JP3150179B2 - Ophthalmic device tilting device and tilting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tilting apparatus and a tilting method for an optometric apparatus used for near-field measurement.

[0002]

2. Description of the Related Art Generally, when an eye is examined by an optometry apparatus, the optical axis of a measuring lens must always be aligned with the visual axis of a person to be measured. On the other hand, if the subject sees a near vision target to measure the near-vision eye refractive power after measuring the far-sighted eye refractive power using the subjective optometric apparatus, The visual axis of the eye changes from a convergence angle state of almost 0 degree to a certain convergence angle (for example, 5 degrees).
Degree). Therefore, when measuring the refractive power of the eye for near vision, the optometric apparatus needs to have a function of rotating the measuring lens so that the optical axis of the measuring lens is aligned with the visual axis of the subject. .

[0003] For this reason, conventionally, the angle of convergence of the eye of the person to be measured when viewing a near vision target placed at a predetermined distance is calculated, and the measurement lens is rotated in accordance with the angle of convergence (tilt). An optometric apparatus in which the optical axis of the measurement lens is further translated so as to coincide with the visual axis of the person to be measured is known, for example, from Japanese Utility Model Laid-Open No. 1-98601.

FIG. 12 is a plan view for explaining a method of tilting a measuring lens in the conventional apparatus. First, the left and right measurement lens units 123a, 12a are added to the pupil distance 122 in the far vision of the eyes 121a, 121b of the subject.
The intervals of the measurement lenses in 3b are matched. And FIG.
As shown in FIG. 2A, the left and right measurement lens units 123 are used in accordance with a previously calculated tilt angle (convergence angle) θ.
A and 123b are raised in the direction of arrow 124 around the measurement lens (only the measurement lens unit 123a is lifted in the figure). Next, as shown in FIG. 12B, the measurement lens units 123a and 123b are moved along the line 126 along the arrow 125 in accordance with the pre-computed eye width correction amount ε.
In the direction (only the measurement lens unit 123a is shown in the figure), so that the optical axis of the measurement lens coincides with the visual axis of the eye to be measured.

The tilt angle (convergence angle) θ and the interpupillary correction amount ε are calculated from the following equations. θ = tan ⁻¹ [d / 2 (a + b + c)] ε = (a + b) tan θ where a is the distance from the eye rotation point to the corneal vertex in far vision, and b is the distance from the corneal vertex to the rotation center of the measurement lens unit. The distance (vertex), c is the distance from the rotation center of the measuring lens unit to the near vision target (near-work target distance), and d is the distance between pupils in far vision.

[0006]

However, in the above-mentioned conventional apparatus, as shown in FIG.
Is calculated, and the measuring lens unit 123 is calculated accordingly.
a and 123b were moved to correct the optical axis of the measurement lens to the visual axis of the eye to be measured. For this correction, it is of course necessary to calculate the interpupillary distance correction amount ε, and furthermore, the measurement lens units 123a, 123b
Is required in the direction of the arrow 125 along the line 126, which causes a problem that the optometry apparatus becomes complicated and costs increase.

Further, the measuring lens units 123a, 1
The interpupillary correction for moving 23b along the line 126 is
Vertex larger than a predetermined value [(a + b)
/ Cos θ-a].
For this reason, there has been a problem that an accurate optometry cannot be performed in near vision measurement.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a tilting apparatus and a tilting method of an optometric apparatus which can perform an accurate optometric test by near measurement, and can reduce the cost with a simple configuration. The purpose is to provide.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a tilting device for an optometry apparatus used for near vision measurement, comprising a left eye unit and a right eye unit opposed to the left and right eyes of a subject. A measuring lens unit section comprising an eye unit and mounted with a measuring lens used for optometry, a PD mechanism section for adjusting a distance between a left eye unit and a right eye unit of the measuring lens unit section, PD
Two moving bases that are moved in the left-right direction by the mechanism unit, two support shafts provided on each of the moving bases, and the respective support shafts are rotatably suspended from the respective support shafts around the respective support shafts, The left-eye unit and the right-eye unit of the measurement lens unit so that the respective rotation axes of the left and right eyes of the subject at a predetermined position with respect to the measurement lens unit coincide with the respective support axes. And a rotation driving means for driving each of the holding members to rotate around the respective support shaft, respectively, is provided.

[0010] In addition, the near-eye measurement provided with a tilting device for rotating the left-eye unit and the right-eye unit of the measurement lens unit of the optometry apparatus around the respective rotation axes of the left and right eyes of the subject. In the tilting method of the used optometry apparatus, the interpupillary distance and the near-work target distance for near vision measurement are read, and the tilt angle is obtained according to the read interpupillary distance and the near-work target distance, and the obtained tilt is determined. A drive signal corresponding to the angle is output to the tilting device,
A tilting method for an optometric apparatus is provided, wherein the tilting apparatus rotates the left-eye unit and the right-eye unit about an angle corresponding to the drive signal around the respective rotation axes. .

[0011]

In the near measurement, the visual axis of the eye of the subject exhibits a certain value of the convergence angle. Therefore, in order to make the optical axis of the measurement lens of the measurement lens unit coincide with the visual axis of the eye of the subject, it is necessary to lift the measurement lens unit at the time of near vision measurement.

As a mechanism for lifting the measurement lens unit, a center axis of the tilt of the left-eye unit and the right-eye unit of the measurement lens unit is provided on both rotation axes of the eye of the subject. . That is, two movable bases which are moved in the left-right direction by the PD mechanism, two support shafts provided on each of the movable bases, and the respective support shafts are rotatably suspended from the respective support shafts. And two holding members. The two holding members move the left-eye unit and the right-eye unit of the measurement lens unit to the left and right eyes of the subject at predetermined positions with respect to the measurement lens unit. Each rotation axis is held so as to coincide with each of the support shafts.

Further, in order to operate such a tilting device of the optometric apparatus, the interpupillary distance and the near-distance target distance for near vision measurement are read, and the tilt angle is obtained according to the read interpupillary distance and the near-distance target distance. A drive signal corresponding to the determined tilt angle is output to the tilt device, and the tilt device rotates the left-eye unit and the right-eye unit around the respective rotation axes as the central axes by an angle corresponding to the drive signal. To

[0014]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is an overall configuration diagram of the optometry apparatus. An optometric apparatus, particularly a subjective optometric apparatus, includes a measuring head unit 1 having a mechanism for measuring visual functions including near and far vision, and a measuring head support for supporting the measuring head unit 1 vertically and horizontally rotatably. It comprises a unit 2, an optometry table 3, and a base unit 4 for supporting these. The measurement head unit 1 includes a measurement lens unit 1a having a measurement lens having a visual function,
Holding the measurement lens unit 1a, the distance between pupils (P
D) for adjusting D).

FIG. 1 is a perspective view schematically showing a vertical movement mechanism for adjusting the position of the measurement lens unit 1a, a convergence mechanism, and a PD mechanism. The measurement lens unit 1a is composed of two units corresponding to the left and right eyes of the subject, and the up-down movement mechanism, the convergence mechanism, and the PD mechanism have symmetrical structures corresponding to the two units, respectively. I have.
In the following, each mechanism for the left eye will be mainly described, and description of each mechanism for the right eye will be omitted.

When measuring the visual function, it is necessary to match the optical axis of the measurement lens with the visual axis of the eye of the subject, and as a device for meeting such a demand, a vertical movement mechanism 11, a convergence mechanism 12, and There is a PD mechanism 13. The PD mechanism 13 is provided in the PD mechanism section 1b, and
It is moved in the direction of arrow 15 relative to the PD mechanism 1b. The moving base 14 is provided with a vertical movement mechanism 11 and a convergence mechanism 12. The vertical movement mechanism 11 moves the measurement lens unit holding bracket 16 having the left eye unit of the measurement lens unit unit 1a fixed thereto in the lower direction relative to the moving base 14 in the direction of the arrow 17; Numeral 12 rotates the measuring lens unit holding bracket 16 in the direction of arrow 18.

First, the vertical movement mechanism 11 includes a vertical movement motor 11a composed of a pulse motor fixed to a moving base 14.
A worm 11b fixed to the drive shaft of the vertically moving motor 11a, a worm wheel body 11c meshed with the worm 11b, and whose movement in the axial direction is restricted by the moving base 14 (details will be described later). A vertical moving shaft 11d, which penetrates the worm wheel body 11c and has a lower end to which a measurement lens unit holding bracket 16 is fixed. The vertical movement shaft 11d is held by the moving base 14 so as to be movable in the axial direction, and at the same time, is held rotatably. The detailed structure of the worm wheel body 11c and the vertical moving shaft 11d will be described with reference to FIG.

FIG. 3 is a partial sectional view of the vertical movement mechanism 11 and the like as viewed from the direction of arrow 19 in FIG. The worm wheel body 11c has a cylindrical shape, a worm wheel is provided on the outside, and a female screw is carved on the inside. The worm wheel body 11c is rotatably held by upper and lower thrust bearings 11e and 11f fixed to the moving base 14. The vertical motion shaft 11d is the worm wheel body 1.
1c and the movable base 14 are penetrated, and an external thread is formed on the outside thereof, and the external thread is meshed with the internal thread of the worm wheel body 11c. The rotation of the vertical motion shaft 11d is regulated by an eccentric shaft 12e described later. Therefore, when the vertical movement motor 11a rotates and the worm 11b rotates, the worm wheel body 11c meshed with the worm 11b rotates. By the rotation of the worm wheel body 11c, the vertical moving shaft 11d meshed on the inner side moves in the vertical direction (the direction of the arrow 17 in FIG. 1) with respect to the moving base. As a result, the measurement lens unit holding bracket 16 moves in the vertical direction, thus controlling the number of pulses supplied to the vertical movement motor 11a, thereby changing the vertical position of the left eye unit of the measurement lens unit 1a. be able to.

FIG. 6 is a partial sectional view of the vertical movement mechanism 11 and the like viewed from the direction of the arrow 20 in FIG. The unit for the left eye of the measurement lens unit 1a is fixed to the lower end of the measurement lens unit holding bracket 16, and the fixed position is such that the eye 21 of the subject is positioned at a predetermined position with respect to the measurement window of the measurement lens unit 1a. The rotation axis (the rotation axis of the eyeball) of the eye 21 of the subject when maintaining the distance (for example, vertex = 12 mm) is set so as to coincide with the axis of the vertical movement axis 11d.

Returning to FIG. 1, the congestion mechanism 12 will be described. The convergence mechanism 12 has a tilt motor 12a composed of a pulse motor fixed to a movable base 14, a worm 12b fixed to a drive shaft of the tilt motor 12a, and a worm wheel meshing with the worm 12b. It comprises a swing shaft 12c, an eccentric plate 12d fixed to the lower end of the swing shaft 12c, and an eccentric shaft 12e fixed to the eccentric plate 12d in parallel with the swing shaft 12c. The tilt shaft 12c is held rotatably with respect to the movable base 14, and at the same time, is held with its movement restricted in the axial direction. The lower end of the eccentric shaft 12e is
Engages with a groove 16a provided in a part of. Groove 16a
The vertical movement axis 11 of the measurement lens unit holding bracket 16
At a part apart from the axis of d, it is provided substantially radially from the axis of the vertical movement shaft 11d.

FIG. 4 is a plan view of such a convergence mechanism 12 as viewed from above in FIG. In the convergence mechanism 12, when the tilt motor 12a rotates, the tilt shaft 12c rotates via a worm wheel engraved on the worm 12b and the tilt shaft 12c. The rotation of the tilt shaft 12c causes the eccentric shaft 12e to rotate about the tilt shaft 12c. Therefore, the measurement lens unit holding fixture 16 engaged with the eccentric shaft 12e in the groove 16a rotates about the vertical movement axis 11d as a center axis, and this is connected to the lower end of the measurement lens unit holding fixture 16 in the measurement lens unit section 1a. The left eye unit will be rotated. That is, by controlling the number of pulses supplied to the tilt motor 12a, the tilt angle of the left-eye unit of the measurement lens unit 1a in the direction of the arrow 18 can be changed. In addition, the rotation axis of the measurement lens unit 1a is the vertical movement axis 11d, and the vertical movement axis 11d coincides with the rotation axis of the eye 21 of the subject as described above.
, The optical axis of the measurement lens of the measurement lens unit 1a does not always deviate from the visual axis of the eye 21 of the person to be measured. This will be described with reference to FIGS.

FIG. 7 is a plan view for explaining a method of tilting the measuring lens in the optometry apparatus according to the present invention. After the distance measurement, the left eye unit 7 of the measurement lens unit
1 is used as the rotation axis 7 of the eye of the subject by the convergence mechanism 12.
When centered on 2, the unit 71 for the left eye rotates from the position shown by the broken line to the position shown by the solid line in the figure. That is,
The optical axis of the measurement lens coincides with the visual axis of the subject's eye only by lifting the left eye unit 71. Therefore, it is not necessary to perform the conventional interpupillary correction, and the apparatus can be simplified. In addition, since the vertex does not become longer and the predetermined value is maintained, an accurate optometry can be performed even in near vision measurement.

FIG. 13 is a bottom view of the main part of the congestion mechanism 12 shown in FIG. 1 as viewed from below. The figure shows the tilt axis 1
2A shows a state in which the measurement lens unit holding bracket 16 is raised due to a difference in the rotational position, (A) shows a state in which the tilt angle is maximum (for example, 10 degrees), and (C) shows a state in which the tilt angle is 0. (B) shows an intermediate state between (A) and (C).

Returning to FIG. 1, the PD mechanism 13 will be described. The PD mechanism 13 includes a PD motor 13a composed of a pulse motor fixed to the PD mechanism 1b, a worm 13b fixed to a drive shaft of the PD motor 13a, and a worm wheel 13c meshing with the worm 13b.
A toothed drive pulley 13d fixed to the shaft of the worm wheel 13c, a toothed driven pulley 13f, a toothed timing belt 13e meshed with the drive pulley 13d and the driven pulley 13f, and one end of the timing belt 13e.
e and a belt connecting plate 13g having the other end fixed to the movable base 14.

FIG. 5 is a plan view of such a PD mechanism 13 as viewed from above in FIG. P in PD mechanism 13
The connection relationship between the D mechanism unit 1b and the movable base 14 will be further described with reference to FIG. 6. A mounting base 22 is provided on the PD mechanism unit 1b, and a slide bearing 23 is fixed to the mounting base 22. The slide bearing 23 is made of a rail-shaped sliding member extending in the traveling direction of the timing belt 13e. A slide support 14 a slidably suspended from the slide bearing 23 and fixed to the movable base 14 is provided. Therefore, the moving base 14 on which the vertical movement mechanism 11, the convergence mechanism 12, and the left eye unit of the measurement lens unit 1a are mounted is slidably held by the PD mechanism 1b via the slide bearing 23 and the like.

In such a holding state, the PD motor 1
When 3a rotates, drive pulley 13d rotates via worm 13b and worm wheel 13c. The timing belt 13e moves by the rotation of the driving pulley 13d, and the movement causes the belt connecting plate 13g fixed to the timing belt 13e and the moving base 14 to move. Therefore, by controlling the number of pulses supplied to the PD motor 13a, the position of the unit for the left eye of the measurement lens unit 1a can be adjusted in the direction of the arrow 15, and the interpupillary distance (PD) of the left eye can be adjusted. Becomes possible.

Next, a method of controlling the driving of each motor of the vertical movement mechanism 11, the convergence mechanism 12, and the PD mechanism 13 will be described. First, the vertical movement (arrow 17 in FIG. 1) by the vertical movement mechanism 11 is caused by the reflection of the optical sensor 24 fixed to the movable base 14 and the reflection of the measurement lens unit holding bracket 16 facing the sensor 24. Plate 25 (FIG. 1,
(See FIG. 6). In addition, the movement (the direction of the arrow 18 in FIG. 1) of the movement by the convergence mechanism 12 is
4 and a reflection disk 27 (see FIGS. 1 and 5) fixed to the upper end portion of the tilt shaft 12c facing the sensor 26. Reflective disk 2
On the side surface of 7, there is provided a partially cut-out reflecting plate. Furthermore, the direction of arrow 15 by the PD mechanism 13 (FIG. 1)
Is moved by the optical sensor 28 fixed to the PD mechanism 1b.
The light is detected by a reflector 29 (see FIG. 5) attached to a portion of the movable base 14 facing the sensor 28. Each of the optical sensors 24, 26, and 28 also has a light emitting unit.

The optical sensors 24, 26 and 28 are used to detect the origin positions which are predetermined reference positions of the vertical movement mechanism 11, the convergence mechanism 12 and the PD mechanism 13, and the optical sensors 24, 26 and 28 are used. Based on the detected origin position,
A pulse signal is supplied from the control device to each of the pulse motors of the vertical movement mechanism 11, the convergence mechanism 12, and the PD mechanism 13, and a desired moving position or rotating position is secured.

FIG. 8 is a block diagram showing the configuration of the control device. The control device 80 includes a PD head substrate 81 and a main control substrate 82, and an input device 83 is connected to the main control substrate 82. An interface circuit 81 is provided for the CPU 81a of the PD head substrate 81.
b, the various optical sensors 24, 26, 2 for the left eye
8 and a signal indicating the origin position from various optical sensors 84 for the right eye. Also, the CPU 8
1a is an interface circuit 81b and a drive circuit 81c.
Through the above-mentioned various motors for the left eye, that is, the vertical motor 11a, the tilt motor 12a, and the PD motor 13
a and various motors 85 for the right eye. Further, the CPU 81a is connected to a ROM 81d storing a control program and a table of a convergence angle described later, a RAM 81e storing various calculation results, and the like, and an RS232C interface 81f for controlling communication with the main control board 82.

Next, the procedure of drive control of various motors executed by the control device 80 will be described. In the following, description will be made including drive control of various motors of the measurement lens unit for the right eye. First, with respect to the up / down motor of the up / down movement mechanism, the pulse signal from the drive circuit 81c corresponds to the up / down direction of the left or right up / down motor input from the input device 83 in accordance with the up / down drive command. And the vertical motion motor rotates by an amount corresponding to the number of the pulse signals. The input device 83 outputs a number of pulse signals corresponding to the number of times the button switch for driving command is pressed in the upward or downward direction, or the number of pulse signals corresponding to the pressing time. By the rotation of the vertical movement motor, the measurement lens unit 1a moves vertically in, for example, 0.5 mm steps, and can move 5 mm in the maximum upward direction and 5 mm in the downward direction. In addition, each of the left and right units of the measurement lens unit 1a can be separately controlled in the vertical direction.

Thus, even if the optical axis of the measuring lens does not coincide with the visual axis of the eye of the person to be measured during the measurement, the left-eye unit or the right-eye unit of the measuring lens unit 1a is individually moved up and down. Since the position can be adjusted, the measuring head 1
The two can be easily matched without moving the whole.

Next, the drive control of the PD motor of the PD mechanism will be described with reference to FIG. FIG. 9 is a flowchart showing a procedure of drive control of the PD motor executed by the control device 80 and an order of operation of the PD mechanism. The figure shows the drive control of the PD motor 13a for the left eye and the operation of the PD mechanism 13, but the drive control of the PD motor for the right eye and the operation of the PD mechanism are the same. In the figure, the numbers following S represent step numbers.

[S1] The interpupillary distance (PD) of the left eye is input from the input device 83. [S2] The CPU 81a converts the input pupil distance of the left eye into a pulse number. [S3] The converted number of pulses are transmitted from the drive circuit 81c to the P
Output to the D motor 13a. [S4] The worm 13 is rotated by the rotation of the PD motor 13a.
b, the worm wheel 13c and the drive pulley 13d rotate. [S5] The timing belt 13e moves by the rotation of the driving pulley 13d. [S6] The belt connecting plate 13g is attached to the timing belt 13e.
The moving base 14 connected via the. Moves in the direction of arrow 15 in FIG. [S7] The measurement lens unit holding bracket 16 connected to the moving base 14 via the vertical movement shaft 11d moves in the direction of arrow 15. [S8] The left eye lens unit of the measurement lens unit 1a suspended by the measurement lens unit holding bracket 16 moves in the direction of arrow 15.

As described above, the left and right units of the measurement lens unit 1a move in the left and right directions (in the direction of arrow 15 in FIG. 1) by an amount corresponding to the interpupillary distance (PD) of one eye input from the input device 83. Moving.

Regarding the PD motor, in addition to the movement according to the interpupillary distance (PD), according to a left or right drive command for the left or right PD motor input from the input device 83, The pulse signal is output from the drive circuit 81c to the corresponding PD motor, and the PD motor rotates by an amount corresponding to the number of the pulse signals. The input device 83 outputs a pulse signal of a number corresponding to the number of times the button switch for driving command in the left direction or the right direction is pressed, or a number of pulses corresponding to the pressing time. Due to the rotation of the PD motor, the left and right units of the measurement lens unit 1a move in the left and right direction in, for example, 0.5 mm steps,
The distance between unilateral pupils (PD) from 25 mm to 40 mm,
Movement is possible. Moreover, each of the left and right units of the measurement lens unit 1a can be separately controlled in the left and right direction.

Further, drive control of the swing motor of the congestion mechanism will be described with reference to FIG. FIG.
9 is a flowchart showing a procedure of drive control of a tilting motor and an operation sequence of a convergence mechanism executed by the control device 80 when performing near vision measurement. The figure shows the drive control of the left-right tilt motor 12a and the operation of the convergence mechanism 12.
The same applies to the drive control of the tilting motor for the right eye and the operation of the convergence mechanism. In the figure, the numbers following S are step numbers.

[S11] The near work target distance c is input from the input device 83. [S12] The distance between pupils (PD) d / 2 of the left eye in far vision is input from the input device 83. [S13] The ROM 81 based on the near work target distance c and the left eye PDd / 2 input in steps S11 and S12.
The convergence angle θ of the left eye is read out with reference to the convergence angle table stored in d. This convergence angle table stores values calculated in advance based on the following equation.

Θ = tan ^-1 [d / 2 (a + b + c)] where a is the distance from the eyeball rotation point to the corneal vertex in far vision (rotation point distance), and b is the rotation center of the measurement lens unit from the corneal vertex. To (vertex), c
Is the distance from the center of rotation of the measurement lens unit to the near target (near-work target distance), and d / 2 is the interpupillary distance (PD) of the left eye in far vision. Usually, a and b are 13
mm and 12 mm, respectively.

FIG. 11 shows an example of a convergence angle table stored in the ROM 81d. [S14] The convergence angle θ read in step S13 is converted into a pulse number. [S15] The converted number of pulses are output from the drive circuit 81c to the tilt motor 12a. [S16] The rotation of the tilt motor 12a causes the worm 12b and the tilt shaft 12c to rotate. [S17] The rotation of the tilt shaft 12c causes the eccentric shaft 12e to rotate. [S18] The rotation of the eccentric shaft 12e causes the measurement lens unit holding bracket 16 to move around the vertical movement shaft 11d with the arrow 18 in FIG.
Rotate in the direction. [S19] The left eye lens unit of the measurement lens unit 1a suspended on the measurement lens unit holding bracket 16 rotates around the rotation axis of the eye of the subject in the direction of arrow 18.

As described above, the convergence angle (tilt angle) θ of one eye is calculated according to the near-work target distance c and the interpupillary distance (PD) d / 2 of one eye, and the tilt motor is moved by an amount corresponding to the angle. To rotate. By controlling the tilting motor in this manner, for example, the convergence angle θ is changed from a maximum of 10.1 degrees (PDd = 80 mm, a near-working target distance c = 200 mm) to a minimum of 2.1 degrees (PDd = 50 mm, a near-working target distance). c =
670 mm).

[0041]

As described above, according to the present invention, the center axes of the tilt of the left-eye unit and the right-eye unit of the measurement lens unit are provided on both the rotation axes of the subject's eye, At the time of near vision measurement, the optical axis of the measurement lens of the measurement lens unit is raised so as to coincide with the visual axis of the eye of the person to be measured. Therefore, it is not necessary to correct the interpupillary distance as in the related art, and therefore, the structure of the optometry apparatus is simplified, and the cost can be reduced.

Further, since the vertex in the near vision measurement does not deviate from a predetermined value, accurate optometry can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a vertical movement mechanism, a convergence mechanism, and a PD mechanism for adjusting a position of a measurement lens unit according to the present invention.

FIG. 2 is an overall configuration diagram of the optometry apparatus.

FIG. 3 is a partial cross-sectional view of a vertical movement mechanism and the like as viewed from the direction of arrow 19 in FIG. 1;

FIG. 4 is a plan view of a convergence mechanism and the like as viewed from above in FIG. 1;

FIG. 5 is a plan view of a PD mechanism and the like as viewed from above in FIG. 1;

FIG. 6 is a partial cross-sectional view of the vertical movement mechanism and the like as viewed from the direction of arrow 20 in FIG. 1;

FIG. 7 is a plan view illustrating a method of tilting a measuring lens in the optometry apparatus according to the present invention.

FIG. 8 is a block diagram illustrating a configuration of a control device.

FIG. 9 is a flowchart illustrating a procedure of drive control of a PD motor executed by the control device and an operation sequence of the PD mechanism.

FIG. 10 is a flowchart showing a procedure of drive control of a tilting motor and an operation sequence of a convergence mechanism executed by a control device when performing near vision measurement.

FIG. 11 is an example of a convergence angle table stored in a ROM.

FIG. 12 is a plan view illustrating a method of tilting a measuring lens in a conventional apparatus.

FIG. 13 is a bottom view of a main part of the congestion mechanism shown in FIG. 1 as viewed from below.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Measuring head part 2 Measuring head support part 3 Eye examination table 4 Base part 11 Vertical movement mechanism 12 Convergence mechanism 13 PD mechanism 14 Moving base 16 Measuring lens unit holding bracket

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61B 3/00-3/16

Claims (6)

(57) [Claims] 1. A tilting device for an optometric apparatus used for near vision measurement, comprising: a left-eye unit and a right-eye unit facing the left and right eyes of a subject, and equipped with a measuring lens used for optometry. A measuring lens unit, a PD mechanism for adjusting an interval between the left-eye unit and the right-eye unit of the measuring lens unit, and two moving substrates moved in the left-right direction by the PD mechanism. Two support shafts provided on each of the movable bases; and a measured object suspended from the respective support shafts so as to be rotatable around the respective support shafts and at a predetermined position with respect to the measurement lens unit. Two holding members for holding a unit for the left eye and a unit for the right eye of the measurement lens unit, such that the respective rotation axes of the left and right eyes of the user coincide with the respective support axes, And a rotation driving means for driving each holding member to rotate around each of the support shafts. 2. The rotation driving means further comprising: a control device for obtaining a tilt angle in accordance with the interpupillary distance and the near-distance target distance for near vision measurement, and outputting a drive signal in accordance with the obtained tilt angle. 2. The apparatus according to claim 1, further comprising a motor for rotational driving, wherein the motor is driven by a drive signal from the control device. 3. The rotation driving means includes: a rotation shaft driven by the motor; an eccentric shaft fixed to the rotation shaft and parallel to the rotation shaft; and a left eye unit or a left eye unit of the measurement lens unit. The tilting device of the optometry apparatus according to claim 2, further comprising an engaging member fixed to the right eye unit and engaged with the eccentric shaft at a point away from a center axis of the support shaft. 4. The apparatus according to claim 1, further comprising up-down moving means for moving the left-eye unit and the right-eye unit in a vertical direction with respect to the PD mechanism by a motor driving force. Or the tilting device of the optometry apparatus according to 3. 5. The apparatus according to claim 4, wherein said vertical movement means is provided on each of said support shafts. 6. A near-field measurement provided with a tilting device that rotates the left-eye unit and the right-eye unit of the measurement lens unit of the optometry apparatus around the respective rotation axes of the left and right eyes of the subject. In the tilting method of the optometry apparatus used, the interpupillary distance and the near-distance target distance in near vision measurement are read, and the tilt angle is determined according to the read interpupillary distance and the near-distance target distance. A drive signal corresponding to an angle is output to the tilt device, and the tilt device rotates the left-eye unit and the right-eye unit about the respective rotation axes as the center axes by an angle corresponding to the drive signal. A tilting method for an optometer.