Liquid crystal display device

• US 6,847,426 B2
• Filed: 10/02/2002
• Issued: 01/25/2005
• Est. Priority Date: 10/02/2001
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Narutaki, Yozo, Fujimori, Kohichi
• Primary Examiner(s): Ton, Toan
• Assistant Examiner(s): DUONG, TAI V
• Application Number:
  US10/261,692
• Publication Number:
  US 20030117551A1
• Time in Patent Office: 846 Days
• Field of Search: 349/113, 349/114, 349/106, 349/122, 349/108, 349/112, 349/139, 349/143, 349/107, 349/162, 349/110
• US Class Current: 349/113
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 2203/09 transflective

Abstract

The liquid crystal display device includes a first substrate, a second substrate, a liquid crystal layer interposed between the first and second substrates, and a plurality of picture-element regions for providing display. Each of the plurality of picture-element regions has a transmission region for providing display in a transmission mode by using light incident through the first substrate, and a reflection region for providing display in a reflection mode by using light incident through the second substrate. The second substrate has a color filter layer provided in the transmission region and the reflection region. The thickness of the color filter layer in at least a part of the reflection region is smaller than the thickness of the color filter layer in the transmission region.

Claims

1. A liquid crystal display, comprising:

a first substrate;

a second substrate;

a liquid crystal layer interposed between the first and second substrates;

a plurality of picture-element regions for providing display;

wherein each of the plurality of picture-element regions comprises a transmission region for providing display in a transmission mode by using light incident through the first substrate, and a reflection region for providing display in a reflection mode by using light incident through the second substrate,

wherein the second substrate comprises a transparent substrate and a color filter layer provided in the transmission region and the reflection region;

wherein a thickness of the color filter layer in at least a part of the reflection region is smaller than a thickness of the color filter layer in the transmission region; and

wherein, at least in the reflection region of one of the picture-element regions, the second substrate comprises a plurality of spaced apart transparent dielectric layers between the transparent substrate and the color filter layer.

2. The liquid crystal display device according to claim 1, wherein, in at least part of the reflection region for each of the picture-element regions, the second substrate comprises a plurality of spaced apart transparent dielectric layers between the transparent substrate and the color filter layer.

3. The liquid crystal display device according to claim 1, wherein a thickness of the liquid crystal layer in the transmission region is larger than a thickness of the liquid crystal layer in the reflection region.

4. The liquid crystal display device according to claim 3, wherein a level of a surface of the first substrate which faces the liquid crystal layer is higher in the reflection region than in the transmission region.

5. The liquid crystal display device according to claim 1, wherein a height of the color filter layer is greater in at least the part of the reflection region where at least one of the transparent dielectric layers is formed than in the transmission region, whereby a level of a surface of the second substrate which faces the liquid crystal layer is higher in the reflection region than in the transmission region, and

a level of a surface of the first substrate which faces the liquid crystal layer is substantially the same in both the reflection region and the transmission region.

6. The liquid crystal display device according to claim 5, wherein the first substrate comprises both a transparent electrode provided in at least the transmission region and a reflecting electrode provided in at least the reflection region;

the transparent electrode and the reflecting electrode are at approximately the same level.

7. The display of claim 1, wherein a height of the color filter layer is different in at least part of the reflection region than in at least part of the transmission region, so that the color filter layer protrudes further toward the liquid crystal layer in at least part of the reflection region than in at least part of the transmission region.

8. The display of claim 1, further comprising a black matrix located between different colored areas of said color filter layer.

9. A liquid crystal display device, comprising:

a liquid crystal layer interposed between first and second substrates;

a plurality of picture-element regions for providing display;

wherein;

at least one of the picture-element regions has a transmission region for providing display in a transmission mode by using light incident through the first substrate, and a reflection region for providing display in a reflection mode by using light incident through the second substrate,

the second substrate comprises a transparent substrate and a color filter layer, and wherein a thickness of the color filter layer in at least a part of the reflection region is smaller than a thickness of the color filter layer in the transmission region,

the second substrate further comprises at least one transparent dielectric layer formed between the transparent substrate and the color filter layer in at least the part of the reflection region,

a height of the color filter layer is greater in at least the part of the reflection region where the at least one transparent dielectric layer is formed than in the transmission region, so that a level of a surface of the second substrate which faces the liquid crystal layer is higher in the reflection region than in the transmission region;

a level of a surface of the first substrate which faces the liquid crystal layer is substantially the same in both the reflection region and the transmission region; and

wherein the first substrate comprises both a transparent electrode provided in at least the transmission region and a reflecting electrode provided in at least the reflection region, and wherein the transparent electrode and the reflecting electrode of the first substrate are at approximately the same level.

10. The liquid crystal display device according to claim 9, wherein the transparent dielectric layer has a light-diffusing function.

11. The liquid crystal display device according to claim 10, wherein the transparent dielectric layer includes a transparent matrix material and a filler which is dispersed in the transparent matrix material and has a refractive index different from that of the transparent matrix material.

12. A transflective liquid crystal display, comprising:

a liquid crystal layer interposed between first and second substrates;

a plurality of picture-element regions for providing display;

wherein at least one of the picture-element regions comprises;

a transmission region for providing display in a transmission mode by using light incident through the first substrate, and a reflection region for providing display in a reflection mode by using light incident through the second substrate,

the first substrate comprising both a transparent electrode provided in at least the transmission region for use in the transmission mode, and a reflecting electrode provided in at least the reflection region for use in the reflection mode;

wherein the second substrate comprises a color filter layer provided in the transmission region and the reflection region, wherein a thickness of the color filter layer in at least a part of the reflection region is smaller than a thickness of the color filter layer in at least part of the transmission region; and

wherein no insulating layer is provided between at least some respective parts of the transparent electrode and the reflecting electrode of the first substrate so that at least said parts of the transparent electrode and reflecting electrode are in contact with one another, and wherein the transparent and reflecting electrodes are at approximately the same level even though one may at least partially overlap the other.

13. The display of claim 12, wherein a height of the color filter layer is different in at least part of the reflection region than in at least part of the transmission region, so that the color filter layer protrudes further toward the liquid crystal layer in at least part of the reflection region than in at least part of the transmission region.

14. The display of claim 12, further comprising a black matrix located between different colored areas of said color filter layer.

15. A transflective liquid crystal display, comprising:

a first substrate;

a second substrate;

a liquid crystal layer interposed between the first and second substrates;

a plurality of picture regions for providing display;

wherein at least one of the picture regions comprises a transmission region for providing display in a transmission mode by using light incident through the first substrate, and a reflection region for providing display in a reflection mode by using light incident through the second substrate,

the first substrate comprising both a transparent electrode provided in at least the transmission region for use in the transmission mode, and a reflecting electrode provided in at least the reflection region for use in the reflection mode;

wherein the second substrate comprises a color filter layer provided in the transmission region and the reflection region, wherein a thickness of the color filter layer in at least a part of the reflection region is smaller than a thickness of the color filter layer in at least part of the transmission region; and

wherein no insulating layer is provided between the transparent electrode and the reflecting electrode of the first substrate so that they are in contact with one another, with one of the reflecting and transparent electrodes at least partially overlapping the other of the reflecting and transparent electrodes.

16. The display of claim 15, wherein a height of the color filter layer is different in at least part of the reflection region than in at least part of the transmission region, so that the color filter layer protrudes further toward the liquid crystal layer in at least part of the reflection region than in at least part of the transmission region.

17. The display of claim 15, further comprising a black matrix located between different colored areas of said color filter layer.