Device for and method of driving luminescent display panel

• US 7,154,492 B2
• Filed: 08/22/2003
• Issued: 12/26/2006
• Est. Priority Date: 08/29/2002
• Status: Expired due to Fees

• Current Assignee: Tohoku Pioneer Company Limited (Pioneer Corporation)
• Original Assignee: Tohoku Pioneer Company Limited (Pioneer Corporation)
• Inventors: Henmi, Koji, Yazawa, Naoki
• Primary Examiner(s): Lefkowitz, Sumati
• Assistant Examiner(s): Amadiz, Rodney
• Application Number:
  US10/645,669
• Publication Number:
  US 20040041756A1
• Time in Patent Office: 1,222 Days
• Field of Search: 345 76- 77, 345/90, 345/204, 345/207, 345/212
• US Class Current: 345/207
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• 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 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2330/028 Generation of voltages supplied to electrode drivers in a matrix display other than LCD
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/3216 using a passive matrix

Abstract

Provided is a driving device that enables compensating for the decrease in luminance characteristic due to the aging of an EL display panel. On a transparent substrate 11 made of, for example, glass, there are lamination-formed a number of luminescent elements 20. By this, a light from the luminescent element is radiated, via the transparent substrate, in a direction of its intersecting a substrate surface thereof, thereby a display image is formed. The driving device is equipped with photo-electric conversion means 23 that, when receiving part of the light from the luminescent element 20 that, by using as the interface a substrate surface of the transparent substrate 11 or a substrate surface of a light-guiding substrate 72 disposed on the transparent substrate 1 in a laminated state, is reflected within the substrate, produces an electric signal, as well as drive power setting means 25 that sets a luminescent drive power that is supplied to each of the luminescent elements. By this construction, it is possible to compensate for the decrease in luminance characteristic due to, for example, the aging of the luminescent element 20.

Claims

1. A device for driving a luminescent display panel which is adapted to obtain a display image by lamination-forming on a transparent substrate a luminescent element including an electrode and a luminescent function layer and causing a light from the luminescent element to be radiated via the transparent substrate in a direction of its intersecting the surface of the substrate at a right angle with respect thereto,

comprising photo-electric conversion means that receives the light from the luminescent element which, by using as the interface the substrate surface of the transparent substrate or a substrate surface of a light guiding substrate disposed on the transparent substrate in a laminated state, is reflected within the substrate, to thereby produce an electric signal, and drive power setting means that, according to the electric signal obtained from the photo-electric conversion means, sets a luminescent drive power that is supplied to each of the respective luminescent elements.

2. The device for driving a luminescent display panel according to claim 1, wherein the photo-electric conversion means is constructed by a light-receiving element disposed at a position that opposes a side end surface of the substrate.

3. The device for driving a luminescent display panel according to claim 1, wherein the photo-electric conversion means is constructed by a light-receiving element disposed at a position that opposes a reflecting surface that is formed at an angle that is specified with respect to the substrate surface of the substrate.

4. The device for driving a luminescent display panel according to claim 3, wherein one surface of a groove portion formed in the substrate is constructed so that it may be used as the reflecting surface.

5. The device for driving a luminescent display panel according to claim 1, wherein the photo-electric conversion means is constructed by a light-receiving element that is disposed in the way that it opposes a light-diffusing member or light-reflecting member that is located on a side end surface of the substrate or one surface thereof.

6. The device for driving a luminescent display panel according to one of claims 1 to 5, wherein the luminescent element is constructed by an organic EL element that uses an organic compound as the material of the luminescent function layer.

7. The device for driving a luminescent display panel according to claim 6, wherein the organic EL element lamination-formed on the transparent substrate is utilized as the light-receiving element.

8. A method of driving a luminescent display panel which is adapted to obtain a display image by lamination-forming on a transparent substrate a luminescent element including an electrode and a luminescent function layer and causing a light from the luminescent element to be radiated via the transparent substrate in a direction of its intersecting the surface of the substrate at a right angle with respect thereto,

comprising the step of receiving the light from the luminescent element which, by using as the interface the substrate surface of the transparent substrate or a substrate surface of a light guiding substrate disposed on the transparent substrate in a laminated state, is reflected within the substrate, to thereby produce an electric signal, and the step of executing a setting operation of setting a luminescent drive power that is supplied to each of the respective luminescent elements according to the electric signal.

9. The method of driving a luminescent display panel according to claim 8, wherein the setting operation of setting a luminescent drive power is performed by any one or any two or more of an operation of setting the magnitude of a drive current applied to the luminescent element, an operation of setting the supplying time period for supplying a drive current applied to the luminescent element, and an operation of setting the magnitude of a pre-charge voltage for performing electric pre-charge with respect to a parasitic capacitor of the luminescent element being adopted singly or adopted in combination.

10. The method of driving a luminescent display panel according to claim 8, wherein the setting operation of setting a luminescent drive power is performed at a point in time when the light-up of the luminescent display panel starts to be driven, or at a prescribed point in time during the display operation of the luminescent display panel, or through a user'"'"'s operation.

11. The method of driving a luminescent display panel according to claim 9, wherein the setting operation of setting a luminescent drive power is performed at a point in time when the light-up of the luminescent display panel starts to be driven, or at a prescribed point in time during the display operation of the luminescent display panel, or through a user'"'"'s operation.

12. The method of driving a luminescent display panel according to one of claims 8 to 11, wherein the luminescent display panel is adapted to reproduce a full color by synthesizing the color lights from the luminescent elements corresponding to respective ones of red (R), green (G), and blue (B) colors, and wherein the setting operation of setting a luminescent drive power is performed in each of the luminescent elements corresponding to respective ones of red (R), green (G), and blue (B) colors.

13. The method of driving a luminescent display panel according to one of claims 8 to 11, wherein the setting operation of setting a luminescent drive power is performed by utilizing as the parameters a photo-attenuation characteristic that is based on the positional relationship between each of the luminescent elements arrayed on the transparent substrate and a light-receiving element that produces an electric signal upon receipt of a light from the luminescent element.

14. The method of driving a luminescent display panel according to claim 12, wherein the setting operation of setting a luminescent drive power is performed by utilizing as the parameters a photo-attenuation characteristic that is based on the positional relationship between each of the luminescent elements arrayed on the transparent substrate and a light-receiving element that produces an electric signal upon receipt of a light from the luminescent element.