Display panel associated with light collecting plate and position adjusting method using microlenses for the display panel

• US 6,204,895 B1
• Filed: 09/30/1998
• Issued: 03/20/2001
• Est. Priority Date: 09/30/1997
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nakamura, Hiroki, Watanabe, Yoshihiro, Nakamura, Takafumi
• Primary Examiner(s): Parker, Kenneth
• Assistant Examiner(s): Qi, Mike
• Application Number:
  US09/163,204
• Time in Patent Office: 902 Days
• Field of Search: 349/5, 349/7, 349/8, 349/95, 349/187
• US Class Current: 349/5
• CPC Class Codes: G02F 1/133354 Arrangements for aligning or assembling substrates
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses

Abstract

A display panel is to be fixed to a light collecting plate having a plurality of lenses and includes a matrix array of pixel electrodes opposed to the lenses of the light collecting plate, a plurality of electrode wiring lines formed along rows and columns of the pixel electrodes, and a driver circuit formed outside a display area corresponding to the matrix array of the pixel electrodes, for driving the pixel electrodes via the electrode wirings. Particularly, in the display panel, a plurality of alignment marks for positional adjustment of aligning the focal spots of the lenses with the pixel electrodes are arranged to be opposed to the lenses and separated from the display area by a distance corresponding to an integer number of times of a pitch of the pixel electrodes in at least one of row and column directions of the pixel electrodes.

Claims

1. A display panel to be fixed to a light collecting plate having a plurality of lenses, comprising:

a matrix array of pixel electrodes opposed to the lenses of the light collecting plate;

a plurality of electrode wiring lines formed along rows and columns of the pixel electrodes;

a driver circuit formed outside a display area corresponding to the matrix array of the pixel electrodes, for driving the pixel electrodes via the electrode wirings; and

a plurality of alignment marks for positional adjustment of aligning the focal spots of the lenses with the pixel electrodes;

wherein the alignment marks are arranged to be opposed to the lenses and separated from the display area by a distance corresponding to an integer number of times of a pitch of the pixel electrodes in at least one of row and column directions of the pixel electrodes.

2. A display panel according to claim 1, wherein the alignment marks are placed on both sides of the display area along at least one of the central row and central column of the pixel electrodes.

3. A display panel according to claim 1, wherein each of the alignment marks is formed in a dummy pixel area located between the driver circuit and the display area.

4. A display panel according to claim 3, wherein each of the alignment marks is assigned to one of dummy pixel electrodes for three primary colors arranged in the dummy pixel area.

5. A display panel according to claim 3, wherein each of the alignment marks is composed of three mark patterns which are formed at positions of the dummy pixel electrodes for three primary colors arranged in the dummy pixel area, and one of the three mark patterns is different in shape from the other two.

6. A display panel according to claim 1, wherein each of the alignment marks is made of the same material as the electrode wiring lines.

7. A display panel according to claim 3, wherein the dummy pixel area is covered with a light-shielding member except for the dummy pixel electrodes.

8. A display panel according to claim 3, further comprising a dummy driver circuit for driving dummy pixel electrodes arranged in the dummy pixel area.

9. A display panel according to claim 8, wherein the dummy driver circuit is arranged to apply a black display voltage to the dummy pixel electrodes.

10. A display panel according to claim 9, wherein the pixel wiring lines include scanning lines formed along rows of the pixel electrodes and the dummy pixel electrodes and signal lines formed along columns of the pixel electrodes and the dummy pixel electrodes, the pixel electrodes and the dummy pixel electrodes are connected to a plurality of switching elements each of which outputs a voltage on a corresponding signal line in response to a selection signal from a corresponding scanning line, and the dummy driver circuit is connected to ones of the signal lines that correspond to dummy pixel electrodes associated with the alignment marks to apply the black display voltage to these dummy electrodes.

11. A display panel according to claim 10, wherein the dummy driver circuit includes a control unit for applying the black display voltage to the dummy pixel electrodes associated with the alignment marks during a blanking period of a video signal applied for the pixel electrodes.

12. A display panel according to claim 1, further comprising:

an array substrate having the pixel electrodes, the electrode wiring lines, and the driver circuit;

a counter substrate having a counter electrode opposed to the pixel electrodes; and

a liquid crystal layer held between the array substrate and the counter substrate;

wherein the alignment marks are formed on one of the array substrate and the counter substrate which is located on a side opposite to the light collecting plate to emit light incident from the light collecting plate.

17. A display panel according to claim 1, wherein each of the alignment marks is made of a vernier pattern.

18. A display panel according to claim 1, wherein one of the alignment marks is disposed in the driver circuit and opposed to the light collecting plate.

19. A display panel according to claim 1, wherein the alignment marks are disposed on both sides of the display area in an orthogonal direction of the light collecting plate.

13. A position adjusting method for a display panel to be fixed to a light collecting plate having a plurality of lenses, comprising steps of:

preparing the display panel which comprises an array substrate including a matrix array of pixel electrodes opposed to the lenses of the light collecting plate, a plurality of electrode wiring lines formed along rows and columns of the pixel electrodes, and a driver circuit formed outside a display area corresponding to the matrix array of the pixel electrodes, for driving the pixel electrodes via the electrode wirings;

a counter substrate which includes a counter electrode opposed to the matrix array of the pixel electrodes;

a liquid crystal layer held between the array substrate and the counter substrate; and

a plurality of alignment marks which is formed on one of the array substrate and the counter substrate from which light applied via the light collecting plate is output, arranged to be opposed to the lenses, and separated from the display area by a distance corresponding to an integer number of times of a pitch of the pixel electrodes in at least one of row and column directions of the pixel electrodes; and

adjusting a positional relationship between the focal spots of the lenses and the alignment marks such that the focal spots of the lenses are aligned with the pixel electrodes.

14. A position adjusting method according to claim 13, wherein the adjustment is made by directing laser light from a laser light source onto the array substrate through the light collecting plate, determining a deviation of a spot of laser light focused by one of the microlenses of the light collecting plate from the center of an alignment mark assigned to the one microlens, and collecting the position of the light collecting plate to eliminate the deviation.

15. A position adjusting method according to claim 14, the determination of the deviation is made through the use of a monitor that displays, together with a scale, the spot of laser light and the alignment mark which are observed on the opposite side of the array substrate from the laser light source.

16. A position adjusting method according to claim 15, wherein each of the alignment marks is composed of three mark patterns which are formed at positions of the dummy pixel electrodes for three primary colors arranged in the dummy pixel area, and one of the three mark patterns is different in shape from the other two.