JPS6219853B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ophthalmological photographing apparatus capable of performing ordinary color or monochrome photographing and fluorescent fundus photographing.

Fluorescence fundus photography, which is known as a type of fundus photography, measures the time when the contrast agent frioretsen sodium injected through the cubital vein reaches the intraocular circulation system, and then illuminates the fundus with blue excitation light. This is done by illuminating the blood vessels and photographing the green-yellow fluorescence emitted by the contrast agent in the blood vessels. At that time, a barrier filter (also called a superfilter, which has a greenish-yellow color and has the function of passing only fluorescent light from the fundus reflected light) with characteristics as shown in Figure 2 (b) is placed in the photographing optical path, and In the illumination optical path is an exciter filter (also called an excitation filter, which is blue in color and has the function of passing light in a wavelength range suitable for exciting fluorescent substances from white light) with characteristics as shown in Figure 2 A. ) is attached to perform wavelength separation.

In addition, especially during fluorescence photography, it is necessary to know how the contrast medium flows through the blood vessels over time, and in order to record the progress on a photograph, it is necessary to imprint data related to time onto the film. is given great importance. Note that during normal photographing, the data to be recorded is written on a counter or a card, and the data is imprinted.

With a general fundus camera, when performing color (black and white) photography when the light source for fundus photography and the light source for data photography are separate, the light intensity for fundus photography and the light intensity for data photography only need to be increased or decreased at the same rate depending on the ASA sensitivity of the film. . Therefore, the light amount can be set simultaneously according to the ASA sensitivity of the film.

However, when performing fluorescence photography, barrier filters and exciter filters are installed to separate the wavelengths as described above.
The amount of light decreases depending on the transmission characteristics of the filter, and since the emission of fluorescent light generated in the fundus of the eye is quite low, a greater amount of illumination light is required than in general photography. At the same time, a film with high ASA sensitivity is used or a sensitization phenomenon is performed. Therefore, in the case of fluorescence photography, it is necessary to set the fundus photography light amount and data photography separately.

An object of the present invention is to solve the problem of forgetting to adjust one side because the light intensity is set separately, or that the adjustment is complicated. Similarly, an embodiment in which the fundus recording light amount and the time-related data recording light amount as described above are set at the same time, and the data recording light amount can be adjusted in conjunction with the attachment of a filter, which is always operated during fluorescence photography. The purpose of this will become clear.

Embodiments of the present invention will be described below with reference to FIGS. 1, 3, and 4. First, FIG. 1 shows a fundus photographing system, an illumination system, and a data photographing system. In the figure, 1 is an observation light source such as a tungsten lamp, and 1a
is a condenser mirror, 2a and 2b are condenser lenses, 3
4 is a photographic light source such as a xenon discharge tube, 4 is a ring slit plate having an annular opening, and 5 is a mirror. Reference numeral 21 denotes an exciter filter, which is moved out of the optical path during color photography and inserted into the illumination optical path during fluorescence photography by a mechanism not shown. 6a and 6b are relay lenses, 7 is a mirror-like beam splitter with an aperture in the center, 8 is an objective lens, Ep is the eye to be examined, Ei is its iris, El
is the lens, and Ef is the fundus. Furthermore, 22 is a barrier filter, which can be attached to and removed from the optical path in conjunction with or independently of the filter 21 described above. Further, 9 is a focusing lens, 10 is a photographing lens group, 11 is a movable mirror, 12 is a shutter, and 13 is a film.
14 is a field lens, 15 is a mirror, 16 is an eyepiece, and Eo is the examiner's eye. To summarize the function of this fundus camera, the light sources 1 and 3 are almost conjugate with respect to the condenser lens 2a, and a light source image is once formed near the ring slit plate 4 by another condenser lens 2b, and then the light source image is formed near the ring slit plate 4. 6b forms an image of the annular aperture 4 in the vicinity of the beam splitter 7, and moves to the left due to its mirror action. Then, after focusing the image of the annular aperture 4 near the crystalline lens Ei again with the objective lens 8, the fundus Ef
to illuminate. The above is the illumination system optical path, and of course the observation light source 1 is turned on during observation, and the photographing light source 3 is turned on during photography.

Next, regarding the imaging system, the reflected light from the fundus Ef travels to the right, and the lens El and the objective lens 8
Once imaged by Guided upward by the movable mirror 11, the finder 14~
observed by 16.

When taking a photograph, the movable mirror 11 is rotated to the position indicated by the two-dot chain line, the shutter 12 is opened, and an image is formed on the film 13.

The data shooting system is a strobe light source for data illumination.
7, data 18, mirror 19, and imaging lens 20, the movable mirror 11 rotates, and the shutter 1
2 opens, the light source 17 emits light to illuminate the data 18, and the light beam reflected from the data 18 is reflected from the mirror 1.
9 and is imaged onto the film 13 by the imaging lens 20, thereby recording data.

Figures 3 and 4 show a device for inserting a light intensity reduction filter in conjunction with a barrier filter in the data photography optical path. Figure 3 shows the case of ordinary color photography, and Figure 4 shows the case of fluorescence photography. But before that, let's talk about the selection of light intensity. FIG. 5 shows a light amount selection button provided on the exterior of the fundus camera body, and the light amount can be selected by pressing any button. For example, when photographing with AS400 film, press the light amount select button 25WS shown in FIG. 5, and when using ASA25, select 300WS to perform fundus photographing and data imprinting in the optimal exposure state. When performing fluorescence photography, due to the combination of narrow spectral width filters shown in Figure 2, the amount of light that returns from the fundus is much smaller than in normal photography, so it is necessary to use high-sensitivity film. It also requires a large amount of shooting light. It is necessary to select 300WS with ASA400 film. At that time, the light intensity for data imprinting is designed to match the ASA25 film, so the light intensity must be lowered. Therefore, a method is adopted in which a filter (to reduce the amount of light) is installed as part of the data imprinting optical system. During color (black and white) photography, the light intensity reduction filter holding arm 24 is rotated by the spring 27 about the arm support 25 as shown in Fig. 3, and the light intensity reduction filter 26 escapes from the optical path of the data capturing optical system. There is. When performing fluorescence photography, the barrier filter 22 is attached as shown in Figure 4, but as the barrier filter holding base 23 moves, a force is applied in the opposite direction to the spring force, causing the arm support 25 to become the center of rotation. The light amount reduction filter holding arm 24 rotates as
The light amount reduction filter 26 allows proper exposure to be obtained even when data is imprinted.

In the case of fluorescence photography, not only a barrier filter is used in the photography system, but also an exciter filter 21 is used in the illumination system.
As shown in FIG. 6, in conjunction with the movement of the exciter filter holder 28, the light amount reducing filter 26 can be inserted into and removed from the data photographing optical system in the same manner as in conjunction with the barrier filter.

FIGS. 7 and 8 show a second embodiment. In conjunction with the insertion of a filter for fluorescence photography, a method is adopted in which the amount of light is changed by changing the F number of the lens for data photography in the data photography optical system instead of the light intensity reduction filter shown in the previous embodiment. .
At that time, in order to change only the brightness without interfering with the field of view of the data, an aperture is placed near the aperture of the data-taking lens. FIG. 7 shows the case of general photography, in which the light amount reduction diaphragm holding arm 30 is rotated by the spring 27 around the arm support 25, and the diaphragm 29 placed near the aperture of the data photography lens 20 escapes from the data photography optical system. ing. When performing fluorescence photography, the barrier filter 22 is attached as shown in FIG. The light amount reducing diaphragm holding arm 30 rotates around the center, and the diaphragm 29 enters the data photographing optical system. The aperture 29 allows proper exposure to be obtained even when imprinting data.

In the case of fluorescence photography, not only a barrier filter is used in the photography system, but also an exciter filter 21 is used in the illumination system.
As shown in FIG. 9, in conjunction with the movement of the exciter filter holder 28, the aperture can be moved in and out of the data photographing optical system in the same manner as in conjunction with the barrier filter.

The above explanation is for the case where the data illumination light source is separate from the fundus photographing light source, but the same effect can be obtained when the data illumination light source is shared by guiding the light from the fundus photographing light source with an optical fiber or the like. Conceivable.

Furthermore, the same effect can be obtained not only by an optical method but also by an electrical method. The method is to increase or decrease the amount of light by regulating the flashing time of the data illumination strobe 17 shown in Figure 1. This structure changes the CR time constant in conjunction with the attachment and detachment of the barrier filter and exciter filter, shortening the light emission time and reducing the amount of data illumination during fluorescence photography.

As described above, according to the present invention, the amount of light for capturing time-related data is changed in conjunction with fluorescence photography so that data related to time, which is important for diagnosis, can be reliably read during fluorescence photography. The advantage is that the amount of light for photographing time-related data can be set at once according to the ASA sensitivity of the film. In addition, not only in general photography methods (color photography) but also in the case of fluorescent photography, there is no need for settings to change the data photography light intensity, so there are no mistakes in the photography procedure, and the appropriate fundus photography light intensity and data photography light intensity can be adjusted. There is an effect that can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the fundus camera of the present invention. Figure 2 is a characteristic curve diagram of the filter. FIG. 3 and FIG. 4 are perspective views of respective embodiments. FIG. 5 is a plan view showing the light amount selection button. Figure 6, Figure 7, Figure 8,
FIG. 9 is a perspective view of each embodiment. In the figure, 1 is an observation light source, 3 is a photography light source, 8 is an objective lens, 13 is a film, 17 is a data illumination light source, 18 is data, 20 is an imaging lens, 21 is an exciter filter, 22 is a barrier filter, 26 29 is a light amount reduction filter, and 29 is an aperture.

Claims (1)

[Scope of Claims] 1 General photography and fluorescence photography of the fundus are performed in response to a predetermined sensitivity and an information recording carrier having a sensitivity higher than the predetermined sensitivity, and data photography is possible together with each photography, and fluorescence photography is possible. A fundus camera that photographs time-related data during photographing, characterized in that the fundus camera has an adjustment means that reduces the time-related data photographing light amount in conjunction with fluorescence photographing compared to the data photographing light amount during general photographing. 2. The fundus camera according to claim 1, wherein the adjustment means is a filter. 3. The fundus camera according to claim 1, wherein the adjusting means is an aperture of a data photographing system. 4. The fundus camera according to claim 1, wherein the adjustment means is a data light source light amount control means.