C.

  In the above description, the driving of the manual movement mechanism is detected based on the detection result of misalignment. However, the operation member (for example, joystick, trackball, etc.) is operating by the operator's manual operation. You may provide the detection part which detects that there exists in a manual movement mechanism. In this case, the control unit 80 may detect the driving of the manual movement mechanism when it is detected that the operation member is operating based on the detection signal output from the detection unit.

  FIG. 9 is a diagram illustrating the X operation detection unit 300 that detects that the operation member is operating in the X direction. In FIG. 9, the moving table 2 on which the photographing unit 3 is arranged is configured to be moved to the left and right with respect to the base 1 by the tilting operation of the joystick 4 in the left and right direction. Two pulleys 320 and 321 are attached to the base 1 side, and a wire 322 is passed between the pulleys. The wire is fixed to a block 310 of a part of the movable table 2. Yes. Further, the wire 322 is wound around the rotary plate of the potentiometer 323. Here, when the joystick 4 is tilted, the movable table 2 is moved in the left-right direction, so that the potentiometer 323 rotates via the wire 322, and an operation signal is output from the potentiometer 323 to the control unit 80. . In this case, the control unit 80 detects that the joystick 4 is operating in the X direction based on the operation signal output from the potentiometer 323, and thereby detects the driving of the manual movement mechanism. In the Z direction, it can be detected that the operating member is operating in the Z direction by using a mechanism similar to that shown in FIG.

  As a Y operation detection unit that detects that the operation member is operating in the Y direction, a rotation detection unit (built in the joystick 4) that detects an operation signal of the rotary knob 4a provided to move the photographing unit 3 up and down. Can be used). In this case, when the rotary knob 4 a is rotated, an operation signal is output from the rotation detection unit to the control unit 80. In this case, the control unit 80 detects that the joystick 4 is operating in the Y direction based on the operation signal output from the rotation detection unit.

  When such an operation detection unit is used, the control unit 80 is operating the joystick 4 based on a detection signal output from at least one of the X operation detection unit, the Z operation detection unit, and the Y operation detection unit. When the alignment deviation amount Δd exceeds the permissible range C in the state where it is detected that, the operation of the drive unit 6 is prohibited. Alternatively, whether or not the alignment deviation amount Δd exceeds the allowable range C is determined in each of the XYZ directions, the X operation detection unit for the X direction, the Z operation detection unit for the Z direction, and the Y operation detection unit for the Z direction. Based on the detection signal output from, whether or not the automatic alignment is operable is determined. For example, when it is detected that the joystick 4 is operating in the Y direction, when the amount of alignment deviation Δd in the Y direction exceeds the allowable range C, the operation of the drive unit 6 is prohibited.

  If it does in this way, the drive of a manual movement mechanism part can be detected directly. In this case, the operation of the drive unit 6 is prohibited when the displacement amount Δd exceeds the allowable range C when the drive of the manual movement mechanism unit is detected regardless of the fine movement operation or coarse movement operation by the examiner. Is done.

  In the above description, the manual movement mechanism in which the movable table 2 is mechanically moved horizontally with respect to the base 1 by the tilting operation to the joystick 4 has been described as an example. However, the operation signal (operation amount to the operation member) , Operation speed, etc.) are electrically detected, and the electric drive mechanism is driven based on the detection signal to move the photographing unit 3 in the XZ direction (electric joystick mechanism, trackball mechanism, etc.). The invention can be applied.

  Hereinafter, a description will be given of a modification example in the case where automatic alignment is performed using the alignment allowable range C set so as to allow fine adjustment of the photographing position by the examiner.

  Here, the control unit 80 stores the alignment deviation direction when the detected alignment deviation is outside the predetermined alignment allowable range in the memory 85, and performs XYZ driving so that the alignment deviation falls within the predetermined alignment allowable range. After driving the unit 6, the XYZ driving unit 6 is not driven when the alignment deviation is out of the predetermined alignment allowable range again in the misalignment direction stored in the memory 85 (the driving of the XYZ driving unit is prohibited). To do).

More specifically, the control unit 80 stops the automatic alignment operation until the alignment deviation amount Δd in the XY directions exceeds the allowable range C, and the deviation amount Δd deviates from the allowable range C. When the determination condition is satisfied, the automatic alignment is started.
Here, after completion of automatic alignment using the allowable range A, after the alignment allowable range C is set, when it is detected that the deviation amount Δd exceeds the alignment allowable range C, this is the first time. For example, the automatic alignment is activated to drive the drive unit 6 so that the deviation amount Δd satisfies the allowable range C.
At this time, the control unit 80 stores in the memory 85 the direction of misalignment when the deviation amount Δd exceeds the allowable range C, and the deviation amount Δd satisfies the allowable range C by the automatic alignment operation. Thereafter, as shown in FIG. 10, the allowable alignment range (allowable range D) is increased with respect to the direction of misalignment stored in the memory 85 (for example, the hatched portion in FIG. 10).

  Then, when it is detected again that the deviation amount Δd exceeds the alignment allowable range C with respect to the direction of the alignment shift stored in the memory 85, the control unit 80 falls within the newly set allowable range D. If there is, the drive of the drive unit 6 is prohibited, and when the newly set allowable range D is exceeded, the drive unit 6 is driven so that the deviation amount Δd satisfies the allowable range D.

  In the above description, the alignment deviation is detected using the alignment index received on the two-dimensional image sensor 65. However, the anterior segment image received on the two-dimensional image sensor 65 is used. An alignment shift may be detected. For example, the pupil center position in the anterior ocular segment image is detected by image processing based on the light reception signal from the two-dimensional image sensor 65, and the alignment deviation is obtained from the positional relationship between the detected pupil center position and the alignment reference position O1. It is possible.

It is an external appearance block diagram of the fundus camera which concerns on this embodiment. It is a schematic block diagram of the optical system and control system accommodated in an imaging | photography part. It is a figure which shows an example of an anterior ocular segment observation screen. It is a figure which shows an example of the method of detecting the alignment shift | offset | difference of the imaging | photography part with respect to a to-be-tested eye. It is a figure which shows an example in the case of detecting the drive of a manual movement mechanism part regarding XY direction. It is a figure which shows an example in the case of detecting the drive of a manual movement mechanism part regarding a Z direction. It is a flowchart which shows an example in the case of performing automatic alignment based on a drive detection signal. It is a figure which shows an example of a fundus observation screen. It is a figure explaining the operation detection part which detects that the operation member is operating | moving regarding X direction. It is a figure which shows an example in the case of widening the alignment tolerance | permissible_range regarding the direction of the misalignment memorize | stored in memory.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Image pick-up part 4 Joystick 6 XYZ drive part 8 Monitor 30 Fundus observation / imaging | photography optical system 60 Anterior eye part observation optical system 65 Image pick-up element 80 Control part 85 Memory 300 X operation detection part

Claims (5)

An imaging unit in which an imaging optical system that images the fundus of the subject and an observation optical system that has an image sensor and observes the fundus;
A manual movement mechanism that has an operation member and moves the imaging unit relative to the eye of the subject by operating the operation member;
A sensor for detecting the driving of the manual movement mechanism,
An automatic movement mechanism having an electric motor for moving the imaging unit relative to the eye of the subject;
A monitor,
A display control unit for processing an output signal from the image sensor and displaying an observation image of the fundus on the monitor;
An alignment detection optical system having a light receiving element for detecting misalignment of the imaging unit with respect to the eye of the subject;
A movement control unit that detects an alignment shift of the imaging unit with respect to the subject's eye based on a light reception signal output from the light receiving element, and outputs a drive signal to the automatic movement mechanism unit based on the detection result;
In a fundus camera having
In the case where the detected misalignment is within a predetermined alignment allowable range outside the predetermined alignment allowable range, the movement control unit,
When the drive of the manual movement mechanism unit is not detected by the sensor, the automatic movement mechanism unit is driven so that the misalignment falls within an allowable range,
The fundus camera, wherein the automatic movement mechanism is not driven when the driving of the manual movement mechanism is detected by the sensor. The fundus camera of claim 1,
The light receiving element of the alignment detection optical system is a two-dimensional light receiving element capable of acquiring an anterior segment image of the subject's eye,
The fundus camera is characterized in that the alignable range is set wider than that in the case where the misalignment is detected by capturing an image of the fundus. The fundus camera of claim 2,
The sensor detects a change amount of a relative position between the subject eye and the imaging unit per predetermined time based on a light reception signal from the light receiving element, and when the detected change amount is less than a predetermined change amount A fundus camera that detects driving of the manual movement mechanism. The fundus camera of claim 2,
The manual movement mechanism has an operation detection unit that detects that the operation member is operating by a manual operation of an examiner, and the sensor is operated based on a detection signal output from the operation detection unit. A fundus camera that detects driving of a manual movement mechanism when it is detected that it is in operation. The fundus camera of claim 1,
The movement control unit includes a deviation direction storage unit that stores a direction of the alignment deviation when the detected alignment deviation is outside a predetermined alignment allowable range so that the alignment deviation falls within the predetermined alignment allowable range. After driving the automatic movement control unit,
The fundus camera is characterized in that the automatic movement mechanism is not driven when the alignment deviation again falls outside a predetermined alignment allowable range in the alignment deviation direction stored by the deviation direction storage means.