JPH07124111A - Optometry device - Google Patents

Abstract

(57) [Summary] [Purpose] Perform accurate alignment by omitting subtle adjustments during alignment. A light flux reflected by the cornea Ec of the eye E to be examined by the alignment light source 20 is received by the four-leaf photoelectric elements 26 and 27 as a cornea reflected light flux image Pc. Further, the cornea reflected light flux is imaged by the television camera 15 as a cornea reflected light flux image Pc together with the anterior segment image, and is displayed on an external television monitor. The examiner roughly adjusts the position of the device while observing the television monitor. In a computer (not shown), based on the alignment detection signals from the photoelectric elements 26 and 27,
The position of the measuring unit 9 is finely adjusted. When the computer confirms the end of the alignment, the intraocular pressure measurement is started.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In conventional optometers such as tonometers and autorefractometers, an operating rod is operated to tertiaryly move an apparatus main body on a slide table to perform alignment.

[0003]

However, in the conventional apparatus, since the position adjustment requires delicate adjustment, the operator's individual difference is likely to occur and the measured value becomes unstable.
In addition, the movable part of the device becomes large and the structure becomes complicated.

The object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide an optometry apparatus that can reduce the size of a movable part and can easily and accurately perform positioning.

[0005]

SUMMARY OF THE INVENTION An eye examination apparatus according to the present invention for achieving the above-mentioned object includes a forehead support which is provided in a housing so as to be adjustable in the optical axis direction, and an eye examination apparatus which is provided in a direction from the optical axis direction. It is characterized by having an image pickup means for picking up an image of the anterior segment of the eye, and an optometry optical system for photoelectrically detecting a light flux from the eye to be inspected and driving it based on the detection signal.

[0006]

In the optometry apparatus having the above structure, the examiner observes the anterior segment of the subject's eye and adjusts the position of the forehead rest in the optical axis direction. After that, the position of the optometry optical system is automatically adjusted with respect to the subject's eye based on the detection signal of the light flux from the subject's eye.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments. FIG. 1 is a side view in which the present invention is applied to a non-contact tonometer, and FIG. 2 is an optical layout diagram of a measurement unit. A chin rest 2 is provided on the lower front portion of the housing 1, and a forehead rest 3 is provided on the upper front portion thereof. The chin rest 2 is moved up and down by the rotation of the chin rest adjustment knob 4 on the right side face, Is the forehead support adjustment knob 5 on the top
It is designed to move back and forth by rotating. Furthermore,
A measurement switch 6 for starting the measurement, a printer 7 for printing the measurement result on a sheet, and a television monitor 8 are provided on the upper surface of the housing 1. A measuring unit 9 having a lens, a television camera, and the like built therein is provided in the housing 1, and a driving unit 10 is attached to the bottom surface of the measuring unit 9 to move the measuring unit 9 in the X, Y, and Z directions. Is being done.

As shown in FIG. 2, the optical path inside the measuring section 9 is
A nozzle 11 facing the eye E to be inspected is provided on the chamber 1 on O1.
It is attached to 2. Behind the chamber 12, a prism 13 having a reflecting surface 13a on the optical path O1, a lens 1
4. The TV camera 15 is sequentially arranged, and the output of the TV camera 15 is connected to the TV monitor 8.
A flexible tube 16 is connected to the chamber 12 so that air from a pressurizing means 17 including a piston, a cylinder and the like can flow into the chamber 12. A lens 18, a dichroic mirror 19 and an alignment light source 20 are arranged on the optical path in the incident direction to the reflecting surface 13a of the prism 13, and a fixation lamp 21 is arranged on the optical path in the incident direction of the dichroic mirror 19. There is.

On the two optical paths O2 and O3 which are symmetrically inclined with respect to the optical path O1, there are four-leaf photoelectric elements 26 and 27 composed of lenses 22, 23, dichroic mirrors 24, 25 and four light receiving elements. A measurement light source 28 is arranged on the optical path of the dichroic mirror 24 in the incident direction, and a photoelectric sensor 29 is arranged on the optical path of the dichroic mirror 25 in the reflecting direction. Here, the outputs of the photoelectric elements 26 and 27 and the photoelectric sensor 29 are connected to a computer (not shown) that controls the measuring unit 9. Further, since the pressurizing means 17 is relatively heavy, it is provided outside the measuring section 9 so as not to hinder the movement of the measuring section 9.

At the time of measurement, first, the head of the subject S is fixed by the chin rest 2 and the forehead rest 3, and the alignment light source 2
0, the anterior segment is observed while the fixation lamp 21 is turned on. The reflected light flux at the anterior segment due to the anterior segment illumination light is stored in the chamber 12,
The image passes through the prism 13 and the lens 14 and is captured by the television camera 15 as the anterior segment image Pf, and is displayed on the television monitor 8. The light flux from the fixation lamp 21 is the dichroic mirror 1.
9, reflected by the reflecting surface 13a of the prism 13,
The light passes through the chamber 12 and the nozzle 11 and is projected onto the fundus Er of the eye E to be examined, and is observed by the eye E as a fixation target inside the nozzle 11.

The light flux from the alignment light source 20 passes through the dichroic mirror 19 and the lens 18, is reflected by the reflecting surface 13a of the prism 13, passes through the chamber 12 and the nozzle 11, and is a virtual image on the cornea Ec of the eye E to be examined. Image as Pc '. The reflected light flux here passes through the lenses 22 and 23 and the dichroic mirrors 24 and 25 on the optical paths O2 and O3, and is converted into a corneal reflected light flux image Pc as shown in FIGS. , 27, respectively, and the alignment detection signals from the photoelectric elements 26, 27 are output to the computer. Further, the reflected light beam from the cornea Ec is transmitted through the optical path O1.
Passing through the upper chamber 12, prism 13 and lens 14,
The cornea reflected light flux image Pc is also picked up by the TV camera 15 and displayed on the TV monitor 8. The examiner roughly adjusts the position of the device while observing the television monitor 8.

FIG. 4 shows the screen of the television monitor 8 during observation of the anterior segment of the eye. The corneal reflected light flux image Pc is projected as a bright spot on the pupil part of the anterior segment image Pf, and the alignment mark AM is also projected. The examiner instructs the subject S to fixate the fixation target by the fixation target 21, and turns the chin rest adjustment knob 4 so that the pupil part is at the same height as the alignment mark AM. Two
Adjust the height of. Then, the forehead support 3 is moved back and forth by the forehead support adjusting knob 5 so that the anterior segment image Pf is in focus, and the distance between the eye E to be inspected and the housing 1 is adjusted. After completion of this rough adjustment, the measurement switch 6 is pushed.

The computer finely adjusts the measuring unit 9 according to the input of the measuring switch 6 to perform accurate alignment. In the computer, the received light amounts of the four light receiving elements of the photoelectric elements 26 and 27 are compared based on the alignment detection signals from the four-leaf photoelectric elements 26 and 27, and the corneal reflected light flux image Pc is the central portion of the photoelectric elements 26 and 27. The drive signal of the drive means 10 is generated so that the light receiving amounts of the light are received by each of the photoelectric elements 26 and 27 and the received light amounts of the elements are equal.

Based on this drive signal, the drive means 10 adjusts the position of the measuring unit 9 in the XYZ space in the up / down, left / right, and front / rear directions. That is, the corneal reflected light flux image Pc is in focus, the drive signal of the drive means 10 is created based on the alignment detection signals of the photoelectric elements 26 and 27, and the measuring unit 9 is moved. When the computer determines that the alignment is completed, the measurement light source 28 is turned on and the eye E
Air is jetted to the cornea Ec of.

The luminous flux from the measuring light source 28 on the optical path O2 is
The light is reflected by the dichroic mirror 24, passes through the lens 22, and is projected onto the cornea of the eye E to be inspected. The reflected light flux here passes through the lens 23 on the optical path O3, is reflected by the dichroic mirror 25, and is received by the photoelectric sensor 29. Light reception signals from the photoelectric sensor 29 are sequentially captured by the computer. The air compressed by the pressurizing means 17 flows into the chamber 12 through the flexible tube 16 and is sprayed by the nozzle 11 onto the cornea Ec of the eye E to be inspected,
Applanate Ec. When the cornea Ec is deformed into a predetermined shape, since the cornea Ec and the photoelectric sensor 29 have a conjugate relationship, the received light signal of the photoelectric sensor 29 is output to the computer as a sharpened peak signal. When this peak signal is detected by the computer, the air pressure at this point is measured and converted into the intraocular pressure.

Further, the computer sequentially takes in the alignment detection signals from the four-leaf photoelectric elements 26 and 27 during the measurement, analyzes the position of the corneal reflected light flux image Pc, monitors the movement of the eye E, and the measuring unit 9 The position of is corrected at any time.
Furthermore, it is possible to detect a change in the intensity of the alignment detection signals from the photoelectric elements 26 and 27 and monitor the open eyelid state of the eye E to be examined.

When the measurement of the eye E to be inspected is completed, the measuring section 9 is moved in the X direction to face the other eye. At this time, in order to avoid collision with the bridge of the nose, the measuring unit 9 once returns in the Z direction and then moves in the X direction. When the alignment state is confirmed by the computer, the measurement is automatically started for the other eye. The measurement result is printed on paper by the measurement printer 7 and also displayed on the television monitor 8. Here, the eye E to be inspected is switched by moving the measuring unit 9 in the X direction. However, the chin rest 2 is allowed to move left and right, and the head of the eye E to be moved left and right with respect to the housing 1. Then, the eye E to be inspected may be switched. In this case, since the measuring unit 9 can be moved two-dimensionally from the outside, the coarse adjustment of the device can be quickly performed manually when observing the anterior segment.

In this embodiment, the examiner operates on the side surface of the housing 1. Therefore, if the examinee S is likely to close his eyelids, he can open them with his hands. Further, since the distance between the eye E to be inspected and the apparatus can be always checked, the operation can be performed safely even if the working distance becomes short. At this time, it is convenient that the television monitor 8 can be rotated so that the screen is directed to the examiner.

In this embodiment, the four-leaf photoelectric elements 26, 2
Although the alignment state is determined based on the cornea reflected light flux image Pc of No. 7, the corneal reflected light flux image Pc of the image pickup element of the television camera 15 can be used. Since the corneal reflected light flux image Pc here has high brightness, the computer captures the video signal of the central portion of the image pickup element of the television camera 15, determines the position and blurring state of the corneal reflected light flux image Pc, and drives the driving means 10.
Drive signals can be created.

Although this embodiment is applied to a tonometer, it can also be applied to an autorefractometer and a fundus camera. When applied to an eye refractometer, it is also preferable to monitor whether the eye E to be inspected is covered by the anterior segment observation means or whether the eye E is sufficiently dilated. In addition, when applied to a fundus camera, the television camera 15 monitors the alignment.
It is advisable to use the video signal of the peripheral edge of the pupil image on the image pickup device. Based on this video signal, the aiming of the pupil of the anterior segment image Pf and the eccentricity from the optical path O1 are determined, and the measuring unit 9 is adjusted in the Z direction and the XY plane.

[0021]

As described above, the optometry apparatus according to the present invention detects the light flux from the eye to be examined, and based on this signal,
Since the position of the optometry optical system is automatically adjusted, the annoyance of performing a delicate operation during the position adjustment is released, and even an inexperienced person can easily perform the operation.

[Brief description of drawings]

FIG. 1 is a side view.

FIG. 2 is an optical layout diagram of a measurement unit.

FIG. 3 is an explanatory diagram when a cornea reflected light flux image is received by a four-leaf photoelectric device.

FIG. 4 is an explanatory diagram when observing the anterior segment of the television monitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Jaw rest 3 Forehead support 6 Measurement switch 7 Printer 9 Measuring section 11 Nozzle 15 TV camera 20 Light source for alignment 21 Fixation lamp 26, 27 Four-leaf photoelectric element 28 Light source for measurement 29 Photoelectric sensor

Claims (3)

[Claims] 1. A forehead support provided on a housing so as to be adjustable in the optical axis direction, and an optometry optical system for photoelectrically detecting a light beam from an eye to be inspected and driving based on the detection signal. An optometry device. 2. The optometry apparatus according to claim 1, further comprising imaging means for imaging the anterior segment of the eye to be examined from the optical axis direction. 3. The optometry apparatus according to claim 1, further comprising a chin rest that is vertically adjustable.