JP2003255379A - Liquid crystal display panel, substrate for liquid crystal display panel and electronic appliance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display panel which can obtain both of brightness on the reflection type display and saturation on the transmission type display. <P>SOLUTION: This liquid crystal display panel has a plurality of sub pixels 5 corresponding to colors which are different to each other. Reflection layers 21 overlap one part of the respective sub pixels 5 and are disposed on second substrates 20 in such a manner that the total periphery is located within the sub pixels 5. On the other hand, color filters 12 are disposed on first substrates 10 which are located on the observer side so as to overlap the respective sub pixels 5. The respective color filters 12 have opening parts 121 in the regions 51 overlapping the reflection layers 21 in the sub pixels 5. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a liquid crystal display panel,
The present invention relates to a liquid crystal display panel substrate used for this liquid crystal display panel, and an electronic device using this liquid crystal display panel.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a so-called transflective liquid crystal display panel capable of switching between reflective display and transmissive display as needed. As shown in FIG. 13, in this type of liquid crystal display panel, a reflective layer 61 having an opening 611 is provided on the surface of the second substrate 20 that faces the first substrate 10 and holds the liquid crystal 31 therebetween. . Furthermore, the viewing side when viewed from the reflective layer 61 (the side where the viewer who visually recognizes the display image by the liquid crystal display panel is located)
Is provided with, for example, a color filter 62 colored in any one of red, green, and blue. Note that FIG.
3, electrodes for applying a voltage to the liquid crystal 31 and an alignment film for defining the alignment state of the liquid crystal 31 are not shown.

In this structure, incident light from the first substrate 10 side (for example, sunlight or indoor illumination light) is shown in FIG.
The first substrate 10 and the liquid crystal 3 are shown as a path R1 therein.
1 and the color filter 62 to reach the surface of the reflective layer 61. Then, the reflected light on this surface is transmitted through the color filter 62, the liquid crystal 31 and the first substrate 10 and emitted to the observing side, whereby a reflective display is performed. On the other hand, as shown as a route R2 in FIG.
Incident light from the substrate 20 side (e.g., irradiation light from the backlight unit) passes through the opening 611 of the reflective layer 61. Then, the light is transmitted through the color filter 62, the liquid crystal 31, and the first substrate 10 in this order and is emitted to the observing side, whereby a transmissive display is performed.

[0004]

However, in the conventional transflective liquid crystal display panel, the light visually recognized by the observer during the reflective display is reciprocated through the color filter 62.
In contrast to the light that has been transmitted once, the light visually recognized by the observer in the transmissive display passes through the color filter 62 only once. There was a problem that it became lower than the saturation of.

In the reflection type display, the brightness of the display tends to be insufficient due to the small amount of external light incident on the liquid crystal display panel.
It is desirable to increase the light transmittance of to secure a sufficient amount of light for display. However, the color filter 6
When the light transmittance of 2 is increased, the lack of saturation in the transmissive display becomes more remarkable. On the contrary, if the light transmittance of the color filter 62 is reduced in order to eliminate the lack of saturation in the transmissive display, the amount of light provided for the reflective display is reduced, and sufficient brightness of the display is secured. Will be difficult to do.

The present invention has been made in view of the circumstances described above, and is a liquid crystal display panel capable of ensuring both the brightness in reflective display and the saturation in transmissive display. An object of the present invention is to provide a liquid crystal display panel substrate used for a display panel and an electronic device using the liquid crystal display panel.

[0007]

In order to solve the above-mentioned problems, the present invention comprises a first substrate and a second substrate facing each other and sandwiching liquid crystal, and a plurality of sub-pixels corresponding to different colors are provided. In a liquid crystal display panel having the reflective layer, which is provided on the second substrate so as to overlap a part of each of the sub-pixels and have the entire peripheral edge located in the sub-pixels, and which reflects incident light from the first substrate side. A color filter which is provided so as to overlap with each of the sub-pixels on the observation side of the reflective layer and transmits light having a wavelength corresponding to the color of the sub-pixel, wherein the reflective layer is included in the sub-pixel. And a color filter having an opening in an overlapping region.

According to this liquid crystal display panel, since the opening is provided in the region of the color filter corresponding to the reflective layer, the amount of light provided for the reflective display can be sufficiently maintained and the light can be transmitted. It is also possible to maintain sufficient saturation when displaying the pattern. For example, even when the transmissivity of the color filter is lowered to improve the saturation in the transmissive display, a part of the light reflected by the reflective layer is passed through the opening of the color filter to reduce the light amount. Since the decrease can be suppressed, the brightness of the reflective display is maintained. In this liquid crystal display panel, the color filter may be provided on the first substrate. However, it goes without saying that the color filter may be provided on the second substrate.

Further, in the above liquid crystal display panel,
The area of the opening of the color filter corresponding to at least one color may be different from the area of the opening of the color filter corresponding to another color. In this way, the amount of light reflected on the surface of the reflective layer by the reflective layer and emitted to the viewing side during reflective display can be arbitrarily set for each sub-pixel of each color. For example, if the area of the opening provided in the color filter is selected according to the transmittance characteristic of each color filter, it is possible to compensate the variation in the transmittance characteristic for each color and realize good color reproducibility. Also, for example,
Even if the light emitted from the backlight unit has a variation in spectral characteristics (for example, the amount of light of each wavelength is different), the area of the opening provided in each color filter can be selected according to this spectral characteristic. It is possible to compensate for such variations and realize good color reproducibility. In addition, the area of the reflective layer corresponding to the sub-pixel of at least one color,
The same effect can be obtained when the areas of the reflective layers corresponding to the sub-pixels of other colors are different.

Further, in the liquid crystal display panel according to the present invention, in the sub-pixel, a reflection region corresponding to the reflection layer and a region other than the reflection region and incident from the second substrate side. It is preferable that the light-transmitting region that transmits light to the first substrate side is close to at least one side of a plurality of sides that define the sub-pixel and is adjacent to the side. In this case, it is conceivable that the at least one side of the sub-pixel is a pair of opposite sides among a plurality of sides that define the substantially rectangular sub-pixel.
According to this configuration, even if the peripheral portion of the sub-pixel cannot contribute to the display due to a manufacturing error, the area of both the reflective region and the translucent region is reduced. It is possible to prevent only one of these areas from decreasing in area. Therefore, even if a manufacturing error occurs, it is possible to avoid a situation in which the area ratio of the reflective area and the translucent area is different from the expected area ratio, and as a result, the display quality of the reflective display is improved. It is possible to maintain the balance between the display quality of the transmissive display and the display quality. For example, in a liquid crystal display panel having a light-shielding layer for shielding the surroundings of the sub-pixels, the light-shielding layer overlaps with a portion near the peripheral edge of the sub-pixel due to a manufacturing error, and the portion cannot contribute to display. There may be cases where Even in such a case, according to the present invention, it is possible to prevent the area ratio of the reflective region and the translucent region from being different from the intended (designed) area ratio.

Further, in a liquid crystal display panel in which an electrode for applying a voltage to the liquid crystal is provided on the second substrate, the reflective layer is made of a conductive material and electrically connected to the electrode. Is desirable. According to this configuration, only the electrodes are independent (separated from the reflective layer)
The resistance value can be suppressed as compared with the case where it is provided.

In order to solve the above problems, electronic equipment according to the present invention is characterized by including the above-mentioned liquid crystal display panel. As described above, according to the liquid crystal display panel of the present invention, it is possible to realize good display quality in both the reflective type and the transmissive type display systems. It is suitable for electronic devices that require switching to transmissive display and high display quality. As such an electronic device, for example, a portable personal computer or a mobile phone can be considered.

The present invention can also be implemented as a liquid crystal display panel substrate used in a liquid crystal display panel. That is, the liquid crystal display panel may be a liquid crystal display panel substrate provided on the back side of the liquid crystal display panel and provided with a reflective layer, or a reflective layer provided on the observing side of the liquid crystal display panel. It may be a substrate for a liquid crystal display panel that does not have it.

That is, the former liquid crystal display panel substrate has a plurality of sub-pixels corresponding to mutually different colors, is provided so as to overlap with each of the sub-pixels, and has a wavelength corresponding to the color of the sub-pixel. In a liquid crystal display panel substrate used for a liquid crystal display panel provided with a color filter that transmits light, one of a pair of substrates that sandwich liquid crystal facing each other, and a portion of each of the sub-pixels. A reflective layer which is provided on the one substrate so as to be overlapped and the entire periphery of which is located in the sub-pixel and which reflects incident light from the other substrate side of the pair of substrates, and which is provided on the color filter. And a reflection layer having a shape selected such that the provided opening is located in a region of the sub-pixel which overlaps with the reflection layer. In this liquid crystal display panel substrate, the color filter may be provided on the one substrate.

On the other hand, the liquid crystal display panel according to the latter is a substrate for a liquid crystal display panel used for a liquid crystal display panel having a pair of substrates facing each other and sandwiching liquid crystal, and a plurality of sub-pixels corresponding to mutually different colors. In one of the pair of substrates, a liquid crystal is sandwiched between the substrate and a substrate that overlaps a part of the sub-pixel and is provided with a reflective layer for reflecting light with the entire peripheral edge positioned in the sub-pixel. A substrate and provided on the one substrate so as to overlap with each of the sub-pixels,
A color filter that transmits light having a wavelength corresponding to the color of the sub-pixel, the color filter having an opening in a region of the sub-pixel that overlaps with the reflective layer.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. Such an embodiment shows one aspect of the present invention, does not limit the present invention, and can be arbitrarily modified within the scope of the present invention. In each drawing shown below, the scales are different for each layer and each member in order to make each layer and each member recognizable in the drawing.

<A: First Embodiment> First, a mode in which the present invention is applied to a passive matrix type transflective liquid crystal display panel will be described with reference to FIG. As shown in the figure, the liquid crystal display device includes a liquid crystal display panel 1 and a backlight unit 4. The liquid crystal display panel 1 is
The first substrate 10 and the second substrate 20 facing each other are bonded together with the sealing material 30 interposed therebetween, and, for example, TN (Twis
A liquid crystal 31 of ted nematic (ST) type or STN (Super Twisted Nematic) type is sealed. The backlight unit 4 is arranged on the second substrate 20 side of the liquid crystal display panel 1. Hereinafter, as shown in FIG. 1, the side opposite to the backlight unit 4 with respect to the liquid crystal display panel 1 is referred to as an “observation side”. That is, the "observation side" is
This means the side where the observer who visually recognizes the display image by the liquid crystal display panel 1 is located.

The backlight unit 4 has a light source 41 and a light guide plate 42. The light source 41 is, for example, an LED (Ligh
t Emitting Diode), a cold cathode tube, or the like, and emits light to the side end surface of the light guide plate 42. Light guide plate 42
Is a plate-shaped member for uniformly guiding the light from the light source 41 incident on the side end surface thereof to the substrate surface of the liquid crystal display panel 1. On the surface of the light guide plate 42 facing the liquid crystal display panel 1, a diffusion plate for evenly diffusing the light emitted from the light guide plate 42 with respect to the liquid crystal display panel 1 is attached. On the surface opposite to this, a reflection layer for adhering the light traveling from the light guide plate 42 to the side opposite to the liquid crystal display panel 1 to the liquid crystal display panel 1 side is attached (all are not shown). It should be noted that the light source 41 is not always lit, and when it is used in an environment in which outside light is not sufficiently present, it is lit according to an instruction from the user or a detection signal from the sensor.

On the other hand, the first substrate 10 and the second substrate 20 of the liquid crystal display panel 1 are plate-like members having a light transmitting property, such as glass, quartz and plastic. Of these, a retardation plate 101 for compensating interference colors and a polarizing plate 102 for polarizing incident light are attached to the outer surface of the first substrate 10 (the side opposite to the liquid crystal 31). . Second substrate 20
Similarly, the retardation plate 201 and the polarizing plate 202 are attached to the outer surface (the side opposite to the liquid crystal 31) of the.

A plurality of common electrodes 14 are provided on the surface of the first substrate 10. Here, FIG. 2 is a plan view showing the configuration of a part of the elements constituting the liquid crystal display panel 1. The sectional view taken along the line AA 'in FIG. 2 corresponds to FIG. As shown in FIGS. 1 and 2, each common electrode 14 is a strip-shaped electrode formed of a transparent conductive material such as ITO (Indium Tin Oxide) and extends in the X direction shown in the drawing.

On the other hand, a plurality of segment electrodes 22 are provided on the surface of the second substrate 20. Each segment electrode 22 is a strip-shaped electrode formed of a transparent conductive material such as ITO like the common electrode 14, and as shown in FIGS. 1 and 2, a direction intersecting with the common electrode 14 (that is, in the figure). Extending in the Y direction). As shown in Figure 1,
The surface of the first substrate 10 having the common electrode 14 formed thereon and the surface of the second substrate 20 having the segment electrode 22 formed thereon are covered with alignment films 15 and 23, respectively. The alignment films 15 and 23 are organic thin films formed of, for example, polyimide or the like, and have been subjected to a rubbing treatment for defining the alignment state of the liquid crystal 31 when no voltage is applied.

The liquid crystal 31 sandwiched between the first substrate 10 and the second substrate 20 includes a common electrode 14 and a segment electrode 2.
The orientation direction changes depending on the voltage applied between the two. Hereinafter, as shown in the lower right part of FIG. 2, the region 5 where the common electrode 14 and the segment electrode 22 face each other is referred to as a “sub pixel”. That is, it can be said that the sub-pixel 5 is the minimum unit of the region in which the alignment direction of the liquid crystal 31 changes according to the application of the voltage. As shown in FIG. 2, the plurality of sub-pixels 5 are arranged in a matrix shape in the X direction and the Y direction, and each corresponds to any one of red (R), green (G), and blue (B) colors. To do. Then, a group of three sub-pixels 5R, 5G and 5B corresponding to these three colors constitutes one pixel (dot) corresponding to the minimum unit of the display image.

Next, as shown in FIG. 1, a light shielding layer 11, a color filter 12 and an overcoat layer 13 are formed on the inner surface (on the side of the liquid crystal 31) of the first substrate 10. Of these, the overcoat layer 13 is formed of, for example, a resin material such as an acrylic resin or an epoxy resin, and plays a role of flattening the step between the light shielding layer 11 and the color filter 12. The common electrode 14 described above is formed on the surface of the overcoat layer 13.

The light-shielding layer 11 is formed in a grid pattern so as to cover the gaps between the sub-pixels 5 arranged in a matrix (that is, the regions other than the region where the common electrode 14 and the segment electrodes 22 face each other), and each sub-pixel has a structure. It plays a role of shielding the periphery of the pixel 5. The light shielding layer 11 is formed of, for example, a black resin material in which carbon black is dispersed or a metal such as chromium (Cr).

Next, the color filters 12 (12R, 12R)
G and 12B) are resin layers formed corresponding to the respective sub-pixels 5, and are colors corresponding to the colors of the sub-pixels 5 by dyes or pigments, that is, red (R), green (G) and blue (B). ) Are each colored. Therefore, of the light transmitted through the liquid crystal 31 toward the first substrate 10, the light having the wavelength corresponding to the color of each color filter 12 is selectively emitted to the observation side. Further, the color filter 12 is provided with an opening 121 corresponding to the vicinity of the central portion of each sub-pixel 5 as shown in FIG. 1, which will be described later. In the present embodiment, a case where a configuration in which the color filters 12 of the same color are arranged over a plurality of sub-pixels 5 forming a column in the Y direction (so-called stripe arrangement) is adopted is illustrated.

FIG. 3 is a graph showing the transmittance characteristics of the color filter 12 used in this embodiment. In FIG. 3, the wavelength of the incident light on the color filter 12 is shown on the horizontal axis, and the transmittance (ratio of the emitted light quantity to the incident light quantity) is shown on the vertical axis. As shown in the figure, the color filter 12R has a color filter of about 600n corresponding to red.
The color filter 12G has a high transmittance for light having a wavelength of m or more, and the color filter 12G has a high transmittance for light having a wavelength of about 500 to 600 nm corresponding to green.
2B has a high transmittance for light having a wavelength of about 400 to 500 nm corresponding to blue. And
Comparing the maximum transmittances of the color filters 12 in the graph of FIG. 3, the maximum transmittance of the red color filter 12R (about 0.92) is the largest, and the maximum transmittance of the blue color filter 12B (about 0. 89), and the maximum transmittance (about 0.84) of the green color filter 12G decreases in that order. That is, when the same amount of light is applied to the color filters 12 of the respective colors, the amount of light emitted from the green color filter 12G is smaller than the amount of light emitted from the red color filter 12R and the blue color filter 12B.

On the other hand, as shown in FIGS. 1 and 2, the second
A plurality of reflective layers 2 are formed on the inner surface (the liquid crystal 31 side) of the substrate 20.
1 is provided. Each reflective layer 21 is a layer for reflecting incident light from the first substrate 10 side, and has a light reflectivity formed of, for example, a single metal such as aluminum or silver or an alloy containing these as a main component. It is a thin film. The reflection layer 21 in the present embodiment is assumed to be formed of an alloy containing silver (Pd) and copper (Cu) as a main component. In addition, the second substrate 2
The inner surface of 0 has a scattering structure (unevenness) on the surface of the reflective layer 21.
However, it is not shown in the drawing. Instead of the structure in which the scattering structure is formed on the surface of the reflective layer 21, a so-called forward scattering method in which the polarizing plate 102 on the observation side has a scattering characteristic may be adopted.

FIG. 4 is a view showing the positional relationship between each reflective layer 21 and the segment electrode 22, and is a cross section taken along the line BB 'in FIG. 2 (that is, the segment electrode 2).
It is a figure which shows the structure seen from the cross section orthogonal to the extending direction of FIG. As shown in the figure, the reflective layer 21 is covered with the segment electrode 22 over the entire periphery of the cross section orthogonal to the segment electrode 22. More specifically, as shown in FIG. 4, the first layer 22 forming a part of the segment electrode 22.
1 is formed on the inner surface of the second substrate 20, and the reflective layer 21 is formed so as to cover a part of the first layer 221 in the width direction. Further, the segment electrode 22
Is formed so as to cover the reflection layer 21 from the surface of the reflection layer 21 parallel to the second substrate 20 to the peripheral edge portion (edge) in the width direction. With this configuration, the segment electrode 22 and the reflective layer 21 are electrically connected. The ITO forming the segment electrodes 22 has a relatively high resistance value, whereas the APC alloy forming the reflective layer 21 has a low resistance value. Therefore, the wiring resistance can be suppressed low by bringing the segment electrode 22 and the reflective layer 21 into contact with each other as shown in FIG.

On the other hand, focusing on the plane parallel to the substrate surface of the second substrate 20 as shown in FIG. 2, each of the plurality of reflective layers 21 is provided so as to overlap a part of each sub-pixel 5.
Furthermore, the entire periphery of each reflective layer is located within the sub-pixel 5. In other words, each reflective layer 21 is
The sub-pixels 5 are provided in the sub-pixels 5 so as to be separated from each other in an island shape.

A region of the sub-pixel 5 that overlaps with the reflective layer 21 (hereinafter referred to as "reflective region 51") functions as a region for reflecting light from the first substrate 10 side to perform reflective display. To do. That is, when performing reflection type display, outside light such as sunlight or indoor illumination light that has entered the liquid crystal display panel 1 from the viewing side is not affected by the polarizing plate 102 and the retardation plate 1.
After passing through 01 to enter a predetermined polarization state, the first substrate 10 → color filter 12 → common electrode 1
The reflective layer 21 travels through the path of 4 → liquid crystal 31 → segment electrode 22 and is reflected on the surface of the reflective layer 21 to follow the path that has just come in reverse. At this time, the common electrode 1
4 depending on the voltage difference between the segment electrode 22 and the segment electrode 22.
Since the alignment state of No. 1 changes, the amount of light of the reflected light in the reflective region 51 that is visible to the viewer through the polarizing plate 102 is controlled for each sub-pixel 5.

On the other hand, a region of the sub-pixel 5 other than the reflective region 51, that is, a region other than the region of the sub-pixel 5 covered with the reflective layer 21 (hereinafter referred to as "translucent region").
Reference numeral 52 functions as a region for transmitting light that has entered the second substrate 20 from the backlight unit 4 to perform transmissive display. That is, when the light source 41 of the backlight unit 4 is turned on to perform the transmissive display, the irradiation light of the backlight unit 4 passes through the polarizing plate 202 and the retardation plate 201 to be in a predetermined polarization state. After that, the light is emitted to the observation side through the path of the second substrate 20 → (transparent region 52 →) segment electrode 22 → liquid crystal 31 → common electrode 14 → color filter 12 → first substrate 10. Also in this transmissive display, since the alignment state of the liquid crystal 31 changes according to the voltage difference between the common electrode 14 and the segment electrode 22, the light transmitted through the translucent region 52 passes through the polarizing plate 102. The amount of light seen by the observer is
It is controlled for each sub-pixel 5.

Next, referring to FIG. 5, a more detailed structure of the reflective layer 21 and the color filter 12 will be described. In addition, in FIG.
Only the color sub-pixels 5 are shown.

As described above, each sub-pixel 5 corresponds to the reflection layer 21 and reflects the incident light from the first substrate 10 side, and the sub-pixel 5 corresponds to the area other than the reflection layer 21 and the second area. And a light-transmitting region 52 for transmitting incident light from the substrate 20 side to the first substrate 10 side. As shown in FIG. 5, the color filter 12 for each color is provided with an opening 121 in a region of the sub-pixel 5 corresponding to the reflective region 51. The opening 121 is a portion where the color filter 12 is not provided, and the transparent overcoat layer 13 that covers the color filter 12 and the light shielding layer 11 enters the opening 121. In such a configuration, of the light reflected on the surface of the reflective layer 21 when the reflective display is performed, the color filter 12 (the portion other than the opening 121)
The amount of the light transmitted through the color filter 12 is reduced by the action of the color filter 12, whereas the light emitted to the first substrate 10 side through the opening 121 of the color filter 12 passes through the transparent overcoat layer 13. The amount of light is hardly reduced because it is only transmitted. Therefore, for example, when the light transmittance of the color filter 12 is increased in order to secure the saturation in the transmissive display (that is, when the dispersion amount of the pigment or dye in the color filter 12 is increased).
Even in this case, it is possible to obtain a bright display by sufficiently securing the amount of light provided for the reflective display. As described above, according to this embodiment, it is possible to secure both the brightness in the reflective display and the saturation in the transmissive display.

Next, in the present embodiment, as shown in FIG. 5, the opening 121 provided in the color filter 12 is formed.
Area is different for each color filter 12 of each color. That is, the area of the opening 121 provided in the green color filter 12G is equal to the area of the red color filter 12R.
And larger than the area of the opening 121 provided in the blue color filter 12B. Here, as described above with reference to FIG. 3, the green color filter 12G
Has a lower maximum transmittance than that of the red color filter 12R and the blue color filter 12B. That is, the area of the opening 121 of each color filter 12 is selected according to the difference in the transmittance characteristics of each color filter 12.

Further, as shown in FIGS. 2 and 5, the area ratio between the reflective area 51 and the translucent area 52 also differs depending on the difference in the transmittance characteristics of each color filter 12. In other words, the area of the reflective layer 21 corresponding to each sub pixel 5 differs depending on the color of the sub pixel 5. Specifically, the area of the reflective region 51 (or the reflective layer 21) corresponding to the green subpixel 5G is smaller than the area of the reflective region 51 (or the reflective layer 21) corresponding to the red and blue subpixels 5R and 5B. Is also getting bigger.

In this way, by making the area of the opening 121 of the color filter 12 and the area of the reflective layer 21 different for each sub-pixel 5 of each color, each color filter 12 is different.
There is an advantage that a good display quality can be secured by compensating for the difference in the transmittance characteristics of the above. Hereinafter, this effect will be described in detail.

First, pay attention to the area of the opening 121 provided in each color filter 12. Since the maximum transmittance of the green color filter 12G is lower than the maximum transmittance of the color filters 12 of other colors, if the openings 121 having the same area are provided for all the color filters 12, the green color filters 12G have the same transmittance. The amount of light transmitted through the filter 12G is red and blue color filters 12R and 12
It becomes smaller than the amount of light transmitted through B. Therefore, the amount of light visually perceived by an observer for each color of red, green, and blue in the reflective display may vary, and it may be difficult to realize good color reproducibility. On the other hand, in the present embodiment, since the green color filter 12G having a low transmittance is provided with the opening 121 having a larger area than the other color filters 12R and 12B, the red color in the reflective display, It is possible to maintain the balance of the amount of light visually recognized by the observer for each of the colors of green and blue.

Next, pay attention to the area of the reflective layer 21 of each sub-pixel 5. Since the maximum transmittance of the green color filter 12G is lower than the maximum transmittance of the color filters 12 of other colors, it is assumed that the reflective regions 51 of the sub-pixels 5 of all colors are assumed.
If the areas are equal, the amount of light reflected on the surface of the reflective layer 21 corresponding to the green sub-pixel 5 and emitted to the observation side is reflected on the surface of the reflective layer 21 corresponding to the sub-pixels 5 of other colors. As compared with the amount of light emitted to the observing side, the amount of light of each color visually recognized by the observer varies. On the other hand, in the present embodiment, the green sub-pixel 5G
Since the area of the reflective layer 21 corresponding to is larger than the area of the reflective layer 21 of the other sub-pixels 5R and 5B, the light is reflected by the surface of the reflective layer 21 corresponding to the green sub-pixel 5G and is observed. It is possible to secure a sufficient amount of light to be emitted to.

As described above, according to the present embodiment, even if the transmittance characteristics of the color filters 12 of the respective colors are varied, this is compensated for and good color reproducibility is realized.

Referring again to FIG. 5, focusing on the positional relationship between each sub-pixel 5 and the reflection area 51 and the light-transmissive area 52 in the sub-pixel 5, in the present embodiment, the reflection area 51 and the light-transmissive area 52. Both define a sub-pixel 5 4
Of the sides of the book (that is, the four sides forming the periphery of the sub-pixel 5), the areas are close to a pair of sides extending in the Y direction, and the areas are adjacent to each other along the sides. That is, when each of the two long sides of the substantially rectangular sub-pixel 5 is traced from one end to the other end of the side, the translucent area 52, the reflective area 51, and the translucent area are along the side. The areas are adjacent to each other in the order of the area 52. In other words, as shown in FIG. 5, close to the long side of the sub-pixel 5,
In addition, when a straight line L parallel to the side is assumed in the sub-pixel 5, the straight line L passes through both the reflective area 51 and the translucent area 52.

As described above, in this embodiment, the reflective area 51 and the transparent area 52 corresponding to one sub-pixel 5 are provided.
Are adjacent to each other along the peripheral edge of the sub-pixel 5, so that the area ratio of the reflective region 51 and the translucent region 52 in the sub-pixel 5 varies due to a manufacturing error. Can be suppressed. The details are as follows.

As a structure for including the reflective region 51 and the translucent region 52 in one sub-pixel 5, for example, the structure shown in FIG. 6A can be considered. In other words, the reflective layer 21 so that the peripheral edge of the reflective layer 21 corresponding to each sub-pixel 5 does not come close to the peripheral edge of the sub-pixel 5, in other words, the translucent area 52 only comes close to the peripheral edge of each sub-pixel 5. 21 is formed.

Here, in the process of manufacturing the liquid crystal display panel 1 having such a structure, a process of bonding the second substrate 20 having the reflective layer 21 formed thereon and the first substrate 10 having the light shielding layer 11 formed thereon is performed. Pay attention. In this step, it is general that the substrates are bonded to each other while the relative alignment between the substrates is performed. At this time, assuming that the relative positions of the two substrates in the X direction are displaced due to, for example, manufacturing engineering reasons, as shown in FIG. Part of the light shielding layer 1
It will be covered by 1. Thus, the light shielding layer 11
Since the portion covered by is not able to contribute to the display, the area of the light-transmitting region 52 occupying the sub-pixel 5 is when the light-shielding layer 11 is appropriately arranged (that is, the case of FIG. 6A). Will be smaller than On the other hand, since the reflective region 51 is not close to the peripheral edge of the region, the reflective region 51 is not covered with the light shielding layer 11 even when the displacement of the substrate occurs. That is, the area of the reflective region 51 in the sub-pixel 5 is the same as that shown in FIG. 6A. As described above, in the configuration shown in FIG. 6, the area of the translucent region 52 decreases while the area of the reflective region 51 does not change due to the bonding error of the substrates.
The area ratio between the reflective area 51 and the translucent area 52 becomes different from the expected area ratio. As a result, the brightness of the transmissive display becomes darker than that of the reflective display, so that the brightness varies depending on the display method.

On the other hand, in the present embodiment, the reflective area 51 and the translucent area 52 are adjacent to each other in the vicinity of a plurality of sides defining one sub-pixel 5 along the side. . Therefore, when the relative positions of the first substrate 10 and the second substrate 20 deviate in the X direction from the appropriate position (designed position) shown in FIG.
As shown in (b), the area of the translucent area 52 and the area of the reflective area 51 are reduced. That is, according to the present embodiment, even when the relative positions of the reflective layer 21 and the light shielding layer 11 are deviated, only the area of either the transparent region 52 or the reflective region 51 is reduced. Therefore, it is possible to prevent the area ratio of the reflective region 51 and the translucent region 52 from deviating from a desired value.

<B: Second Embodiment> Next, the second embodiment of the present invention will be described.
The liquid crystal display panel according to the embodiment will be described. In the first embodiment, the first substrate 1 located on the observation side
The structure in which the light-shielding layer 11, the color filter 12, and the overcoat layer 13 are provided on the substrate 0 is illustrated. On the other hand, in the present embodiment, these elements are the second substrate 2
0 is provided above.

FIG. 8 is a cross-sectional view showing the structure of the liquid crystal display panel according to this embodiment, and FIG. 9 is a plan view and cross-section showing the positional relationship between the sub-pixels, color filters and reflective layers in this liquid crystal display panel. It is a figure. Among the constituent elements shown in FIGS. 8 and 9, the same constituent elements as those of the liquid crystal display panel 1 according to the first embodiment are designated by the same reference numerals.

As shown in FIGS. 8 and 9, the second substrate 2
On the surface of 0, a plurality of reflective layers 21 each corresponding to the sub-pixel 5 are formed. These reflective layers 21 are the same as those shown in the first embodiment. That is, as shown in FIG. 9, the reflective layer 21 is formed inside the peripheral edge of each sub-pixel 5, and the reflective area 51 and the translucent area 52 are adjacent to each other along the peripheral edge of each sub-pixel 5. And the area of the reflection layer 21 corresponding to the green sub-pixel 5G has the other colors.
It is larger than the area of the reflective layer 21 corresponding to B.

Then, on the surface of the second substrate 20 on which the plurality of reflection layers 21 are formed, the light-shielding layer 11 overlapping the gaps between the sub-pixels 5 and the color filter 12 (12R) colored in the color of each sub-pixel 5 are formed. , 12G, 12B) are provided.
As shown in FIG. 9, an opening 121 is provided in a region of each color filter 12 corresponding to the reflection region 51. Similar to the first embodiment, the area of each opening 121 is different for each sub-pixel 5 of each color. That is, as shown in FIG. 9, the area of the opening 121 corresponding to the green sub-pixel 5G is the red and blue sub-pixels 5R.
And larger than the area of the opening 121 corresponding to 5B.

Further, the surface of the second substrate 20 provided with the reflective layer 21, the light shielding layer 11 and the color filter 12 is covered with the overcoat layer 13, and the segment electrode 22 is formed on the surface of the overcoat layer 13. Has been done. This segment electrode 22 is made of a single layer of transparent conductive material, unlike the configuration shown in FIG. 4 (the configuration of the first layer 221 and the second layer 222). The surface of the overcoat layer 13 provided with the segment electrodes 22 is covered with the alignment film 23.

On the other hand, as shown in FIG. 8, a common electrode 14 is formed on the inner surface of the first substrate 10, and the common electrode 14 is covered with an alignment film 15. Note that FIG.
In the cross-sectional view of FIG. 1, the illustration of each element on the first substrate 10 is omitted.

With the structure in which the light shielding layer 11 and the color filter 12 are provided on the second substrate 20 as described above, the same effect as that of the first embodiment can be obtained. That is, as shown in the first and second embodiments, it is determined which of the first substrate 10 located on the observation side and the second substrate 20 located on the back side is provided with the color filter 12. The present invention can be applied regardless of the situation. However, the light shielding layer 11 and the color filter 12
Is generally formed with relatively high accuracy by using photolithography, etching technology, or the like. Therefore, compared with the case where the light shielding layer 11 is formed on the first substrate 10,
It can be said that a situation in which the relative position of the reflective layer 21 and the light shielding layer 11 is displaced is unlikely to occur. In consideration of this situation, the advantage of being able to suppress the error in the area ratio between the reflective region 51 and the translucent region 52 described with reference to FIGS. 6 and 7 is that the light shielding layer 11 (and the color filter 12) is It can be said that it appears particularly remarkably when formed on one substrate 10.

<C: Modification> Although one embodiment of the present invention has been described above, the above embodiment is merely an example, and various modifications can be made to the above embodiment without departing from the spirit of the present invention. Can be added. For example, the following may be considered as modifications.

<C-1: Modification 1> In each of the above embodiments, in order to compensate for the difference in the transmittance characteristics of the color filters 12 of the respective colors, the reflective layer 2 corresponding to the green sub-pixel 5G.
The area of 1 and the area of the opening 121 of the color filter 12G are made different from those of the red sub-pixel 5G and the blue sub-pixel 5B, but for each of red, green and blue. These areas may be different. Further, in each of the above-described embodiments, the area of the reflective layer 21 and the area of the opening 121 of the color filter 12 corresponding to the sub-pixel of each color are set to the color filter 12.
However, it may be changed according to the spectral characteristic of the irradiation light from the backlight unit. That is, for example, when there are variations in the spectral characteristics of the irradiation light from the backlight unit 4 such that the amount of light of the wavelength corresponding to blue is smaller than the amount of light of the wavelength corresponding to green and red, the blue sub-pixels By making the area of the reflective layer 21 corresponding to 5B smaller than the area of the reflective layer 21 corresponding to the sub-pixel 5 of another color, a wide light-transmitting area 52 of the sub-pixel 5B may be secured. . As described above, the elements for determining the area of the reflective layer 21 and the area of the opening 121 of the color filter 12 corresponding to each sub-pixel 5 are not limited to the transmittance characteristics of the color filter 12. On the other hand, in the present invention, the area of the reflective layer 21 of each sub-pixel 5 and the area of the opening 121 of the color filter 12 do not necessarily have to be different.

<C-2: Modification 2> In the first embodiment, as shown in FIG. 4, the reflective layer 21 is in contact with the segment electrodes 22. However, it is necessary to contact them. Not necessarily. That is, as shown in FIG. 10, the surface of the second substrate 20 provided with the reflective layer 21 is covered with an insulating layer 25 made of a resin material or the like, and a single layer of a transparent conductive film is formed on the surface of the insulating layer 25. Alternatively, the segment electrode 22 may be provided.

<C-3: Modification 3> In the above embodiment, a passive matrix type liquid crystal display panel having no switching element has been exemplified, but a TFD (Thin Fil) is used.
2 terminal type switching element typified by m Diode),
The present invention can be applied to an active matrix type liquid crystal display panel including a three-terminal switching element represented by a TFT (Thin Film Transistor) as in the above embodiment. Further, in each of the above-described embodiments, the case where the color filter 12 of the same color adopts a stripe array in which one row is used is illustrated. However, as a mode of the array of the color filter 12, a mosaic array or a delta array is also available. It can also be adopted.

<D: Electronic Device> Next, an electronic device using the liquid crystal display panel according to the present invention will be described.

<D-1: Mobile Computer> First, an example in which the liquid crystal display panel according to the present invention is applied to the display portion of a portable personal computer (so-called notebook personal computer) will be described. FIG. 11 is a perspective view showing the configuration of this personal computer. As shown in the figure, the personal computer 91 includes a main body portion 912 having a keyboard 911 and a display portion 913 to which the liquid crystal display panel according to the present invention is applied.

<D-2: Mobile Phone> Next, an example in which the liquid crystal display panel according to the present invention is applied to the display portion of a mobile phone will be described. FIG. 12 is a perspective view showing the configuration of this mobile phone. As shown in FIG.
2 includes a plurality of operation buttons 921, an earpiece 922,
A mouthpiece 923 and a display unit 924 to which the liquid crystal display panel according to the present invention is applied are provided.

As the electronic apparatus to which the liquid crystal display panel according to the present invention can be applied, in addition to the personal computer shown in FIG. 11 and the mobile phone shown in FIG. 12, a liquid crystal television, a viewfinder type monitor, etc. Direct-view video tape recorders, car navigation devices, pagers, electronic organizers, calculators, word processors, workstations, videophones, POS terminals, digital still cameras and the like can be mentioned. According to the liquid crystal display panel of the present invention, it is possible to maintain both the brightness in reflective display and the saturation in transmissive display, and it is possible to maintain good display quality in both display systems. Therefore, it is particularly suitable for an electronic device that requires good display quality by both the reflection type and the transmission type.

[0060]

As described above, according to the present invention,
It is possible to secure both the brightness in the reflective display and the saturation in the transmissive display.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a liquid crystal display panel according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a relationship with a common electrode, a segment electrode and a reflective layer in the liquid crystal display panel.

FIG. 3 is a graph showing a transmittance characteristic of a color filter in the liquid crystal display panel.

FIG. 4 is a sectional view showing a relationship between a segment electrode and a reflective layer in the liquid crystal display panel.

5A and 5B are a plan view and a cross-sectional view showing a positional relationship between a sub pixel, a color filter, and a reflective layer in the liquid crystal display panel.

FIG. 6 is a diagram showing contrast for explaining the effect of the embodiment.

FIG. 7 is a diagram for explaining the effect of the same embodiment.

FIG. 8 is a cross-sectional view showing a configuration of a liquid crystal display panel according to a second embodiment of the present invention.

9A and 9B are a plan view and a cross-sectional view showing a positional relationship between a sub pixel, a color filter, and a reflective layer in the liquid crystal display panel.

FIG. 10 is a cross-sectional view showing a configuration of a liquid crystal display panel according to a modification of the present invention.

FIG. 11 is a perspective view showing a configuration of a personal computer as an example of an electronic device to which the liquid crystal display panel according to the present invention is applied.

FIG. 12 is a perspective view showing a configuration of a mobile phone as an example of an electronic device to which the liquid crystal display panel according to the present invention is applied.

FIG. 13 is a cross-sectional view showing a configuration of a conventional transflective liquid crystal display panel.

[Explanation of symbols]

1, 1 '... Liquid crystal display panel, 10 ... First substrate, 11
... light-shielding layer, 12 (12R, 12G, 12B) ... color filter, 121 ... opening, 13 ... overcoat layer, 14 ... common electrode, 15, 23 ... alignment film, 2
0 ... Second substrate, 21 ... Reflecting layer, 22 ... Segment electrode, 221 ... First layer, 222 ... Second layer, 30 ...
Sealing material, 31 ... Liquid crystal, 101, 201 ... Phase difference plate, 102, 202 ... Polarizing plate, 4 ... Backlight unit, 41 ... Light source, 42 ... Light guide plate, 5 (5R, 5)
G, 5B) ... Sub pixel, 51 ... Reflection area, 52 ...
Transparent region, 91 ... Personal computer (electronic device), 92 ... Mobile phone (electronic device).

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09F 9/30 338 G09F 9/30 338 349 349 349B 9/35 9/35 F term (reference) 2H048 BA02 BB02 BB07 BB10 BB44 2H091 FA02Y FA08X FA08Z FA14Y FA41Z LA15 LA17 LA18 2H092 GA13 HA03 HA05 JB51 NA01 NA07 PA02 PA08 PA09 PA11 PA12 PA13 5C094 AA51 BA03 BA43 CA19 CA20 CA24 DA20 EA04 EA05 EA07 ED03

Claims (12)

[Claims] 1. A liquid crystal display panel comprising a first substrate and a second substrate which face each other and sandwich a liquid crystal, and which has a plurality of sub-pixels corresponding to different colors, and overlaps with a part of each of the sub-pixels. A reflective layer that is provided on the second substrate such that the entire periphery is located in the sub-pixel, and that reflects incident light from the first substrate side; and the sub-pixels on the observation side of the reflective layer. A color filter which is provided so as to overlap and transmits light having a wavelength corresponding to the color of the sub-pixel, the color filter having an opening in a region of the sub-pixel which overlaps with the reflection layer. Liquid crystal display panel characterized by. 2. The liquid crystal display panel according to claim 1, wherein the color filter is provided on the first substrate. 3. An area of an opening of a color filter corresponding to at least one color and an area of an opening of a color filter corresponding to another color are different.
The liquid crystal display panel described in. 4. The liquid crystal display according to claim 1, wherein the area of the reflective layer corresponding to the sub-pixels of at least one color is different from the area of the reflective layer corresponding to the sub-pixels of the other color. panel. 5. A reflective region of the sub-pixel corresponding to the reflective layer, and a translucent region that is a region other than the reflective region and that transmits incident light from the second substrate side to the first substrate side. The liquid crystal display panel according to claim 1, wherein the region is adjacent to at least one side of the plurality of sides defining the sub-pixel and is adjacent along the side. 6. The liquid crystal according to claim 5, wherein the at least one side of the sub-pixel is a pair of sides facing each other among a plurality of sides defining the substantially rectangular sub-pixel. Display panel. 7. The liquid crystal display panel according to claim 5, further comprising a light blocking layer that blocks light around the sub-pixels. 8. An electrode provided on the second substrate for applying a voltage to the liquid crystal, wherein the reflective layer has conductivity and is electrically connected to the electrode. The liquid crystal display panel according to claim 1. 9. An electronic device comprising the liquid crystal display panel according to claim 1. 10. A liquid crystal having a plurality of sub-pixels corresponding to mutually different colors, the liquid crystal having a color filter provided so as to overlap with each of the sub-pixels and transmitting light having a wavelength corresponding to the color of the sub-pixel. In a liquid crystal display panel substrate used for a display panel, one substrate of a pair of substrates facing each other and sandwiching liquid crystal, and a portion of each of the sub-pixels and the entire peripheral edge within the sub-pixels. A reflective layer which is provided on the one substrate so as to be positioned and reflects incident light from the other substrate side of the pair of substrates, and the opening provided on the color filter is the sub-pixel of the sub-pixel. A reflective layer having a shape selected so as to be located in a region overlapping with the reflective layer. 11. The substrate for a liquid crystal display panel according to claim 10, wherein the color filter is provided on the one substrate. 12. A substrate for a liquid crystal display panel, which is used in a liquid crystal display panel having a pair of substrates facing each other and sandwiching liquid crystal, and a plurality of sub-pixels corresponding to mutually different colors. A substrate which overlaps a part of the sub-pixel and has a liquid crystal sandwiched between the substrate and a substrate provided with a reflective layer for reflecting light, the entire periphery of which is located in the sub-pixel; A color filter which is provided on the one substrate so as to overlap and transmits light having a wavelength corresponding to the color of the sub-pixel, the color filter having an opening in a region of the sub-pixel overlapping with the reflection layer. A substrate for a liquid crystal display panel, comprising: