Organic electroluminescence display apparatus

• US 6,369,785 B1
• Filed: 07/17/1997
• Issued: 04/09/2002
• Est. Priority Date: 08/26/1996
• Status: Expired due to Fees

• Current Assignee: Pioneer Electronics (USA) Incorporated (Pioneer Corporation)
• Original Assignee: Pioneer Electronics (USA) Incorporated (Pioneer Corporation)
• Inventors: Imai, Kunio
• Primary Examiner(s): Jankus, Almis R.
• Application Number:
  US08/895,799
• Time in Patent Office: 1,727 Days
• Field of Search: 345/76, 345/77, 345/80, 345/82
• US Class Current: 345/76
• CPC Class Codes: G06F 3/0386 for light pen
• CPC Class Codes: G09G 2300/0847 being a dynamic memory without any storage capacitor, i.e. with use of parasitic capacitances as storage elements
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2310/0256 with the purpose of reversing the voltage across a light emitting or modulating element within a pixel
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2360/148 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 3/3216 using a passive matrix
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

A light emitting display apparatus comprising organic electroluminescence elements which have photosensitive reading function is disclosed. An organic electroluminescence display apparatus comprises a plurality of organic electroluminescence elements arranged on a plane, driving means for driving said plurality of organic electroluminescence elements on the basis of an input signal to emit light from the organic electroluminescence element, light input means for irradiating the organic electroluminescence element with light, and reading means for reading out a voltage generated over the organic electroluminescence element in response to a light input from said irradiating means.

Claims

1. An organic EL display apparatus for displaying an image thereon, said apparatus comprising:

a plurality of organic EL elements arranged in a matrix form on a plane, each one of said organic EL elements including a pair of electrodes and an EL layer provided between said pair of electrodes and being able to emit light in response to an image signal supplied thereto, said EL layer generating a photoelectric voltage thereacross in response to an incident light thereon;

driving means for successively driving selected ones of said organic EL element by successively supplying drive currents across said electrodes of the selected one of said EL elements in response to an image signal supplied to said apparatus; and

signal generating means for generating an electric signal while detecting in sequence the photoelectric voltages each appearing across said electrodes of either ones of said organic EL elements.

2. An organic EL display apparatus according to claim 1, in which said driving means includes a plurality of drive-signal supply switch-circuits respectively corresponding to said EL elements each for supplying said drive current to the corresponding EL element in response to said image signal.

3. An organic EL display apparatus according to claim 2 in which said drive-signal supply switch-circuits includes common scan lines (221) each corresponding to a row of said EL elements, common data lines (224) intersecting said scan lines and each corresponding to a column of said EL elements, and an ON-OFF switch circuit (226, 227) for supplying said drive current to said EL elements (228) in response to voltages appearing across each of intersections between said common scan lines and said common data lines.

4. An organic EL display apparatus according to claim 3, in which said signal generating means includes a plurality of common read lines (222) intersecting said common scan lines and each corresponding to said row of the EL elements, a plurality of signal generating switch-circuits (225) each relaying said photoelectric voltage appearing across one of said EL elements positioned at an intersection between said common read lines and said scan lines, comparing means for comparing the relayed ones of said photoelectric voltage with at least one threshold voltage, and successively producing output voltages when said relayed ones exceeds said threshold voltage, and means for memorizing and summing said output voltages to one another so as to generate said electric signal.

5. An organic EL display apparatus according to claim 1, which further comprises:

control means for superposing said electric signal onto said image signal.

6. An organic EL display apparatus according to claim 1, which further comprises:

light irradiating means for scanning said EL elements with a light beam.