JP5193614B2 - Ophthalmic equipment - Google Patents

Description

  The present invention provides an ophthalmic apparatus that includes an alignment system and an observation optical system as an optical system, such as a fundus camera, and uses an alignment target recognized by the observation optical system, and aligns the apparatus main body with respect to an eye to be examined. About.

  An example of this type of ophthalmologic apparatus is a fundus camera. In this fundus camera, the illumination light of the illumination light source of the illumination system is projected from the objective lens onto the eye to be examined, and the reflected light from the eye to be examined is guided to the observation camera and the photographing camera through the objective lens and the photographing aperture. It is usual to have an observation optical system and a photographing optical system.

  In such a fundus camera, the reflected light from the surface of the objective lens is mixed as harmful light in the photographing optical system, causing flare and central ghost, so that clear fundus observation and photographing cannot be performed.

  Here, the “center ghost” is referred to as a center ghost because the reflected light from the surface of the objective lens is mixed as harmful light in the observation optical system and the photographing optical system and is generated in a dot shape at the center of the screen. This central ghost is a pupil division optical system in which the fundus camera illuminates from the peripheral part on the eye pupil to be examined and extracts the observation / photographing light from the central part, and the objective lens is common for illumination and observation / photographing. This is an unavoidable problem.

On the other hand, conventionally, in order to remove such harmful light, when the lens surface of the objective lens is considered as a reflecting surface, the photographing aperture is positioned at the position of the illumination system conjugate with the position where the image of the photographing aperture is formed. It has been proposed to provide a small black spot that covers the image of the opening. Note that a plurality of small black spots may be provided according to the shape of the objective lens (see, for example, Patent Document 1).
Japanese Examined Patent Publication No. 60-57852

  However, in the conventional fundus camera, even if a small black spot is provided in the illumination system, the monitor image from the observation camera cannot eliminate, for example, the ring-shaped or dot-shaped central ghost, In addition, since the central ghost is very similar to the alignment luminescent spot, the central ghost is erroneously recognized as the alignment luminescent spot, or the central ghost is erroneously detected as the alignment luminescent spot. As a result, there is a problem that the alignment adjustment malfunctions during manual or automatic alignment.

  In particular, in a fundus camera having an automatic photographing mode, a flash photographing operation is performed while the center ghost is erroneously detected as an alignment bright spot. For this reason, the frequency of shooting mistakes increases, and this is a serious problem that loses the reliability and effectiveness of the automatic shooting mode.

  The present invention has been made paying attention to the above problem, and an ophthalmic apparatus that can reliably avoid malfunction of alignment operation due to erroneous recognition or misdetection of the central ghost as an alignment target during alignment operation. The purpose is to provide.

In order to achieve the above object, in the present invention, as an optical system, an illumination optical system for illuminating a subject to be photographed and an alignment system for projecting an alignment target for aligning the apparatus main body with respect to the eye to be examined And an observation optical system including an observation camera that adds an alignment target to an image to be imaged of the eye to be examined and forms an observation video signal.
A difference between a lighting image acquired from the observation optical system with the alignment light source included in the alignment system turned on and a light-off image acquired from the observation optical system with the alignment light source included in the alignment system turned off. look, have a alignment target candidates detected by the luminance distribution characteristics of said difference image, determining alignment target determination processing unit and the true alignment target recognized by the observation image,
The alignment target determination processing unit includes a background extinguishing image storage unit that stores a background extinguishing image of an alignment evaluation range acquired from the observation optical system in a state where an alignment light source included in the alignment system is extinguished. After storing the extinguished image, the background extinguished image stored in the background extinguished image storage unit is used when a difference from the observed image is obtained for alignment target determination .

Therefore, in the ophthalmic apparatus of the present invention, the alignment target determination processing unit includes a lighting image acquired from the observation optical system in a state where the alignment light source included in the alignment system is lit, and an alignment light source included in the alignment system. The difference between the extinguished image acquired from the observation optical system in the extinguished state is obtained, and the alignment target candidate detected by the luminance distribution characteristic of the difference image is determined as the true alignment target recognized by the observed image. Is done.
That is, the central ghost is generated when the illumination light of the illumination optical system is reflected by the objective lens and enters the shared observation optical system and photographing optical system. For this reason, the lighting image acquired from the observation optical system in a state where the alignment light source included in the alignment system is turned on has luminance distribution characteristics due to the alignment target and the central ghost. On the other hand, the extinguished image acquired from the observation optical system in a state where the alignment light source included in the alignment system is extinguished has a luminance distribution characteristic due to the central ghost. Therefore, when the difference processing between the two images is performed, the influence of the central ghost is removed, and the luminance distribution characteristic based only on the alignment target can be acquired.
As a result, during the alignment operation, it is possible to reliably avoid erroneous operation of the alignment operation due to erroneous recognition or erroneous detection of the center ghost as an alignment target.
In addition, after storing the background unlit image in the alignment evaluation range in the background unlit image storage unit, when obtaining a difference from the observation image for alignment target determination, the background unlit image stored in the background unlit image storage unit is Used. For this reason, for example, compared with the case where the alignment light source is blinked each time the difference process is performed without using the stored image, the blinking frequency of the alignment light source is reduced, and the visual burden on the examiner can be reduced.

  Hereinafter, the best mode for realizing an ophthalmologic apparatus of the present invention will be described based on Example 1 shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram illustrating a non-mydriatic fundus camera (an example of an ophthalmologic apparatus) according to the first embodiment. Here, the “non-mydriatic retinal camera” refers to a retinal camera that takes a photo of the fundus by observing the fundus and applying a flash after performing mydriasis to some extent in the dark room without using mydriatic drugs. Say. The advantage of this non-mydriatic fundus camera is that there is no visual inconvenience after the examination, and it is used not only in ophthalmology but also in internal medicine and medical examinations for simplicity. The disadvantage is that the mydriatic is insufficient, so that only the central part of the retina can be photographed. For this reason, the response | compatibility to the case of the small pupil by diabetic retinopathy etc. is requested | required.

  As shown in FIG. 1, the non-mydriatic fundus camera of the first embodiment includes an apparatus base 1, a gantry 2, an apparatus body 3, a chin rest 4, an external fixation target 5, and a photographing CCD camera 6. (Camera), mouse / 10 keyboard 7, printer 8, and personal computer 9.

  The device base 1 is installed horizontally on a device table (not shown), and is provided with a power plug and a plurality of connection terminals. The device base 1 includes a power supply unit, chin rest PCB, relay PCB, and the like. “PCB” is an abbreviation for Printed Circuit Board, which means a printed circuit board such as an IC.

  The gantry 2 is provided to be movable in the left-right direction, the front-rear direction, and the up-down direction with respect to the apparatus base 1. An operation panel 2a, a joystick 2b, a photographing switch 2c, and the like are provided at a position on the examiner side of the gantry unit 2.

  The apparatus main body 3 is integrally provided on the top of the gantry 2, and a focusing handle 3 a is provided at a side position of the apparatus main body 3. Further, an observation monitor 3b (for example, a 6.5-type color liquid crystal monitor) which is a component of the observation LCD unit 31 (see FIG. 5) is provided at the examiner side position of the apparatus main body 3. Note that “LCD” is an abbreviation for Liquid Crystal Display and refers to a liquid crystal display.

  The chin rest 4 is provided so that the position in the vertical direction can be adjusted with respect to the apparatus base 1 and receives the subject's chin and forehead to fix the position of the eye to be examined. The chin rest 4 is provided with an external fixation target 5 for fixing the line of sight of the subject.

  The photographing CCD camera 6 is set externally at the upper position of the apparatus main body 3 and performs flash photography of the fundus using the autoshoot function of the non-mydriatic fundus camera of the first embodiment. A commercially available APS size digital camera is used as the photographing CCD camera 6. The photographing CCD camera 6 is supplied with power from a power supply unit built in the apparatus base 1.

  The mouse / 10 keyboard 7, the printer 8, and the personal computer 9 are connected to a plurality of connection terminals of the apparatus base 1 via cables. The personal computer 9 is connected to a PC monitor 9a that can perform fundus observation on a large screen.

  FIG. 2 is a plan view showing an operation panel set on the gantry in the non-mydriatic retinal camera of the first embodiment. Hereinafter, each switch set on the operation panel 2a will be described.

  As shown in FIG. 2, the operation panel 2a set in the gantry unit 2 of the non-mydriatic fundus camera of the first embodiment includes a joystick 2b, a photographing switch 2c, a menu switch 201, a split switch 202, and a photographing light amount. Correction switch 203, observation light quantity correction switch 204, chin rest vertical movement switch 205, ID input switch 206, image deletion switch 207, image reproduction switch 208, small pupil switch 209, fixation changeover switches 210, 211, 212 , An auto ON / OFF switch 213 and a zoom switch 214 are provided.

  The joystick 2b is an operating means for moving the gantry 2 and the apparatus main body 3 in the left-right direction (X direction), the up-down direction (Y direction), and the front-rear direction (Z direction) with respect to the apparatus base 1 during a manual alignment operation. is there. The left-right direction and the front-rear direction are moved by holding the joystick 2b and tilting it in the left-right direction or the front-rear direction to be moved. At this time, the frame front / rear detection switch 215 and the frame left / right detection switch 216 are turned on (see FIG. 5). Further, the operation ring at the upper part of the joystick 2b is moved upward by rotating it to the right, and moved downward by rotating it to the left.

  The photographing switch 2c is provided at the position of the upper end portion of the joystick 2b, and becomes a photographing shutter switch for the fundus when the examiner performs a switch operation. In addition to the shooting function, the shooting switch 2c also performs review cancellation and power save cancellation.

  The menu switch 201 performs menu ON / OFF.

  The split switch 202 performs “split ON / OFF” or “fixation target switching”. To change this function, use “SPLIT SWITCH” in the initial menu.

  The photographing light amount correction switch 203 corrects the photographing light amount. From the left in FIG. 2, there are a minus correction switch, a reset switch, and a plus correction switch.

  The observation light amount correction switch 204 corrects the observation light amount. From the left in FIG. 2, a minus correction switch and a plus correction switch.

  The chin rest vertical movement switch 205 moves the chin rest 4 up and down. From the left in FIG. 2, a chin rest lowering switch and a chin rest upper moving switch.

  The ID input switch 206 is a switch that moves to an ID input screen.

  The image deletion switch 207 is turned ON / OFF when deleting the reviewed photographed image.

  The image reproduction switch 208 can reproduce the image of the digital still camera 6 by turning on the switch. Each time the fixation switch 210 is turned on, the image taken one sheet before is reproduced. Each time the fixation changeover switch 212 is turned on, an image taken one image later is reproduced. Turn the switch off to return to the observation screen.

  The small pupil switch 209 performs IN / OUT of the small pupil stop by turning the switch ON / OFF. It functions independently even when the auto ON / OFF switch 213 is ON. When turned ON, ◎ is displayed on the screen of the observation monitor 3b. When set to the digital magnification interlock mode, the digital pupil is saved to the image net at a digital magnification of 30 ° when the small pupil aperture is ON. When printing, an image at a digital zoom ratio of 30 ° is printed out. When digital zoom non-interlocking mode is set, digital zoom is not changed even when the small pupil iris is turned on, and the angle remains at 45 °. The small pupil switch 209 also serves as a switch for moving the selection cursor upward when a menu or ID is input.

  The fixation changing switch 210 switches to the blinking (lighting) position immediately before the blinking (lighting) position of the current internal fixation target. The fixation change switch 210 also serves as a switch for moving the selection cursor to the left when inputting a menu or ID.

  The fixation switching switch 211 switches from the blinking (lighting) position of the current internal fixation target to the first blinking (lighting) position. The fixation changing switch 211 serves as both a print switch and an enter switch. When the print switch is turned ON, the reviewed image is printed. If it is set to ON when automatic printing is set in the menu setting and the print display is displayed on the observation screen, printing is canceled. In the case of an enter switch, selection items and characters are determined when a menu or ID is input.

  The fixation changing switch 212 switches to the first blinking (lighting) position of the current blinking (lighting) position of the internal fixation target. Note that the fixation changeover switch 212 also serves as a switch for moving the selection cursor to the right when inputting a menu or ID.

  The auto on / off switch 213 and the auto shoot function / auto focus function / auto small pupil function are turned on / off. Here, ON / OFF of each function can be set by a menu. The auto ON / OFF switch 213 also serves as a switch for moving the selection cursor downward when inputting a menu or ID.

  The zoom switch 214 is a switch for switching the shooting angle of view between 30 ° and 45 ° in order to perform fundus shooting with two zooms.

  FIG. 3 is an image diagram showing display contents displayed on the observation monitor set in the apparatus main body of the non-mydriatic fundus camera of the first embodiment. Hereinafter, each display content will be described.

  In the case of the non-mydriatic fundus camera of the first embodiment, the information of the apparatus main body 3 and the information of the digital still camera 6 are displayed on the observation monitor 3b as shown in FIG. The display during observation, review, playback, and menu includes patient ID 301, left and right eyes 302, xenon charge 303, photographing light amount correction 304, photographing light amount level 305, auto display 306, and angle of view. 307, fixation position 308, () scale 309, alignment bright spots 310 and 310 (alignment target), split bright lines 311 and 311 (split target), observation light quantity level 312, and small pupil stop 313 .

  The patient ID 301 displays a patient ID of an image to be captured. The left and right eyes 302 display the left and right eyes (R, L) of the subject to be photographed. The xenon charge 303 blinks during charging and lights up when charging is completed. The photographing light amount correction 304 displays a correction amount (+4 to −4) at the panel switch 217 (see FIG. 5). The photographing light amount level 305 displays the photographing light amount (0.8 ws to 45 ws).

  The auto display 306 is displayed when autoshoot / autofocus / auto small pupil switching is ON. The angle of view 307 displays the image magnification to be taken. For example, when digital zooming is set to the small pupil aperture linked mode, 30 ° is displayed when the small pupil aperture is ON. The fixation position 308 displays an internal fixation position pattern by blinking the selected fixation position.

  The () scale 309 is displayed as a position for matching the alignment bright spot. The alignment bright spots 310 and 310 are displayed as targets for adjusting the working distance of the subject. The split bright lines 311 and 311 are displayed as targets for adjusting the diopter of the subject. The observation light quantity level 312 displays the observation light quantity level in five stages. The small pupil stop 313 displays ◎ when the small pupil stop is inserted.

  FIG. 4 is an optical arrangement diagram showing an optical system built in the apparatus main body 3 in the non-mydriatic fundus camera of the first embodiment. Hereinafter, the arrangement configuration of the optical system of the non-mydriatic retinal camera will be described.

  Inside the apparatus main body 3, as shown in FIG. 4, an illumination optical system 10 for illuminating the fundus oculi Ef of the eye E to be examined, an imaging optical system 20 for photographing the fundus oculi Ef, and observation for observing the fundus oculi Ef An optical system 30, an alignment system 40 for performing relative positioning of the apparatus main body 3 with respect to the eye E, and an internal fixation system 50 for projecting a fixation target onto the fundus oculi Ef to fixate the eye E. A split optical system 60 for focusing the optical system on the fundus oculi Ef is provided.

  The illumination optical system 10 is an illumination optical system that illuminates the fundus oculi Ef with infrared light during observation and illuminates the fundus oculi Ef with visible light during imaging. This illumination optical system 10 includes an objective lens 11, a perforated mirror 12, a relay lens 13, a reflecting mirror 14, a relay lens 15, and a ring aperture plate 16 having a ring aperture 16a maintained in a conjugate relationship with the pupil of the eye E to be examined. And a xenon lamp 17a as an imaging light source, an IR filter 18, a condenser lens 19, and a halogen lamp 17b as an observation illumination light source. Further, when the distance W between the eye E and the objective lens 11 is arranged at an appropriate working distance, the perforated mirror 12 is arranged at a position conjugate with the cornea C of the eye E.

  The photographing optical system 20 is an optical system for photographing the fundus oculi Ef illuminated by the illumination optical system 10 as a still image. This photographing optical system 20 includes an objective lens 11, a perforated mirror 12, a focusing lens 21, an imaging lens 22, a reflecting mirror 23, a field lens 24, a reflecting mirror 25, a relay lens 26, CCD 6a of the CCD camera 6 for photographing.

  The observation optical system 30 is an optical system for observing the fundus oculi Ef illuminated by the illumination optical system 10, and is configured to be branched by a quick return mirror 33 from the middle of the optical path of the photographing optical system 20. The observation optical system 30 includes a reflection mirror 35, a relay lens 36, and a CCD 37a of an observation CCD camera 37 (observation camera).

The alignment system 40 is for projecting alignment bright spots 310 and 310 that are alignment targets toward the eye E to be examined. The alignment system 40 includes an alignment LED 41 as an alignment light source, a light guide 42 that guides the light from the alignment LED 41, a reflecting mirror 44 that reflects the light emitted from the light guide 42 and guides it to the two-hole aperture 43, and a relay. The lens 45, the branching half mirror 46 from the photographing optical system 20, the perforated mirror 12, and the objective lens 11 are included. The two-hole aperture 43 separates and projects the alignment bright spots 310 and 310 based on the alignment light flux onto the eye E when the working distance W deviates from the appropriate position.
That is, the alignment light beam emitted from the exit end 42a of the light guide 42 is guided to the two-hole stop 43 reflected by the reflecting mirror 44, and the alignment light beam passing through the holes 43a and 43a of the two-hole stop 43 is relayed. Guided to the lens 45. The alignment light flux that has passed through the relay lens 45 is reflected by the half mirror 46 toward the perforated mirror 12. The relay lens 45 temporarily forms an intermediate image at the exit end 42 a of the light guide 42 at the center position X of the hole 12 a of the perforated mirror 12. A pair of alignment bright spots 310 and 310 that form an alignment target imaged at the center position X of the hole 12a are guided to the cornea C of the eye E through the objective lens 11.

  The internal fixation system 50 is an optical system that projects a fixation target to be guided to the central portion of the eye E and its peripheral portion, and transmits infrared light from the middle of the optical path of the observation optical system 30. The light is branched by a dichroic mirror 53 having a characteristic of reflecting visible light. The fixation system 50 includes an internal fixation LED 51 as an internal fixation light source, a mask plate 52, and a dichroic mirror 53. The internal fixation LED 51 includes, for example, three LEDs arranged in the center and eight LEDs arranged at equal intervals on the circumference around the three LEDs. Is done.

  The split optical system 60 is a projection optical system for split emission lines 311, 311; a split LED 61 as a split light source; a reflecting rod 62 that is provided in the optical path of the illumination optical system 10 and reflects light from the split LED 61; Have The reflector 62 is detachably inserted at a position that can be optically conjugated with the fundus oculi Ef of the eye E (see, for example, JP-A-9-66032). In the split optical system 60, the reflecting mirror of the reflecting rod 62 of the split bright lines 311 and 311 and the fundus oculi Ef are always optically conjugate with each other in the Z direction of the focusing lens 21 of the observation optical system 30 and the photographing optical system 20. In conjunction with the movement, the illumination optical system 10 moves in the optical axis direction. When the fundus oculi Ef and the split luminescent lines 311 and 311 are not conjugated, as shown in FIG. 3, the split luminescent lines 311 and 311 appear to be separated into two in the left-right direction. It can be performed.

  FIG. 5 is an electrical block diagram illustrating a control system built in the apparatus base 1, the gantry 2, and the apparatus body 3 in the non-mydriatic fundus camera of the first embodiment. Hereinafter, the configuration of the electric control system of the non-mydriatic fundus camera will be described.

  As shown in FIG. 5, the apparatus base 1 includes a chin rest PCB 101, a chin rest DC motor 102, an external fixation LED 103, an AC power supply plug 104, a fuse 105, a power supply switch 106, and a power source. A supply switching unit 107 and a relay PCB 108 are provided. The relay PCB 108 includes a numeric keypad PS2 connector 109, a printer USB connector 110, a mouse USB connector 111, and an image net USB connector 112.

  As shown in FIG. 5, the gantry 2 includes an imaging switch 2c, a menu switch 201, a split switch 202, an imaging light amount correction switch 203, an observation light amount correction switch 204, and a chin rest vertical movement switch 205. , ID input switch 206, small pupil switch 209, fixation switch 210, 211, 212, auto ON / OFF switch 213, zoom switch 214, gantry front / rear detection switch 215, gantry left / right detection switch 216, panel switch 217.

  As shown in FIG. 5, the apparatus main body 3 includes a photographing CCD camera 6, a xenon lamp 17a, a halogen lamp 17b, an observation LCD unit 31, an observation CCD camera 37, a main body PCB 315, and a board PC316. A shooting camera relay PCB 317, a DC power supply PCB 318, and a capture board 319. The DC power supply PCB 318 includes a halogen lamp control unit 318a and a xenon lamp control unit 318b.

  As information input means to the main body PCB 315, as shown in FIG. 5, a blink detection PCB 320, a green filter detection switch 321, a diopter correction lens detection switch 322, a lamp house cover detection switch 323, and an alignment motor detection sensor 324, a quick mirror motor detection sensor 325, an autofocus motor (+) detection sensor 326, and an autofocus motor (−) detection sensor 327.

  As shown in FIG. 5, the control command output means from the main body PCB 315 includes a cooling fan 328, an alignment motor 330 (alignment actuator), a quick mirror motor 331, an autofocus motor 332 (autofocus actuator), and a crystalline lens. A diaphragm drive solenoid 333, an anterior segment switching drive solenoid 334, a reflector driving solenoid 335, a split LED 61, an alignment LED 41, a hand illumination LED 336, and an internal fixation LED 51 are provided.

  The main body PCB 315 and the board PC 316 exchange data by serial communication. The main body PCB 315 and the photographing camera relay PCB 317 exchange data by bidirectional communication. The board PC 316 and the shooting camera relay PCB 317, the board PC 316 and the relay PCB 108, and the shooting camera relay PCB 317 and the relay PCB 108 are respectively exchanged by bidirectional communication.

The main body PCB 315 has the following functions.
(1) Sensor detection blink / green filter / diopter correction lens / lamp house cover / alignment quick mirror / auto focus motor.
(2) Motor drive alignment / Quick mirror / Auto focus motor drive control.
(3) Solenoid drive lens aperture / anterior eye part switching / reflector solenoid drive control.
(4) LED lighting Controls lighting / flashing of split / alignment / hand illumination / internal fixation.
(5) Reading switch signals Various switch signals are read from the gantry 2.

The board PC 316 (single board computer) has the following functions.
(1) Direct print function A function for directly transferring an image taken by the CCD camera 6 for photography to the printer 8. Although the PictBridge function is also implemented in the main body of the photographing CCD camera 6, it is necessary to operate the main body of the photographing CCD camera 6 when printing, and the operability is poor. Therefore, the operation is simplified by including a printout function in a series of photographing operations.
(2) Autofocus function A function that realizes autofocus by analyzing the states of split bright lines 311 and 311 on the observation video signal obtained from the CCD 37a of the CCD camera 37 for observation. By executing the analysis of the video signal in the board computer, autofocus can be executed without using a dedicated PC board.
(3) Auto-shoot function (= automatic flash shooting function)
This is a function for analyzing the states of alignment bright spots 310 and 310 and split bright lines 311 and 311 on the observation video signal obtained from the CCD 37a of the observation CCD camera 37 and realizing an automatic flash photographing operation. Similar to the above autofocus, the autoshoot can be executed without using the dedicated PC board by executing the analysis of the video signal in the board computer.
(4) Auto small pupil switching function This means a function of analyzing the state of split bright lines 311 and 311 on the observation video signal obtained from the CCD 37a of the observation CCD camera 37, and automatically inserting a diaphragm in the case of a small pupil. Similar to the autofocus described above, the analysis of the video signal is executed by the board computer, so that the automatic small pupil switching can be executed without using a dedicated PC board.
(5) Monitor display function An observation image and a photographed image are displayed on the observation monitor 3b.

The DC power supply PCB 318 has the following functions.
(1) The halogen lamp controller 318a controls the light emission of the halogen lamp 17b.
(2) The light emission of the xenon lamp 17a is controlled by the xenon lamp control unit 318b.

  FIG. 6 is a flowchart illustrating a flow of an autofocus control operation executed by the board PC 316 in the non-mydriatic fundus camera of the first embodiment. FIG. 7 is a flowchart illustrating the flow of autoshoot control operations (including repetition of the flow of autofocus control operations) executed by the board PC 316 in the non-mydriatic fundus camera of the first embodiment. Hereinafter, each step will be described (automatic photographing control means).

  In step S1, it is determined whether or not the auto ON / OFF switch 213 is ON. If YES (automatic ON / OFF switch ON) is determined, the process proceeds to step S2. If NO (automatic ON / OFF switch OFF) is determined, the determination in step S1 is repeated.

  In step S2, following the determination of the auto ON / OFF switch ON in step S1, it is determined whether or not the anterior ocular segment observation has been switched to the fundus oculi observation. If it is determined YES (anterior ocular segment observation → fundus observation), the process proceeds to step S3. If it is determined NO (no anterior segment observation or fundus observation), the process returns to step S1.

  In step S3, following the determination that the anterior ocular segment observation has been switched to fundus observation in step S2, the fundus observation image obtained from the CCD 37a of the observation CCD camera 37 is captured for one frame via the capture board 319. The process proceeds to step S4.

In step S4, following the acquisition of the fundus observation image in step S3, the barycentric positions of the split bright lines 311 and 311 for autofocus are detected, and the process proceeds to step S5.
Here, the center-of-gravity position detection of the split bright lines 311 and 311 is such that the center point of a region where the luminance is equal to or higher than the threshold is detected as the barycentric position in the luminance distribution characteristics of the split bright lines 311 and 311 in the acquired fundus observation image.

In step S5, following the detection of the center of gravity of the split bright lines 311, 311 in step S4, it is determined whether the number of split bright lines 311, 311 is one or less. When it is determined that the number of split bright lines 311 and 311 is two, the process proceeds to step S6, and when it is determined that the number of split bright lines 311 and 311 is one or less, the process proceeds to step S12.
The number of the split bright lines 311 and 311 is determined based on the number of the center of gravity positions detected in accordance with the detection of the center of gravity position using the luminance distribution characteristics in step S4.

In step S6, following the determination that the number of split bright lines 311 and 311 is two in step S5 or step S15, the difference between the center of gravity positions of the two split bright lines 311 and 311 is calculated, and the amount of motor movement by the autofocus motor 332 is calculated. Confirm and move to step S7.
Here, the motor movement direction as well as the motor movement amount is determined according to the vertical relationship between the left and right split bright lines 311 and 311.

  In step S7, following the determination of the motor movement amount in step S6, the autofocus motor 332 (focusing motor) is driven with the determined motor movement amount and motor movement direction, and the process proceeds to step S8.

  In step S8, following the driving of the focusing motor in step S7, the fundus observation image from the CCD 37a of the observation CCD camera 37 is further captured through the capture board 319 for one frame, and the two split bright lines 311 and 311 are displaced. If recognized, fine adjustment is performed using the autofocus motor 332 in the matching direction, and the process proceeds to step S9.

In step S9, following the autofocus fine adjustment in step S8, it is determined whether or not the positions of the two split bright lines 311 and 311 are within the in-focus range. If YES (in-focus range) is determined, the process proceeds to step S10. If NO (out-of-focus range) is determined, the process returns to step S3.
Here, when the separation amount of the two split bright lines 311 and 311 is, for example, ± 0.5D, it is determined that the positions of the two split bright lines 311 and 311 are within the focusing range.

  In step S10, following the determination that the positions of the two split bright lines 311 and 311 are within the focusing range in step S9, the current motor position of the autofocus motor 332 is stored, and the process proceeds to step S11.

  In step S11, following the determination that the current motor position is stored in step S10 or the number of split bright lines 311 and 311 recognized in the observation image in step S15 is one, focusing is performed by an autofocus operation. Is completed, the process proceeds to step S16 to start the small pupil detection operation and the autoshoot function operation.

  In step S12, following the determination that the number of split bright lines 311 and 311 is 1 or less in step S5, it is determined whether the number of split bright lines 311 and 311 is one or zero. In the case of one, the process proceeds to step S13, and in the case of zero, the process proceeds to step S16 for starting the small pupil detection operation.

  In step S13, following the determination that the number of split bright lines 311 is one in step S12, the difference between the center of gravity position of one split bright line 311 and the focus position of a preset scan line is calculated. Then, the process proceeds to step S14.

In step S14, following the calculation of the difference between the center of gravity position and the focusing position of one split bright line 311 in step S13, the autofocus motor 332 (focusing motor) is driven by the moving amount and moving direction based on the determined difference. Then, the process proceeds to step S15.
Here, the moving direction is determined based on which split bright line 311 of the left and right split bright lines 311 and 311 is detected.

  In step S15, following the driving of the focusing motor in step S14, the fundus observation image is captured again for one frame, and it is determined whether there are two split bright lines 311 and 311 recognized in the observation image. If YES (two split luminescent lines) is determined, the process proceeds to step S6. If NO (one split luminescent line) is determined, the process proceeds to step S11.

  In step S30, following the completion of focusing in step S11 or the determination that the split bright lines 311 and 311 recognized in the observation image in step S12 are zero, the alignment LED 41 (alignment light source) is turned on and off. The process of determining the alignment bright spots 310, 310 based on the difference (FIG. 8) is executed, and the process proceeds to step S16.

In step S16, following the determination process of alignment bright spots 310 and 310 in step S30 or the determination that alignment bright spots 310 and 310 do not match in step S27, the two alignment bright spots 310 and 310 determined in step S30. Is detected, and the process proceeds to step S17.
Here, the center-of-gravity position detection of the alignment bright spots 310 and 310 is performed by detecting the center point of the area where the brightness is equal to or higher than the threshold in the brightness distribution characteristics of the alignment bright spots 310 and 310 determined by the difference processing between the lit image and the unlit image. Like to do.

  In step S17, following the detection of the center of gravity of the two alignment bright spots 310 and 310 in step S18, it is determined whether or not the number of split bright lines 311 and 311 recognized in the observation image is one or less. If YES (one split bright line or zero) is determined, the process proceeds to step S18, and if NO (two split bright lines) is determined, the process proceeds to step S25.

  In step S18, following the determination that the number of split bright lines 311 and 311 recognized in the observation image in step S17 is one or less, one of split bright lines 311 and 311 recognized in the observation image is one or zero. Is determined. If it is determined that the number of split bright lines 311, 311 is one, the process proceeds to step S19, and if it is determined that the split bright lines 311, 311 are zero, the process proceeds to step S21.

  In step S19, following the determination that the number of split bright lines 311 and 311 is one in step S18, it is determined whether or not the two alignment bright points 310 and 310 are located at a predetermined position, that is, inside the () scale 309. . If it is determined YES (alignment bright spot is within the specified position), the process proceeds to step S20, and if NO (alignment bright spot is outside the specified position), the process returns to step S3.

In step S20, following the determination in step S19 that the two alignment luminescent spots 310 and 310 are within the specified position, a small pupil stop (lens stop) is inserted, and the process proceeds to step S25.
That is, it is determined that the pupil is a small pupil because there is only one split bright line 311, 311 recognized in the observed image, and is automatically subject to the condition that the alignment of the allowable range is adjusted when determining the small pupil. Insert a small pupil stop (lens stop). For example, when the magnification is high (angle of view 30 °), the lens aperture is switched so that a pupil diameter of φ3.3 mm can be photographed. At the time of high magnification, the lens aperture is switched and an electric mask is inserted as a countermeasure for flare.

  In step S21, following the determination that the split bright lines 311 and 311 are zero in step S18, a small pupil stop (lens stop) is inserted as in step S20, and the process proceeds to step S22.

  In step S22, following the insertion of the small pupil stop in step S21, it is determined whether the photographing eye is the right eye or the left eye. If it is determined that the eye is the left eye, the process proceeds to step S23. If it is determined that the eye is the right eye, the process proceeds to step S24.

  In step S23, following the determination that the photographed eye in step S22 is the left eye, a guidance instruction to change the alignment is displayed to the examiner so that even one split bright line 311 or 311 enters in the left eye. The process proceeds to S3. Here, the guidance instruction is displayed by shifting the () scale 309 by 0.5 mm on the left eye of the subject.

  In step S24, following the determination that the imaging eye in step S22 is the right eye, a guidance instruction to change the alignment is displayed to the examiner so that even the split bright lines 311 and 311 can be entered with the right eye. The process proceeds to S3. Here, the guidance instruction is displayed by shifting the () scale 309 by an amount corresponding to 0.5 mm on the subject's right eye.

In step S25, following the determination that there are two split bright lines 311 and 311 in step S17, or the insertion of the small pupil stop in step S20, the difference between the center of gravity positions of the two alignment bright spots 310 and 310 is calculated, and the alignment is performed. The amount of motor movement by the motor 330 is determined, and the process proceeds to step S26.
Here, according to the positional relationship between the two alignment luminescent spots 310 and 310 with respect to the () scale 309, the motor movement direction (up / down / left / right / front / back) is determined together with the motor movement amount.

  In step S26, following the determination of the motor movement amount in step S25, the alignment motor 330 is driven with the determined motor movement amount and motor movement direction, and the process proceeds to step S27.

In step S27, following the driving of the alignment motor 330 in step S26, it is determined whether or not the two alignment bright spots 310 and 310 are matched in the () scale 309. If it is determined YES (alignment bright spots match), the process proceeds to step S28. If NO (alignment bright spots do not match), the process returns to step S16.
Here, the coincidence determination between the two alignment bright spots 310 and 310 is matched when, for example, the difference between the center of gravity positions of the two alignment bright spots 310 and 310 is 0.3 mm or less, or when the bright spot separation amount is within 1/6. Judge that

In step S28, following the determination that the alignment bright points 310 and 310 match in step S27, it is determined whether or not the final confirmation of the status of the split bright lines 311 and 311 has been completed. If it is determined YES (final confirmation of split bright lines 311, 311 is completed), the process proceeds to step S29. If NO (final confirmation of split bright lines 311, 311 cannot be confirmed), the process returns to step S3.
Here, the final confirmation of the split luminescent lines 311 and 311 is completed when the positions of the two split luminescent lines 311 and 311 are within the in-focus range, as in step S9, and the positions of the two split luminescent lines 311 and 311 are outside the in-focus range. Suppose that the final confirmation cannot be made.

  In step S29, following the determination that the final confirmation of the two split bright lines 311 and 311 has been completed in step S28, the shutter is automatically released while the xenon lamp 17a is turned on, and the fundus photographing operation is performed using the autoshoot function. Return to.

  FIG. 8 is a flowchart showing the flow of the alignment bright spot determination process executed in step S30 during the autofocus control operation executed by the board PC316 in the non-mydriatic fundus camera of the first embodiment (alignment target) Judgment processing part). Hereinafter, each step will be described.

  In step S301, the alignment LED 41 that generates the two alignment luminescent spots 310 and 310 is turned off, and the process proceeds to step S302.

  In step S302, following the extinction of the two alignment bright spots 310 and 310 in step S301, an observation video (dark image) from the CCD 37a of the observation CCD camera 37 is acquired, and the process proceeds to step S303.

  In step S303, following the acquisition of the unlit image in step S302, the acquired unlit image is stored, and the process proceeds to step S304 (background unlit image storage unit).

  In step S304, following the storage of the extinguished image acquired in step S303, or the determination of NO in step S312, or the determination of NO in step S316, or the determination of NO in step S317, The alignment LED 41 that generates the two alignment bright spots 310 and 310 is turned on, and the process proceeds to step S305.

  In step S305, following the lighting of the two alignment luminescent spots 310, 310 in step S304, or the determination of NO in step S307, an observation video (lighted image) is obtained from the CCD 37a of the observation CCD camera 37, The process proceeds to step S306.

  In step S306, following the acquisition of the lit image in step S305, the difference between the acquired lit image and the extinguished image stored in step S303 is taken, and the process proceeds to step S307.

In step S307, following the difference processing between the lit image and the unlit image in step S306, it is determined whether or not the first alignment bright spot candidate has been detected based on the luminance distribution characteristics of the difference image. If Yes (detection of first alignment bright spot candidate), the process proceeds to step S308, and if No (first alignment bright spot candidate is not detected), the process returns to step S305.
Steps S301 to S307 correspond to a first determination processing unit.

  In step S308, following the determination of the detection of the first alignment bright spot candidate in step S307, the alignment LED 41 that generates the two alignment bright spots 310 and 310 is turned off, and the process proceeds to step S309.

  In step S309, following the extinction of the two alignment bright spots 310 and 310 in step S308, an observation video (dark image) from the CCD 37a of the observation CCD camera 37 is acquired, and the process proceeds to step S310.

  In step S310, following the acquisition of the extinguished image in step S309, the difference between the acquired extinguished image and the extinguished image stored in step S303 is taken, and the process proceeds to step S311.

  In step S311, following the difference processing of the two unlit images in step S310, the unlit image acquired in step S309 is stored, and the process proceeds to step S312 (background unlit image storage unit).

In step S312, following the storage of the extinguished image in step S311, it is determined whether or not an alignment bright spot candidate has been detected based on the luminance distribution characteristics of the difference image between the two extinguished images. If Yes (non-detection of alignment bright spot candidate), the process proceeds to step S313. If No (detection of alignment bright spot candidate), the process returns to step S304.
Steps S308 to S312 correspond to a second determination processing unit.

  In step S313, following the determination that the alignment bright spot candidate is not detected in step S312, the alignment LED 41 that generates the two alignment bright spots 310 and 310 is turned on again, and the process proceeds to step S314.

  In step S314, following the lighting of the two alignment bright spots 310 and 310 in step S313, an observation video (lighted image) is obtained from the CCD 37a of the observation CCD camera 37, and the process proceeds to step S315.

  In step S315, following the acquisition of the lit image in step S314, the difference between the acquired lit image and the extinguished image stored in step S311 is taken, and the process proceeds to step S316.

  In step S316, following the difference process between the lit image and the unlit image in step S315, it is determined whether or not a second alignment bright spot candidate has been detected based on the luminance distribution characteristics of the difference image. If Yes (detection of second alignment bright spot candidate), the process proceeds to step S317. If No (second alignment bright spot candidate is not detected), the process returns to step S304.

  In step S317, following the detection determination of the second alignment bright spot candidate in step S316, it is determined whether or not the first alignment bright spot candidate in step S307 matches the second alignment bright spot candidate in step S316. to decide. If Yes (first alignment bright spot candidate and second alignment bright spot candidate match), the process proceeds to step S318. If No (first alignment bright spot candidate and second alignment bright spot candidate do not match), step is performed. Return to S304.

In step S318, following the determination that the first alignment bright spot candidate and the second alignment bright spot candidate match in step S317, the detected first alignment bright spot candidate or second alignment bright spot candidate is determined to be true. The alignment bright spots 310 and 310 are determined, and the process proceeds to step S16 in FIG.
Steps S313 to S318 correspond to a third determination processing unit.

Next, the operation will be described.
The actions of the non-mydriatic fundus camera of the first embodiment are “fundus photographing action by manual operation”, “autofocus action”, “alignment bright spot determination processing action”, “auto-shoot action when two split bright lines are recognized”, The explanation will be divided into “auto-shoot action at the time of small pupil determination” and “split bright line induction action”.

[Fundus photographing by manual operation]
FIG. 9 is a diagram for explaining the fundus photographing action by manual operation with the auto-ON / OFF switch turned off in the non-mydriatic fundus camera of the first embodiment. FIG. 9A is a monitor showing the eye to be examined in the center of the monitor. (B) shows the monitor screen before performing the focusing operation and alignment operation, (c) shows the monitor screen after performing the focusing operation and alignment operation, and (d) shows the screen during shooting. The monitor screen which displayed the review image of the fundus is shown. Hereinafter, for example, an operation procedure in the case where the examiner is an expert and performs fundus imaging by manual operation will be described.

  (1) When the power switch is turned on and the auto ON / OFF switch 213 is kept OFF, the observation screen is displayed after the opening title is displayed on the observation monitor 3b.

  (2) Pull the device body 3 to the front with the joystick 2b, and instruct the subject who has placed his chin on the chin rest 4 to look straight ahead.

  (3) The apparatus main body 3 is moved left and right and up and down with the joystick 2b, and the eye E to be examined is projected at the center of the observation monitor 3b as shown in FIG. 9 (a).

  (4) On the observation monitor 3b, align the () scale 309 with the subject's pupil and confirm that the size of the subject's pupil is larger than the () scale 309 as shown in FIG. To do. That is, it is confirmed whether fundus photography is possible.

  (5) When the apparatus main body 3 is pushed straight by the joystick 2b, two alignment bright spots 310, 310 for adjusting the working distance appear on the observation monitor 3b, so that the two alignment bright spots 310, 310 are shown in FIG. ) Match one as shown. At this time, the subject is instructed to see blinking green (internal fixation target).

  (6) By operating the focusing handle 3a, as shown in FIG. 9 (b), the two separated split luminescent lines 311 and 311 are aligned vertically as shown in FIG. 9 (c). Then, by operating the joystick 2b, as shown in FIG. 9C, the two alignment bright spots 310, 310 are put into the () scale 309.

  (7) When the match between the split bright lines 311 and 311 and the alignment bright spots 310 and 310 is confirmed and the photographing switch 2c provided at the upper end of the joystick 2b is pressed, the shutter is released while the xenon lamp 17a is emitted, and fundus photographing is performed. After shooting, a review image of the fundus at the time of shooting is displayed on the observation monitor 3b as shown in FIG.

  (8) When reviewing the fundus review image and performing the next shooting, press the shooting switch 2c again to return to the observation screen, so repeat the operations (2) to (7) to perform the next shooting. . If it is desired to delete an image after photographing the fundus, pressing the image deletion switch 207 on the review screen deletes the image and returns to the observation screen.

[Auto focus function]
FIG. 10 is a split bright line diagram for explaining the autofocus action during automatic fundus photographing with the auto-ON / OFF switch turned on in the non-mydriatic fundus camera of the first embodiment. FIG. 11 is an explanatory view of the center-of-gravity position detection operation of the split bright line in the autofocus operation at the time of automatic fundus photographing with the auto-ON / OFF switch turned on in the non-mydriatic fundus camera of the first embodiment. Hereinafter, for example, an autofocus operation procedure when the examiner is immature and the fundus imaging is performed in the auto imaging mode will be described.

  First, the auto focus operation in the auto shooting mode is not manually operated with respect to the focusing handle 3a, but by driving the auto focus motor 332, the two separated split bright lines 311 and 311 are vertically aligned as shown in FIG. Refers to movement.

  When the power switch is turned on and the auto ON / OFF switch 213 is turned ON to switch from anterior ocular segment imaging to fundus imaging, the process proceeds from step S1 to step S2 to step S3 to step S4 in the flowchart of FIG. In step S3, the fundus observation image from the CCD 37a of the observation CCD camera 37 is taken into the board PC 316 through the capture board 319 for one frame. In the next step S4, the position of the center of gravity of the split bright lines 311 and 311 for autofocus is detected.

  Here, detection of the position of the center of gravity of the split bright lines 311 and 311 will be described. As shown on the left side of FIG. 11, regions A1 and A2 having the same height as the split bright lines 311 and 311 in the captured fundus observation image and wider than the split bright lines 311 and 311 are set. Then, as shown on the right side of FIG. 11, the center point of the region where the luminance is equal to or higher than the threshold in the luminance distribution characteristics of the regions A1 and A2 is detected as the barycentric position.

  When it is determined that the number of the center of gravity positions of the split bright lines 311 and 311 detected is two, that is, the number of the split bright lines 311 and 311 is two, in the flowchart of FIG. 6, from step S4 to step S5 → It progresses to step S6-> step S7-> step S8-> step S9. In step S6, the difference between the center of gravity positions of the two split bright lines 311 and 311 is calculated (FIG. 11), and the motor movement amount by the autofocus motor 332 is determined. In step S7, the autofocus motor 332 is driven with the determined motor movement amount and motor movement direction. In step S8, the fundus observation image is again captured for one frame, and when the shift between the two split bright lines 311 and 311 is recognized, fine adjustment is performed using the autofocus motor 332 in the matching direction. In step S9, it is determined whether or not the positions of the two split bright lines 311 and 311 are within the focusing range.

  If it is determined in step S9 that it is within the in-focus range, the process proceeds from step S10 to step S11. In step S11, it is determined that the in-focus state has been completed, and the next small pupil detection operation or autoshoot function operation is started. To do. If it is determined in step S9 that it is out of focus range, the process returns to step S3, and the above autofocus operation is repeated until it is determined that it is within focus range.

  On the other hand, when it is determined that the number of the center of gravity positions of the split bright lines 311 and 311 detected is 1, that is, the number of the split bright lines 311 and 311 is determined to be one, in the flowchart of FIG. It progresses to S5-> step S12-> step S13-> step S14-> step S15. In step S12, it is determined whether the number of split bright lines 311 and 311 is one or zero. In step S13, the difference between the center of gravity position of one split bright line 311 and the preset focus position of the scanning line is calculated. In step S14, the autofocus motor 332 is driven by the movement amount and movement direction based on the determined difference. In step S15, the fundus observation image is again captured for one frame, and it is determined whether there are two split bright lines 311 and 311 recognized in the observation image.

  When it is determined that there are two split bright lines 311, 311 at the time of reaching step S15, the process proceeds to step S6, and the autofocus operation based on the two split bright lines 311, 311 is executed again. This is because the error is large in only one in-focus state. In step S15, it is checked again whether two split bright lines 311 and 311 exist. If two exist, the in-focus error is confirmed. A method (step S6 to step S8) for suppressing the above is executed.

  If it is determined in step S15 that there is only one split bright line 311, 311, the process proceeds to step S11, and the next small pupil detection operation or autoshoot function operation is performed based on the determination that the focusing is completed. To start.

[Alignment bright spot judgment processing action]
FIG. 12 is a diagram illustrating an example of a monitor image at the completion of focusing by the autofocus operation in the non-mydriatic fundus camera of the first embodiment. FIG. 13 is a time chart showing the blinking timing of the alignment LED 41 in the alignment bright spot determination process in the non-mydriatic fundus camera of the first embodiment. FIG. 14 is an explanatory diagram illustrating the difference processing operation between the lit image and the unlit image in the alignment bright spot determination process in the non-mydriatic fundus camera of the first embodiment.

  First, when the monitor image is viewed at the completion of focusing by the autofocus operation with the non-mydriatic fundus camera of the first embodiment, as shown in FIG. 12, the position away from the () scale 309 displayed at the center position of the screen The two alignment bright spots 310 and 310 existing in FIG. 3 and the two split bright lines 311 and 311 present at the same positions are displayed. In addition, the central ghost CG is projected in the () scale 309 in a shape very similar to the two alignment bright spots 310 and 310. The central ghost CG is generated when the halogen illumination light from the halogen lamp 17b of the illumination optical system 10 is reflected by the objective lens 11 and enters the observation optical system 30 or the photographing optical system 20.

  Thus, since the central ghost CG is reflected in the monitor image from the observation CCD camera 37 and the central ghost CG is very similar to the alignment bright spots 310 and 310, the central ghost CG is mistaken for the alignment bright spots 310 and 310. By detecting it, the auto alignment operation becomes a malfunction. In particular, in the non-mydriatic fundus camera having the automatic shooting mode as in the first embodiment, the auto-shoot operation function by the flash shooting operation works while the central ghost CG is erroneously detected as the alignment bright spots 310 and 310. End up. For this reason, the frequency of shooting mistakes increases, and the reliability and effectiveness of the automatic shooting mode is lost.

  On the other hand, in the non-mydriatic fundus camera of the first embodiment, the lighting acquired from the observation optical system 30 in the state where the alignment LED 41 included in the alignment system 40 is turned on by the alignment bright spot determination process of FIG. The difference between the image and the unlit image acquired from the observation optical system 30 in a state where the alignment LED 41 included in the alignment system 40 is unlit is obtained, and the alignment bright spot candidate detected by the luminance distribution characteristic of the difference image is used. The true alignment bright spots 310 and 310 recognized from the observation image are determined.

That is, when the process proceeds to step S30 following the focus completion determination in step S11, the alignment bright spots 310 and 310 are determined in step S30. In this alignment bright spot determination process, the process proceeds from step S301 to step S302, step S303, step S304, step S305, step S306, and step S307 as shown in the flowchart of FIG.
That is, in step S303, following the extinction of the alignment LED 41 in step S301 and the acquisition of the extinguishing image in step S302, the acquired extinguishing image is stored. In step S306, following the lighting of the alignment LED 41 in step S304 and the acquisition of the observation video (lighted image) in step S305, the difference between the acquired lighting image and the extinguished image stored in step S303 is calculated. Take. In step S307, it is determined whether or not the first alignment bright spot candidate has been detected based on the luminance distribution characteristics of the difference image.

  In step S307, when the first alignment bright spot candidate is not detected, the process returns to step S305, and a lit image is acquired again, and the process proceeds from step S306 to step S307. The determination as to whether a point candidate has been detected is repeated. Thereby, even when the lighting response of the alignment LED 41 is slightly delayed, the first alignment bright spot candidate can be reliably detected.

On the other hand, if it is determined in step S307 that the first alignment bright spot candidate has been detected, the process proceeds from step S308 to step S309 to step S310 to step S311 to step S312 as shown in the flowchart of FIG.
That is, in step S310, following the extinction of alignment LED 41 in step S308 and the acquisition of the observation video (dark image) in step S309, the difference between the acquired unlit image and the unlit image stored in step S303 is calculated. Take. In step S311, the extinguished image acquired in step S309 is stored, and in step S312, it is determined whether or not an alignment bright spot candidate has been detected based on the luminance distribution characteristics of the difference image between the two extinguished images.

  In step S312, if an alignment bright spot candidate is detected despite the difference processing between the unlit images, the alignment bright spot candidate is clearly not a true alignment bright spot, and the process returns to step S304. , Start again from the acquisition of the lighting image.

On the other hand, if no alignment bright spot candidate is detected in step S312, the first alignment bright spot candidate may be determined as the true alignment bright spot 310, 310. However, in the second determination process in steps S308 to S312 using the extinguished image, there is a possibility that bright spots from other light sources are included in the first alignment bright spot candidates. Therefore, if it is determined in step S312 that no bright spot candidate has been detected, as shown in the flowchart of FIG. 8, the process proceeds to step S313 → step S314 → step S315 → step S311 → step S316 → step S317 → step S318. Proceed with
That is, in step S315, following the relighting of the alignment LED 41 in step S313 and the acquisition of the observation video (lighted image) in step S314, the difference between the acquired lit image and the extinguished image stored in step S311. Take. In step S316, it is determined whether the second alignment bright spot candidate has been detected based on the luminance distribution characteristics of the difference image. Further, in step S317, it is determined whether or not the first alignment bright spot candidate in step S307 matches the second alignment bright spot candidate in step S316. In step S316, if the second alignment bright spot candidate is not detected, or if the first alignment bright spot candidate and the second alignment bright spot candidate do not match in step S317, the bright spot candidates are both Since it is not a true alignment bright spot, the process returns to step S304 and starts again from the acquisition of the first lighting image.

  On the other hand, if the second alignment bright spot candidate is detected in step S316 and it is determined in step S317 that the first alignment bright spot candidate and the second alignment bright spot candidate match, the process proceeds to step S318. The detected first alignment bright spot candidate or second alignment bright spot candidate is determined as the true alignment bright spot 310, 310.

  As described above, in the alignment bright spot determination process according to the first embodiment, the background extinction image that stores the background extinction image of the alignment evaluation range acquired from the observation optical system 30 in a state where the alignment LED 41 included in the alignment system 40 is extinguished. After storing the background extinguishing image after storing the storage unit (step S303, step S311), when obtaining a difference from the observation image for alignment bright spot determination, the background extinguishing image stored in the background extinguishing image storage unit Use. For this reason, as shown in FIG. 13, the blinking characteristic of the alignment LED 41 basically has only a short turn-off time (for example, 6 msec for two frames) twice, and the alignment LED 41 is turned on at other times. Can be maintained. Therefore, for example, the blinking frequency of the alignment LED 41 is reduced and the visual burden on the examiner can be reduced as compared with the case where the alignment LED 41 blinks every time the difference process is performed without using the stored image.

  Next, the reason why the difference between the lit image and the unlit image is removed, the influence of the central ghost CG is removed, and the luminance distribution characteristics based only on the alignment luminescent spots 310 and 310 can be acquired.

  First, a lighting image acquired from the observation optical system 30 in a state where the alignment LED 41 included in the alignment system 40 is lit, has a luminance distribution characteristic based on the alignment bright spots 310 and 310 and the central ghost CG, as shown in the upper characteristic of FIG. Become. On the other hand, the unlit image acquired from the observation optical system 30 in a state where the alignment LED 41 included in the alignment system 40 is unlit has a luminance distribution characteristic based only on the central ghost CG, as shown in the middle characteristic of FIG. Therefore, when the difference processing of both images is performed, the influence of the central ghost CG is removed as shown in the lower characteristic of FIG. 14, and a luminance distribution characteristic having two luminance peaks due to only the alignment bright spots 310 and 310 can be acquired. It depends on what you can do.

  Therefore, for example, as shown in FIG. 14, if the alignment bright spot determination threshold value is a threshold value A, the alignment bright spots 310 and 310 matching the central ghost CG are erroneously detected. If the alignment bright spot determination threshold is a threshold B, the central ghost CG and the alignment bright spots 310 and 310 are erroneously detected as three alignment bright spots. On the other hand, in the first embodiment, as described above, the alignment luminescent spots 310 and 310 are determined by the difference process between the lit image and the unlit image, and therefore, as shown in FIG. Assuming C, only the true alignment bright spots 310, 310 are determined as alignment bright spots.

[Auto-shoot action when recognizing two split lines]
FIG. 15 is a classification diagram of the alignment bright spot state at the time of automatic fundus photographing with the auto-on / off switch turned on in the non-mydriatic fundus camera of the first embodiment. (B) shows the state with only one bright spot in the scale (), (c) shows the state with two separate bright spots in the scale (d) ) Shows a state where there are two unmatched bright spots in the scale (), and (e) shows a state where there are two matched bright spots in the scale (). FIG. 16 is an explanatory diagram of the setting operation of the alignment bright spot detection region in the automatic alignment operation during automatic fundus photographing with the auto ON / OFF switch turned on in the non-mydriatic fundus camera of the first embodiment. FIG. 17 is an explanatory diagram of the function of detecting the center of gravity of the alignment bright spot in the auto-alignment operation at the time of automatic fundus photographing with the auto-ON / OFF switch turned on in the non-mydriatic fundus camera of the first embodiment. Hereinafter, an auto-shoot operation procedure when recognizing two split bright lines that is executed following the auto-focus operation will be described.

  First of all, auto-shooting in auto-shooting mode means auto-focusing and auto-alignment by motor drive control. When the focus condition and alignment-matching condition are confirmed, the flash is automatically emitted and the fundus is shot. This is the operation to perform.

  When it is determined that the focusing is completed in step S11 of FIG. 6 by the autofocus operation and the two split bright lines 311 and 311 are recognized, in the flowchart of FIG. 7, step S16 → step S17 → step S25 → step The process proceeds from S26 to step S27. In step S16, the gravity center positions of the two alignment bright spots 310 and 310 are detected. In step S17, it is determined whether or not the number of split bright lines 311 and 311 is one or less. In step S25, according to the determination that there are two split bright lines 311 and 311 in step S17, the difference between the center of gravity positions of the two alignment bright spots 310 and 310 is calculated, and the motor movement amount by the alignment motor 330 is determined. In step S26, alignment motor 330 is driven with the determined motor movement amount and motor movement direction. In step S27, it is determined whether or not the two alignment bright spots 310 and 310 match within the () scale 309.

  Here, the center-of-gravity position detection of the alignment bright spots 310 and 310 in step S16 will be described. First, as shown in FIG. 15, the positions of the alignment bright spots 310 and 310 are in a state where there is no bright spot in the scale 309 (FIG. 15A), and in a state where there is only one bright spot in the scale 309. (FIG. 15 (b)), () a state where there are two distant luminescent spots in the scale 309 (FIG. 15 (c)), and a state where there are two unmatched luminescent spots in the () scale 309 (see FIG. 15). 15 (d)), and () a state where there are two matched bright spots in the scale 309 (FIG. 15 (e)).

  As shown in FIG. 16, the detection areas of the alignment bright spots 310 and 310 include (A) an area A (area surrounded by the horizontal width a and the vertical width c) for detecting the alignment bright spots 310 and 310 in the scale 309, and ( When the alignment luminescent spots 310 and 310 are detected in the scale 309, the area divides into a region B (a region surrounded by the horizontal width b and the vertical width c) for detecting whether there are alignment luminescent spots 310 outside the scale 309. The area B is not used except when the alignment bright spots 310 and 310 are detected in the area A.

  As shown in FIG. 17, the method of detecting the alignment bright spots 310 and 310 divides the region A into four parts in the vertical direction by three horizontal lines. When the pixel values are accumulated in the vertical direction for each divided area, four waveforms are obtained. For the obtained waveform, the width of the portion that is greater than or equal to the set threshold is obtained. The longest width obtained for the four waveforms is defined as the width of the alignment bright spot 310. A range is provided for the calculated width, and if the width is within the range, the divided region is set as the position of the alignment bright spot 310. Only the portion of the divided area for which the maximum width is calculated is expanded to the area B shown in FIG. 16, and the alignment bright spot 310 is similarly detected. If the alignment bright spot 310 is not detected in the region B, the alignment bright spot 310 becomes one in the () scale 309, and it is considered that the two alignment bright spots 310 and 310 match.

  In step S25, the motor movement direction (up / down / left / right / front / rear) is determined together with the motor movement amount based on the positional relationship between the two alignment bright spots 310 and 310 with respect to the () scale 309. In step S26, alignment motor 330 is driven with the motor movement amount and motor movement direction determined in step S25. If it is determined in step S27 that the two alignment bright spots 310 and 310 do not match within the () scale 309, in the flowchart of FIG. 7, step S16 → step S17 → step S25 → step S26 → The flow of proceeding to step S27 is repeated.

  If it is determined in step S27 that the two alignment bright spots 310 and 310 match within the () scale 309, the process proceeds to step S28, and whether or not the final confirmation of the status of the split bright lines 311 and 311 has been completed. Determine whether. If it is determined in step S28 that the final confirmation of the split bright lines 311 and 311 has not been completed (two bright line positions are out of focus range), the process returns to step S3 and the autofocus operation is executed again.

  On the other hand, if it is determined in step S28 that the final confirmation of the split bright lines 311 and 311 has been completed (the two bright line positions are within the in-focus range), the process proceeds to step S29. In step S29, the xenon lamp 17a is automatically emitted. While releasing the shutter, perform the fundus photography using the auto-shoot function and return to the start.

  In other words, the auto-shoot function automatically detects the coincidence of the two alignment bright spots 310 and 310 and then automatically turns off the xenon lamp 17a without pressing the shooting switch 2c if the autofocus is finished and there is no blink. This is achieved by the action of photographing the fundus by closing the shutter while emitting light.

The auto-shoot operation is
1) Focus state Accuracy within ± 0.5D with auto focus
2) Alignment state It is assumed that the above conditions 1) and 2) are satisfied when the XY direction on the eye to be examined is within 0.5 mm and the Z direction on the eye to be examined is within 0.3 mm.

[Auto-shoot action when determining small pupils]
FIG. 18 is an explanatory diagram of a state in which two split bright lines are projected on the observation monitor 3b by the non-mydriatic fundus camera of Example 1, and (a) is an alignment bright spot when the pupil diameter of the eye E is 4 mm or more. (B) shows the incident light to the pupil when the pupil diameter of the eye E is 4 mm or more and the alignment luminescent spots match. FIG. 19 is an explanatory diagram showing a state in which only one split bright line is projected on the observation monitor 3b by the non-mydriatic fundus camera of the first embodiment. FIG. 19A shows an alignment bright when the pupil diameter of the eye E is within 4 mm. The monitor observation image when the points match is shown, and (b) shows the incident light to the pupil when the alignment bright points do not match. FIG. 20 is a diagram illustrating a fundus image for explaining the action of inserting a small pupil diaphragm (crystal diaphragm) and an electric mask when the small pupil is determined by the non-mydriatic fundus camera of the first embodiment.

  First, the small pupil photographing function in the auto photographing mode is an auto-shooting operation in which the fundus photographing is performed by automatically emitting a flash even when the eye E is a small pupil. This is a function that automatically turns the small pupil aperture.

  For example, when the eye E is a small pupil and only one split bright line 311 is displayed on the observation monitor 3b, in the flowchart of FIG. 7, from step S17 to step S18 → step S19 → step S20. move on. In step S18, it is determined whether the split bright lines 311 and 311 recognized in the observation image are one or zero. In step S19, following the determination that the number of split bright lines 311 and 311 is one in step S18, it is determined whether or not the two alignment bright points 310 and 310 are located at a predetermined position, that is, inside the () scale 309. . In step S20, following the determination in step S19 that the two alignment bright spots 310 and 310 are within the specified position, a small pupil stop (lens stop) is inserted.

  That is, when the pupil diameter of the eye E is 4 mm or more and the alignment bright spots 310 and 310 match, as shown in FIG. 18B, the alignment bright spots 310 and 310 are formed after passing through the pupil of the eye E. Two lights are incident. Therefore, as shown in FIG. 18A, two split bright lines 311 and 311 are displayed on the observation monitor 3b.

  On the other hand, the two alignment bright spots 310 and 310 coincide with each other, but when the pupil diameter of the eye E is 4 mm or less, the alignment bright spots 310 and 310 are formed after passing through the pupil of the eye E. Since two lights cannot be incident simultaneously, only one split bright line 311 is displayed on the observation monitor 3b as shown in FIG. If the alignment bright spots 310 and 310 do not match regardless of the pupil diameter of the eye E, the alignment bright spot 310 is formed after passing through the pupil of the eye E as shown in FIG. Since only one light is incident, as shown in FIG. 19A, only one split bright line 311 is projected on the observation monitor 3b.

  Therefore, when both the split bright line condition in which only one split bright line 311 is displayed on the observation monitor 3b and the alignment bright spot matching condition in which the two alignment bright spots 310 and 310 match are satisfied, the eye E It can be determined that the pupil diameter is a small pupil within 4 mm.

  As described above, when it is determined that the pupil is a small pupil, if the amount of light is determined based on the pupil diameter being 4 mm or more, the incident light to the fundus is too strong, causing flare and the like. The fundus image cannot be taken. For this reason, a sharp pupil image can be captured by automatically inserting a small pupil diaphragm (crystal diaphragm) that is squeezed so as to suppress the amount of light reaching the fundus.

  For example, by switching the lens aperture at high magnification (angle of view 30 °), it is possible to photograph up to a pupil diameter of φ3.3 mm. At the time of high magnification, the lens aperture is switched and, as a countermeasure against flare, as shown in FIG. 16, an electric mask at the time of high magnification is put in a range indicated by a thick solid line ring. Note that FIG. 16 shows an electric mask in a high magnification ratio together with a rectangular high-magnification shooting range and an electric mask in a range indicated by a thin line ring at an angle of view of 45 °.

  Then, after inserting the small pupil stop in step S20, the process proceeds from step S25 to step S26 to step S27, and even if the eye E is a small pupil, even if the photographing switch 2c is not pressed, it is automatically performed. An auto-shoot function is achieved in which the xenon lamp 17a emits light and the shutter is released to perform fundus photography.

[Split emission line induction effect]
For example, when the eye E is a small pupil and no split bright line is projected on the observation monitor 3b, the autofocus operation performed using at least one split bright line 311 cannot be executed. The shooting function is not demonstrated.

  Therefore, when the eye E is a small pupil and no split bright line is projected on the observation monitor 3b, the process proceeds from step S17 to step S18 to step S21 in the flowchart of FIG. In step S21, following the determination that the split bright lines 311 and 311 are zero in step S18, a small pupil stop (lens stop) is inserted as in step S20. That is, when no split bright line is displayed on the observation monitor 3b, it can be estimated that the pupil diameter of the eye E is within 4 mm, so that the small pupil aperture is the same as in the small pupil determination. Insert the lens diaphragm.

  In the next step S22, it is determined whether the photographed eye is the right eye or the left eye. If it is determined that the photographing eye is the left eye, the process proceeds to step S23, and even one split bright line 311 or 311 enters in the left eye. In this way, a guidance instruction is displayed to the subject, and the process proceeds to step S3. Here, the guidance instruction is displayed by shifting the () scale 309 by 0.5 mm on the left eye of the subject.

  If it is determined that the eye is the right eye, the process proceeds to step S24, and a guidance instruction to change the alignment is displayed to the examiner so that at least one split bright line 311 or 311 can be entered by the right eye, and the process proceeds to step S3. . Here, the guidance instruction is displayed by shifting the () scale 309 by an amount corresponding to 0.5 mm on the subject's right eye.

  Accordingly, even when the eye E is a small pupil and no split bright line is displayed on the observation monitor 3b, at least one split bright line 311 is displayed on the observation monitor 3b by the split bright line guiding operation. A guidance instruction to change the alignment is given to the examiner. For this reason, when performing fundus imaging in the auto imaging mode, the examiner who sees the deviation of the () scale 309 corrects and changes the alignment so that the alignment with respect to the subject becomes the normal position, so that at least one split emission line 311 is obtained. Is displayed on the observation monitor 3b, the execution of the autofocus operation performed using one or two split bright lines 311 and 311 is ensured, and the autoshoot function intended by the examiner can be exhibited.

Next, the effect will be described.
In the non-mydriatic fundus camera of the first embodiment, the effects listed below can be obtained.

  (1) As an optical system, an illumination optical system 10 for illuminating the fundus oculi Ef of the eye E to be examined, an alignment system 40 for projecting alignment bright spots 310 and 310 for aligning the apparatus main body 3 with respect to the eye E to be examined, The non-mydriatic fundus camera includes an observation optical system 30 including an observation CCD camera 37 that adds the alignment bright points 310 and 310 to the fundus image of the eye E to be observed to form an observation video signal. A difference between a lighting image acquired from the observation optical system 30 with the alignment LED 41 turned on and a light-off image acquired from the observation optical system 30 with the alignment LED 41 included in the alignment system 40 turned off is obtained. The alignment target candidates detected based on the luminance distribution characteristics of the difference image are determined as true alignment bright spots 310 and 310 recognized by the observation image. Raimento target determination processing unit having a (step S30, FIG. 8). For this reason, during the alignment operation, it is possible to reliably avoid erroneous operation of the alignment operation due to erroneous recognition or erroneous detection of the central ghost CG as an alignment target.

  (2) As an operation control system, the observation video signal of the fundus portion is taken from the observation optical system 30 and the apparatus main body 3 is attached to the eye E based on the position detection of the alignment bright spots 310 and 310 recognized by the observation image. An auto-alignment operation control unit that performs an auto-alignment operation for alignment is performed, and the alignment target determination processing unit (step S30, FIG. 8) uses a difference image between the lit image and the unlit image prior to the auto-alignment operation. The alignment alignment points 310 and 310 are determined, and the auto-alignment operation control unit performs an auto-alignment operation for aligning the apparatus main body with respect to the eye to be inspected based on the position detection of the determined alignment bright points 310 and 310. For this reason, in the automatic alignment operation control, erroneous operation of the automatic alignment operation due to erroneous detection of the central ghost CG as an alignment target can be reliably avoided.

  (3) The alignment target determination processing unit (step S30, FIG. 8) displays a background extinction image of the alignment evaluation range acquired from the observation optical system 30 in a state where the alignment LED 41 included in the alignment system 40 is extinguished. When the background extinguished image storage unit (step S303, step S311) is stored and the background extinguished image is stored and then the difference from the observation image is obtained for alignment target determination, the background extinguished image storage unit (step The background extinguishing image stored in S303 and step S311) is used. For this reason, for example, compared with the case where the alignment LED 41 is blinked every time the difference process is performed without using the stored image, the blink frequency of the alignment LED 41 is reduced, and the visual burden on the examiner can be reduced.

  (4) The alignment target determination processing unit (step S30, FIG. 8) turns off the alignment LED 41 (step S301), acquires the observation video from the observation CCD camera 37 (step S302), and acquires the acquired extinction The image is stored (step S303), then the alignment LED 41 is turned on (step S304), the observation video from the observation CCD camera 37 is acquired (step S305), and the acquired lighting image and the stored extinguishing light are stored. A first determination processing unit (steps S301 to S307) that takes the difference from the image (step S306) and uses the alignment bright spots 310 and 310 detected by the luminance distribution characteristics of the difference image as alignment target candidates; When the alignment target candidate is detected by the determination processing unit (steps S301 to S307), the alignment LED 41 is turned off (step S308), and the observation CCD camera is turned off. The observation video from the camera 37 is acquired (step S309), and the difference between the acquired unlit image and the unlit image stored in the first determination processing unit (step S303) is obtained (step S310). If the alignment target candidate is not detected based on the luminance distribution characteristic of the image, the second determination process for determining the alignment target candidate detected by the first determination processing unit (steps S301 to S307) as a true alignment target. (Step S308 to step S312). For this reason, when the stored unlit image includes a bright spot other than the central ghost CG, erroneous determination of the alignment bright spots 310 and 310 can be prevented.

  (5) The alignment target determination processing unit (step S30, FIG. 8) turns off the alignment LED 41 (step S301), acquires the observation video from the observation CCD camera 37 (step S302), and acquires the acquired extinction The image is stored (step S303), then the alignment LED 41 is turned on (step S304), the observation video from the observation CCD camera 37 is acquired (step S305), and the acquired lighting image and the stored extinguishing light are stored. A first determination processing unit (step S301 to step S307) that takes a difference from the image (step S306) and determines whether or not a first alignment target candidate is detected based on the luminance distribution characteristic of the difference image; When the first alignment target candidate is detected by the 1 determination processing unit (step S301 to step S307), the alignment LED 41 is turned off and the observation image from the observation CCD camera 37 is displayed. Is acquired (step S308), the difference between the acquired extinguishing image and the extinguishing image stored in the first determination processing unit (step S303) is taken, and the acquired extinguishing image is stored (step S311), In a second determination processing unit (step S308 to step S312) for determining whether or not an alignment target candidate has not been detected based on the luminance distribution characteristic of the difference image, and the second determination processing unit (step S308 to step S312) If the alignment target candidate is not detected, the alignment LED 41 is turned on (step S313), the observation video from the observation CCD camera 37 is acquired (step S314), the acquired lighting video and the second determination processing unit ( The difference from the extinguished image stored in step S311) is taken (step S315), and the alignment target detected by the luminance distribution characteristic of the difference image is used as the second alignment. If the first alignment target candidate matches the second alignment target candidate (Yes in step S317), the detected alignment target candidate is set as a true alignment target. A third determination processing unit (steps S313 to S318) for determination. Therefore, not only when the bright image other than the central ghost CG is included in the stored unlit image, but also when the bright image other than the alignment bright points 310, 310 is included in the acquired illuminated image. Thus, erroneous determination of the alignment bright spots 310 and 310 can be prevented reliably.

  (6) As the optical system, a split optical system 60 for projecting split bright lines 311 and 311 for focusing on the fundus oculi Ef portion of the eye E to be examined; a fundus image of the eye E to be examined; the split bright lines 311 and 311 and the alignment bright points 310 and 310 And an observation optical system 30 including an observation CCD camera for use as an observation video signal, and a photographing optical system 20 including a photographing CCD camera 6 for photographing a fundus image of the eye E to be examined. Based on the position recognition of the split bright lines 311 and 311 displayed on the observation optical system 30 together with the imaging target portion, a focusing operation for focusing on the imaging target portion of the eye E is displayed on the observation optical system 30 together with the imaging target portion. Based on the position recognition of the alignment bright spots 310 and 310, an alignment operation for aligning the apparatus main body 3 with respect to the eye E is performed, and a final confirmation result of focusing and alignment is performed. When is within the proper range, it provided the automatic photographing control means for performing automatic flash photographing operation (FIG. 6, FIG. 7). For this reason, it is possible to reduce imaging errors due to the automatic flash imaging operation being performed with the alignment position shifted due to erroneous detection of the alignment bright spots 310 and 310.

  (7) The automatic photographing control means (FIG. 6 and FIG. 7) is configured so that the split target condition that there is one split bright line 311 recognized by the observation video signal of the observation optical system 30 (one case in step S18). ) And the alignment matching condition (YES in step S19) that the two alignment luminescent spots 310 and 310 are within the prescribed range are both determined to be that the eye E is a small pupil and before the automatic flash photographing operation is performed. And a small pupil diaphragm insertion control unit (step S20) for automatically inserting a small pupil diaphragm. For this reason, even if the subject is a small pupil, the subject with the small pupil can be included in the subject of automatic imaging by automatically inserting the small pupil stop.

  As mentioned above, although the ophthalmologic apparatus of this invention has been demonstrated based on Example 1, about a concrete structure, it is not restricted to this Example 1, The summary of the invention which concerns on each claim of a claim is included. Unless it deviates, design changes and additions are allowed.

  In the first embodiment, an example in which a true alignment target is determined during auto alignment operation control as the alignment target determination processing unit has been described. However, the alignment target determination processing unit may determine a true alignment target during an alignment operation by manual operation. In this case, a display that can confirm the determined position of the true alignment target on the monitor screen is also performed.

  In the first embodiment, two square split bright lines 311 and 311 are used as split targets, and the state in which the two split bright lines 311 and 311 are aligned in the vertical direction is shown as an in-focus state. However, the split target may have various shapes other than a square. Furthermore, an example in which a state in which a plurality of split targets are aligned in the horizontal direction may be an in-focus state.

  In the first embodiment, two circular alignment bright spots 310 and 310 are used as alignment targets, and the state in which the two alignment bright spots 310 and 310 are aligned with the center position of the () scale 309 is shown as an alignment adjustment state. . However, the alignment target may have various shapes other than a circular shape. Further, an example in which the alignment adjustment state is a state in which a plurality of alignment targets are matched with the outer peripheral position of the scale display having a shape other than () scale 309 may be used.

  In the first embodiment, the example in which the auto focus operation control is preceded and the auto alignment operation control is subsequently performed is shown. However, an example in which auto-alignment operation control is preceded and then auto-focus operation control is performed may be used. Furthermore, an example in which auto alignment operation control and auto focus operation control are performed by automatic photographing control by simultaneous progress may be used.

  In the first embodiment, the application example to the non-mydriatic retinal camera which is an example of the ophthalmologic apparatus in which the focusing operation and the alignment adjustment operation are automated is shown. However, at least one of the focusing operation and the alignment adjustment operation is automated. The present invention can also be applied to an ophthalmologic apparatus and an ophthalmologic apparatus in which focusing operation and alignment adjustment operation are manual.

1 is an overall system diagram illustrating a non-mydriatic fundus camera (an example of an ophthalmologic apparatus) according to a first embodiment. FIG. 3 is a plan view showing an operation panel set in a gantry in the non-mydriatic retinal camera of Example 1. It is an image figure which shows each display content displayed on the observation monitor set to the apparatus main body in the non-mydriatic retinal camera of Example 1. FIG. FIG. 3 is an optical arrangement diagram showing an optical system built in the apparatus main body 3 in the non-mydriatic retinal camera of Example 1. FIG. 3 is an electric block diagram illustrating a control system built in the apparatus base 1, the gantry unit 2, and the apparatus body 3 in the non-mydriatic fundus camera of the first embodiment. 6 is a flowchart illustrating a flow of an autofocus control operation executed by a board PC316 in the non-mydriatic fundus camera of the first embodiment. 6 is a flowchart showing a flow of an autoshoot control operation (including repetition of a flow of an autofocus control operation) executed by the board PC 316 in the non-mydriatic fundus camera of the first embodiment. 6 is a flowchart showing a flow of alignment bright spot determination processing executed in step S30 during the autofocus control operation executed by the board PC316 in the non-mydriatic fundus camera of the first embodiment. It is a figure explaining the fundus imaging action by the manual operation with the auto-ON / OFF switch turned off in the non-mydriatic fundus camera of Example 1, (a) shows a monitor screen showing the eye to be examined in the center of the monitor, (b) shows the monitor screen before performing the focusing operation and alignment operation, (c) shows the monitor screen after performing the focusing operation and alignment operation, and (d) shows the review image of the fundus at the time of shooting. A monitor screen displaying is displayed. FIG. 6 is a split bright line diagram illustrating an autofocus action during automatic fundus photographing with the auto-ON / OFF switch turned on in the non-mydriatic fundus camera of Example 1; It is explanatory drawing of the gravity center position detection effect | action of a split bright line in the autofocus operation | movement at the time of the automatic fundus imaging | photography with the auto ON / OFF switch set to ON by the non-mydriatic fundus camera of Example 1. FIG. 6 is a diagram illustrating an example of a monitor image at the completion of focusing by an autofocus operation in the non-mydriatic retinal camera of the first embodiment. 6 is a time chart showing the blinking timing of the alignment LED 41 in the alignment bright spot determination process in the non-mydriatic fundus camera of the first embodiment. It is explanatory drawing which shows the difference process effect | action of the lighting image in the alignment bright spot determination process in the non-mydriatic fundus camera of Example 1, and a light extinction image. It is a classification diagram of the alignment bright spot state at the time of automatic fundus photographing with the auto ON / OFF switch turned on in the non-mydriatic fundus camera of Example 1, (a) is a state where there is no bright spot in the () scale (B) shows the state where there is only one bright spot in the () scale, (c) shows the state where there are two separate bright spots in the () scale, and (d) shows the state () A state where there are two unmatched bright spots in the scale is shown, and (e) shows a state where there are two matched bright spots in the scale (). FIG. 6 is an explanatory diagram of an operation for setting an alignment bright spot detection region in an auto-alignment operation at the time of automatic fundus photographing with the auto-ON / OFF switch turned on in the non-mydriatic fundus camera of Example 1; It is explanatory drawing of the gravity center position detection effect | action of the alignment bright spot in the auto-alignment operation | movement at the time of automatic fundus imaging | photography with the auto ON / OFF switch set to ON by the non-mydriatic fundus camera of Example 1. It is explanatory drawing of the state by which two split bright lines are projected on the observation monitor 3b with the non-mydriatic fundus camera of Example 1, (a) is that the pupil diameter of the eye E is 4 mm or more, and the alignment bright spot matches. (B) shows the incident light of the pupil when the pupil diameter of the eye E is 4 mm or more and the alignment bright spot is matched. It is explanatory drawing of the state by which only one split bright line is projected on the observation monitor 3b with the non-mydriatic fundus camera of Example 1, (a) is the pupil diameter of the eye E within 4 mm, and the alignment bright spot matches. (B) shows pupil incident light when alignment bright spots do not match. It is a figure which shows the fundus image for demonstrating the insertion effect | action of a small pupil aperture (crystal aperture) and an electric mask at the time of a small pupil determination with the non-mydriatic fundus camera of Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Device base 2 Base part 2a Operation panel 2b Joystick 2c Shooting switch
209 Pupil switch
213 Auto ON / OFF switch 3 Main unit 3a Focusing handle 3b Observation monitor 31 Observation LCD unit 37 CCD camera for observation (observation camera)
309 () scale
310,310 Alignment bright spot (alignment target)
311,311 Split line (split target)
313 Small pupil diaphragm
315 PCB
316 board PC
317 Shooting Camera Relay PCB
318 DC power PCB
319 capture board
324 Alignment motor detection sensor
326 Autofocus motor (+) detection sensor
327 Autofocus motor (-) detection sensor
330 Alignment motor (alignment actuator)
332 Autofocus motor (Autofocus actuator)
333 Lens drive solenoid
334 Anterior segment switching drive solenoid
335 Reflector drive solenoid 4 Chin rest 5 External fixation target 6 CCD camera for photography (camera)
7 mouse / 10 keyboard 8 printer 9 personal computer 9a PC monitor 10 illumination optical system 17a xenon lamp 17b halogen lamp 20 imaging optical system 30 observation optical system 40 alignment system 41 alignment LED (alignment light source)
50 Internal fixation system 60 Split optical system 61 Split LED
E Eye to be examined
Ef fundus (target)

Claims (6)

As an optical system, an illumination optical system for illuminating the imaging target of the eye to be examined, an alignment system for projecting an alignment target for aligning the apparatus main body with respect to the eye to be examined, and the imaging target image of the eye to be examined are described above. In an ophthalmologic apparatus comprising an observation optical system including an observation camera that adds an alignment target and forms an observation video signal,
A difference between a lighting image acquired from the observation optical system with the alignment light source included in the alignment system turned on and a light-off image acquired from the observation optical system with the alignment light source included in the alignment system turned off. look, have a alignment target candidates detected by the luminance distribution characteristics of said difference image, determining alignment target determination processing unit and the true alignment target recognized by the observation image,
The alignment target determination processing unit includes a background extinguishing image storage unit that stores a background extinguishing image of an alignment evaluation range acquired from the observation optical system in a state where an alignment light source included in the alignment system is extinguished. An ophthalmic apparatus characterized by using a background unlit image stored in the background unlit image storage unit when a difference from an observed image is obtained for alignment target determination after storing the unlit image . The ophthalmic device according to claim 1,
The alignment target determination processing unit
Turn off the alignment light source, acquire the observation video from the observation camera, store the acquired extinguishing image, then turn on the alignment light source, acquire the observation video from the observation camera, and acquire the lighting image A first determination processing unit that takes an alignment target detected by the luminance distribution characteristic of the difference image as an alignment target candidate,
When the alignment target candidate is detected by the first determination processing unit, the alignment light source is turned off, the observation video from the observation camera is acquired, and the acquired unlit image and the first determination processing unit are stored. If a difference from the previously-off image is taken and no alignment target candidate is detected based on the luminance distribution characteristic of the difference image, the alignment target candidate detected by the first determination processing unit is determined as a true alignment target. A second determination processing unit for determining;
An ophthalmologic apparatus comprising: The ophthalmic device according to claim 2 ,
The alignment target determination processing unit
Turn off the alignment light source, acquire the observation video from the observation camera, store the acquired extinguishing image, then turn on the alignment light source, acquire the observation video from the observation camera, and acquire the lighting image And a first determination processing unit that determines whether or not the first alignment target candidate has been detected based on the luminance distribution characteristics of the difference image,
When the first alignment target candidate is detected by the first determination processing unit, the alignment light source is turned off, the observation video from the observation camera is acquired, and the acquired turn-off image and the first determination processing unit A second determination processing unit that takes a difference from the stored unlit image and stores the acquired unlit image and determines whether or not an alignment target candidate has been detected based on the luminance distribution characteristics of the difference image;
If the alignment target candidate is not detected by the second determination processing unit, the alignment light source is turned on, an observation video from the observation camera is acquired, and the acquired lighting video and the second determination processing unit are stored. Taking the difference from the extinguished image, the alignment target detected by the luminance distribution characteristic of the difference image is set as the second alignment target candidate, and the first alignment target candidate and the second alignment target candidate A third determination processing unit that determines the detected alignment target candidate as a true alignment target if
An ophthalmologic apparatus comprising: In the ophthalmologic apparatus according to any one of claims 1 to 3,
As the optical system, a split optical system for projecting a split target for focusing on a photographing target portion of the eye to be examined, and a photographing target image of the eye to be examined as an observation video signal together with the split target and the alignment target. An observation optical system including an observation camera, and an imaging optical system including a camera that captures an imaging target image of the eye to be examined,
As the operation control system, based on the position recognition of the split target displayed on the observation optical system together with the photographing target portion, a focusing operation for focusing on the photographing target portion of the eye to be examined, and the observation optical system together with the photographing target portion. Based on the position recognition of the displayed alignment target, an alignment operation is performed to align the device body with the eye to be examined, and an automatic flash shooting operation is performed when the final confirmation result of focusing and alignment is within the appropriate range. An ophthalmologic apparatus characterized in that automatic photographing control means is provided. The ophthalmic device according to claim 4,
The automatic photographing control means includes a split target condition that one split target is recognized by an observation video signal of the observation optical system and an alignment matching condition that two alignment targets are within a specified range. If both are established, the ophthalmologic apparatus has a small pupil stop insertion control unit that determines that the eye to be examined is a small pupil and automatically inserts the small pupil stop before performing the automatic flash photographing operation. In the ophthalmologic apparatus according to any one of claims 1 to 5,
As an operation control system, an auto-alignment operation that takes in an observation video signal of a photographing target portion from the observation optical system and aligns the apparatus main body with respect to the eye to be inspected based on the position detection of the alignment target recognized by the observation image Has an auto alignment operation control unit
The alignment target determination processing unit determines a true alignment target based on a difference image between a lit image and an unlit image prior to the auto alignment operation,
The auto-alignment operation control unit performs an auto-alignment operation of aligning the apparatus main body with respect to the eye to be examined based on the position detection of the determined alignment target.

Images