Vision testing system for stereoscopic viewing by a test person

• US 5,638,082 A
• Filed: 10/25/1993
• Issued: 06/10/1997
• Est. Priority Date: 10/23/1992
• Status: Expired due to Term

• Current Assignee: Carl-Zeiss-Stiftung
• Original Assignee: Carl-Zeiss-Stiftung
• Inventors: Grimm, Wolfgang
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): LAO, LUNYI
• Application Number:
  US08/140,464
• Time in Patent Office: 1,324 Days
• Field of Search: 345/4, 345/5, 345/6, 345/7, 345/8, 345/32, 345/84, 345/87, 345/88, 345/102, 345/185, 345/201, 359/464, 359/465, 351/201, 351/215, 351/232, 351/239, 351/240, 348/42, 348/51, 348/58
• US Class Current: 345/6
• CPC Class Codes: G02B 30/25 using polarisation techniques
• CPC Class Codes: H04N 13/324 Colour aspects
• CPC Class Codes: H04N 13/334 using spectral multiplexing
• CPC Class Codes: H04N 13/337 using polarisation multiplexing
• CPC Class Codes: H04N 13/398 Synchronisation thereof; Control thereof

Abstract

An image display system comprises polarization spectacles having different polarization axes with or without λ/4-foils of both polarization lenses forward of the eyes of the person to be tested. The system of the invention further includes an image display device for generating light with a specific direction of polarization or a specific rotational direction of the circularly polarized light. The image display device comprises essentially at least one vectograph film and at least one image screen. This arrangement can so influence the light coming from the image screen that test figures or parts thereof can be seen by only one eye or by both eyes. If the image display system is to be used as a vision testing system and the test figures are to be changed, then there is a corresponding command of a drive circuit via a memory. The drive circuit drives the image screen in a suitable manner. A color display can be provided by making an appropriate modification to the image display device.

Claims

1. A vision testing system for stereoscopic viewing by a test person, the system comprising:

an image display emitting polarized light and having a plurality of image display elements for displaying respective images and said image display elements being arranged in said image display to have a fixed geometrical arrangement to each other;

a vectograph film disposed forward of said image display and having a plurality of polarization elements with each of said polarization elements completely covering at least one of said image display areas;

said polarization elements being arranged on said vectograph film in strip or checkerboard pattern;

each of said polarization elements defining a polarization axis and the respective polarization axes of each two mutually adjacent ones of said polarization elements being mutually perpendicular;

polarization spectacles with which the test person can view the image display through said vectograph film;

said polarization spectacles having two filter discs having respective polarization foils;

said polarization foils having respective polarization axes which are mutually perpendicular and one of said polarization axes of said polarization foils extending in the same direction as the polarization axes of a first portion of said polarization elements being assigned to one eye of the test person and the other one of said polarization axes of said polarization foils extending in the same direction as the polarization axes of a second portion of said polarization elements and being assigned to the other eye of the test person;

input means for effecting changes on said image display;

a drive circuit connected to said image display for individually driving each of said image display elements so as to permit separate test images to be formed for each eye of the test person;

a nonvolatile permanent memory for permanently storing a plurality of different ones of said test images to be displayed on said image display;

said nonvolatile permanent memory being addressable by said input means to transmit selected signals indicative of selected ones of said images to be displayed; and

,

said nonvolatile permanent memory being connected to said drive circuit for transmitting said selected signals to said image display elements for changing said images on said image display to said selected ones of said images.

2. The vision testing system of claim 1, said memory being in a computer.

3. The vision testing system of claim 2, said image display being a flat image screen.

4. The vision testing system of claim 3, said image display having a rearward side and said system further comprising at least one light source mounted at said rearward side for emitting light transilluminating said image display.

5. The vision testing system of claim 4, further comprising a switching device interposed between said light source and said input means;

and, said switching device being adapted to change the intensity of the light of said light source.

6. The vision testing system of claim 4, said image display being an LCD-display having a plurality of LCD-elements for generating a corresponding plurality of images in a fixed spatial relationship to each other;

and, said system further comprising a first additional polarization foil interposed between said light source and said LCD-display and having a polarization axis at 45°

to said polarization axes of said polarization elements of said vectograph film.

7. The vision testing system of claim 6, further comprising a second additional polarization foil interposed between said LCD-display and said vectograph film having a polarization axis which is perpendicular or parallel to said polarization axes of said first additional polarization foil.

8. The vision testing system of claim 6, said LCD-display being an LCD-display generating color images.

9. The vision testing system of claim 8, further comprising a first λ

/4-foil disposed forward of said vectograph film downstream of said light source; and

, a second λ

/4-foil disposed on said filter discs of said polarization spectacles.

10. The vision testing system of claim 9, said image display elements of said image display being adapted to display test figures for testing the vision of a test person.

11. The vision testing system of claim 1, said drive circuit and said input means being conjointly adapted to provide test figures selectably movable across said image display elements.

12. The vision testing system of claim 1, said drive circuit and said input means being conjointly adapted to drive individual ones of said image display elements.

13. The vision testing system of claim 1, said input means comprising a keyboard and a switching unit connecting said keyboard to said drive circuit.

14. A vision testing system for stereoscopic viewing by a test person, the system comprising:

an image display emitting polarized light and having a plurality of image display elements for displaying respective images and said image display elements being arranged in said image display to have a fixed geometrical arrangement to each other;

a vectograph film disposed forward of said image display and having a plurality of polarization elements with each of said polarization elements completely covering at least one of said image display areas;

said polarization elements being arranged on said vectograph film in strip or checkerboard pattern;

each of said polarization elements defining a polarization axis and the respective polarization axes of each two mutually adjacent ones of said polarization elements being mutually perpendicular;

polarization spectacles with which the test person can view the image display through said vectograph film;

said polarization spectacles having two filter discs having respective polarization foils;

said polarization foils having respective polarization axes which are mutually perpendicular and one of said polarization axes of said polarization foils extending in the same direction as the polarization axes of a first portion of said polarization elements being assigned to one eye of the test person and the other one of said polarization axes of said polarization foils extending in the same direction as the polarization axes of a second portion of said polarization elements and being assigned to the other eye of the test person;

input means for effecting changes on said image display;

a drive circuit connected to said image display for individually driving each of said image display elements so as to permit separate test images to be formed for each eye of the test person;

a nonvolatile permanent memory for permanently storing a plurality of different ones of said test images to be displayed on said image display;

said nonvolatile permanent memory being addressable by said input means to transmit selected signals indicative of selected ones of said images to be displayed;

said nonvolatile permanent memory being connected to said drive circuit for transmitting said selected signals to said image display elements for changing said images on said image display to said selected ones of said images;

said image display having a rearward side;

at least one light source mounted at said rearward side for emitting light transilluminating said image display;

color changing means for changing the color of said light emitted by said light source; and

,

a switching device connecting said input means to said color changing means for actuating said color changing means to change the color of the light emitted by said light source.