Display device having display and imaging pixels sandwiched between same substrates

• US 6,040,810 A
• Filed: 01/07/1997
• Issued: 03/21/2000
• Est. Priority Date: 01/08/1996
• 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: Nishimura, Toshio
• Primary Examiner(s): NGUYEN, CHANH DUY
• Application Number:
  US08/779,529
• Time in Patent Office: 1,169 Days
• Field of Search: 345/87, 345/55, 345/197, 345/205, 345/206, 345/84, 348/62, 348/20, 348/18, 348/14, 348/15, 348/19, 349/41, 349/50, 349/24, 349/28, 349/13, 349/42, 349/59, 349/62, 349/29, 455/556, 455/557, 385/115, 385/116, 327/403, 327/404
• US Class Current: 345/87
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/367 with a nonlinear element in series with the liquid crystal cell, e.g. a diode, or M.I.M. element
• CPC Class Codes: H01L 27/14831 Area CCD imagers
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 7/144 camera and display on the same optical axis, e.g. optically multiplexing the camera and display for eye to eye contact

Abstract

In a picture telephone, an apparatus is provided which images the face of an operator in a natural manner for a conversation, with an eye height at which the operator looks at an image expressing a partner of the conversation. A number of photodiodes are disposed each adjacent to each pixel electrode, on surfaces facing each other of a pair of substrates between which a liquid crystal of a transmission type active matrix liquid crystal display apparatus is interposed. Outputs from the respective photodiodes are read out by a so-called inter-line transmission method which utilizes a scanning function of a CCD (charge coupled device).

Claims

1. A television communication apparatus comprising:

(a) a displaying/imaging apparatus disposed to face an operator comprising;

a pair of spaced apart substrates which define an internal volume therebetween, at least one of the substrates being light transmissive;

a matrix of pixel electrodes mounted on a volume-oriented side of at least one of the substrates;

at least one light-receiving element of an imaging device mounted within the internal volume;

a discrete light receiving electrode having means for adjusting the amount of light received by the light-receiving element;

a dielectric interposed within the internal volume, the dielectric providing a display function in accordance with activation of the pixel electrodes;

(b) image driving means for receiving an image signal through a communication line and providing the pixel electrodes with the image signal to perform a display operation;

(c) a speaker;

(d) an audio driving circuit for receiving an audio signal through the communication line and driving the speaker;

(e) a microphone; and

(f) transmitting means for transmitting outputs from the outputting means and the microphone to the communication line.

2. A combined display and imaging apparatus comprising:

a pair of spaced apart substrates which define an internal volume therebetween, at least one of the substrates being light transmissive;

a matrix of display elements mounted on a volume-oriented side of at least one of the substrates;

at least one light-receiving element of an imaging device mounted within the internal volume;

a discrete light receiving electrode having means for adjusting the amount of light received by the light-receiving element;

a dielectric which is interposed within the internal volume, the dielectric providing a display function in accordance with activation of the display elements.

3. The apparatus of claim 2, wherein the pair of substrates transmits light and a light shielding layer is formed in the rear of the light-receiving element.

4. The apparatus of claim 2, wherein both the matrix of display elements and the at least one light-receiving element of the imaging device are mounted on a rear of one of the substrates.

5. The apparatus of claim 2, wherein the dielectric is a liquid crystal, wherein the volume-oriented side of at least one of the substrates has:

a plurality of gate lines formed thereon to extend in a first direction;

a plurality of source lines formed thereon to extend in a second direction, the second direction being perpendicular to the first direction;

an aperture being bounded between two adjacent ones of the gate lines and two adjacent ones of the source lines, and

wherein within the aperture are provided;

a pixel electrode which causes the liquid crystal to attain a display function; and

a discrete light-receiving element.

6. The apparatus of claim 5, wherein within the aperture is also provided a switching element connected to one of the gate lines and to one of the source lines for activating the pixel electrode.

7. The apparatus of claim 6, wherein plural switch elements and plural pixel electrodes are provided for corresponding plural apertures, and wherein the switch elements are

thin film transistors provided so as to correspond to intersections of the gate lines and the source lines,

each of the thin film transistors including a source electrode which is connected to one of the source lines, a gate electrode which is connected to one of the gate lines, and a drain electrode which is connected to one of the pixel electrodes,

the source electrode and the drain electrode of each thin film transistor being brought into conduction on application of a voltage of one level to the gate lines, and being brought out of conduction on application of a voltage of another level to the gate lines;

a common electrode confronting the pixel electrodes is formed on the other of the surfaces facing each other of the pair of substrates; and

means for applying a displaying voltage equal to or larger than a threshold value which activates the dielectric element and for applying a control voltage which brings the thin film transistors into conduction or out of conduction, to the gate lines, is provided between the source lines and the common electrode.

8. The apparatus of claim 7, wherein the thin film transistors and the light-receiving elements are arranged between the source lines which are adjacent to each other in the column direction of the pixel electrodes so as to be adjacent to each other in the row direction of the pixel electrodes.

9. The apparatus of claim 7, wherein

on light-receiving surfaces of the light-receiving elements are formed discrete light-transmitting electrodes for adjusting a light-receiving amount,

the discrete electrodes are connected to the source lines,

a voltage is applied to the source lines during a displaying period and a period of adjusting the light-receiving amount which are set alternately, and

a voltage which keeps the thin film transistors out of conduction is applied to the gate lines during the period of adjusting the light-receiving amount.

10. The apparatus of claim 5, wherein within the aperture is also provided at least a portion of a readout device which is connected to the light-receiving element.

11. The apparatus of claim 10, wherein plural light-receiving elements are provided.

12. The apparatus of claim 11 wherein the readout device is a semiconductor device and comprises:

column shift registers for reading out the outputs from light-receiving elements of each column in a parallel manner and shifting the outputs as a serial bit in a column direction; and

a row shift register for sequentially deriving an output of each column shift register as a serial bit to a common output terminal for each column shift register.

13. The apparatus of claim 12, wherein the column registers and the row shift register are structured so that scanning using a charge coupled device is carried out.

14. The apparatus of claim 5, wherein discrete light-transmitting electrodes for adjusting a light-receiving amount are formed on light-receiving surfaces of the respective light-receiving elements, and the amount of light received via the dielectric element by the light-receiving surfaces is adjusted by changing a light transmittance depending on a voltage between the discrete light-receiving amount adjusting electrodes and the electrodes formed on the substrate confronting the substrate on which the light-receiving elements are formed.

15. The apparatus of claim 14, wherein lines for adjusting the light-receiving amount and the light-receiving elements are formed on one of the pair of substrates to be along and adjacent to the source lines, and

the discrete light-receiving amount adjusting electrodes are connected to the light-receiving amount adjusting lines.

16. The apparatus of claim 14, wherein

a distance of the discrete light-receiving amount adjusting electrodes from a common electrode is selected to be smaller than a distance of the pixel electrodes from the common electrode, and the discrete light-receiving amount adjusting electrodes are connected to the source lines;

and

a voltage is applied to the source lines during a displaying period and a period of adjusting the light-receiving amount which are set alternately, and the voltage applied during the period of adjusting the light-receiving amount is selected to be a value lower than the displaying voltage applied during the displaying period, which value does not activate the dielectric element existing between the pixel electrodes and the common electrode.

17. A combined display and imaging apparatus comprising:

a pair of spaced apart substrates which define an internal volume therebetween, at least one of the substrates being light transmissive;

a matrix of display elements mounted on at least one of the substrates;

at least one light-receiving element of an imaging device;

a discrete light-receiving electrode having means for adjusting the amount of light received by the light-receiving element;

a liquid crystal interposed within the internal volume;

wherein the at least one of the substrates has formed thereon;

a plurality of gate lines formed thereon to extend in a first direction;

a plurality of source lines formed thereon to extend in a second direction, the second direction being perpendicular to the first direction;

an aperture being bounded between two adjacent ones of the gate lines and two adjacent ones of the source lines, and

wherein within the aperture is provided;

a discrete one of the display elements of the matrix; and

a discrete light-receiving element.

18. The apparatus of claim 17, wherein within the aperture is also provided a switching element connected to one of the gate lines and to one of the source lines for activating the discrete one of the display elements of the matrix.

19. The apparatus of claim 17, wherein within the aperture is also provided at least a portion of a readout device which is connected to the light-receiving element.