JPH10276983A - Proximal distance meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to easily and quickly measure a distance to make optometry be smoothly carried out, by equipping an ultrasonic distance meter to measure the distance from a position of a subject's eye to a proximal optotype. SOLUTION: This ultrasonic distance meter 4 comprises a transmitting element 41 to transmit an ultrasonic wave, a receiving element 42 to receive the ultrasonic wave, a pulse transmitting circuit 43 to transmit a prescribed pulse signal to the transmitting element 41, a receiving circuit 44 to convert a received signal from the receiving element 42 to a prescribed pulse signal, a control circuit 45 to give and receive those transmitted and received pulses to transmit signals corresponding to those pulse intervals, a counter circuit 46 to receive a signal from the control circuit 45 to convert the signal to a signal corresponding to time or distance, and a reference signal generating circuit 47 to generate the reference signal thereof. Accordingly, the time from an ultrasonic wave is transmitted from the transmitting element 41 to the ultrasonic wave is reflected by a proximal optotype 2, a reflective body, is measured to obtain the distance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a near distance measuring apparatus which can easily and quickly measure a near distance to facilitate an optometry operation.

[0002]

2. Description of the Related Art Conventionally, a near vision chart apparatus has been used for near vision measurement. In this measurement, the distance between the eye of the eye to be examined and the near vision chart apparatus is measured. It is essential to ask. For this reason, conventionally, a method has been generally used in which a scale indicating a distance is provided on a support rod which movably supports the near vision chart apparatus, and the number of scales moved by the near vision chart apparatus is read.

[0003] Further, as a near vision chart device, a device having a mechanism for automatically switching an optotype or a moving mechanism for enabling the entire device to automatically move on a support rod has been proposed (for example, a special visual acuity table). See JP-A-5-176890).
In this type of apparatus, the moving distance is automatically measured using a moving mechanism.

[0004]

However, the method of reading the number of graduations has the advantage that the mechanism is simple. However, first, the operation of reading the graduations is complicated and a reading error occurs. There is a risk.
In addition, since the read values must be input through the main control device of the optometer, the work is complicated, and there is a risk that an input error may occur.

[0005] The automatic apparatus system does not involve the complication of work or the possibility of erroneous reading or input unlike the graduation reading system. However, the mechanism is complicated and expensive, and conversely the operation is difficult. It was undeniable that it was not always easy and difficult to handle.

The present invention has been made under the above-mentioned background, and can automatically measure a near distance.
An object of the present invention is to provide an inexpensive near-distance measuring device that does not require complicated reading operation, does not cause a reading error or an input error, and is extremely simple, easy to handle, and inexpensive.

[0007]

In order to solve the above-mentioned problems, a first aspect of the present invention provides a near-infrared eye tester for measuring the distance between the position of the eye of an eye to be examined and a distance visual acuity chart apparatus. In a distance measuring method for use, an ultrasonic distance measuring device for measuring a distance between the subjective ophthalmoscope and the near vision chart device is provided.

According to a second aspect of the present invention, in the near vision chart apparatus, one end is fixed to a front part of the subjective ophthalmoscope and the other end is directed to a position where the near vision chart is arranged at the time of near vision measurement. A distance measuring device, which is movably supported by a support rod which is extended.

[0009]

FIG. 1 is a perspective view showing the configuration of a near distance measuring apparatus according to an embodiment of the present invention, FIG. 2 is a circuit block diagram of an ultrasonic distance measuring apparatus, and FIG. 3 shows the entire configuration of an optometric apparatus. FIG. 4 is a perspective view, FIG. 4 is a partially enlarged view showing a state where the near vision chart device is attached to a support rod, and FIG. 5 is a front view of the near vision chart device. Hereinafter, an optometry apparatus according to an embodiment will be described with reference to these drawings.

As shown in FIGS. 1 and 3, the near distance measuring device of this embodiment has an ultrasonic distance measuring device 4 attached to a support mechanism 11 of a subjective optometer 1, and a near vision chart device. 2 is movably supported by a support rod 3 having one end fixed to a coupling shaft 15 of the subjective optometer 1.

The subjective optometer 1 is supported by a connecting shaft 15 on a support arm 14 which is a tip of a support 101 attached to an optometry table 100. A support mechanism 11 is fixed to a lower end of the coupling shaft 15, and the left eye lens unit 1a and the right eye lens unit 1b are supported by the support mechanism 11 so as to be position-adjustable. The support mechanism 11 automatically adjusts the left and right distances (PD) of the left-eye lens unit 1a and the right-eye lens unit 1b, and adjusts the up / down adjustment knob 12 and the radiation adjustment (tilt adjustment) knob 13 respectively. It has a mechanism for adjusting the relative vertical position and tilt angle of the two lens units by adjusting the rotation.
Left eye lens unit 1a and right eye lens unit 1
b indicates that a large number of optometry lenses are freely selected and arranged in the measurement window in which the eye of the subject is arranged.

The ultrasonic distance measuring device 4 is provided at the center of the front surface of the support mechanism 11, and is arranged so that the transmitting and receiving surfaces of the transmitting element 41 and the receiving element 42 face the near vision chart apparatus 2. .

As shown in FIG. 2, the ultrasonic distance measuring device 4 converts a predetermined pulse signal into a driving signal by the transmitting element 41 for transmitting the ultrasonic wave, the receiving element 42 for receiving the ultrasonic wave, and the transmitting element 41. A pulse transmission circuit 43, a reception circuit 44 for converting a reception signal from the reception element 42 into a predetermined pulse signal, a control circuit 45 for transmitting and receiving these transmission and reception pulses and transmitting a signal corresponding to the pulse interval,
The counter circuit 46 receives a signal from the control circuit 45 and converts the signal into a signal corresponding to time or distance, and a reference pulse generating circuit 47 for generating a reference signal for the counter circuit 46. Thereby, the ultrasonic wave transmitted from the transmission element 41 is reflected by the near vision chart device 2 which is a reflector, and the reception element 42
Is measured until the distance is detected to determine the distance. Although not shown, the distance measurement is performed by a command from an input device of the input device of the main control device 5. The signal of the distance measured in this way is sent to the main control device 5 or the like, where a predetermined process is performed. That is, for example, it is possible to send the measured near distance and the near point distance to the main control device 1 to calculate the addition degree in real time.

As shown in FIGS. 4 and 5, in the near vision table apparatus 2, a near vision table board 21 on which various optotypes are posted is rotatably stored in a storage case 22. Numeral 22 is supported by a moving member 24 via a rotation support portion 26. The moving member 24 has a slide hole 25 that fits into the support bar 3 and slides on the support bar 3. The rotation support portion 26 is configured so that the storage case 22 can be folded along the support bar 3.

According to the above-described embodiment, the near distance is automatically measured only by the input operation from the main control device 5, and the result is automatically taken in to calculate the addition and the like in real time. it can. Therefore, there can be obtained an excellent advantage that the reading operation is not complicated, there is no possibility that a reading error or an input error occurs, and the configuration can be made extremely simple, easy to handle, and inexpensive.

In the above-described embodiment, an example in which the ultrasonic distance measuring device 4 is provided in the subjective optometry apparatus 1 has been described, but the ultrasonic distance measuring device 4 is provided in the near vision chart device 2. You may.

[0017]

As described above in detail, the present invention relates to a near distance measuring apparatus for measuring the distance between the position of the eye of an examinee's eye and the distance visual acuity apparatus of a subjective ophthalmoscope. An ultrasonic distance measuring device that measures the distance between both the instrument and the near vision chart device is provided, which makes it possible to automatically measure the near distance and complicate reading work. An object of the present invention is to provide an inexpensive near distance measuring device which is free from reading errors or input errors, and which is extremely simple, easy to handle, and inexpensive.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a near distance measuring apparatus according to an embodiment of the present invention.

FIG. 2 is a circuit block diagram of the ultrasonic distance measuring device.

FIG. 3 is a perspective view showing an overall configuration of the optometry apparatus.

FIG. 4 is a partially enlarged view showing a state where the near vision chart device is attached to a support rod.

FIG. 5 is a front view of the near vision chart device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Subjective ophthalmoscope 2 ... Near vision chart device 3 ... Support rod 4 ... Ultrasonic distance measuring device 5 ... Main control device 41 ... Ultrasonic transmitting element 42 ... Ultrasonic receiving element

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazumasa Takahashi 2-7-5 Nakaochiai, Shinjuku-ku, Tokyo Hoya Co., Ltd.

Claims (2)

[Claims] 1. A near distance measuring device for measuring a distance between a position of an eye of a subject's eye of a subjective ophthalmoscope and a near visual acuity device, wherein the subjective ophthalmic device or the near visual acuity device An ultrasonic distance measuring device for measuring the distance between the two. 2. The near vision chart device has a support fixed at one end to a front part of the subjective ophthalmoscope and the other end extended toward a position where the near vision chart is arranged at the time of near vision measurement. A near distance measuring device which is movably supported by a rod.