JPH0228885Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is a non-mydriatic fundus camera, especially an optical system for observing and photographing the eye to be examined, and an optical axis that intersects with the optical axis of the optical system. The present invention relates to a non-mydriatic retinal camera equipped with an illumination optical system disposed in the camera.

(Prior technology) Conventionally, the fundus of the eye to be examined is irradiated with infrared light, the reflected light is received by an infrared imaging device through an observation optical system, and focusing operations and visual field determination are performed using a TV monitor. This is because it does not require the use of mydriatic eye drops for the pupils, so it is becoming very useful as an alignment method for fundus photography in the preliminary stage of a detailed fundus examination. It's called a camera.

However, conventionally, TV monitor devices have been installed in the vicinity of the non-mydriatic retinal camera body and are connected via cable to the TV camera device that includes an image sensor built into the camera body. In order to view the TV monitor, the examiner, who is facing the subject with a non-mydriatic fundus camera in between, must take his/her eyes away from the camera's operation section and turn toward the TV monitor device placed near the camera. Since the TV monitor is viewed face-to-face, consideration must be given to the location of the TV monitor, which not only takes up wasted space, but also is cumbersome to operate, making it easy to make mistakes and waste time. It also came with some drawbacks.

In order to solve these problems,
As seen in No. 132703, an optical path switching mechanism for switching the illumination optical path is provided at a fixed point on the optical axis of the illumination optical system, and an observation illumination optical system including a light source and an infrared filter is connected to another light source. The photographic illumination optical system including the above-mentioned fixed point is arranged so as to cross and distribute to the left and right when viewed from the optical axis of the objective lens, and a space is left below the focusing lens of the observation photographic optical system, and a space is provided there. A non-mydriatic fundus camera configured with a TV monitor device has been developed.

(Problems to be Solved by the Present Invention) According to the content described in the above-mentioned Utility Model Application No. 60-132703, the photographing illumination light is introduced into the ring slit by the optical path switching mechanism only during photographing. Therefore, the reflection direction of the movable mirror is mechanically switched by operating the shutter button, but the shooting operation must be performed in an extremely short period of time to avoid losing the shutter chance, and the rapid movement of the movable mirror is required. This operation not only tends to generate vibrations and make the optical axis of the illumination light unstable, but also has the possibility of adversely affecting the optical image.

Furthermore, sufficient consideration had to be given to issues such as the noise generated by these operations and mechanical durability.

The object of the present invention is to provide a non-mydriatic fundus camera that is easy to operate and has excellent durability, without emitting vibrations or operating noises as described above.

(Means for Solving the Problems) In order to solve these problems, the present invention provides an optical system for observing and photographing the subject's eye, and an optical axis that intersects with the optical axis L1 of the optical system. In a non-mydriatic fundus camera equipped with an illumination optical system disposed on L2, observation illumination light is reflected adjacent to a ring slit 22 disposed on optical axis L2 of the illumination optical system, and photographing illumination light is reflected. Transparent beam splitter 21
a is installed diagonally, and the optical axis L is a direction in which the observation illumination light is reflected in one of the left and right horizontal directions from the intersection with the optical axis L2.
Concave mirror 1 along the optical axis L2a from one end on 2a
7. A lamp 18, a condenser lens 20, and an infrared filter 19 are disposed, and the beam splitter 21a is arranged in a direction in which the photographing illumination light is transmitted and is on an extension of the optical axis L2 of the photographing illumination optical system. A total reflection mirror 21b is obliquely installed adjacent to the beam splitter 21a, and the optical axis L2b whose optical axis L2 is bent by the total reflection mirror 21b is the optical axis L2.
2a and opposite to the optical axis L2a, and from one end on the optical axis L2b to the optical axis L2b.
A concave mirror 26, a flash discharge tube 27, and a condenser lens 28 are arranged along the lamp 1.
8 and the flash discharge tube 27 illuminate the subject's eye through the ring slit 22.

(Function) According to such a configuration, there is no need for a mechanism for switching between observation illumination light and photography illumination light, and no problematic vibrations or operational noises are generated.

(Example) The details of the present invention will be explained below with reference to the drawings.

FIG. 1 is a layout diagram illustrating an embodiment of the present invention, and FIG. 2 is a view taken along the line A--A in FIG. 1.

In the figure, the reference numeral 1 indicates a non-mydriatic fundus camera, and the observation/photographing optical device 2 has an objective lens 6 obliquely installed along the optical axis L1 at a position facing the eye E to be examined. A perforated mirror 7, a focusing lens 8, an imaging lens 9, and a movable mirror 10 movably supported by a shaft 10a are rotatable in the direction of the arrow and are normally arranged at the inclined position shown by the solid line.
Further, behind the movable mirror 10, a film bag 11 loaded with a film F is installed.

The movable mirror 1 is moved upwardly along the optical axis L3 from the intersection of the optical axis L1 and the movable mirror 10 during photographing.
0 retreat position 10', field lens 12,
A mirror 13 is installed obliquely with respect to the optical axis L3, and an image of the fundus of the examinee's eye is created using infrared light along the optical axis L4, which is bent from the intersection of the mirror 13 and the optical axis L3 and extends in a direction approaching the examinee's eye E. An imaging lens 14 is provided to form an image on the image sensor 15.

Therefore, on the upper side of the optical device 2 mentioned above,
It is optically engaged with an integrally provided TV camera device 4.

Further, the illumination optical system device 3 integrally provided below the optical device 2 has an optical axis L2 extending downward from the intersection of the perforated mirror 7 incorporated in the optical device 2 and the optical axis L1. Above, a relay lens 25 is disposed close to the perforated mirror 7, and further below it is a signboard 24 having a black dot, a relay lens 23, a ring slit 22 having a ring-shaped light transmitting part, and obliquely disposed with respect to the optical axis L2. A beam splitter 21a and a total reflection mirror 21b, which is also provided obliquely, are arranged.

Instead of having a certain reflectance and transmittance over most of the light wavelength range, the beam splitter 21a reflects infrared light in the invisible range and transmits most of the light in the visible range. It is possible to use a wavelength-selective filter made of a multilayer interference thin film or the like.

As shown in FIG. 1, from the intersection point P with the optical axis L2 of the beam splitter 21a mentioned above, on the optical axis L2a extending to the left in the figure, infrared light is emitted from the direction near the beam splitter 21a. an infrared filter 19 that transmits only light, a condenser lens 20,
A lamp 18 and a concave mirror 17 are provided. With the above concave mirror 17, lamp 18, lens 20, filter 19, and beam splitter 21a,
It constitutes an observation illumination light device 29.

Also, on the optical axis L2b extending from the intersection Q with the optical axis L2 of the total reflection mirror 21b to the right in FIG. A concave mirror 26 is provided. The above concave mirror 26 and discharge tube 2
7, the lens 28, and the mirror 21b constitute an illumination light device 30 for photographing.

In other words, in FIG. 2, the observation illumination light device 29 is placed on the left side with the optical axis L2 in between, and the photography illumination light device 30 is placed on the right side, facing each other. Of course, the photographing illumination light device 30 may be placed on the left side, and the observation illumination light device 29 may be placed on the right side.

When the lamp 18 is turned on through a power supply device (not shown), the light is converged by the lens 20 together with the light reflected by the concave mirror 17, and
It passes through the filter 19, becomes only infrared light, is reflected by the beam splitter 21a, is focused on the ring slit 22, passes through it, passes through the relay lens 23, and is then reflected on the surface of the objective lens for observation and photography. Black dot signboard 2 to remove harmful light
4. They are arranged so as to pass through the relay lens 25 and reach the mirror portion of the perforated mirror 7.

On the other hand, when the flash discharge tube 27 is excited by a device (not shown) to emit light, the light is converged along the optical axis L2b by the condenser lens 28 along with the light reflected by the concave mirror 26, and then by the total reflection mirror 21b. It is reflected, transmitted through the beam splitter 21a, focused on the ring slit 22, passes through it, passes through the relay lens 23, passes through the signboard 24 and relay lens 25, and reaches the mirror portion of the perforated mirror 7. They are arranged as follows. (Fig. 2) In Fig. 1, in the space below the inspection/photographing optical device 2 and adjacent to the rear side of the illumination optical system device 3, there is a TV monitor with a built-in CRT 16 of a TV receiver. A device 5 is disposed integrally with the optical device 2 and the illumination optical system device 3.

Next, the operation of this embodiment configured as above will be explained.

First, turn on the main switch of the electrical system (not shown), and at the same time turn on the lamp 18.
is turned on, and the fundus camera 1 is placed in an operational standby mode.

Next, the objective lens 6 is brought to face the corneal surface of the eye E to be examined.

The light emitted from the lamp 18 passes through the lens 20 and the filter 1 together with the light reflected by the concave mirror 17.
9 and becomes only infrared light, half mirror 2
It is reflected by 1a and illuminates the ring slit 22.

After passing through the ring slit 22, the light passes through the relay lens 23, the signboard 24, and the relay lens 25, is reflected by the mirror portion of the perforated mirror 7, is focused by the objective lens 6 onto the cornea of the eye E, and then is transmitted to the crystalline lens. and illuminates the retinal surface of the fundus of the eye.

The light reflected from the fundus passes through the objective lens 6, the hole of the perforated mirror 7, the focusing lens 8, and the imaging lens 9, changes its optical path by the movable mirror 10, travels along the optical axis L3, and passes through the field lens 1.
After the image is once formed near the lower surface of 2, it passes through the lens 12, is reflected by the mirror 13, and reaches the image sensor 15 by the imaging lens 14 along the optical axis L4.

The infrared light image of the fundus that has reached the image sensor 15 is converted by a conversion device (not shown) built into the TV camera device 4 or the TV monitor device 5.
It is displayed as a visible image on the CRT 16.

The operator adjusts the focusing lens 8 using a focusing knob (not shown) while looking at the image, and adjusts a mount etc. that allows alignment of the camera (not shown) to the subject's eye to obtain the best image formation. The state, that is, the focus of the fundus, and the best screen state, that is, the photographic field of view of the fundus, are adjusted.

Subsequently, by operating a shutter button (not shown), the movable mirror 10 is rotated to its retracted position 10', and the flash discharge tube 27 is energized to emit light.

The emitted light, together with the light reflected by the concave mirror 26, passes through the lens 28, is reflected by the total reflection mirror 21b, passes through the beam splitter 21a along the optical axis L2, and irradiates the ring slit 22.

The light transmitted through the ring slit 22 passes through the perforated mirror 7 and the objective lens 6, and illuminates the fundus of the eye E, as in the case of the infrared light described above.

The light reflected from the fundus passes through the objective lens 6, the hole in the perforated mirror 7, the focusing lens 8, the imaging lens 9, and is loaded into the film bag 11, as in the case described above. The image is formed on the photosensitive surface of the film F.

Another embodiment of the present invention is shown in FIG. 3, which shows the layout of its main parts.

In this embodiment, the beam splitter surface 2
1a', since the prism 21 is constructed by joining two individual prism blocks, the two surfaces 21a' and 21b' are integrally fixed, and when assembling, each surface is There is no need to adjust the mounting angle, etc., and the unit structure is easy to assemble and adjust, and the structure is stable with little deviation of the optical axis.

The rest of the configuration is the same as the previous embodiment, and when the lamp 18 is turned on, the light is directed along the optical axis L2a to a point on the beam splitter surface 21a' of the prism 21.
It is reflected by P' and illuminates the ring slit 22.

When the flash discharge tube 27 emits light, the light is reflected by the total reflection surface 21b' of the prism 21, passes through the beam splitter surface 21a', and irradiates the ring slit 22.

The state after passing through the ring slit 22 is as follows.
Since this is the same as the case explained in the previous embodiment, the explanation will be omitted.

(Effects of the invention) As explained above, according to the invention, there is a beam splitter or a wavelength selector that reflects observation illumination light and transmits photographing illumination light adjacent to the ring slit arranged on the optical axis of the illumination optical system. A concave mirror, a lamp, a condenser lens, and an infrared filter are arranged along the optical axis from one end on the optical axis in the direction in which the observation illumination light is reflected. A total reflection mirror is provided obliquely adjacent to the beam splitter in the direction in which the light is transmitted and is an extension of the optical axis of the illumination optical system, and the optical axis is bent by the total reflection mirror. A concave mirror, a flash discharge tube,
In addition to arranging the condenser lenses, the light emitted from the lamp and flash discharge tube illuminates the eye to be examined through the ring slit, so the illumination device is able to move from observation to photography using the conventional method. Since there are no moving parts like those in , it does not generate vibrations or operating noises, improves durability, and is easy to assemble and adjust, making it an extremely practical idea.

[Brief explanation of the drawing]

FIG. 1 is a layout diagram illustrating an embodiment of the present invention;
2 is a view taken along the line A--A in FIG. 1, and FIG. 3 is a layout diagram showing only the main parts of another embodiment of the present invention. 17, 26...Concave mirror, 18...Lamp, 19
...Infrared filter, 21 ... Prism, 21a
...beam splitter, 21b...total reflection mirror.

Claims (1)

[Claims for Utility Model Registration] 1. A non-mydriatic device comprising an optical system for observing and photographing the eye to be examined, and an illumination optical system disposed on the optical axis L2 intersecting the optical axis L1 of the optical system. In the type fundus camera, a beam splitter 21a that reflects the observation illumination light and transmits the photographic illumination light is installed obliquely adjacent to the ring slit 22 disposed on the optical axis L2 of the illumination optical system, so that the beam splitter 21a reflects the observation illumination light and transmits the photographing illumination light. From one end on the optical axis L2a in the direction of reflecting the observation illumination light in one of the left and right horizontal directions from the intersection point to the optical axis L2a
A concave mirror 17, a lamp 18, a condenser lens 20, and an infrared filter 19 are arranged along the
Further, a total reflection mirror 21b is obliquely installed adjacent to the beam splitter 21a in the direction in which the photographing illumination light of the beam splitter 21a is transmitted and on an extension of the optical axis L2 of the photographing illumination optical system. The optical axis L2 is the total reflection mirror 21b.
The optical axis L2b bent by the optical axis L2b is set so as to be substantially parallel to the optical axis L2a and opposite the optical axis L2a, and the concave mirror 26, flash discharge tube 27, A non-mydriatic fundus camera characterized in that a condenser lens 28 is arranged and the light emitted from the lamp 18 and the flash discharge tube 27 illuminates the eye to be examined through the ring slit 22. 2. A non-mydriatic fundus camera according to claim 1, wherein the beam splitter 21a and the total reflection mirror 21b are constructed of an integral optical member 21 formed by prism bonding. 3. Claims for registration of a utility model characterized in that the beam splitter 21a is constituted by a wavelength-selective filter such as a multilayer interference thin film that reflects infrared light in the invisible range and transmits most of the light in the visible range. The non-mydriatic fundus camera according to item 1 or 2.