CN100504537C

CN100504537C - Color filter and liquid crystal display including the same

Info

Publication number: CN100504537C
Application number: CNB2004101012905A
Authority: CN
Inventors: 丁岱良; 温志坚; 郑其铭; 郭光埌; 庄享儒; 蔡佳怡
Original assignee: Toppoly Optoelectronics Corp
Current assignee: TPO Displays Corp
Priority date: 2004-12-15
Filing date: 2004-12-15
Publication date: 2009-06-24
Anticipated expiration: 2024-12-15
Also published as: CN1790128A

Abstract

The present invention provides a color filter, which includes a plurality of pixel areas, each pixel area includes three sub-pixel areas, each sub-pixel area is divided into a transmission area and a reflection area. The color filter includes three color photoresists of different colors on the three sub-pixel areas of each pixel area, wherein the color purity of the color photoresist at the reflection area of one or two sub-pixel areas is lower than the color purity of the color photoresist at the transmission area.

Description

Colored filter and the LCD that comprises this colored filter

Technical field

The invention relates to a kind of colored filter, be particularly to a kind of colored filter that can be applicable to semitransparent and half-reflective liquid crystal display, the color saturation of echo area and penetrating region is reached unanimity.

Background technology

LCD (LCD; Liquid crystal display) can be divided into three kinds, penetration (transmissive) LCD, reflective (reflective) LCD and semi-penetration, semi-reflective (transflective) LCD.Penetration LCD uses (back light) backlight to make light source, but through after polaroid and the liquid crystal panel, and 10% the light of only having an appointment is utilized, therefore, if the brightness that will improve penetration LCD needs increase power consumption backlight.Reflective LCD is to use surround lighting to make light source, therefore comparatively power saving.Yet reflective LCD only can use by day or under the situation that has ambient light to exist in the office, but can't use under night or low-light.

Therefore, semi-penetration, semi-reflective LCD promptly in response to and give birth to.Fig. 1 shows the diagrammatic cross-section of existing semi-penetration, semi-reflective LCD, and it comprises upper substrate 160, infrabasal plate 150, liquid crystal layer 180 is folded between the upper and lower substrate, and the position under infrabasal plate 150 backlight 170.Common electrode 162 is folded between upper substrate 160 and the liquid crystal layer 180, and penetrating region electrode 164 is positioned on the penetrating region t of infrabasal plate 150.Echo area electrode 152 is positioned on the echo area r of infrabasal plate 150.Colored filter 168 is between upper substrate 160 and common electrode 162.Under the pattern of penetrating, 170 light that sent 174 backlight are through infrabasal plate 150, penetrating region electrode 164, colored filter 168 and upper substrate 160.Under reflective-mode, surround lighting 172 incides on the echo area electrode 152 via upper substrate 160 and colored filter 168, and colored filter 168 and upper substrate 160 are passed through in region electrode 152 reflections that are reflected once more.

As mentioned above, at penetrating region t, 170 light that sent 174 backlight only penetrate colored filter 168 once, but at echo area r, and surround lighting 172 but penetrates colored filter 168 twice.Therefore, can cause of the color saturation condition with higher generation of the color saturation of echo area than penetrating region.

For addressing the above problem, people such as Tomohisa Matsushita are at U.S.Patent No.6, disclose in 501,521 the chromatic photoresist of position on reflecting plate dug a hole or finedraw, insert transparent photoresistance again, can change the color saturation of echo area.For example, Fig. 2 shows U.S.Patent No.6, the planimetric map of the color photoresistance of a pixel region of semitransparent and half-reflective liquid crystal display in 501,521.This pixel is divided into R (red), G (green), and three pixel regions of B (indigo plant), each time pixel region is divided into echo area and penetrating region again.The echo area is denoted as R (r) respectively, G (r), and B (r), penetrating region are denoted as R (t) respectively, G (t), B (t), chromatic photoresist is denoted as 210R, 220G, 230B respectively.Its practice is, red photoresistance 210R in the echo area R (r) of R pixel region is removed a part, insert transparent photoresistance 210W again, green photoresistance 220G in the echo area G (r) of G pixel region is removed a part, insert transparent photoresistance 220W again, and the blue photoresistance 230B in the echo area B (r) of B pixel region is removed a part, insert transparent photoresistance 230W again.By the size of adjusting excavation region, the colour mixture of transparent photoresistance and chromatic photoresist in the control echo area is minimized the color saturation of echo area, makes the color saturation of echo area and penetrating region reach unanimity.

Though said method can reduce the color saturation of echo area, yet, see also Fig. 3, if use the higher chromatic photoresist of excitation, its penetrance lower (Y＜15.0), then the color saturation of echo area (NTSC ratio) has the limit, can not increase because of the ratio of digging a hole, the highlyest also only have an appointment 35%, still have very big gap with the color saturation of penetrating region.

In addition, also have at R, G uses the lower chromatic photoresist of excitation in the echo area of B three looks, in the hope of reducing the color saturation of echo area, makes the color saturation of echo area and penetrating region reach unanimity.Yet this practice needs to use six kinds of chromatic photoresists altogether, promptly needs six road light shield processing procedures.Each chromatic photoresist all needs through coating photoresistance, exposure, development, hard step such as roasting, and step is very complicated, so expense is high.

Summary of the invention

In view of this, purpose of the present invention provides a kind of colored filter for addressing the above problem, and can make the color saturation of echo area and penetrating region close, and processing procedure is simple.

The present invention also provides the semitransparent and half-reflective liquid crystal display that comprises above-mentioned colored filter.

For reaching purpose of the present invention, colored filter of the present invention comprises a plurality of pixel regions, and each pixel region comprises pixel region three times, and each time pixel region is divided into penetrating region and echo area.Colored filter comprises the chromatic photoresist of three different colours on three pixel regions of each pixel region, be respectively R (red), G (green) and B (indigo plant), the invention is characterized in that the excitation ratio of the chromatic photoresist at the place, echo area of one of them time pixel region is low in the excitation of the chromatic photoresist at penetrating region place.

Description of drawings

Fig. 1 shows the diagrammatic cross-section of traditional semi-penetrated semi-reflected liquid crystal display.

Fig. 2 shows U.S.Patent No.6, the planimetric map of the color photoresistance of a pixel region of semitransparent and half-reflective liquid crystal display in 501,521.

Fig. 3 shows U.S.Patent No.6, the color saturation of colored filter and the graph of a relation of Y in 501,521.

Fig. 4 shows the planimetric map according to the optical filter of a pixel cell of the present invention's first specific embodiment.

Fig. 5 shows the diagrammatic cross-section of looking along the 5-5 line of Fig. 4.

Fig. 6 shows the planimetric map according to the optical filter of a pixel cell of the present invention's second specific embodiment.

Fig. 7 shows the diagrammatic cross-section of looking along the 7-7 line of Fig. 6.

Fig. 8 shows the color saturation of the colored filter that the resistance of four coloured light, multicolored photoresistance and six coloured light hinder and the graph of a relation of Y.

Symbol description:

150～infrabasal plate,

152～reflecting electrode,

154～light openings,

160～upper substrate,

162～common electrode,

164～penetrating region electrode,

168～optical filter,

170～backlight,

172～surround lighting,

174～the light that sends backlight,

180～liquid crystal layer,

T～penetrating region,

R～echo area,

R～redness time pixel region,

G～green time pixel region,

B～blue sub-pixels district,

R (r)～red reflex district,

G (r)～green echo area,

B (r)～blue echo area,

R (t)～red penetrating region,

G (t)～green penetrating region,

B (t)～blue penetrating region,

210R～red photoresistance,

220G～green photoresistance,

230B～blue photoresistance,

210W, 220W, 230W～transparent photoresistance,

R～redness time pixel region,

G～green time pixel region,

B～blue sub-pixels district,

R (r)～red reflex district,

G (r)～green echo area,

B (r)～blue echo area,

R (t)～red penetrating region,

G (t)～green penetrating region,

B (t)～blue penetrating region,

40R～red photoresistance,

40B～blue photoresistance,

The green photoresistance of 41G～first,

The green photoresistance of 42G～second,

The red photoresistance of 41R～first,

The red photoresistance of 42R～second,

10～the first substrates,

21～echo area electrode,

22～penetrating region electrode,

30～the second substrates,

50～liquid crystal layer.

Embodiment

The present invention is the chromatic photoresist that uses different excitations at the echo area of one or two time pixel region and penetrating region place, and the chromatic photoresist at place, echo area has lower excitation, and the chromatic photoresist at penetrating region place has higher excitation.So, can reduce the color saturation in overall reflective district, make the color saturation of echo area and penetrating region reach unanimity.

Fig. 4 shows the planimetric map according to the colored filter of a pixel cell of the present invention's first specific embodiment, shows that green time pixel region uses the situation of the green photoresistance of different excitations.This pixel cell is divided into pixel region: R, G, B three times.Echo area and penetrating region with respect to multiple substrate (Fig. 5 demonstrates the multiple substrate 10 of part), each time pixel region all is divided into echo area and penetrating region, thereby be divided into red reflex district R (r), green echo area G (r), blue echo area B (r) and red penetrating region R (t), green penetrating region G (t), blue penetrating region (t).Fig. 6 is presented in time pixel region, and the echo area is on the next door of penetrating region, but the present invention is not as limit.The echo area of inferior pixel region also can be positioned at the periphery of penetrating region.

See also Fig. 4, use a kind of red photoresistance 40R in R the pixel region, use a kind of blue photoresistance 40B in B the pixel region, as for then using two kinds of green photoresistances in G the pixel region: the first green photoresistance 41G is positioned at green echo area G (r), and one second green photoresistance 42G then is positioned at green penetrating region G (t).The excitation of the first green photoresistance 41G is low than the excitation of the second green photoresistance 42G.

The diagrammatic cross-section of Fig. 5 for looking along the 5-5 line of Fig. 4, G pixel region of demonstration semitransparent and half-reflective liquid crystal display.See also Fig. 5, this semi-penetration semi-reflective LCD comprises first substrate, 10, the second substrates 30, and the liquid crystal layer 50 between first substrate 10 and second substrate 30.G time pixel region is divided into the first green photoresistance 41G and the second green photoresistance 42G, the then corresponding penetrating region electrode 22 of corresponding echo area electrode 21, the second green photoresistance 42G of the first green photoresistance 41G.Because the excitation at the first green photoresistance 41G of echo area G (r) is low at the second green photoresistance 42G of penetrating region G (t), thus the color saturation in overall reflective district can be reduced, and make the color saturation of overall reflective district and whole penetrating region reach unanimity.Semi-penetration semi-reflective LCD of the present invention, its chromatic photoresist can be made on first substrate 10 or second substrate 30.In brief, the colored filter of above-mentioned first specific embodiment comprises: a kind of red photoresistance 40R; A kind of blue photoresistance 40B; And two kinds of green photoresistance 41G and 42G, and the excitation of the green photoresistance 41G at place, echo area is lower than the excitation of the green photoresistance 42G at penetrating region place.

Fig. 6 shows the planimetric map according to the colored filter of a pixel cell of the present invention's second specific embodiment, shows that green and red time pixel region uses the situation of the photoresistance of different excitations respectively.This pixel cell is divided into pixel region: R three times, G, B, each time pixel region all is divided into echo area and penetrating region, thereby be divided into red reflex district R (r), green echo area G (r), blue echo area B (r) and red penetrating region R (t), green penetrating region G (t), blue penetrating region (t).

Use a kind of blue photoresistance 40R in B the pixel region.Use two kinds of green photoresistances in G the pixel region: the first green photoresistance 41G is positioned at green echo area G (r); The second green photoresistance 42G is positioned at green penetrating region G (t), and the excitation of the first green photoresistance 41G is low than the second green photoresistance 42G.Use two kinds of red photoresistances in R the pixel region: the first red photoresistance 41R is positioned at red reflex district R (r); The second red photoresistance 42R is positioned at red penetrating region R (t), and the excitation of the first red photoresistance 41R is low than the second blue photoresistance 42R.The echo area of time pixel region is the periphery that is positioned at penetrating region among Fig. 6.

The diagrammatic cross-section of Fig. 7 for looking along the 7-7 line of Fig. 6.See also Fig. 7, this semi-penetration semi-reflective LCD comprises first substrate, 10, the second substrates 30, and the liquid crystal layer 50 between first substrate 10 and second substrate 30.G time pixel region is divided into the first green photoresistance 41G and the second green photoresistance 42G, the then corresponding penetrating region electrode 22 of corresponding echo area electrode 21, the second green photoresistance 42G of the first green photoresistance 41G.R time pixel region also can be divided into the first red photoresistance 41R and the second red photoresistance 42R, and the then corresponding penetrating region electrode 22 of corresponding echo area electrode 21, the second red photoresistance 42R of the first red photoresistance 41R.

Because the excitation at the first green photoresistance 41G of echo area G (r) is low at the second green photoresistance 42G of penetrating region G (t), and be low in the excitation of the second red photoresistance 42B of penetrating region R (t) in the excitation of the first red photoresistance 41R of echo area R (r), therefore can reduce the color saturation of echo area, and make the color saturation of echo area and penetrating region reach unanimity.Semi-penetration semi-reflective LCD of the present invention, its chromatic photoresist can be made on first substrate 10 or second substrate 30.

In brief, the colored filter of above-mentioned second specific embodiment comprises: a kind of blue photoresistance 40B; Two kinds of

green photoresistance

41G and 42G, and the excitation of the green photoresistance 41G at place, echo area is lower than the excitation of the green photoresistance 42G at penetrating region place; And two kinds of

red photoresistance

41R and 42R, and the excitation of the red photoresistance 41R at place, echo area is lower than the excitation of the red photoresistance 42R at penetrating region place.

At this, the penetrating region electrode definition is the electrode in penetrating region, and the echo area electrode definition is the electrode in the echo area.

Computer Simulation:

(1) colored filter of the present invention's four coloured light resistance, it comprises: a kind of blue photoresistance; A kind of red photoresistance; Two kinds of green photoresistances, the excitation of the green photoresistance at place, echo area is lower than the excitation of the green photoresistance at penetrating region place.

(2) colored filter of the present invention's five colors photoresistance, it comprises: a kind of blue photoresistance; Two kinds of red photoresistances, the excitation of the red photoresistance at place, echo area is lower than the excitation of the red photoresistance at penetrating region place; Two kinds of green photoresistances, the excitation of the green photoresistance at place, echo area is lower than the excitation of the green photoresistance at penetrating region place.

(3) colored filter of prior art six coloured light resistances: two kinds of red photoresistances, two kinds of green photoresistances and two kinds of blue photoresistances, the excitation of the red, green, blue photoresistance of all kinds at place, echo area is low than the excitation of the red, green, blue photoresistance of all kinds at penetrating region place respectively.

The above-mentioned three kinds of colored filters of Computer Simulation, the graph of a relation of gained saturation degree (NTSC (%)) and brightness (Y) as shown in Figure 8.As seen from the figure, four coloured light resistance colored filter of the present invention and multicolored photoresistance colored filter still can be kept and the close chromatic characteristic of existing six coloured light resistance colored filter in the color saturation of echo area.Combine with above-mentioned, colored filter of the present invention is to use two kinds of chromatic photoresists on one or two time pixel region, and the excitation of the chromatic photoresist of echo area is low than the excitation of the chromatic photoresist of penetrating region.So, the present invention can reduce fabrication steps, and the color saturation at echo area and penetrating region is reached unanimity.

Though the present invention discloses as above with preferred embodiment; right its is not in order to limit the present invention; anyly have the knack of this skill person; without departing from the spirit and scope of the present invention; when can doing a little change and retouching, so protection scope of the present invention is as the criterion when looking appended the claim scope person of defining.

Claims

1. A color filter for a pixel unit, each pixel unit includes three sub-pixel areas of red, green and blue, each sub-pixel area is divided into a transmissive area and a reflective area, wherein the color filter In the green sub-pixel area include:

a first green photoresist located in the reflective area of the green sub-pixel region; and a second green photoresist located in the transmissive area of the green sub-pixel area,

Wherein the color purity of the first green photoresist is lower than that of the second green photoresist, and the thickness of the first green photoresist is the same as that of the second green photoresist; and

The color filter only includes a blue photoresist in the blue sub-pixel area, located in the reflection area and the transmission area of the blue sub-pixel area.

2. The color filter according to claim 1, wherein the red sub-pixel region comprises:

a first red photoresist located in the reflective area of the red sub-pixel area; and

a second red photoresist located in the penetrating region of the red sub-pixel region,

Wherein the color purity of the first red photoresist is lower than that of the second red photoresist, and the first red photoresist, the second red photoresist, the first green photoresist, the second green photoresist and the blue The thickness of the color photoresist is the same.

3. A color filter for a pixel unit, each pixel unit includes three sub-pixel areas of red, green and blue, and each sub-pixel area is divided into a transmissive area and a reflective area, wherein the color filter In the red sub-pixel area include:

a first red photoresist located in the reflective area of the red sub-pixel area;

a second red photoresist located in the penetration region of the red sub-pixel region, wherein the color purity of the first red photoresist is lower than that of the second red photoresist, and the first red photoresist the same thickness as the second red photoresist; and

4. A liquid crystal display, comprising:

A first substrate, which includes a plurality of pixel areas, each pixel area includes three sub-pixel areas of red, green and blue, and each sub-pixel area is divided into a transmissive area and a reflective area;

A plurality of pixel electrodes, including a transmissive region electrode and a reflective region electrode, are respectively located on the transmissive region and the reflective region of each sub-pixel region;

a second substrate corresponding to the first substrate;

a liquid crystal located between the first substrate and the second substrate; and

A color filter, located on the second substrate, facing the pixel electrode, and the color filter includes red, green and blue sub-pixel regions corresponding to the red, green and blue sub-pixel regions of the first substrate Three kinds of color photoresists, where the green sub-pixel area includes:

a first green photoresist located in the reflective area of the green sub-pixel area; and a second green photoresist located in the transmissive area of the green sub-pixel area, wherein the color purity of the first green photoresist is The color purity of the second green photoresist is lower than that of the second green photoresist, and the thickness of the first green photoresist is the same as that of the second green photoresist; and

The blue sub-pixel area only includes a blue photoresist located in the reflection area and the transmission area of the blue sub-pixel area, and the color photoresist is directly formed on the second substrate.

5. The liquid crystal display according to claim 4, wherein the red sub-pixel region comprises:

6. A liquid crystal display, comprising:

a second substrate;

A color filter, located on the second substrate, facing the pixel electrode, and the color filter includes red, green and blue sub-pixel regions corresponding to the red, green and blue sub-pixel regions of the first substrate Three kinds of color photoresists, where the red sub-pixel area includes:

a first red photoresist located in the reflective area of the red sub-pixel region; and a second red photoresist located in the transmissive area of the red sub-pixel area, wherein the color purity of the first red photoresist is The color purity of the second red photoresist is lower than that of the second red photoresist, and the thickness of the first red photoresist is the same as that of the second red photoresist;