JPH0418568Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a subjective optometry device that can measure distance and near refractive power.

[Prior Art] In a subjective optometrist, it is necessary to align the optical axis of the measurement lens with the visual axis of the subject. Therefore, in order to measure the refractive power of the subject's eye in near vision, first adjust the interpupillary distance so that the distance between the left and right measurement lenses matches the distance between the eyes in far vision, and then As described, by rotating the tilting lever using a cam mechanism, the optical axis of the measurement lens is made parallel to the visual axis of the subject's near vision, and the left and right measurement lenses are The spacing between the units was corrected to align the optical axis with the visual axis.

[Problems with the prior art] However, it is difficult to make the optical axis of the measurement lens of the conventional device parallel to the visual axis of the subject's near vision and to correct the distance between the left and right measurement lens units. The problem was that the mechanism realized through operation was extremely complex.

An object of the present invention is to provide a simple tilting mechanism in view of the problems of the conventional device described above.

Another object of the present invention is to realize a mechanism for vertically moving a measuring lens unit with a simple mechanism.

[Structure of the invention] In order to achieve the above object, the present invention provides a subjective optometry device for measuring distance and near refractive power, in which the right eye measurement lens unit and the left eye measurement lens unit are tilted. A drive motor for changing the distance between the two lens units, and a control means for controlling the drive motor. It is characterized by doing.

[Example] Hereinafter, one example of the present invention will be described based on the drawings.

FIG. 1 shows a suspension part of a measuring lens unit of a subjective optometry apparatus according to the present invention.

1 is a hanging plate for fixing a measuring lens unit (not shown), and a shaft 2 is fixed to the hanging plate 1. The shaft 2 is inserted into the hole 4 of the slide base 3 and is rotatable. Also, the female screw 5 of shaft 2
By screwing the male screw 7 of the vertical movement knob 6 into the vertical movement knob 6, it is possible to move the vertical movement up and down.

The slide base 3 is slidable in the axial direction of a fixed guide 8, and a drive motor 9 for sliding is fixed together with the fixed guide 8 to a fixed bracket (not shown).

The drive motor 9 has screws 1 in different directions.
0 and 11 are connected and engaged with the female threads of the slide base 3, the two slide bases 3 are moved in opposite directions by the drive motor 9.

12 is a drive motor for tilting, and in this embodiment, a stepping motor whose rotational position can be accurately memorized and controlled is used. The tilting drive motor is fixed to a fixed bracket (not shown), and worms 14 and 15 having different torsional directions are fixed on the rotating shaft 13 thereof. The wheels 16, 17 that engage with these worms are fixed to rotatable shafts 18, 19, and eccentric shafts 20, 21 and bearings 22, 23 are arranged at the lower ends of the wheels 16, 17, which are connected to the grooves 24 in the hanging plate 1. , 25. For this reason, the tilting drive motor 1
2 rotates the hanging plates 1 in opposite directions. 26 is a micro switch for detecting the initial position of the slide table 3. Reference numeral 27 denotes a micro switch for detecting the initial tilt position, and the switch is opened and closed by a pin 28 that rotates around the rotating shaft 18.

Figure 2 is a block diagram for motor drive, including micro switches 26, 27, motor drive circuits 31, 32, CPU 33, RAM 34, ROM 3.
5 and an operation panel 36.

The operation panel 36 includes a pupil interval selection switch 37 and its indicator 38, an addition power selection switch 41 and its indicator 42, numerical value changeover switches 39 and 40, and a numerical value display section 43.
Consists of etc.

FIG. 3 is a diagram explaining the principle of this embodiment, and shows the distances from the eyeball rotation point 44, the corneal apex 45 (corneal apex position in distance vision), the rotation center 46 of the axis 2, and the near fixation point 47. When a, b, and c are given, and the interpupillary distance in far vision is given as d, the tilting angle θ of the hanging plate 1 is expressed by the following formula.

θ=tan ^-t d/2(a+b+c)...(1) Furthermore, the correction amount e for one side of the interpupillary distance at this point
is expressed by the following formula.

e=(a+b)tanθ...(2) Therefore, by correcting the tilt based on the above formula, an accurate visual acuity test can be performed.

Next, the operation of the embodiment having the above configuration will be explained.

First, the eye to be examined and the measurement lens are aligned. For this purpose, the hanging board 1 is moved up and down,
When the subject rotates the knob 6, the male screw 7 at the bottom of the knob 6 is screwed into the female screw of the shaft 2, so that the shaft 2 can be moved up and down.

By turning on the power switch (not shown)
The CPU 33 issues a signal to rotate the drive motors 9 and 12 in the forward direction, and the motor drive circuits 31 and 32 issue pulse signals. Based on this signal, the drive motor 9
The screws 10 and 11, which are directly connected to the screws 10 and 11, rotate in the direction shown by the arrow in FIG. When the slide table 3 hits the micro switch 26, the micro switch 26 is energized, so that the CPU 33 interrupts generation of the motor rotation signal, and the initial position of the slide table 3 is determined. Similarly,
Since the shaft 13 directly connected to the drive motor 12 rotates in the direction of the arrow in FIG. It can be determined as a position where there is no distance (distance measurement position).

Next, when the examiner changes the distance pupillary distance (hereinafter referred to as PD), use the operation panel 36 in FIG.
Press the PD switch 37 on the top. When the PD switch 37 is pressed, the indicator 38 lights up and the display section 43 shows
Switches to PD display. By pressing the PD movement switch 40 in this state, a signal is issued from the CPU 33 to reversely rotate the drive motor 9 by a predetermined amount.
The motor rotation amount based on the signal is stored in the RAM 34, and a numerical value converted to PD is displayed on the display section 43.

Next, when the examiner presses the addition power switch 41 to perform near measurement, the indicator 42 lights up.
The display section 43 displays a predetermined near work distance, that is, the distance b+c in FIG. 3 (for example, 35 cm). Based on this distance, the ROM 35 determines the rotation speed of the drive motor 12 to rotate the hanging plate 1 by θ.
, the CPU 33 issues a motor reverse rotation signal, and the tilt drive motor 12 rotates by a predetermined amount of rotation through the drive circuit 32. As the tilt drive motor 12 rotates, the wheels 16 and 17 rotate around the shafts 18 and 19 by the worms 14 and 15 directly connected to the rotating shaft 13, and the eccentric shafts 20 and 21 directly connected to the wheels 16 and 17 move. , the hanging plate 1 is tilted by a predetermined amount (equivalent to 35 cm) about the shaft 2 via the bearings 24 and 25.

Furthermore, the unilateral correction amount e of the interpupillary distance based on the tilt amount θ is converted into the rotation amount of the drive motor 9 by the ROM 35, and the motor drive circuit 31
The slide table 3 is driven by a drive motor 9 via the drive motor 9.

After aligning the optical axis and visual axis in this manner, visual acuity measurement is performed.

FIG. 4 is a sectional view of a second embodiment of the vertical mechanism for the hanging plate 1.

Axis 2 and slide stand 3 fixed to hanging plate 1
are in the same positional relationship as in the first embodiment.

The upper part of the shaft 2 is male-threaded, and a nut 51 having a threaded gear formed on its outer periphery is screwed into it. The nut 51 is the thrust bearing 52
It is rotatable on the slide base 3 via the
It meshes with a screw gear 53 that is rotatable around a shaft 54, and a knob (not shown) is arranged on an extension of the shaft 54. When the examiner rotates a knob (not shown) fixed to the shaft 54, the nut 51 rotates via the screw gear 53, and the shaft 2 moves up and down via the screw. The board 1 is raised and lowered.

In the second embodiment, the up and down knobs can be placed in front of the main body.

In the above embodiments, the slide table drive motor and the tilt drive motor are used for both the left and right sides, but the same effect can be obtained even if separate motors are used for each of the left and right measurement lens units.

In addition, although a motor was used in the above embodiment as the tilt drive, a knob could be placed instead of the motor.
A similar effect can also be achieved by the examiner manually rotating the knob by a predetermined amount.

[Effects of the Invention] As explained above, according to the present invention, the complicated cam mechanism found in conventional subjective optometry devices is not required, and a tilting mechanism with a significantly simplified mechanism can be realized. In addition, since the mechanism for vertically moving the measuring lens unit is similarly simple, a self-conscious optometry device can be realized at low manufacturing cost.

[Brief explanation of the drawing]

Fig. 1 shows the hanging part of the measuring lens unit of the subjective optometry device according to the present invention, Fig. 2 is a block diagram for driving the motor, Fig. 3 is a diagram explaining the principle of this embodiment, and Fig. 4 shows the hanging part. FIG. 6 is a cross-sectional view of a second embodiment of the vertical mechanism for lowering the plate 1; 1... Hanging plate, 2... Shaft, 3... Slide stand, 5... Female screw, 7... Male screw 3, 9... Slide stand drive motor, 12... Tilt drive motor, 20, 21 ...Eccentric shaft, 33...CPU.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a subjective optometry device for measuring distance and near refractive power, a tilting means for tilting the right eye measurement lens unit and the left eye measurement lens unit. and a drive motor for changing the distance between the two lens units, and a control means for controlling the drive motor, and the drive motor performs correction of the interpupillary distance that is necessary due to tilting. Self-aware optometry device. (2) Registration of a utility model characterized in that a vertically moving member is arranged on the rotation center axis of the tilting mechanism of the lens unit for right eye measurement or the lens unit for left eye measurement, and the lens unit is moved in the vertical direction. A subjective optometry device according to claim 1.