JPH0236259B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a screen that is illuminated simultaneously by two projectors, where a visual target is placed in the optical path of one of the projectors and the luminous intensities of both projectors are combined with each other; The luminous intensity of one projector increases in the same way as the luminous intensity of the other projector decreases,
The present invention also relates to a mesopic and glare sensitivity test device having a connectable glare light source placed next to the field of view in the screen.

A device of the above type is known from German Patent No. 1 282 847. These devices help confirm mesopic vision, glare sensitivity, and accommodation.

These devices are advantageously used primarily to test a driver's suitability for night driving. This is because the situation when driving at night is fundamentally different from that during normal daytime driving, and vision is clearly impaired.

However, the test using the known device is comparatively expensive since it is carried out in a completely darkened room and the subject must have a distance of 3 meters to the screen.

An object of the present invention is to use the above-mentioned type of apparatus so that the examination can be carried out in a normally illuminated room, the distance between the subject and the screen can be reduced, and the screen and projector can be integrated into one apparatus. It is to configure the system so that it can be placed.

According to the present invention, a screen is placed at the focal point of a concave mirror, and a semi-transparent mirror that is tilted with respect to the optical axis of the concave mirror is placed between the concave mirror and the screen facing the subject's eyes. The solution is that the device has an aperture in the extension of the visual axis that allows unobstructed viewing, and that this aperture is equipped with a filter to attenuate the light incident from the outside.

In the examination device according to the invention, the subject sees a distance image without the customary disturbances due to convergence and accommodation errors caused by the device. The subject gazes at the test image into the device at infinity, since the semi-transparent mirror causes the target and the peripheral field to be incident on the observer's eye together. Due to the relatively short distance between the screen and the concave mirror, the device according to the invention requires small overall dimensions.

Especially when testing mesopic vision, it is important to recognize the contrast sensitivity rather than the size of the optotype.
In the device according to the invention, the two light paths form a visual target with a clear peripheral field, and the contrast level can be varied continuously, the overall change being constant. The test is carried out by the subject's recognition of the visual target, generally the break position of the Landolt ring, at each contrast level, and in this case also by using two different intensities of glare or by using two different intensities of glare to examine the glare sensitivity. It can be done without Furthermore, based on the confirmation of a clear decline in visual target recognition ability,
Testing for cataract patients is also possible.

An embodiment of the invention will now be explained in more detail with reference to the drawings: The device for testing mesopic vision and glare sensitivity consists of a casing 1 with a stand 2 . The subject (whose two eyes 3, 4 are shown) looks into the device through an opening 5 in the casing 1. A cover 6 is provided that extends over the eyes to block the influence of light coming from outside. Directly opposite the opening 5, another opening 7 is arranged in the casing 1 of the device. This aperture 7 has the purpose of giving the subject the impression that the examination is being carried out in an open room, thereby eliminating accommodation or adaptation of the eye which could result in measurement errors. A filter 8 can be pivoted into this opening in order to reduce the incidence of light coming from outside. Furthermore, since the filter 8 is transparent, the subject can gaze outward through the device unhindered.

The concave mirror 10 has its optical axis 11 arranged at right angles to the optical path 9. A screen 12 is arranged at the focal point of the concave mirror 10, which is illuminated by two projectors 13, 14 each having a clamp 15 and a condenser lens 16.

Another projector 1 inside the casing 1
7 is arranged, which serves to image the two viewing light spots 18, 19. This gazing light spot is shown in FIG.

Two deflection mirrors 21 and 22 are arranged in the light path 20 of the projector 14, which deflect the light of the projector 14 onto the screen 12. These mirrors are necessary in order to be able to assemble relatively low-height projectors and to avoid interference of the various projector beams. For the same reason, the optical path 23 of the projector 13
Two turning mirrors 24 and 25 are arranged inside,
Two turning mirrors 24 and 28 are arranged in the optical path 26 of the projector 17.

A pinhole diaphragm 29 is simply placed in front of the projector 14, and an optotype 30 is placed in front of the projector 13. This optotype is shown on the right side of FIG. The circle shown on the left side of FIG. 3 indicates that the projector 14 only emits light of a particular light power. The vertical chain line indicates that the projector 13 illuminates the peripheral field indicated by visual targets 30 and 43, and the projector 14 illuminates the peripheral field 43.
Indicates that only the area is illuminated.

Filters 31 and 32 are arranged in the optical path 20 of the projector 14 and in the optical path 23 of the projector 13, and these filters are mutually arranged so that the sum of the intensities of the light hitting the screen 12 from the projectors 13 and 14 is always equal to 100%. It is harmonized. When the intensity of the light from the projector 14 increases, the intensity of the light from the projector 13 decreases accordingly. Since it is sufficient to change the light intensity of both projectors to 8 stages, the filters can simply be replaced accordingly.

Further filters 33, 34a can be inserted into the beam paths 20, 23 behind each of the mirrors 21, 24, which further reduce the light intensity. These two filters are connected, for example, when simulating to the subject the difference between a wet road and a dry road.

Further, into both optical paths 20 and 23, necessary for image formation on the screen 12 and projector 1
Projection lenses 35 and 36, which are parts 3 and 14, are inserted.

Since glare sensitivity is examined using glare, when a glare light source is connected, the subject may not be able to recognize the visual target due to the sharp contrast.
For this purpose, auxiliary means are additionally provided for indicating to the subject the part of the examination field to be observed. It consists of two red light spots (FIG. 4) that mark above and below the part where the visual target is to be recognized. The light spots 17 and 18 are imaged on the screen 12 by the projector 17 and a sign 37 placed in front of it when the lamp belonging to the projector is turned on, so that the subject can see the dazzling light source 38.
Even if they are connected for a short time, it is possible to gaze at a visual target (Landolt ring) between these two light points. The glare light source consists of a lamp and a condenser lens in a known manner.

A semi-transparent mirror 39 is inserted into the optical path 9 of the observer's eyes 3, 4 at an angle of 45° to the optical axis 11 (FIG. 1). The concave mirror 10 images an optotype (Landolt ring) 30 projected on the screen 12 so that it appears at an infinite distance. A semi-transparent mirror 39 directs this test image in optical paths 40/41, 41/42 towards the viewer (FIG. 3).

Projection optical paths 20, 23 focused on the same test image
By adjusting the filters 31 and 32 during the process, the brightness difference between the peripheral field 43 and the optotype 30 is changed stepwise, and the mesopic vision of the subject is adjusted when the brightness of the peripheral field is constant. Check.

To test glare sensitivity, the glare light source 38 is alternately connected and disconnected for short periods of time. Since the dazzling light source appears to the observer to be near the inspection field 43, inspection can be performed regardless of the presence or absence of dazzling light.
In order to simulate wet and dry roads, filters 34, 34a are additionally connected in the beam paths 20, 23 (FIG. 3) to adjust the brightness of the left and right test images as required. Change it.

For examining mesopic vision and glare sensitivity, a device constructed according to the invention has relatively small dimensions;
Can be used indoors with normal lighting.
A filter 8 placed in front of the opening 7 creates the possibility of attenuating the light entering the device or into the eye from the outside.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 shows an apparatus constructed according to the present invention, and FIG.
2 is a sectional view taken along the - line in FIG. 1; FIG. 3 is a side sectional view of the device shown in FIG. 1; FIG. 4 is a sectional view taken along the - line in FIG. 3. It is a diagram. 1... Casing, 2... Stand, 3, 4... Eyes,
6... Cover, 5, 7... Opening, 8... Filter, 9... Optical path, 10... Concave mirror, 11... Optical axis, 12... Screen, 13, 14... Projector, 15... Lamp, 16...Condensing lens, 1
7... Projector, 18, 19... Gazing light point,
20... Optical path, 21, 22... Turning mirror, 23
...Optical path, 24, 25, 27, 28... Turning mirror, 30... Visual target, 33, 34a... Filter,
35, 36...projection lens, 38...dazzling light source,
40, 41, 42... light path.

Claims (1)

[Claims] 1. It has a screen that is illuminated simultaneously by two projectors, in which case a visual target is placed in the optical path of one projector, and the luminous intensity of both projectors is combined with each other, and the luminous intensity of one projector is increases in the same way as the luminous intensity of the other projector decreases, or decreases in the same manner as the luminous intensity of the other projector decreases, and a connectable glare light located next to the field of view in the screen. In a mesopic vision and glare sensitivity inspection device having a light source, a screen 12 is placed at the focal point of the concave mirror 10, and the concave mirror 1 is placed between the concave mirror 10 and the screen 12.
semi-transparent mirror 3 tilted with respect to the optical axis 11 of 0;
9 is placed opposite the subject's eyes, the device has an aperture 7 in the extension of the visual axis allowing unobstructed perspective, and the aperture 7 has a filter 8 for attenuating light incident from the outside. A testing device for mesopic vision and glare sensitivity, characterized by comprising: 2. The device according to claim 1, wherein at least one gaze light spot 18, 19 near the optotype 30 is projected onto the screen 12 by another projector 17. 3 Visual target 30 and peripheral field 33 on screen 12
Optical path 2 of projectors 13 and 14 for creating
0, 23 into which another filter 33, 34 can be connected.
Apparatus described in section.