Liquid crystal display device, black matrix substrate and color filter substrate

• US 20110043486A1
• Filed: 08/17/2010
• Published: 02/24/2011
• Est. Priority Date: 08/20/2009
• Status: Active Grant

• Current Assignee: Toppan Printing Co., Ltd. (TOPPAN Holdings, Inc.)
• Original Assignee: Toppan Printing Co., Ltd. (TOPPAN Holdings, Inc.)
• Inventors: Fukuyoshi, Kenzo, Hagiwara, Hidesato
• Granted Patent: US 8,659,724 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/13396 Spacers having different sizes
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means

Abstract

A liquid crystal display device includes a first substrate, a second substrate located opposite the first substrate via a liquid crystal, a blue display element, a green display element, a red display element, a short-wavelength optical sensor, a red optical sensor, and an infrared optical sensor formed on a liquid crystal side surface of the first substrate, and a color filter formed between the first substrate and the second substrate and includes a blue filter, a green filter, a first red filter, a short-wavelength transmission filter, a second red filter, and an infrared transmission filter corresponding to the blue display element, the green display element, the red display element, the short-wavelength optical sensor, the red optical sensor, and the infrared optical sensor, respectively.

Claims

1. A liquid crystal display device comprising:

a first substrate;

a second substrate located opposite the first substrate via a liquid crystal;

a blue display element, a green display element, a red display element, a short-wavelength optical sensor, a red optical sensor, and an infrared optical sensor formed on a liquid crystal side surface of the first substrate; and

a color filter formed between the first substrate and the second substrate and comprising a blue filter, a green filter, a first red filter, a short-wavelength transmission filter, a second red filter, and an infrared transmission filter corresponding to the blue display element, the green display element, the red display element, the short-wavelength optical sensor, the red optical sensor, and the infrared optical sensor, respectively.

2. A liquid crystal display device according to claim 1, wherein the first and second red filters have a 50% transmittance at an optical wavelength between 580 nm and 620 nm, and have a transmittance characteristic such that a transmittance is lower than the 50% transmittance when a wavelength is smaller than a wavelength corresponding to the 50% transmittance, and is higher than the 50% transmittance when the wavelength is larger than the wavelength corresponding to the 50% transmittance, and the first and second red filters are optically superimposed above the red display element and the red optical sensor, respectively, and

the infrared transmission filter has a 50% transmittance at an optical wavelength between 650 nm and 720 nm, and have a transmittance characteristic such that a transmittance is lower than the 50% transmittance when a wavelength is smaller than a value corresponding to the 50% transmittance, and is higher than the 50% transmittance when the wavelength is larger than the value corresponding to the 50% transmittance, and the infrared transmission filter is optically superimposed above the infrared optical sensor.

3. A liquid crystal display device according to claim 1, further comprising an calculating section which calculates a difference between a signal for incident light obtained by a first optical sensor and a signal for incident light obtained by a second optical sensor which is used for detecting the shortest wavelength range next to that of the first optical sensor, the first and second optical sensors being included in the plurality of optical sensors which measures the incident light via the color filter.

4. A liquid crystal display device according to claim 1, further comprising a control section which detects an object touching or approaching a display area based on signals obtained by the plurality of optical sensors formed on the first substrate and measuring the incident light via the color filter.

5. A liquid crystal display device according to claim 1, further comprising:

a first authentication section which controls the plurality of display elements formed on the first substrate to fully light up at least a part of the display area; and

a second authentication section which allows the plurality of optical sensors formed on the first substrate to measure, via the color filter, reflected light from a finger touching or approaching the at least a part of the display area, to compare the signals obtained by the plurality of optical sensors with pre-registered individual finger pattern data, and to perform individual authentication.

6. A liquid crystal display device according to claim 1, further comprising a control section which controls displayed brightness based on the signals for the incident light obtained by the plurality of optical sensors which measure the incident light via the color filter.

7. A liquid crystal display device according to claim 1, wherein the plurality of optical sensors which measures the incident light via the color filter are arranged in the display area at equal intervals, and

the device further comprises a light source formed for a back surface side of the first substrate which is not a liquid crystal side and which emits light containing at least three wavelengths for blue, green, and red.

8. A liquid crystal display device according to claim 1, further comprising a yellow optical sensor formed on a liquid crystal side surface of the first substrate, and

the color filter further comprises a yellow filter corresponding to the yellow optical sensor.

9. A liquid crystal display device according to claim 8, wherein the yellow filter has a 50% transmittance at an optical wavelength between 480 nm and 520 nm, and has a transmittance characteristic such that a transmittance is lower than the 50% transmittance when a wavelength is smaller than a wavelength corresponding to the 50% transmittance, and is higher than the 50% transmittance when the wavelength is larger than the wavelength corresponding to the 50% transmittance, and the yellow filter is optically superimposed above the yellow optical sensor.

10. A liquid crystal display device according to claim 1, wherein the short-wavelength transmission filter has a 50% transmittance at an optical wavelength between 380 nm and 450 nm, and has a transmittance characteristic such that a transmittance is lower than the 50% transmittance when a wavelength is smaller than a wavelength corresponding to the 50% transmittance, and is higher than the 50% transmittance when the wavelength is larger than the wavelength corresponding to the 50% transmittance, and the short-wavelength transmission filter is optically superimposed above the short-wavelength optical sensor.

11. A liquid crystal display device according to claim 1, wherein the short-wavelength transmission filter is a first yellow filter having a 50% transmittance at an optical wavelength between 480 nm and 520 nm, and having a transmittance characteristic such that a transmittance is lower than the 50% when a wavelength is smaller than a wavelength corresponding to the 50% transmittance, and is higher than the 50% transmittance when the wavelength is larger than the wavelength corresponding to the 50% transmittance, and the short-wavelength transmission filter is optically superimposed above the short-wavelength optical sensor,

the device further comprises a yellow display element formed on a liquid crystal side surface of the first substrate, and a second yellow filter formed between the first substrate and the second substrate and superimposed above the yellow display element.

12. A liquid crystal display device according to claim 1, wherein the infrared transmission filter has a laminating structure comprising a red layer and a blue layer.

13. A liquid crystal display device according to claim 1, wherein a black matrix having a light shield capability and comprising a material of the infrared transmission filter and an organic pigment is formed at least either on a liquid crystal side surface of the first substrate or on the second substrate.

14. A liquid crystal display device according to claim 1, further comprising a light shield area formed around an outer periphery of a display area and in which at least one of a red layer, a blue layer, and a green layer is optically superimposed.

15. A liquid crystal display device according to claim 1, further comprising a spacer which regulates a gap between the first substrate and the second substrate and is positioned between adjacent optical sensors above the first substrate when the substrates are seen in a planar view.

16. A liquid crystal display device according to claim 15, wherein the spacer is formed during the same step as that in which the short-wavelength transmission filter is formed.

17. A liquid crystal display device according to claim 1, wherein the short-wavelength transmission filter is formed of a resin material comprising an ultraviolet absorbent which absorbs the incident light at an optical wavelength shorter than 420 nm.

18. A liquid crystal display device according to claim 1, wherein the color filter is formed on a liquid crystal side surface of the first substrate.

19. A liquid crystal display device according to claim 13, wherein the black matrix further comprises a cured film of a resin material comprising an ultraviolet absorbent absorbing light at a wavelength shorter than 40 nm.

20. A black matrix substrate provided in the liquid crystal display device according to claim 1, the black matrix substrate comprising:

a black matrix having a light shield capability and located between the plurality of optical sensors formed on the first substrate adjacent to one another when the black matrix substrate which is opposite to the first substrate is placed is seen in a planar view; and

at least two types of spacers formed above the black matrix when the black matrix substrate is seen in a planar view, the spacers having different heights.

21. A color filter substrate comprising:

a color filter in which a blue filter, a green filter, a first red filter, a short-wavelength transmission filter, a second red filter, and an infrared transmission filter are arranged in a matrix arrangement; and

a light shield area formed around an outer periphery of the color filter.

22. A color filter substrate according to claim 21, wherein at least one of a red layer, a blue layer, and a green layer is optically superimposed above the light shield area.

23. A color filter substrate according to claim 21, further comprising:

a black matrix having a light shield capability and located between the plurality of optical sensors formed on a substrate adjacent to one another when the black matrix substrate placed opposite the substrate on which a blue display element, a green display element, a red display element, a short-wavelength optical sensor, a red optical sensor, and an infrared optical sensor are formed is seen in a planar view; and

at least two types of spacers formed above the black matrix when the color filter substrate is seen in a planar view, the spacers having different heights.