JPH11290278A - Ophthalmic imaging equipment - Google Patents

Abstract

(57) [Problem] To always shoot a clear image while observing the image quality of the image on a television monitor. A control means includes a focus adjustment switch.
When the input to is detected, the driving unit 23 is driven, and the imaging device 14 and the observation unit C are integrally driven in the photographing optical axis direction. The examiner operates the switch 25a or 24b in a direction in which the contrast is improved while observing the fundus image displayed on the television monitor 21, and ends the focusing when the contrast is in the best state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmologic photographing apparatus used in an ophthalmic clinic or the like.

[0002]

2. Description of the Related Art (1) Conventionally, in a fundus camera, a focus adjusting lens is disposed between a taking lens and a taking aperture in a taking optical system, and the position of the focus adjusting lens is adjusted in an optical axis direction. Focus adjustment.

(2) A normal ophthalmologic photographing apparatus is configured to move a finder and a film integrally to adjust a focus.

[0004]

(A) However, in the above-mentioned conventional example (1), a moving space for the focus adjusting lens is required, and the moving distance of the photographing lens corresponding to the spread of the light beam after passing through the photographing aperture is required. Since the aperture must be increased, the size of the optical system increases, and the area through which the light beam passes through the photographing lens changes with the movement of the focus adjustment lens, thereby deteriorating the image quality.

For this purpose, a focus adjusting lens having a focal length as short as possible may be used. However, the amount of focus shift per unit moving distance is increased, which makes accurate focus adjustment difficult. As described above, since the movement range of the focus adjustment lens cannot be widened due to restrictions due to the shooting aperture, the shooting lens, and the like, especially for an eye to be examined having large extraordinary refraction, another focus adjustment lens is inserted into and removed from the optical path. For example, it is necessary to expand the diopter adjustment range, which causes a problem that the structure is complicated.

A photoelectric conversion element such as a silver halide film or a CCD used as an image pickup means has different sensitivity depending on the incident angle of a light beam, and the efficiency is highest for a vertically incident light beam. Although the exit pupil of the system is at infinity, since the position of the exit pupil moves with the movement of the focus adjustment lens, the angle of incidence of the luminous flux toward the peripheral part of the image on the imaging means changes. There is a problem that an image becomes dark.

(B) In the above-mentioned conventional example (2), since the finder and the film must be moved integrally, the examiner looking through the finder also moves his face with the focus adjustment. However, there is a problem that the focus adjustment operation is difficult.

An object of the present invention is to solve the above-mentioned problems,
It is an object of the present invention to provide an ophthalmologic imaging apparatus that captures a clear image while always observing the image quality with a simple configuration.

Another object of the present invention is to provide an ophthalmologic photographing apparatus which secures a proper photographing position in accordance with a change in photographing magnification.

[0010]

An ophthalmologic photographing apparatus according to the present invention for achieving the above object has a first image pickup means capable of picking up a still image of an eye image to be inspected, and the first image pickup means substantially corresponding to the first image pickup means. A second imaging unit capable of imaging a moving image on the same plane,
And a movement control means for moving the first and second imaging means in the optical axis direction.

An ophthalmologic photographing apparatus according to the present invention comprises: a photographing optical system for selectively guiding an eye image to be inspected at different photographing magnifications to an image pickup means; Moving control means for moving to a predetermined position in the direction.

Further, the ophthalmologic photographing apparatus according to the present invention comprises a first photographing means capable of selectively photographing a still image of an eye image to be examined at different photographing magnifications, and a substantially same plane as the first photographing means. A second imaging unit capable of capturing a moving image with the display unit; a display unit for displaying a moving image by the second imaging unit;
First movement control means for moving the imaging means in the optical axis direction, and second movement control means for moving the first and second imaging means to a predetermined position in the optical axis direction according to the selected photographing magnification. And characterized in that:

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 shows a configuration diagram of a fundus camera according to a first embodiment, and includes a light source 1 such as a halogen lamp that emits steady light.
A condenser lens 3, a filter 4 that transmits infrared light and blocks visible light, a strobe light source 5, a lens 6, a stop 7 having a ring-shaped aperture,
A relay lens 8, a stop 9 having a ring-shaped opening, and a perforated mirror 10 having an opening at the center are sequentially arranged to form a fundus illumination means A.

On the optical path on the right side of the perforated mirror 10, a photographing aperture 11, a photographing lens 12, a mirror 13 that reflects infrared light and transmits visible light, and an image pickup device 14 are arranged to form a fundus photographing means B. Have been.

On the optical path in the reflection direction of the mirror 13, a lens 15, a mirror 16, a lens 17,
An imaging element 18 having an image plane at the same position as the optical element 4 is sequentially arranged, and a fundus observation means C is formed.

The outputs of the image pickup devices 14 and 18 are connected to an image control means 19, and the outputs of the image control means 19 are an image storage means 20, a television monitor 21, a control means 22, and an image pickup element 1.
4 and a fundus observation means C are connected to a driving means 23 which integrally moves in the direction of the arrow. The output of the control means 22 is connected to the strobe light source 5 and
Are connected to outputs of a focus adjustment switch 25 including a switch 25a for moving the imaging switch 24, the image sensor 14, and the fundus oculi observation means C closer to the subject's eye and a switch 25b for moving away from the subject.

A light beam emitted from the light source 1 is condensed by a condenser lens 3
, And visible light is blocked by the filter 4,
The pupil of the eye E passes through the strobe light source 5, the lens 6, the aperture of the aperture 7, the aperture of the lens 8, and the aperture 9, is reflected to the left by the mirror around the perforated mirror 10, passes through the objective lens 2, and passes through the objective lens 2. Illuminate the fundus through the eye. The fundus image illuminated in this way passes through the pupil, the objective lens 2, the aperture of the perforated mirror 10, the photographic stop 11, and the photographic lens 12 again.
The light is reflected upward by the mirror 13, passes through the lens 15, and
The light is reflected to the left by the mirror 16 and forms an image near the image sensor 18 by the lens 17.

This fundus image is converted into a video signal by the image pickup device 18, and transmitted to the television monitor 2 through the image control means 19.
1 is displayed. The examiner observes the fundus image displayed on the television monitor 21 to check the focus state and the like. At this time, if the examiner determines that the focus is too light and the contrast is not sufficient, the examiner operates the focus adjustment switch 25 to perform the focus adjustment. When the control unit 22 detects an input to the focus adjustment switch 25, it drives the driving unit 23 and
And the fundus observation means C are integrally driven in the direction of the photographing optical axis. The examiner observes the fundus image on the television monitor 21 and switches the switch 2 in the direction in which the contrast is improved.
By operating 5a or 25b, when the contrast reaches the best state, the focusing is completed.

When the examiner operates the photographing switch 25, the control means 22 controls the image pickup device 14 via the image control means 19.
Then, light accumulation for photographing a still image is started, the light source 1 is turned off, and the strobe light source 5 emits light. The visible light emitted from the strobe light source 5 passes through the lens 6 and then illuminates the fundus through the same optical path as the observation light. The fundus image illuminated in this way passes through the objective lens 2, the hole of the perforated mirror 10, the photographing stop 11, the lens 12, and the mirror 13, and forms an image on the imaging device 14 for photographing a still image. This still image is converted into a digital signal, and is stored in the image storage unit 2 via the image control unit 19.
0 and is reproduced on the television monitor 21.

Here, if the front focal position of the photographing lens 12 is arranged so as to substantially coincide with the photographing aperture 11, the exit pupil can always be kept at infinity. Can be made incident perpendicularly. Accordingly, the imaging element 14 can efficiently perform photoelectric conversion and obtain an image suitable for measurement without a change in magnification.

Even when relaying is performed using the lenses 15 and 17, since the pupil position does not change much,
Can be reduced, and the design of the optical system can be simplified by simplifying the configuration of the optical system.

Furthermore, since the restriction on the moving range of the image pickup devices 14 and 18 is reduced and the diopter adjustment range can be widened, the eye to be inspected having a large refractive error can be used without using a diopter correction lens for insertion / removal. , And the shooting operation can be simplified without complicating the structure.

FIG. 2 shows a second embodiment, in which a three-panel television camera 30 is used as an image pickup means. The three-panel television camera 30 includes color separation prisms 31a, 31b, 31
c and image sensors 32a, 32b, 32c, and the other configurations are the same as those in FIG. 1, and the same reference numerals denote the same members.

As in the first embodiment, the fundus image illuminated with visible light is color-separated by the color separation prisms 31a, 31b and 31c into three color images of red, green and blue. , 32b, 32c.

In the three-panel television camera 30, a light beam is separated into three colors by a color separation prism, and the wavelength of the color separation changes depending on the angle of a light beam incident on the prism. That is, when the exit pupil position of the optical system moves from infinity, the angle of the principal ray changes and the wavelength at which the prism separates wavelengths is different, so that color shading in which false colors appear in the vertical direction, which is the prism separation direction, occurs. .

In a system in which the focus adjusting lens is moved in the optical axis direction for focus adjustment as in the conventional example, the movement of the focus adjusting lens changes the exit pupil of the optical system, causing color shading. In this embodiment, the exit pupil can always be kept at infinity by making the focal position of the photographing lens 12 on the objective lens 2 side substantially coincide with the photographing stop 11, so that the imaging devices 14 and 18 are moved. Even if the focus adjustment is performed, the exit pupil position does not change, the occurrence of color shading can be prevented, and a photograph can always be taken with a natural color.

Color shading also occurs when the imaging magnification is changed by the optical system. Normally, in order to change the imaging magnification in the fundus camera, a part of the photographing lens 12 is moved in the optical axis direction, the imaging lens itself is replaced with a lens having a different focal length, or a new lens is added. And so on. However, in either method, the imaging magnification is changed by changing the focal length of the optical system between the photographing stop 11 and the image forming surface and the position of the principal point thereof without moving the image forming surface. The pupil position changes, which causes color shading to occur. It is also possible to arrange the principal point of the imaging optical system so as not to change the exit pupil position.However, in practice, the aperture of the lens cannot be secured, or the optical system becomes complicated There are problems such as insufficient.

FIG. 3 is a block diagram of a third embodiment, in which magnification changing means for changing the position on the optical axis of the three-panel television camera 30 to a predetermined position in accordance with a change in the photographing magnification is provided. This is an embodiment in which the occurrence of color shading due to the above is suppressed. Switches 35a, 35b, and 35c corresponding to angles of view of 60 degrees, 40 degrees, and 30 degrees are provided as switches 35 for selecting a shooting angle of view (shooting magnification), and the shooting lenses 12a, 12b, and 12c is selected and inserted into the optical path. Also, lens 1
In the optical path from 2 to the television camera 30, the infrared cut filter which is normally arranged is not arranged, and the infrared light reaches the television camera 30.
It is configured to observe the fundus of the eye E to be inspected by infrared light using mainly the red channel among the three imaging elements 32a to 32c. It should be noted that also in this configuration, observation can be performed optically on the same imaging plane.

FIG. 4 shows the photographing lens 12a when the photographing angle of view is selected.
FIG. 12 is an explanatory diagram of a positional relationship between the TV camera 30 and the three-panel television camera 30. FIG. 4A shows an arrangement in the case of photographing at an angle of view of 60 degrees. A fundus image is primarily formed between the objective lens 2 and the perforated mirror 10. Assuming that the focal length of the objective lens 2 is 21.5 mm, a fundus image with an angle of view of 60 degrees is formed at an image height of 12.4 mm. When three 1 / 3-inch image pickup devices are selected as the image pickup devices 32a to 32c, the size of the image pickup surface is about 3.6 mm in length and about 4.8 mm in width.

Assuming that the distance from the primary image forming plane to the photographing aperture 11 is 80 mm, it is necessary to form a primary image of the fundus image so that the upper and lower portions are the same size as the upper and lower portions of the image sensors 32a to 32c. The image magnification must be about 1 / 6.9 times. For this purpose, a photographing lens 12a having a focal length f = 11.6 mm is arranged so that its front focal position coincides with the photographing aperture 11, and about 13.3 mm in air conversion from the rear principal point position of the photographing lens 12a. The image sensors 32a to 32c may be arranged at the positions. Thus, the exit pupil is formed at infinity and color shading does not occur.

FIG. 4B shows a case where the angle of view is 40 degrees, the image height on the primary imaging plane is about 7.8 mm, and the imaging magnification is about 1 / 4.3. Therefore, the focal length is 18.4 m
m of the photographic lens 12b with the front focus position of the photographic aperture 1
1, and the image sensors 32a to 32c may be arranged at a position about 22.6 mm in air conversion from the rear principal point of the taking lens 12b. This gives 6
As in the case of 0 degrees, the exit pupil position is formed at infinity, and no color shading occurs.

FIG. 4C shows a case where the angle of view is 30 degrees. Similarly, the image height on the primary imaging plane is about 5.8, and the imaging magnification at this time is about 1 / 8.2. It is. Therefore, the photographing lens 12c having a focal length of about 25 mm is arranged so that the front focal position thereof coincides with the photographing aperture 11, and about 32.8 m in air conversion from the rear principal point position of the photographing lens 12c.
What is necessary is just to arrange | position the imaging elements 32a-32c in the position of m.
Thus, similarly to the case of 60 degrees and 40 degrees, the exit pupil position is not formed at infinity and color shading does not occur.

As described above, the magnification can be changed without causing color shading by moving the image pickup devices 32a to 32c to predetermined positions in accordance with the change in the imaging magnification.

In the above description, the method of changing the photographing magnification and replacing the photographing lenses 12a to 12c respectively has been described. However, the photographing lenses 12a to 12c are composed of a plurality of lenses, and their relative positions on the optical axis. Is changed to change the focal length of the photographing lenses 12a to 12c, the front focal position is arranged so as to coincide with the photographing aperture 11, and the image pickup devices 32a to 32c are moved to the image forming positions. You may. At this time, if the lens groups are continuously moved, and the imaging elements 32a to 32c are moved accordingly, zoom photographing in which the photographing magnification can be continuously changed can be performed.

In this embodiment, as shown in the first embodiment, the same effect can be obtained by finely adjusting the positions of the imaging elements 32a to 32c and performing focus adjustment. .

[0036]

As described above, the ophthalmologic photographing apparatus according to the present invention forms a moving image and a still image on substantially the same plane, and moves the two imaging means together while confirming them on the display means. By performing the alignment, the exit pupil position of the optical system does not change due to the focus adjustment, so that it is possible to prevent the image from being darkened and the image quality from deteriorating, to enable accurate focus adjustment, and to obtain an image with good contrast. Can be taken.

Further, in the ophthalmologic photographing apparatus according to the present invention, the imaging means is moved to a predetermined position in the optical axis direction in accordance with the photographing magnification. Efficiency can be improved.

In the ophthalmologic photographing apparatus according to the present invention, a moving image formed substantially on the same plane as the photographing plane for photographing a still image moving in the optical axis direction is confirmed on the display means, and the photographing magnification is changed. By moving the imaging means to a predetermined position, the magnification can be changed while the exit pupil position is always kept constant, so that the peripheral portion of the image becomes dark and color shading by the color separation prism is performed. Can be prevented, the efficiency of diagnosis can be improved, the focus driving and the variable power driving can be partially shared, and the structure can be simplified.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a configuration diagram of a second embodiment.

FIG. 3 is a configuration diagram of a third embodiment.

FIG. 4 is an explanatory diagram of an image forming position of a variable power lens.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light source 4 Filter 5 Strobe light source 10 Perforated mirror 11 Imaging aperture 12, 12a-12c Imaging lens 13 Wavelength selection mirror 14, 18, 32a-32c Imaging element 19 Image control means 20 Image storage means 21 Television monitor 22 Control means 23 Drive Means 24 Shooting switch 25 Focus adjustment switch 30 Three-panel television camera 31a to 31c Color separation prism 35 Shooting angle of view switch

Claims (5)

[Claims] A first imaging unit capable of capturing a still image of the eye image to be inspected; a second imaging unit capable of capturing a moving image on substantially the same plane as the first imaging unit; An ophthalmologic imaging apparatus comprising: a display unit for displaying a moving image by the imaging unit; and a movement control unit for moving the first and second imaging units in an optical axis direction. 2. The ophthalmologic imaging apparatus according to claim 1, wherein the second imaging unit has an imaging optical system for guiding a light beam to a plurality of imaging units via a color division optical system. 3. A photographing optical system for selectively guiding an eye image to be photographed to an image pickup means at different photographing magnifications, and movement control for moving the image pickup means to a predetermined position in the optical axis direction according to the photographing magnification of the photographing optical system. An ophthalmologic photographing apparatus comprising: 4. The ophthalmologic photographing apparatus according to claim 3, wherein the photographing optical system guides a light beam to a plurality of imaging units via a color division optical system. 5. A first imaging means capable of selectively capturing a still image of an eye image to be inspected at a different imaging magnification, and a second imaging means capable of capturing a moving image substantially on the same plane as the first imaging means. Imaging means; display means for displaying a moving image by the second imaging means; first movement control means for moving the first and second imaging means in the optical axis direction; And a second movement control means for moving the first and second imaging means to a predetermined position in the optical axis direction.