Penlight and touch screen data input system and method for flat panel displays

• US 7,166,966 B2
• Filed: 02/08/2005
• Issued: 01/23/2007
• Est. Priority Date: 02/24/2004
• Status: Expired due to Fees

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Nuelight Corporation
• Inventors: Reddy, Damoder, Naugler, W. Edward Jr.
• Primary Examiner(s): Dinh; Trinh Vo
• Application Number:
  US11/054,350
• Publication Number:
  US 20050200293A1
• Time in Patent Office: 714 Days
• Field of Search: 315/149, 315/150, 315/151, 315/169.2, 345/82
• US Class Current: 315/149
• CPC Class Codes: G06F 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• CPC Class Codes: G06F 3/03542 Light pens for emitting or receiving light
• CPC Class Codes: G06F 3/0386 for light pen
• 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 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2310/066 Waveforms comprising a gently increasing or decreasing portion, e.g. ramp
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/0295 by monitoring each display pixel
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2360/142 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 2360/147 the originated light output being determined for each pixel
• CPC Class Codes: G09G 2360/148 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3275 Details of drivers for data electrodes
• CPC Class Codes: G09G 3/3291 : in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
• CPC Class Codes: H01L 27/1446 : in a repetitive configuration
• CPC Class Codes: H10K 2102/3026 : Top emission
• CPC Class Codes: H10K 59/126 : Shielding, e.g. light-blocking means over the TFTs
• CPC Class Codes: H10K 59/13 : comprising photosensors that control luminance
• CPC Class Codes: H10K 59/40 : OLEDs integrated with touch screens
• CPC Class Codes: H10K 59/60 : OLEDs integrated with inorganic light-sensitive elements, e.g. with inorganic solar cells or inorganic photodiodes
• CPC Class Codes: H10K 65/00 : Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element and at least one organic radiation-sensitive element, e.g. organic opto-couplers organic image sensors integrated with organic light-emitting devices H10K39/34; OLED displays integrated with photosensors H10K59/13

Abstract

System, device, and method for receiving or sensing touch or light input to an emissive display such as to a OLED display using the same or different sensors as are used to sense and maintain a pixel luminance. Penlight and touch screen data input system and method for display. A sidelight illuminated display and touch panel input device. Method and device for reading display pixel emission and ambient luminance levels. Emissive display having sensing for luminance stabilization and user light or touch screen input. Method and device for emissive display using shielded or partially shielded sensors. Emissive pixel display device characterized in that photon sensors are disposed within pixels and operated to sense photons emitted by emitter within pixel and ambient photons emitted by sources outside pixel, sensed internally emitted photons being for luminance feedback control and sensed ambient photons being used to detect external light source or sources.

Claims

1. An emissive pixel device having an integrated luminance and input sensor, the pixel device comprising:

a light emitting device;

a pixel emitter drive circuit generating a current to drive the light emitting device to a predetermined luminance corresponding to an image voltage and applying the drive current to the light emitting device during a frame time;

at least one photo sensor that exhibits a change in electrical characteristic in response to a change in incident photon flux disposed near the light emitting device to;

(i) intercept a measurable photon flux when the light emitting device is in an emitting state, and (ii) to detect a measurable photon flux from a source outside the pixel when the light emitting device is not in an emitting state;

at lease one of a voltage, current, and charge reading circuit for measuring;

(i) a first voltage across, a first current from, or a first charge generated by the photo sensor device at the end of a first portion of a non-emitting time period during a non-light emitting state, and wherein the measured first voltage, first current, or first charge being in indication of a measured luminance emitted from a source outside the pixel during the first portion of the time period; and

(ii) a second voltage across, a second current from, or a second charge generated by the photo sensor device at the end of a second portion of an emitting time period during the light emitting state, and wherein the measured second voltage, second current, or second charge being an indication of a measured luminance emitted from the pixel during a second portion of the time period.

2. The emissive pixel device as in claim 1, further comprising:

at least one charge storage device coupled with the sensor for accumulating or releasing charges and exhibiting a capacitance charge and voltage proportional to the charge at a time; and

a control circuit controlling the charging and/or discharging of at least one charge storage device in response to changes and/or discharging of the at least one charge storage device in response to changes in the electrical characteristics of the at least one photo sensor device during at least one of the emitting state and non-emitting state time periods.

3. The emissive pixel device as in claim 2, wherein the control circuit controls the charging and/or discharging of the at least one charge storage device in response to changes in the electrical characteristics of the at least one photo sensor device during the emitting state and non-emitting state time periods.

4. The emissive pixel device in claim 3, wherein the photo sensor device comprises a photo-responsive sensor.

5. The emissive pixel device as in claim 4, wherein the photo sensor device further comprises the at least one charge storage device.

6. The emissive pixel device as in claim 5, wherein the first voltage across, the first current from, or the first charge generated by the photo sensor device are measured based on a charge state of the at least one charge storage device.

7. The emissive pixel device as in claim 6, wherein the second voltage across, the second current from, or the second charge generated by the photo sensor device are measured based on a charge state of the at least one charge storage device.

8. The emissive pixel device as in claim 7, wherein the first emitting time period is a portion of the display frame time, and the second non-emitting time period is selected from the set of second time periods consisting of a portion of at least one of a row address time, a portion of a second frame time dedicated to measuring luminance incident upon the pixel that is a different frame time from the first time period, a portion of a time period for a display vertical retrace time, portion of a time period for a display horizontal retrace time.

9. The emissive pixel device as in claim 8, wherein the at least one charge storage device comprises separate first and second charge storage devices and wherein the first charge storage device provides an indication of the measured luminance emitted from the pixel during a portion of the first time period, and the second charge storage device provides an indication of the measured luminance incident upon the pixel during the second time period.

10. The emissive pixel device as in claim 9, wherein the voltage across, the current from, and the charge on the at least one charge storage device represents an integrated photon flux during the portion of the frame time over which the control circuit permitted charging or discharging or the charge storage device.

11. An The emissive pixel device as in claim 10, wherein the voltage, current, or charge reading circuit further comprising a comparator circuit that receives the voltage, current, or charge reading and a reference value corresponding to a target pixel luminance and generates a difference signal representing the difference between the target pixel luminance and the measured luminance.

12. The emissive pixel device as in claim 11, wherein the read circuit is configured as a charge amp/transimpedance amplifier having a charge amplifier circuit.

13. The emissive pixel device as in claim 8, wherein the voltage across, the current from, and the charge on the at least one charge storage device represents an integrated photon flux during the portion of the frame time over which the control circuit permitted charging or discharging or the charge storage device.

14. The emissive pixel device as in claim 8, wherein the light emitting device comprises a light emitting device selected from the set consisting of an organic light emitting diode (OLED) device, an electroluminescent device, a plasma emission device, and a controllable photon emissive device.

15. The emissive pixel device as in claim 8, further comprising comparison means for comparing the indication of the measured luminance incident upon the pixel during the second time period for a plurality of pixels in the display to identify a location where the measured luminance in an area is a predetermined magnitude greater than or a predetermined magnitude less than a measured luminance for adjacent or surrounding pixels.

16. The emissive pixel device as in claim 8, wherein pixels include a light shield that attenuates at least a portion of photons from ambient light incident on the display from an external light source.

17. The emissive pixel device as in claim 16, wherein the light shield includes an aperture or hole to permit at least a portion of photons from ambient light incident on the display from an external light source to enter the pixel.

18. A method of operating an emissive pixel device having an integrated luminance and input sensor, the method comprising:

generating a current to drive a light emitting device in each pixel to a predetermined luminance corresponding to an image voltage and applying the drive current to the light emitting device during the frame time;

providing a least one photo sensor that exhibits a change in electrical characteristic in response to a change in incident photon flux near the light emitting device in each pixel to;

(i) intercept a measurable photon flux when the light emitting device is in an emitting state, and (ii) to detect a measurable photon flux from a source outside the pixel when the light emitting device is not in an emitting state;

reading at least one of a voltage, current, and charge measurement representing;

(i) a first voltage across, a first current from, or a first charge generated by the photo sensor device at the end of a first portion of a non-emitting time period during the non-light emitting state, and wherein the measured first voltage, first current, or first charge being an indication of a measured luminance emitted from a source outside the pixel during the first portion of the time period; and

(ii) a second voltage across, a second current from, or a second charge generated by the photo sensor device at the end of a second portion of an emitting time period during the light emitting state, and wherein the measured second voltage, second current, or second charge being an indication of a measured luminance emitted from the pixel during a second portion of the time period.