JP3176669B2 - Optometry device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optometric apparatus for objectively measuring the refractive power of an eye to be inspected, and to an apparatus for measuring the refractive power when a target at a finite distance is presented to the eye. It is.

[0002]

2. Description of the Related Art As a device for objectively measuring the refractive power of an eye to be inspected, an index for measurement is projected onto the fundus of the eye to be inspected, and an optical system is adjusted so that the target image becomes a predetermined state. 2. Description of the Related Art There are known an apparatus for measuring a refractive power and an apparatus for detecting a fundus reflected light as a measurement index with a light receiving element and calculating the refractive power of the eye to be inspected based on the detection result. Such an apparatus has a structure in which a fixation point cannot be presented, or a structure in which a measurement optical axis cannot rotate with respect to a so-called chin rest for fixing an eye to be examined.

[0003]

By the way, when the subject's eye is fixed at a finite distance, the subject's eye rotates around the rotation point of the eyeball and the visual axis moves. When the target is presented to the eye to be examined and the eye is adjusted, convergence, and miosis are attempted to objectively measure the refractive power, the measurement optical axis and the visual axis cannot be matched. There is a problem that the refractive power of the fovea of the optometry cannot be measured objectively. Further, there is a disadvantage that the measurement light beam is easily kicked by the iris due to the angle generated between the visual axis and the measurement optical axis.

[0004] It is an object of the present invention to provide an optometric apparatus for accurately measuring the objective refractive power of the central fovea of an eye while the eye to be inspected is gazing at a target located at a finite position. .

[0005]

To achieve the above object, the optometry apparatus of the present invention has the following configuration. (1) A target at almost the same finite distance to both eyes
An optometry device with a target presenting means to be presented to the eye to be examined
The chin rest to keep the position of both eyes constant,
By projecting the target on the fundus of the fixed eye and detecting the projected target image
A measuring optical system for measuring a refractive index;
Corresponding to the angle of convergence of the eye to be measured when recognizing a target
The measurement optics so that the measurement axis passes through the center of rotation of the eye to be measured.
And a measuring optical system rotating means for rotating the system .

(2) The optotype is located at the same distance from both eyes.
The target presenting means moving on the moving axis and the eye to be examined
Specifying means for specifying the distance between them, and specifying by the specifying means
Driving means for moving the target based on the distance obtained.
Optometry device to keep the positions of both eyes constant
Chin rest for measurement and transmission of visible light obliquely placed in front of the eyes
Has an optical element that reflects light and measures through the optical element
The target image is projected on the fundus of the eye to be measured and the target image projected on the fundus
Optical system for detecting the refractive index of the subject's eye
The measurement is performed in accordance with the convergence angle of the eye to be measured at the determined optometry distance.
The measurement axis of the constant optical system is rotated with respect to the movement axis, and the measurement is performed.
The measurement axis of the constant optical system and the visual axis of the eye to be measured are defined by the optical element.
And a measuring optical system rotating means for making the subject coincide.
It is characterized by

(3) In the optometry apparatus of (2), further
A rotation axis for rotating the measurement optical system with respect to the subject.
A moving means is provided for moving on the extension of the left and right central axes of the target.
It is characterized by

[0008]

[0009]

[0010]

[0011]

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of the apparatus of the present embodiment as viewed from the lateral direction, and a part of a mechanism for rotating a measurement optical system is a sectional view. Reference numeral 1 denotes a dichroic mirror (photomirror) that transmits visible light and reflects near-infrared measurement light, and its optical characteristics are selected in relation to the wavelength of the measurement light beam. With the disadvantage that the field of view is slightly darker, a beam splitter can be used instead of a dichroic mirror. The subject's eye 2 gazes at the target 3 through the dichroic mirror 1. The target 3 is suspended from a rack 4 supported by a bearing (not shown). The rack 4 moves in the axial direction by rotation of a pinion 6 fixed to a rotation shaft of a motor 5.
The subject moves on an axis equidistant from both eyes of the subject. Target 3
The height of the eye is adjusted to the height of the subject's eye by moving the chair up and down (a mechanism for raising and lowering the column described below may be provided).
A mechanism for driving the target 3 is supported by a support (not shown). Reference numeral 7 denotes a housing for housing a measurement optical system and the like for automatic measurement of refractive power. The housing 7 holds the mirror 8 and the dichroic mirror 1. The measurement light uses infrared light, and after being reflected by the mirror 8 and the dichroic mirror 1 in front of the measurement optical unit, enters the eye to be examined.

Reference numeral 9 denotes a rotation mechanism for making the measurement optical axis coincide with the visual axis when the visual target moves. Reference numeral 10 denotes a rotation center of the rotation mechanism 9. Reference numeral 11 denotes a motor for moving the rotation center 10 so as to match the center of the target.
A pinion 12 is attached to the center of rotation of. The rack 13 is attached to the rail 14 and the linear motion unit 1
Since 5 moves directly on the rail 14, the rotation center 10 moves in the axial direction of the rail by the rotation of the motor 11 (see FIG. 2). 15a shows a bearing. The linear motion unit 16 also has a structure that linearly moves on the rail 17, but the rack 18 is not attached to the rail 17, and is free in the linear motion direction with respect to the linear motion unit 16 by the slide bearing 19. (See FIG. 3). For this reason, even if the rotation center 10 of the rotation mechanism moves, the base 2
The position of 1 does not change.

Reference numeral 22 denotes a positioning mechanism for positioning the measuring optical system and the eye to be inspected. Reference numeral 23 denotes a vertical movement knob. When the vertical movement knob 23 is rotated, a gear 26 rotates via a gear 24 and a belt 25, and a vertical movement screw 27 is rotated.
Rotates to move the housing 7 in the vertical direction. 28 indicates a steady rest, 29 indicates a bearing. Target 3
When the height is adjusted by a switch signal, the height may be automatically adjusted by this signal. In addition, the positioning in the front-back direction is performed by moving the joystick knob 30 back and forth while watching the anterior eye image of the television monitor (not shown), and sliding the sliding board 31 with respect to the sliding board 32 and moving the housing 7. The linear motion unit 34 integrated with the moving table 33 to be placed is linearly moved along the rail 35 to perform the operation.
36 is a spherical bearing. The positioning in the left-right direction is performed by operating the joystick knob 30 to rotate the measurement optical unit to the rotation center of the rotation mechanism. In addition,
The rotation angle is regulated within a certain range so that the dichroic mirror-1 does not collide with the subject's eye or chin rest. The minimum restriction angle is determined in consideration of the position of the dichroic mirror-1 and the moving range of the target.

The operation of the apparatus of the embodiment having the above configuration will be described. FIG. 4 is a block diagram illustrating the operation of the rotation mechanism unit 9. The microcomputer 41 drives the motor 5 via the motor drive circuit 42 in response to a signal from the target distance setting switch 40 provided by the examiner, and moves the target 3 to the set position. The microcomputer 41 drives the motor 11 via the motor drive circuit 43, and the rotation of the motor 11 causes the linear motion unit 15 to make the rotation center 10 of the rotation mechanism 9 coaxial with the target center. It moves directly on the rail 14 to the position.
The examiner operates the joystick knob 30 to rotate the measurement optical unit around the rotation center of the rotation mechanism, and matches the visual axis direction of the subject's eye with the measurement optical axis (see FIG. 5). The housing 7 has a structure that rotates about a rotation mechanism 9 that is coaxial with the center of the target. The optotype 4 has a structure that can be moved to an arbitrary position by an examiner's operation, and the rotation mechanism of the measuring optical section also has a structure that always moves coaxially with the center of the optotype independently of the measuring optical section. In addition, the visual axis of the subject's eye and the measurement optical axis can always be matched.

The rotation of the rotation mechanism 9 as described above has been described in connection with the manual operation by operating the joystick 30. However, the present invention is not limited to this. It may drive an arcuate gear attached to the moving unit 16, and if this is controlled by a microcomputer, it can be automated in accordance with the movement of the target 3. In this case, it is convenient to use a potentiometer or the like for detecting the rotation angle.

[0017]

According to the present invention, it is possible to objectively measure the refractive power of a subject's eye gazing at a target located at a finite distance with high accuracy and with the subject's eye being naturally converged. . Therefore, the importance increases with the increase of the elderly population, and the examiner can easily and accurately measure the accommodation power and the near point with the examinee in a more natural state.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a partial cross section of an optometer according to an embodiment viewed from the side.

FIG. 2 is a cross-sectional view of FIG.

FIG. 3 is a sectional view taken along a line B in FIG. 1;

FIG. 4 is a block diagram illustrating the operation of the rotation mechanism.

FIG. 5 is an explanatory diagram illustrating an operation of a measurement optical unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dichroic mirror 2 Eye to be examined 3 Optotype 7 Housing 9 Rotation mechanism part 22 Positioning mechanism

Claims (3)

(57) [Claims] 1. At substantially the same finite distance to both eyes
An optometric device with optotype presenting means for presenting optotypes to the subject's eye
A chin rest to keep the position of both eyes constant,
Projects an index on the fundus of the eye to be measured and detects the projected index image
Measuring optical system for measuring the refractive index
Corresponding to the angle of convergence of the eye to be measured when recognizing a target
The measurement axis so that the measurement axis passes through the center of rotation of the eye to be measured.
A measuring optical system rotating means for rotating the optical system.
Optometric apparatus according to claim and. 2. A movement in which the target is at substantially the same distance as both eyes.
An optotype presenting means moving on the axis and a distance from the eye to be examined
Specifying means for specifying the separation, and
Driving means for moving the target based on a distance.
In an optometry device, the position of both eyes must be kept constant.
Transmits visible light obliquely in front of the eyes and the chin rest, and
Having an optical element that emits light, and a measurement index through the optical element.
Detects the target image projected on the fundus of the eye to be measured and projected on the fundus
Measurement optical system for measuring the refractive index of the eye to be examined, and
The measurement optics corresponding to the convergence angle of the eye to be measured at the optometry distance
Rotating the measuring axis of the system with respect to the moving axis,
The measurement axis of the system and the visual axis of the eye to be measured are more
A measuring optical system rotating means for matching by the examiner.
Optometric apparatus according to claim and. 3. The optometric apparatus according to claim 2, further comprising:
The rotation axis for rotating the measurement optical system with respect to the subject
Moving means to move on the extension of the left and right central axes
An optometric apparatus , characterized in that: