Display device

• US 5,461,400 A
• Filed: 01/04/1995
• Issued: 10/24/1995
• Est. Priority Date: 01/24/1992
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ishii, Yutaka, Yamamoto, Yoshitaka
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): LAO, LUNYI
• Application Number:
  US08/368,750
• Time in Patent Office: 293 Days
• Field of Search: 359/42, 359/45, 359/72, 359/55, 345/87, 345/104, 345/75, 345/82, 345/100, 345/173, 345/175, 345/179, 345/180, 345/182, 345/183
• US Class Current: 345/182
• CPC Class Codes: G02F 1/135 Liquid crystal cells structurally associated with a photoconducting or a ferro-electric layer, the properties of which can be optically or electrically varied G02F1/133348 takes precedence
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means

Abstract

A display device provides a liquid crystal 41 served as a display medium, a plurality of pixel electrodes for driving the liquid crystal 41, a plurality of lower electrodes x₁ to x₁₂₈ and upper electrodes Y₁ to Y₁₀₀ ranged in the row or column direction, a plurality of photoconductive elements S^X₁,1 to S^X₁₂₈,100 and S^Y₁,1 to S^Y₁₂₈,100 provided on each of these pixel electrodes for electrically connecting or disconnecting the signal lines with or from the pixel electrodes, and a plurality of linear luminous bodies X₁ to X₁₂₈ and Y₁ to Y₁₀₀ provided in the column and row directions in a manner to selectively apply light to the photoconductive elements and control connection or disconnection of the photoconductive elements.

Claims

1. A display device comprising:

a display medium disposed between two substrates;

a plurality of pixel electrodes disposed on each of said substrates for driving said display medium;

a plurality of signal lines ranged in the row or column direction on said each substrate;

a plurality of photoconductive elements provided respectively on a plurality of said pixel electrodes of at least one substrate for electrically connecting said signal lines with said pixel electrodes selectively;

a plurality of linear luminous bodies arranged in the column or row direction in said at least one substrate in a manner to selectively apply light to said photoconductive elements in order to control electrical conductivity of said photoconductive elements;

light sensing means disposed at one end of each of a plurality of said linear luminous bodies and for sensing a location of a light incident to at least one of said linear luminous bodies; and

a light pen for designating a position on a display surface, having light emitting means for emitting a light with a wavelength out of range of ambient light wavelengths to be entered into said at least one of said linear luminous bodies, said wavelength of light emitted by the light emitting means of said light pen corresponding with wavelength of light to which said light sensing means responds.

2. A display device according to claim 1, wherein said display medium is liquid crystal.

3. A display device according to claim 1, wherein said pixel electrodes are arranged in matrix.

4. A display device according to claim 1, wherein said signal lines are arranged to be substantially perpendicular to said linear luminous bodies in one substrate.

5. A display device according to claim 1, wherein each of said photoconductive elements is provided in a manner to bridge between one data line and one pixel electrode.

6. A display device according to claim 1, wherein each of said luminous bodies is made of amorphous silicon.

7. A display device according to claim 1, wherein each of said luminous bodies includes an EL element and a linear light wave guide having one end connected to said EL element.

8. A display device according to claim 1, wherein said two substrates are juxtaposed to each other in a manner that the signal lines of one substrate is perpendicular to the signal lines of the other substrate.

9. A display device according to claim 1, wherein said signal lines of each substrate are shortcircuited to form common electrode.

10. A display device according to claim 9, further comprising:

voltage applying means for applying between two common electrodes a voltage higher than a threshold voltage of said display medium; and

means for making sequentially the luminous bodies of one substrate luminous and making the luminous bodies of the other substrate luminous in a manner to match a desired display pattern.

11. A display device according to claim 1, further comprising:

display control means for displaying a location sensed by said light sensing means through said display medium.

12. A display device according to claim 1, wherein said light emitted from said light pen has a wavelength not affecting said photoconductive elements.

13. A display device according to claim 1, wherein said light pen includes means for flickering the light output of said light pen at a particular frequency.