Display panel, method of manufacturing display panel, and display apparatus

• US 20050093465A1
• Filed: 09/14/2004
• Published: 05/05/2005
• Est. Priority Date: 09/17/2003
• 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 7,071,611 B2
• Time in Patent Office: Days
• US Class Current: 315/169.3
• CPC Class Codes: H04N 9/30 using solid-state colour display devices
• CPC Class Codes: H10K 50/80 Constructional details
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 59/10 OLED displays
• CPC Class Codes: H10K 59/17 Passive-matrix OLED displays
• CPC Class Codes: H10K 59/173 comprising banks or shadow masks
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/805 Electrodes

Abstract

Exemplary embodiments of the present invention provide a display panel or the like in which it is easy to enlarge a size of the display panel. A display panel according to exemplary embodiments includes a first transparent electrode layer and a second transparent electrode layer which are optically transparent, a conductivity-variable layer which is provided on the first transparent electrode layer, and an electroluminescent layer which is provided between the conductivity-variable layer and the second transparent electrode layer, and which emits light by applying a voltage thereto.

Claims

1. A display panel, comprising:

a first optically transparent electrode layer;

a second optically transparent electrode layer;

a conductivity-variable layer provided on the first optically transparent electrode layer; and

an electroluminescent layer provided between the conductivity-variable layer and the second optically transparent electrode layer, which emits light by applying a voltage thereto;

a predetermined voltage being applied between the first optically transparent electrode layer and the second optically transparent electrode layer, and the conductivity-variable layer having its electrical conductivity changed in accordance with a light quantity of control light transmitted through the first optically transparent electrode layer; and

the electroluminescent layer emitting the light so that the voltage in the predetermined voltage as corresponds to the conductivity of the conductivity-variable layer, is applied thereto when the conductivity of the conductivity-variable layer has been changed in accordance with the light quantity of the control light transmitted through the first optically transparent electrode layer.

2. The display panel as defined in claim 1, the electroluminescent layer having a structure in which the electroluminescent layer is divided into a plurality of regions corresponding to pixels.

3. The display panel as defined in claim 2, further comprising:

a light shield portion provided near a surface of the first optically transparent electrode layer where the control light enters, and which is formed with openings in correspondence with the pixels;

each of the openings being arranged at a position through which the control light is passed, thereby to be entered into a position of the first optically transparent electrode layer as corresponds to a predetermined one of the pixels; and

the electroluminescent layer emitting the light on the pixel basis so that the control light passed through the opening is entered into only a part of the first transparent electrode layer corresponding to the predetermined pixel.

4. The display panel as defined in claim 2, the electroluminescent layer having a structure that is divided into a plurality of regions corresponding to the pixels, by a plurality of partition members provided on the conductivity-variable layer.

5. The display panel as defined in claim 2,

the electroluminescent layer including a reflection electrode provided in correspondence with the pixels, on its surface on a side which lies in touch with the conductivity-variable layer;

and

the reflection electrode having a region which is larger than a region of the electroluminescent layer that corresponds to each of the pixels.

6. The display panel as defined in claim 2, the conductivity-variable layer having a structure that is divided into a plurality of regions corresponding to the pixels.

7. The display panel as defined in claim 2,

the plurality of regions of the electroluminescent layer being provided in correspondence with pixels for first color light, pixels for second color light, and pixels for third color light;

each pixel aggregate being constructed of one of the pixels for the first color light, one of the pixels for the second color light, and one of the pixels for the third color light; and

a plurality of such pixel aggregates being provided at substantially equal intervals in two predetermined directions being substantially orthogonal to each other.

10. A display apparatus, comprising:

a display panel;

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

an optical system for control light, which supplies control light to the display panel;

the display panel being the display panel as defined in claim 1, and the power source applies the voltage between the first optically transparent electrode layer and the second optically transparent electrode layer of the display panel; and

the optical system for the control light entering the control light into the first optically transparent electrode layer of the display panel.

11. The display apparatus as defined in claim 10, the optical system for the control light passing the control light through each opening, thereby to enter the control light into only the position of the first transparent electrode layer corresponding to a predetermined pixel.

12. The display apparatus as defined in claim 10:

the optical system for the control light including a plurality of light source units for the control lights;

each of the light source units for the control lights consisting of a first light source portion for the control light that supplies the first control light to a part of the first optically transparent electrode layer corresponding to the pixel for the first color light, a second light source portion for the control light that supplies the second control light to a part of the first transparent electrode layer corresponding to the pixel for the second color light, and a third light source portion for the control light that supplies the third control light to a part of the first transparent electrode layer corresponding to the pixel for the third color light; and

the plurality of light source units for the control lights supplying the first control light, the second control light and the third control light to different regions of the display panel, respectively.

13. The display apparatus as defined in claim 10, comprising:

a frame in which, at least the optical system for the control lights is accommodated;

the display panel being mounted on the frame.

14. The display panel as defined in claim 1, light from another image display apparatus being employed as the control light.

8. A method of manufacturing a display panel, comprising:

forming a first transparent electrode layer on a substrate;

forming a conductivity-variable layer on the first transparent electrode layer formed at the first-transparent-electrode-layer formation;

forming partition members in a predetermined pattern on the conductivity-variable layer formed at the conductivity-variable-layer formation;

forming an electroluminescent layer among the partition members formed at the partition-member formation;

forming a second transparent electrode layer on the partition members formed at the partition-member formation, and the electroluminescent layer formed at the electroluminescent-layer formation; and

forming a protective layer on the second transparent electrode layer formed at the second-transparent-electrode-layer formation.

9. A method of manufacturing a display panel, comprising:

forming a first layered structure which has a first substrate, a first transparent electrode layer and a conductivity-variable layer, the first-layered-structure formation including;

forming the first transparent electrode layer on the first substrate; and

forming the conductivity-variable layer on the first transparent electrode layer formed at the first-transparent-electrode-layer formation;

forming a second layered structure which has a second substrate, a second transparent electrode layer, partition members and an electroluminescent layer, the second-layered-structure formation including;

forming the second transparent electrode layer on the second substrate;

forming the partition members in a predetermined pattern on the second transparent electrode layer formed at the second-transparent-electrode-layer formation; and

forming the electroluminescent layer on regions of the second transparent electrode layer which are surrounded with the partition members formed at the partition-member formation; and

sticking to each other the conductivity-variable layer formed at the first-layered-structure formation, and the electroluminescent layer formed at the second-layered-structure formation, thereby to unite the first layered structure formed at the first-layered-structure formation, and the second layered structure formed at the second-layered-structure formation.