Liquid crystal display unit

• US 7,643,115 B2
• Filed: 10/09/2007
• Issued: 01/05/2010
• Est. Priority Date: 10/20/2006
• Status: Expired due to Fees

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Sato, Takeshi, Toyota, Yoshiaki
• Primary Examiner(s): Nguyen; Dung
• Assistant Examiner(s): DUONG, TAI V
• Application Number:
  US11/907,058
• Publication Number:
  US 20080094554A1
• Time in Patent Office: 819 Days
• Field of Search: 349/38, 349/39, 349/42, 349/113, 349/114, 349/117, 349/138, 349/139, 349/143, 349/146, 345/87, 345/88, 345/92
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer

Abstract

The present invention provides a transreflective type liquid crystal display unit, which can reduce power consumption of backlight and displays high-quality image. The liquid crystal display unit of the present invention comprises a first reflective electrode 105, which is installed on inner surface of one substrate 100 and has reflective surfaces on front and rear surfaces and is designed to have reflective lens structure with a convex portion to face to a counter electrode and has an opening 153 at the vertex of said convex portion. Further, the liquid crystal display unit has a second reflective film 104 having reflective surface on the surface facing to the first reflective electrode 105 between the first reflective electrode 105 and said one substrate 100 and under the opening 153 of the first reflective electrode 105. A light entering from the direction of said one substrate 100 is reflected by the rear surface of the first reflective electrode 105 and by the front surface of the second reflective film 104, and the light is converged to the opening 153 of the first reflective electrode 105 and is allowed to pass toward the other substrate 200.

Claims

1. A liquid crystal display unit, comprising a first substrate with a thin-film transistor provided thereon, and a second substrate with a color filter formed thereon, said first substrate and said second substrate are attached together, and a liquid crystal is sealed in a gap between said first substrate and said second substrate, wherein there are provided:

a first reflective electrode installed on inner surface of said first substrate and having reflective surfaces on front and rear surfaces, said first reflective electrode having a reflective lens structure with a convex portion to face toward said second substrate, and having an opening at the vertex of said convex portion;

a second reflective film disposed between said first reflective electrode and said first substrate and under said opening of said first reflective electrode, said second reflective film having reflective surface on a front surface facing to said first reflective electrode;

a light entering from said first substrate is reflected by the rear surface of said first reflective electrode and by the front surface of said second reflective film, said light is converged to said opening of said first reflective electrode and is allowed to pass toward said second substrate; and

wherein said first reflective electrode of a reflective lens structure with a convex portion is over an organic PAS film prepared on said first substrate and is designed in such shape as to match surface roughness of said organic PAS film.

2. A liquid crystal display unit according to claim 1, wherein and

said second reflective film is under said organic PAS film.

3. A liquid crystal display unit according to claim 2, wherein said second reflective film is on the same layer as a signal line layer of said thin-film transistor.

4. A liquid crystal display unit according to claim 1, further comprising:

a transparent pixel electrode for driving said liquid crystal via an insulator film over said first reflective electrode.

5. A liquid crystal display unit according to claim 4, wherein said first reflective electrode is a common electrode.

6. A liquid crystal display unit according to claim 5, wherein said transparent pixel electrode is connected to a source electrode or to a drain electrode of said thin-film transistor.

7. A liquid crystal display unit according to claim 4, wherein a storage capacitor is formed by said first reflective electrode and said transparent pixel electrode, and by an insulator film between said first reflective electrode and said transparent pixel electrode.

8. A liquid crystal display unit, comprising a first substrate with a thin-film transistor provided thereon, and a second substrate with a color filter formed thereon, said first substrate and said second substrate are attached together, and a liquid crystal is sealed in a gap between the said first substrate and said second substrate, wherein there are provided:

a first reflective electrode installed on inner surface of said first substrate and having reflective surfaces on front and rear surfaces, said first reflective electrode having a reflective lens structure with a convex portion to face toward said second substrate, and having an opening at the vertex of said convex portion;

a second reflective film disposed between said first reflective electrode and said first substrate and under said opening of said first reflective electrode, said second reflective film having reflective surface on the surface facing to said first reflective electrode;

said liquid crystal display unit, further comprising a transparent pixel electrode for driving said liquid crystal via an insulator film over said first reflective electrode, and a reflective electrode formed on said transparent electrode by avoiding said opening of said first reflective electrode; and

a light entering from the direction of said first substrate is reflected by rear surface of said first reflective electrode and by front surface of said second reflective film, and said light is converged to said opening of said first reflective electrode and is allowed to pass toward said second substrate via said transparent pixel electrode.

9. A liquid crystal display unit according to claim 8, wherein said first reflective electrode of a reflective lens structure with a convex portion is over an organic PAS film prepared on said first substrate and is designed in such shape as to match surface roughness of said organic PAS film;

and

said transparent pixel electrode is formed on an insulator film with surface shape similar to surface roughness of said first reflective electrode over said first reflective electrode.

10. A liquid crystal display unit according to claim 8, wherein said first reflective electrode of a reflective lens structure with a convex portion is over an organic PAS film prepared on said first substrate and is designed in such shape as to match surface roughness of said organic PAS film;

said transparent pixel electrode is formed on an insulator film with surface shape similar to surface roughness of said first reflective electrode over said first reflective electrode; and

said second reflective film is under said organic PAS film.

11. A liquid crystal display unit according to claim 10, wherein said second reflective film is on the same layer as a signal line layer of said thin-film transistor.

12. A liquid crystal display unit according to claim 8, wherein said transparent pixel electrode is for driving said liquid crystal.

13. A liquid crystal display unit according to claim 12, wherein said transparent pixel electrode is connected to a source electrode or to a drain electrode of said thin-film transistor.

14. A liquid crystal display unit according to claim 8, wherein a storage capacitor is maintained by said first reflective electrode and said transparent pixel electrode, and by an insulator film between said first reflective electrode and said transparent pixel electrode.

15. A liquid crystal display unit, comprising one a first substrate with a thin-film transistor provided thereon, and a second substrate with a color filter formed thereon, said one first substrate and said second substrate are attached together, and a liquid crystal is sealed in a gap between said first substrate and said second substrate, wherein there are provided:

a first reflective electrode installed on inner surface of said first substrate and having reflective surfaces on front and rear surfaces, said first reflective electrode having a reflective lens structure with a convex portion to face toward said eenntef second substrate, and having an opening at the vertex of said convex portion;

a second reflective film disposed between said first reflective electrode and said first substrate and under said opening of said first reflective electrode, said second reflective film having reflective surface on the surface facing to said first reflective electrode;

said liquid crystal display unit further comprising;

a retardation film formed over said first reflective electrode via an organic PAS film;

a transparent common electrode prepared on said retardation film; and

a transparent pixel electrode having an opening via an insulator film over said transparent common electrode, wherein;

a light entering from the direction of said first substrate is reflected by rear surface of said first reflective electrode and by front surface of said second reflective film and is converged to said opening of said first reflective electrode and is allowed to pass toward said second substrate.

16. A liquid crystal display unit according to claim 15, wherein said first reflective electrode of a reflective lens structure with a convex portion is over an organic PAS film prepared on said first substrate and is designed in such shape as to match surface roughness of said organic PAS film.

17. A liquid crystal display unit according to claim 15, wherein said first reflective electrode of a reflective lens structure with a convex portion is over an organic PAS film prepared on said first substrate and is designed in such shape as to match surface roughness of said organic PAS film;

and

said second reflective film is under said organic PAS film.

18. A liquid crystal display unit according to claim 17, wherein said second reflective film is on the same layer as a signal line layer of said thin-film transistor.

19. A liquid crystal display unit according to claim 15, wherein said transparent pixel electrode is connected to a source electrode or to a drain electrode of said thin-film transistor.

20. A liquid crystal display unit according to claim 15, wherein a storage capacitor is maintained by said first reflective electrode and said transparent pixel electrode, and by an insulator film between said first reflective electrode and said transparent pixel electrode.

21. A liquid crystal display unit according to claim 15, wherein said color filter and said protective film are provided on inner surface of said second substrate, and a concave portion is formed on a protective film to match the opening of said transparent pixel electrode.