JP2007068574A - Optometer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optometer capable of inhibiting the influence of backlash by a simple structure. <P>SOLUTION: The optometer for subjectively examining the refraction of an examined eye by switching/disposing various optical elements on an optometric window comprises a pulse motor for disposing the optical elements on the optometric window by the rotation/driving and/or rotating/driving the optical elements disposed on the optometric window around an examination optical axis, a rotation transmitting means, in which the backlash is present, for transmitting the rotation of the pulse motor to the optical elements, a storage means for storing the number of pulses of the pulse motor corresponding to the backlash, and a control means for controlling the rotational position of the optical elements based on the number of pulses of the pulse motor. When the direction of driving of the rotation transmitting means is reversed, the control means does not include the number of pulses stored in the storage means when the driving is started in the number of pulses to be used for controlling the rotational position of the optical elements. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optometry apparatus suitable for visual function inspection of an eye to be examined.

In order to correct a refractive error in the eye to be examined, there is an optometry apparatus that subjectively examines the refractive power of the eye to be examined by switching and arranging optical elements having various optical characteristics to the examination window by a rotating operation. In this type of optometry apparatus, there is an optometry apparatus that can increase the reduction ratio of the motor and gear so that the power of a predetermined optical element can be changed smoothly, and can perform more precise presentation positioning and driving. It is known (see Patent Document 1).
JP 2004-229789 A

When the reduction ratio of the motor and gear is increased as in the optometry apparatus described above, if the rotation is performed only in a predetermined direction (forward rotation), more precise presentation positioning is possible, but the opposite rotation (reverse rotation) Rotation) is easily affected by backlash.
In view of the above problems of the prior art, it is an object of the present invention to provide an optometry apparatus that can suppress the influence of backlash with a simple configuration.

In order to solve the above problems, the present invention is characterized by having the following configuration.
(1) In an optometry apparatus that subjectively examines the refractive power of an eye to be examined by switching and arranging various optical elements in the optometry window, the optical element is arranged in the optometry window by rotation, and / or in the optometry window. A pulse motor that rotationally drives the optical element disposed around the inspection optical axis, a rotation transmission means that transmits the rotation of the pulse motor to the optical element, and has a backlash; and the backlash Storage means for storing the number of pulses of the pulse motor corresponding to, and control means for controlling the rotational position control of the optical element based on the number of pulses of the pulse motor, in the drive direction of the rotation transmission means At the time of reverse rotation, the control means uses the number of pulses for use in the rotational position control of the optical element by the number of pulses stored in the storage means from the start of driving. It is characterized by not including it.
(2) The optometry apparatus according to (1) is characterized by having a changing means for changing the number of pulses stored in the storage means.
(3) In the optometry apparatus according to (1), the rotation transmitting means includes a plurality of rotating disks on which a plurality of the optical elements are arranged, and the number of pulses stored in the storage means is determined for each rotating disk. It is characterized by being set individually.
(4) In the optometry apparatus according to (1), the optical element is a rotary prism, and the control means moves the pulse motor at a speed of 5 pulses / second or more and a speed of 0.1 to 1.0 prism / second. The rotary prism is driven to change the prism power.

  According to the present invention, the influence of backlash can be suppressed with a simple configuration, and precise alignment and driving can be performed in both forward and reverse rotations.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external view showing an overall configuration of an optometry apparatus according to an embodiment.
Reference numeral 1 denotes an optometry table disposed between the subject and the examiner, and 2 denotes a subjective refracting power measuring apparatus. The subjective refracting power measurement apparatus 2 includes a pair of left and right lens units 10 that electrically switch various optical elements to the optometry window 11 and a suspension unit 12 that suspends the left and right lens units 10. The lens unit 10 includes a lens unit 10a for right eye measurement and a lens unit 10b for left eye measurement.
Reference numeral 4 denotes a projection-type target presentation device that presents an inspection target. Reference numeral 5 denotes a controller for operating the subjective refractive power measurement device 2 and the projection target presentation device 4, and 6 is a relay unit that relays communication between the devices.

  FIG. 2 is a view of the controller 5 as seen from above. A liquid crystal display 30 displays optometry information. A switch unit 31 has the following switches. Reference numeral 32 denotes a setting changeover switch group having switches used when setting the various parameters and the like by switching the display screen of the display 30 to the menu screen. 33 is a target switch group for switching the target to be presented to the target presentation device 4, 34 is a mask switch group for applying a mask necessary for the presented target, 35 is a start switch for executing the program optometry, and 37 is changed. A change mode designating switch group for designating a mode such as measurement data, 38 is an input data designating switch group for designating a mode for inputting data or a mode to be measured, Reference numeral 39 denotes a data input switch used when inputting data from an objective eye refractive power measurement device or lens meter, and 41 is a measurement eye designation switch.

  43a and 43b are switches used for a cross cylinder test, a dissolution test using a rotary prism, and a convergence test. During the dissolution test and the congestion test, the rotary prism is rotated in the direction in which the prism frequency is increased by the switch 43a. The rotary prism is rotated in the direction of decreasing the prism power by the switch 43b. The switches 43a and 43b are also used as means for inputting a switch signal for stopping the change in the prism power. A dial switch 42 is used for changing a measured value or shaft angle or inputting a numerical value, and is also used for designating a prism power in a dissolution test and a congestion test. Reference numeral 45 denotes a function switch group, which is used when selecting a switch corresponding to various switch displays displayed at a predetermined position below the screen of the display 30.

  FIG. 3 is a partial cross-sectional view of the left eye measurement lens unit 10b as viewed from above. L is an inspection optical axis, and E is an eye to be examined. In the cover 100 of the lens unit 10b for the left eye measurement, six rotating disks 121 to 126 each having an opening and a plurality of optical elements are arranged around the shaft 130 as a rotation center. The arrangement of each disk is as follows: the strong spherical lens disk 121, the weak spherical lens disk 122, the first auxiliary lens disk 123, the strong cylindrical lens disk 124, the weak cylindrical lens disk 125, and the second auxiliary lens disk 126 in order from the eye E side. It has become. Gears are formed on the outer circumferences of the respective disks, which are rotated by pulse motors 111 to 116, respectively, and optical elements arranged on the optical axis L are switched. A relay gear (not shown) for increasing the reduction ratio is interposed between each disk and the pulse motor, and a rotation transmission mechanism is formed by these.

The strong spherical lens disk 121 holds a spherical lens 131 having an intensity number (−3 to −18D, +3 to + 15D), and the weak spherical lens disk 122 has a weakness number (−0.25 to −1D, +0). .25 to + 1.75D) spherical lens 132 is held. The first auxiliary lens disk 123 holds the auxiliary lens 133. In the holes other than the openings, the shielding plate (BL), the polarizing plates (P135, P45), the Madox lens (MR), and the pinhole (PH). , Green filter / red filter (R / G), dispersive prism (6 / 10Δ), plain lens (PD) with mark for eye width adjustment, + 10D spherical lens, −10D spherical lens, etc. Is provided.
The strong cylindrical lens disk 124 holds a cylindrical lens 134 having an intensity number (−1.5 to −7.5D), and the weak cylindrical lens disk 125 has a weakness number (−0.25 to −1.25D). The cylindrical lens 135 is held. The cylindrical lenses 134 and 135 are provided so as to be rotatable about the optical axis L, respectively.

  On the second auxiliary lens disk 126, auxiliary lenses such as rotary prisms 136a and 136b and a cross cylinder lens 136c are arranged. The rotary prisms 136a and 136b and the cross cylinder lens 136c are provided so as to be rotatable about the inspection optical axis L, respectively. In the rotary prisms 136a and 136b, a pair of prisms having the same power is connected via a gear or the like, and the prism power is changed by rotating the pair of prisms in the opposite direction by the same angle.

FIG. 4 is a diagram illustrating the rotation mechanism of the cylindrical lenses 134 and 135 and the rotary prisms 136a and 136b.
The cylindrical lens 134 is attached to the strong cylindrical disk 124 so as to be rotatable around the optical axis 10 by a holder 140 having a gear. Similarly, the cylindrical lens 135 is attached to the weak cylindrical disk 125 so as to be rotatable about the optical axis L by a holder 141 in which a gear is formed. The gears of the holders 140 and 141 mesh with the sun gear 200 that rotates about the shaft 130, and the rotation of the pulse motor 203 is transmitted to the cylindrical lenses 134 and 135 via the gear 201 and the relay gear 202 connected to the sun gear 200. Transmitted at the same time. Note that a gear head 204 having a reduction ratio of 1/50 is attached to the pulse motor 203, and a gear 205 fixed to an output shaft of the gear head 204 and a relay gear mesh with each other.
With such a configuration, a rotation transmission mechanism that decelerates the rotation of the pulse motor 203 and transmits it to the cylindrical lenses 134 and 135 is configured. Due to the deceleration by the rotation transmission mechanism, the pulse motor 203 is configured to change the axial angle of the cylindrical lens by 1 ° with respect to the drive for 7 pulses.

  The rotary prism 136a is attached to the second auxiliary lens disk 126 so as to be rotatable about the optical axis L by a holder 146 having a gear. The gear of the holder 146 meshes with a sun gear 176 that rotates about the shaft 130, and the rotation of the pulse motor 181 is transmitted to the rotary prism 136 a via a gear 176 a and a relay gear 178 connected to the sun gear 176. A gear head 182 having a reduction ratio of 1/50 is attached to the pulse motor 181, and a gear 183 fixed to the output shaft of the gear head 182 and a relay gear 178 are engaged with each other.

  The rotary prism 136b is attached to a holder 147 that can rotate around the optical axis L on the opposite side of the rotary prism 136a. The gear of the holder 147 is meshed with the sun gear 177. A gear 177 a is connected to the sun gear 177, and the rotation of the pulse motor 184 is transmitted to the gear 177 a via the relay gear 179. A gear head 185 having a reduction ratio of 1/50 is attached to the pulse motor 184, and a gear 186 fixed to the output shaft of the gear head 185 and a relay gear 179 are engaged with each other.

  With such a configuration, a rotation transmission mechanism that decelerates the rotation of the pulse motors 181 and 184 and transmits the rotation to the rotary prisms 136a and 136b is configured. In the deceleration by this rotation transmission mechanism, even when pulse motors 181 and 184 having large step angles (7.5 ° / STEP) are used, the amount of prism change due to the rotation of each pulse motor per step (per pulse) is 0. It is configured to change in steps of 05 prisms or less, more preferably 0.01 prisms or less.

In addition, photosensors (or magnetic sensors) (not shown) are provided in the vicinity of the disks 121 to 126 and the relay gears 178, 179, and 202, respectively, and the reference positions of the disks, the cylindrical lenses 134 and 135, and the rotary prism. The reference positions 136a and 136b are obtained. In the present embodiment, the rotation position at which the center of the opening of each disk is located on the optical axis L, the rotation angle at which the axial angle is 0 ° for the cylindrical lens, and the prism power is 0 for the rotary prism is used as the reference position.
The lens unit 10a for measuring the right eye has the same configuration as the lens unit 10b for measuring the left eye, and the description thereof is omitted.

  FIG. 5 is a block diagram for explaining the control of the apparatus. A switch signal from the switch unit 31 of the controller 5 is input to the microcomputer circuit 50 after being subjected to predetermined processing. The microcomputer circuit 50 is connected to a memory 51 that stores a control program such as an optometry program and a memory 52 that stores objective value data. The microcomputer circuit 50 receives a switch signal. Based on the control program stored in the memory 51, the data is converted into various data, and the screen of the display 30 is controlled via the display circuit 53. Further, the conversion signal is input to the microcomputer circuit 55 of the relay unit 6, and data concerning the refractive power and movement of the lens unit 10 is sent to the subjective refractive power inspection apparatus 2. The microcomputer circuit 55 sends data relating to the visual target to the visual target presenting device 4.

  The microcomputer circuit 60 of the subjective refracting power test apparatus 2 that has received the data regarding refractive power controls the lens unit 10a for measuring the right eye and the lens unit 10b for measuring the left eye, respectively. In the lens unit 10b for left eye measurement, the microcomputer circuit 60 drives the pulse motor 111 via the drive circuit 101, rotates the hyperspherical disk 121, and arranges predetermined optical elements on the inspection window. . Similarly, the microcomputer circuit 60 drives the pulse motors 112 to 116 via the drive circuits 102 to 106, rotates the disks 122 to 126, and places predetermined optical elements on the inspection window.

Reference numeral 61 denotes a memory which is connected to the microcomputer circuit 60. The memory 61 stores in advance the number of pulses of the pulse motor necessary to cope with backlash that occurs when reverse rotation is performed in the rotation transmission mechanism described above. The number of pulses stored in the memory 61 is the number of pulses necessary for the pulse motor to actually start rotation of each of the disks 121 to 126, the cylindrical lens, the rotary prism, etc. with the rotation transmission mechanism having backlash. (In other words, the number of pulses that just offsets the amount of play due to backlash). The number of pulses stored in the memory 61 can be obtained, for example, by performing an examination for correcting backlash during reverse rotation before shipment of the optometry apparatus.
The number of pulses stored in the memory 61 is prepared individually for each optical element that needs to be rotated on each disk and the optical axis L. Note that the controller 5 is used to store the number of pulses in the memory 61. The memory 61 also stores position information of optical elements arranged on each disk with respect to the reference position of each disk.
The microcomputer circuit 60 causes the pulse motors 112 to 116 to pass a predetermined number of pulses via the drive circuits 102 to 106 based on the position information of each optical element stored in the memory 61 and the rotational position information of the current disk. The rotational position of each optical element is controlled by driving only.

  The microcomputer circuit 60 drives the pulse motors 181 and 184 via the drive circuits 107 and 108 when a signal for rotating the optical element, for example, a signal for changing the prism power is input. The rotary prisms 136a and 136b are rotated in opposite directions. The microcomputer circuit 60 similarly controls the right eye measurement lens unit 10a.

  On the other hand, the optotype presenting apparatus 4 that has received the data relating to the optotype projects a predetermined test optotype on a screen (not shown) placed in front of the eye to be examined. Further, the objective eye refractive power measuring device 3 and the lens meter 9 are connected to the microcomputer circuit 55, and the measurement data sent is stored in the memory 56. When a read command signal is input from the microcomputer circuit 50 on the controller 5 side, the microcomputer circuit 55 reads the specified measurement data from the memory 56 and transfers it to the controller 5 side. .

The operation of the apparatus configured as described above will be described.
In this apparatus, since an optometry program in which examination items and examination procedures are set in advance is stored in the memory 51, the optometry program is executed by pressing the start switch 35. Here, the operation of the convergence / divergence inspection after the complete correction power is prescribed for both eyes in the subjective examination using the optometry program of the subjective examination will be described below as an example.

<Spreading inspection>
When the “Kaisan” button 45a provided on the function key 45 is pressed, the rotary prism 136a is placed on both the inspection windows of the subjective refractive power inspection apparatus 2 so that the prism base direction is the BI / BO direction on both eyes. 136b is arranged, and the smallest character that can be correctly read by the examinee or a slightly larger character is presented in a vertical line on the visual target.

  In the divergence inspection, by pressing the switch 43a, a rotation start command signal for rotating the rotary prisms 136a and 136b in the direction of increasing the BI prism power is input, and the pulse motor 181 is controlled by the microcomputer circuit 60. , 184 is started. Note that the rotation transmission mechanism of the subjective refracting power measurement device 2 is placed at a predetermined reference position in advance by an initial operation when the power is turned on, and the microcomputer circuit 60 has a backlash with a rotation direction to be driven next. It is in a state where it can be determined whether or not. Further, the microcomputer circuit 60 performs drive control for rotating the rotation transmission mechanism forward or backward in a direction in which the optical element to be arranged is quickly arranged in the inspection window based on a command signal sent as needed. Therefore, the microcomputer circuit 60 is in a state where it can always be determined whether or not the next moving direction is the rotational direction with backlash.

  FIG. 6 is a diagram schematically showing a fitting state of a part of the rotation transmission mechanism (gear 176a, relay gear 178). Here, when the direction in which the relay gear 178 rotates so as to increase the BI prism power is the A direction shown in FIG. 6 (the state without backlash), the microcomputer circuit 60 performs normal rotation drive control. . Further, by pressing the switch 43a, a command signal for stopping the rotation of the rotary prisms 136a and 136b is input, and the driving of the pulse motors 181 and 184 is stopped.

  Next, when the switch 43b is pressed, a rotation start command signal for rotating the rotary prisms 136a and 136b in a direction to decrease the BI prism power is input. In this case, the relay gear 178 rotates in the reverse direction in the direction B shown in FIG. When the microcomputer 60 has backlash in this way, the microcomputer circuit 60 sequentially counts the number of pulses obtained by driving the pulse motor 181 and based on the number of pulses for backlash correction stored in the memory 61. Thus, only the number of pulses stored since the start of reverse rotation is not included in the number of pulses used for controlling the rotational position of the optical element (not used as a positioning count). After the number of pulses for backlash correction elapses, normal drive control is performed. By pressing the switch 43b again, a command signal for stopping the rotation of the rotary prisms 136a and 136b is input.

The microcomputer circuit 60 rotates the pulse motors 181 and 184 at a speed of 5 pulses / second (pps) or more when rotating the rotary prisms 136a and 136b, and the prism frequency is 0.1 to 1. A drive pulse signal is output so as to change slowly at a speed of 0.0 prism / second. If the pulse motors 181 and 184 are driven at a speed of 5 pulses / second or more, the prism power changes at a speed of 5 times / second or more, so that the change appears as a smooth motion continuously. At this time, the amount of prism change due to rotation of each pulse motor per step is preferably 0.05 prisms or less, and more preferably 0.01 prisms or less. The reason why the prism power is changed at a speed of 0.1 to 1.0 prism / second is that it is easy to check the reaction of the subject in this examination. For example, when the rotation transmission mechanism is configured so that the prism step by the rotation of the pulse motors 181 and 184 is 0.01 prism / pulse, the pulse motors 181 and 184 are driven at a speed of 10 to 100 pulses / second. . This speed is set in advance by the function switch 117. By pressing the switch 117, it is possible to switch in steps of 0.1 prism / second in the range of 0.1 to 1.0 prism / second.
As described above, in the present embodiment, fine drive control is performed by increasing the reduction ratio of the motor and gear, so that fine positioning and smooth optical power change are realized, and the above-described drive control is performed. Thus, it is possible to suppress the influence of backlash that increases by increasing the reduction ratio.

The examiner presses the switch 43a once and rotates the rotary prisms 136a and 136b to continuously and slowly add the BI prism to check whether or not the target is blurred. When the blur is confirmed, the switch 43a is pressed to stop the rotation of the rotary prisms 136a and 136b, and then the “blur” 45c of the function key 45 is pressed to store the value of the prism amount (prism power) at the blur point.
Next, the switch 43a is pressed once, and the BI prism is added slowly and continuously, and it is confirmed whether or not the visual target is visible to the subject. When the target is seen in two, after pressing the switch 43a, the function key 45 "Bully (separation)" 45d is pressed to store the value of the prism amount at the separation point.
This time, the switch 43b is pressed once, and the BI prism is continuously and slowly reduced to check whether or not the target appears to be one (returned) to the subject. When the target is seen as one, after pressing the switch 43b, the function key 45 "Kaifuk (recovery)" 45e is pressed to store the value of the prism amount at the recovery point.

<Congestion inspection>
When the function key 45 "Fuso" 112 is pressed, rotary prisms 136a and 136b are arranged on both eye sides of the subjective refractive power test apparatus 2 so that the prism base direction is the BI / BO direction on both eyes. Is done. On the target, the smallest character that can be read correctly by the examinee or a slightly larger character is presented in a vertical line.

In the congestion check, by pressing the switch 43b, a rotation start command signal for rotating the rotary prisms 136a and 136b in the direction of increasing the BO prism power is input. Further, when the switch 43a is pressed, a rotation start command signal for rotating the rotary prisms 136a and 136b in the direction of decreasing the BO prism power is input. Then, by pressing the switches 43b and 43a again, a rotation stop command signal is input.
As with the divergence test, the values of the prism amounts at the blur point, burr point, and Kaifuk point are stored using various switches.
Even in such a series of inspection flows, the microcomputer circuit 60 performs the above-described drive control to suppress the influence of the backlash when operating the rotation transmission mechanism in the rotation direction in which the backlash exists.

  In the above embodiment, the operation of the convergence / divergence inspection is taken as an example and the rotation of the rotary prism has been described. However, the present invention is not limited to this, and each disk is rotated so that a predetermined optical element is used as the optometry window. It goes without saying that the same drive control is performed for backlash that occurs when the optical elements arranged in the examination window are rotated about the examination optical axis.

  Note that the number of backlash correction pulses stored in the memory 61 can be changed by the controller 5. In order to change, the backlash correction setting screen is called up on the display 30 using the setting changeover switch group 32 of the controller 5. FIG. 7 is a diagram showing an example of the setting screen 300. In the figure, R / L indicates the left and right of the lens unit, and S2 and S1 indicate setting items for the strong spherical lens disk and the weak spherical lens disk. C2 and C1 represent setting items for the strong cylindrical lens disk and the weak cylindrical lens disk. A1 and A2 represent setting items for the first auxiliary lens disk and the second auxiliary lens disk. CA represents a setting item for the axial angle of the cylindrical lens, and P1 and P2 represent setting items for the rotary prism. 301 is a pulse number change column for each item (S2, S1, etc.), and the number of pulses for correcting (cancelling) backlash generated from the pulse motor to the final gear of the rotation transmission mechanism in each item is input. The The display 30 is a touch panel, which is selected by touching the pulse number change field 301 to be changed, and is changed using the dial switch 42 of the controller 5. The setting is confirmed by touching the setting button 302. The confirmed content is stored in the memory 61.

It is the schematic which showed the external appearance of the optometry apparatus in this embodiment. It is the figure which showed the structure of the controller. It is the figure which showed the structure of the lens unit. It is a figure explaining the rotation mechanism of the optical element provided in the disk. It is the block diagram which showed the control system of the optometry apparatus in this embodiment. It is the figure which showed roughly the one part fitting state of the rotation transmission mechanism in this embodiment. It is the figure which showed the structure of the screen for correct | amending backlash.

Explanation of symbols

2 subjective refracting power measurement device 5 controller 10 lens unit 60 microcomputer circuit 61 memory 121 strong spherical lens disk 122 weak spherical lens disk 123 first auxiliary lens disk 124 strong cylindrical lens disk 125 weak cylindrical lens disk 126 second auxiliary lens disk 181 Pulse motor 184 Pulse motor

Claims (4)

In an optometry apparatus that switches and arranges various optical elements in an optometry window and subjectively examines the refractive power of the eye to be examined, the optical elements are arranged in the optometry window by rotation driving, and / or arranged in the optometry window A pulse motor for rotationally driving the optical element about the inspection optical axis, a rotation transmitting means for transmitting the rotation of the pulse motor to the optical element and having a backlash, and corresponding to the backlash Storage means for storing the number of pulses of the pulse motor, and control means for controlling the rotational position control of the optical element based on the number of pulses of the pulse motor, at the time of reverse rotation of the drive direction of the rotation transmission means The control means includes only the number of pulses stored in the storage means from the start of driving in the number of pulses used for the rotational position control of the optical element. Optometric apparatus characterized that no. The optometry apparatus according to claim 1, further comprising changing means for changing the number of pulses stored in the storage means. 2. The optometry apparatus according to claim 1, wherein the rotation transmitting means has a plurality of rotating disks on which a plurality of the optical elements are arranged, and the number of pulses stored in the storage means is individually set for each rotating disk. An optometry apparatus characterized by the above. 2. The optometry apparatus according to claim 1, wherein the optical element is a rotary prism, and the control means moves the pulse motor at a speed of 5 pulses / second or more and a speed of 0.1 to 1.0 prism / second. An optometry apparatus that is driven so as to change the prism power.

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