JP2003344840A - Liquid crystal device and electronic equipment using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide scattering property to reflected display light even when a pixel size is reduced, and to optimize retardation of a liquid crystal layer in both a transmissive display area and a reflective display area. To provide a liquid crystal device and an electronic device that can be used. SOLUTION: In a counter substrate 10 of a transflective liquid crystal device 100, a transmissive display color filter 241 having a wide chromaticity range is formed in a transmissive display region 100c, and the reflective display region 10 is formed.
The reflective display color filter 242 having a narrow chromaticity range is formed at 0b. The reflective display color filter 242 is blended with fine light scattering particles 29 in addition to various color materials, and imparts light scattering properties to the reflected display light. Color filter for reflective display 2
Reference numeral 42 indicates that the chromaticity range is narrow but formed thick, and the layer thickness d of the liquid crystal layer 50 in the reflective display region 100b is considerably smaller than that in the transmissive display region 100c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflective liquid crystal device,
The present invention relates to a transflective liquid crystal device and an electronic device including the same. More specifically, the present invention relates to a technique for imparting a light scattering property to a reflective display area.

[0002]

2. Description of the Related Art There is a reflection type liquid crystal device as a typical one used as a direct view type display device in a mobile phone, a mobile computer or the like. In this reflective liquid crystal device,
A total reflection type display device that displays images only in reflection mode,
There is a transflective liquid crystal device that displays an image in both a transmissive mode and a reflective mode, and the latter is disclosed in Japanese Patent Application Laid-Open No. 11-044814.

In the transflective liquid crystal device, for example, as shown in a schematic plan view of a pixel in FIG.
A reflective display area 100b and a rectangular window-shaped transmissive display area 100c are formed in the pixel 100a partitioned by the scanning line 3a.

The one shown here is a thin film transistor (hereinafter, referred to as TFT (Thin) as a pixel switching element.
Film Transistor), and as shown in FIG. 12, a pixel electrode 9a having a transparent surface is used.
(First transparent electrode), and pixel switching TFT
The TFT array substrate 10 (first transparent substrate) on which the counter electrode 30 is formed, the counter electrode 21 (second transparent electrode), and the counter substrate 20 (second transparent substrate) on which the light shielding film 23 is formed.
And the liquid crystal layer 5 held between these substrates 10, 20
It has 0 and. TFT array substrate 10 and counter substrate 2
The distance between the substrate and 0 is obtained by spraying the gap material 5 having a predetermined particle size on the surface of one of the substrates and then bonding the TFT array substrate 10 and the counter substrate 20 with each other through a sealing material (not shown). It is prescribed.

The TFT array substrate 10 has a pixel electrode 9a.
The light reflection layer 8a constituting the reflection display area 100b is formed in the pixel 100 where the light reflection layer 8a and the counter electrode 21 face each other, and the remaining area where the light reflection layer 8a is not formed (light transmission window 8).
The transmissive display area 100c is constituted by d).

Therefore, of the light emitted from the backlight device (not shown) arranged on the back side of the TFT array substrate 10, the light incident on the transmissive display area 100c is the TFT as shown by the arrow LB. The light enters the liquid crystal layer 50 from the array substrate 10 side, is optically modulated by the liquid crystal layer 50, and then is emitted as transmission display light from the counter substrate 20 side to display an image (transmission mode).

On the other hand, of the external light incident from the counter substrate 20 side, the light incident on the reflective display area 100b reaches the reflective layer 8a through the liquid crystal layer 50 as shown by the arrow LA, The light is reflected by the reflective layer 8a, passes through the liquid crystal layer 50 again, and is emitted as reflective display light from the side of the counter substrate 20 to display an image (reflection mode).

Here, if the directionality of the light reflected by the light reflecting film 8a is strong, the viewing angle dependency such as the difference in brightness depending on the angle at which the image is viewed becomes noticeable. Therefore, when manufacturing a liquid crystal device, after applying a photosensitive resin such as an acrylic resin to a thickness of 800 nm to 1500 nm on the surface of the interlayer insulating film 4 or a surface protective film (not shown) formed on the surface thereof, By using the photolithography technique, the unevenness forming layer 13a made of a photosensitive resin layer is selectively left on the lower layer side of the light reflection film 8a in a predetermined pattern, so that the surface of the light reflection film 8a can be used for light scattering. The uneven pattern 8g is provided. Further, if left as it is, the edge of the unevenness forming layer 13a is left as it is in the unevenness pattern 8g. Therefore, another layer, the upper insulating film 7a made of a highly fluid photosensitive resin layer, is applied to the upper layer of the unevenness forming layer 13a. By forming the concave-convex pattern 8g having no edge and having a smooth shape on the surface of the light-reflecting film 8a. Alternatively, the unevenness forming layer 13a may be heated and melted to erase the edge.

In such a transflective liquid crystal device, if a color filter is formed on the counter substrate 20,
Although color display can be performed in both the transmissive mode and the reflective mode, the transmissive display light LB is emitted after passing through the color filter only once, whereas the reflective display light LA is emitted through the color filter. It will pass once. Therefore, in the reflective display region 100b in which the light reflective film 8a is formed on the counter substrate 20, the reflective display color filter 242 having a narrow chromaticity region is formed, while the transmissive window 8d is formed. Transparent display area 100c
A transmission display color filter 242 having a wide chromaticity region is formed on the display.

The reflective display color filter 242,
And on the upper layer side of the transmissive display color filter 242,
Transparent flattening film 26, counter electrode 21, and alignment film 22
Are formed in this order.

The size of the pixel 100a having such a structure is conventionally 60 μm × 180 μm, for example, and the concavo-convex forming layer 1 selectively left by the photolithography technique is used.
3a has a height and a width of 0.5 μ, respectively.
m and 7 μm to 10 μm, and the unevenness forming layer 13 a
The interval between them is 2 μm to 5 μm.

As such a structure, for example, the technique described in Japanese Patent Laid-Open No. 06-294906 is known.

[0013]

However, as the liquid crystal device is required to have a high definition display, the size of the pixel 100a tends to be further reduced. It is becoming difficult to impart scattering properties to display light. For example, in a 300 ppi liquid crystal device, the size of the pixel 100a is 25 μm × 75 μm.
Therefore, the unevenness forming layer 13a formed by the photolithography technique has a problem that each one is large and only a few can be formed in one pixel as in the conventional case due to the limitation of the exposure accuracy and the like. There is a point. Such a problem is more remarkable in a high-definition liquid crystal device of 300 ppi or more.

Further, in the transflective liquid crystal device, the transmissive display light passes through the liquid crystal layer 50 only once and is emitted, whereas the reflective display light passes through the liquid crystal layer 50 twice. Therefore, it is difficult to optimize the retardation Δn · d for both the transmitted display light and the reflected display light. Therefore, when the layer thickness d of the liquid crystal layer 50 is set so that the display in the reflective mode has good visibility, the display in the transmissive mode is sacrificed, while the display in the transmissive mode has good visibility. If the layer thickness d of the liquid crystal layer 50 is set so as to satisfy the above condition, there is a problem that the display in the reflection mode is sacrificed.

In view of the above problems, the object of the present invention is to
An object of the present invention is to provide a liquid crystal device capable of imparting a scattering property to reflected display light even if the pixel size is reduced, and an electronic device using the liquid crystal device.

Another object of the present invention is to provide a liquid crystal device capable of optimizing the retardation of the liquid crystal layer in both the transmissive display region and the reflective display region, and an electronic device using the liquid crystal device. .

[0017]

In order to solve the above problems, according to the present invention, a first transparent substrate on which first transparent electrodes are formed in a matrix and a second transparent electrode are formed on the surface. A second transparent substrate, a liquid crystal layer held between the first transparent substrate and the second transparent substrate, and at least one of the pixels in the pixel is provided on the first transparent substrate side. In a liquid crystal device in which a light reflection layer having a portion as a reflection display region is formed, the second transparent substrate has a light scattering layer containing light scattering particles in at least a region facing the reflection display region. It is characterized by

In the present invention, since the light-scattering layer formed on the second transparent substrate imparts the scattering property to the reflected display light, the concavo-convex forming layer is formed on the first transparent substrate side by the photolithography technique. No need. Further, with the light scattering layer using light scattering particles, it is possible to impart the scattering property to the reflection display light even if the size of the pixel is reduced.

In the present invention, for example, in the pixel,
A pixel switching element that controls the first transparent electrode is formed.

In the present invention, it is preferable that the light reflection layer is formed in a part of the pixel so that the remaining area in the pixel is a transmissive display area. With this configuration, it is possible to configure a transflective liquid crystal device capable of displaying an image in both the reflective mode and the transmissive mode.

With this structure, a color filter for transmissive display is formed in the transmissive display area on the second transparent substrate, and a color filter for transmissive display is formed in the reflective display area.
It is preferable that a reflective display color filter having a narrower chromaticity range than the transmissive display color filter is formed. In the present specification, "wide chromaticity range" means that the area of a color triangle represented by, for example, the CIE1931 rgb colorimetric chromaticity diagram is large, and corresponds to a dark hue. According to this structure, the transmissive display light passes through the color filter only once and is emitted, whereas the reflective display light passes through the color filter twice. The same color tone can be obtained in the display area.

In the present invention, a transparent flat film may be formed on the second transparent substrate on the front surface side of the transmissive display color filter and the transmissive display color filter. In such a case, it is preferable that the flat film includes the light-scattering particles to give a function as the light-scattering layer. With this configuration,
The scattering property can be imparted to the reflected display light without adding a new layer.

In the present invention, the reflective display color filter may contain the light scattering particles to impart a function as the light scattering layer. According to this structure, the reflective display light can be provided with the scattering property without adding a new layer.

In the present invention, since the reflective display color filter is formed thicker than the transmissive display color filter, the liquid crystal layer in the reflective display region has a layer thickness of the liquid crystal in the transmissive display region. It is preferably thinner than the layer thickness. According to this structure, the layer thickness of the liquid crystal layer in the reflective display region can be made smaller than the layer thickness of the liquid crystal layer in the transmissive display region without adding a new layer. Therefore, the transmitted display light passes through the liquid crystal layer only once and is emitted, whereas the reflected display light passes through the liquid crystal layer twice, but the transmitted display light and the reflected display light are transmitted. In both cases, the retardation Δn · d can be optimized.

In the present invention, the layer thickness of the liquid crystal layer in the reflective display region is set to the liquid crystal in the transmissive display region on the surface side of at least one of the first transparent substrate and the second transparent substrate. It is preferable that a layer thickness adjusting layer that is thinner than the layer thickness is formed. According to this structure, since the layer thickness of the liquid crystal layer in the reflective display region can be made smaller than that of the liquid crystal layer in the transmissive display region, the transmissive display light is emitted after passing through the liquid crystal layer only once. Thus, even if the reflection display light passes through the liquid crystal layer twice, the retardation Δn · d can be optimized for both the transmission display light and the reflection display light.

In the present invention, the layer thickness adjusting layer is a transparent layer selectively formed in a region overlapping with the reflective display color filter, and includes the light scattering particles as the light scattering layer. It is preferable to have the function of. According to this structure, the reflective display light can be provided with the scattering property without adding a new layer. Further, if the layer thickness adjusting layer is formed on the second transparent substrate, even if the layer thickness adjusting layer is provided, the exposure accuracy in the photolithography process for forming the pixel switching element on the first transparent substrate is improved. Does not decrease. Therefore, it is possible to provide a transflective liquid crystal device having high reliability and high display quality.

In the present invention, at least one of the first transparent substrate and the second transparent substrate is provided with a surface of at least one of the first transparent substrate by projecting from one substrate and abutting the other substrate. It is preferable that columnar protrusions that define a substrate distance between the substrate and the second transparent substrate are formed. Depending on the thickness balance of the color filter or the formation of the layer thickness adjusting layer, the first transparent substrate side or the second transparent substrate side is formed.
Even if irregularities are formed on the transparent substrate side, it is not necessary to disperse the gap material if the substrate spacing is controlled by the columnar protrusions formed on the first transparent substrate side or the second transparent substrate side. Therefore, between the plate of the first transparent base material and the second transparent substrate, the gap of the substrate is varied due to the gap material rolling into the concave portion of the unevenness caused by the layer thickness adjusting layer. Does not occur, and the retardation Δn · d can be maintained in an optimum state. Therefore, high-quality display can be performed.

The liquid crystal device to which the present invention is applied can be used as a display device for electronic devices such as mobile phones and mobile computers.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. In each figure used in the following description,
In order to make each layer and each member recognizable in the drawing, the scale is different for each layer and each member.

[First Embodiment] (Basic Structure of Transflective Liquid Crystal Device) FIG. 1 is a plan view of a transflective liquid crystal device to which the present invention is applied as viewed from the counter substrate side together with each component. FIG. 2 is a sectional view taken along line HH ′ in FIG. 1. FIG. 3 is an equivalent circuit diagram of various elements, wirings, etc. in a plurality of pixels formed in a matrix in the image display area of the transflective liquid crystal device.
In each of the drawings used to describe the present embodiment, the scale of each layer and each member is different in order to make each layer and each member recognizable in the drawing.

1 and 2, the semi-transmissive reflective liquid crystal device 100 of this embodiment has a TFT array substrate 10 (first transparent substrate) and a counter substrate 20 (second transparent substrate) which are bonded together by a sealing material 52. ), A liquid crystal layer 50 as an electro-optical material is held, and a peripheral partition 53 made of a light-shielding material is formed in an area inside the area where the sealing material 52 is formed. A data line driving circuit 101 and a mounting terminal 102 are formed along an edge of the TFT array substrate 10 in a region outside the sealing material 52.
The scanning line driving circuit 104 is provided along two sides adjacent to this one side.
Are formed. On the remaining one side of the TFT array substrate 10, the scanning line driving circuit 1 provided on both sides of the image display area
A plurality of wirings 105 for connecting the terminals 04 are provided, and further, a precharge circuit or a test circuit may be provided under the peripheral partition 53. Further, at least one position of the corner portion of the counter substrate 20 is formed with a vertical conductive material 106 for electrically connecting the TFT array substrate 10 and the counter substrate 20. Further, the data line driving circuit 101, the scanning line driving circuit 104, and the like may overlap with the sealing material 52 or may be formed in the inner region of the sealing material 52.

Instead of forming the data line driving circuit 101 and the scanning line driving circuit 104 on the TFT array substrate 10, for example, a TA on which a driving LSI is mounted is mounted.
A B (tape automated, bonding) substrate may be electrically and mechanically connected to a terminal group formed on the periphery of the TFT array substrate 10 via an anisotropic conductive film. In addition, the transflective liquid crystal device 10
0 indicates the type of liquid crystal layer 50 used, that is, TN.
A polarizing film, a retardation film, a polarizing plate, etc. are arranged in a predetermined direction according to an operation mode such as (twisted nematic) mode, STN (super TN) mode, etc., and normally white mode / normally black mode. However, illustration is omitted here.

Further, the transflective liquid crystal device 10 of the present embodiment
Since 0 is for color display, color filters of R, G, and B colors are formed in regions of the counter substrate 20 facing the pixel electrodes 9a of the TFT array substrate 10, as described later. .

In the image display area 10a of the transflective liquid crystal device 100 having the above structure, a plurality of pixels 100a are arranged in a matrix as shown in FIG. 3, and each of the pixels 100a is formed. Is formed with a pixel electrode 9a and a pixel switching TFT 30 for driving the pixel electrode 9a, and a data line 6a for supplying pixel signals S1, S2 ... Sn is electrically connected to the source of the TFT 30. Connected to each other. The pixel signals S1, S2 ... Sn to be written to the data line 6a are
The data may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a. Further, the scanning line 3a is electrically connected to the gate of the TFT 30, and the scanning signals G1, G2 ... Are pulsed to the scanning line 3a at a predetermined timing.
Gm is line-sequentially applied in this order. The pixel electrode 9a is electrically connected to the drain of the TFT 30, and the pixel signal S1, S2 ... Sn supplied from the data line 6a is generated by turning on the TFT 30 which is a switching element for a certain period. Is written in each pixel at a predetermined timing. The predetermined level pixel signals S1, S2, ... Sn written in the liquid crystal through the pixel electrode 9a in this manner are held for a certain period between the pixel signal S1, S2, ... Sn and the counter electrode 21 of the counter substrate 20 shown in FIG. .

Here, the liquid crystal layer 50 modulates light by changing the orientation and order of the molecular assembly depending on the applied voltage level, and enables gradation display. In the normally white mode, the amount of incident light passing through the portion of the liquid crystal layer 50 decreases depending on the applied voltage, and in the normally black mode, the incident light changes depending on the applied voltage. The amount of light passing through this liquid crystal layer 50 increases. As a result, the light having the contrast according to the pixel signals S1, S2, ... Sn is emitted from the transflective liquid crystal device 100 as a whole.

The pixel signals S1, S2, ...
.. In order to prevent Sn from leaking, the storage capacitor 60 may be added in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode. For example, the voltage of the pixel electrode 9a is held by the storage capacitor 60 for a time that is three orders of magnitude longer than the time when the source voltage is applied. As a result, the charge retention characteristic is improved, and the transflective liquid crystal device 100 having a high contrast ratio can be realized. In addition, storage capacity 6
As a method of forming 0, as illustrated in FIG. 3, it is formed between the storage line 60 and the capacitance line 3b, which is a wiring for forming the storage capacitance 60, or between the scan line 3a of the preceding stage. Either case may be used.

(Structure of TFT Array Substrate) FIG. 4 is a plan view of a plurality of pixel groups adjacent to each other on the TFT array substrate used in the transflective liquid crystal device of this embodiment. FIG. 5 is a cross-sectional view of a portion of a pixel formed in the transflective liquid crystal device of this embodiment, taken along a line corresponding to the line CC 'in FIG.

In FIG. 4, a plurality of transparent ITO (Indium Tin Ox) are formed on the TFT array substrate 10.
pixel electrodes 9a (first transparent electrodes) formed of a (ide) film are formed in a matrix, and each of the pixel electrodes 9a is formed.
The pixel switching TFTs 30 are respectively connected to the. Further, the data line 6a, the scanning line 3a, and the capacitance line 3b are formed along the vertical and horizontal boundaries of the pixel electrode 9a, and the TFT 30 includes the data line 6a and the scanning line 3a.
Connected to. That is, the data line 6a is electrically connected to the high-concentration source region 1d of the TFT 30 through the contact hole, and the protruding portion of the scanning line 3a constitutes the gate electrode of the TFT 30. The storage capacitor 60 has a structure in which an extended portion 1f of the semiconductor film 1 for forming the pixel switching TFT 30 is made into a conductive lower electrode, and the lower electrode 41 is overlapped with the capacitive line 3b as an upper electrode. It has become.

The C- of the pixel 100a thus constructed
As shown in FIG. 5, the cross section taken along the line C ′ is a silicon oxide film (insulating film) having a thickness of 300 nm to 500 nm on the surface of the transparent substrate 10 ′ which is the base of the TFT array substrate 10.
The underlayer protective film 11 is formed, and the underlayer protective film 1 is formed.
On the surface of No. 1, an island-shaped semiconductor film 1a having a thickness of 30 nm to 100 nm is formed. A gate insulating film 2 made of a silicon oxide film having a thickness of about 50 to 150 nm is formed on the surface of the semiconductor film 1a, and a scanning line 3a having a thickness of 300 nm to 800 nm is formed on the surface of the gate insulating film 2. Has been done. A region of the semiconductor film 1a facing the scanning line 3a via the gate insulating film 2 is a channel region 1a '. A source region including a low concentration source region 1b and a high concentration source region 1d is formed on one side of the channel region 1a ', and a drain including a low concentration drain region 1c and a high concentration drain region 1e is formed on the other side. A region is formed.

An interlayer insulating film 4 made of a silicon oxide film having a thickness of 300 nm to 800 nm is formed on the surface side of the pixel switching TFT 30, and a silicon nitride film or a silicon oxide film is formed on the surface of the interlayer insulating film 4. An interlayer insulating film 7 made of a film is formed. A data line 6a having a thickness of 300 nm to 800 nm is formed on the surface of the interlayer insulating film 4, and the data line 6a is electrically connected to the high concentration source region 1d through a contact hole formed in the interlayer insulating film 4. Connected to. A drain electrode 6b formed simultaneously with the data line 6a is formed on the surface of the interlayer insulating film 4, and the drain electrode 6b is electrically connected to the high-concentration drain region 1e through a contact hole formed in the interlayer insulating film 4. Connected to.

On the upper layer of the interlayer insulating film 7, a light reflecting film 8a made of an aluminum film or the like is formed. As shown in FIGS. 4 and 5, the light reflection layer 8a is formed only on one short side of the pair of short sides of the substantially rectangular pixel 100a, and the other short side is formed on the light reflection layer 8a. It is a light transmission window 8d in which is not formed. Therefore, in the substantially rectangular pixel 100a, one short side on which the light reflection layer 8a is formed is the reflection display area 100b, and the light transmission window 8 is formed.
The other short side, which is d, is the transmissive display area 100c.
It has become. In other words, the boundary portion 27 between the transmissive display area 100c and the reflective display area 100b is the pixel 100.
In a, the transmissive display region 100 extends linearly in parallel with the short side.
The three sides of c overlap with the three sides of the pixel 100a.

In this embodiment, the concavo-convex forming layer 13a described with reference to FIGS. 11 and 12 is not formed on the lower layer side of the light reflecting layer 8a, and the surface of the light reflecting layer 8a is generally flat. is there.

Referring again to FIG. 5, a pixel electrode 9a made of an ITO film is formed on the light reflection film 8a. The pixel electrode 9a is directly laminated on the surface of the light reflection film 8a,
The pixel electrode 9a and the light reflection film 8a are electrically connected. The pixel electrode 9a is electrically connected to the drain electrode 6b through a contact hole formed in the photosensitive resin layer 7a and the interlayer insulating film 4.

An alignment film 12 made of a polyimide film is formed on the surface side of the pixel electrode 9a. This alignment film 12
Is a film obtained by rubbing a polyimide film.

For the extended portion 1f (lower electrode) extending from the high-concentration drain region 1e, the capacitance line 3b is connected to the upper electrode via an insulating film (dielectric film) formed simultaneously with the gate insulating film 2. The storage capacitors 60 are formed by facing each other.

The TFT 30 preferably has the LDD structure as described above, but has the offset structure in which the impurity ions are not implanted into the regions corresponding to the low concentration source region 1b and the low concentration drain region 1c. May be. Further, the TFT 30 may be a self-alignment type TFT in which high-concentration source and drain regions are formed in a self-aligned manner by implanting high-concentration impurity ions using the gate electrode (a part of the scanning line 3a) as a mask. .

Further, in the present embodiment, the single gate structure in which only one gate electrode (scanning line 3a) of the TFT 30 is arranged between the source and drain regions is used, but two or more gate electrodes are arranged between them. You may. At this time, the same signal is applied to each gate electrode.
By configuring the TFT 30 with a dual gate (double gate) or a triple gate or more in this way, it is possible to prevent a leak current at the junction between the channel and the source-drain region, and reduce the off-time current. If at least one of these gate electrodes has an LDD structure or an offset structure, the off current can be further reduced, and a stable switching element can be obtained.

The TFT array substrate 10 and the counter substrate 2
0 means that the gap between the substrates is defined by the gap material 5 scattered on one of the substrates.

(Structure of Counter Substrate) In the present embodiment, the counter substrate 20 is referred to as a black matrix or a black stripe in a region facing the vertical and horizontal boundaries of the pixel electrodes 9a formed on the TFT array substrate 10. A light shielding film 23 is formed, and ITO is formed on the upper layer side.
A counter electrode 21 (second electrode) made of a film is formed. An alignment film 22 made of a polyimide film is formed on the upper layer side of the counter electrode 21, and the alignment film 22 is a film obtained by rubbing the polyimide film.

On the front surface side of the counter substrate 20, the counter electrode 2
R on the lower layer side of 1 in the region facing the pixel electrode 9a,
The G and B color filters are formed to a thickness of 1 μm to several μm. However, in the transflective liquid crystal device 100,
When the display in the reflective mode and the display in the transmissive mode are performed, the transmissive display light passes through the color filter only once and is emitted, as shown by an arrow LB, while the reflective display light indicates the arrow. As shown by LA, two color filters are used.
It will pass once. Therefore, in this embodiment, in the reflective display region 100b of the surface of the counter substrate 20 where the light reflective film 8a is formed, the reflective display color filter 242 having a narrow chromaticity region is formed, while the transparent display color filter 242 is transmitted. Window 8d
In the transmissive display area 100c in which is formed, a transmissive display color filter 242 having a wide chromaticity region is formed.

On the counter substrate 20, the reflective display color filter 242 and the transmissive display color filter 2 are provided.
A flattening film 26 is formed on the surface side of 42.

Here, the flattening film 26 is a transparent resin layer such as an acrylic resin or a polyimide resin, but in this embodiment, the resin forming the flattening film 26 has an average particle diameter of, for example, 300 nm to 500 nm. The transparent light scattering particles 29 made of silicon fine particles, glass particles, or resin fine particles are included. Therefore, the flattening film 26 has a function of flattening the lower layer side of the counter electrode 21 and the flattening film 26.
It has a function as a light-scattering layer that imparts a light-scattering property to the light passing through.

In such a counter substrate 20, first, a light shielding film 23 is formed by using a photolithography technique, and then,
The reflective display color filter 242 and the transmissive display color filter 242 are formed by using a photolithography technique, a flexographic printing method, or an inkjet method, and then the flattening film 26, the counter electrode 21, and the alignment film 22 are formed. It can be manufactured by forming in this order.
At that time, the light-scattering particles 29 are mixed with the material for forming the flattening film 26.

(Operation / Effect of this Embodiment) In an electronic device equipped with the transflective liquid crystal device 100 having such a configuration,
While the display is performed in the reflection mode using the reflection display light indicated by the arrow LA during standby, the backlight is turned on during use and in addition to the reflection mode, the transmission mode using the transmission display light indicated by the arrow LB is used. Is also displayed.

At this time, the reflected display light is emitted while passing through the flattening film 26 while being scattered by the light scattering particles 29 contained therein. Therefore, it is not necessary to form irregularities on the side of the TFT array substrate 10 by using the photolithography technique, and if the layer includes the light scattering particles 29 (light scattering layer), the size of the pixel 100a is For example, even if it is as small as 25 μm or less × 75 μm or less, light scattering property can be imparted, so that it can be sufficiently applied to a liquid crystal device of 300 ppi, and further 400 ppi.

In this embodiment, since the flattening film 26 is used as the scattering layer, the light emitted from the transmissive display region 100c is also provided with the scattering property, but the display quality is not deteriorated.

[Second Embodiment] FIG. 6 shows a portion of a pixel formed in a transflective liquid crystal device according to a second embodiment of the present invention at a position corresponding to the line CC 'in FIG. It is sectional drawing when it cut | disconnects by. In this embodiment and any of the embodiments described below, the basic configuration is the same as that of the first embodiment. Therefore, common portions are given the same reference numerals and their description is omitted, and only the configuration of the counter substrate, which is a feature of each embodiment, will be described.

Referring to FIG. 6, in the present embodiment as well, the first embodiment
Similarly to the above, on the surface of the counter substrate 20, the reflective display region 1 in which the light reflection film 8a is formed on the TFT array substrate 10 is formed.
00b is a reflective display color filter 2 having a narrow chromaticity range.
On the other hand, a transparent display color filter 242 having a wide chromaticity range is formed in the transparent display area 100c in which the transparent window 8d is formed while the transparent display color filter 242 is formed. A transparent flattening film 26, a transparent counter electrode 21, and an alignment film 22 are formed in this order on the surface side of the reflective display color filter 242 and the transmissive display color filter 242.

In the present embodiment, the reflective display color filter 242 has an average particle size of, for example, 300 in addition to various coloring materials.
As a light scattering layer that mixes transparent light scattering particles 29 made of silicon fine particles, glass particles, or resin fine particles having a size of 500 nm to 500 nm to color reflected display light and impart light scattering property to the reflected display light. Function.

Also on the counter substrate 20 as described above, after the light shielding film 23 is formed by using the photolithography technique, the reflection display color filter 24 is formed by using the photolithography technique, the flexographic printing method, or the ink jet method.
2, and a color filter 242 for transmissive display is formed,
After that, the flattening film 26, the counter electrode 21, and the alignment film 22 are formed in this order to manufacture. At that time, the light-scattering particles 29 are mixed in the material for forming the reflective display color filter 242. Here, the pigment itself contained in the reflective display color filter 242 may be used as the light scattering particles 29.

A transflective liquid crystal device 1 having such a configuration
00, the reflective display light is reflected by the color filter 2 for reflective display.
When passing through 42, the light scattering particles 29 contained therein
It is emitted while being scattered by. Therefore, it is not necessary to form irregularities on the side of the TFT array substrate 10 by using the photolithography technique, and if the layer includes the light scattering particles 29 (light scattering layer), the light scattering particles 29 The reflective display color filter 242 (light-scattering layer) including the can be easily formed in a region corresponding to the size of the pixel 100a.

[Third Embodiment] FIG. 7 shows a portion of a pixel formed in a transflective liquid crystal device according to a third embodiment of the present invention at a position corresponding to the line CC 'in FIG. It is sectional drawing when it cut | disconnects by.

Referring to FIG. 7, in this embodiment also, the first embodiment
Similarly to the above, on the surface of the counter substrate 20, the reflective display region 1 in which the light reflection film 8a is formed on the TFT array substrate 10 is formed.
00b is a reflective display color filter 2 having a narrow chromaticity range.
On the other hand, a transparent display color filter 242 having a wide chromaticity range is formed in the transparent display area 100c in which the transparent window 8d is formed while the transparent display color filter 242 is formed. A transparent counter electrode 21 and an alignment film 22 are formed in this order on the surface side of the reflective display color filter 242 and the transmissive display color filter 242.

In the present embodiment, the reflective display color filter 242 contains various color materials and fine light-scattering particles for coloring the reflective display light and providing the reflective display light with a light-scattering property. It functions as an applied light scattering layer.

Here, the reflective display color filter 242.
In comparison with the transmissive display color filter 241, a thick color material having a narrow chromaticity range is used, and a flattening film is not formed on the surface side thereof. Therefore, the reflective display area 10
The layer thickness d of the liquid crystal layer 50 at 0b is
It is considerably thinner than the layer thickness d of the liquid crystal layer 50 at 0c.

Further, in this embodiment, the TFT array substrate 1
The space between the TFT array substrate 10 and the counter substrate 20 is defined by the columnar protrusions 40 formed at 0, and the gap material is not scattered between the TFT array substrate 10 and the counter substrate 20.

Also on the counter substrate 20 as described above, after the light shielding film 23 is formed by using the photolithography technique, the reflection display color filter 24 is formed by using the photolithography technique, the flexographic printing method or the ink jet method.
2, and a color filter 242 for transmissive display is formed,
After that, the counter electrode 21 and the alignment film 22 are formed in this order, and thus it can be manufactured. At that time, the light-scattering particles 29 are mixed in the material for forming the reflective display color filter 242, and the transmissive display color filter 24 is used as the reflective display color filter 242.
It is formed thicker than No. 1.

The transflective liquid crystal device 1 having such a configuration
00, the reflective display light is reflected by the color filter 2 for reflective display.
When passing through 42, the light scattering particles 29 contained therein
It is emitted while being scattered by. Therefore, it is not necessary to form irregularities on the side of the TFT array substrate 10 by using the photolithography technique, and if the layer includes the light scattering particles 29 (light scattering layer), the light scattering particles 29 The reflective display color filter 242 (light-scattering layer) including the can be easily formed in a region corresponding to the size of the pixel 100a.

Further, in this embodiment, the thicknesses of the transmissive display color filter 241 and the reflective display color filter 242 are changed so that the layer thickness d of the liquid crystal layer 50 in the reflective display area 100b is changed to the liquid crystal layer in the transmissive display area 100c. It is considerably thinner than the layer thickness d of 50. Therefore, while the transmissive display light passes through the liquid crystal layer 50 only once and is emitted, the reflective display light passes through the liquid crystal layer 50 twice, but in the present embodiment, the transmissive display light is transmitted. Since the retardation Δn · d can be optimized for both the reflection display light and the reflected display light, high-quality display can be performed.

Further, the columnar protrusions 40 formed on the TFT array substrate 10 define the distance between the TFT array substrate 10 and the counter substrate 20, and the gap material is dispersed between the TFT array substrate 10 and the counter substrate 20. Therefore, even if the counter substrate 20 has unevenness due to the layer thickness adjusting layer 25, the problem that the gap material does not function because it is accumulated in the recess does not occur. Therefore, the TFT array substrate 1
Since the interval between 0 and the counter substrate 20 is accurately defined and the retardation Δn · d is optimized, high-quality display can be performed.

[Fourth Embodiment] FIG. 8 shows a portion of a pixel formed in the transflective liquid crystal device according to the fourth embodiment of the present invention at a position corresponding to the line CC 'in FIG. It is sectional drawing when it cut | disconnects by.

Referring to FIG. 7, in the present embodiment as well, the first embodiment
Similarly to the above, on the surface of the counter substrate 20, the reflective display region 1 in which the light reflection film 8a is formed on the TFT array substrate 10 is formed.
00b is a reflective display color filter 2 having a narrow chromaticity range.
On the other hand, a transparent display color filter 242 having a wide chromaticity range is formed in the transparent display area 100c in which the transparent window 8d is formed while the transparent display color filter 242 is formed. A transparent counter electrode 21 and an alignment film 22 are formed in this order on the surface side of the reflective display color filter 242 and the transmissive display color filter 242.

Further, in this embodiment, on the surface of the counter substrate 20, the reflective display color filter 242 and the counter electrode 21 are provided.
A layer thickness adjusting layer 25 made of a transparent resin layer such as an acrylic resin or a polyimide resin is formed between the layers and with a thickness of 2 μm to 4 μm. Therefore, the layer thickness d of the liquid crystal layer 50 in the reflective display area 100b is smaller than the layer thickness d of the liquid crystal layer 50 in the transmissive display area 100c. Here, the end portion 250 of the layer thickness adjusting layer 25 has a tapered surface, but such a tapered end portion 250 has a reflective display region 100.
It is located within b.

Further, in this embodiment, the TFT array substrate 1
Columnar protrusion 40 having a height of 2 μm to 3 μm
Thus, the gap between the TFT array substrate 10 and the counter substrate 20 is defined, and the gap material is not dispersed between the TFT array substrate 10 and the counter substrate 20.

Here, the layer thickness adjusting layer 25 is a transparent resin layer such as an acrylic resin or a polyimide resin, but in this embodiment, the resin constituting the layer thickness adjusting layer 25 has an average particle diameter of, for example, 300 nm. Transparent light-scattering particles 29 made of silicon fine particles, glass particles, or resin fine particles having a size of up to 500 nm are included. Therefore, the layer thickness adjusting layer 25 has a function of adjusting the layer thickness d of the liquid crystal layer 50 and a function as a light scattering layer that imparts a light scattering property to the light transmitted through the layer thickness adjusting layer 25. There is.

In such a counter substrate 20, first, a light shielding film 23 is formed by using a photolithography technique, and then,
The reflective display color filter 242 and the transmissive display color filter 242 are formed by using a photolithography technique, a flexographic printing method, or an inkjet method, and thereafter, the layer thickness adjusting layer 25, the counter electrode 21, and the alignment film 22. Can be manufactured in this order. At that time, the light-scattering particles 29 are blended with the material for forming the layer thickness adjusting layer 5.

The transflective liquid crystal device 1 having such a configuration
In 00, the reflected display light is emitted while passing through the layer thickness adjusting layer 25 while being scattered by the light scattering particles 29 contained therein. Therefore, it is not necessary to form irregularities on the side of the TFT array substrate 10 by using the photolithography technique, and if the layer thickness adjusting layer 25 (light scattering layer) containing the light scattering particles 29 is used, the pixel 100a can be formed. Can be easily formed in a region corresponding to the size of the.

In this embodiment, the layer thickness adjusting layer 25 is provided on the counter substrate 20 side so that the layer thickness d of the liquid crystal layer 50 in the reflective display area 100b is smaller than the layer thickness d of the liquid crystal layer 50 in the transmissive display area 100c. Is also quite thin. Therefore,
Since the retardation Δn · d can be optimized for both the transmissive display light and the reflective display light, high-quality display can be performed.

Moreover, in the present embodiment, the end portion 250 of the layer thickness adjusting layer 25 has a tapered surface, and the proper value of the layer thickness of the liquid crystal layer 50 deviates there.
Is located in the reflective display region 100b, such a deviation in layer thickness does not affect the image quality when displaying in the transmissive mode.

Further, the layer thickness adjusting layer 25 is formed on the counter substrate 20 side, that is, the substrate on which the pixel switching TFT 30 is not formed, and the reflective display region 100 is formed.
The thickness d of the liquid crystal layer 50 in FIG.
The thickness is smaller than the layer thickness d of the liquid crystal layer 50 in FIG. Therefore, even if the layer thickness adjusting layer 25 is provided, the TFT array substrate 1
The exposure accuracy does not decrease in the photolithography process for forming the TFT 30 on the substrate. Therefore, the transflective liquid crystal device 100 having high reliability and high display quality is provided.
Can be provided.

Further, the columnar protrusions 40 formed on the TFT array substrate 10 define the distance between the TFT array substrate 10 and the counter substrate 20, and the gap material is scattered between the TFT array substrate 10 and the counter substrate 20. Therefore, even if the counter substrate 20 has unevenness due to the layer thickness adjusting layer 25, the problem that the gap material does not function because it is accumulated in the recess does not occur. Therefore, the TFT array substrate 1
Since the interval between 0 and the counter substrate 20 is accurately defined and the retardation Δn · d is optimized, high-quality display can be performed.

[Other Embodiments] The present invention has been described so far by taking the transflective liquid crystal device as an example, but the present invention can be similarly applied to the reflective liquid crystal device.

In the third and fourth embodiments, the counter substrate 2 is used.
An example in which the substrate spacing is controlled by the columnar protrusions 40 in the liquid crystal device in which the layer thickness adjusting layer 25 is formed in 0 has been described, but in the liquid crystal device in which the layer thickness adjusting layer 25 is formed in the TFT array plate 10, Then, the substrate spacing may be controlled by the columnar protrusion 40.

Further, the columnar protrusions 40 may be formed on the counter substrate 20 side.

Furthermore, in the above-described embodiment, an example in which a TFT is used as an active element for pixel switching has been described, but an MIM (Metal I) is used as an active element.
thin film diode element (TFD element / Thin Film Diode)
The same applies when an e element) is used.

[Application of transflective liquid crystal device to electronic equipment] The transflective liquid crystal device 100 configured as described above.
Can be used as a display portion of various electronic devices, and an example thereof will be described with reference to FIGS. 9, 10A, and 10B.

FIG. 9 is a block diagram showing a circuit configuration of an electronic device using the transflective liquid crystal device according to the present invention as a display device.

In FIG. 9, the electronic equipment has a display information output source 70, a display information processing circuit 71, a power supply circuit 72, a timing generator 73, and a liquid crystal device 74.
The liquid crystal device 74 also includes a liquid crystal display panel 75 and a drive circuit 76. As the liquid crystal device 74, the transflective liquid crystal device 100 described above can be used.

The display information output source 70 is a ROM (Read
Only Memory), RAM (Random)
A memory such as an Access Memory), a storage unit such as various disks, a tuning circuit that tunes and outputs a digital image signal, and the like, and a display such as an image signal of a predetermined format based on various clock signals generated by the timing generator 73. Information is supplied to the display information processing circuit 71.

The display information processing circuit 71 includes various well-known circuits such as a serial-parallel conversion circuit, an amplification / inversion circuit, a rotation circuit, a gamma correction circuit, and a clamp circuit, and executes processing of input display information. , And supplies the image signal to the drive circuit 76 together with the clock signal CLK. The power supply circuit 72 supplies a predetermined voltage to each component.

FIG. 10A shows a mobile personal computer which is an embodiment of the electronic apparatus according to the present invention. Personal computer 80 shown here
Has a main body portion 82 having a keyboard 81 and a liquid crystal display unit 83. The liquid crystal display unit 83 includes the transflective liquid crystal device 100 described above.

FIG. 10B shows a portable telephone which is another embodiment of the electronic apparatus according to the present invention. The mobile phone 90 shown here has a plurality of operation buttons 91 and a display unit including the above-described transflective liquid crystal device 100.

[0093]

As described above, according to the present invention, the second
Since the light-scattering layer formed on the transparent substrate imparts the scattering property to the reflected display light, it is not necessary to form the unevenness forming layer on the first transparent substrate side by the photolithography technique. Further, with the light scattering layer using light scattering particles, it is possible to impart the scattering property to the reflection display light even if the size of the pixel is reduced.

[Brief description of drawings]

FIG. 1 is a plan view of a transflective liquid crystal device to which the present invention is applied, as viewed from a counter substrate side.

FIG. 2 is a sectional view taken along the line HH ′ of FIG.

FIG. 3 is an equivalent circuit diagram of elements and the like formed in a plurality of pixels in a matrix in a transflective liquid crystal device.

FIG. 4 is a plan view showing a configuration of each pixel of the TFT array substrate of the transflective liquid crystal device according to the present invention.

5 is a cross-sectional view of a portion of a pixel formed in the transflective liquid crystal device according to Embodiment 1 of the present invention, taken along a line corresponding to the line CC 'in FIG. .

FIG. 6 is a cross-sectional view of a portion of a pixel formed in the transflective liquid crystal device according to Embodiment 2 of the present invention when cut at a position corresponding to line CC ′ in FIG. 4. .

FIG. 7 is a cross-sectional view of a portion of a pixel formed in the transflective liquid crystal device according to Embodiment 3 of the present invention, taken along a line corresponding to the line CC ′ in FIG. 4. .

FIG. 8 is a cross-sectional view of a portion of a pixel formed in the transflective liquid crystal device according to Embodiment 4 of the present invention, taken along a line corresponding to the line CC ′ in FIG. 4; .

FIG. 9 is a block diagram showing a circuit configuration of an electronic device using the transflective liquid crystal device according to the present invention as a display device.

10A and 10B are explanatory views of a mobile personal computer and a mobile phone using the transflective liquid crystal device according to the present invention, respectively.

FIG. 11 is an explanatory diagram schematically showing a state in which a pixel is provided with a reflective display region and a transmissive display region in a conventional transflective liquid crystal device.

12 is a cross-sectional view of a portion of a pixel formed in the transflective liquid crystal device shown in FIG. 11, taken along a line corresponding to the line DD ′ in FIG.

[Explanation of symbols]

1a Semiconductor film 2 Gate insulating film 3a scanning line 3b Capacitance line 4, 7 Interlayer insulation film 6a data line 6b drain electrode 8a Light reflection film 8d light transmission window 9a Pixel electrode 10 TFT array substrate 20 Counter substrate 21 Counter electrode 23 Light-shielding film 25 layer thickness adjustment layer 26 Flattening film 29 Light scattering particles 30 pixel switching TFT 40 columnar protrusion 50 liquid crystal layer 60 storage capacity 100 transflective liquid crystal device 100a pixel 100b reflective display area 100c transparent display area 241 Color filter for transmissive display 242 Color filter for reflective display

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) G02F 1/1343 G02F 1/1343 F Term (Reference) 2H089 HA07 LA09 LA12 TA02 TA09 TA17 2H090 HA04 HA08 HB08X HB13X HD06 LA01 LA02 LA10 LA15 LA20 2H091 FA02Y FA15Y FA16Y FD04 FD06 FD23 FD24 GA02 GA07 GA08 GA13 GA16 LA13 LA16 2H092 GA13 GA23 PA03 PA08 PA12

Claims (11)

[Claims] 1. A first transparent substrate on which first transparent electrodes are formed in a matrix, a second transparent substrate on which second transparent electrodes are formed, the first transparent substrate, and the second transparent substrate. A liquid crystal layer held between the transparent substrate and the liquid crystal layer, wherein a light reflection layer having a reflective display region in at least a part of the pixel is formed on the first transparent substrate side. The liquid crystal device, wherein the second transparent substrate has a light scattering layer containing light scattering particles in at least a region facing the reflective display region. 2. The liquid crystal device according to claim 1, wherein a pixel switching element that controls the first transparent electrode is formed in the pixel. 3. The light reflection layer according to claim 1, wherein the light reflection layer is formed in a part of the pixel,
A liquid crystal device, wherein the remaining area in the pixel is a transmissive display area. 4. The transmissive display color filter is formed in the transmissive display area on the second transparent substrate, and the transmissive display color filter is formed in the reflective display area. A liquid crystal device characterized in that a reflective display color filter having a narrow chromaticity region is formed. 5. The transparent flat film according to claim 4, wherein a transparent flat film is formed on the surface side of the transmissive display color filter and the transmissive display color filter, and the flat film is formed of the transparent film. A liquid crystal device comprising light scattering particles and also having a function as the light scattering layer. 6. The liquid crystal device according to claim 4, wherein the reflective display color filter includes the light scattering particles and also has a function as the light scattering layer. 7. The reflective display color filter according to claim 6, wherein the reflective display color filter is formed to be thicker than the transmissive display color filter. The liquid crystal device is thinner than the layer thickness of the liquid crystal layer in. 8. The method according to claim 3, wherein
On at least one surface side of the first transparent substrate and the second transparent substrate, the layer thickness of the liquid crystal layer in the reflective display region is thinner than the layer thickness of the liquid crystal layer in the transmissive display region. A liquid crystal device having a layer thickness adjusting layer formed thereon. 9. The layer thickness adjusting layer according to claim 8,
A liquid crystal device, which is a transparent layer selectively formed in a region overlapping with the reflective display color filter, and which also includes the light scattering particles and also has a function as the light scattering layer. 10. The method according to any one of claims 1 to 9,
At least one surface side of the first transparent substrate and the second transparent substrate is projected from one substrate and brought into contact with the other substrate so as to contact the first transparent substrate and the second transparent substrate. A liquid crystal device having columnar protrusions that define a substrate distance from a substrate. 11. An electronic device comprising a liquid crystal device as defined in claim 1 in a display section.