JPH05168596A - Ophthalmic photographing apparatus - Google Patents

Abstract

PURPOSE:To provide the subject apparatus capable of changing magnification without using a variable power optical system. CONSTITUTION:In an ophthalmic photographing apparatus equipped with a photographing optical system 1 taking the image of an eye to be examined, the photograping optical system is equipped with a first photographing element 10, a second photographing element 11 having a light detecting area smaller than that of the first photographing element 10 and having pixel density higher than that of the first photographing element 10, a mirror 8 allowing either one of the first and second photographing elements 10, 11 to perform photographing and a solenoid.

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 for photographing an eye to be examined by an image pickup device.

[0002]

2. Description of the Related Art Conventionally, for example, a fundus camera has been known as one of ophthalmologic photographing apparatuses. Such a fundus camera is
An illumination optical system for illuminating the fundus, a fixation target projection system for directing the eye to be examined in a predetermined direction, and a photographing optical system for photographing the fundus are included, and the photographing optical system magnifies the fundus for photographing. Therefore, it has a variable power optical system.

[0003]

However, in such an ophthalmologic photographing apparatus, since the magnification conversion of the fundus image is performed by the variable magnification optical system, the optical path length is inevitably increased when the magnification is increased. However, there is a problem that the working distance between the examiner and the examinee becomes long.

When photographing a desired portion of the fundus of the eye, the visual axis of the eye to be examined is guided in a predetermined direction so that the desired portion is on the optical axis of the optical system. The guidance is performed by moving the fixation target, but even a slight movement of the visual axis results in the same state as a large movement at high magnification, so moving the fixation target moves the desired portion onto the optical axis. There is a problem in that the guidance is a very troublesome work and both the examiner and the examinee feel annoyance.

Further, there is a problem that the subject is in pain when the subject is guided to a position where the visual axis is tilted considerably.

The present invention has been made in view of the above problems, and an object thereof is to provide an ophthalmologic photographing apparatus capable of changing the magnification without using a variable power optical system.

Further, an ophthalmologic photographing apparatus capable of photographing a desired portion with a simple guide of a fixation target even when photographing at a high magnification and in which the examinee's visual axis is only slightly tilted is provided. Especially.

[0008]

In order to achieve the above-mentioned object, the present invention is an ophthalmologic photographing apparatus provided with a photographing optical system for photographing an eye to be inspected, wherein the photographing optical system comprises a first image pickup device and , A second image pickup device having a light receiving area smaller than the light receiving area of the first image pickup device and having a pixel density higher than the pixel density of the first image pickup device, and shooting with either the first or second image pickup device And a switching means for performing.

[0009]

The present invention includes the second image pickup device having a light receiving area smaller than that of the first image pickup device and having a pixel density higher than that of the first image pickup device. When the image of the eye to be inspected is taken with the element, the taken eye to be inspected is enlarged and displayed on the display as compared with the case where the image is taken with the first imaging element.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of an ophthalmologic photographing apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic layout diagram showing the layout of an optical system of a non-mydriasis fundus camera which is one of the ophthalmologic photographing apparatus according to the present invention. In FIG. 1, 1 is a fundus Er of an eye E to be examined.
Is an illuminating optical system for illuminating the fundus Er of the eye E, and 50 is a fixation target projection optical system for projecting a fixation target onto the fundus Er.

The photographing optical system 1 is arranged at a conjugate position with the objective lens 3 facing the eye E to be examined, the focusing lens 4, the reflecting mirror 5, the photographing lens 6, the mirrors 7 and 8, and the fundus Er. CCDs 9 and 10 (first image sensor), 11 (second image sensor), etc., and light receiving surfaces 9a of the CCDs 9, 10 and 11,
10a and 11a have circular holes 12a to 14a of a predetermined size.
The open masks 12 to 14 are attached.

The CCD 9 is for observation and comprises an element sensitive to infrared light. The fundus image formed on the CCD 9 is displayed on the monitor 15 shown in FIG.

The CCDs 10 and 11 are composed of elements sensitive to visible light. The CCD 10 is used when photographing with low magnification, and the CCD 11 is used when photographing with high magnification. When the mirror 7 jumps up to the broken line position, the CCD 10 takes an image, and when the mirrors 7 and 8 jump up to the broken line position, the CCD 11 takes an image.

The light receiving surface 11a of the CCD 11 is the CCD 10
Is smaller than the area of the light receiving surface 10a, the number of pixels is the same, and the pixel density of the CCD 11 is higher than that of the CCD 10.

For example, when the vertical and horizontal lengths of the light receiving surface 11a of the CCD 11 are 1/10 of the vertical and horizontal lengths of the light receiving surface 10a of the CCD 10, respectively, the CCD1
When the image is taken at 1 and displayed on the monitor 15, it is displayed at a magnification of 10 times as compared with the case where the image is taken at the CCD 10. Moreover, since the number of pixels is the same, a resolution similar to that obtained when shooting with an optical system at a magnification of 10 is obtained. Further, the diameter of the hole 14a of the mask 14 is 1 times the diameter of the hole 13a of the mask 13.
The size of the image displayed on the monitor 15 is set to be equal to / 10.

As shown in FIG. 2, the CCD 11 is provided on the X stage 20, and the X stage 20 is movable along a rail 21 extending in the X direction.
The rail 21 is provided on the Y stage 22, and the Y stage 22 is movable along a rail 23 extending in the Y direction. The rail 23 is provided in a lens barrel (not shown), and the X, Y stages 20 and 22 are provided with motors 24 and 25.
(See FIG. 3) is moved in the X and Y directions.

By the movement of the X, Y stages 20 and 22, the CCD 11 can be moved to any position of the fundus image Er 'formed on the position of the X stage 20. That is, the CCD 11 can be moved to any position on the plane orthogonal to the optical axis 1a.

The illumination optical system 30 includes an objective lens 3, a perforated mirror 31, a relay lens 32, a mirror 33,
A relay lens 34, a ring aperture plate 35 having a ring aperture 35a at a position conjugate with the pupil Ea, a removable visible cut filter 38 for cutting visible light and transmitting infrared light, a condenser lens 36, and illumination. The light source 37 and the like.

The fixation target projection optical system 50 includes a half mirror 5.
1, a reflection mirror 52, a relay lens 53, and a fundus E
It is composed of r and a fixation target 54 or the like made of a light emitting diode arranged at a conjugate position. The fixation target 54 can be moved to an arbitrary position in a plane orthogonal to the optical axis and 50a. This movement is performed manually, but it may be automatically performed with the configuration shown in FIG. The half mirror 51 is adapted to jump to the position of the broken line at the time of shooting.

FIG. 3 is a block diagram showing the configuration of a control system for moving the X, Y stages 20, 22 and the like.

In FIG. 3, reference numeral 60 is an operation switch for setting the magnification of photographing and movement of the CCD 11, 61 is a storage device for storing the images photographed by the CCDs 10 and 11, and 62 is photographing. Solenoid that flips up the half mirror 51 to the broken line position when
Reference numerals 63 and 64 are solenoids for flipping the mirrors 7 and 8 to the broken line positions. The mirror 8 and the solenoid 64 form a switching means. 67 is a solenoid for inserting and removing the visible cut filter 38.

Reference numeral 65 is a motor 24, 25 and each solenoid 6
A control device for controlling 2 to 64, 67, etc., which is composed of a microcomputer or the like. This control device 6
5 is a storage device for storing images taken by the CCDs 10 and 11.
1 is stored in the storage device 61 or the image stored in the storage device 61 is displayed on the monitor 15. Reference numeral 66 is a joystick switch for photographing.

Next, the operation of the ophthalmic photographing apparatus of the above embodiment will be described.

First, a main switch (not shown) is turned on to cause the illumination light source 37 to emit light. The illumination light emitted from the illumination light source 37 is directed to the eye E through the condenser lens 34, the visible cut filter 38, the ring aperture plate 35, the relay lens 34, the mirror 33, the relay lens 32, the perforated mirror 31, and the objective lens 3. Infrared light enters. Then, an opening image is formed on the pupil Ea by the ring opening 35a of the ring opening plate 35, and the fundus Er is illuminated by this opening image.

The reflected luminous flux of the illumination light reflected by the fundus Er reaches the CCD 9 through the center of the pupil Ea, the objective lens 3, the perforated mirror 31, the focusing lens 4, the mirror 5, the taking lens 6 and the mirror 7. A fundus image Er 'is formed on the CCD 9 (see FIG. 2). Then, the fundus image Er ′ is displayed on the monitor 15.

At this time, the fixation target 54 is turned on, and the fixation target 54 is projected on the fundus Er via the relay lens 53, the reflection mirror 52, the half mirror 51, the perforated mirror 31, and the objective lens 3. Then, the subject's eye E is fixed by making the subject visually recognize the fixation target 54.

When photographing the fundus Er at a low magnification, the low magnification is set by operating the operation switch 60. Then, when the joystick switch 66 is pressed, the control device 65 actuates the solenoids 62, 63 and 67 to remove the visible cut filter 38 from the optical path and flip up the half mirror 51 and the mirror 7 to the broken line position. As a result, the fundus image is formed on the CCD 10, and the CCD 1
Shooting is executed by 0. Then, the fundus image captured by the CCD 10 is stored in the storage device. In this case, if the same CCD 10 as the CCD 9 is used, the monitor 1
The fundus image that is the same as the fundus image Er 'observed in 5 is captured.

After the photographing is performed, the solenoid 6
The operations of 2, 63 and 67 are stopped and the half mirror 51 and the mirror 7 are returned to the positions indicated by the solid lines.

When photographing the fundus Er at a high magnification, the high magnification is set by operating the operation switch 60. And
When the joystick switch 66 is pressed, the control device 65
Activates the solenoids 62 to 64 and 67 to remove the visible cut filter 38 from the optical path and flip up the half mirror 51 and the mirrors 7 and 8 to the broken line positions.
As a result, the fundus image is formed on the CCD 11,
Shooting is executed by 11. Then, the fundus image captured by the CCD 11 is stored in the storage device.

In this case, the fundus image Er 'as shown in FIG.
Image is formed, so that if the center of the CCD 11 is on the optical axis 1a, the image Eo 'of the central portion Eo of the fundus Er (see FIG. 1) is C
The image is formed on the CD 11, and the portion of the image Eo 'is photographed and stored in the storage device 61.
When the image Eo 'is displayed on the monitor 15, the image Eo' is enlarged and displayed at a high magnification as described above, and is in the same state as when the image is taken at a high magnification. Moreover, since the CCD 10 and the CCD 11 have the same number of pixels, the same resolution as that obtained when the magnification is changed and photographed by the optical system is obtained.

Further, as shown in FIG. 4, when the Ei portion of the fundus Er is photographed and displayed at a high magnification, the X, Y stage 2 is used.
Move 0 and 22 to move the image Ei 'position of the Ei portion (Fig. 2
The CCD 11 is moved to (see).

In this case, encoders 71 and 72 for detecting the amount of movement of the X and Y stages 20 and 22 are provided on the X and Y stages 20 and 22, and the control unit 65 causes the CCD 11 to output signals from the encoders 71 and 72. Of the fundus image Er as shown in FIG.
If it is displayed on the monitor 15 together with ', the CCD 11 can be moved to a desired position for high-magnification image display by operating the operation switch 66 while looking at the monitor 15. Then, the control device 65 and the encoders 71 and 72
A display means for displaying the mark M (position of the CCD 11) is constituted by the above.

In this way, by switching from the CCD 10 to the CCD 11, the image can be displayed at a high magnification, so that the working distance between the subject and the examiner does not become long. Further, when performing the photographing display at a high magnification, it is sufficient to move the CCD 11 to a desired position. Therefore, as in the prior art, the visual axis is guided by the fixation target and, for example, the fundus Er as shown in FIG.
Since it is not necessary to position the portion Ei on the optical axis 1a, both the examiner and the examinee can be freed from the trouble of the guiding operation.

Further, for example, as shown in FIG.
Even when photographing a portion Ej far away from the center of r, it is not necessary to position the portion Ej on the optical axis 1a.
That is, the fixation target 54 is moved so that the portion Ej falls within the photographing field of the photographing optical system 1, and the visual axis of the eye E to be examined is tilted.
Further, since the CCD 11 has only to be moved to the image forming position of the portion Ej, the inclination of the visual axis may be small, and the subject does not feel any pain. Further, the operation of the fixation target 54 may be rough.

In the above embodiment, the fundus image received by the CCD 9 is displayed on the monitor 15, but the fundus image received by the CCD 11 may be displayed on the monitor 15. For example, first, the fundus image received by the CCD 9 is displayed on the monitor 15, the mark M is moved to a desired position while observing the image on the monitor 15, and then the operation key 6 is pressed.
By operating 0, the mirrors 7 and 8 are flipped up to the positions of broken lines, and the fundus image received by the CCD 11 is monitored by the monitor 1.
5, the enlarged fundus image of the desired portion is displayed on the monitor 15. Then, the joystick switch 66 may be pressed while looking at the fundus image to store the fundus image in the storage device 61.

[0037]

As described above, according to the present invention, the second image pickup device having the light receiving area smaller than the light receiving area of the first image pickup device is provided. Therefore, the magnification is changed without using the variable power optical system. Therefore, it is not necessary to increase the working distance between the examiner and the subject.

Further, since the second image pickup device is provided so as to be movable to an arbitrary position within the plane orthogonal to the optical axis of the image pickup optical system, if the second image pickup device is moved to the desired position, the desired position is raised. Since it is possible to display images at a magnification, it is not necessary to guide the visual axis by the fixation target to position the desired part on the optical axis of the imaging optical system as in the conventional case. Will be released from the hassle of.

Further, even when photographing a position far away from the center position of the fundus, the second image pickup element is connected to the portion by tilting the visual axis so that the portion falls within the photographing field of the photographing optical system. Since it may be moved to the image position, the inclination of the visual axis may be small, and the subject does not feel any pain.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing the arrangement of an optical system of a fundus camera according to the present invention,

FIG. 2 is a configuration diagram showing a moving mechanism of a CCD,

FIG. 3 is a block diagram showing the configuration of a control system for moving the X and Y stages,

FIG. 4 is an explanatory diagram of an eye to be inspected,

FIG. 5 is an explanatory diagram of an image displayed on a monitor.

[Explanation of symbols]

 1 Photographic Optical System 8 Mirror 10 First Image Sensor 11 Second Image Sensor 64 Solenoid

Claims (3)

[Claims] 1. An ophthalmologic image pickup apparatus comprising an image pickup optical system for photographing an eye to be inspected, wherein the image pickup optical system has a first image pickup element and a light receiving area smaller than a light receiving area of the first image pickup element. An ophthalmology characterized by comprising a second image sensor having a pixel density higher than that of the first image sensor, and a switching means for performing image capturing by either the first image sensor or the second image sensor. Imaging device. 2. The ophthalmologic photographing apparatus according to claim 1, wherein the second image pickup device is provided so as to be movable to an arbitrary position in a plane orthogonal to the optical axis of the image pickup optical system. 3. The ophthalmology according to claim 2, further comprising a monitor optical system for observing the eye to be inspected on a monitor, and a display means for displaying the position of the second image pickup device together with the eye image on the monitor. Imaging device.