Display circuit with optical sensor

• US 20030234759A1
• Filed: 06/21/2002
• Published: 12/25/2003
• Est. Priority Date: 06/21/2002
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Bergquist, Johan
• Granted Patent: US 7,184,009 B2
• Time in Patent Office: Days
• US Class Current: 345/92
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 2360/142 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 2360/148 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters

Abstract

A combined input/output device having a display mode in which it operates as a matrix display and sensing mode in which it receives optical input, comprising multiple picture element circuits arranged as a matrix display and multiple optical sensors arranged as a sensor matrix. The optical sensors and pixel circuits are integrated on the same substrate and the control lines used for controlling the pixel circuits are advantageously re-used for controlling the optical sensors. A plurality of optical sensors are enabled at a time, thereby allowing for the discrimination of inputs by gesture.

Claims

1. An integrated circuit comprising:

a substrate;

a picture element circuit, for an active matrix display, integrated on the substrate and comprising a switching transistor having a first gate electrode; and

a phototransistor integrated on the substrate and comprising a second gate electrode electrically connected to the first gate electrode.

2. An integrated circuit comprising:

a substrate;

a first multiplicity of picture element circuits integrated on the substrate and arranged as a matrix display having a first plurality of rows and a second plurality of columns;

a first plurality of first conductive lines integrated on the substrate and arranged such that, each one of the first plurality of first conductive lines is associated with a different row of the matrix display and is connected to all the picture element circuits of its associated row;

a second plurality of second conductive lines integrated on the substrate and arranged such that each one of the second plurality of second conductive lines is associated with a different column of the matrix display and is connected to all the picture element circuits of its associated column;

a second multiplicity of sensors integrated on the substrate and arranged as a sensor matrix having a third plurality of rows and a fourth plurality of columns;

a third plurality of conductive lines integrated on the substrate and arranged such that each one the third plurality of conductive lines is associated with a different row of the sensor matrix and is connected to all the sensors of its associated row; and

a fourth plurality of conductive lines integrated on the substrate and arranged such that each one of the fourth plurality of conductive lines is associated with a different column of the sensor matrix and is connected to all the sensors of its associated column.

3. An integrated circuit as claimed in claim 2, wherein the third plurality of conductive lines is a third plurality of the first conductive lines.

4. An integrated circuit as claimed in claim 2, wherein the fourth plurality of conductive lines is a third plurality of the second conductive lines.

5. An integrated circuit as claimed in claim 2 further comprising a fifth plurality of third conductive lines integrated on the substrate and arranged such that each one of the fifth plurality of third conductive lines is associated with a different column of the sensor matrix and is connected to all the sensors of its associated column.

6. An integrated circuit as claimed in claim 2, wherein the matrix display is an active matrix display and each picture element circuit comprises a switching transistor.

7. An integrated circuit as claimed in claim 6, wherein each of the switching transistors is a thin film transistor.

8. An integrated circuit as claimed in claim 7, wherein each of the thin film transistor comprises hydrogenated amorphous silicon.

9. An integrated circuit as claimed in claim 2, wherein each sensor comprises a phototransistor.

10. An integrated circuit as claimed in claim 9, wherein each phototransistor is a thin film transistor.

11. An integrated circuit as claimed in claim 7, wherein each of the thin film transistors comprises hydrogenated amorphous silicon.

12. An integrated circuit as claimed in claim 2, wherein the matrix display is an active matrix display and each picture element circuit comprises a switching transistor, wherein each sensor comprises a phototransistor and wherein the switching transistors and phototransistors are of substantially the same design except that each of the switching transistors additionally comprises a light-blocking layer.

13. An integrated circuit as claimed in claim 12, wherein the switching transistors and phototransistors are thin film transistors.

14. An integrated circuit as claimed in claim 13, wherein the switching transistors and phototransistors comprise hydrogenated amorphous silicon.

15. An integrated circuit as claimed in claim 2, wherein the matrix display is an active matrix display and each picture element circuit comprises a switching transistor, wherein each sensor comprises a phototransistor and wherein the switching transistors and phototransistors have gate electrodes and are arranged in pairs wherein a common electrode is used for the gate electrodes of the switching transistor and phototransistor in each pair.

16. An integrated circuit as claimed in claim 2, wherein the sensors and picture element circuits are paired each pair comprising a sensor and an adjacent picture element.

17. An integrated circuit as claimed in claim 2, wherein the second multiplicity of sensors is less than the first multiplicity of picture element circuits.

18. A combined input and output device having a display mode in which it operates as a matrix display and a sensing mode in which it receives optical input, comprising:

a first multiplicity of picture element circuits arranged as a matrix display having a first plurality of rows and a second plurality of columns;

a second multiplicity of optical sensors arranged as a sensor matrix having a third plurality of rows and a fourth plurality of columns;

a first plurality of first conductive lines arranged such that, for each row of the matrix display, each of the second plurality of picture element circuits of a row of the matrix display connects to one of the first plurality of first conductive lines and, for each row of the sensor matrix, each of the fourth plurality of optical sensors of a row of the sensor matrix connects to one of the first plurality of first conductive lines; and

control circuitry for applying any one of at least three different control signals to the first plurality of first conductive lines.

19. A combined input and output device as claimed in claim 18, wherein during the display mode, the control circuitry applies a first control signal to one of the first plurality of first conductive lines and applies a second control signal to the others of the first plurality of first conductive lines.

20. A combined input and output device as claimed in claim 18, wherein during the sensing mode, the control circuitry applies a third control signal to one of the first plurality of first conductive lines and applies a fourth control signal to the others of the first plurality of first conductive lines.

21. A combined input and output device as claimed in claim 18, wherein second and fourth signals are the same.

22. A combined input and output device as claimed in claim 18, wherein the sensing mode and the display mode do not overlap in time.

23. A combined input and output device as claimed in claim 18, further comprising a second plurality of second conductive lines arranged such that, for each column of the matrix display, each of the first plurality of picture element circuits of a column of the matrix display connects to one of the second plurality of second conductive lines and, for columns of the sensor matrix, each of the third plurality of optical sensors of a column of the sensor matrix connects to one of the second plurality of second conductive lines.

25. A combined input and output device as claimed in claim 18, further comprising a third plurality of third conductive lines arranged such that, for each column of the sensor matrix, each of the third plurality of optical sensors of a column of the sensor matrix connects to one of the third plurality of third conductive lines.

26. A combined input and output device as claimed in claim 25, wherein, during the sensing mode, the control circuitry is arranged to provide an input on each of the third plurality of third conductive lines.

27. A combined input and output device as claimed in claim 18, wherein during the sensing mode an output is provided by each of the second multiplicity of optical sensors and during a display mode an input is provided to each of the first multiplicity of picture element circuits, further comprising adjustment means responsive to said outputs of the sensing mode to adjust the inputs for the display mode.

28. A combined input/output device as claimed in claim 18 wherein said first multiplicity of picture element circuits, said second multiplicity of picture element circuits, said first plurality of first conductor lines, and said control circuitry are embodied as an integrated circuit.

24. A combined input and output device as claimed in claim 24, wherein the control circuitry is arranged to provide inputs on the second plurality of conductive lines during the display mode and to receive outputs during the sensing mode.