JP2002311425A - Liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make visibility satisfactory by making a liquid crystal image easily viewable in a liquid crystal display. SOLUTION: A reflection layer 8A is provided on the downside of a liquid crystal layer 38 and a surface on the side of the liquid crystal layer of the reflection layer is provided with a rugged pattern to orient reflected light to a space outside of a light source reflecting surface (external space). When a predetermined position outside the external space is defined as a conversion point 5, the reflection layer is centered around a position at which a perpendicular line of the conversion point 5 and a horizontal line of the reflection layer are crossed, the rugged pattern is provided with a plurality of projected parts having inclined surfaces and furthermore, an inclination angle of an inclined surface is a first pattern to become larger as it is set apart from the center side. In addition, the rugged pattern can also be defined as a second pattern to become fine as a pitch to form the projected part is set apart from the center side by defining height of the project part as fixed. And the center is positioned, for example, on a segment to bisect a liquid crystal screen. Thus, reflection of a light source on the liquid display image is prevented, the liquid crystal image becomes easily viewable and the visibility becomes satisfactory.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display, and more particularly to a reflection type liquid crystal display.

[0002]

2. Description of the Related Art In recent years, personal computers (P
Liquid crystal display devices are being used for display devices used in electronic devices such as C), televisions, word processors, and videos. In such electronic devices, in order to further enhance the functions, reduce the size, save power, and reduce the cost, the so-called backlight is used without using a so-called backlight. A liquid crystal display device for displaying an image (hereinafter referred to as a reflective liquid crystal display device) is being used. As described above, in the reflection type liquid crystal display device,
Since no backlight is used, it is important whether or not the liquid crystal display surface can be illuminated from behind by efficiently utilizing externally incident light.

Here, a conventional reflection type liquid crystal display device will be described with reference to FIG. In the reflection type liquid crystal display (liquid crystal panel) 12 shown in FIG. 12A, for example, a reflection film 34 is formed on a lower substrate 11 formed of a transparent material such as glass. A liquid crystal layer 38 is provided on the reflection film 34.
, A color filter substrate (CF) 35 is disposed, and a light diffusion plate 3 is disposed on the CF 35 via an upper substrate (for example, a glass plate) 2.

In the illustrated liquid crystal panel 12, light incident from the outside (hereinafter referred to as ambient light) is reflected by a reflection film 34. However, since the reflection plate film 34 is a flat surface, a specular reflection method is used. Other than that, it does not reflect ambient light, and as a result, the viewing angle of the liquid crystal panel 12 becomes narrow. Therefore, in the example shown in FIG. 13, the light diffusion plate 3 is disposed on the upper substrate 2, and the ambient light reflected by the reflection film 34 (that is, the reflected light)
Are diffused by the light diffusion plate 3 as shown by solid arrows in the figure, thereby widening the viewing angle of the liquid crystal panel 12.

As described above, the ambient light specularly reflected by the reflection film 34 is diffused by the light diffusing plate 3, and the light in the specular reflection direction (hereinafter, referred to as specular reflection light) and the light in the other direction (hereinafter, diffusion light). The light is emitted from the light diffusion plate 3 as light), and the direction of specular reflection is the brightest (that is, the specular reflected light is the strongest). The diffuse light becomes weaker as the angle increases from the specular light). For example, as shown in FIG. 12B, when it is assumed that ambient light having an incident angle of 0 degree is incident on the liquid crystal panel 12, the specular reflection angle of 0 degree is the brightest, and the reflection angle is separated from the specular reflection angle of 0 degree. It will be getting darker.
Then, as shown in the figure, when the specular angle exceeds 0 ° ± 10 °, the brightness becomes extremely small. That is, even if the diffusion plate 3 is disposed on the upper substrate 2, a brightness peak appears in the regular reflection direction.

Referring to FIG. 13, FIG.
In FIG. 12A, a human eye 49 is separated from the surface of the liquid crystal panel 12 by a predetermined distance (for example, about 30 cm).
Is shown. Now, for convenience of explanation, it is assumed that ambient light is perpendicularly incident on the liquid crystal panel 12 and is reflected at points A, B, and C of the reflection film 34, and the human eye 49 is positioned above the point B. Shall be

[0007] As described with reference to FIG.
The light reflected at points A, B, and C of No. 4 and diffused by the diffusion plate 3 has the highest brightness in the reflection direction (in the illustrated example, in the vertical direction, for example, at an emission angle of 0 °). As described above, since the human eye 49 is positioned above the point B, the light reflected at the point B is perceived to be the brightest by the human eye 49. On the other hand, the light reflected at the point A has no human eye 49 positioned in the direction of reflection, so the brightest light among the light diffused by the light diffusion plate 3 is the human eye 4.
9 and the human eye 49 is about 30 cm away from the surface of the liquid crystal panel 12, light having a diffusion angle of 10 degrees reaches the human eye 49 most as shown in FIG. .

Similarly, the light reflected at the point C does not have the human eyes 49 positioned in the direction of reflection, so that the brightest light diffused by the light diffusion plate 3 does not reach the human eyes 49. , The human eye 49 is 30 degrees from the surface of the liquid crystal panel 12.
At a distance of about cm, light having a diffusion angle of −10 degrees reaches the human eye 49 most.

As described above, when the human eye 49 is positioned above the point B, the point B looks brightest,
As a result, points A and C appear dark, so that even when light other than the vertically incident light is considered, point B looks brightest as shown in FIG. 14B (point B has a brightness peak). ), It becomes darker as it moves away from point B.

This means that if the position of the eye 49 is above the point A, the point A looks brightest and becomes darker as the distance from the point A increases. Similarly, if the position of the eye 49 is above the point C, the point C looks brightest and becomes darker as the distance from the point C increases. Thus, FIG.
In the liquid crystal panel 12 shown in (a), a part that looks bright and a part that looks dark in the liquid crystal panel surface inevitably occur irrespective of the position of the human eyes 49, and there is a problem that the screen is extremely difficult for a user to see. is there.

In order to prevent such a problem, for example, a device in which a Fresnel lens layer (Fresnel lens sheet) is formed on the light diffusion plate 3 is known. Referring to FIG. 14, in the example shown in FIG. 14A, the same components as those in FIGS. 12A and 13A are denoted by the same reference numerals. In the illustrated example, a Fresnel lens layer 37 is formed on the light diffusion plate 3. The surface of the Fresnel lens layer 37 has a predetermined uneven shape (an uneven pattern), and the height of the uneven pattern is constant.
The pitch becomes finer from the center toward the periphery. For example, when the position of the human eye 49 is positioned at the point B, when the reflected light diffused by the light diffusing plate 3 (hereinafter referred to as reflected diffused light) is deflected by the Fresnel lens layer 37, its intensity is the strongest. A concavo-convex pattern is formed so that the light goes to the eyes 49.

When the Fresnel lens layer 37 is formed on the light diffusing plate 3 as described above, the light having the highest intensity of the reflected diffused light is directed to the eyes 49, and thus looks bright in the liquid crystal panel surface. There are few places and places that look dark, and the brightness in the liquid crystal panel surface can be made substantially constant (see FIG. 14B).

[0013]

By the way, FIG.
In the case of the liquid crystal display device shown in (a), the brightness in the liquid crystal panel surface can be made substantially constant, but when viewing the liquid crystal display image, the position of the user's eyes is the brightest in the entire liquid crystal panel. It must be in a visible position. In other words, the direction in which the entire liquid crystal panel looks brightest (the converging point) coincides with the specular reflection direction, and in order to view the display image on a bright screen, the human eyes 49 need to be positioned above the liquid crystal panel surface. There is.

However, as described above, human eyes 4
When the light source 9 is positioned above the liquid crystal panel, the light source such as the sun is located in the same direction as the direction of the reflected light, so that the light source such as the sun is inevitably placed on the liquid crystal panel screen, that is, the liquid crystal display image. It will be reflected in. As described above, when the light source is projected on the liquid crystal display image, the liquid crystal display image itself becomes extremely difficult for the user to see,
There is a problem that visibility is reduced.

An object of the present invention is to provide a liquid crystal display device in which a liquid crystal display image is easy to see and visibility is good.

[0016]

According to the present invention, there is provided a liquid crystal display device for displaying a liquid crystal screen by illuminating a liquid crystal layer using light incident on the surface of the display panel from the outside. Light incident from a direction perpendicular to the light-transmitting light passes through the liquid crystal layer, is reflected, and is provided with light-collecting means for condensing light in an emission area of an upper space of the display panel,
A perpendicular line drawn from the emission area to a plane including the display panel does not intersect with the display panel.

According to this invention, the light condensing means that the incident light incident on the display panel from the vertical direction passes through the liquid crystal layer, is reflected, and condenses on the emission area of the upper space of the display panel. Is provided, since a perpendicular drawn from the emission area to a plane including the display panel does not intersect with the display panel, light vertically incident on the surface of the display panel is superimposed on display information on the monitor screen to superimpose display information on the monitor screen. Does not interfere with visibility.

Further, the display panel has a diffusion plate disposed on the surface thereof, and the light condensing means has a reflection layer provided below the liquid crystal layer, and the reflection layer is formed of the liquid crystal. It is also an effective means of the present invention that the layer side surface has a concavo-convex pattern for directing the reflected light toward the emission region.

According to this technical means, since the diffusion plate is provided on the surface of the display panel, and the reflection layer having the uneven pattern for reflecting the reflected light toward the emission area is provided below the liquid crystal layer. In addition, the uneven pattern is not visually recognized by being superimposed on the information on the monitor screen.

Further, the light condensing means has a reflection layer provided below the liquid crystal layer and a lens layer provided above the liquid crystal layer, and the lens layer is formed of the liquid crystal. The surface on the side opposite to the layer may have a concavo-convex pattern directed toward the emission region.

In this case, it is preferable that a diffusion layer for diffusing light is formed above the liquid crystal layer, and the lens layer is disposed on the diffusion layer.

According to such a technical means, the lens layer on which the uneven pattern is formed can be configured to be removable, and light is present from the front or side of the monitor screen, and enters the monitor screen perpendicularly. When there is no light coming,
The monitor screen can be visually recognized by removing the lens layer, and when there is light that enters perpendicularly to the monitor screen, the monitor screen can be visually recognized using the lens layer.

Further, the uneven pattern has a plurality of convex portions having an inclined surface, and the inclination angle of the inclined surface intersects a perpendicular line drawn from the emission area to a plane including the display panel. It is also an effective means of the present invention to form it so that it becomes larger as it gets farther from the camera.

According to such a technical means, the reflected light passing through the liquid crystal layer can be focused on the emission area of the upper space deviating from the liquid crystal screen, and the light vertically incident on the display panel surface is displayed on the monitor screen. It does not interfere with the visibility of the monitor screen by being superimposed on the information.

Further, the uneven pattern has a plurality of convex portions having inclined surfaces, and a pitch at which the convex portions are formed with the height of the convex portions of the inclined surface being constant is changed from the emission area to the display area. It is also an effective means of the present invention that the perpendicular line drawn on the plane including the panel is formed so as to become finer as it goes away from the point of intersection with the plane.

According to this technical means, the height of the convex portion of the inclined surface is constant, and the pitch at which the convex portion is formed is perpendicular to the plane including the display panel from the emission area and intersects with the plane. Since it is formed so as to become finer as it goes away from the point, the thickness of the lens layer for forming the uneven pattern can be made thin.

Further, it is an effective means of the present invention that the center of the emission area is positioned on a line segment bisecting the liquid crystal screen. According to such technical means, the monitor screen can be visually recognized equally on the left and right.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. It should be noted that the dimensions, materials, shapes, other relative arrangements, and the like of the components described in this embodiment do not limit the scope of the present invention unless otherwise limited.

Referring to FIG. 1, in the example shown in FIG.
2 to FIG. 14 are denoted by the same reference numerals. In a liquid crystal display (liquid crystal panel) 12A shown in FIG. 1A, a reflection plate (layer) 8A is formed on a lower substrate 11. A color filter substrate (CF) 35 is disposed on the reflection plate 8A with a liquid crystal layer 38 interposed therebetween.
The light diffusion plate 3 is arranged on the upper surface 5 via the upper substrate 2.

The reflection plate 8A includes, for example, a resin layer 8 having an uneven pattern formed on the surface thereof, and a reflection film 4 formed on the resin layer 8. The concavo-convex pattern formed on the surface of the resin layer 8 has a predetermined shape, as will be described later. As a result, the reflective film 4 formed on this concavo-convex pattern also has a predetermined shape.

As shown in FIG. 1 (a), each element (projection) of the concavo-convex pattern has an inclined surface.
This inclined surface is a surface that rises from the right side to the left side in the drawing. In other words, the inclined surface is a surface that is inclined toward the liquid crystal layer 38 from one side of the outer periphery defining the liquid crystal panel toward the other side. As shown in FIG. The pitch is getting finer toward.

Now, for example, as shown in FIG.
A predetermined distance (for example, 300 mm) upward from the diffusion plate 3
It is assumed that a liquid crystal display image is viewed at a distant position (when viewing the liquid crystal display image in the liquid crystal panel surface, the light of sunlight is specularly reflected by the diffusion plate 3 and the light source such as the sun 9 is liquid crystal as described above). Here, the surface defined within the liquid crystal panel surface at a predetermined distance above the diffusion plate 3 is referred to as a light source reflection surface). The light from the sun 9 which is vertically incident on the liquid crystal panel 12A is reflected by the reflection plate 8A.
Is reflected by As described above, the reflection plate 8A is formed with the concavo-convex pattern including a plurality of convex portions having inclined surfaces rising from the right side to the left side in the drawing.
Most of the incident light that strikes is reflected on the right side in the drawing with respect to the incident optical axis. In the illustrated example, the inclination angle of the convex portion located on the left side is larger than that of the convex portion located on the right side in the drawing, and as a result, the inclined surface of the convex portion located on the left side in the drawing hits the inclined surface. The more incident light, the more the light is reflected to the right.

The incident light reflected in this manner (that is, the reflected light) is diffused by the diffusion plate 3 and emitted to the outside as diffused light. At this time, if it is defined that the reflected light of each inclination angle in the above-mentioned uneven pattern forms the emission area 50 and comes to the light-collecting point 5 at a predetermined position of the light-emitting area 50, If the inclination angles in the concavo-convex pattern are defined so as to deviate from the light source reflection surface described above,
When viewing the liquid crystal display image, the human eyes 49 are not located in the light source reflection plane, and as a result, the reflection of the light source can be prevented. It is not necessary to emit all the reflected light at each inclination angle so as to be completely converged on the converging point 5, and it is a matter of course that the light may be shifted by about ± 15 °.

As described above, in FIG. 1A, the reflection angle of the incident light increases from the right side to the left side of the liquid crystal panel 12A. The reflected light is diffused by the light diffusion layer 3 and reaches the eyes 49, but all the reflected light from the reflection layer 8A is off the light source reflection surface (for example, the liquid crystal panel 12).
(A position 50 mm away from A and a position 300 mm above the position), the strongest light among the light diffused by the light diffusion layer 3 deviates from the light source reflection surface. I will head.

In other words, the center of the reflection layer 8A is located at the center of FIG.
(B) is at the position indicated by reference numeral 8Aa, and when the point at which this center is located is set as the reference point, the unevenness pattern is such that the inclination angle of the protrusion increases as the distance from the reference point side increases, and An inclined surface is formed so as to rise from the point side (to approach the liquid crystal layer 38). Hereinafter, the reflection layer 8A is called a mirror Fresnel lens layer, and the center 8Aa
Is called a mirror Fresnel lens center.

Referring now to FIG.
As shown in (a) in an enlarged manner, the inclination angle of each of the above-mentioned convex portions is represented by θ (deg). Also, as shown in FIG.
The distance from the mirror Fresnel lens center 8Aa to an arbitrary position of the mirror Fresnel lens layer 8A is x, and 2.5
Considering an inch liquid crystal panel, the relationship between the distance x and the inclination angle θ is represented as shown in FIG. That is, the concavo-convex pattern is formed such that the inclination angle θ increases as the distance x increases (hereinafter, this concavo-convex pattern is referred to as the first
Pattern). In this case, the inclination angle of the concavo-convex pattern increases as the distance from the center 8Aa of the mirror Fresnel lens increases, and as a result, the height of the convex portion increases.

On the other hand, as shown in FIG. 3 (b), the height of each convex portion is set to a predetermined constant height while the pitch of the concavo-convex pattern is reduced geometrically as the distance from the mirror Fresnel lens center 8Aa increases. (This uneven pattern is hereinafter referred to as a second pattern).

In the example shown in FIG. 2A, the inclination angle θ
Are 9.5 degrees, 14 degrees, and 18 degrees, the incident light hitting the inclined surface having these inclination angles
It is shown that the light is directed to a light condensing point located 50 mm away from A and 300 mm above that position.

When the height of the uneven pattern is large, the thickness of the liquid crystal layer 38 becomes uneven. As a result, it is desirable that the height of the uneven pattern is 1 μm or less. If the number of surfaces is increased, 1μm
The height of the concavo-convex pattern can be limited to the following. Therefore, the second pattern is used rather than the first pattern described above.
It is more desirable to use the following pattern.

Now, the panel size: 2.5 inches, the second pattern described above is used for the mirror Fresnel lens layer 8A, the height of the pattern (height of the convex portion) is set to about 1 μm, and the center 8Aa of the mirror Fresnel lens is formed. LCD panel 12
50mm from A, 50mm from liquid crystal panel 12A
The light collection efficiency at a position 300 mm above the distant position was 70% or more. In other words, 5 from the light source reflection surface
At a position separated by 0 mm, a light-collecting efficiency of 70% or more was obtained.

Here, referring to FIG. 4, when viewing the liquid crystal display image, the user (observer) may place the eye 4 in any position.
Consider whether the liquid crystal display image is most easily viewed when 9 is positioned. Generally, an observer is positioned at a predetermined distance above a line segment bisecting the liquid crystal panel surface (for example, 300
mm), the liquid crystal display image is most easily seen when looking at the liquid crystal panel surface. For this reason, it is necessary to position the above-mentioned condensing point at a position separated by a predetermined distance from the bisector. And in order to position the focal point like this,
The center 8Aa of the mirror Fresnel lens of the mirror Fresnel lens layer 8A may be positioned on the bisector 10, as shown in FIG.

Here, an example of forming the above-described mirror Fresnel lens layer 8A on the lower substrate 11 will be described with reference to FIGS. First, in forming the mirror Fresnel lens layer 8A, a mold called a stamper is manufactured. When manufacturing a stamper, FIG.
As shown in (a), after preparing the substrate 21,
For example, an electron beam resist 22 is applied to a predetermined thickness. Thereafter, as shown in FIG. 5B, the resist 22 is finely processed by an electron beam (electron beam).
An array master 23 having the above-described uneven pattern (first or second pattern) is created. Then, for example, a stamper material such as nickel is deposited on the array master 23 by electroforming to form a stamper 24 (see FIG. 5C). Thereafter, the stamper 24 is separated from the array master 23 (see FIG. 5D). Then, a pattern (inverted pattern) that is inverted from the concavo-convex pattern is formed on the stamper 24.

Next, as shown in FIG. 6A, a lower substrate (for example, a glass substrate or a transparent resin substrate; however, if the stamper transmits ultraviolet light, the lower substrate need not be transparent). After the ultraviolet curable resin 81 is dropped to a predetermined thickness on 11, the stamper 24 is lowered from above the ultraviolet curable resin 81, and the ultraviolet curable resin 81 is placed between the lower substrate 11 and the stamper 24. To spread the ultraviolet curable resin 81 between the lower substrate 11 and the stamper 24.

Next, as shown in FIG. 6B, the ultraviolet curing resin 81 is irradiated with ultraviolet rays from the lower substrate 11 side (U
V irradiation), and the ultraviolet curable resin 81 is cured by a photocuring reaction. When the ultraviolet curing resin 81 is cured, the stamper 24 is peeled from the ultraviolet curing resin 81. As a result, as shown in FIG. 6C, the reverse pattern of the stamper 24 is transferred to the ultraviolet curable resin 81 as the above-described concave / convex pattern, and the resin layer 8 is formed.

Thereafter, a thin metal film of, for example, Ag or Al is deposited on the resin layer 8 by sputtering.
As shown in FIG. 6D, the reflection film 4 is formed, whereby the reflection layer, that is, the mirror Fresnel lens layer 8A is formed on the lower substrate 11.

Further, another example in which the above-mentioned mirror Fresnel lens layer 8A is formed on the lower substrate 11 will be described with reference to FIG. As described with reference to FIG. 5, after forming the array master 23, the stamper 24 on which the reverse pattern is formed is formed by electroforming. Then, FIG.
As shown in (a), a resin 8B such as an acrylic resin is spin-coated on the lower substrate 11. Then, FIG.
As shown in FIG. 7, when the stamper 24 is lowered from above the resin 8B and the resin 8B is pressed, the reverse pattern of the stamper 24 is reverse-transferred onto the surface of the resin 8B as shown in FIG. Resin layer 8 having the above-mentioned uneven pattern
Is formed.

Thereafter, a metal thin film of, for example, Ag or Al is deposited on the resin layer 8 by sputtering.
As shown in FIG. 7D, the reflection film 4 is formed, whereby the reflection layer, that is, the mirror Fresnel lens layer 8A is formed on the lower substrate 11.

Referring to FIG. 8, another example in which the above-described mirror Fresnel lens layer 8A is formed on the lower substrate 11 will be described. As shown in FIG. 8A, a photosensitive resin 8C such as an acrylic resin is spin-coated on the lower substrate 11. Thereafter, as shown in FIG. 8B, the first mask 13 is used to irradiate ultraviolet rays from above the mask 13 (UV irradiation). In the following description, only one convex portion of the concavo-convex pattern is shown as enlarged by reference numeral C, but the concavo-convex pattern is formed in the same manner. The photosensitive resin 8C is partially exposed by the mask 13. Furthermore, the first
The photosensitive resin 8C is partially exposed using a second mask 14 different from the first mask 13 (see FIG. 8C). In this way, after exposing a plurality of times while changing the mask, development is performed (see FIG. 8D). As a result, the photosensitive resin 8C is formed in a step shape as shown in FIG. 8D. After that, the photosensitive resin 8C is heated to make the step-like portion flat (that is, an inclined surface), and to form the resin layer 8 having a convex portion, that is, a concave-convex pattern (FIG. 8E). .

Further, a thin metal film such as Ag or Al is deposited on the resin layer 8 by sputtering.
The reflection film 4 is formed as shown in FIG. Thereby, the mirror Fresnel lens layer 8 having the concavo-convex pattern
A is formed on the lower substrate 11. As described above, the concavo-convex pattern may be formed using photolithography.

In the above-described example, the liquid crystal layer 38 is used as the light condensing means.
The example in which the mirror Fresnel lens layer 8A is disposed below the liquid crystal panel 12B is described, for example, in the liquid crystal panel 12B shown in FIG.
As described above, the Fresnel lens layer 7 may be disposed on the diffusion plate (layer) 3. In FIG. 9A, the same components as those shown in FIG. 1A are denoted by the same reference numerals.

In the example shown in FIG. 9A, the concave / convex pattern of the Fresnel lens layer 7 has a larger inclination angle on the inclined surface of the convex portion located on the left side than on the inclined surface of the convex portion located on the right side in the drawing. Moreover, these inclined surfaces are surfaces that rise from the left side to the right side in the figure. In other words, the center of the Fresnel lens layer 7 is located at a position indicated by reference numeral 7a in FIG. 9B, and when the point at which the center is located is set as a reference point, the concave / convex pattern becomes more inclined as the distance from the reference point side increases. An inclined surface is formed so as to increase the angle. Hereinafter, the center 7a is referred to as a Fresnel lens center.

In the example shown, the light incident on the liquid crystal panel 12 B is reflected by the reflection film 34 and diffused by the diffusion plate 3.
Thereafter, the diffused light is deflected by the Fresnel lens layer 7. At this time, if each inclination angle in the above-mentioned uneven pattern is defined so that the condensing point of the diffused light is located at a predetermined position, that is, so that the condensing point deviates from the light source reflection surface, If you define each inclination angle,
When viewing the liquid crystal display image, the human eyes 49 are not located in the light source reflection plane, and as a result, the reflection of the light source can be prevented.

As described above, in FIG. 9A, the deflection angle of the diffused light increases from the right side to the left side of the liquid crystal panel 12B. The most intense light can be obtained by defining the concavo-convex pattern so that the deflection light from the Fresnel lens layer 7 is directed to a position off the light source reflection surface (for example, a position 50 mm away from the liquid crystal panel 12B and 300 mm above the position). Goes to a position off the light source reflection surface.

Referring now to FIG.
As shown in (a) in an enlarged manner, the inclination angle of each of the above-mentioned convex portions is represented by θ (deg). Further, as shown in FIG. 10B, the Fresnel lens layer 7 from the Fresnel lens center 7a.
Let x be a distance to an arbitrary position in FIG. 11 and consider a 2.5-inch liquid crystal panel.
(A). That is, the concavo-convex pattern is formed such that the inclination angle θ increases as the distance x increases (hereinafter, this concavo-convex pattern is referred to as a first pattern). In this case, the inclination angle of the concavo-convex pattern increases as the distance from the center 7a of the Fresnel lens increases, and as a result, the height of the convex portion increases.

On the other hand, as shown in FIG. 11 (b), while the pitch of the concavo-convex pattern is made geometrically finer as the distance from the center 7a of the Fresnel lens is increased, the height of each projection is set to a predetermined fixed height. (This uneven pattern is hereinafter referred to as a second pattern). FIG.
In the example shown in FIG. 0 (a), the inclination angle θ is 9.5 degrees, 14 degrees.
When the angle is set to 18 degrees, the diffused light deflected by the inclined surface having these inclination angles is directed 50 mm away from the liquid crystal panel 12A and toward the condensing point 300 mm above the position. . Now panel size: 2.5
Inches, the height of the pattern of the Fresnel lens layer 7 (height of the convex portion): 2 μm, the pattern pitch is 1 to 100 μm, and when the center 7 a of the Fresnel lens is 50 mm away from the liquid crystal panel 12 B, the position is 50 mm away from the liquid crystal panel 12 B. The light collection efficiency at a position 300 mm above
% Or more. In other words, 50 mm from the light source reflection surface
At a distant position, a light collection efficiency of 70% or more was obtained.

In the example shown in FIG. 9A, the center 7a of the Fresnel lens of the Fresnel lens layer 7 is, as described with reference to FIG. 4, a line segment bisecting the liquid crystal panel surface (bisector). It is desirable to be positioned above. The Fresnel lens layer 7 is formed by, for example, injection molding.

[0057]

As described above, according to the present invention, the reflected light passing through the liquid crystal layer is condensed on the emission area of the upper space deviating from the liquid crystal screen. It does not interfere with the visibility of the monitor screen by being superimposed on the display information on the screen. That is, the light source is not reflected on the liquid crystal display image, and as a result, the liquid crystal display image can be easily viewed and the visibility can be improved.

[Brief description of the drawings]

FIGS. 1A and 1B are views for explaining an example of a liquid crystal display device according to the present invention, wherein FIG. 1A is a cross-sectional view thereof, and FIG.

FIGS. 2A and 2B are diagrams for explaining the liquid crystal display device shown in FIG. 1, wherein FIG. 2A is a cross-sectional view thereof, and FIG. 2B is a diagram for explaining a relationship between a mirror Fresnel lens center and a distance.

3A and 3B are diagrams for explaining an example of a concavo-convex pattern used in the liquid crystal display device shown in FIG.
FIG. 4 is a diagram illustrating a relationship between a distance (x) from a mirror Fresnel lens center and an inclination angle (θ), and FIG. 4B is a diagram illustrating a relationship between a distance (x) from a mirror Fresnel lens center and a pitch.

FIG. 4 is a view for explaining a position where a mirror Fresnel lens center is defined;

FIGS. 5A to 5D are views for explaining the creation of a stamper used when forming the reflective layer shown in FIG. 1, and FIGS. 5A to 5D are cross-sectional views illustrating steps.

FIGS. 6A to 6D are views for explaining an example when the reflection layer shown in FIG. 1 is formed, and FIGS. 6A to 6D are cross-sectional views illustrating steps.

FIGS. 7A to 7D are views for explaining another example when the reflection layer shown in FIG. 1 is formed, and FIGS. 7A to 7D are cross-sectional views illustrating steps.

FIGS. 8A to 8D are views for explaining still another example when the reflective layer shown in FIG. 1 is formed, and FIGS. 8A to 8D are cross-sectional views illustrating steps.

9A and 9B are views for explaining another example of the liquid crystal display device according to the present invention, wherein FIG. 9A is a cross-sectional view thereof, and FIG. 9B is a view of the Fresnel lens layer as viewed from above.

10A and 10B are views for explaining the liquid crystal display device shown in FIG. 9, wherein FIG. 10A is a cross-sectional view and FIG. 10B is a view for explaining the relationship between the center of the Fresnel lens and the distance.

11 is a diagram for explaining an example of a concavo-convex pattern used in the liquid crystal display device shown in FIG.
(A) is a diagram showing the relationship between the distance (x) from the center of the Fresnel lens and the inclination angle (θ), and (b) is a diagram showing the relationship between the distance (x) from the center of the Fresnel lens and the pitch.

12A and 12B are diagrams for explaining an example of a conventional liquid crystal display device, in which FIG. 12A is a cross-sectional view and FIG. 12B is a diagram illustrating a relationship between a reflection angle and brightness.

13 is a diagram for explaining the liquid crystal display device shown in FIG. 12, (a) is a cross-sectional view thereof, and (b) is a diagram showing a relationship between a panel position and brightness.

14A and 14B are diagrams for explaining another example of the conventional liquid crystal display device, where FIG. 14A is a cross-sectional view, FIG. 14B is a diagram showing the relationship between panel position and brightness, and FIG. 14C is Fresnel. It is the figure which looked at the lens from the top.

[Explanation of symbols]

 Reference Signs List 2 upper substrate 3 light diffusion plate 4, 34 reflection film 5 focal point 7 Fresnel lens layer 8 resin layer 8A reflection layer (mirror Fresnel lens layer) 9 light source (sun) 11 lower substrate 12A, 12B liquid crystal panel 24 stamper 35 color Filter substrate (CF) 38 Liquid crystal layer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shigeru Aoyama 801 Minami-Fudo-do-cho, Higashi-iri, Horikawa, Shiokoji-dori, Shimogyo-ku, Kyoto F term (reference) 2H042 DA02 DA04 DA11 DB08 DC02 DC08 DD02 DE00 2H091 FA14Z FA16Z FA27Z FA31X FD04 FD06 LA03 LA16

Claims (7)

[Claims] 1. A liquid crystal display device in which a liquid crystal layer is illuminated with incident light incident on the surface of a display panel from the outside to display a liquid crystal screen, wherein the incident light incident on the display panel from a vertical direction. Is provided through the liquid crystal layer, is reflected, and is condensed to an emission area in an upper space of the display panel, and a vertical line drawn from the emission area to a plane including the display panel is provided on the display panel. And a liquid crystal display device which does not intersect with the liquid crystal display device. 2. The display panel according to claim 1, wherein a diffusion plate is provided on a surface of the display panel, and the light condensing unit has a reflection layer provided below the liquid crystal layer. The liquid crystal display device according to claim 1, wherein a surface on a layer side has an uneven pattern for directing the reflected light toward the emission region. 3. The light condensing means has a reflection layer provided below the liquid crystal layer and a lens layer provided above the liquid crystal layer, wherein the lens layer is provided with the liquid crystal layer. 2. The liquid crystal display device according to claim 1, wherein a surface opposite to the layer has a concavo-convex pattern directed to the emission region. 4. The liquid crystal according to claim 3, wherein a diffusion layer for diffusing light is formed above the liquid crystal layer, and the lens layer is disposed on the diffusion layer. Display device. 5. The uneven pattern has a plurality of convex portions having an inclined surface, and the inclination angle of the inclined surface intersects a perpendicular line drawn from the emission area to a plane including the display panel. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is formed so as to increase as the distance from the point increases. 6. The projection / recess pattern has a plurality of projections each having an inclined surface, and a pitch at which the projections are formed while keeping the height of the projections of the inclined surface constant is from the emission area to the display area. The liquid crystal display device according to claim 2, wherein a perpendicular drawn on a plane including the panel is formed so as to become finer as it goes away from a point intersecting the plane. 5. 7. The liquid crystal display device according to claim 1, wherein the center of the emission area is positioned on a line segment bisecting the liquid crystal screen.