JPH0698860A - Optical system for projecting target of fixation - Google Patents

Abstract

PURPOSE:To provide a fixation target projection optical system which enables better ensuring of a fixation of an eye to be inspected by allowing the projecting of the target of fixation according to conditions of a subject. CONSTITUTION:When a luminous flux emitted from a fixation light source 2 is projected to the eyeground Er of an eye E to be inspected as a fixation target, the color of the fixation target is changed optionally by controlling the light emission conditions of an LED of the fixation light source 2 to be projected to the eyeground Er. Besides, the size or shape of the fixation target is altered with a pattern member 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixation target projection optics for projecting a fixation target, which is disposed inside a main body of an ophthalmologic machine and is fixed to the eye to guide the eye, onto the fundus of the eye. It is related to the system.

[0002]

2. Description of the Related Art Conventionally, in various ophthalmic machines, a fixation target projection optical system for projecting a fixation target onto the fundus to guide the eye to be inspected during alignment and photographing and prevent a slight movement of the eye is provided inside the main body. Some are arranged.

This fixation target projection optical system is constructed as a fixation target which the eye to be inspected fixes and projects a light flux emitted from a fixation light source such as an LED onto the fundus of the eye to be inspected.

[0004]

By the way, in the fixation target projection optical system configured as described above, since the fixation targets of the same shape and the same color are projected on the fundus of the eye to be examined, for example, color blindness. It may not be possible to fixate the fixation target depending on the subject's condition such as age, disability such as cataract, age, etc., so the fixation state of the eye to be examined is not stable and it takes time for alignment operation etc. However, there are inconveniences such as obtaining a desired photographing result.

The present invention has been made in view of the above circumstances, and it is possible to project a fixation target according to the condition of the subject, and to make the fixation of the eye to be examined more reliable. An object is to provide a fixation target projection optical system.

[0006]

In order to achieve the object, the invention described in claim 1 is a fixation target projection optics for projecting a light beam emitted from a fixation light source as a fixation target onto a fundus of an eye to be examined. The gist of the system is to provide a color changing means for changing the color of the fixation target projected onto the fundus.

The invention according to claim 2 is a fixation target projection optical system for projecting a light beam emitted from a fixation light source as a fixation target onto a fundus of an eye to be inspected. A pattern changing means for changing the shape is provided.

[0008]

In the above-mentioned structure according to claim 1,
When the luminous flux emitted from the fixation light source is projected as a fixation target onto the fundus of the eye to be inspected, the color of the fixation target is changed to an arbitrary color by the color changing means and projected onto the fundus.

According to the second aspect of the invention,
When projecting the light flux emitted from the fixation light source as a fixation target onto the fundus of the eye to be inspected, the pattern changing means changes the size or shape of the fixation target.

[0010]

Embodiments of the fixation target projection optical system of the present invention will now be described with reference to the drawings.

In FIG. 1, reference numeral 1 is a fixation target projection optical system for projecting a fixation target onto the fundus Er of the eye E to be examined.

This fixation target projection optical system comprises a fixation light source (color changing means) 2, a lens 3, a pattern member (pattern changing means) 4, and an objective lens 5. The fixation light source 2 is provided at a position conjugate with the fundus Er.

The fixation light source 2 used here is composed of, for example, LEDs 2a, 2b and 2c which independently emit R (red), G (green) and B (blue) colors. The LEDs 2a, 2b, 2c are controlled by a controller (not shown) so that the LEDs 2a, 2b, 2c are emitted individually or in combination.

As shown in FIG. 2, the pattern member 4 includes a disk-shaped panel 4a and a shaft 4b for rotating the panel 4a. The panel 4a has a large number of patterns P1, P2 ... P16 set in a predetermined shape and size.
Is provided.

The patterns P1, P2 ... P16 are formed by a light-shielding film or the like which shields light except for the openings formed in the panel 4a or the shape portion to be projected. Further, the patterns P1, P2, ..., P16 are selectively controlled by the above-described control device so that a pattern according to the condition of the subject such as an obstacle or age is located on the optical axis O.

For example, if the eye E to be inspected is an old one, it is round and large, if the eye E to be inspected is a young person, it is small and concentrated in the center, and the eye E to be examined is a child or an infant. If it is a thing, a thing having a characteristic shape is selected.

The shapes and sizes of the patterns P1, P2 ... P16, and the number thereof are not particularly limited.

Further, the control device for controlling the fixation light source 2 and the pattern member 4 is based on, for example, eye data such as an ID card or a chart set for each subject (or for each eye). Light emission of LEDs 2a, 2b, 2c and pattern P
1, P2 ... P16 are selected. Also, the LED that emitted light
The light amount of 2a, 2b, 2c is controlled to change the color of the fixation chart. The color of the fixation table can be adjusted by manual operation, or the light amounts of the LEDs 2a, 2b, 2c can be automatically changed according to the areas of the selected patterns P1, P2 ... P16. .

In the above structure, the diffused light emitted from the fixation light source 2 is collimated by the lens 3 and guided to the pattern member 4. At this time, when the diffused light emitted from the fixation light source 2 is a combination of the LEDs 2a, 2b, 2c, the emitted LEDs 2a, 2b, 2c are emitted.
According to the amount of light of these, these will be in the color-mixed state.

Then, only the portions of the patterns P1, P2 ... P16 corresponding to the pattern shape located on the optical axis O pass through in a mixed state, and then are projected onto the fundus Er of the eye E through the objective lens 5. It

By fixing the fixation target, the subject can suppress the fine movement of the eye E and can shorten the alignment operation time and photograph a desired part. .

By the way, in the above-mentioned embodiment, the one using the LEDs 2a, 2b, 2c of three colors of R, G and B is disclosed, but it is not limited to the above-mentioned embodiment such as using a full color LED. Absent.

Further, as shown in FIG. 3, the diffused light emitted from the fixation light source 2 is condensed on the optical fiber 7 by the condensing lens 6, and the luminous flux mixed by the optical fiber 7 is formed on the lens 3 and the pattern. Eye E through the member 4 and the objective lens 5
It is also possible to lead to the fundus Er of the eye.

[0024]

As described above, according to the fixation target projection optical system of the present invention, the fixation target according to the condition of the subject is projected to ensure the fixation of the eye to be examined. It can be anything.

[Brief description of drawings]

FIG. 1 is an optical explanatory diagram showing a fixation target projection optical system of the present invention.

FIG. 2 is also a front view of the pattern member.

FIG. 3 is an optical explanatory view showing a second embodiment of the fixation target projection optical system of the present invention.

[Explanation of symbols]

 1 ... Fixation target projection optical system 2 ... Fixation light source (color changing means) 4 ... Pattern member (pattern changing means)

Claims (2)

[Claims] 1. A fixation target projection optical system for projecting a light beam emitted from a fixation light source as a fixation target onto the fundus of an eye to be inspected, wherein a color change for changing the color of the fixation target as projected onto the fundus. A fixation target projection optical system characterized by comprising means. 2. A fixation target projection optical system for projecting a light beam emitted from a fixation light source as a fixation target onto the fundus of an eye to be inspected, wherein pattern changing means for changing the size or shape of the fixation target is provided. A fixation target projection optical system.