JPH10177348A - Reflection type liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve optical characteristics such as reflection luminance and a reflection wavelength range by giving scattering reflection characteristics to a 1st liquid crystal layer where external light is made incident and regular reflection characteristics to a 2nd liquid crystal layer. SOLUTION: A separate layer 3 is arranged opposite to a 1st substrate separately to sandwich the 1st liquid crystal layer 11 with the 1st substrate and a 2nd substrate is arranged opposite to the separate layer 3 separately to sandwich the 2nd liquid crystal layer 12. The 1st liquid crystal layer 11 has liquid crystal molecules 11a controlled to irregular orientation on the intersurface on the side of the 1st substrate and liquid crystal molecules 11b to uniform orientation on the intersurface on the side of the separate layer 3. The 2nd liquid crystal layer 12, on the other hand, has liquid crystal molecules 12a and 12b controlled to uniform orientation on both the intersurfaces on the sides of the separate layer 3 and 2nd substrate. Thus, the 1st liquid crystal layer 11 on which external light is made incident is given scatter reflection characteristics and the 2nd liquid crystal layer 12 on which light is made incident from the 1st liquid crystal layer 11 is given regular reflection characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a reflection type liquid crystal display device.

[0002]

2. Description of the Related Art In general, a liquid crystal display element is composed of a pair of substrates which are formed with electrodes and an alignment film sequentially formed on opposing surfaces and are spaced apart from each other, and a liquid crystal layer sandwiched between the substrates. . In such a liquid crystal display element, a voltage is applied to the liquid crystal layer by the pixel electrode. In particular, in recent years, as a liquid crystal display element used for an active matrix display system, a liquid crystal display element in which a driving element such as a thin film transistor (TFT) is connected to the pixel electrode has been developed and put into practical use.

[0003] Among the constituent materials of the liquid crystal display element as described above, the liquid crystal material is used as an optical switching element by changing its alignment / alignment state by an externally applied electric field / magnetic field and the like, and changing its optical properties. Function. In general, a light component controlled by a polarizing plate is controlled by changing a liquid crystal arrangement to display a bright state and a dark state, and a twisted nematic liquid crystal element (TN Twisted Nematic) or a surface stable ferroelectric liquid crystal element ( SSFLC Surface Stabilized F
For example, an erro-electric liquid crystal (AFLC) or an anti-ferroelectric liquid crystal (AFLC) device is used. In these devices, the light use efficiency is about 50% at the maximum because a polarizing plate is used.

Further, a liquid crystal material is dispersed in a polymer material,
By performing optical switching between the scattering state and the non-scattering state, a polymer-dispersed liquid crystal element (Polymer Dispersed Liquid Crystal PDLC) or the like that does not require a polarizing plate has been proposed, and its practical application is aimed at. But PDLC
The light utilization efficiency in the reflection state is relatively small due to low scattered light and the like.

Further, there has been proposed a liquid crystal element utilizing a mode called a selective reflection mode of a cholesteric liquid crystal material, which selectively reflects light having a specific wavelength due to a complicated twisted structure of the liquid crystal material (George H.). Heilmeier, Joel
E. Goldmacher et al. Appl. Phys. Lett., 13 (1968), 132)
. This liquid crystal device is a planar (Plana) device in which the helical axis of the cholesteric liquid crystal is aligned almost perpendicular to the device substrate surface.
r) Scattering (or weakness) in a transparent state with selective reflection in the structural state or reflection of light wavelengths outside the visible light range, and in a focal conic structural state in which the helical axis is almost parallel to the substrate surface. (Scattering) state. Furthermore, even after removing the external market,
In order to exhibit a storage effect that each alignment state is temporarily held, this mode has been attempted to be applied to large-scale matrix driving.

This mode, which does not require a polarizing plate, has high transmittance in the transparent state and high light use efficiency, but has problems such as low contrast in the scattering state, and it is difficult to exhibit sufficient display characteristics. . In addition, since the storage property in the focal conic state is relatively unstable, there is a problem that reliability is low. Also, in order to reflect only a specific wavelength region of right or left circularly polarized light,
The limit value of the reflectance in the planar structure is 50%.

[0007]

As described above, in a liquid crystal display device using a polarizing plate, it is difficult to increase the light use efficiency. On the other hand, when a polarizing plate is not required, it is sufficient. However, there is also a problem that a high contrast cannot be obtained and the reliability is low. There is a demand for the development of a liquid crystal display device that can display light with high efficiency and high contrast. Therefore, an object of the present invention is to provide a reflective liquid crystal display device having high reflection luminance and good visibility.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a first substrate having a transparent electrode formed thereon, a separation layer disposed to face the first substrate, and a separation layer. A first liquid crystal layer sandwiched between a layer and the first substrate, to which external light is incident, a second substrate having a pixel electrode disposed to face the separation layer at a distance from the first liquid crystal layer, and the separation layer; A second liquid crystal layer interposed between the second substrate and the second liquid crystal layer, wherein the separation layer exhibits a collimation effect having a bias in a light transmission direction, and the alignment or alignment of liquid crystal molecules in the first liquid crystal layer. Is a non-uniform state showing scattering reflection or transmission, and the orientation or alignment of the liquid crystal molecules of the second liquid crystal layer is
Provided is a reflective liquid crystal display element characterized by being in a uniform state showing regular reflection characteristics.

Hereinafter, the present invention will be described in detail. In the liquid crystal display device of the present invention, as the liquid crystal material, a chiral nematic liquid crystal which is a mixture of a cholesteric liquid crystal and a nematic liquid crystal is used. In the chiral nematic liquid crystal, a perfluoroalkyl compound-based material is contained in an amount of 1 to 3 wt.
% Mixed liquid crystal material (Japanese Patent Application No. 7-341185)
Is advantageous because the arrangement of the liquid crystal molecules can be stabilized.

In the liquid crystal display device of the present invention, a separation layer for causing two liquid crystal layers to be present independently is one that exhibits a collimating effect having a bias in the light transmission direction. It is preferable to have means for easily applying a voltage between the first and second liquid crystal layers. Examples of such means include anisotropic conductive characteristics and a through-hole type electrode structure.

It is preferable that the optical characteristics of the material of the separation layer be selected in accordance with the display mode of the liquid crystal material used for the liquid crystal layers provided above and below the separation layer. That is, the optical characteristics required for the separation layer material are different between the case where the circularly polarized light selective reflection of the two liquid crystal materials arranged above and below the separation layer is different from each other and the case where they are equal. For example, when the circularly polarized light selective reflection of adjacent liquid crystal materials is different from each other in optical characteristics of independent liquid crystal regions, specifically, one liquid crystal material reflects right circularly polarized light and the other liquid crystal material reflects left circularly polarized light. When light is reflected, it is preferable that the separation layer existing between the liquid crystal layers does not show optical anisotropy. In addition, there is no problem if the selected wavelength profiles of the independent liquid crystal regions are equal between the independent regions that are in contact with each other, but in order to reflect a wide wavelength region and enable a whitish color display, two liquid crystal layers are required. It is preferable to provide a difference of about 30 nm to 100 nm in the center wavelength of the selective reflection wavelength.

Further, when the circularly polarized light selective reflection is equal between the liquid crystal material of the first layer and the liquid crystal material of the second layer of the two liquid crystal layers disposed above and below the separation layer, ie, the first layer and the second layer
When the liquid crystal materials of the layers have the same twist direction, the separation layer present between the liquid crystal layers is preferably a material exhibiting optical anisotropy. Particularly in this case, the selective reflection center wavelength λ ′ = n′p (n ′ is the average refractive index of the liquid crystal, p
Is the twist pitch of the liquid crystal) and the accompanying reflection wavelength width Δ
The phase difference between the ordinary light component and the extraordinary light component of light at λ = Δnp (Δn is the refractive index anisotropy of the liquid crystal material of the second layer)
It is preferable to show an optical anisotropy that can be shifted by a half wavelength (λ ′ / 2).

As described above, the optical characteristics required for the separation layer change according to the characteristics of the liquid crystal material disposed above and below the separation layer. Therefore, the material for forming the separation layer is appropriately determined according to the liquid crystal material. You can choose.

In the liquid crystal display device according to the present invention, the orientation or arrangement of liquid crystal molecules in the first liquid crystal layer to which external light is incident, and the liquid crystal molecules from the first liquid crystal layer through the separation layer through which light is incident. The orientation or arrangement of the liquid crystal molecules in the second liquid crystal layer is different from that in the second liquid crystal layer, thereby improving the optical characteristics such as the reflection luminance and the reflection wavelength range. Specifically, the orientation or alignment of the liquid crystal molecules in the first liquid crystal layer is made to be in a non-uniform state showing scattering reflection or transmission, while the orientation or alignment of the liquid crystal molecules in the second liquid crystal layer is mainly caused by the incidence of light. It is in a uniform state showing regular reflection characteristics of returning reflected light in the same direction as the direction.

In order to control the alignment state of the liquid crystal molecules in the first liquid crystal layer as described above, an interface in contact with the liquid crystal material of the substrate located on the light incident surface of the first liquid crystal layer, that is, the first substrate It is preferable to provide a polymer alignment film on the surface for stably maintaining the liquid crystal molecules in an irregular alignment state. On the other hand, after a polymer alignment film is provided on the interface between the opposing substrate and the liquid crystal material, that is, on the first liquid crystal layer side of the separation layer, an alignment treatment for uniformly controlling the alignment of liquid crystal molecules in a certain direction is performed. It is preferred to do so. As the orientation treatment, for example, a brushed cloth is wound around a roller, is moved in a certain direction while rotating, and the polymer oriented film surface provided on the substrate surface is uniformly rubbed (rubbing treatment). Alternatively, at the interface of the first liquid crystal layer in contact with the separation layer, the liquid crystal molecules may stably maintain an irregular alignment state, similarly to the first substrate side.

Further, in order to impart regular reflection characteristics to the second liquid crystal layer, both interfaces in contact with the liquid crystal substance of the opposing substrate,
That is, it is preferable that the liquid crystal molecule alignment on the surface of the second substrate and the surface of the separation layer is uniformly controlled in a certain direction. It is effective to control the alignment in the second liquid crystal layer by performing a uniform alignment process (rubbing of the polymer alignment film) in the first liquid crystal layer.

Here, the alignment direction of the liquid crystal molecules at the interface where the alignment of the first liquid crystal layer and the second liquid crystal layer is uniformly controlled in a certain direction is different if the alignment direction in each surface is a certain direction. It is not necessary to match with the orientation direction in the plane of (1).

In the liquid crystal display element of the present invention, as a spacer material for keeping the space constituting the liquid crystal layer constant, a resin ball conventionally used for a liquid crystal element may be used and may be sprayed on the substrate surface. However, it is preferable to use a columnar insulator formed at a specific interval on each substrate surface. In the present invention, the spacer also acts as a pillar for supporting the separation layer, and such an insulator pillar can be formed by a light exposure and etching process using, for example, photosensitive polyimide.

Here, the liquid crystal display device of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view schematically showing an example of the reflection type liquid crystal display device of the present invention. As shown in FIG.
A common electrode 4 and an alignment film 13 are sequentially formed on the surface of the upper glass substrate 1 to form a first substrate, and a separation layer 3 is disposed on the first substrate so as to face the first substrate.
The first liquid crystal layer 11 is sandwiched together with the substrate. The separation layer 3 has separation layer pixel electrodes 7 and 8 on both surfaces thereof.
Are formed, and these have a through-hole type surface electrode structure electrically connected by the through-holes 9. Alignment layers 15 and 16 are formed on the separation layer pixel electrodes 7 and 8, respectively. The separation layer 3 is preferably made of a material such as glass that does not optically rotate optically, but many transparent substrate materials can be used as long as the material does not exhibit optical rotation even in a polymer film.

On the other hand, a TFT 5 is provided on the second glass substrate 2.
And a pixel electrode 6, on which a black absorbing layer 10 and an alignment layer 14 are formed.
Of the substrate. The second substrate is provided with the aforementioned separation layer 3.
And the second liquid crystal layer 12 is interposed therebetween.

The above-mentioned alignment layers 13, 14, 15, 16
Is made of a polyimide film for stabilizing the adsorption of liquid crystal molecules, and it is preferable that at least the alignment layers 14 and 16 are subjected to an alignment treatment. When the alignment film is formed, it is more preferable to form a columnar spacer for keeping the cell interval constant using the same alignment film material, but a resin spacer ball dispersed on the substrate surface by spraying may be used.

In each of the first and second liquid crystal layers, a right-handed material and a left-handed material having a twisted structure between liquid crystal molecules are sandwiched, and reflect and scatter light with a predetermined reflection wavelength width. As further shown, the first liquid crystal layer 1
1, the liquid crystal molecules 1 at the interface on the first substrate side
The orientation of 1a is non-uniform, and the orientation of the liquid crystal molecules 11b at the interface on the separation layer 3 side is controlled to be uniform. On the other hand, in the second liquid crystal layer 12, the separation layer 3
The orientation of the liquid crystal molecules 12b and 12a at both the interface on the side and the second substrate side is controlled to be uniform. The alignment of such liquid crystal molecules in the liquid crystal display device shown in FIG.
And 16 can be controlled by performing an orientation treatment. Here, it is preferable that the relationship between the distance (X) between the holes in the through-hole separation layer and the thickness (D) of the substrate satisfies the following expression (1).

[0023]

(Equation 1)

As long as this condition is satisfied, the collimation effect in the through-hole separation layer greatly affects the liquid crystal display characteristics. According to the present invention, the transmission, scattering, and reflection characteristics of light in the liquid crystal layers located above and below the separation layer are effectively exhibited. When a substrate having a small collimating effect is used as the separation layer, the loss of reflected light due to the collimating effect is reduced, but on the other hand, display quality is significantly reduced due to a shift (parallax) of reflected light between the upper and lower liquid crystal layers.

Therefore, in the present invention, by utilizing the collimation effect in the separation layer, it is difficult to recognize the light reflection shift between the first and second liquid crystal layers located above and below the separation layer. In addition, the loss of the reflected light in the separation layer can be reduced by making the reflection of the second liquid crystal layer into which light is incident via the separation layer mainly a regular reflection.

This effect will be described with reference to FIG. FIG.
Is a non-uniform state in which the separation layer shows a collimating effect, but the upper and lower liquid crystal layers show scattering reflection from each other. In this liquid crystal display device, since the liquid crystal molecules of the first liquid crystal layer 22 to which the external light is incident are irregularly arranged, the incident light 21 is scattered by the molecular arrangement, and a part of the incident light 21 is partly passed through the through hole separation layer. The light passes through the second liquid crystal layer 23 and reaches the second liquid crystal layer 23. The light 25 reflected by the second liquid crystal layer 23 passes through the through hole separation layer again and reaches the first liquid crystal layer.
At this time, since the second liquid crystal layer exhibits scattering reflection, the angle of reflection at the second liquid crystal layer is increased, and the progress of light is hindered by the through-hole electrode formed in the through-hole separation layer 24. It becomes difficult for the reflected light to reach the first liquid crystal layer 22. As shown in the figure, when the second liquid crystal layer molecular arrangement 23 is irregular, the reflection angle becomes particularly large, and the light use efficiency is poor.

On the other hand, in the present invention, since the liquid crystal molecule arrangement in the second liquid crystal layer 12 is uniform as shown in FIG. 1, the light transmitted through the separation layer through-hole substrate 3 in parallel. Is reflected almost specularly.
Therefore, light from the second liquid crystal layer can be effectively reflected and transmitted without being hindered by the through-hole electrode formed in the through-hole. Further, the reflected light 19 that has passed through the separation layer 3 is output as transmitted scattered light 20 scattered by the first liquid crystal layer 11 having light scattering properties, so that a liquid crystal display element having a wide viewing angle can be configured. Is possible.

In the present invention, the specular reflection state means that the direction of the reflected light is the same as the incident direction of the light, which will be described in more detail. In general,
The reflection type liquid crystal display element has two kinds of reflection characteristics as shown in the graph of FIG. In the drawing, the reflection characteristic represented by the curve B is a characteristic close to that of white paper or a perfect diffusion plate, and is a reflection state in which a reflection luminance peak does not appear in a specific direction. The element showing the “specular reflection state” in the present invention is:
Unlike the reflection characteristic represented by the curve B, the reflection characteristic shows a reflection luminance peak in a specific direction as represented by the curve A.

Here, in the liquid crystal display device of the present invention shown in FIG. 1, the second liquid crystal layer 1 to which light is incident via the separation layer 3 is used.
No. 2 is desired to have an effect by having a reflection state having a characteristic represented by the following equation (2).

[0030]

(Equation 2)

As shown in FIG. 3, of the reflected light of the light emitted from the light source 31 to the liquid crystal display element 30, the luminance of the reflected light measured by the luminance meter 32 installed in front of the liquid crystal display element is shown. Assuming that R ₀ is R ₀ and the reflection luminance in a direction inclined by 30 ° from the front is R ₃₀ , the effect of the present invention is remarkably exhibited in a reflection state satisfying the condition represented by the following equation (2).

As described above, the reflection type liquid crystal display device of the present invention has the first and second liquid crystal layers separated from each other by the separation layer having a collimating effect, and the first liquid crystal layer to which external light is incident. In addition to controlling the orientation or arrangement of liquid crystal molecules in the liquid crystal layer to a scattering or reflecting state, the light transmitted through the first liquid crystal layer is incident on the second liquid crystal layer through the separation layer. Since the orientation or the arrangement is controlled to the regular reflection state, it is possible to improve the optical characteristics such as the reflection luminance and the reflection wavelength range.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the drawings. However, these embodiments are intended to facilitate understanding of the present invention, and the gist of the present invention is changed. Various modifications can be made without departing from the scope. (Example 1) First, a polyimide (Optomer AL) was formed on a surface of a first glass substrate on which a transparent electrode was formed, in contact with a liquid crystal layer.
-3046: Nippon Synthetic Rubber Co., Ltd.) was cast to a thickness of 40 nm by a spinner to form an alignment film, which was used as a first substrate (upper substrate). A black resist: C is formed on the second glass substrate on which the TFT and the pixel electrode are provided.
After forming a black absorbing layer with K-6020L (manufactured by Fuji Hunt Technology), an alignment film was formed using the same polyimide as described above to obtain a second substrate (lower substrate).

Further, through holes having a diameter of 30 μm are formed at predetermined positions of a glass substrate having a thickness of 0.3 mm by etching at intervals of 150 μm, and the bumps are melt-filled therein to establish electrical conduction between the front and back surfaces. Was. Next, ITO was formed on both surfaces by sputtering, each pixel electrode was formed by etching, and an alignment film was formed on each pixel electrode using the same polyimide as described above to obtain a through-hole separation layer.

Of the alignment films formed on the surfaces of the first and second substrates and the through-hole substrate formed as described above, all the alignment films except for the alignment film formed on the surface of the first substrate , An alignment treatment was performed by a rotational rubbing method to control the alignment of the liquid crystal molecules on the separation layer side in the first liquid crystal layer and the liquid crystal molecules in the second liquid crystal layer.

Thereafter, an epoxy adhesive for bonding is applied to predetermined positions on the upper and lower substrate surfaces by a conventional method, and resin spacer balls having a diameter of 2 μm are formed on the substrate surface at a density of 100 balls / mm ² or more. Sprayed to be.

The first film having the alignment film formed as described above
After applying a sealant to the periphery of the second substrate, the empty cell was formed by sandwiching the through-hole separation layer and bonding the spacer balls to each other so as to support the separation layer. Liquid crystal materials having different compositions were injected into two independent spaces defined by the substrate and the separation layer from respective injection ports provided at the edge of the substrate. The upper liquid crystal layer (first liquid crystal layer) has a nematic liquid crystal BL011 (MER).
CK) 63% and chiral agent CB15 (MERCK)
And chiral nematic liquid crystal mixed with 37 wt% (manufactured by MERCK) and a chiral agent S811 (manufactured by MERCK). A chiral nematic liquid crystal mixed with 29 wt% was injected.

FIG. 4 is a sectional view schematically showing the liquid crystal display device manufactured in this embodiment. As shown in FIG. 4, in the liquid crystal display element of the present embodiment, among the liquid crystal molecules in the first liquid crystal layer 11, the liquid crystal molecules 11b at the interface in contact with the alignment film 15 of the separation layer 3 are uniformly aligned. And the liquid crystal molecules 11a in contact with the alignment film 13 of the first substrate.
Is a scattering arrangement state. In the second liquid crystal layer 12, the liquid crystal molecules 12a and 12b that are in contact with the interface between the two facing alignment films 14 and 16 are all in a uniform alignment state. (Example 2) In the same manner as in Example 1 described above, first and second substrates having an alignment film formed on the surface, and a through-hole separation layer were obtained. The surface of the second liquid crystal layer in contact with the liquid crystal molecules, that is, the alignment film formed on the second substrate, and the alignment film formed on the surface of the through hole separation layer facing the second substrate out of the alignment films. 2nd rotation rubbing treatment
The alignment of only the liquid crystal molecules of the liquid crystal layer was controlled.

Next, after forming an empty cell in the same manner as described above, the same liquid crystal material as described above is injected into each of the two independent spaces defined by the substrate and the separation layer. An element was obtained.

FIG. 5 is a sectional view schematically showing the liquid crystal display device manufactured in this embodiment. As shown in FIG. 5, in the liquid crystal display element of the present embodiment, the liquid crystal molecules 11b at the interface in contact with the alignment film 15 of the separation layer 3 among the liquid crystal molecules in the first liquid crystal layer 11, and the first substrate The liquid crystal molecules 11a in contact with the alignment film 13 are all in a scattering alignment state. In the second liquid crystal layer 12,
The liquid crystal molecules 12a and 12b that are in contact with the interface between the two facing alignment films 14 and 16, respectively, are both in a uniform alignment state. (Comparative Example) In the same manner as in Example 1 described above, first and second substrates having an alignment film formed on the surface, and a through-hole separation layer were obtained. After forming an empty cell in the same manner as described above, except that no rotational rubbing treatment is applied to any of the alignment films, the two independent spaces defined by the substrate and the separation layer respectively include the same liquid crystal material as described above. Was injected to obtain a liquid crystal display device of a comparative example.

FIG. 7 is a sectional view schematically showing the liquid crystal display device manufactured in the comparative example. As shown in FIG. 7, in the liquid crystal display element of the comparative example, the liquid crystal molecules 51a and 51b in contact with the two facing alignment films 53 and 55 in the first liquid crystal layer 51 are both in a scattering alignment state. Also, in the second liquid crystal layer 52, the liquid crystal molecules 52a and 52b that are in contact with the interface between the two facing alignment films 54 and 56, respectively, are in a scattering alignment state. Table 1 below summarizes the display characteristics of the liquid crystal display devices of the present invention (Examples 1 and 2) and the liquid crystal display device of the comparative example together with the device structure.

[0042]

[Table 1]

As shown in Table 1, the liquid crystal display device of the present invention has a reflectance of about 60% and a contrast of 3%.
It is high as 5 or more, which indicates that the display device has good display characteristics. On the other hand, in the liquid crystal display element of the comparative example in which the second liquid crystal layer is not provided with regular reflection characteristics, the reflectance is only 46% and the contrast is inferior to 28.

Further, the reflectance characteristics of the liquid crystal display device of the present invention and the liquid crystal display device of the comparative example are shown in FIGS. 8 and 9, respectively.
Is shown in the graph. As shown in the graph of FIG. 8, the liquid crystal display device of the present invention shows a reflectance of 60% or more for a wavelength of 400 nm or more, and the reflectance exceeds 70% when the wavelength exceeds 560 nm. Has reached. On the other hand, as shown in the graph of FIG. 9, the reflectance of the liquid crystal display element of the comparative example is only 30% at the wavelength of 560 nm, and the maximum value of the reflectance is about 40%.

[0045]

As described above, according to the present invention,
In a multi-layer liquid crystal display device, the first liquid crystal layer to which external light is incident has a scattering and reflection characteristic, while the second liquid crystal layer to which light from the first liquid crystal layer is incident is positive. Since the reflective characteristics are provided, a reflective liquid crystal display device having improved optical characteristics such as a reflection luminance and a reflection wavelength range is provided. Such display elements have high light use efficiency and can perform display with high contrast, and their industrial value is large.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a liquid crystal display device of the present invention.

FIG. 2 is a graph showing the reflection characteristics of a reflection type liquid crystal display element.

FIG. 3 is a schematic diagram for measuring a reflection profile.

FIG. 4 is a cross-sectional view schematically showing the liquid crystal display element of Example 1.

FIG. 5 is a cross-sectional view schematically showing a liquid crystal display device of Example 2.

FIG. 6 is a cross-sectional view schematically showing a conventional liquid crystal display element.

FIG. 7 is a cross-sectional view schematically showing the structure of a conventional liquid crystal display element.

FIG. 8 is a graph showing display characteristics of the liquid crystal display device of the present invention.

FIG. 9 is a graph showing display characteristics of a liquid crystal display element of a comparative example.

[Explanation of symbols]

1, 41: Upper glass substrate 2, 42: Lower substrate 3, 43: Separation layer substrate 4, 44: Common electrode 5, 45 ... TFT 6, 46 ... Pixel electrode 7, 8, 47, 48 ... Separation layer pixel electrode 9, 49 ... separation layer through hole 10, 50 ... black absorption layer 11, 51 ... first liquid crystal layer 12, 52 ... second liquid crystal layer 13, 14, 15, 16, 53, 54, 55, 56 ... orientation Film 17: incident light 18: reflected light from the first liquid crystal layer 19: light transmitted through the separation layer 20: transmitted scattered light 21: incident light 22: first liquid crystal layer 23: second liquid crystal layer 24: through Hole separation layer 25: light reflected by the second liquid crystal layer 30: liquid crystal element 31: light source 32, 33: luminance meter

Claims (4)

[Claims] A first substrate on which a transparent electrode is formed; a separation layer disposed to face the first substrate so as to be spaced apart from the first substrate; and an external light incident between the separation layer and the first substrate. A first liquid crystal layer to be provided, a second substrate having a pixel electrode disposed to face the separation layer at a distance, and a second liquid crystal layer sandwiched between the separation layer and the second substrate. The separation layer exhibits a collimation effect having a bias in a light transmission direction, and the orientation or arrangement of the liquid crystal molecules of the first liquid crystal layer is in a non-uniform state showing scattering reflection or transmission. The liquid crystal molecules of the second liquid crystal layer are aligned or arranged in a uniform state exhibiting specular reflection characteristics. 2. In the first liquid crystal layer, alignment of liquid crystal molecules at an interface in contact with the first substrate is irregular,
The liquid crystal molecules on the surface in contact with the separation layer opposed thereto are controlled so as to be arranged in a certain direction. With the molecule,
2. The method according to claim 1, wherein the control is performed so as to be arranged in a certain direction.
3. The reflective liquid crystal display device according to item 1. 3. In the first liquid crystal layer, the orientation of liquid crystal molecules at an interface in contact with the first substrate and a surface in contact with the separation layer is irregular, and in the second liquid crystal layer, Both the liquid crystal molecules at the interface in contact with the second substrate and the surface in contact with the separation layer,
2. The method according to claim 1, wherein the control is performed so as to be arranged in a certain direction.
3. The reflective liquid crystal display device according to item 1. 4. The liquid crystal display according to claim 1, wherein the separation layer has means for electrically connecting the first liquid crystal layer and the second liquid crystal layer for each pixel electrode formed in the second liquid crystal layer. Reflective liquid crystal display device.