JP4764664B2 - Ophthalmic examination equipment - Google Patents

Description

  The present invention relates to an ophthalmic examination apparatus, and in particular, an ophthalmic examination that is applied to, for example, a perimeter, and that presents an examination target on the subject's eye and inspects the subject's eye based on the visual recognition status of the subject Relates to the device.

  As this type of ophthalmic examination apparatus, in particular, a perimeter, there is a conventional one disclosed in Patent Document 1, for example. According to this prior art, a light beam for forming a visual target is irradiated onto a micromirror device composed of an assembly of micromirrors. The light beam applied to the micromirror device is reflected toward the eye to be examined. At this time, the individual micromirrors are polarized and driven, so that the reflected light flux is regulated, and the examination target is presented to the eye to be examined. When the subject is able to visually recognize the target, the subject is notified of the fact that the target has been visually recognized, for example, by operating a response button.

JP 2005-102946 A

  By the way, such a perimeter is used, for example, for examination of glaucoma. In the examination of glaucoma, the above-mentioned visual target may be flashed and presented. This is because the visual sense of the subject (human) has frequency dependency. In this case, the subject operates the response button when he / she can visually recognize that the target is blinking.

  However, in the above-described prior art, the visual target is presented with higher brightness (luminance) than the surroundings, that is, the background. Therefore, when the target is presented to the eye to be examined, the amount of light incident on the eye to be examined increases at that moment. Then, the increase in the amount of incident light stimulates the subject's eye (retina), and as a result, the subject may mistakenly recognize that the increase in the amount of incident light is blinking the target. That is, the response button may be operated before the target blinks, and there is a problem that a highly reliable test result cannot be obtained.

  Therefore, an object of the present invention is to provide an ophthalmic examination apparatus that can perform an ophthalmic examination more accurate than before.

  In order to achieve such an object, the present invention provides an eye chart in an ophthalmic examination apparatus that presents a test target to an eye to be examined and inspects the eye to be examined based on a visual recognition state of the target by the eye to be examined. It is characterized by being alternately presented in a first mode having the same brightness as the background and a second mode having a lower brightness than the background.

  That is, in the present invention, the visual target is alternately presented in two modes, that is, a first mode having the same brightness as the background and a second mode darker than the background, in other words, flashing. That is, the target is presented at least at a brightness below the background. Therefore, even if a visual target is presented to the eye to be examined, the amount of light incident on the eye to be examined does not increase and stimulation is suppressed.

  In the present invention, for example, one light source means, an optical path forming means for forming two optical paths between the light source means and the eye to be examined, and one of these two optical paths are provided to travel along the one optical path. Provided are background presentation means for presenting a background with a first light beam from the light source means, and target presentation means for presenting a target with a second light beam from the light source means that is provided in the other optical path and travels along the other optical path. It is embodied by.

  According to this configuration, the background is presented by the first light beam, and separately, the visual target is presented by the second light beam. However, the first light beam and the second light beam are emitted from the same light source means. That is, the light source means for presenting the background and the light source means for presenting the visual target are shared. Therefore, the brightness of the background and the highest brightness of the target, that is, the brightness in the first mode are necessarily the same.

  In this case, the background presentation means has a first incident surface on which the first light beam is incident, and the first projection that projects the first light beam incident on the first incident surface onto the eye to be examined according to the first control signal. And the first light beam incident on the portion corresponding to the background of the first incident surface of the first projection unit is projected to the eye to be examined and the first light beam incident on the portion corresponding to the target is not And a first control unit that generates a first control signal so as to be projected. Further, the optotype presenting means has a second incident surface on which the second light ray is incident and has a second incident surface that projects the second light ray incident on the second incident surface onto the eye to be examined according to the second control signal; The second light beam incident on the portion corresponding to the target of the second incident surface of the second projection means is projected onto the eye to be examined, and the second light beam incident on the portion corresponding to the background is unprojected. The second control means for generating the second control signal and the invalidation means for intermittently invalidating the projection of the second light beam on the eye to be examined by the second projection means may be provided. Good.

  According to this configuration, the first incident surface of the first projection means has a portion corresponding to the background and a portion corresponding to the visual target. And a 1st light ray injects into this 1st entrance plane. Here, the first light beam incident on the portion corresponding to the background of the first incident surface is projected to the eye to be examined as background light. On the other hand, the first light beam incident on the portion corresponding to the target on the first incident surface is not projected onto the eye to be examined. The operation of the first projection means for projecting background light onto the eye to be examined in this way is controlled by the first control means (first control signal). The second incident surface of the second projection means also has a portion corresponding to the background and a portion corresponding to the visual target. The second light beam is incident on the second incident surface. Here, the second light beam incident on the portion of the second incident surface corresponding to the visual target is projected onto the eye to be examined as so-called visual target light. On the other hand, the second light ray incident on the portion corresponding to the background of the second incident surface is not projected onto the eye to be examined. The operation of the second projection means for projecting the target light on the eye to be examined in this way is controlled by the second control means (second control signal). Furthermore, the projection of the target light onto the eye to be examined by the second projecting unit is invalidated intermittently by the invalidating unit. In this way, the projection of the target light to the eye to be examined is intermittently invalidated, thereby realizing the blinking display of the target.

  Here, the invalidating means may include blocking means for intermittently blocking the target light.

  In addition, the present invention provides two light source means having the same specification and a background that is provided in a first optical path from one of the two light source means to the eye to be examined and that presents a background by a first light beam emitted from the one light source means. The present invention is also realized by providing a presentation unit and a target presentation unit that is provided in a second optical path from the other light source unit to the eye to be examined and presents a target with a second light beam emitted from the other light source unit. The

  According to this configuration, the background is presented by the first light beam emitted from one light source means, and the visual target is presented by the second light beam emitted from the other light source means. However, the light source means have the same specifications. In other words, the first light beam and the second light beam are substantially equivalent light beams. Therefore, the brightness of the background and the brightness of the target in the first aspect are necessarily the same.

  In this case, as described above, the background presenting means has a first incident surface on which the first light beam is incident, and the first light beam incident on the first incident surface is applied to the eye to be examined according to the first control signal. The first projection means for projecting and the first light beam incident on the portion corresponding to the background of the first incident surface of the first projection means is projected onto the eye to be examined and is incident on the portion corresponding to the target. The first control unit that generates the first control signal so that one light beam is not projected may be provided. Further, the optotype presenting means has a second incident surface on which the second light ray is incident and has a second incident surface that projects the second light ray incident on the second incident surface onto the eye to be examined according to the second control signal; The second light beam incident on the portion corresponding to the target of the second incident surface of the second projection means is projected onto the eye to be examined, and the second light beam incident on the portion corresponding to the background is unprojected. The second control means for generating the second control signal and the invalidation means for intermittently invalidating the projection of the second light beam on the eye to be examined by the second projection means may be provided. Good.

Note that the invalidating means in this case may include a stopping means that intermittently stops the generation of the second light beam by the other light source means (that is, blinks the other light source means).

  Further, in the present invention, a cycle changing means for arbitrarily changing the cycle for switching between the first mode and the second mode, that is, the blinking cycle, may be provided.

  Moreover, you may further provide the shape change means which changes the shape of a target arbitrarily.

  Then, color changing means for arbitrarily changing the colors of the background and the target may be provided.

  Furthermore, you may provide the brightness change means which changes arbitrarily the brightness of the target in a background and a 1st aspect.

  Such an invention is particularly suitable for a perimeter for measuring the visual field of an eye to be examined.

According to the present invention, the visual target is presented with brightness at least below the background. Therefore, compared to the above-described conventional technique in which the visual target is presented with higher brightness than the background, the stimulation to the eye to be examined due to the presentation of the visual target is suppressed. Accordingly, it is possible to reduce erroneous recognition by the subject that the target is presented as blinking of the target, and thus it is possible to obtain a test result with higher reliability than before. This is extremely effective in a so-called subjective examination in which the examination proceeds based on the subjectivity of the subject, such as a visual field examination.

  A first embodiment of a perimeter to which the present invention is applied will be described with reference to FIGS.

  The perimeter 10 according to the first embodiment is a so-called static perimeter, and includes one light source 12 as shown in FIG. The light source 12 includes, for example, a light emitting diode (LED) or a halogen lamp, and outputs substantially white light. The brightness (luminance) of the light source 12 can be arbitrarily adjusted by the luminance controller 14.

  The light output from the light source 12 is corrected to parallel light by the collimator lens 16 and then incident on a polarizing prism (beam splitter) 18 as a separating unit. The polarizing prism 18 has optical characteristics (reflectance characteristics and transmittance characteristics) as shown in FIG. 2 in the visible light region. The incident light is converted into P (Parallel) polarized light and S (Senkrecht) polarized light. To separate. Of these, the P-polarized light (solid arrow) travels in the same direction as the direction of incidence of light on the polarizing prism 18 and is incident on the liquid crystal (LED) shutter 20 as the first projection means (FIG. 1). At the left side).

  The liquid crystal shutter 20 forms a shutter pattern as shown in FIG. 3, for example, according to the first control signal given from the liquid crystal controller 22. Specifically, in the square effective area 50, only a circular portion 52 that is sufficiently smaller than the effective area 50 is set as a shielding region, and the other portion 54 is set as a transmission region. Accordingly, among the P-polarized light incident on the incident surface of the liquid crystal shutter 20, the light incident on the transmission region 54 is transmitted through the liquid crystal shutter 20 and straight from the emission surface (right surface in FIG. 1). Is emitted. On the other hand, the P-polarized light incident on the shielding region 52 is not emitted. Note that the position of the shielding region 52 can be arbitrarily changed within the effective area 50.

  The P-polarized light that has passed through the liquid crystal shutter 20 (emitted from the exit surface of the liquid crystal shutter 20) is incident on a polarizing prism 24 that is provided separately from the polarizing prism 18 described above. The polarizing prism 24 has optical characteristics as shown in FIG. Accordingly, the P-polarized light incident on the polarizing prism 24 passes through the polarizing prism 24 as it is and proceeds straight. The P-polarized light that has passed through the polarizing prism 24 passes through the magnifying optical system 26 and is projected onto the eye of the subject not shown. Although not shown in detail in the figure, the magnifying optical system 26 includes a lens for focus adjustment. The lens moves along the optical axis direction, so that the eye to be examined (retina) and the liquid crystal shutter 20 are moved. Focus adjustment is performed so that the exit surface is conjugated, that is, the focus of the subject eye is aligned with the exit surface of the liquid crystal shutter 20.

  The S-polarized light (dotted arrow) separated by the polarizing prism 18 proceeds in a direction perpendicular to the incident direction of the light to the polarizing prism 18 with respect to the P-polarized orbit. The S-polarized light is incident on the plane reflecting mirror 32 through a chopper device (strictly, a chopper plate) 30 as a blocking means. The chopper device 30 is for intermittently blocking (chopping) the incidence of S-polarized light on the planar reflecting mirror 32, and the cutoff frequency f is set to, for example, f = several [Hz] by the chopper controller 33. It can be arbitrarily changed within a range of 200 [Hz].

  The S-polarized light incident on the plane reflecting mirror 32 is reflected by the plane reflecting mirror 32, reflected by another plane reflecting mirror 34, and then second projection means provided separately from the liquid crystal shutter 20 described above. Is incident on the incident surface (the lower surface in FIG. 1) of the liquid crystal shutter. The liquid crystal shutter 28 has the same specifications as the liquid crystal shutter 20 described above, and a second control signal is given to the liquid crystal shutter 28 from the liquid crystal controller 22 described above. Then, when the second control signal is given, the liquid crystal shutter 28 has a shutter pattern that is exactly opposite to the liquid crystal shutter 20 described above. Specifically, as shown in FIG. Then, a shutter pattern is formed in which only the portion 62 corresponding to the shielding region 52 on the liquid crystal shutter 20 side (FIG. 3) is a transmission region and the other portion 64 is a shielding region.

  Therefore, only the light incident on the transmission region 62 out of the S-polarized light incident on the incident surface of the liquid crystal shutter 28 is transmitted through the liquid crystal shutter 28 and is emitted from the exit surface (the upper surface in FIG. 1). It is emitted straight. On the other hand, the light incident on the shielding region 64 is not emitted. When the position of the shielding area 52 on the liquid crystal shutter 20 side is changed, the position of the transmission area 62 on the liquid crystal shutter 28 side is also changed in conjunction with this.

  The S-polarized light that has passed through the liquid crystal shutter 28 (emitted from the emission surface of the liquid crystal shutter 28) is incident on the polarizing prism 24 as the above-described combining means. Here, the incident angle of S-polarized light with respect to the polarizing prism 24 is perpendicular to the incident angle of P-polarized light with respect to the polarizing prism 24. Accordingly, the S-polarized light incident on the polarizing prism 24 is emitted from the polarizing prism 24 in a synthesized state called P-polarized light incident on the polarizing prism 24, and then passes through the magnifying optical system 26, thereby passing through the eye to be examined. Projected on. The distance from the eye to be examined to the exit surface of the liquid crystal shutter 28 is equivalent to the distance from the subject eye to the exit surface of the liquid crystal shutter 20 described above. Therefore, when the focus adjustment is performed so that the eye to be examined and the exit surface of the liquid crystal shutter 20 are conjugated as described above, the subject eye is naturally conjugated to the exit surface of the liquid crystal shutter 28 as well. .

  In this way, the P-polarized light transmitted through the liquid crystal shutter 20 and the S-polarized light transmitted through the liquid crystal shutter 20 are projected onto the subject eye in a combined state, whereby the following image is presented to the subject eye. Is done. That is, when the S-polarized light is not blocked by the above-described chopper device 30, a square image with brightness corresponding to the luminance of the light source 12 is presented over the entire surface as shown in FIG. On the other hand, when the S-polarized light is blocked by the chopper device 30, as shown in FIG. 5B, a circular target 70 corresponding to the blocking area 52 and the transmission area 62 appears in the rectangular image. In other words, an image is presented in which only the portion of the target 70 is missing. Then, the images shown in FIGS. 5A and 5B are alternately presented in a cycle corresponding to the cutoff frequency f by the chopper device 30, and as a result, the target 70 is blinked.

In the visual field inspection, whether or not the visual target 70 can be visually recognized by the eye to be examined is checked in the state where the visual target 70 is blinkingly presented. At this time, the blinking cycle of the target 70 is appropriately changed by adjusting the cut-off frequency f described above, or the brightness of the background 72 surrounding the target 70 (in other words, the brightness of the target 70 by adjusting the luminance of the light source 12). A more detailed visual field inspection is performed by appropriately changing the relative brightness between the lighting brightness and the brightness of the background 72. Although not shown in the figure, in this visual field inspection, in addition to the visual target 70, a fixation target (gaze point) for fixing the eye to be examined is also presented.

  Here, the brightness of the visual target 70 is equal to the brightness of the background 72 or lower than the brightness of the background 72. That is, the visual target 70 is presented with a brightness at least lower than the background 72. Therefore, even if the optotype 70 is presented to the eye to be examined, the amount of light incident on the eye to be examined does not increase. In this respect, the amount of light incident on the eye to be examined is instantly presented to the eye to be examined. Compared with the above-described conventional technique in which the increase in the eye is suppressed, the stimulation to the eye to be examined is suppressed.

  Thus, according to the first embodiment, since the stimulus to the subject eye due to the presentation of the optotype 70 to the eye to be examined is suppressed, for example, the moment when the optotype 70 is presented is the optotype 70. The probability of misrecognizing that it is blinking is reduced, and as a result, a test result with higher reliability than in the past can be obtained. In particular, since the visual field inspection is a so-called subjective inspection in which the inspection proceeds based on the subjectivity of the subject, it is extremely effective to reduce misrecognition by the subject in such a visual field inspection. In other words, the liquid crystal shutter 20 for presenting the background 72 and the liquid crystal shutter 28 for presenting the target 70 are in a complementary relationship with each other, and one light source 12 is provided for these two liquid crystal shutters 20 and 28. There is no need to adjust the brightness of the visual target 70 and the background 72.

  Note that the visual field to be examined in the first embodiment (that is, the angle of view of the image shown in FIG. 5 presented to the eye to be examined) is, for example, about 60 degrees in each of the horizontal direction and the vertical direction. The distance from the exit surfaces of the liquid crystal shutters 20 and 28 (that is, the virtual image surface of the image presented to the subject's eye) to the subject's eye is, for example, about 300 [mm] (so-called reading distance). Further, the fixation target described above may be formed by the liquid crystal shutters 20 and 28 as well as the inspection target 70, or may be separately formed by other means. In addition to the liquid crystal shutters 20 and 28, the target 70 and the target for fixation may be formed by using, for example, the same means as the micromirror device in the prior art.

  And although the chopper device 30 is disposed between the polarizing prism 18 as the separating means and the plane reflecting mirror 32, it is not limited to this. For example, the chopper device 30 is disposed between the plane reflecting mirrors 32 and 34, between the plane reflecting mirror 34 and the liquid crystal shutter 28, and between the liquid crystal shutter 28 and the polarizing prism 24 as a combining unit. May be.

  Further, instead of the chopper device 30, for example, the transmission region 62 of the liquid crystal shutter 28 is intermittently set as a blocking region, that is, by alternately forming the transmitting region 62 and the blocking region, the S-polarized light is blocked, As a result, the target 70 may be blinked. In this way, the chopper device 30 and the chopper controller 33 can be excluded from the configuration of FIG.

  Further, for example, a colored filter may be inserted between the collimator lens 16 and the polarizing prism 18. In this way, the color of the visual target 70 and the background 72 presented to the eye to be examined can be changed, and a more detailed examination can be performed. In this case, it is desirable that the filter of any color can be easily switched. The place where the color filter is inserted is not limited to between the collimator lens 16 and the polarizing prism 18, but may be between the light source 12 and the collimator lens 16, for example. However, it is desirable to insert such a color filter (optical filter) at a place where the light is parallel light. Further, the colors of the visual target 70 and the background 72 can be arbitrarily changed by replacing the color filters with the liquid crystal shutters 20 and 28 as so-called color type liquid crystal shutters.

  The shape of the visual target 70 (the blocking area 52 and the transmission area 62) is not limited to a circle. For example, a shape other than the circle, such as an ellipse, a quadrangle, a triangle, and a star, may be used. Further, the size of the visual target 70 may be arbitrarily changed.

  Further, in the first embodiment, the perimeter 10 has been described as an example, but the present invention can be applied to an inspection apparatus (retinal disease apparatus or the like) other than the perimeter 10. In this case, according to the inspection purpose (type of inspection apparatus), for example, as shown in FIG. 6, a plurality of targets 70 may be presented. Further, as shown in FIG. 7, a linear visual target 70 may be presented. The length and thickness, line type (dotted line, alternate long and short dash line, etc.), number, stretching direction (angle), type (straight line, curved line, etc.), etc. can be arbitrarily changed. It is good.

Further, for example, a neutral density (ND) filter for reducing P-polarized light is provided between the polarizing prism 18 and the liquid crystal shutter 20 in FIG. 1 or between the liquid crystal shutter 20 and the changing prism 24. The brightness of only the background 72 may be appropriately reduced. Thus, when the target 70 is not turned with (FIG. 5 (a state of)), and (the state of FIG. 5 (b)) when the optotype 70 is lit, the entire image of the The difference in luminance can be reduced, and as a result, the stimulus to the eye to be examined can be further alleviated.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  As shown in the figure, the perimeter 100 according to the second embodiment excludes the chopper device 30 and the chopper controller 33 in the configuration of FIG. 1 described above, and also includes a light source 102, a collimator lens 104, and two polarizing plates. 106, 108, a half-wave plate 110 and a blinking controller 112 are provided. Since the other configuration is the same as that of FIG. 1, the same reference numerals are given to the same parts, and detailed description thereof is omitted.

  The light source 102 newly provided in the second embodiment is of the same specification (standard) as that of the other light source 12, that is, for presenting the background 72. That is, the light output from the light source 102 is corrected to parallel light by the collimator lens 104 and then incident on the polarizing plate 106. The polarizing plate 106 transmits only S-polarized light (two-dot chain line arrow) out of the incident light. Then, the S-polarized light transmitted through the polarizing plate 106 is incident on the polarizing prism 18.

  Since the polarizing prism 18 has the optical characteristics as shown in FIG. 2 described above (particularly the reflection characteristics shown in FIG. 2A), the S-polarized light incident on the polarizing prism 18 is in the incident direction. Is reflected toward the right angle. The reflected S-polarized light passes through the liquid crystal shutter 20 (transmission region 54) and then enters the half-wave plate 110.

  The half-wave plate 110 converts incident S-polarized light into P-polarized light (solid arrow). The P-polarized light converted by the half-wave plate 110 is thereafter projected onto the eye to be examined through the polarizing prism 24 and the magnifying optical system 26 in the same manner as in FIG.

  On the other hand, another light source 12 is for presenting the visual target 70. That is, the light output from the light source 12 is corrected to parallel light by the collimator lens 16 and then incident on the polarizing plate 108. The polarizing plate 108 transmits only the S-polarized light (dotted arrow) in the incident light, like the polarizing plate 106 described above. Then, the S-polarized light transmitted through the polarizing plate 108 is incident on the polarizing prism 18.

  The polarizing prism 18 reflects the S-polarized light incident from the polarizing plate 108 in a direction perpendicular to the incident direction. Then, the reflected S-polarized light is incident on the plane reflecting mirror 32, and thereafter is incident on the polarizing prism 24 through the plane reflecting mirror 34 and the liquid crystal shutter 28 in the same manner as in FIG. In the synthesized state, the light is projected through the magnifying optical system 26 onto the eye to be examined.

  The brightness of the two light sources 12 and 102 is adjusted by a common brightness controller 14. However, a blinking controller 112 is provided between the light source 12 for presenting the target 70 and the luminance controller 14 in order to cause the target 70 to blink. That is, the blinking controller 112 causes the light source 12 to blink by intermittently stopping the supply of power from the luminance controller 14 to the light source 12, and thus the visual target 70 to blink. The blinking period of the visual target 70 can be arbitrarily changed within the same range as in the first embodiment by the control of the blinking controller 112.

  It can be easily understood that the perimeter 100 according to the second embodiment configured in this way also has the same operations and effects as the perimeter 10 according to the first embodiment. That is, an accurate visual field inspection can be performed also by the second embodiment.

  In the second embodiment, the light source 12 for presenting the target 70 and the light source 102 for presenting the background 72 are provided separately, but these light sources 12 and 102 have the same specifications. In addition, the luminance is adjusted by the common luminance controller 112. Therefore, basically, it is not necessary to adjust the brightness of the visual target 70 and the background 72 as in the first embodiment.

  When FIG. 2 showing the configuration of the second embodiment is compared with FIG. 1 showing the configuration of the first embodiment, the second embodiment seems to be more complicated in structure. However, in the second embodiment, a relatively large component called the chopper device 30 (because it includes a chopper plate, a motor, etc.) is excluded. The second embodiment is more advantageous than the first embodiment.

  Next, a third embodiment of the present invention will be described with reference to FIG.

  As shown in the figure, the perimeter 200 according to the third embodiment has one polarizing prism 18, two plane reflecting mirrors 32 and 34, and a half-wave plate 110 in the configuration shown in FIG. And a polarizing plate 202 for extracting P-polarized light is provided instead of the polarizing plate 106 for extracting S-polarized light.

  That is, in the third embodiment, the light output from the light source 102 for presenting the background 72 is corrected to parallel light by the collimator lens 104 and then enters the polarizing plate 202. The polarizing plate 202 transmits only the P-polarized light (solid arrow) in the incident light. Then, the P-polarized light transmitted through the polarizing plate 202 is incident on the polarizing prism 18 through the liquid crystal shutter 20, and thereafter, to the eye to be examined through the polarizing prism 18 and the magnifying optical system 26 in the same manner as in FIG. Projected.

  On the other hand, the light (flashing light) output from the light source 12 for presenting the target 70 is corrected to parallel light by the collimator lens 16 and then enters the polarizing plate 108. The polarizing plate 108 transmits only S-polarized light (dotted arrow) among the incident light. Then, the S-polarized light transmitted through the polarizing plate 108 is incident on the polarizing prism 24 through the liquid crystal shutter 28, and thereafter is synthesized with the P-polarized light in the same manner as in FIG. Projected on.

  The control of each light source 12 and 102 is the same as in the case of FIG. That is, the light source 12 for presenting the target 70 is controlled to blink. The lighting of the light source 102 for presenting the background 72 is controlled.

  It is easy to understand that the perimeter 200 according to the third embodiment configured in this way also has the same operations and effects as the perimeter 10 of the first embodiment and the perimeter 100 of the second embodiment described above. I can do it. Moreover, the perimeter 200 of the third embodiment has a simpler configuration than that of the perimeter 100 of the second embodiment, so that the perimeter 200 as a whole can be further reduced in size and cost. Can do.

It is a figure which shows schematic structure of 1st Embodiment of this invention. It is a figure which shows the optical characteristic of the polarizing prism in the said 1st Embodiment. FIG. 3 is an illustrative view showing a state of a liquid crystal shutter for background presentation in the first embodiment. It is an illustration figure which shows the state of the liquid-crystal shutter for a target presentation in the 1st embodiment. It is an illustration figure which shows the example of an image | video presented to a to-be-examined eye in the 1st Embodiment. It is an illustration figure which shows another example of the target in the said 1st Embodiment. It is an illustration figure which shows another example of the optotype in the said 1st Embodiment. It is a figure which shows schematic structure of 2nd Embodiment of this invention. It is a figure which shows schematic structure of 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Perimeter 12 Light source 14 Luminance controller 18, 24 Polarizing prism 20, 28 Liquid crystal shutter 22 Liquid crystal controller 30 Chopper device

Claims (11)

In an ophthalmic examination apparatus that presents a test target to the eye to be examined and inspects the eye based on the visual recognition status of the target by the eye to be examined.
In order to alternately present the target in a first mode having the same brightness as the background of the target and a second mode having a lower brightness than the background ,
One light source means;
An optical path forming means for forming two optical paths between the light source means and the eye to be examined;
Background presenting means for presenting the background to the eye to be examined by a first light beam provided from one of the two optical paths and traveling along the one optical path;
An optotype presenting means for presenting the optotype to the eye to be examined by a second light beam from the light source means provided on the other of the two optical paths,
An ophthalmic examination apparatus comprising: The background presentation means has a first incident surface on which the first light beam is incident, and the first projection means projects the first light beam incident on the first incident surface onto the eye to be examined according to a first control signal. And the first light beam incident on the portion corresponding to the background of the first incident surface is projected onto the eye to be examined and the first light beam incident on the portion corresponding to the target is not projected. First control means for generating the first control signal as described above,
The optotype presenting means has a second incident surface on which the second light beam is incident, and projects the second light beam incident on the second incident surface onto the eye to be examined according to a second control signal. And the second light beam incident on the portion corresponding to the target of the second incident surface is projected onto the eye to be examined and the second light beam incident on the portion corresponding to the background is unprojected. Second control means for generating the second control signal, and invalidation means for intermittently invalidating the projection of the second light beam on the eye to be examined by the second projection means,
The ophthalmic examination apparatus according to claim 1 . The ophthalmic examination apparatus according to claim 2 , wherein the invalidating unit includes a blocking unit that intermittently blocks the second light beam projected onto the eye to be examined by the second projecting unit. In an ophthalmic examination apparatus that presents a test target to the eye to be examined and inspects the eye based on the visual recognition status of the target by the eye to be examined.
In order to alternately present the target in a first mode having the same brightness as the background of the target and a second mode having a lower brightness than the background,
Two light source means of the same specification,
A background presenting means for presenting the background to the eye to be examined by a first light beam provided in a first optical path from one of the two light source means to the eye to be examined;
An optotype presenting means for presenting the optotype to the eye to be examined by a second light beam provided in a second optical path from the other of the two light source means to the eye to be examined;
An ophthalmic examination apparatus comprising: The background presentation means has a first incident surface on which the first light beam is incident, and the first projection means projects the first light beam incident on the first incident surface onto the eye to be examined according to a first control signal. And the first light beam incident on the portion corresponding to the background of the first incident surface is projected onto the eye to be examined and the first light beam incident on the portion corresponding to the target is not projected. First control means for generating the first control signal as described above,
The optotype presenting means has a second incident surface on which the second light beam is incident, and projects the second light beam incident on the second incident surface onto the eye to be examined according to a second control signal. And the second light beam incident on the portion corresponding to the target of the second incident surface is projected onto the eye to be examined and the second light beam incident on the portion corresponding to the background is unprojected. Second control means for generating the second control signal, and invalidation means for intermittently invalidating the projection of the second light beam on the eye to be examined by the second projection means,
The ophthalmic examination apparatus according to claim 4 . The ophthalmic examination apparatus according to claim 5 , wherein the invalidating unit includes a stopping unit that intermittently stops generation of the second light beam by the other light source unit. The ophthalmic examination apparatus according to any one of claims 1 to 6 , further comprising cycle changing means for arbitrarily changing a cycle for switching between the first mode and the second mode. Further comprising shape changing means for arbitrarily changing the shape of the optotype, ophthalmologic examination apparatus according to any one of claims 1 to 7. The ophthalmic examination apparatus according to any one of claims 1 to 8 , further comprising color changing means for arbitrarily changing the colors of the background and the target. It said in the background and the first aspect further comprising a brightness changing means for arbitrarily changing the respective brightness of the target, ophthalmologic examination apparatus according to any one of claims 1 to 9. The ophthalmic examination apparatus according to any one of claims 1 to 10 , which is a perimeter for measuring the visual field of the eye to be examined.

Images