Phase-contrast haploscope comprising a rotary disc

Abstract: A phase-contrast haploscope includes a disc case 1 and left- and right-hand projectors 48, 49. Left- and right-hand look-through holes 2, 3 are formed in a front plate 1a in its lower half portion. A through window 4 is formed in a rear plate 1b in its lower half portion. Left- and right-hand beam emitting holes 10, 17 and left- and right-hand beam incident holes 10a, 17a corresponding to the left- and right-hand look-through holes 2, 3 are formed in the front plate 1a and the rear plate 1b, respectively, at desired opposed positions. The rotary disc B has through holes 5a-5d and project-through holes 6a-6d and 7a-7d formed therein. The left- and right-hand projectors 48, 49 takes in beams from the left- and right-hand beam incident holes 10a, 17a, irradiates the lantern slides n, o with the beams through appropriate beam transmitting means and projects projecting beams q, r having passed through the lantern slides n, o onto the plane of projection m.

Description: Field of the Invention The present invention relates to a phase-contrast haploscope used to examine various functions of binocular vision, i.e. subjective angle of squint, retinal correspondence, fusion faculty, subjective vision, suppression, aniseikonia, circumflex deviation and others, by separating images of right and left eyes in environment most similar to ordinary vision. Prior Art According to The Medical Dictionary issued by Nanzando Co., Ltd., a haploscope is an optic axis measuring instrument, which forms images of two separate targets which are similar to or identical to each other on both eyegrounds using a prism or reflecting mirror for uniting the images by the capability of binocular vision and examines fusion power, fusional motion, and the relation between adaptation control and convergence from the capability of binocular vision. As shown in Fig. 12, in a conventional synchronous type phase-contrast haploscope which has been practically used, targets g, h of eyes are separated by using a pair of sectors a, b which correspond to right and left eyes and which rotate at a high speed in front of eyes with an inter-hole phase difference of 90 degrees and a pair of right- and left-hand projectors e, f having sectors c, d which are synchronized with the sectors a, b, respectively (an image projected by the right-hand projector e is seen only by the right eye, and an image projected by the left-hand projector f is seen only by the left eye). In the figure, i to l denote rotating motors, m denotes the plane of projection, n and o denote left- and right-hand lantern slides, p denotes an examinee, and q and r denote left- and right-hand projecting beams. Because of a rotating speed (100-120 c/s) higher than a critical fusion frequency, in a subjective sense, both targets g, h are recognized continuously and concurrently. By using such apparatus, it is possible to examine said various functions of binocular vision under conditions quite similar to ordinary vision. On the other hand, there exists a liquid crystal phase-contrast haploscope. The flashing frequency of an image can range from 0.1 to 50 c/s by using liquid crystal shutters which are synchronized with changeover shutters for both eyes. Also, the liquid crystal shutter has an opening/closing characteristic which provides an operation speed up to 50 c/s with a rise/fall time of 5 ms. Another haploscope is disclosed in US-A-4712895. Problems to be Solved by the Invention In said conventional synchronous type phase-contrast haploscope, however, it is necessary to synchronously drive expensive rotating motors i-1 corresponding to a total of four sectors a-d, i.e. a pair of sectors a, b corresponding to right and left eyes and a pair of sectors c, d corresponding to projectors e, f. This is technically difficult to achieve, and a repeated use over a long period of time causes an out-of-step, which is fatal in use. Hence, adjustment for synchronisation is needed on occurence of an out-of-step. This is quite troublesome. On the other hand, in the conventional liquid crystal phase-contrast haploscope, a group of changeover switches must be turned on/off at a high speed for synchronously changing over a total of four shutters, i.e. a pair of changeover shutters corresponding to left and right eyes and left-and right-hand liquid crystal shutters. As a result, a chattering phenomenon occurs, causing the mechanical service life of the group of changeover switches to shorten and the frequency of fault occurrence to increase. Moreover, there is a limit to high-speed changeover, and changeover noise occurs frequently. According to the present invention there is provided a phase-contrast haploscope comprising a disc case which has a front plate having a pair of left-and right-hand look-through holes in its lower half portion and a rear plate having a through window or left-and right-hand through holes formed in its lower half portion, wherein a pair of left-and right-hand beam emitting holes and beam incident holes corresponding to the left and right-hand look through holes are formed respectively in the front plate and in the rear plate at desired opposed positions, and which contains a motor driven rotary disc in a rotatable manner, the rotary disc having through holes and project-through holes formed therein, the through holes and project-through holes sweeping out respective concentric circular paths of different diameters and passing at a high rotational speed between said left-and right-hand look-through holes and said through window or left-and right-hand through holes, opposed to each other, and between said left-and right-hand beam emitting holes and left-and right-hand beam incident holes, opposed to each other, in such a manner as to instantaneously coincide with corresponding holes and the window, and left-and right-hand projectors into which slide loaders allowing a slide to be inserted thereinto and removed therefrom are incorporated and which takes in beams from said beam incident holes, irradiates the slides with the beams through appropriate beam transmitting means and projects projecting beams having passed through onto the plane or projection. Preferred and/or optional features of the invention are set out in claims 2 to 22. In the present invention having the above-described novel means, a single rotary disc is used to change over left-and right-hand targets projected on a plane of projection corresponding to left-and right-hand look-through holes synchronously with the changeover of the left-and right-hand look-through holes. As a result, apparatus according to the present invention is compact, small-scaled, and mobile to any location provided with a power source and does not occupy much space. Moreover, a base can be raised and lowered. In addition, the apparatus is adjustable to meet the physique and face profile of an examinee by adjusting the position of a forehead rest and chin rest. Hence, a common apparatus can be used for examination irrespective of age or sex. Various kinds of examination can be securely performed by regulating the changeover speed of the synchronised left-and right-hand look-through holes and left and right-hand projected targets by changing a motor speed from a control panel on a control box and thus increasing/decreasing the number of revolutions of a rotary disc, by individually adjusting the illuminance of the left-and right-hand projected targets, by zooming left-and right-hand projectors to individually zoom out or in the left-and right-hand projected targets, and by swinging horizontally the left-and right-hand projectors and mirrors and adjusting the vertical angle thereof to individually move the left-and right-hand projected targets. The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a front view showing a phase-contrast haploscope according to a first embodiment of the present invention; Figure 2 is a rear view of the haploscope according to the first embodiment; Figure 3 is a right-hand side view of the haploscope according to the first embodiment; Figure 4 is an enlarged plan view showing a control box of the haploscope according to the first embodiment; Figure 5 is an enlarged front view showing an embodiment of a rotary disc according to the present invention; Fig. 6 is a partially omitted perspective front view showing a disc case with its front plate removed; Fig. 7 is a view showing a case where a halogen lamp is attached to a beam emitting hole formed in the rear plate of the disc case; Fig. 8 is an enlarged front view showing another embodiment of a rotary disc according to the present invention; Fig. 9 is an enlarged front view showing still another embodiment of a rotary disc according to the present invention; Fig. 10 is a front view showing essential portions of a phase-contrast haploscope according to a second embodiment of the present invention; Fig. 11 is a right-hand side view showing essential portions of the haploscope according to the second embodiment; and Fig. 12 is an explanatory illustration showing examination with a synchronous type phase-contrast haploscope according to the prior art. Detailed Description of the Invention Embodiment 1 A first embodiment of the present invention will be described with reference to drawings. Fig. 1 is a front view showing a phase-contrast haploscope according to the present embodiment. Fig. 2 is a rear view showing the haploscope. Fig. 3 is a right-hand side view showing the haploscope. Fig. 4 is a plan view showing a control box. Fig. 5 is an enlarged front view showing a rotary disc of the present embodiment. Fig. 6 is a partially omitted perspective front view showing a disc case with its stationary front plate removed. Fig. 7 is an enlarged plan view of essential portions of the disc case with its top plate removed when a halogen lamp is attached into a left-hand beam emitting hole. Figs. 8 and 9 are enlarged plan views showing other examples of a rotary disc. In the figures, reference symbol A denotes a phase-contrast haploscope according to the present embodiment. B, B' and B'' denote rotary discs used in the present embodiment. Reference numeral 1 denotes a disc case. 1a denotes a front plate, 1b denotes a rear plate, and 1c and 1d denote right- and left-hand side plates. 2 and 3 denote a pair of circular left-and right-hand look-through holes which face left and right eyes, respectively, and which are formed in the front plate 1a at the center of its lower half portion. 4 denotes a through window provided in the rear plate 1b at the lower half portion thereof. 5a-5d denote through holes which have the same diameter as the left- and right-hand look-through holes 2, 3 and which are formed in the rotary disc B on concentric circular path α equally spaced at 90 degrees. 6a-6d denote rectangular arc-shaped inner project-through holes which correspond to the left-hand look-through hole 2 and which are formed in the rotary disc B on concentric circular path τ equally spaced at 90 degrees. 7a-7d denote rectangular arc-shaped outer project-through holes which correspond to the right-hand look-through hole 3 and which are formed in the rotary disc B on concentric circular path β equally spaced at 90 degrees. 8 and 9 denote left-hand connectors which are coaxially mounted to a left-hand beam incident hole 10a and a left-hand beam emitting hole 10 at their outer ends. The holes 10a and 10 are formed in the front plate 1a and rear plate 1b at opposed positions where the holes face on one of inner project-through holes 6a-6d when one of through holes 5a-5d instantaneously coincides with the left look-through hole 2. The beam emitting end of a left-hand optical fiber 11 and the beam incident end of the left-hand transmitting optical fiber 12 are inserted into the left-hand connectors 8, 9 and fixed thereto with set screws 13, 14. 15 and 16 denote right-hand connectors which are coaxially mounted to a right-hand beam incident hole 17a and a right-hand beam emitting hole 17 at their outer ends. The holes 17a and 17 are formed in the front plate 1a and rear plate 1b at opposed positions where the holes face on one of outer project-through holes 7a-7d when one of through holes 5a-5d instantaneously coincides with the right look-through hole 3. The beam emitting end of a right-hand optical fiber 18 and the beam incident end of a right-hand transmitting optical fiber 19 are inserted into the right-hand connectors 15, 16 and fixed thereto with set screws 20, 21. 22 denotes a variable speed motor mounted on the rear plate 1b at its center. The end of a motor shaft 22a extending through the rear plate 1b is fixed to the rotary disc B at its center. 23 denotes a forehead rest attached to a slide rod 23a which is inserted into a guide cylinder 24 mounted on the front plate 1a above the middle between the left- and right-hand look-through holes 2, 3. The slide rod 23a has an unillustrated guide groove extending along its upper edge, and the tip end of an adjusting set screw 25 is engaged with the guide groove for fixing. 26 and 27 denote glass or plastic transparent plates stuck on left- and right-hand cylindrical frames 28, 29 whose stoppers 28a, 29a are mounted to the outer ends of the left- and right-hand look-through holes 2, 3, respectively. 30 denotes a lift support standing upright at the center of a horizontally H-shaped base frame 31 equipped with casters 31a which can be locked. 30a denotes a cylindrical support. 30b denotes a screw rod. 30c denotes a head portion which contains a known adjusting mechanism for raising and lowering the screw rod 30b inserted thereinto by turning a rotary handle 32 in a forward or reverse direction. 32a denotes an adjusting stopper screw for fixing the screw rod 30b at an adjusted position. 33 denotes a table type base. 34 and 35 denote left- and right-hand parallel support stands standing upright on the base 33 to support the disc case 1 thereon. 36 and 37 denote left-and right-hand parallel uprights standing in front of the left-and right-hand parallel support stands 34, 35. 38 denotes a cross-plate which bears a chin rest 38a at its central portion corresponding to the middle between the left- and right-hand look-through holes 2, 3 and which stretches between the left-and right-hand parallel guide uprights 36, 37 in such a manner that its both ends slide up and down along the uprights. 39 denotes a cylindrical slider which is slidably fit onto the right-hand guide upright and which is fixed at an adjusted position with an adjusting set screw 40 in order to position the cross-plate 38 via a sleeve 39a. 41a and 41b denote left- and right-hand light source boxes which are mounted on the bottom face of the base 33 at both sides thereof and to which beam incident ends of the left- and right-hand optical fibers 11, 18 are connected. 42 denotes a control box attached to the right-hand end of the base 33 in a hanging manner with set screws 42a. 43, 44, 45, 46 and 47 denote a main switch, a right-hand bright control, a left-hand bright control, a speed control, and a digital speedometer, respectively, arranged on a control panel 42b. 48 and 49 denote a pair of left- and right-hand projectors which upward penetrate the base 33 with a predetermined spacing. 50 and 51 denote left- and right-hand slide loaders which are incorporated into the left- and right-hand projectors 48, 49, respectively, at their top portions and which allow lantern slides n, o to be loaded thereinto or unloaded therefrom. 52 and 53 denote a pair of left- and right-hand zooms which are mounted on the left- and right-hand projectors 48, 49, respectively, at their top ends. 54 and 55 denote left- and right-hand connectors which are connected to the left- and right-hand projectors 48, 49, respectively, at their bottom ends and into which the beam irradiating ends of the left- and right-hand transmitting optical fibers 12, 19 are inserted and fixed with set screws 56, 57. 58 and 59 denote a pair of left- and right-hand mirrors which are pivoted between left-hand forked brackets 62 and between right-hand forked brackets 63 with pivots 58a, 58b in such a manner that a vertical angle can be adjusted and set as desired and as to face the top ends of the left- and right-hand zooms 52, 53. The left- and right-hand forked brackets 62, 63 stand upright on the left- and right-hand seat rings 60, 61, respectively. The left- and right-hand seat rings 60, 61 are mounted rotatably on the top ends of the left- and right-hand projectors 48, 49 in such a manner as to cover the lower portions of the left- and right-hand zooms 52, 53. 64 and 65 denote a pair of left- and right-hand right-angle handles for swinging the left- and right-hand mirrors 58, 59 horizontally and vertically. The handles 64, 65 are fixed to the inner neighboring sides of the left- and right-hand arms 66, 67 which obliquely downward project from and are located at the middle portions of the back surfaces of the left- and right-hand mirrors 58, 59. 68 denotes a screw rod mounting hardware which is mounted on the bottom face of the base 33 at its center and into which the top end of the screw rod 30b is inserted to be fixed with a stopper screw 69. 70 denotes a plug attached to the end of a power cord 71 extending from the control box 42. As illustrated with a dash-and-two dots line in Fig. 6 and shown in Fig. 7, the left- and right-hand beam emitting holes 10, 17 in the rear plate 1b may be enlarged to obtain left- and right-hand beam emitting holes 10', 17' having a larger diameter, and left- and right-hand halogen lamps 72, 73 may be inserted thereinto for attachment. In this case, electric cords (not shown) in place of the left- and right-hand optical fibers 11, 18 are directly connected to the control box 42, and the left- and right-hand light source boxes 40, 42 become unnecessary. In the phase-contrast haploscope A according to the present embodiment described above, four holes of each kind, i.e. through holes 5a-5d and rectangular arc-shaped project-through holes 6a-6d and 7a-7d are arranged with an inter-hole phase angle of 90 degrees. The number of holes of each kind is not limited to 4. One hole may be provided, or multiple holes may be arranged at the same phase angle. In detail, in the rotary disc B for the phase-contrast haploscope according to the present invention, four holes of each kind, i.e. through holes 5a-5d and project-through holes 6a-6d and 7a-7d are arranged. A rotary disc having a single hole of each kind arranged with an inter-hole angle of 360 degrees, rotary disc B' having two holes of each kind arranged with an inter-hole angle of 180 degrees as shown in Fig. 8, and rotary disc B'' having three holes of each kind arranged with an inter-hole angle of 120 degrees as shown in Fig. 9 may be acceptable. In these cases, when the motor 22 coupled directly with the motor shaft 22a rotates at a speed of 120 c/s or 7200 rpm, the changeover speed is calculated as follows: 1 hole 7200 times/minute 2 holes 7200 x 2 = 14400 times/minute 3 holes 7200 x 3 = 21600 times/minute 4 holes 7200 x 4 = 28800 times/minute Hence, to attain the same changeover speed, 1 hole 7200 rpm 2 holes 7200/2 rpm = 3600 rpm 3 holes 7200/3 rpm = 2400 rpm 4 holes 7200/4 rpm = 1800 rpm Thus, as the number of holes increases, the speed of the motor can be lowered. Accordingly, a torque load can be reduced, and a cheaper motor can be employed. Of course, in place of one large through hole 4 in the present embodiment, a pair of left- and right-hand through holes corresponding to the left- and right-hand look-through holes 2, 3 may be used. The present embodiment has the above-described concrete structure. Operations of the present embodiment will now be described. The apparatus according to the present embodiment is moved to a desired place. The apparatus is locked using the locks 31a' of a group of casters 31a. The plug 70 of the power cord 71 is inserted into a power connector (not shown). After loosening the adjusting stopper screw 32a, the rotary handle 32 is turned in the forward or reverse direction to project or retract the screw rod 30b according to the sitting height of examinee p who sits on a separately prepared chair, so that an appropriate height is attained. The adjusting stopper screw 32a is thereafter tightened. According to the face profile of the examinee p, after loosening the adjusting set screw 25, the forehead rest 23 is advanced or retracted along the guide cylinder 24 until an appropriate position is reached, and the adjusting set screw 25 is then tightened. Also, after loosening the adjusting set screw 40, the cylindrical slider 39 is vertically slid along the left- and right-side parallel guide uprights 36, 37 until the chin rest 38a together with the cross-plate 38 reaches an appropriate position, and the adjusting set screw 40 is then tightened, thus determining the height of the chin rest 38a. Thus, the face of the examinee p with respect to the front plate 1a is set so that both eyes of the examinee p are properly seen from the central portions of the left- and right-hand transparent plates 26, 27 of the left- and right-hand look-through holes 2, 3. After turning on the power switch 43 on the control panel 42b, the left- and right-hand bright controls 44, 45 are adjusted, and the speed controller 46 is adjusted while checking a speed displayed on the digital speedometer 47. Next, the left- and right-hand slide boxes 50a, 51a are pulled out, and the left- and right-hand lantern slides n, o used for an examination are loaded thereinto. The slide boxes are inserted back into the left- and right-hand slide loaders 50, 51. The handles 64, 65 for swinging the left- and right-hand mirrors are operated horizontally and vertically so that for example, the targets h, g on the left- and right-hand lantern slides are projected on the plane of projection m at a desired position. At the same time, operate the left- and right-hand zooms 52, 53 to zoom in or out the projected left-and right-hand targets h, g. After the adjusting operations have been completed, when the rotary disc B is rotated, for example, at a speed higher than the critical fusion frequency (100-120 c/s or higher) as in the conventional phase-contrast haploscope, the left and right changeover speed becomes twice that of the conventional synchronous type phase-contrast haploscope. As the rotary disc B rotates at a high speed in the direction of an arrow as illustrated, the centers of the through holes 5a-5d revolve and sweep out the concentric circular path α. The through holes 5a-5d pass one by one in front of the left- and right-hand look-through holes 2, 3 whose centers are located on the concentric circular path α. One of the through holes 5a-5d coincides instantaneously with the left hand look-through hole 2, and then after the elapse of a predetermined instantaneous time, it coincides instantaneously with the right-hand look-through hole 3. Thus, as a result of the through holes 5a-5d in the rotary disc B revolving counterclockwise and passing in front of the left- and right-hand look-through holes 2, 3, the left- and right-hand look-through holes 2, 3 change over alternately to coincide with one of the through holes. While the rotary disc B makes one rotation, the changeover occurs 4 times for instantaneous coincidence. In parallel with the above, as the rotary disc B rotates, the rectangular arc-shaped inner project-through holes 6a-6d and the rectangular arc-shaped outer project-through holes 7a-7d rotate between the left-hand beam emitting end of the lefthand optical fiber 11 or the left-hand halogen lamp 72 and the beam incident end opposed thereto of the beam incident hole of the left-hand transmitting optical fiber 12 on the front plate 1a or between the right-hand beam emitting end of the right-hand optical fiber 18 or the right-hand halogen lamp 72 and the beam incident end opposed thereto of the beam emitting hole 17a (not shown) of the right-hand transmitting optical fiber 19 on the front plate 1a, and sweep out the inner concentric circular path τ and the outer concentric circular path β, respectively. Synchronously with the instantaneous coincidence of one of the through holes 5a-5d with the left-hand look-through hole 2, one of the rectangular arc-shaped inner project-through holes 6a-6d corresponding to the one of the through holes 5a-5d passes between the beam emitting end of the left-hand optical fiber 11 or the left-hand halogen lamp 72 and the beam incident end opposed thereto of the left-hand transmitting optical fiber 12. At that time, a left-hand projecting beam L emitted from the beam emitting end of the left-hand optical fiber 11 or the left-hand halogen lamp 72 passes through one of the rectangular arc-shaped inner project-through holes 6a-6d and enters the beam incident end opposed thereto of the left-hand transmitting optical fiber 12. The beam irradiates the lantern slide n inserted into the left-hand projector 48 via the left-hand transmitting optical fiber 12. The beam from the left-hand projector passes through the left-hand zoom 52. Then, a projecting beam q reflected on the left-hand mirror 58 projects the left-eye target h on the plane of projection m. Thus, the left eye can visually recognize the left-eye target h through the left-hand look-through hole 2 and one of the through holes 5a-5d coinciding instantaneously therewith and the through window 4. On the other hand, synchronously with the instantaneous coincidence of one of the through holes 5a-5d with the right-hand look-through hole 3, one of the rectangular arc-shaped outer project-through holes 7a-7d corresponding to the one of the through holes 5a-5d passes between the beam emitting end of the right-hand optical fiber 18 or the right-hand halogen lamp 73 and the beam incident end opposed thereto of the right-hand transmitting optical fiber 19. At that time, a right-hand projecting beam L emitted from the beam emitting end of the right-hand optical fiber 18 or the right-hand halogen lamp 73 passes through one of the rectangular arc-shaped outer project-through holes 7a-7d and enters the beam incident end opposed thereto of the right-hand transmitting optical fiber 19 of the right-hand beam incident hole. The beam irradiates the right-hand lantern slide o inserted into the projector 49 via the right-hand transmitting optical fiber 19. The beam from the projector 49 passes through the right-hand zoom 53. Then, a projecting beam r reflected on the right-hand mirror 59 projects the right-eye target g on the plane of projection m. Thus, the right eye can visually recognize the right-eye target g through the right-hand look-through hole 3 and one of the through holes 5a-5d coinciding instantaneously therewith and the through window 4. Thus, the left- and right-hand projecting beams L are intermittently blocked as the rotary disc B rotates. Also, synchronously with the coincidence between the left- or right-hand look-through hole 2, 3 and one of the through holes 5a-5d, the targets h and g of the left and right eyes can be alternately changed over at a high speed and separated completely from each other. An examiner such as a doctor adjusts the orientation of the left- and right-hand mirrors 58, 59 and examines in a third party's manner or objectively various binocular functions including the state of fusing the targets h, g in the vertical and horizontal directions. Embodiment 2 A second embodiment of the present invention will now be described with reference to drawings. Fig. 10 is a front view showing essential portions of a phase-contrast haploscope according to the present embodiment. Fig. 11 is a right-hand side view of the haploscope. The same members as the first embodiment are denoted by the same reference numbers to avoid redundant description. In the figures, A' denotes the phase-contrast haploscope according to the present embodiment. 74 denotes a gantry stand which comprises left- and right-hand supports 74a, 74b standing upright on a base 33 to pass the intermediate portions of left-and right-hand optical fibers 11, 18 therethrough and a top plate 74c. 75 and 76 denote left- and right-hand right-angled triangle shaped auxiliary cases which stand on the top plate 74c of the gantry stand 74 on both sides of a disc case 1 standing on the top plate 74c in such a manner as to support the sides of the disc case and which allow the intermediate portions of the left- and right-hand optical fibers 11, 18 and left- and right-hand transmitting optical fibers 12, 19 to pass therethrough for neat arrangement. 77 denotes a chin rest fixed to a top-end head 80a of a screw rod 80 which passes through the end portion of a stepped crank bracket 78, whose base end is fixed on the bottom face of the top plate 74c of the gantry stand 74 below the middle between left- and right-hand look-through holes 2, 3, and which rises or lowers by turning a cylindrical adjusting nut 79 having knurls 79a and engaging therewith. 81 and 82 denote left- and right-hand pivoting pins which pivot the left- and right-hand projectors 50, 51 in a vertically swinging manner between left-hand forked brackets 87 and between right-hand forked brackets 88, respectively. The left-and right-hand forked brackets 87, 88 stand on forked bracket base coupling portions 85, 86, respectively, in a horizontally rotatable manner, which coupling portions are located on the top ends of left- and right-hand support stands 83, 84 studded upright into a base 33. 89 and 90 denote a pair of handles, as operating means, projecting downward at right angles to auxiliary plates 91, 92 at their rear ends, which auxiliary plates are attached to the bottom portions of slide loaders 50, 51 of left- and right-hand projectors 48, 49. 93 and 94 denote equilibrating tension springs one end of which is attached to the end of the left- or right-hand auxiliary plate 91, 92 with a retaining pin 95 and the other end of which is attached to the forked bracket base coupling portion 85, 86 with a retaining pin 96, thereby giving the behavior of lying down to the left- and right-hand projectors 48, 49 and the left- and right-hand auxiliary plates 91, 92. Other portions are configured in the same manner as the first embodiment. The present embodiment has the above-described concrete structure. Operations of the present embodiment will now be described. While adjusting a forehead rest 23, the vertical position of the chin rest 77 is set according to the face profile of examinee pt by turning the cylindrical adjusting nut 79 in the forward or reverse direction to raise or lower the screw rod 80. Thus, the face of the examinee p is set with respect to the front plate 1a so that both eyes of the examinee p are properly seen from the central portions of the left- and right-hand transparent plates 26, 27 of the left- and right-hand look-through holes 2, 3. The left- and right-hand handles 89, 90 are moved right and left or up and down to horizontally swing the left- and right-hand forked brackets 87, 88 and at the same time to vertically swing the left- and right-hand projectors 48, 49 so that for example, the left- and right-hand targets h, g on the left- and right-hand lantern slides n, o are projected on the plane of projection m at a desired position. At the same time, operate left- and right-hand zooms 52, 53 to zoom in or out the projected left- and right-hand targets h, g. Other members and mechanisms are adjusted in the same manner as the first embodiment, and hence various examinations of the examinee p are executed in the same manner. As described above, a rotary disc according to the present invention provides a higher rotational speed above the critical fusion frequency of a single rotary disc to change over the vision of both right and left eyes and thus to separate targets of both right and left eyes from each other. Hence, it becomes possible to set conditions quite similar to the ordinary vision for both right and left eyes. Thus, under these conditions, it is possible to examine various functions of binocular vision, i.e. subjective angle of squint, retinal correspondence, fusion faculty, subjective vision, suppression, aniseikonia, circumflex deviation and others in near natural state. Accordingly, it is possible to smoothly examine an examinee over a long period of time without causing uncomfortableness or pain and thus to obtain a higher diagnostic reliability. Also, a phase-contrast haploscope according to the present invention allows to adjust it according to the sitting height and face profile of an examinee irrespective of age or sex, and hence can immediately cope with any examinee. A small-sized, light, compact structure allows the apparatus to transfer to any location for use as far as a power source and a required occupational space are available. When not in use, the apparatus can be stored in a compact manner. Moreover, since only one motor is used to rotate a rotary disc, synchronous control is unnecessary, and hence a control technique is quite simple. As a result, the apparatus does not require much adjustment, is hard to go wrong, is very durable, and is easy to maintain. Also, no special skills are required for operation, and an initial cost is lower. The phase-contrast haploscope according to the present invention is equipped with zooms and allows mirrors or projectors themselves to swing horizontally and vertically by handle operations. Thus, left- and right-hand targets projected on the plane of projection can be individually zoomed in or out or moved vertically or horizontally. As a result, it is possible to freely examine various functions of binocular vision, i.e. subjective angle of squint, retinal correspondence, fusion faculty, subjective vision, suppression, aniseikonia, circumflex deviation and others. By changing over the vision of both right and left eyes at a higher rotational speed above the critical fusion frequency of a single rotary disc and accordingly separating targets of both right and left eyes from each other, it becomes possible to set conditions quite similar to the ordinary vision for both right and left eyes. As a result, examinations can be conducted in near natural state. Accordingly, it is possible to smoothly examine an examinee over a long period of time without causing uncomfortableness or pain and thus to obtain a higher diagnostic reliability. Moreover, since as compared with conventional apparatus, the apparatus according to the present invention is smaller in size and scale, is minimized in the number of parts, and uses only one motor, synchronous control is unnecessary, and hence a control technique is quite simple. As a result, the apparatus does not require much adjustment, is hard to go wrong, is very durable, and is easy to maintain. Also, no special skills are required for operation, an initial cost is lower, and the apparatus does not occupy much space.

Claims: A phase-contrast haploscope characterised in that the haploscope comprises a disc case (1) which has a front plate (1 a ) having a pair of left-and right-hand look-through holes (2,3) in its lower half portion and a rear plate (16) having a through window (4) or left-and right-hand through holes formed in its lower half portion, wherein a pair of left-and right-hand beam emitting holes (10,17) and beam incident holes (10 a , 17 a ) corresponding to the left and right-hand look through holes are formed respectively in the front plate and in the rear plate at desired opposed positions, and which contains a motor driven rotary disc (B) in a rotatable manner, the rotary disc having through holes (5 a - 5 d ) and project-through holes (6 a - 6 d , 7 a -7 d ) formed therein, the through holes and project-through holes sweeping out respective concentric circular paths of different diameters and passing at a high rotational speed between said left-and right-hand look-through holes and said through window or left-and right-hand through holes, opposed to each other, and between said left-and right-hand beam emitting holes and left-and right-hand beam incident holes, opposed to each other, in such a manner as to instantaneously coincide with corresponding holes and the window, and left-and right-hand projectors (48,49) into which slide loaders (50,51) allowing a slide to be inserted thereinto and removed therefrom are incorporated and which takes in beams from said beam incident holes, irradiates the slides with the beams through appropriate beam transmitting means and projects projecting beams having passed through onto the plane or projection. A phase-contrast haploscope according to claim 1, wherein the disc case (1) and projectors (48,49) are mounted on a base (33) which can be raised and lowered for positioning. A phase-contrast haploscope according to claim 2, wherein the disc case (1) is mounted on a gantry stand (74) or left-and right-hand parallel support stands (34,35) standing on the base, which left-and right-hand parallel support stands are accompanied by left-and right-hand parallel guide uprights (36,37) standing in front of them. A phase-contrast haploscope according to claim 2 or 3, wherein the base is supported on a mobile lifter support (30,31). A phase-contrast haploscope according to any one of the preceding claims, wherein a forehead rest (23) is fixed to the end of a slide rod (23 a ) which is slidably inserted into a guide cylinder (24) for positioning and adjustment, said guide cylinder being mounted on the front plate (1 a ) above the middle between the left-and right-hand look-through holes (2,3). A phase-contrast haploscope according to any one of the preceding claims, wherein a transparent plate (26,27) is attached to the left-and right-hand look-through holes by appropriate means. A phase-contrast haploscope according to any one of the preceding claims, wherein connectors (9,16) are attached to the left-and right-hand beam emitting holes at their outer ends, and the beam emitting ends of the left-and right-hand optical fibres (11,18) which are respectively connected to light source boxes (41 a , 41 b ) fixed to the lower surface of the base at the lateral sides thereof in a hanging manner, are allowed to be inserted into and fixed to the connectors. A phase-contrast haploscope according to any one of claims 1 to 6, wherein sockets connected with a power cord and allowing halogen lamps (72,73) to be screwed thereinto are fitted inwardly into the left-and right-hand beam emitting holes. A phase-contrast haploscope according to any one of the preceding claims, wherein connectors (8,15) are attached to the left-and right-hand beam incident holes (10 a , 17 a ) at their outer ends, and the beam incident ends of the left-and right-hand transmitting optical fibres (12,19) are allowed to be inserted into and fixed to the connectors. A phase-contrast haploscope according to any one of the preceding claims, wherein a motor (22) is mounted on the outer face of the rear plate (1 b ) and a motor shaft (22 a ) to which the rotary disc is attached penetrates the rear plate inwardly. A phase-contrast haploscope according to any one of claims 2 to 10, wherein a control box (42) is attached to one end of the base in a hanging manner. A phase-contrast haploscope according to any one of the preceding claims, wherein zooms (52, 53) are integrally incorporated into the left-and right-hand projectors at their forward ends. A phase-contrast haploscope according to any one of the preceding claims, wherein connectors are integrally incorporated into the left-and right-hand projectors at their rear ends, and the beam irradiating ends of the left-and right-hand transmitting optical fibres are allowed to be inserted into and fixed to the connectors. A phase-contrast haploscope according to any one of the preceding claims, wherein each of the left-and right-hand projectors (48,49) is pivoted between forked brackets (87,88) in such a manner that a vertical angle is adjustable using operating means of the forked brackets, which forked brackets are mounted on the top ends of left-and right-hand support stands (83,84) standing on the base (33) in such a manner as to be horizontally swingable using the operating means. A phase-contrast haploscope according to claim 14, wherein the operating means includes an equilibrating tension spring (93,94) one end of which is attached to the front end of an auxiliary plate (91,92) attached to the bottom side of a projector and the other end of which is attached to a forked bracket base coupling portion (85,86) thereby always giving the behaviour of lying down, and a handle (89,90) which is attached to the rear end of the auxiliary plate and extends downward at right angles. A phase-contrast haploscope according to any one of claims 1 to 13, wherein the left-and right-hand projectors (48,49) upwardly penetrate the base (33) with a predetermined spacing. A phase-contrast haploscope according to any one of claims 1 to 13 or 16, wherein the left-and right-hand projectors (48,49) include left-and right-hand seat rings (60,61) which are rotatably mounted on the top ends of the projectors in such a manner as to cover left-and right-hand zooms (52,53), forked brackets (62, 63) which stand on the left-and right-hand seat rings in such a manner as to swing horizontally together with the seat rings by operation with operating means for horizontal and vertical swing movement, and left-and right- hand mirrors (58,59) which are pivoted between forked brackets in such a manner that a vertical angle is adjustable using the operating means for horizontal and vertical swing movement and as to face the top ends of the left-and right-hand zooms. A phase-contrast haploscope according to claim 17, wherein the operating means for horizontal and vertical swing movement is a pair of left-and right-hand angle handles (64, 65) which are fixed to the inner sides of the left-and right-hand arms (66,67) which obliquely downwardly project from and are located at the middle portions of the back sides of the left-and right-hand mirrors (58,59). A phase-contrast haploscope according to any one of claims 3 to 14, wherein the gantry stand includes a chin rest (77) which is fixed in a manner capable of being raised or lowered for positioning to the end portion of a crank bracket (78), whose base end is fixed on the bottom face of the top plate (74 c ) of the gantry stand below the middle between the left-and right-hand look-through holes (2,3). A phase-contrast haploscope according to any one of claims 3 to 16, wherein the left-and right-hand parallel guide uprights (36,37) include a cross-plate (38) which bears a chin rest (38 a ) at its central portion corresponding to the middle between the left-and right-hand look-through holes (2,3) and which extends between the left-and right-hand parallel guide uprights in such a manner that its both ends can slide up and down along the parallel guide uprights for positioning. A phase-contrast haploscope according to any one of claims 9 to 16, wherein the intermediate portions of left-and right-hand optical fibres (11,18) and left- and right-hand transmitting optical fibres (12,19) pass through left-and right-hand auxiliary cases (75,76) which stand on the gantry stand (74) on both sides thereof so as to support the sides of the disc case (1), and the intermediate portions of the left- and right-hand optical fibres also pass through the left-and right-hand supports of the gantry stand. A phase-contrast haploscope according to any one of claims 9 to 13, 16, 17, 18 or 20, wherein the intermediate portions of the left-and right-hand optical fibres (11,18) and left-and right-hand transmitting optical fibres (12,19) pass through the left- and right-hand support stands (34,35).

Inventors: ISHIMARU SEIJI, NAKAYAMA SHIGEKATSU, ISHIMARU, SEIJI, NAKAYAMA, SHIGEKATSU
Applicants: TAGAWA DENKI KENKYUSHO COMPANY, TAGAWA DENKI KENKYUSHO COMPANY, INCORPORATED
Application year: 1995
Main classification: A61B3
IPC codes: A61B3