JPH0339A - Ophthalmology imaging device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an ophthalmological photographing apparatus for illuminating the fundus of the eye with illumination light emitted from a xenon lamp and photographing the fundus using a TV camera.

(Conventional technology) Generally, when taking fluorescent photographs of the fundus, a fluorescent agent is injected into the veins of the subject (intravenous injection), and once the fluorescent agent begins to circulate in the fundus, the fundus is excited with a predetermined wavelength. The fundus is photographed by illuminating it with light and emitting fluorescence of a specific wavelength from the fluorescent agent in the blood vessels of the fundus. When photographing, an exciter filter that transmits excitation light of a predetermined wavelength is inserted in the illumination optical path, and a barrier filter that transmits fluorescence of a particular wavelength and removes excitation light of the predetermined wavelength is inserted in the photographic optical path. do.

For fluorescence photography, T
A V-camera is used, and a xenon lamp is used as a light source for illuminating the fundus.

(Problem to be Solved by the Invention) By the way, as shown in Fig. 4, the amount of light emitted by a xenon lamp increases with the passage of time after it starts emitting light, and when it reaches its peak, the amount of light emitted increases. is decreasing. On the other hand, an image taken with a TV camera will cause halation if the amount of light exceeds a predetermined amount of light.

Therefore, in conventional ophthalmological imaging devices, the peak value of the amount of emitted light is manually set to prevent halation. However, it is difficult to determine at first what amount of light is required to cause halation in 1 fl of photography. As a result, halation occurs in the first captured image, and even if the set value of the light emission amount is known in advance, the user forgets to set it, resulting in the problem that the first recorded image becomes stale. was there.

(Object of the Invention) The present invention has been made in view of the above-mentioned problems, and its object is to provide an ophthalmological photographing device that does not cause halation in photographed images.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the present invention provides an ophthalmological photographing apparatus for illuminating the fundus of the eye with illumination light emitted from a xenon lamp and photographing the fundus of the eye using a TV camera as a fluorescent image. a light receiving sensor that receives reflected light from the fundus of the eye and outputs a received light signal according to the amount of received light; and a value of the received light signal is determined by comparing the value of the received light signal with a reference value corresponding to the white clip level of the TV camera. The present invention is characterized in that a light emission stopping means is provided for stopping light emission of the xenon lamp when the xenon lamp becomes equal to or higher than a reference value.

Further, in an ophthalmologic imaging device that illuminates the fundus of the eye with illumination light emitted from a xenon lamp and photographs the fundus with fluorescence using a TV camera, the amount of light emitted from the xenon lamp starts emitting light is equal to the white clip level of the TV camera. (The present invention is characterized in that a light emission stopping means is provided for stopping the light emission of the xenon lamp when the time reaches this point.

(Function) Since the present invention has the above configuration, the light receiving sensor receives the reflected light from the fundus and outputs a light receiving signal according to the amount of the received light, and the light emission stopping means combines the value of the light receiving signal and the TV camera. When the value of the received light signal exceeds the reference value by comparing it with a reference value corresponding to the white clip level, the xenon lamp stops emitting light.

Further, the light emission stopping means stops the light emission of the xenon lamp when the amount of light emission reaches the white clip level of the TV camera after the xenon lamp starts emitting light.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a schematic layout diagram showing the arrangement of the optical system of the II department imaging device according to the present invention.
This is an illumination optical system that illuminates the fundus Er of the eye.

The observation optical system 1 includes an objective lens 3 facing the eye E to be examined;
Focusing lens 4, relay lens 5, mirror 6, and TV
It consists of a camera 7. This observation optical system 1 includes a barrier filter 8 that can be switched between the inside and outside of the optical path, and a light receiving current ( A light receiving sensor 9 that outputs a light receiving signal) is provided. Barrier filter 8
is for transmitting light with a wavelength of 850 nm. 10
is a monitor.

The illumination optical system 30 includes an objective lens 3 and an apertured mirror 31.
, a relay lens 32, a mirror 33, a relay lens 34, a ring aperture plate 35 having a ring aperture 35a located at a conjugate position with the pupil Ea, a relay lens 36, and a xenon lamp that emits illumination light for fluorescence photography. It consists of 37. This illumination optical system 3o includes an exciter filter 38 that can be switched between the optical path and a position outside the optical path, and illumination light that illuminates the fundus! 39. Relay lens 40. Half mirror 41
etc. are provided. The exciter filter 38 is 75
It allows light with a wavelength of 0 nm to pass through.

When observing the fundus Er, the exciter filter 38
Then, switch the barrier filter 8 to the position indicated by the broken line and remove it from the optical path. Next, illumination light is emitted from the illumination light source 39. This illumination light includes a relay lens 40, a half mirror 41,
Ring aperture plate 35, relay lens 34, mirror 33, relay lens 32, perforated mirror 31, and objective lens 3
The light is incident on the eye to be examined El; Then, an aperture image of the ring aperture 35a is formed in the pupil Ea, and the fundus Er is illuminated by this aperture image.

The reflected light flux from the fundus E is reflected by the objective lens 3 and the perforated mirror 3.
1. A TV camera is reached via a focusing lens 4, a relay lens 5, a mirror 6, and a half mirror H, and the fundus Er is observed on a monitor 10.

When performing fluorescence photography of the fundus Er, the exciter filter 38 and the barrier filter 8 are switched to the positions indicated by solid lines and inserted into the optical path, and the xenon lamp 37 is turned on.

FIG. 2 is a block diagram showing the configuration of the control system of the above-mentioned ophthalmological imaging device, in which 51 is a synchronization circuit that records an image in the frame memory 52 and outputs a synchronization signal;
is a start signal generation circuit that outputs a start signal for causing the xenon lamp 37 to emit light based on the synchronization signal.

Reference numeral 54 denotes a setting circuit for setting the light emission duration time of the xenon lamp 37, and this setting circuit 54 outputs an activation signal based on the start signal, and also outputs the start signal for the set duration time. When this happens, an operation stop signal is output.

Further, this setting circuit 54 is adapted to output an operation stop signal upon receiving the comparison signal mentioned above.

Reference numeral 55 denotes a xenon lamp light emitting circuit for causing the xenon lamp 37 to emit light, which causes the xenon lamp 37 to emit light upon receiving the activation signal, and stops the light emission upon receiving the activation stop signal.

56 is an integrating circuit that integrates the light receiving current output from the light receiving element 9 and outputs an integrated voltage according to the integrated value; 57 is a reference voltage corresponding to a level slightly lower than the white clip level of the TV camera 7; The set reference voltage generation circuit 58 is a comparison circuit that compares the integrated voltage with the reference voltage and outputs a comparison signal when the integrated voltage exceeds the reference voltage.

The setting circuit 54, the xenon lamp light emitting circuit 55, the integrating circuit 56, the reference voltage generating circuit 57, and the comparing circuit 58 constitute a light emission stopping means.

Next, the operation of the above-mentioned ophthalmologic photographing apparatus will be explained.

When photographing with infrared fluorescence, first, a fluorescent agent is intravenously injected into the subject. Next, the exciter filter 38 and the barrier filter 8 are inserted into the optical path, and when fluorescence begins to appear in the fundus Er, a start switch (not shown) is turned on. Then,
The start signal generation circuit 53 outputs a start signal matching the synchronization signal of the synchronization circuit 51, and the calibration circuit 54 receives the start signal and outputs an actuation signal.

The xenon lamp light emitting circuit 55 receives the operation signal and causes the xenon lamp 37 to emit light. Then, the m fundus Er is illuminated with light having a wavelength of 750 nm by the exciter filter 38, and fluorescence is emitted from the fundus Er by the R mole of the light.

The fluorescence is transmitted through an objective lens 3, an apertured mirror 31, a focusing lens 4, a barrier filter 8, a relay lens 5, and a mirror 6.
, reaches the TV camera 7 via the half mirror H, and the fundus Er
is photographed using fluorescence, and the fundus image is stored in the frame memory 521.Meanwhile, the fluorescence reaches the light receiving sensor 9 via the half mirror H, and the light receiving sensor 9 outputs a received light tt flow corresponding to the amount of received light. do.

By the way, as the amount of light emitted from the xenon lamp 37 increases over time as shown in FIG.
The amount of fluorescence from the sensor 9 also increases, and the light receiving current output from the light receiving sensor 9 also increases. Then, since the integrating circuit 56 integrates the light-receiving current, the integrated voltage increases with the passage of time.

When this integrated voltage exceeds the reference voltage, that is, reaches the white clip level of the TV camera 7, a comparison signal is output from the comparison circuit 58, and the setting circuit 54 receives the comparison signal and outputs an operation stop signal. When the xenon lamp light emitting circuit 55 receives the operation stop signal, the xenon lamp 3
70 Stop the light emission. For example, the light emission is stopped at tl shown in FIG.

In this way, when the integrated voltage of the integrating circuit 56 reaches the white clip level, the xenon lamp 37 stops emitting light, thereby preventing halation from occurring in the fundus image.

FIG. 3 shows a second embodiment, in which a time period from when the xenon lamp 37 emits light until halation occurs is set in advance, and when that time elapses, the emitted light from the xenon lamp 37 is This prevents halation. 61 is a voltage conversion circuit that converts the time measured by the setting circuit 54 into a voltage, and 62 is a reference voltage generation circuit that generates a reference voltage corresponding to a preset setting time. The voltage conversion circuit 61, the reference voltage generation circuit 62, the comparison circuit 58, and the setting circuit 54 constitute a light emission stopping means.

(Effects of the Invention) According to the present invention, there is provided a light receiving sensor that receives reflected light from the fundus of the eye and outputs a light receiving signal according to the amount of the received light, and a value of the light receiving signal that corresponds to a white clip level of the TV camera. and a light emission stop means for stopping the light emission of the xenon lamp when the value of the light reception signal exceeds the reference value by comparing the light reception signal with a reference value, and also for stopping light emission from the xenon lamp. Since a light emission stopping means is provided for stopping the light emission of the xenon lamp when the amount of light emission reaches the white clip level of the TV camera, halation can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the arrangement of the optical system of the ophthalmological imaging device according to the present invention, Fig. 2 is a block diagram showing the configuration of the control system of the ophthalmological imaging device, and Fig. 3 is a second embodiment. FIG. 4 is an explanatory diagram showing the relationship between the amount of light emitted from the xenon lamp and the elapsed time. 7...TV camera 9...Light receiving sensor 37...Xenon lamp 55...Xenon lamp light emitting circuit 56...Integrator circuit 57...Reference voltage generation circuit 58...Comparison circuit 61... Voltage conversion circuit 62...Reference voltage generation circuit

Claims (2)

[Claims] (1) In an ophthalmological photographing device that illuminates the fundus with illumination light emitted from a xenon lamp and photographs the fundus with a TV camera, a light reception signal is received that receives reflected light from the fundus and is responsive to the amount of received light. a light-receiving sensor that outputs a light-receiving sensor that compares the value of the light-receiving signal with a reference value corresponding to a white clip level of the TV camera, and stops emitting light from the xenon lamp when the value of the light-receiving signal exceeds the reference value. 1. An ophthalmologic photographing device characterized by comprising: a light emission stopping means for stopping light emission. (2) In an ophthalmologic imaging device that illuminates the fundus with illumination light emitted from a xenon lamp and photographs the fundus with a TV camera, the amount of light emitted from the time the xenon lamp starts emitting light is adjusted to the white clip of the TV camera. An ophthalmological photographing apparatus characterized in that an ophthalmological photographing apparatus is provided with a light emission stopping means for stopping light emission of the xenon lamp when the time reaches the level.