JP2003210410A - Fundus camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate color observation and color photographing by a fundus camera incorporating color image pickup elements. <P>SOLUTION: This fundus camera is provided with color image pickup means, a visible cut filter, display means displaying color or black/white image, means changing over between the color and black/white images according to the insertion/detachment of the visible cut filter, and means changing a gain of the imaging devices. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fundus camera used in an ophthalmic clinic or the like. 2. Description of the Related Art There is known a method of illuminating a fundus with infrared light, observing an infrared fundus image by displaying a monochrome image, and performing color photographing. In this method, the subject is not dazzled during the observation alignment, so that the subject can easily cooperate. In addition, black-and-white display using only the luminance signal of the video makes it easy to view the image and perform efficient shooting. However, only observation using infrared illumination light has a disadvantage that it is difficult to focus due to a difference between infrared light and visible light because the wavelength of illumination light differs between observation and photographing. Therefore, there is known a method in which an observation optical system is separately provided in the photographing optical system, the examiner is configured to be able to confirm with the naked eye using a finder, and a fundus image is observed. In recent years, a method of performing color observation or photographing of a fundus image or an anterior ocular segment image of an eye to be inspected using stationary light such as halogen with the increase in sensitivity of an electronic imaging device has been known. [0003] However, in the above-described configuration, when a finder is used, the optical path must be switched between infrared light observation and color visible observation. Also need to look at the viewfinder and monitor alternately. Further, when the image display device is used in both color and black and white, the television signal must be switched each time. In addition, since the reflectance of the fundus is generally higher in infrared light than in visible light, the sensitivity of the electronic imaging device must be higher than that of infrared light in order to perform observation and photographing with visible light. This not only complicates the structure, but also causes the examiner to easily fatigue. An object of the present invention is to solve the above problems. [0005] In order to achieve the above object, the invention according to the present application provides a light source that emits infrared light and visible light, an insertion / removal that blocks visible light and transmits infrared light. Filter means freely disposed, fundus imaging means for capturing a color of the eye image illuminated by the light source, display means for displaying the captured image in color or monochrome, according to the insertion and removal of the filter It is another object of the present invention to provide a fundus camera having switching control means for switching an image displayed on the display means and gain switching means for switching a gain of the imaging means. (Embodiment 1) FIG. 1 is a configuration diagram of a fundus camera. An objective lens 1 is arranged in front of the subject's eye E, and a perforated mirror 2, a photographing lens 3 movable for focusing, a movable mirror 4, an infrared wavelength region and a visible wavelength region are provided on an optical path behind the objective lens 1. An imaging means 6 such as a television camera having sensitivity is arranged. A fixation lamp 5 conjugated to the fundus Er is arranged in the direction of reflection (upward in the figure) of the movable mirror 4, and the eye to be examined E
The fixation target is presented to the
Is connected to the output of the control circuit unit 14. Eye E
The fixation target can be presented at an arbitrary position in response to an instruction from the control circuit unit 14. Thereby, the position of the eye E is fixed. In the direction of incidence of the illumination light on the perforated mirror 2, a condenser lens 8, a visible cut filter 9, which can be inserted and removed, and a flash of visible light from an observation light source 7 which emits visible light such as a halogen lamp. Stroboscopic light source 10, aperture 11 having a ring-shaped aperture,
The lenses 12 are arranged. [0008] The output of the imaging means 6 is connected to a control circuit section 14, A / D converted, and stored in a recording medium 17. The control circuit section 14 is connected to the position detecting means 13 of the visible cut filter 9 and the image switching control section 15, and further to the image switching control section 16, a television monitor 16 is connected. Have been. As described above, the objective lens 1 and the photographing lens 3 constitute a fundus observation photographing optical system.
In addition, a fundus imaging optical system configured to image the fundus Er of the eye E to be examined is configured. Further, an illumination optical system is constituted by an optical path from the observation light source 8 to the perforated mirror 2. Next, the operation will be described. In the case of infrared observation, an observation light source 8 such as halogen is used.
Is turned on, the visible cut filter 9 is inserted into the optical path, and the photographer first aligns the subject's eye with the objective lens 1, presents the fixation lamp 5 at a predetermined position, and moves the photographing lens 3. It is moved in the direction of the optical axis to check the imaging region. At this time, the position detecting means 13 (for example, a microswitch or the like) of the visible cut filter 9 is notified to the effect that the visible cut filter 9 is in the optical path to the control circuit unit 14 including the sensitivity switching means of the image sensor, and The switching control unit 15 outputs the output of the imaging unit 6 as a Y signal (luminance signal), and projects the eye image as a monochrome image on the television monitor 16. Here, it is efficient to use a color television camera that can output a Y / C (luminance / color) signal, an RGB (red-green-blue) signal, and a synchronization signal. Also, the sensitivity is set relatively low. After confirming the image projected on the television monitor 16, the photographer makes the strobe light source 10 emit light by a photographing switch (not shown), receives the fundus image of the eye to be examined, and converts the image into the recording medium 17 after A / D conversion. save. The stored color image is temporarily displayed on the television monitor 16 for confirmation. In the case of color observation, as in the case of infrared observation, the observation light source 8 such as halogen is turned on, and the visible cut filter 9 is retracted outside the optical path. The photographer performs alignment between the subject's eye and the objective lens 1, presents the fixation lamp 5 at a predetermined position, and moves the photographing lens 3 in the optical axis direction to confirm a photographed part. At this time, the position detecting means 13 (for example, a microswitch or the like) of the visible cut filter 9 is notified to the control circuit section 14 that the visible cut filter 9 is out of the optical path. Is output as an RBG signal (red-green-blue signal)
An eye image to be inspected is displayed on the television monitor 16 as a color image. At this time, the sensitivity is set higher than in the case of infrared light. The subsequent operation saves the color image in the same manner as in the case of the infrared observation described above. In the case of color observation, a moving image or a still image may be recorded using the observation light source 8 which is stationary light without emitting the strobe light source 10. FIG. 2 shows a flowchart of the photographing procedure described above. After detecting the position of the visible cut filter 9 in step S2 (step 2), an image output is selected and determined in step S3 (step 3). In the case of color observation, the image sensor is set to high sensitivity (step S3). ') And display it on the television monitor 16 (S4). (Other Embodiments) In the above embodiment, the insertion / removal of the visible cut filter 9 is detected,
Although the observation image was switched, an observation mode switching switch 18 was provided as shown in FIG. 1, and when the switch was actuated, the visible cut filter 9 was inserted into and removed from the optical path by a driving means such as a solenoid. The color or monochrome image and the sensitivity may be switched according to each state. Further, the output method of the television camera only needs to be equipped with any one of the Y / C signal, the RGB signal and the composite signal, and it is not necessary to have all the output methods. According to the present invention, according to the insertion / removal of the visible cut filter,
By providing a means for switching a video signal to be displayed and a means for switching the sensitivity of the image sensor, observation with infrared illumination light and observation with visible illumination can be easily switched.
The imaging efficiency can be improved without complicating the structure and minimizing the pain of the subject.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an arrangement of a fundus camera according to an embodiment of the present invention. FIG. 2 is a photographing flowchart of the fundus camera according to the embodiment of the present invention. [Description of Signs] 1 Objective lens 2 Perforated mirror 3 Photographing lens 6 Image sensor 9 Visible cut filter 13 Filter detection means 14 Control circuit unit 15 Image switching control unit 17 Recording medium 18 Observation mode selection switch

Claims (1)

Claims 1. A light source that emits infrared light and visible light, a filter means that blocks visible light and allows infrared light to pass through, and an examinee's eye illuminated by the light source A fundus imaging unit for capturing an image in color, a display unit for displaying the captured image in color or monochrome, and a switching control for switching a color or monochrome image to be displayed on the display unit in accordance with insertion / removal of the filter. A fundus camera having gain switching means for switching the gain between the means and the imaging means.