JP2006026257A - Visual acuity tester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visual acuity tester which can easily conduct a visual acuity testing while making the operation brief. <P>SOLUTION: An interlocking mechanism which consists of timing pulleys 25, 32, 53, and 54, timing belts 33 and 55, a transmission shaft 31, and a ratchet mechanism 50 is provided in the apparatus. By this interlocking mechanism, while the operating force of an operation knob 16 is transmitted to rotate a visual target placement lamina 20 and visual targets A-D used for inspection are operated in a way able to arrange to an inspection position, an occluder 65 is rotated and is operated in a way able to arrange to the 1st position of blocking out a left eye visual axis and to the 2nd position of blocking out a right eye visual axis. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a peeping type visual acuity inspection apparatus that examines a visual acuity of a subject by looking into and reading a target such as a Landolt ring.

  Various types of eyesight-type visual acuity inspection devices have been proposed in the past. For example, there is one disclosed in Patent Document 1.

  In the visual acuity test apparatus shown in FIG. 2 of Patent Document 1, a lens unit having a left-eye lens and a right-eye lens and a rotating visual target drum having a plurality of visual targets for performing visual acuity tests are spaced apart from each other by a predetermined distance. It is arranged. The rotary target drum has a substantially quadrangular prism shape and is arranged so that the axial direction of the rotation axis is the left-right direction. In addition, the rotational target drum is arranged on a surface on which the left-eye target and the right-eye target are different from each other, and the left-eye target is located on the front of the left-eye lens on each surface. The visual target is disposed in front of the right-eye lens. Incidentally, the side opposite to the side where the visual target is arranged on each surface is blank. An optical path separation shielding plate for left and right eyes is disposed between the lens unit and the visual target unit at a position separated from the lens unit by a predetermined distance.

  In the visual acuity testing apparatus having such a configuration, the left target eye surface of the rotary target drum is rotated and held so that the left eye target surface faces the lens unit during left eye inspection, and rotated during right eye inspection. The target drum is rotated and held so that the right eye target surface of the target drum faces the lens unit side. Then, the right eye and the left eye are examined by looking into the subject through the lens unit with both eyes and reading each target.

  By the way, in the visual acuity inspection apparatus having the above-described configuration, the eye on the side not to be inspected sees the blank portion of the rotating visual target drum. In other words, the eye on the non-inspected side will see the blank part at the same distance as the target on the inspecting side, so the surface of the blank part is easy to focus on and is distracted by dust on the blank surface. There was a risk that the inspection accuracy could be reduced instead of focusing on the inspection.

  In order to solve such a problem, a blocking member that blocks the left eye line of sight at the first position, blocks the right eye line of sight at the second position, and switches the position according to the eye to be examined. It is considered to provide between the lens unit and the rotation target drum. That is, the more the blocking member is arranged in the vicinity of the lens, the more difficult it is to focus on the surface of the blocking member, and the above-described problem does not occur.

However, only the configuration in which such a blocking member is provided requires two operations: an operation for switching the position of the rotary target drum and an operation for switching the position of the blocking member. Therefore, the operation procedure is complicated and the inspection is troublesome.
Japanese Patent Laid-Open No. 61-234836

  The main object of the present invention is to provide a visual acuity inspection apparatus that can perform visual acuity inspection easily by simplifying the operation.

  Hereinafter, effective means for solving the above-described problems will be described while showing effects.

  Means 1. A target arrangement body that is provided so as to be movable and has a plurality of targets arranged in the moving direction; a peeping unit having a left eye peeping part and a right eye peeping part corresponding to the left and right eyes of the subject; and at least A first position that blocks the left eye line of sight passing through the left eye peeping part and toward the target, and a second position that blocks the right eye line of sight passing through the right eye peeping part and toward the target. An eyesight inspection device for inspecting visual acuity by reading the visual target placed at an inspection position through the peeping portion by operating the operation unit. The operation force is transmitted to move the target arrangement body so that the target used for the inspection can be arranged at the inspection position, and the blocking member can be moved to be arranged at each position. It has an interlocking mechanism that operates.

  That is, by providing an interlocking mechanism, the operation force of the operation unit is transmitted to move the target arrangement body so that the target used for the inspection can be arranged at the inspection position, and the blocking member is moved to the left. It operates so that it can be arranged at a first position where the line of sight is blocked and a second position where the line of sight of the right eye is blocked. Therefore, if the target used for the test is switched and the left eye line of sight is blocked by the blocking member or the right eye line of sight is not blocked, or both eyes are not blocked, that is, either the right eye test, the left eye test or the binocular test. Switching can be performed based on the operation of one operation unit. As a result, the operation is simplified and the visual acuity test can be easily performed.

  Incidentally, the moving direction of the target arrangement body, the blocking member, and the operation unit includes a rotation direction, a sliding direction, and the like. In this case, if the moving direction of the target arrangement body, the blocking member, and the operation unit is the rotation direction, the target arrangement body, the blocking member, the operation unit itself, and the peripheral mechanism can be configured in a compact manner. Therefore, if all of these are moved in the rotation direction, it is possible to further reduce the size.

  Mean 2. In the above means 1, the interlocking mechanism includes a connection release means for releasing the drive connection of the shut-off member so as not to transmit the operation force of the operating portion so as to restrict the movement of the shut-off member exceeding the operating range between the positions. Yes.

  That is, by providing the connection release means, when an operating force exceeding the operating range between the respective positions is generated on the blocking member side, the driving connection of the blocking member is released so that the operation force of the operation unit is not transmitted, Movement of the blocking member exceeding the operating range between positions is restricted. Therefore, if such an operating force is generated for the connection release means, the blocking member stops at each desired position. As a result, the blocking member can be easily disposed at each desired position where the line of sight of one eye is blocked, and the one-eye inspection can be easily performed.

  Means 3. In the above means 2, the interlocking mechanism is such that when the target arrangement body is moved so that the adjacent target is arranged at the inspection position, an operating force is applied to the connection release means so that the blocking member exceeds the operating range. It is configured to.

  That is, when the target to be inspected is switched to the next target, an operating force that causes the blocking member to exceed the operating range acts on the connection release means. The connection release means operates so as to stop the blocking member at each desired position when such an operating force is applied. Therefore, it is desirable to block the one-eye line of sight simply by switching the target to be examined to the next target. A blocking member can be arranged at each position, and a one-eye examination can be performed more easily.

  Means 4. In any one of the above means 1 to 3, operation restriction means for restricting the operation range of the operation unit is provided to restrict movement of the target arrangement object exceeding a predetermined distance between the target targets, and the operation restriction means is provided as the operation part. Can be selected and arranged along the operation direction.

  That is, since the operation range of the operation unit is restricted by the operation restricting means and the movement of the target arrangement object exceeding the predetermined target is restricted, it is possible to limit the combinations of the targets used for the current examination. it can. Therefore, it is possible to prevent erroneous selection of a target unnecessary for the current examination. Moreover, since the operation range of the operation unit can be changed by selecting the operation restricting means along the operation direction of the operation unit, the combination of targets used for the inspection can be changed. If the operation restricting means is detachably provided, the selective arrangement of the operation restricting means can be facilitated.

  Means 5. In any one of the above means 1 to 4, the blocking member passes between the first eye position and the second position and passes through the left eye line of sight and the right eye eye part toward the target. A third position where the right eye line of sight toward the visual target is not blocked by the blocking member is provided.

  That is, when the blocking member is arranged at the third position, the binocular line of sight is not blocked by the shielding member, so that the visual acuity test for both eyes can be performed.

  Means 6. Any one of the above means 1 to 5 includes holding means for holding the position of the target arrangement body every time the target is arranged at the examination position. Note that the holding means is configured such that, for example, when a predetermined operation force is applied, the target arrangement body moves against the holding force.

  That is, since the position of the target arrangement body is held every time the target is placed at the inspection position by the holding means, the target can be easily placed at the inspection position, and unnecessary movement from the inspection position is possible. Can be prevented.

  Mean 7 In any one of the above means 1 to 6, the target location of the target to be used for the examination is set as one location, and the presentation location is set on the center line between the left-eye view portion and the right-eye view portion. The viewing portion and the right eye viewing portion include a prism that refracts the line of sight of the eye to be examined and a lens for creating a virtual image.

  That is, a virtual image of a target with a specified size is created by a lens, and the eye of the test eye is refracted toward the target presented on the center line between the two viewing portions by a prism. It is possible to perform a visual acuity test in which the convergence point (the intersection of the lines of sight of both eyes) is set at a position separated from the target position. Therefore, as the convergence points of both eyes are separated, the burden on the inspection eye can be reduced, so that more accurate inspection can be performed.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS An embodiment of the invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the visual acuity test apparatus 1 according to the present embodiment is arranged with a target side mechanism unit 2 having four targets A to D and a predetermined interval from the target side mechanism unit 2. And a lens unit side mechanism unit 3 having a lens unit 4 as a viewing unit through which the subject looks into, and the subject displays one target A to D presented through the lens unit 4. A visual acuity test is performed by reading.

  The target-side mechanism unit 2 is fixed to the upper part of the column 11 that is erected at the center in the width direction on the rear end side of the base 10 that has a rectangular shape. The target-side mechanism unit 2 includes a base portion (not shown) fixed to the support column 11, and an elliptical front plate 12 is fixed to the front surface of the base portion. A substantially square box-shaped storage case 13 having a storage space for storing the base portion and the like is attached to the front plate 12. As shown in FIG. 3 or FIG. 4, a rotating shaft 15 is rotatably supported on the base portion housed in the housing case 13 along the front-rear direction. In addition, the rotating shaft 15 is located on the center line in the width direction of the base 10 (device 1). The rotary shaft 15 has a rear end portion protruding from the housing case 13 and a front end portion protruding from the front plate 12. As shown in FIG. 1, an operation knob 16 is fixed to the rear end of the rotating shaft 15 protruding from the housing case 13 as an operation unit for the operator to rotate. Incidentally, as will be described later, the holding position of the operation knob 16 is set every 90 °, and a label 17 indicating inspection positions “A” to “D” corresponding to the position is affixed to the surface of the housing case 13. Yes. The inspection positions “A” to “D” are arranged in the order of “A”, “B”, “C”, and “D” in the clockwise direction when viewed from the rear of the apparatus 1.

  As shown in FIGS. 2 to 4, a disc-shaped target arrangement plate 20 as a target arrangement body is fixed to the front end portion of the rotating shaft 15. A circular target film 21 on which the first to fourth targets A to D are printed at intervals of 90 ° is detachably attached to the front surface of the target placement plate 20 with a fixture 22. Incidentally, the first to fourth visual targets A to D are, for example, a set of Landolt rings having a size corresponding to a visual acuity value of 0.1 to 1.5, for example. The directions of the Landolt rings at the same visual acuity value are different (only the first visual target A is shown in FIG. 2). In each of the visual targets A to D, the radial direction of the visual target arrangement plate 20 is set as the vertical direction, and the center side of the visual target arrangement plate 20 is set as the upper side. The target placement plate 20 is rotated through the rotation shaft 15 when the operator rotates the operation knob 16.

  A cover plate 23 that covers the target placement plate 20 is attached to the front plate 12. The cover plate 23 is formed with a presentation window 23a for presenting one target A to D used for the examination. The presentation window 23 a is provided at a position for presenting the visual target arranged at the lower part of the visual target arrangement plate 20. Incidentally, when the operation knob 16 is disposed at the examination position “A”, the first visual target A is presented from the presentation window 23a. The presentation window 23a is located on the center line in the width direction of the base 10 (device 1), that is, on the center line between the left-eye lens 44 and the right-eye lens 45 described later.

  A timing pulley 25 (toothed pulley) is fixed to the rotating shaft 15 in the housing case 13. In addition to the timing pulley 25, a timing pulley 32, 53, and 54, a transmission shaft 31, timing belts 33 and 55, and a ratchet mechanism 50, which will be described later, constitute an interlocking mechanism.

  A disc-shaped holding plate 26 is fixed on the rear side of the timing pulley 25 of the rotating shaft 15. On the outer peripheral surface of the holding plate 26, four holding recesses 26a that are recessed in a semicircular shape are provided at intervals of 90 °. On the other hand, a pair of holders 27 are provided on both sides in the width direction across the holding plate 26. These holder 27 and holding plate 26 constitute holding means. The cage 27 accommodates the coil spring 27b and the ball 27c in a bottomed cylindrical case 27a, and urges the ball 27c against the outer peripheral surface of the holding plate 26 by the coil spring 27b. Note that the opening of the cylindrical case 27a is slightly narrowed so as to prevent the ball 27c to which the urging force acts from jumping out.

  When the holding plate 26 rotates together with the rotary shaft 15 in accordance with the rotation operation of the operation knob 16, the ball 27c of the cage 27 protrudes into the concave portion 26a by the urging force for each holding concave portion 26a provided on the plate 26. Thereby, the rotational direction position of the holding plate 26 is held. When a predetermined operation force is generated by the rotation operation of the operation knob 16, the ball 27c is immersed against the holding force, that is, the urging force of the coil spring 27b, and the holding plate 26 is rotated. Since the holding plate 26 is provided with holding recesses 26a at intervals of 90 °, the holding plate 26, that is, the rotary shaft 15, the operation knob 16, the target placement plate 20, and the timing pulley 25 are provided by the holder 27. It is held at 4 positions at 90 ° intervals. In addition, when it arrange | positions at these four holding positions, each optotype AD is each shown from the presentation window 23a.

  As shown in FIGS. 1 and 2, a rear end portion of a hollow connecting pipe 30 extending in the front-rear direction is fixed to the upper portion of the front plate 12. The connecting pipe 30 is located on the center line in the width direction of the base 10 (device 1). As shown in FIGS. 1, 3, and 4, a round bar-shaped transmission shaft 31 is inserted into the connection pipe 30. The transmission shaft 31 is rotatably supported on both ends of the connection pipe 30 via a pair of metal bearings (not shown) attached to the shaft 31 or the pipe 30. The transmission shaft 31 has a rear end portion protruding from the connection pipe 30 in the housing case 13 of the visual target side mechanism portion 2, and a front end portion protruding from the connection pipe 30 in the case portion 40 of the lens portion side mechanism portion 3.

  A timing pulley 32 is fixed to the rear end portion of the transmission shaft 31 protruding from the connection pipe 30, and an annular timing belt 33 is interposed between the timing pulley 32 and the timing pulley 25 fixed to the rotary shaft 15. (Toothed belt) is hung. The timing pulley 32 is fitted with an O-ring 34 after the timing belt 33 is hooked, and the timing belt 33 is prevented from falling off from the rear end portion of the timing pulley 32. When the timing pulley 25 rotates in accordance with the rotation operation of the operation knob 16, the timing pulley 32 is rotated by the timing belt 33, and the transmission shaft 31 is rotated.

  As shown in FIGS. 1 and 2, the lens unit side mechanism unit 3 is fixed to the front end portion of the connecting pipe 30. The lens unit side mechanism unit 3 includes a case unit 40 that is fixed to the front end of the connection pipe 30. The case portion 40 has a cylindrical shape whose front surface is closed. A forehead abutting portion 41 is formed on the front surface of the closed portion of the case portion 40 so as to project forward when the subject looks into the forehead portion for abutting and stabilizing the forehead portion of the subject. The lens portion 4 is detachably fixed to the lower end portion of the case portion 40 with an attachment screw 42. That is, the lens part 4 with other specifications can be easily replaced.

  The lens unit 4 is a left-eye lens as a left-eye viewing portion having the same shape with respect to a pair of circular mounting holes 43 a provided at positions corresponding to both eyes of the subject in the rectangular base member 43. 44 and a right-eye lens 45 as a right-eye peeping part are attached to each other. The lenses 44 and 45 are set to have the same height from the base 10 as the presentation window 23a that presents the visual targets A to D.

  The left-eye lens 44 and the right-eye lens 45 are configured by bonding a convex lens and a prism. Here, the actual distance between the lens unit 4 (lenses 44 and 45) and the target placement plate 20 (targets A to D) is set to 30 [cm], and the convex lenses in the lenses 44 and 45 are The visual targets A to D that are selected at positions separated by 5 [m], which are normal visual acuity inspection distances without using a known lens, appear to have a predetermined size (virtual images of the targets A to D having a predetermined size) The lens dimensions are set so that is created. In addition, the convergence point of both eyes through the prism is 30 [cm] while the actual convergence point of both eyes (intersection of the eyes of both eyes) is 5 [m], which is the normal visual examination distance. It is set as follows. That is, as the convergence points of both eyes are separated, the burden on the eye to be examined can be reduced, so that a more accurate visual acuity test can be performed.

  Inside the case portion 40, a ratchet mechanism 50 constituting an interlocking mechanism and a connection releasing means is accommodated and fixed. As shown in FIGS. 3 and 4, the ratchet mechanism 50 includes a fixed-side base portion 51 that is fixed to the case portion 40. The fixed-side base portion 51 is configured by bonding two plate materials 51a with a predetermined interval. A rotation shaft 52 is attached to the fixed base portion 51 so as to straddle between the constituting plate members 51a, and the rotation shaft 52 is rotatably supported. The rotation shaft 52 is located on the center line in the width direction of the base 10 (device 1). A movable body 60 is accommodated between the plate members 51 a constituting the fixed side base portion 51. The movable body 60 is accommodated in a state where the rotary shaft 52 is inserted, and is supported so as to be rotatable with respect to the rotary shaft 52.

  A front end portion of the rotating shaft 52 protrudes from the fixed base portion 51, and a timing pulley 53 is fixed to the protruding portion. An annular timing belt 55 is hung between the timing pulley 53 and a timing pulley 54 fixed to the front end portion of the transmission shaft 31. That is, when the timing pulley 54 is rotated together with the transmission shaft 31 as the operation knob 16 is rotated, the timing pulley 53 is rotated by the timing belt 55 and the rotating shaft 52 is rotated. The rotating shaft 52 and the rotating shaft 15 provided in the visual target side mechanism unit 3 rotate in the same direction and do not cause a rotation difference (the rotation ratio between the rotating shafts 15 and 52 is 1). : 1). That is, the drive transmission system between the rotary shafts 15 and 52 is configured such that if the rotary shaft 15 rotates 90 °, the rotary shaft 52 also rotates 90 ° in the same direction.

  Further, as shown in FIGS. 3 and 5, the first and second ratchet plates 56, 57 have a predetermined interval between the plate members 61 a of the movable base portion 61 constituting the movable body 60. And fixed. Note that FIG. 5 used here is a view seen from the back side of the apparatus 1. The first and second ratchet plates 56, 57 are formed in the same shape with a plurality of saw teeth 56 a, 57 a at equal intervals on the outer periphery, and the first ratchet plate 56 and the second ratchet plate 57. Is arranged so that either one of the saw blades 56a and 57a is reversed. That is, the saw blades 56a and 57a are composed of vertical sides 56b and 57b and oblique sides 56c and 57c, and the first ratchet plate 56 is arranged so that the vertical side 56b of the saw blade 56a is on one side in the rotation direction (counterclockwise direction side). The second ratchet plate 57 is disposed such that the vertical side 57b of the saw tooth 57a is on the other side in the rotational direction (clockwise direction side).

  First and second restricting pieces 58 and 59 for restricting the rotation of the movable body 60 are provided on the fixed side base portion 51. As will be described later, the first restricting piece 58 is provided in correspondence with the first ratchet pawl member 62 to restrict the rotation of the movable body 60 in the counterclockwise direction (X1 arrow direction in FIG. 5). 59 is provided corresponding to the second ratchet pawl member 63 in order to restrict the rotation of the movable body 60 in the clockwise direction (X2 arrow direction in FIG. 5).

  The movable body 60 includes a movable base 61, first and second ratchet pawl members 62 and 63, and two coil springs 64. The movable side base portion 61 is configured by bonding two plate members 61 a so as to have a smaller interval than the fixed side base portion 51.

  The movable side base portion 61 accommodates first and second ratchet pawl members 62 and 63 on both sides in the width direction sandwiching the ratchet plates 56 and 57 between the constituting plate members 61a. The first and second ratchet pawl members 62, 63 are substantially L-shaped, have a pair of support shafts 62a, 63a that protrude in the width direction at the base end, and correspond to the first at the tip. The first and second ratchet plates 56 and 57 have substantially the same triangular claw 62b and 63b that are engaged with the vertical sides 56b and 57b of the saw teeth 56a and 57a in the rotation direction. One of the first ratchet pawl member 62 and the second ratchet pawl member 63 is disposed face down so that the directions of the locking claws 62b and 63b face each other. The first and second ratchet pawl members 62 and 63 can swing between the plate members 61a by inserting the support shafts 62a and 63a into the mounting holes 61b of the plate member 61a constituting the movable base 61, respectively. The latching claw 63b of the second ratchet claw member 63 is connected to and separated from the outer peripheral surface of the first ratchet claw member 62 where the latching claw 62b is formed. The ratchet plate 57 can be brought into contact with and separated from the outer peripheral surface where the saw teeth 57a are formed.

  In addition, spring mounting portions 61c are formed at portions of the movable side base portion 61 that are located in the vicinity of the tip portions of the first and second ratchet pawl members 62 and 63, respectively. The spring mounting portion 61c has a coil spring 64 that urges the tip ends of the first and second ratchet pawl members 62 and 63 toward the outer peripheral surfaces (saw teeth 56a and 57a) of the first and second ratchet plates 56 and 57. It is installed.

  Furthermore, the base end part of the eye shield 65 as a shielding member is fixed to the lower end part of the movable side base part 61 (one plate material 61a). The eye shield 65 extends linearly from the base end portion to be fixed, and has a circular blocking portion 65a at the distal end portion. The diameter of the blocking portion 65a is set to be approximately the same as the diameter of the lenses 44 and 45.

  Here, the operation of the ratchet mechanism 50 described above will be described. First, as shown in FIG. 5, the first and second restricting pieces 58 and 59 are not in contact with the first and second ratchet pawl members 62 and 63 ( (Or a slight contact state), the locking claw 62b of the first ratchet claw member 62 is locked in a counterclockwise direction on the saw tooth 56a (vertical side 56b) of the first ratchet plate 56, and the second ratchet The locking claw 63b of the claw member 63 is locked to the sawtooth 57a (vertical side 57b) of the second ratchet plate 57 in the clockwise direction. In this case, the first and second ratchet pawl members 62 and 63 are attached to the movable base 61, and the first and second ratchet plates 56 and 57 are fixed to the rotary shaft 52. 52 is in a drive-coupled state so as to rotate integrally in both rotation directions.

  On the other hand, the movable body 60 and the rotating shaft 52 rotate in the counterclockwise direction (X1 arrow direction in FIG. 5) and the eye shield 65 hangs down (in this case, the center position between both lenses 44 and 45). When the first restricting piece 58 is disposed at a position rotated by 30 ° in the same direction from the first ratchet claw member 62, the first restricting piece 58 is moved away from the first ratchet plate 56 as shown in FIG. The first ratchet pawl member 62 is pushed to release the locked state between the first ratchet pawl member 62 and the first ratchet plate 56. At this time, the other second ratchet pawl member 63 does not engage with the second ratchet plate 57 in the counterclockwise direction, so that it can move even if the rotation of the rotating shaft 52 continues in the counterclockwise direction. The body 60 does not rotate in the same direction any more. That is, this position becomes the rotation end position of the movable body 60 in the counterclockwise direction. Since the other second ratchet pawl member 63 is in a state of locking with the second ratchet plate 57 in the clockwise direction, when the rotation shaft 52 rotates in the clockwise direction, the movable body 60 rotates in the same direction. It is supposed to do.

  Further, when the movable body 60 is rotated together with the rotating shaft 52 in the clockwise direction (X2 arrow direction in FIG. 5) and is disposed at a position rotated 30 ° in the same direction from the reference position where the eye shield 65 hangs down, FIG. As shown in FIG. 3, the second restricting piece 59 pushes the second ratchet claw member 63 in a direction in which the locking claw 63b of the second ratchet claw member 63 is separated from the second ratchet plate 57, and the second ratchet claw member 63 and 2 The latched state with the ratchet plate 57 is released. At this time, the other first ratchet pawl member 62 does not engage with the first ratchet plate 56 in the clockwise direction, so that the movable body 60 can be operated even if the rotation of the rotating shaft 52 continues in the clockwise direction. Will not rotate in the same direction any more. That is, this position is the rotational end position of the movable body 60 in the clockwise direction. Since the other first ratchet pawl member 62 is in a state of being locked with the first ratchet plate 56 in the counterclockwise direction, when the rotary shaft 52 rotates in the counterclockwise direction, the movable body 60 moves in the same direction. It is designed to rotate.

  That is, the movable body 60 is rotated along with the rotation of the rotary shaft 52 within the 60 ° angle range between the rotation end position in the counterclockwise direction and the rotation end position in the clockwise direction. Yes. Accordingly, the eye shield 65 fixed to the movable body 60 can swing within the same angle range, that is, the blocking portion 65a of the eye shield 65 is in front of the left eye lens 44 (left eye line of sight blocking, that is, right eye examination). ) And the front of the right-eye lens 45 (right-eye line-of-sight blockage, that is, left-eye examination).

  Next, the visual acuity inspection method of the visual acuity inspection apparatus 1 configured as described above will be described together with its operation.

  First, in the state of the visual acuity test apparatus 1 shown in FIGS. 1 and 2, the operation knob 16 is arranged at the test position “A”, and the first visual target A is presented in the presentation window 23a. On the other hand, as shown in FIG. 6, the eye shield 65 (blocking portion 65a) is disposed in front of the left-eye lens 44 and blocks the left eye line of sight. That is, it is in a state in which the right eye test can be performed using the first visual target A.

  Next, to perform visual acuity inspection of the left eye, the operation knob 16 is rotated 90 ° clockwise (in the direction of the arrow X2 in FIG. 1) from the inspection position “A” to the inspection position “B” (from the holding position to the next holding position). Rotate). Then, the rotating shaft 15 is rotated in the same direction by the operating force of the operation knob 16, and the target placement plate 20 is rotated 90 ° in the same direction. The second visual target B is presented in the presentation window 23a.

  On the other hand, as shown in FIG. 3 and FIG. 4, the ratchet mechanism 50 is operated via the timing belt 33, the transmission shaft 31, the timing belt 55 and the like in conjunction with the rotation of the target placement plate 20 by the operation force of the operation knob 16. The rotating shaft 52 rotates 90 ° in the clockwise direction. At this time, as shown in FIG. 6, in the ratchet mechanism 50, the second ratchet plate 57 is locked in the clockwise direction with the second ratchet pawl member 63, and the second ratchet plate 57 together with the rotating shaft 52. Is rotated in the clockwise direction, the movable body 60 moves in the same direction via the second ratchet pawl member 63.

  When the movable body 60 is rotated by 60 ° in the same direction, the second ratchet pawl member 63 is pushed by the second restricting piece 59 to move away from the second ratchet plate 57 as shown in FIG. The engagement between the second ratchet pawl member 63 and the second ratchet plate 57 is released. Therefore, the drive connection between the rotating shaft 52 and the movable body 60 is released, and even if the rotating shaft 52 rotates in the same direction, the movable body 60 does not rotate in the same direction any more. By such an operation of the movable body 60, when the eye shield 65 moves in the clockwise direction by 60 ° and the blocking portion 65 a is disposed in front of the right eye lens 45, the movement of the eye shield 65 stops. That is, the left eye vision test using the second visual target B is possible.

  Incidentally, when the operation knob 16 is rotated 90 ° counterclockwise (in the direction of the arrow X1 in FIG. 1) from the inspection position “B” to the inspection position “A” from this state, the target placement plate 20 is 90 in the same direction. The first visual target A is presented again in the presentation window 23a.

  At this time, in the ratchet mechanism 50, the first ratchet plate 56 and the first ratchet pawl member 62 operate in the same manner as the second ratchet plate 57 and the second ratchet pawl member 63 described above (operating as shown in FIGS. 7 to 6). ), The movable body 60 does not rotate further in the same direction from the position rotated 60 ° counterclockwise. Thereby, the eye shield 65 (blocking part 65a) is again arranged in front of the left-eye lens 44. That is, the right eyesight test using the first target A can be performed again.

  Next, in order to switch the targets A to D, for example, from the state shown in FIG. 1, the operation knob 16 is turned 90 ° counterclockwise (in the direction of the arrow X1 in FIG. 1) from the inspection position “A” to the inspection position “D”. Rotate. Then, the optotype placement board 20 is rotated by 90 °, and the fourth optotype D is presented in the presentation window 23a. At this time, as shown in FIG. 6, since the ratchet mechanism 50 restricts the rotation of the movable body 60 in the same direction, the movable body 60 does not move and the position of the eye shield 65 remains unchanged. . That is, the right eye vision test using the fourth visual target D is possible.

  Further, from this state, when the operation knob 16 is rotated 90 ° counterclockwise from the inspection position “D” to the inspection position “C” and the target placement plate 20 is rotated 90 °, the presentation window 23a has the third position. The target C is presented, and the ratchet mechanism 50 restricts the rotation of the movable body 60 in the same direction. Therefore, the movable body 60 does not move and the position of the eye shield 65 is the same as described above. It will remain as it is. That is, the left eyesight test using the third visual target C is possible.

  That is, to summarize the above, when the operation knob 16 is rotated 90 degrees in the direction in which the movable body 60 (eye shield 65) can rotate, the position of the eye shield 65 is switched to the opposite position, and the target placement is also performed. Based on the rotation of the board 20, the targets A to D presented from the presentation window 23a are switched. On the other hand, when the operation knob 16 is rotated by 90 ° in a direction in which the movable body 60 (eye shield 65) cannot rotate any more, the position of the eye shield 65 is maintained as it is and the target placement plate 20 is rotated. Based on, the targets A to d presented from the presentation window 23a are switched. Thereby, it is possible to perform a right eye / left eye examination using each of the first to fourth targets A to D. Incidentally, when the right eye / left eye examination is performed in the operation range of 90 ° of the operation knob 16, the combinations are the first and second targets A and B, the fourth and first targets D and A, and the first. There are four types of 3 and 4 visual targets C and D, and 2 and 3 visual targets B and C.

  Incidentally, by operating the operation knob 16 other than 90 °, it is possible to position the blocking portion 65a of the eye shield 65 between the lenses 44 and 45 as shown in FIG. For example, the operation knob 16 is rotated by about 30 ° in a direction in which the movable body 60 (the eye shield 65) cannot be rotated any more, and then the operation knob 16 is rotated in the reverse direction so that the original inspection positions “A” ˜ Returning to “D”, the blocking portion 65 a of the eye shield 65 is disposed between the lenses 44 and 45. In this case, since both the right eye and the left eye line of sight are not blocked by the eye shield 65 (blocking portion 65a), if any of the targets A to D is used as a target for binocular visual acuity measurement, a binocular examination is performed. Can also be done.

  According to the embodiment described above in detail, the following excellent effects can be obtained.

  In the present embodiment, by providing an interlocking mechanism including the timing pulleys 25, 32, 53, 54, the timing belts 33, 55, the transmission shaft 31, and the ratchet mechanism 50, the operation force of the operation knob 16 is transmitted to the target. First, the placement board 20 is rotated so that the targets A to D used for the examination can be arranged at the examination position presented from the presentation window 23a, and the eye shield 65 is rotated to block the left eye line of sight. The position (the counterclockwise rotation end position in FIG. 6) and the second position (the clockwise rotation end position in FIG. 7) that blocks the right eye line of sight are operated. Therefore, switching of the targets A to D used for the inspection and blocking of the left eye line of sight by the eye shield 65 or blocking of the right eye line of sight or not blocking both eyes, that is, right eye examination or left eye examination or both eyes. Switching between inspections can be performed based on the operation of one operation knob 16. As a result, the operation is simplified and the visual acuity test can be easily performed. In particular, the optotype placement plate 20 and the eye shield 65 are provided apart from each other in the front-rear direction, and the optotype placement plate 20 and the eye shield 65 need to be operated frequently. 16, the significance of linking the target placement plate 20 and the eye shield 65 is great.

  Further, in the present embodiment, since the target placement plate 20, the eye shield 65, and the operation knob 16 are configured to operate in the rotation direction, the target placement plate 20, the eye shield 65, and the operation knob 16 are configured. Etc. and its peripheral mechanism can be configured compactly.

  Further, in the present embodiment, when the ratchet mechanism 50 is provided, if an operating force that exceeds the operating range between the positions shown in FIGS. The driving connection of the eye shield 65 (movable body 60) is released so that the operating force is not transmitted, and the movement of the eye shield 65 exceeding the operating range between the positions is restricted. Accordingly, since such an operating force is generated on the ratchet mechanism 50 when the target is switched, the eye shield 65 stops at each desired position (the positions in FIGS. 6 and 7). As a result, the eye shield 65 can be easily disposed at each desired position where the one-eye line of sight is blocked, and the one-eye examination can be easily performed.

  Further, in the present embodiment, when the targets A to D to be examined are switched to the adjacent targets, the ratchet mechanism 50 is configured so that an operating force that causes the eye shield 65 to exceed the operating range acts. Yes. The ratchet mechanism 50 operates to stop the eye shield 65 at each desired position (the positions in FIGS. 6 and 7) when such an operating force is applied, so that the targets A to D to be inspected are adjacent to each other. By simply switching to the visual target, the eye shield 65 can be arranged at each desired position where the one-eye line of sight is blocked, and the one-eye examination can be performed more easily.

  Moreover, in this Embodiment, since the position of the optotype arrangement | positioning board 20 is hold | maintained whenever it arrange | positions the optotypes AD in the test | inspection position shown from the presentation window 23a with the holding | maintenance plate 26 and the holder | retainer 27, The targets A to D can be easily placed at the inspection position, and unnecessary movement from the inspection position can be prevented.

  In the present embodiment, each lens 44, 45 includes a prism, and the line of sight of the examination eye toward the targets A to D presented from the presentation window 23a on the center line between the lenses 44, 45 by the prism. Is refracted, so that the actual convergence point of both eyes (intersection of the line of sight of both eyes) is separated from the target position, for example, about a distance for performing a visual acuity test without using the lenses 44 and 45 (about 5 [ m] grade). Therefore, as the convergence points of both eyes are separated, the burden on the inspection eye can be reduced, so that more accurate inspection can be performed.

  In the present embodiment, the left eye gaze and the right eye gaze are not blocked by the eye shield 65 between the first position (position in FIG. 6) and the second position (position in FIG. 7). A third position (position in FIG. 5) is provided. Therefore, when the eye shield 65 is arranged at the third position, the binocular line of sight is not blocked by the eye shield 65, so that the visual acuity test of both eyes can be performed.

  In addition, this invention is not limited to the content of description of the said embodiment, For example, you may implement as follows.

  In the above embodiment, the operation knob 16 is configured to be freely rotatable by 360 °. However, for example, as shown in FIG. 8, a guide plate 66 as an operation restricting means for restricting the operation range of the operation knob 16 may be provided. good.

  Specifically, the guide plate 66 is mounted between the operation knob 16 and the housing case 13 so as to be rotatable around the rotation shaft 15 to which the operation knob 16 is fixed, and at an interval of 90 ° around the rotation shaft 15. By screwing a fixing screw 67 into the provided screw hole 13a, the screw hole 13a is fixed so as to be selectively arranged at four rotation positions at intervals of 90 °. At these four fixed positions, two targets (targets A and B, targets D and A, targets C and D, target B) are combined in a restriction window 66a provided on the guide plate 66. , C combination) is displayed. The operation knob 16 has a protrusion (not shown) inserted into the restriction window 66a, and the operation range of the operation knob 16 is restricted between the restriction windows 66a by the protrusion.

  Thereby, it is possible to limit two combinations among the targets A to D used for the current examination (the targets A and B in FIG. 8A and the targets D and A in FIG. 8B). . Therefore, it is possible to prevent erroneous selection of the targets A to D unnecessary for the current examination. Moreover, since the guide plate 66 can be selected and fixed every 90 ° along the rotation direction of the operation knob 16, the combination of the targets A to D used for the inspection can be changed.

  In the above embodiment, the four visual targets, the first to fourth visual targets A to D, are used. However, the number of visual targets is not limited to this and may be changed as appropriate. In this case, the holding interval of the target arrangement plate 20 may be appropriately changed from 90 ° in accordance with the number of targets. Further, when the number is changed, when changing to an adjacent target, the diameter of the timing pulleys 25, 32, 53, and 54 is changed and driven so that the movable body 60 of the ratchet mechanism 50 rotates by 60 ° or more. The transmission ratio may be changed.

  In the above embodiment, the interlocking mechanism is constituted by the timing pulleys 25, 32, 53, 54, the timing belts 33, 55, the transmission shaft 31, and the ratchet mechanism 50. However, the mechanism may be changed as appropriate. For example, instead of the timing pulleys 25, 32, 53, 54 and the timing belts 33, 55, a round belt having a circular cross section and a round belt pulley may be used. Further, the structure of the ratchet mechanism 50 itself may be changed as appropriate.

  In the above embodiment, the target placement plate 20, the eye shield 65, and the operation knob 16 are configured to operate in the rotation direction. However, at least one of these is operated in a direction other than the rotation direction, for example, the slide direction. You may comprise.

  In the above embodiment, the target placement plate 20 is held by the holding plate 26 and the holder 27 every 90 °, but the configurations of the holding plate 26 and the holder 27 may be changed as appropriate.

  In the above embodiment, the operation knob 16 is provided in the target side mechanism unit 2, but may be provided in the lens unit side mechanism unit 3, or may be provided in a place other than both the mechanism units 2 and 3.

  In the above embodiment, the vision test using the lenses 44 and 45 is performed. However, if the lenses 44 and 45 are not necessary for the test, the lenses 44 and 45 may be omitted. In this case, for example, since the lens unit 4 is detachably fixed to the case unit 40 by the mounting screw 42, the base member 43 from which the lenses 44 and 45 are omitted may be mounted.

  In the above embodiment, the target side mechanism unit 2 is fixed to the support column 11, but the target side mechanism unit 2 may be attached to the support column 11 so as to be tiltable or vertically movable.

It is a back perspective view showing a visual acuity inspection device in this embodiment. It is a front perspective view which shows a visual acuity test | inspection apparatus. It is a back perspective view which shows the mechanism part of a visual acuity test | inspection apparatus. It is a front perspective view which shows the mechanism part of a visual acuity test | inspection apparatus. (A) is a rear view of a ratchet mechanism, (b) (c) is the principal part enlarged view. (A) is a rear view of the ratchet mechanism in a state in which the movable body is arranged at the rotation end position in the counterclockwise direction, and (b) is an enlarged view of a main part thereof. (A) is a rear view of the ratchet mechanism in a state in which the movable body is arranged at the rotation end position in the clockwise direction, and (b) is an enlarged view of a main part thereof. (A) and (b) are back perspective views of a visual acuity inspection device in another example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vision test apparatus, 4 ... Lens part, 16 ... Operation knob, 20 ... Visual target arrangement | positioning board, 25, 32, 53, 54 ... Timing pulley, 26 ... Holding plate, 27 ... Cage, 31 ... Transmission shaft, 33 , 55 ... timing belt, 44 ... left eye lens, 45 ... right eye lens, 50 ... ratchet mechanism, 65 ... eye shield, 66 ... guide plate, AD ... first to fourth visual targets.

Claims (5)

A target arrangement body that is movably provided and has a plurality of targets arranged in the moving direction;
A viewing portion having a left eye viewing portion and a right eye viewing portion corresponding to the left and right eyes of the subject;
A first position that cuts at least a left eye line of sight passing through the left eye peeping part toward the target; and a second position of blocking the right eye line of sight passing through the right eye peeping part toward the target. A blocking member provided movably in the
A visual acuity inspection apparatus that inspects visual acuity by reading the optotype placed by the subject at an inspection position through the observation part,
The operation force when operating the operation unit is transmitted to move the target arrangement body so that the target used for the inspection can be placed at the inspection position, and the blocking member is moved to move each of the target members. A visual acuity testing device comprising an interlocking mechanism that operates to be disposed at a position.   The interlock mechanism includes connection release means for releasing the drive connection of the blocking member so as not to transmit the operation force of the operation unit so as to restrict the movement of the blocking member beyond the operating range between the positions. The visual acuity test apparatus according to claim 1, wherein   The interlocking mechanism is configured such that when the target arrangement body is moved so that the next target is arranged at the inspection position, the operating force is such that the blocking member exceeds the operating range with respect to the connection release means. The visual acuity test apparatus according to claim 2, wherein the visual acuity inspection apparatus is configured to act.   In order to restrict movement of the target arrangement body that exceeds a predetermined distance between the targets, an operation restriction unit that restricts an operation range of the operation unit is provided, and the operation restriction unit is selected along an operation direction of the operation unit. The visual acuity inspection apparatus according to claim 1, wherein the visual acuity inspection apparatus can be arranged.   The blocking member passes between the first eye position and the second position, passes through the left eye peeping part, and passes through the left eye line of sight toward the target and the right eye peeping part. 5. The visual acuity test apparatus according to claim 1, wherein the visual acuity inspection apparatus has a third position that does not block both the right-eye line of sight toward the left.

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