JP3190083B2 - Near measurement mechanism of subjective 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 a near-type measurement of a subjective optometry apparatus.
The present invention relates to a near-measurement mechanism for a subjective optometry apparatus which measures a near point distance by a subjective optometry apparatus to obtain an addition power.

[0002]

2. Description of the Related Art Conventionally, in an optometry apparatus that performs comprehensive visual function measurement, a subjective measurement apparatus and an objective measurement apparatus are installed on one table, and measurement work from an interview to a wearing test can be performed in one place. It is built as a simple system. In ophthalmologists and optician stores, visual function measurement with this type of optometry device
There are objective measurement for measuring data in a rough range, and subjective measurement performed by placing lenses of various powers in front of the subject based on the objectively measured data.

[0003] Incidentally, according to subjective measurement performed using a target, accommodation power, which is one of the measures for evaluating the function of the eye, can be measured. There are two methods for measuring this adjusting force, a push-up method and a minus lens method. In the push-up method, an optotype is approached to a limit point in front of the eye where the eye can be clearly seen, a position at which the outline is blurred is determined, and a near point distance is measured. In the minus lens method, the target is 40
Present at the cm position and add a minus lens in front of the subject until it is blurred. In either case, it is necessary to move the presentation position of the optotype or to switch the optotype or the lens power. A device for performing this kind of subjective measurement is conventionally known as a near point distance measuring device. Note that the near point distance refers to a distance to an external object that can be imaged on the retina when trying to look closer by adjusting the eyeball.

[0004] For example, in the near point distance measuring device disclosed in Japanese Patent Application Laid-Open No. Sho 62-14828 or Japanese Utility Model Application Laid-Open No. 3-16903, or a subjective optometry system,
At the same time that the optotype is moved by the motor, the optotype is manually moved near the near point by providing a manual handle or the like.
Even if the measurer does not stand up from the chair, the optotype can be rotated or the optotype can be moved in the direction of the midline of the subject. In these devices, measures are taken to facilitate the optometric operation for determining the addition power by subjective measurement and to improve the measurement accuracy of the accommodation power.

[0005]

However, the calculation for obtaining the adjusting force from the measured data in a predetermined calculation procedure requires time and effort. In particular, when creating a spectacle lens, it is necessary to input a near-work target distance based on near-work distance information requested by the subject through an interview with the subject.

[0006] In order to determine the addition power desired by the subject based on the measurement result of the accommodation power and the near-distance target distance, it is necessary to accurately evaluate the measured data. For this reason, even when the target position and the target are switched, there is a problem that it takes time to determine a required addition power and it is difficult to secure measurement accuracy.

The present invention has been made in view of the above points, and is a self-conscious type which can measure comprehensive visual functions and visual acuity and can determine the addition power with high accuracy and efficiency. An object of the present invention is to provide a near-measurement mechanism of an optometric apparatus.

[0008]

[0009]

According to the present invention, in order to solve the above-mentioned problems, a visual target or a visual function is measured by presenting an optotype to a person to be measured.
Measuring head for subjective optometry with switchable optical system
In the near measurement mechanism of the subjective optometric apparatus having
There are multiple near-measurement mechanisms that can be switched by driving a motor.
Presenting means for providing a short- distance target having a short-distance target, moving means for moving the presenting means, and moving the presenting means with a finger.
Command control means for controlling the presentation position of the visual target, the distance between the short-range visual target positioned by the moving means and the person to be measured, and the addition power based on the specified near-work target distance. Calculating means for calculating the near distance
The target charts are displayed graphically and this graphic display
Instruction function to select a near vision target from and to instruct input, near work
A function to set the target distance, a function to set the near vision target position,
Display for near measurement with the function of displaying the addition power
A subjective optometric apparatus characterized by having an operation screen
A near-site measurement mechanism is provided.

[0010]

[0011]

The present invention presents a short-distance target in front of the subject's eyes. Further, the moving means moves the presenting means so as to approach the limit position where the subject can clearly see. After being positioned by the moving means, the near point distance is measured from the distance between the short distance target and the subject. This measured value is converted into a diopter value, the adjusting power is determined by the calculating means, and the addition power is further obtained. Also, the display
On the operation screen, the near vision target group corresponding to
And display the near target from this graphic display.
Select and instruct input, set the near work target distance,
Set the mark position and display the addition power.

[0012]

[0013]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a state in which the optotype presenting apparatus 1 is attached to the near rod 2. The optotype presenting apparatus 1 includes a plurality of optotypes, and includes an optotype driving unit 3 and an optotype control unit 4. The distance rod (cm) and the diopter value (D) are displayed on the side surface of the near rod 2, and the rod 2 is detachably fixed to the mounting unit 6 at the tip of the measuring arm 5 by screws 7. The attachment unit 6 is attached to the tip of the measurement arm 5 so as to be rotatable around a vertical axis in the figure. Note that the measurement arm unit 5 is supported by a head support unit (see FIG. 2) described later.

The optotype driving unit 3 of the optotype presenting apparatus 1 has a built-in drive motor, and slides along the near rod 2 within a predetermined range to move the optotype control unit 4 of the near rod 2. Positioning at a predetermined position. The measurement head unit 8 includes a lens unit 9 whose position can be adjusted to the distance between the left and right pupils (PD), and a PD control circuit (FIG. 3) for controlling the PD.
(See FIG. 4). The measurement head 8 is suspended below the tip of the measurement arm 5, and the lens unit 9 is
The built-in lens system is switched to arrange a lens having a desired refractive index in front of the subject's eyes. Also,
The PD unit 10 of the measuring head unit 8 is provided with a PD control board 11, which outputs a target selection signal or a target position command signal converted into an optical signal.
A light emitting element 11a such as a D circuit is disposed. Further, the optotype control section 4 of the optotype presenting apparatus 1 is provided with a sensor circuit 12 for receiving an optical signal from the light emitting element 11a.

The target control unit 4 includes a control board 13 on which a control circuit for controlling the target is arranged. The control board 13 controls the rotation of an optotype motor, which will be described later, based on the optotype selection signal received by the sensor circuit 12 of the optotype control section 4. Thereby, the optotype control unit 4 is switched to the optotype selected from the plurality of optotypes. The drive motor of the optotype driving section 3 is controlled based on the optotype position command signal, and the optotype presenting apparatus 1 is positioned along the near rod 2.

FIG. 2 is a front view showing the overall configuration of the subjective optometry system including the optotype presenting apparatus 1. The measurement arm unit 5 is supported by the head support unit 14 so as to be vertically movable and rotatable in a horizontal plane. The head support portion 14 is provided upright on the right side of the optometry table 15 in which a display is built. A movable table 16 is slidably movable in the left-right direction on the optometry table 15.
Is provided. For example, an objective optometry apparatus or the like can be placed on the movable table 16, and the objective table can be slid to the central position of the optometry table 15 before the subjective measurement to perform the objective measurement. Below the optometry table 15,
A base 17 incorporating a main controller is arranged. The main controller controls the entire subjective optometry system as described later. Note that FIG.
In the optotype presenting apparatus 1, the optotype control section 4 is folded with respect to the optotype driving section 3 so that the optotype control section 4 is parallel to the near rod 2. In addition, the near rod 2 itself is also moved from the position of use shown in FIG.
Has been rotated to the position (retracted state) in parallel with.

In FIG. 2, the person to be measured is an optometry table 1.
Sit on the front side of the device, facing the measurer sitting in front of 5. The near rod 2 is rotated about 90 ° toward the near side on the optometry table 15 based on a command from the measurer,
The state is switched to the use state of FIG. Furthermore, the positions of the left and right lens units 9a and 9b in the left and right directions are adjusted so that the measurement windows 9c and 9d match the pupil position of the subject. In addition, the signal window 1 provided in the PD unit 10
A target selection signal converted into an optical signal and a position command of the target plate are output from 1b. Thereby, a predetermined target is presented to the person to be measured by the target presenting apparatus 1, and visual acuity or visual function can be measured.

FIG. 3 is a block diagram showing the configuration of a control circuit for controlling the subjective optometry system.
In the left and right lens units 9a and 9b, a desired lens is arranged in the measurement windows 9c and 9d by a control circuit that controls the rotation position of the built-in lens disk. Therefore, when the power is turned on, it is necessary to read the rotational position of the optical disk. Here, the left lens unit 9a is controlled from an optical sensor 61 such as a spherical lens sensor, an astigmatism lens sensor, a switching sensor, an auto-cross sensor, and a prism sensor arranged on the optical disc, on the left lens unit 9a. The respective rotational position signals are output to the circuit 62. The control circuit 62 includes a drive circuit and an interface circuit, and the drive circuit is connected to motors 63 such as a spherical lens motor, an astigmatic lens motor, a switching motor, an auto-cross motor, and a prism motor, each of which is constituted by a pulse motor. Is done. The control circuit 62 is connected to a main control circuit 65 via a PD control circuit 64 disposed in the PD unit 10.
It is connected to the. These motors 63 are driven at a constant speed by command data input from a main control circuit 65 built in the base 17 via an interface circuit. The figure shows a control block for only the left lens unit 9a. However, the control circuit of the right lens unit 9b having the same configuration is also connected to the PD control circuit 64. The main control circuit 65 is connected to an input device 66 such as a mouse that works in conjunction with an EL display arranged on a measurement table, and outputs command data for rotating the lens disk based on a command from a measurer.

FIG. 4 is a block diagram showing the configuration of an optotype control circuit for controlling the optotype presenting apparatus and its peripheral circuits. The PD control circuit 64 is an optotype selecting means that converts the optotype selection signal into an optical signal and outputs the optical signal to the optotype control circuit 67. The PD control circuit 64 is connected to the main control circuit 65 by the RS232C interface 64 a and the CPU 6.
4b, a ROM 64c, a RAM 64d, an output-side interface circuit 64e, and the like. Here, the light emitting circuit 11a, a motor for PD control (not shown), and the like are connected to the interface circuit 64e. The optotype control circuit 67 includes the light receiving circuit 12, the optical sensor 38a of the drive unit 3, and the optotype plate 46.
Input circuit 67a, CPU 67b, ROM 67c to which the origin sensor 51 and the DIP switch 52 are connected.
The output circuit 6 includes a RAM 67d and an output circuit 67e.
7e includes a drive motor 31, a target motor 47, and an illumination lamp 4.
8 and a buzzer 68 are connected.

As described above, the optotype presenting apparatus 1 receives the optotype selection signal as an optical signal from the PD control circuit 64 formed separately from the optotype presenting apparatus 1. A wire that hinders movement of the optotype control unit 4 that drives the thirteen is unnecessary. Therefore, the drive motor 31 of the optotype driving section 3 is controlled based on the optotype position command signal received by the optotype control section 4, and the optotype presenting apparatus 1
Can be stopped at a predetermined position of the near bar 2 and the visual function can be measured while switching the visual acuity target of the optotype plate 46.

FIG. 5 is a diagram showing an example of an input screen displayed on a display built in the optometry table 15. This input screen shows a state where the cross-line target has been selected. The measurement using the cross line optotype is performed simultaneously with both eyes in front of the cross cylinder, and the cross line optotype is presented at the near work target distance. For the display, a flat graphic display means such as an electroluminescence (EL) display or a liquid crystal display is used. The selection of the target type is performed by moving a cursor (not shown) displayed on the display with a mouse and designating the target from a target group 90 displayed graphically. A command corresponding to the selected optotype is given to the optotype presenting apparatus 1 as an optical signal from the light emitting element 11a of the measuring head section 8, and the optotype plate rotates by a predetermined angle.

FIG. 6 shows an example of an input operation screen for near measurement displayed on the display. The near work target distance in the near measurement can also be set by selecting the distance setting arrow 91 with the cursor displayed on the display. The optotype presenting apparatus 1 can be moved along the near rod 2 by placing the cursor on the position of the plus sign (+) or minus sign (-) of the arrow 91 and operating the mouse a predetermined number of times. The short-distance target distance is displayed in the center part 92 of the screen, and the measurer follows the guidance in the lower part 93 of the screen.
When the subject is asked, "If the target is blurred, press the button. ]. When the start button 94 is pressed, the short-distance target presenting device moves at an appropriate speed along the near rod, and the subject measures the stop signal by the patient key at the position where the target is blurred. input. At this time, the addition power is calculated based on the position of the short-distance target presenting apparatus and the near-distance target distance displayed in the center part 92 of the screen, and the value is displayed in the left and right areas 95 and 96 at the top of the screen. You.

Next, a description will be given of a method of determining the addition power by which the near-point distance is measured by the above-mentioned subjective optometry apparatus to obtain the addition power. In the addition measurement in near measurement,
The short-distance target presenting device is moved in front of the eye of the subject, and the target is brought close to the limit position (adjustable near point) at which visible observation is possible.
This near point distance is subjectively measured when the subject responds to the measurer or the optometry apparatus in some way. In the optometry apparatus, a value obtained by converting the near point distance into a diopter value is calculated as accommodation power, and the addition power of the subject is determined.

In general, the procedure for measuring the addition power is classified into the following four types. The first is a method in which, when the eye to be measured is not presbyopia, the addition by the lens unit 9 is set to zero and the near point is measured only once using a predetermined target.

The second is a method of performing a plurality of near-point measurements when the eye to be measured is not presbyopia. Third
Is a method in which, when the measurement eye of the subject is presbyopia, the provisional addition is set by the lens unit 9 and the near point measurement is performed only once using a predetermined target.

A fourth method is to perform a plurality of near-point measurements when the subject's eye to be measured is presbyopia. this house,
The first and second cases are cases where the near measurement can be performed with the measuring eye of the person to be measured or only with the accommodation power of the glasses already worn from the measurement result in the distance measurement. , The third and fourth cases are assumed to be special cases.
Therefore, only the third and fourth cases will be described below.

First, after the distance power is measured by the distance measurement, the diopter value set in the lens unit 9 is regarded as a temporary addition power, and the true addition power is measured on the input operation screen shown in FIG. .

FIG. 7 is a flowchart for explaining the flow of the calculation for determining the addition power. In the figure, the numerical value following S indicates the step number, and the setting in each step,
Alternatively, the selection operation is performed by a measurer clicking a cursor on the operation screen with a mouse, and other calculations are executed by a processor built in the main control circuit 65.

[S1] The eye to be measured is determined by blocking the lens disk of the left eye or the right eye of the subject. [S2] The optotype to be used is determined by rotating the optotype plate of the short-distance optotype presenting apparatus and selecting the smallest optotype (minimum readable optotype) among optotypes readable by the subject. I do. [S3] The short-range target presenting device is moved to start the accommodation force measurement test. The start position of the optotype is usually set at 40 cm (0.4 m) in front of the subject, and the short-distance target presenting device approaches the subject at an appropriate speed along the near rod. [S4] When the visual target is blurred, a "stop" signal is input to the optometry apparatus. In this case, the measurer inputs the reaction of the person to be measured from the input operation screen. Further, the patient may operate the patient key. [S5] When the stop signal is input, the short-distance target presenting device stops. The main body of the optometry apparatus automatically reads the near point distance. [S6] The temporary accommodation power D1 converted into a diopter value is calculated from the following equation, using the value of the near point distance at which the short distance target presenting apparatus stops as the measured near point L (m).

D1 = 1 / L The provisional accommodation force D1 is a value obtained by adding the provisional addition power to the true accommodation force. [S7] The true accommodation power D is calculated by subtracting the diopter value set on the lens disc of the eye to be measured, that is, the temporary addition, from the calculated temporary accommodation power D1. [S8] The addition power is calculated by substituting the true accommodation power D calculated in step S7 and the near work target distance M of the subject into the following equation.

X = (1 / M) −D × α (where α is 乃至 to ／) (1) where the coefficient value α is the true accommodation power D of the subject. Is selected according to For example, the adjusting force D is 2.5 (diopter)
In the above case, it is preferable to use 2/3, and in the case of 2.5 (diopter) or less, 1/2 is used.

FIG. 8 is a flowchart for explaining the flow of calculation in the case where the addition power is determined by performing a plurality of measurements of accommodation power. In FIG. 8, the procedure (steps 13 to 17) from when the provisional adjustment force D1 is calculated in steps S3 to S6 in FIG. 7 is different, and the procedures before and after that are the same as those in FIG.

[S11] The eye to be measured is determined. [S12] The target to be used is determined. [S13] The short distance target presenting device is moved. [S14-S17] The averaged adjusting force is determined. That is, when the visual target is first blurred, a stop signal is input to the optometry apparatus. When a stop signal is input,
The short-range target presenting device stops. The main body of the optometry apparatus automatically reads the first near point distance L1. This near point distance L1
Is used as a measurement near point L (m), a temporary accommodation force D1 converted to a diopter value is calculated in the same manner as in step S6,
Then, a command to reverse the short-range target presenting apparatus is given.

When the short-distance target presenting device moves in the opposite direction, that is, in a direction in which the target is moved away from the subject, the subject outputs a stop signal when the target is clearly seen again. Input to the optometer. When the stop signal is input for the second time, the short distance target presenting device stops and the second near point distance L2 is automatically read into the optometry apparatus main body. Then, similarly, the second provisional adjustment force D2 is calculated.

Further, the moving direction of the optotype is repeatedly inverted, and n values of accommodation power are determined. By determining a plurality of temporary accommodation forces D1, D2,..., An average accommodation force Dm (= ΣDi / n) is determined.

[S18] From the calculated temporary adjustment force Dm,
The true accommodation power D is calculated by subtracting the diopter value set on the lens disk of the eye to be measured, ie, the provisional addition. [S19] True adjustment force D calculated in step S18
Then, the addition distance is calculated by substituting the target work distance M of the subject and the near work target distance M into the above equation (1).

In the above description, it is assumed that the accommodation force measurement is executed by the input operation screen shown in FIG. 6 and the input means such as a mouse. However, other than this, for example, by using the screen of FIG. 5, it is also possible to input the same operation command and move the short-distance target presenting apparatus, and in any case, the distance information is automatically displayed. And the accommodation power can be measured. Therefore, according to the subjective optometry apparatus of the present invention, the addition power can be obtained by a simple procedure based on the near point distance measured a plurality of times.

[0038]

As described above, according to the present invention, it is possible to obtain the distance information from the short-distance target presenting apparatus and automatically calculate the accommodation power. Therefore, the burden on the measurer performing the optometry work is reduced, and the addition power is determined with high accuracy.
It can be performed efficiently. In addition, since the addition power can be obtained by a simple procedure based on the perimeter distance measured a plurality of times, even an operator who does not have sufficient knowledge about the near vision measurement can reliably determine the addition power. can do.

[Brief description of the drawings]

FIG. 1 is a side view showing a state in which an optotype presenting apparatus of the present invention is attached to a near rod.

FIG. 2 is a front view showing the overall configuration of the subjective optometry system of the present invention.

FIG. 3 is a block diagram illustrating a configuration of a control circuit.

FIG. 4 is a block diagram showing a configuration of a target control circuit and its peripheral circuits.

FIG. 5 is a diagram illustrating an example of an input screen displayed on a display.

FIG. 6 is a diagram showing an example of an input screen for near measurement displayed on a display.

FIG. 7 is a flowchart illustrating an example of a measurement procedure.

FIG. 8 is a flowchart showing another example of the measurement procedure.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 optotype presenting device 2 near rod 8 measuring head 15 optometry table 64 PD control circuit 72 remote controller

Continuation of the front page (56) References JP-A-63-135127 (JP, A) JP-A-59-95030 (JP, A) JP-A-59-44327 (JP, A) , U) Hikaru Hei 3-16903 (JP, U) Japan Eye Glasses College, “Eyeglass Optics Handbook” 2nd edition (1972-2078), Kanehara Idemitsu Co., p. 82-84 (58) Field surveyed (Int. Cl. ⁷ , DB name) A61B 3/00-3/16

Claims (3)

(57) [Claims] A visual target or visual function is measured by presenting an optotype to a person to be measured, and is driven by a motor in front of the person to be measured.
Measuring head for subjective optometry with switchable optical system
In the near measurement mechanism of the subjective optometry apparatus, the near measurement mechanism has a plurality of short distance targets that can be switched by driving a motor.
A short-distance target presenting means, a moving means for moving the presenting means, and a command for moving the presenting means to control a presenting position of the visual target.
A command control unit that, a calculation means for calculating a power addition based on the near-work purposes distances distance, and designated with the near visual target and the subject positioned by said moving means, for measurement near Graphic display of the corresponding near vision target group,
Select a near target from this graphic display and specify input.
Indicating function, function to set distance for near work, and near use
Equipped with a function to set the target position and a function to display the addition power
And a display operation screen for near vision measurement.
Structure. 2. A method for presenting a visual target to a person to be measured for visual acuity or visual acuity.
Measure the function and drive the motor in front of the subject
Measuring head for subjective optometry with switchable optical system
In the near measuring mechanism of the subjective optometric apparatus having a near measuring mechanism, the near measuring mechanism measures the addition power from the measured near point distance.
An optotype that has a function to calculate and allows the subject to see clearly with the provisional addition set.
To change the presentation position of the selected optotype to reduce the near point distance.
Measure and measure based on the near point distance and the provisional addition.
The true accommodation power (D) of the person is calculated, and the accommodation power (D) and the near-work target distance (M) are calculated by the following equation.
By substituting into (1), X = (1 / M) −D × α (where α is 乃至 to ／) (1) Addition power of the subject (X) The near-measurement mechanism of the subjective optometric apparatus , which calculates 3. The method according to claim 3, wherein the near-point distance is measured a plurality of times and the average is measured.
The adjusted accommodation force (Dm) is obtained, and is obtained by the above equation (1).
3. The method according to claim 2, wherein the additional power is calculated by using
A near-use measurement mechanism for a subjective optometry device.