JP2013215624A - Fundus camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform origin calibration of an optical member without hindering observation and photographing.SOLUTION: When switching of right and left eyes is detected in steps S1-S8 using a right/left eye detecting switch, a focus lens is moved toward the origin position of a lens detecting part in a step S9. When the focus lens is detected in a step S10, an advance to a step S11 is made. To calibrate the origin position of the focus lens, the count value of a pulse counter of the lens detecting part is set to 0.

Description

The present invention relates to a fundus camera used in an ophthalmic clinic or the like.

  With the recent progress of digitization, opportunities to digitally control the position control of the optical member of the fundus camera are increasing. One of the advantages of digital control is that the complex mechanism is simplified, and even if the illumination wavelengths for observation and photographing are different, the positioning control of the optical member corresponding to each can be performed.

  However, it is known that when the actuator for positioning the optical member is open loop control, a phenomenon in which the electrical position information and the absolute position are gradually shifted occurs. This deviation means a deviation from the optical origin, and becomes a problem related to the image quality of the photographed image. In order to solve this problem, various methods such as Patent Document 1 have been proposed.

JP 2004-16486 A

However, if the origin calibration of the optical member is performed during observation or photographing as in Patent Document 1, there may be a problem in diagnosis.
An object of the present invention is to provide a fundus camera capable of correcting the origin of an optical member without obstructing the above-described problems and observing and photographing.

  In order to achieve the above object, a fundus camera according to the present invention comprises an interface means for commanding operation, a position control means for controlling the position of an optical member disposed in an observation photographing optical path to function its optical characteristics, and the optical Detection means for detecting the origin position of the member, calibration means for calibrating the origin position of the optical member based on the output of the detection means, imaging means for photographing the fundus through the optical member, and interface means A control means for operating the detection means and the calibration means is provided between operations according to commands.

  According to the fundus camera of the present invention, it is possible to calibrate the origin of the optical member in a state that does not hinder the examiner's observation and photographing. Further, since the origin calibration of the optical member is performed at a time peculiar to the fundus camera, the origin calibration can be performed without any trouble in observation and photographing.

It is a block diagram of a fundus camera. It is an external view of a fundus camera. It is an operation | movement flowchart figure at the time of right-and-left eye switching detection. It is an operation | movement flowchart figure which switches an observation site | part. It is an operation | movement flowchart figure when an imaging | photography button is selected. It is a flowchart figure of the origin search of a focus lens. It is a flowchart figure at the time of switching imaging | photography mode.

  The present invention will be described in detail based on the embodiments shown in the drawings.

  FIG. 1 shows a configuration diagram of a fundus camera in the present embodiment. In the housing, an illumination optical path O1 is provided from the observation light source 1 to the objective lens 2 arranged to face the eye E to be examined. In this illumination optical path O1, an observation light source 1 composed of a halogen lamp that emits visible light, an imaging light source 3 composed of a xenon lamp that emits visible light, a visible ring slit 4, and an illumination mirror 5 are sequentially arranged. Behind the illumination mirror 5, an infrared ring slit 6 and an infrared LED 7 which is a light source for performing infrared light observation are arranged. The illumination mirror 5 is composed of a dichroic mirror, and has a characteristic of reflecting visible light and transmitting infrared light. The illumination mirror 5 can synthesize optical paths of visible ring illumination and infrared ring illumination. It has become.

  Further, in the reflection direction of the illumination mirror 5, the illumination relay lens 8, the optical filter unit 9 that can be inserted into and removed from the optical path, the split unit 10, the illumination relay lens 11, the perforated mirror 12, and the anterior eye observation that can be inserted into and removed from the optical path. Lenses 13 are sequentially arranged.

  The optical filter unit 9 can be inserted into and removed from the illumination optical path O1, and has filters 9a to 9d having different optical characteristics, and the filters 9a to 9d can be switched according to the photographing mode. Yes. The split unit 10 includes light sources 10a and 10b for projecting a focus index, and a prism 10c for splitting a light beam. The split unit 10 is inserted into the illumination optical path O1 during fundus observation and projects the focus index onto the eye E.

  Behind the perforated mirror 12, a focus lens 14, which is an optical member movable in the optical axis direction, a movable mirror 15, and an image sensor 16 are sequentially arranged. Further, a finder eyepiece 18 is disposed in the reflection direction of the movable mirror 15 via a fixed mirror 17.

  This fundus camera incorporates a system control unit 21 that performs system control, data processing, and the like of the entire fundus camera. The output of the image sensor 16 is connected to the system control unit 21, and the output of the observation light source 1 and the observation light source selection switch 22 for selecting the infrared LED 7 is also connected. Further, the system control unit 21 detects detection information of position information of the optical filter unit 9, the split unit 10, the anterior eye observation lens 13, the focus lens 14, and the focus adjustment knob 28 via detection units 23 to 27 serving as detection means. Is connected. The output of the system control unit 21 is connected to the optical filter unit 9, the split unit 10, the anterior eye observation lens 13, and the focus lens 14 via driving units 29 to 32 as position control means.

  The system control unit 21 supplies power to the imaging light source 3 via the capacitor 33. The amount of charge stored in the capacitor 33 differs depending on the imaging mode described later, and the system control unit 21 changes when the imaging mode is changed. Then, charging / discharging with an appropriate charge amount is performed. Further, when the system control unit 21 determines that the observation is not performed within a predetermined time, the observation light source 1 and the infrared LED 7 are turned off.

  The optical filter unit 9 is inserted into and removed from the illumination optical path O1 by the drive unit 29, and the detection unit 23 detects the insertion and removal. By inserting the anterior eye observation lens 13 into the photographing optical path O2, the anterior eye of the eye E can be observed, and when the anterior eye observation lens 13 is not inserted, the fundus can be observed. The insertion / removal of the anterior eye observation lens 13 to / from the photographing optical path O2 is performed by the drive unit 31, and the insertion / removal is detected by the detection unit 25. These switching operations are controlled by the system control unit 21 on the basis of input information from interface means described later.

  The focus lens 14 adjusts the focus, which is a function of its optical characteristics, by moving it in the direction of the arrow by the lens drive unit 32 with respect to the photographic light beam that has passed through the central hole of the perforated mirror 12, and the lens detection unit 26 performs focus adjustment. The position of the lens 14 is detected. The focus lens 14 is moved by the drive pulse, and the lens detection unit 26 can detect the position of the focus lens 14 by counting the drive pulse by the pulse counter of the lens detection unit 26.

  The movable mirror 15 is inserted into the photographing optical path O2 during visual observation by the observation light source 1, guides the photographing light to the observation optical path O3, and the examiner observes the fundus image through the fixed mirror 17 and the viewfinder eyepiece 18. Further, during infrared light observation with the infrared LED 7 and when photographing with the photographing light source 3, it is retracted above the photographing optical path O2 by rotating as indicated by an arrow.

  FIG. 2 shows an external view of the fundus camera. On the stage base portion 41, a stage portion 42 that can be freely moved within a predetermined stroke in the XY direction is placed. Various interface means for commanding the operation of the camera are arranged. Inside the stage unit 42, left and right eye detection switches (not shown) are provided for determining the left and right eyes by moving the stage unit 42 left and right. A head unit 44 incorporating the optical system of the fundus camera shown in FIG. 1 is attached on the stage unit 42 via a hinge unit 43.

  On the stage unit 42, a joystick unit 45 for moving the stage unit 42 in the XY direction, an observation region switching button 46 for switching the observation region, an imaging mode switching button 47 for switching the imaging mode, and an observation light source selection switch 22 are provided. It has been. A shooting button 48 is provided at the tip of the joystick portion 45. A focus adjustment knob 28 is provided on the side surface of the head unit 44, and a monitor unit 49 on which a fundus image is displayed during infrared light observation is disposed on the back surface of the head unit 44.

  In the fundus camera of the present embodiment, five shooting modes of COLOR / RED FREE / COBALT / FLUO / self-fluorescent shooting (FAF) can be selected by the shooting mode switching button 47.

  At the time of fundus observation, the examiner performs a selection operation of visible light / infrared light at the time of observation via the observation light source selection switch 22. At this time, the anterior eye observation lens 13 is retracted from the optical path O2. The observation light source 1 is selected for mydriatic imaging, and the infrared LED 7 is selected for non-mydriatic imaging. The illumination light from the optical path illuminates the fundus of the eye E through the split unit 10 and the perforated mirror 12 and the objective lens 2.

  In the case of visible light from the observation light source 1, the reflected image on the fundus is reflected by the movable mirror 15 inserted in the photographing optical path O <b> 2 and observed by the examiner using the finder eyepiece 18. On the other hand, in the case of using infrared light from the infrared LED 7, the image is taken by the imaging device 16 and observed using the monitor unit 49. The examiner observes the fundus image directly or operates the focus adjustment knob 28 while viewing the index image by the split unit 10 via the monitor unit 49, and drives the focus lens 14 to perform focusing.

  When the photographing button 48 is pressed and photographing is started, the split unit 10 and the movable mirror 15 are retracted from the optical path, and the fundus is irradiated through the illumination mirror 5 that emits light from the photographing light source 3 and reflects visible light. The image is picked up by the image pickup device 16 through the focus lens 14. The image sensor 16 photoelectrically converts the obtained fundus image, outputs it to the system control unit 21, converts it into digital data, and records it on a recording medium (not shown).

  FIG. 3 is an operation flowchart when the left / right eye switching is detected. First, when the power is turned on in step S1, on or off is detected by the left and right eye detection switch in step S2. If no output is obtained from the left and right eye detection switch, the process proceeds to step S3, and after substituting that the left eye is observed and photographed for the state storage variables a and b, the process proceeds to step S5.

  If a signal from the left and right eye detection switch is detected in step S2, the process proceeds to step S4. After substituting that the right eye is observed and photographed for the state storage variables a and b, the process proceeds to step S5.

  In step S5, the same determination as in step S2 is performed. If the left and right eye detection switch signal cannot be detected, the process proceeds to step S6. Step S6 is processing when the left and right eye detection switch signal detected in step S5 is OFF. After substituting that the left eye is observed and photographed for the state memory variable a, the process proceeds to step S8. If the left and right eye detection switch signal is detected in step S5, the process proceeds to step S7, and the state memory variable a is substituted for observation and photographing of the right eye, and then the process proceeds to step S8.

  In step S8, it is determined whether or not the state storage variables a and b are the same. If it is determined in step S8 that the state storage variables a and b are in the same state, the process returns to step S5. If it is determined in step S8 that the state storage variables a and b are different, the process proceeds to step S9.

  In step S <b> 9, the system control unit 21 moves the focus lens 14 in the direction of the origin position of the lens detection unit 26 that detects the origin position via the lens driving unit 32. In step S10, it is determined whether or not the lens detection unit 26 has detected the focus lens 14. If not, the process returns to step S9.

  In step S10, when the lens detection unit 26 detects the focus lens 14, the process proceeds to step S11, and the system control unit 21 sets the pulse counter of the lens detection unit 26 to 0 in order to grasp the position of the focus lens 14. To do. Thereafter, the process returns to step S2, and the left and right eye detection information is added to the captured image data.

  In addition, since the photographing operation and the observation operation are not performed when switching between the left and right eyes is detected, the examiner does not know that the origin of the focus lens 14 is calibrated. During the operation at the time of detecting the left / right eye switching by the command of the interface means, that is, during the photographing operation or the observation operation, the deviation of the absolute origin of the focus lens 14 and the drive pulse of the focus lens 14 is calibrated to calibrate the origin of the focus lens 14. Is possible.

  FIG. 4 is an operation flowchart for switching the observation site. First, in step S21, the process starts when the power is turned on. In step S22, it is determined whether or not the observation region switching button 46 is selected. If the observation region switching button 46 is not selected, step S22 is performed until it is selected. repeat.

  When the observation region switching button 46 is selected, the process proceeds to step S23, where the system control unit 21 drives the lens driving unit 32 and moves the focus lens 14 in the direction of the origin position. Subsequently, in step S24, it is determined whether or not the lens detection unit 26 has detected the focus lens 14, and if the lens detection unit 26 has not detected, the process returns to step S23. If the lens detection unit 26 detects in step S24, the process proceeds to step S25, and the system control unit 21 sets the count value of the pulse counter of the lens detection unit 26 to 0 in order to grasp the position of the focus lens 14. The process returns to step S22.

  In order to efficiently align the fundus with the fundus camera, it is better to insert the anterior eye observation lens 13 into the optical path and perform rough positioning by anterior eye observation before switching to fundus observation. The origin position of the focus lens 14 can be calibrated also when the image display is switched when the anterior eye observation lens 13 is inserted into the optical path.

  FIG. 5 is an operation flowchart when the photographing button 48 is selected. When the power is turned on in step S31, it is determined in step S32 whether or not the shooting button 48 has been selected. If the shooting button 48 is not selected, step S32 is repeated until it is selected. If selected, the process of step S33 and the process of step S34 are performed in parallel.

  In step S33, the system control unit 21 moves the focus lens 14 via the lens driving unit 32, and determines whether the lens detection unit 26 has detected the focus lens 14 in step S35. If the focus lens 14 is not detected in step S35, the process returns to step S33. If detected, the process proceeds to step S36, where the system control unit 21 sets a pulse counter for grasping the position of the focus lens 14 to 0, and then returns to step S32.

  In addition, the fundus image captured in step S34 is displayed on the monitor unit 49, and it is determined whether or not a predetermined time has elapsed since the fundus image was displayed in step S37. If the predetermined time has not elapsed since the captured image data was displayed, the process returns to step S34. If a predetermined time has elapsed since the fundus image was displayed, the process proceeds to step S38. In step S38, the display of the fundus image on the monitor unit 49 is terminated.

  In photographing with this fundus camera, it is indispensable to check the fundus image immediately after photographing. If neglected, there is a risk of going to the examination room or clinic again and taking a picture again. Therefore, no observation operation or imaging operation is performed while the examiner is checking the displayed image. During this time, the deviation between the absolute origin of the focus lens 14 and the drive pulse of the focus lens 14 is calibrated by setting the pulse counter to 0, whereby the origin of the focus lens 14 can be calibrated.

  FIG. 6 is a flowchart until the observation light source 1 is turned off and the origin of the focus lens 14 is determined. First, when the power is turned on in step S41, the time counter that counts the time when there is no input from the interface means is reset in step S42, and the process proceeds to step S43. In step S43, it is determined whether or not there is an input from the interface means. If there is an input from the interface means, the process proceeds to step S44, and after resetting the time counter, the process returns to step S43. In step S43, if there is no input from the interface means, the process proceeds to step S45 and the time counter is added.

  Next, in step S46, it is determined whether or not the predetermined count value of the time counter has reached a predetermined time. If not, the process returns to step S43. If it has reached, the process proceeds to step S47 to determine whether or not the observation light source 1 is turned off. If the observation light source 1 is turned off, the process returns to step S43. If the observation light source 1 is not turned off, the process proceeds to step S48, and the observation light source 1 is turned off.

  In step S49, the system control unit 21 moves the focus lens 14 through the lens driving unit 32 in the direction of the lens detection unit 26 that is the origin position direction. In step S50, it is determined whether or not the lens detection unit 26 has detected the focus lens 14. If the lens detection unit 26 has not detected, the process returns to step S49, and if detected, the process proceeds to step S51. In step S51, in order for the system control unit 21 to grasp the position of the focus lens 14, the pulse counter of the lens detection unit 26 is set to 0, and then the process returns to step S43.

  Moreover, since the observation light source 1 is a consumable item, it must be replaced after being used for a predetermined time. In order to extend this replacement time, when the fundus camera is not operated for a predetermined time, it is assumed that the fundus camera is not used and the observation light source 1 is turned off. During this time, by calibrating the absolute origin of the focus lens 14 and the shift of the driving pulse of the focus lens 14, the origin of the focus lens 14 can be calibrated without any trouble in the observation and photographing of the examiner.

  FIG. 7 is a flowchart for determining the origin of the focus lens 14 when the photographing mode is switched. When the power is turned on in step S61, it is determined whether or not the shooting mode switching button 47 is selected in step S62. If the shooting mode switching button 47 is not selected, step S62 is repeated until the shooting mode switching button 47 is selected. When the shooting mode switching button 47 is selected, the processes in steps S63 and S64 are performed in parallel.

  First, in step S63, the optical filters 9a to 9d of the optical filter unit 9 are switched corresponding to the selected photographing mode, and then the process proceeds to step S65. In step S65, the capacitor 33 supplied to the imaging light source 3 corresponding to the selected imaging mode is charged and discharged to adjust the charge, and the process proceeds to step S66 and ends.

  In step S64, the system control unit 21 drives the lens driving unit 32 to move the focus lens 14 in the direction of the lens detection unit 26 that is the origin position direction. Subsequently, in step S67, it is determined whether the lens detection unit 26 has detected the focus lens 14. If not, the process returns to step S64. When the focus lens 14 is detected, the process proceeds to step S68, and the system control unit 21 sets the pulse counter of the lens detection unit 26 to 0 in order to grasp the position of the focus lens 14, and then proceeds to step S69 and ends.

  Every time the eye E is photographed, the optical filters 9a to 9d are switched when the photographing mode is switched, and the capacitor 33 that supplies power to the photographing light source 3 is always charged. During the switching of the optical filters 9a to 9d, the charging of the capacitor 33, or the mirror raising operation of the movable mirror 15, the deviation between the absolute origin of the focus lens 14 and the drive pulse of the focus lens 14 is calibrated to thereby adjust the focus. The origin calibration of the lens 14 becomes possible.

  In the embodiment, the optical member disposed in the observation photographing optical path is the focus lens 14, but may be another zoom lens, for example.

DESCRIPTION OF SYMBOLS 1 Light source for observation 3 Light source for imaging | photography 9 Optical filter unit 10 Split unit 14 Focus lens 21 System control part 26 Lens detection part 32 Lens drive part

Claims (4)

  Interface means for commanding the operation, position control means for controlling the position of the optical member disposed in the observation and photographing optical path to function its optical characteristics, detection means for detecting the origin position of the optical member, and Calibration means for calibrating the origin position of the optical member based on the output, imaging means for photographing the fundus via the optical member, and the detection means and the calibration means between operations according to commands of the interface means A fundus camera comprising system control means for operating the fundus camera.   The operation of the detecting means and the calibrating means by the system control means is as follows: when the left / right eye switching is detected by the command of the interface means, when the observation part is switched, when the image display is switched, while the observation light source is turned off. 2. The fundus camera according to claim 1, wherein the fundus camera is operated during the switching of the mode, during charging of the capacitor, or during at least one operation during the mirror-up operation of the movable mirror.   2. The fundus camera according to claim 1, wherein the calibration of the origin position of the optical member by the calibration unit is performed by setting a count value of a pulse counter that counts driving pulses of the optical member to 0. 3.   The fundus camera according to claim 1, wherein the optical member is a focus lens.

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