Display panel and display device

• US 20050242710A1
• Filed: 04/26/2005
• Published: 11/03/2005
• Est. Priority Date: 04/30/2004
• Status: Active Grant

• Current Assignee: 138 East LCD Advancements Limited (Vector Capital Corporation)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Yonekubo, Masatoshi, Yamazaki, Tetsuro, Takeda, Takashi
• Granted Patent: US 7,514,865 B2
• Time in Patent Office: Days
• US Class Current: 313/500
• CPC Class Codes: G09G 3/02 by tracing or scanning a light beam on a screen
• CPC Class Codes: H10K 2102/3031 Two-side emission, e.g. transparent OLEDs [TOLED]
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/80 Constructional details
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/50 OLEDs integrated with light modulating elements, e.g. with electrochromic elements, photochromic elements or liquid crystal elements
• CPC Class Codes: H10K 59/60 OLEDs integrated with inorganic light-sensitive elements, e.g. with inorganic solar cells or inorganic photodiodes

Abstract

Exemplary embodiments of the invention provide a display panel, etc. which can be controlled by optical addressing, and which are simple in construction and can reduce costs. According to exemplary embodiments, a display device includes a first transparent electrode layer and a second transparent electrode layer which are optically transparent, a variable conductivity layer which is disposed on the first transparent electrode layer and whose electrical conductivity is changed in accordance with the light quantity of control light L transmitted through the first transparent electrode layer, and a functional layer having at least a light emission layer, which is stacked on the variable conductivity layer and which is interposed between the variable conductivity layer and the second transparent electrode layer. A predetermined voltage is applied between the first transparent electrode layer and the second transparent electrode layer, and the light emission layer emits light in accordance with the light quantity of the control light L.

Claims

1. A display panel, comprising:

a first optically transparent electrode layer;

a second optically transparent electrode layer;

a variable conductivity layer disposed on the first optically transparent electrode layer, and having an electrical conductivity that is changed in accordance with a light quantity of control light transmitted through the first transparent electrode layer; and

a functional layer having, at least, a light emission layer, which is stacked on the variable conductivity layer, and which is interposed between the variable conductivity layer and the second transparent electrode layer; and

a predetermined voltage applied between the first transparent electrode layer and the second transparent electrode layer;

the light emission layer emitting light in accordance with the light quantity of the control light.

2. The display panel according to claim 1,

the function layer including a hole transport layer which is stacked and disposed on the variable conductivity layer, the light emission layer which is disposed on the hole transport layer, and an electron transport layer which is interposed between the light emission layer and the second transparent electrode layer;

the hole transport layer transporting holes to the light emission layer in such a way that, of the predetermined voltage, a voltage corresponding to the conductivity of the variable conductivity layer is applied to the hole transport layer;

the electron transport layer transporting electrons to the light emission layer in such a way that, of the predetermined voltage, a voltage corresponding to the conductivity of the variable conductivity layer is applied to the electron transport layer; and

the light emission layer emitting the light in accordance with the light quantity of the control light on a basis of the holes from the hole transport layer and the electrons from the electron transport layer.

3. The display panel according to claim 1, the light emission layer including a light emission layer for first color light, which is disposed in correspondence with a pixel for the first color light as supplies the first color light, a light emission layer for second color light, which is disposed in correspondence with a pixel for the second color light as supplies the second color light, and a light emission layer for third color light, which is disposed in correspondence with a pixel for the third color light as supplies the third color light.

4. The display panel according to claim 1, light from another image display device being employed as the control light.

5. A display device, comprising:

the display panel according to claim 1;

a power source which applies the predetermined voltage to the display panel; and

an optical system for the control light as supplies the control light to the display panel.