JP4515851B2 - Ophthalmic imaging equipment - Google Patents

Description

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

As a fundus camera, one using a general-purpose digital camera as a photographing means is known (see Patent Document 1). In addition, the fundus camera has an observation optical system, and while observing the subject's eye picked up by the observation camera of the observation optical system with a monitor or observing the subject's eye with the finder of the observation optical system, alignment with the subject's eye Execute the shooting after combining them.
JP 2002-58646 A

  By the way, a general-purpose digital camera generally includes a liquid crystal monitor for displaying a captured image stored and stored in an image memory, and a mode selection switch for selecting a shooting mode and a playback mode for reproducing the captured image on the liquid crystal monitor. Is provided. In general-purpose digital cameras, the shooting mode and the playback mode are frequently switched in order to confirm the image captured immediately before or the image stored in the image memory.

  However, because of the configuration of the general-purpose digital camera, the mode selection switch signal cannot be taken out, so that the operation setting of the fundus camera cannot be switched using this. For this reason, the photographer sometimes starts photographing without noticing that the digital camera is set to the playback mode. That is, even if the state of the fundus camera is set to a state where the subject's eye can be observed and photographed, if the digital camera side is set to the playback mode, the photographing sequence is not executed and a photographing error occurs. In this case, the photographer switches the digital camera mode to the photographing mode and then performs alignment again. However, the photographing is not performed quickly, and a burden is placed on the photographer and the subject.

  The present invention provides a fundus camera that can reduce mistakes in shooting and can save the operation of a photographer even when photographing a fundus camera using a general-purpose digital camera in view of the problems of the above-described conventional apparatus. This is a technical issue.

(1) It has an observation means for observing the eye to be examined, a mode selection switch for selecting a photographing mode for enabling photographing and a reproduction mode for reproducing the photographed image, and does not output an image signal in the photographing mode. A fundus camera comprising: a general-purpose digital camera that outputs an image signal in a playback mode; and an output detection unit that detects the presence or absence of an image signal output from the digital camera, and a fundus based on the detection result And control means for switching camera operation settings.
(2) In the fundus camera according to (1), the observation unit displays an observation image sensor, an observation image of a moving image captured by the observation image sensor, and a captured image captured by the digital camera. A monitor, and the control means displays an observation image from the observation imaging device on the monitor when the output detection means does not detect the output of the image signal from the digital camera, and the output detection means When an output of an image signal from is detected, an image from a digital camera is displayed on the monitor.
(3) The fundus camera of (1) or (2) includes an observation illumination optical system, and the control unit controls turning off / on of illumination light of the observation illumination optical system based on a detection result of the output detection unit. It is characterized by that.

  According to the present invention, it is possible to reduce shooting mistakes due to erroneous mode setting of a digital camera. Further, it is possible to save the trouble of the photographer's operation. For this reason, appropriate photographing can be performed quickly.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a non-mydriatic retinal camera according to the present invention.

  The fundus camera of the embodiment includes a photographing unit unit 1 in which an optical system for observation and photographing is housed in a housing suitable for handheld operation, a single-lens reflex type general-purpose digital camera 50 detachably attached to the photographing unit unit 1, It is roughly divided into a control unit 2 that controls the photographing unit 1 and is provided with a photographing flash light source. The control unit 2 is provided with a color display monitor 3. Illumination light from the photographing flash light source of the control unit 2 is guided to the optical system in the photographing unit 1 via the fiber bundle 4. Reference numeral 6 denotes a photographing start switch for outputting a photographing start trigger signal. An observation light quantity adjustment knob 7 and a photographing light quantity adjustment knob 8 are provided on the outer surface of the control unit 2.

  FIG. 2 is an external view of the digital camera 50 as viewed from the back. Reference numeral 54 denotes a liquid crystal monitor for displaying captured images and setting screens. The digital camera 50 has a camera shooting mode for performing camera shooting and a playback mode in which a captured image can be confirmed again by displaying an already shot image on the liquid crystal monitor 54. In the playback mode, even if a shooting start signal is input, the shooting operation is not executed. Therefore, when the photographer performs fundus shooting, the camera shooting mode needs to be set. 55a is a selection switch for setting the camera photographing mode (drive mode), and 55b is a selection switch for setting the reproduction mode. In the playback mode, the photographed image can be switched to another image, or a plurality of images can be displayed at the same time, and the image can be switched or selected by operating the operation switch 56 including a cross key. Can do. Further, the digital camera 50 is provided with an image output terminal. By connecting a cable to the digital camera 50, the same image as the image displayed on the liquid crystal monitor 54 can be displayed on the display monitor 3 of the controller unit 2. .

  FIG. 3 is a diagram illustrating an optical system of the photographing unit 1 and the digital camera 50. The optical system includes an observation illumination optical system, a photographing illumination optical system, an observation optical system, a photographing optical system, and a fixation optical system.

  <Observation Illumination Optical System> 11 is an illumination light source for observation such as an infrared light emitting diode, 12 is a diffusion plate, 13 is a dichroic mirror, and the dichroic mirror 13 reflects infrared light and is visible light for photographing. It has the property of transmitting through. 14 is a condenser lens, and 15 is a slit plate, which has a pinhole opening and a ring slit opening around the optical axis at the center. Reference numeral 10 denotes a focus chart, which is composed of a member that transmits visible light and infrared light, and a double ring index mark is formed on the chart surface. The double ring index mark is made of a coating having a wavelength characteristic that transmits light in the visible region and shields light in the infrared region. The focus chart 10 moves in the optical axis direction (arrow direction) in conjunction with a focusing lens 23 of an observation / photographing optical system, which will be described later, and is placed at a position conjugate with the fundus. Reference numeral 16 denotes a light projection lens, and reference numeral 17 denotes a half mirror. The illumination / index projection optical axis and the optical axis of an observation / photographing optical system described later are coaxial. A black absorber 19 absorbs the illumination light beam that has passed through the half mirror 17 to prevent unnecessary noise light from entering the observation / photographing optical system. Reference numeral 18 denotes an eye to be examined.

  The infrared light beam emitted from the light source 11 illuminates the eye to be examined through the diffusion plate 12, the dichroic mirror 13, the condenser lens 14, the slit plate 15, the focus chart 10, and the half mirror 17.

  <Photographing Illumination Optical System> 31 is a flash light source for photographing, 32 is a condenser lens, and the illumination light beam for photographing is guided to the photographing unit unit 1 through the fiber bundle 4. The photographing illumination optical system in the photographing unit unit 1 shares the optical path from the dichroic mirror 13 to the half mirror 17 of the observation illumination optical system.

  <Observation Optical System> 21 is an objective lens, and 22 is a photographing aperture arranged at a position conjugate with the pupil of the eye 18 to be examined. Reference numeral 23 denotes a focusing lens, which can be moved in the optical axis direction by a lens moving mechanism (not shown) in order to perform adjustment according to the refractive power of the eye to be examined. Reference numeral 24 denotes a relay lens, and 25 denotes a dichroic mirror. The dichroic mirror 25 has a characteristic of reflecting a part of infrared light and visible light and transmitting most of the visible light. 27 is a relay lens for extending the optical path, 28 is a dichroic mirror that transmits visible light and reflects infrared light, and 29 is an infrared CCD camera for observation.

  <Photographing optical system> The photographing optical system shares the objective lens 21 to the relay lens 24 of the observation optical system. A digital camera 50 is attached in the transmission direction of the dichroic mirror 25 via an imaging lens 33. Reference numeral 41 denotes a flip-up mirror, and reference numeral 42 denotes an imaging element for photographing. Since the digital camera 50 is a single-lens reflex type, the digital camera 50 includes a pentagonal prism 44 and an eyepiece 45 arranged in the reflection direction of the flip-up mirror.

  The visible reflected light beam from the fundus illuminated by the visible light by the light emission of the flash light source 31 passes through the objective lens 21, the photographing aperture 22, the focusing lens 23, and the relay lens 24 in the same manner as the fundus reflected light beam by the infrared light. , Enters the dichroic mirror 25. Since the dichroic mirror 25 transmits the visible light beam, the visible fundus reflected light beam is incident on the image sensor 42 of the digital camera 50 by the imaging lens 33 and forms a fundus image. At the time of shooting, the flip-up mirror 41 is removed from the optical axis L1 at the time of shooting.

  <Fixation Optical System> 30 is a fixation lamp for fixing the eye to be examined, and emits visible light. The visible light beam emitted from the fixation lamp 30 is directed to the eye to be examined through the dichroic mirror 28, the relay lens 27, and the dichroic mirror 25 to the half mirror 17.

  FIG. 4 shows a control system block diagram of the present apparatus. A control unit 40 provided in the control unit 2 controls the photographing unit 1 and transmits a photographing start signal to the digital camera 50 by input of a photographing start switch (release switch) 6. The control unit 40 is connected to the observation light amount adjustment knob 7, the photographing light amount adjustment knob 8, the flash lamp 31, the light source 11, the fixation lamp 30, and the observation camera 29. The observation light amount adjustment knob 7 is for adjusting the light amount of the observation light source 11, and the photographing light amount adjustment knob 8 is for adjusting the light amount of the flash lamp 31.

  A camera control unit 57 built in the housing of the digital camera 50 is connected to the image sensor 42, the liquid crystal monitor 54, mode selection switches 55 a and 55 b, operation switches 56, and an image memory 58. The camera control unit 57 stores the captured image sent from the image sensor 42 in the image memory 58. The trigger signal of the shooting start switch 6 is input to the camera control unit 57 via the cable 5a connected to the connection terminal of the digital camera 50. Further, the image signal from the image memory 58 is output to the control unit 2 via the cable 5 b connected to the connection terminal of the digital camera 50.

  Reference numeral 43 denotes a synchronization signal separation unit that separates a vertical synchronization signal and a horizontal synchronization signal included in the image signal. When the image signal is input from the cable 5b, a pulse of the vertical synchronization signal or the horizontal synchronization signal is obtained. The control unit 40 detects the presence / absence of an image signal output from the digital camera 50 by monitoring the presence / absence of the synchronization signal input from the synchronization signal separation unit 43.

  An image selection unit 64 has a role of switching and selecting either an image signal from the digital camera 50 or an image signal from the observation camera 29 in accordance with a command signal from the control unit 40. A character synthesis circuit 65 superimposes a signal such as a character or a symbol on the image signal from the image selection unit 64. The image signal selected by the image selection unit 64 is displayed on the display monitor 3 via the character synthesis circuit 65.

  The operation of the fundus camera having the above configuration will be described below. First, the operation when photographing the fundus of the eye to be examined with this apparatus will be described. The shooting environment should be such that the pupil of the subject's eye opens widely in a natural mydriatic state in a dark place that is barely light enough to read newspaper characters.

  The examiner operates the mode selection switch 55a to place the digital camera 50 in the camera photographing mode. At this time, the control unit 40 can determine the mode of the digital camera 50 from the presence or absence of an image signal from the cable 5b. That is, in the single-lens reflex type general-purpose digital camera 50, since the image signal is not output in the camera photographing mode, the synchronization signal separation unit 43 cannot obtain the synchronization signal. Therefore, no synchronization signal is input to the control unit 40. Accordingly, the control unit 40 can detect that no image signal is output from the digital camera 50, and as a result, can determine that the digital camera 50 is in the camera photographing mode.

  When it is determined that the digital camera 50 is in the camera photographing mode, the control unit 40 switches the operation mode of the fundus camera to a mode capable of photographing, and the image selection unit 64 displays the image signal from the observation camera 29 as a display monitor. Type in 3. At the same time, when the operation mode of the fundus camera is the photographing mode, the control unit 40 turns on the observation light source 11 and blinks the fixation lamp 30. On the display monitor 3, a moving image from the observation camera 29 is displayed in monochrome (black and white). Further, the control unit 40 superimposes characters representing the set photographing light amount level and observation light amount level on the image signal from the observation camera 29 on the screen of the display monitor 3 by the character composition circuit 65. The examiner can know the setting state of the operation mode of the fundus camera by looking at the display state of the display monitor 3 and can operate the observation light amount adjustment knob 7 and the photographing light amount adjustment knob 8 to easily adjust the light amount. .

  The examiner observes the eye to be examined while looking at the display monitor 3 and moves the photographing unit 1 to perform alignment with the eye to be examined. Since the focus chart 10 is projected on the fundus, the index image by the focus chart 10 is projected on the monitor 3 as a black shadow. The examiner observes the fundus image and the index image, and moves the focusing lens 23 so that the index image is focused, thereby focusing the fundus. After completing the focusing, the photographing start switch 6 is pressed to cause the flash light source 31 to emit light. The signal of the photographing start switch 6 is sent to the digital camera 50, and the fundus image is photographed on the image sensor 42 by removing the flip-up mirror 41 from the photographing optical path. When a fundus image is obtained from the image sensor 42, the captured image is stored in the image memory 58 of the digital camera 50.

  Next, an operation for confirming a photographed image stored in the image memory 58 of the digital camera 50 will be described. The examiner operates the mode selection switch 55b to set the digital camera 50 to the reproduction mode. Since the image signal is output in the reproduction mode, the synchronization signal separation unit 43 can obtain the synchronization signal. Therefore, the synchronization signal is input to the control unit 40. Accordingly, the control unit 40 can detect that an image signal is output from the digital camera 50, and as a result, can determine that the digital camera 50 is in a playback mode.

  When it is determined that the digital camera 50 is in the playback mode, the control unit 40 switches the operation mode of the fundus camera to the image playback mode, and the image selection unit 54 inputs the image signal from the digital camera 50 to the display monitor 3. To do. On the display monitor 3, an image captured by the digital camera 50 is displayed in color. Since the screen size of the display monitor 3 is larger than the monitor 54 provided in the digital camera 50, the examiner can confirm the quality of the fundus image by the display on the monitor 3. Further, when the control unit 40 determines that the digital camera 50 is in the playback mode, the control unit 40 turns off the observation light source 11 and the fixation lamp 30 (for the fixation lamp 30, the fixation of the eye to be inspected is stabilized). To keep it on) Note that the control unit 40 does not display the characters indicating the photographing light amount level and the observation light amount setting level displayed in the camera photographing mode, but instead displays characters indicating the reproduction mode.

  When an image in the playback mode is displayed on the display monitor 3, the captured image can be confirmed on a screen larger than the confirmation screen of the liquid crystal monitor 54. The examiner can switch the photographed image to another image by operating the operation switch 56 of the digital camera 50 while looking at the display monitor 3. When the operation switch 56 is switched to display a plurality of thumbnail images, the same image as the image reproduced on the digital camera 50 side is displayed on the display monitor 3. Can be enlarged.

  Even when the setting of the digital camera 50 is the shooting mode selected state, the setting is made in the quick view when the digital camera 50 is set to the quick view (a function for temporarily playing back the shot image for the set time). Since the image signal is output for the set time, the control unit 40 switches the screen of the display monitor 3 from the monochrome image for observation to the color display of the captured image output from the digital camera 50 by the image selection unit 54. This also allows the examiner to confirm the quality of the captured image. When there is no image output from the digital camera 50, the control unit 40 detects this and switches from displaying the captured image on the display monitor 3 to displaying a monochrome image for observation.

  As described above, when the image signal is output from the digital camera 50 (in the quick view immediately after shooting or in the playback mode), the image from the digital camera 50 is displayed on the display monitor 3, and the digital camera 50 is displayed. When the image signal is not output from the camera, the image signal from the observation camera 29 is displayed on the display monitor 3 to easily confirm whether fundus photographing is possible. Then, the mode selection switches 55a and 55b of the digital camera 50 also switch the operation settings of the entire fundus camera in conjunction with each other. This saves the operator from having to switch and prevents forgetting to change the mode of the digital camera 50. As a result, rapid shooting is possible. In addition, since the current mode setting can be easily confirmed by a change in the display state of the monitor 3, a shooting mistake can be reduced.

  Further, since the control unit 2 can determine whether the digital camera 50 is in the camera photographing mode or the reproduction mode, the setting state of the device that turns on / off the observation light source 11 and the fixation lamp 30 can be switched. . As a result, useless power consumption can be reduced and the lifetime of the element can be extended. Further, the control unit 2 can determine whether or not to display characters on the display monitor 3 according to the mode of the digital camera 50, and can perform screen display according to the situation.

  In the above, the non-mydriatic fundus camera using the observation illumination light as infrared light has been described as an example, but a mydriatic fundus camera using the visible light as the observation illumination light may be used. A finder optical system is usually used for the observation optical system of the mydriatic retinal camera. Even in this case, the observation illumination light is controlled to be turned off when there is no image signal output from the digital camera 50. Thus, the examiner can easily check the mode setting state of the digital camera 50 by looking through the finder optical system, and can prevent mistakes that erroneously start shooting in the playback mode.

  When the quick view is set, the time after the shooting switch 6 is pressed and shooting is performed may be included in the determination element when switching the operation mode of the fundus camera. For example, even if the quick view is set when continuous shooting or the like is to be performed, the image signal output from the digital camera 50 is ignored and the fundus camera is ignored for an elapsed time longer than the settable time of the quick view. The operation mode of itself is kept in the photographing mode, and the input to the display monitor 3 is a moving image by the observation camera 29. Thus, the monitor 3 can continuously perform imaging while observing the eye to be inspected without displaying a quick view for each imaging.

  As means for notifying the examiner whether or not fundus photographing is possible, a screen display for notifying the mode of the digital camera 50 is performed on the display monitor 3, or a dedicated lamp is provided near the display monitor 3 of the control unit 2. Etc. may be provided to notify whether or not fundus photography is possible by turning on / off. Thereby, the examiner can confirm the mode setting state of the digital camera 50 from the control unit unit 2, and can start shooting smoothly.

It is a figure which shows schematic structure of the non-mydriatic retinal camera which concerns on this invention. It is an external view when a digital camera is seen from the back. It is a figure which shows the optical system of an imaging | photography unit and a digital camera. The control system block diagram of this apparatus is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shooting unit 2 Control unit 3 Display monitor 11 Light source 29 CCD camera for observation 40 Control part 42 Image pick-up element 43 Synchronization signal separation part 50 General-purpose digital camera 55a Selection switch 55b set to camera shooting mode (drive mode) 55b Set reproduction mode Selection switch 57 Camera control unit 64 Image selection unit 65 Character composition circuit

Claims (3)

Has a mode selection switch that selects observation means for observing the eye to be inspected, and a shooting mode for enabling shooting and a playback mode for playing back the shot image. In a fundus camera comprising a photographing means having a general-purpose digital camera that sometimes outputs an image signal,
A fundus camera comprising: output detection means for detecting presence / absence of an image signal output from the digital camera; and control means for switching operation settings of the fundus camera based on the detection result. 2. The fundus camera according to claim 1, wherein the observation means includes an observation image sensor, and a monitor for displaying an observation image of a moving image captured by the observation image sensor and a captured image captured by the digital camera. The control means displays an observation image from the observation image sensor on the monitor when the output detection means does not detect the output of the image signal from the digital camera, and the output detection means displays the image from the digital camera. A fundus camera characterized in that when a signal output is detected, an image from a digital camera is displayed on the monitor. The fundus camera according to claim 1 or 2, further comprising an observation illumination optical system, wherein the control means controls turning off / on of the illumination light of the observation illumination optical system based on a detection result of the output detection means. Fundus camera.