JP7257097B2 - liquid crystal display - Google Patents

Description

The present invention relates to a liquid crystal display device including a curved liquid crystal display panel.

Conventionally, a liquid crystal display (LCD) includes, for example, a TFT array side substrate on which a large number of pixel electrode portions including thin film transistor elements are formed, a color filter and a color filter on which a black matrix is formed. It has a liquid crystal display panel in which the side substrates are opposed to each other, the substrates are bonded together at a predetermined interval, and liquid crystal is filled and sealed between the substrates. In general, the color filter side substrate forms a vertical electric field to be applied to the liquid crystal between the pixel electrodes and the entire main surface (first main surface) facing the TFT elements and the pixel electrodes. A reference electrode (common electrode) is formed for this purpose. Furthermore, red (R), green (G), and blue (B) color filters corresponding to the respective pixels are formed on the first main surface of the color filter side substrate, and light passing through the respective pixels is formed. A black matrix that prevents light from interfering with each other is formed so as to surround the periphery of the color filter.

Such an LCD is provided with a backlight device on the back side opposite to the viewer's side, through which transmitted light for forming an image on the liquid crystal display panel is incident from the back side of the liquid crystal display panel. There are two methods for this backlight device. One method is an edge light method in which LED (Light Emitting Diode) elements as light emitting elements are arranged on the end surface of the light guide plate. In this edge light method, light from LEDs arranged at the edge of the screen area of the liquid crystal display panel is guided to the entire screen by a light guide plate and dispersed uniformly. The edge light method can maintain good optical uniformity on a screen of up to about 60 inches, and can realize a backlight device with a thickness of about 5 to 10 mm.

Another method is a direct-type method, which is a method in which LED elements are arranged directly under the screen area of the liquid crystal display panel and light from the LED elements is made incident on the pixels. This direct type system has no limitation on the screen size of the liquid crystal display panel to which it is applied, and has low power consumption and good heat dissipation. In addition, the backlight device of the direct type tends to be thicker than that of the edge light type, but the thickness can be suppressed to about 10 mm or less.

In general, liquid crystal display devices have rectangular liquid crystal display panels arranged in a plane to form a flat panel display. The conventional liquid crystal display device shown in FIG. 5 has a direct type backlight in which a light source element 4 is arranged to face the rear surface of the liquid crystal display panel 1 . The backlight is composed of aligned light source elements 4 and a light source substrate 5 for supplying signals to the light source elements. A liquid crystal display panel 1 is arranged above the backlight, which is the surface side, and the liquid crystal display panel 1 is adhesively fixed to a transparent support 2 having a curved surface with an arrow A in the figure as a curved axis. there is The transparent support 2 is a plate-like body such as a glass substrate, and has a curved shape protruding toward the back side. The liquid crystal display panel 1 has a curved shape along the curved shape of the transparent support.

JP-A-2005-91873

FIG. 4 is an enlarged view in which the light source element 4 is enlarged. An LED package 11 as a light source element is connected and arranged on the light source substrate 5 . The LED package 11 has an LED element 12 in its central portion, and emits light from the upper surface of the LED element 12 . Depending on the type of the LED element 12, there are also those in which a phosphor is arranged. The light emitted from the LED element 12 is emitted at various light irradiation angles θ from the light irradiation surface 13 of the LED package. Among them, the light irradiated at the widest angle is the light irradiation maximum angle θm. When the light irradiated at the maximum light irradiation angle θm is directed to the curved end portion of the laminate 3 shown in FIG. surface brightness may decrease. That is, the luminance of the liquid crystal display device becomes non-uniform, which may adversely affect the liquid crystal display. The arrow indicated by B in FIG. 5 conceptually indicates the density of the irradiation light.

SUMMARY OF THE INVENTION The present invention has been completed in view of the above problems, and an object thereof is to realize uniform surface luminance and good liquid crystal display in a curved liquid crystal display device.

The liquid crystal display device of the present invention comprises a liquid crystal display panel having polarizing plates laminated on the front side and the back side respectively, a transparent support on which the liquid crystal display panel is laminated and arranged , and a liquid crystal display on the back side of the transparent support. and a light source substrate on which a plurality of light source elements are arranged, wherein the transparent holder has a curved shape so as to protrude toward the back surface side, and the liquid crystal display panel is provided on the front surface of the substrate. The thickness including the polarizing plate on the side and the polarizing plate on the back side is thinner than the thickness of the transparent support and has a shape corresponding to the curved shape of the transparent support, and the entire surface on the side of the transparent support. is fixed to the transparent holder to form a curved laminated body, the plurality of light source elements are arranged to face the back surface of the transparent holder, and the unit is positioned at the curved end of the transparent holder The number of light source elements per area is larger than the number of light source elements per unit area positioned at the center of the curve of the transparent holder, and the liquid crystal display panel is arranged on the surface side of the transparent holder. is characterized by By adopting such a configuration, the luminance at the curved end portion of the liquid crystal display increases, and a flat display can be obtained.

The liquid crystal display device of the present invention is preferably characterized in that the liquid crystal display panel is placed on the surface side of the transparent holder. By arranging the liquid crystal display panel on the observer's side, the sense of depth of the liquid crystal display is eliminated, and a clear liquid crystal display can be realized.

Further, in the liquid crystal display device of the present invention, preferably, the plurality of light source elements are aligned, and the number of light source elements in the outermost row located at the curved end portion is larger than the number of light source elements in other rows. It is characterized by many By arranging a large number of light source elements in the outermost row, it is possible to more easily control the brightness at the curved end.

Further, the liquid crystal display device of the present invention comprises a liquid crystal display panel in which polarizing plates are laminated on the front side and the back side, respectively, a transparent support on which the liquid crystal display panel is laminated and arranged , and a back side of the transparent support. and a light source substrate on which a plurality of light source elements are placed, wherein the transparent holder has a curved shape so as to protrude toward the back side, and the transparent holder includes: The thickness of the liquid crystal display panel including the polarizing plate on the front side and the polarizing plate on the back side is thinner than the thickness of the transparent support, and the entire surface of the liquid crystal display panel on the side of the transparent support is fixed to form a curved laminate. is formed, the light irradiation amount of the curved end portion on the back surface of the laminate is larger than the light irradiation amount of the curved central portion, and the liquid crystal display panel is arranged on the front surface side of the transparent holder. and By adopting such a configuration, the luminance at the curved end portion of the liquid crystal display increases, and a flat display can be obtained.

The liquid crystal display device of the present invention is preferably characterized in that the liquid crystal display panel is placed on the surface side of the laminate. By arranging the liquid crystal display panel on the observer's side, the sense of depth of the liquid crystal display is eliminated, and a clear liquid crystal display can be realized.

The liquid crystal display device of the present invention is preferably characterized in that the plurality of light source elements are arranged facing the rear surface of the laminate.

INDUSTRIAL APPLICABILITY The liquid crystal display device of the present invention can maintain uniform display luminance and realize uniform display even if it is a curved liquid crystal display device.

FIG. 1 is a view showing one embodiment of the liquid crystal display device of the present invention, and is a conceptual cross-sectional view of the liquid crystal display device. FIG. 2 is a plan view showing an example of arrangement of light source elements in the liquid crystal display device of the present invention. FIG. 3 is a plan view showing another example of arrangement of light source elements in the liquid crystal display device of the present invention. FIG. 4 is an enlarged cross-sectional view of the light source element. FIG. 5 is a conceptual cross-sectional view of a conventional liquid crystal display device.

Hereinafter, embodiments of the liquid crystal display device of the present invention will be described with reference to the drawings. However, each figure referred to below shows the main part for explaining the liquid crystal display device of the present invention among the constituent members in the embodiment of the liquid crystal display device of the present invention. Accordingly, the liquid crystal display device according to the present invention may include well-known structural members such as an optical sheet and a light guide plate, which are not shown in the drawings. 1 to 4 showing the configuration of the liquid crystal display device of the present invention, the same parts as in FIG. 5 showing the configuration of the conventional liquid crystal display panel are denoted by the same reference numerals, and detailed description thereof will be omitted. .

FIG. 1 is a view showing one embodiment of the liquid crystal display device of the present invention, and is a conceptual cross-sectional view of the liquid crystal display device. The liquid crystal display panel 1 of the present invention has an array-side substrate, a color filter-side substrate, liquid crystal sandwiched between the substrates, and a sealing member surrounding the liquid crystal and joining the substrates. A polarizing plate is arranged on the outside of both substrates.

The liquid crystal display panel 1 is fixed to a curved transparent holder 2 so as to protrude on the back side, and the liquid crystal display panel also has a curved shape along the transparent holder 2 . The liquid crystal display panel 1 and the transparent support 2 are fixed with an adhesive layer. The adhesive layer may be arranged on the entire surface of the liquid crystal display panel, or may be arranged partially on the periphery. Also, the transparent support 2 may be a glass substrate or a resin body such as an acrylic resin. In the present invention, the transparent holder is curved, and the liquid crystal display panel 1 is aligned with the curved transparent holder 2 to form the laminated body 3. Laminate 3 may be formed along holding body 2 . Considering that the rigidity of the member to be curved is higher than that of the member to be curved, the rigidity is increased by the transparent resin body 2, which has a high degree of freedom in material selection, and the liquid crystal display panel is aligned by curving. is preferred. At this time, it is preferable that both substrates of the liquid crystal display panel are slimmed to facilitate bending. Both substrates preferably have a thickness of 0.3 mm to 0.1 mm.

Further, although the laminate 3 has the liquid crystal display panel 1 on the front side and the transparent holder 2 on the back side, the transparent holder may be arranged on the front side and the liquid crystal display panel on the back side. At this time, if tempered glass is used as the transparent support, it also functions as a cover glass. When used as a cover glass, it is preferable to form an antireflection film or an antifouling film on the surface side. From the viewpoint of good aesthetics of the liquid crystal display, it is preferable to dispose the liquid crystal display panel 1 on the surface side. As the distance between the viewer and the liquid crystal display surface increases, the depth of the display increases, making it difficult to see the display clearly.

The arrow indicated by A in FIG. 1 is the bending axis, which indicates bending in the axial direction. Along this axial direction A, it curves toward the back side. The degree of curvature is preferably a radius of curvature R of 1000 mm to 100 mm. As the radius of curvature R becomes smaller, the amount of light emitted from the curved end portion tends to decrease. Therefore, it is preferable not to make the radius of curvature R too small in terms of surface uniformity of luminance. The area shown in the lower part of FIG. 1 shows the parts in the direction of the bending axis A, with the part positioned at the center being the bending central part C and the part positioned at the end being the curved end E. As shown in FIG.

In the present invention, the number of optical elements 4 per unit area positioned at the curved end portion E is greater than the number per unit area positioned at the curved central portion. In other words, the light irradiation amount of the curved end portion E on the back surface of the laminate 3 is made larger than the light irradiation amount of the curved central portion. By increasing the amount of light irradiation at the curved end portion in this manner, the light emitted from the laminate 3 can be made uniform. The backlight with which the laminated body 3 is irradiated may be a direct type backlight or a sidelight type backlight. When a sidelight type backlight is used, in order to increase the amount of light irradiated from the position of the curved end portion, the light scattering means of the light guide plate should be arranged in only that portion. Moreover, per unit area may be per square centimeter, or per 10 square centimeters in some cases. It may be appropriately determined according to the size of the light source substrate and the density of the optical elements.

FIG. 2 shows an arrangement example of the optical elements 4 arranged on the light source substrate 5 . FIG. 2 is shown as a plan view and the laminate 3 has its bending axis in the direction of arrow A in the figure. The end portion side in the direction of the curve axis is the curved end portion, and the number of light source elements 4 located at the curved end portion is greater than the number of light sources located at the center portion of the curve. By increasing the number of light source elements 4 positioned at the curved end portions in this manner, the amount of light irradiation to the curved end portions on the back surface of the laminate can be increased.

FIG. 3 shows another arrangement example of the optical elements 4 arranged on the light source substrate 5 . FIG. 3 is a plan view, and the laminate 3 has an axis of curvature A shown in the horizontal direction of the drawing. The light source elements are arranged vertically and horizontally. The number of optical elements 4 in the outermost row at the end of the optical substrate 5 in the direction of the bending axis A is greater than the number of optical elements 4 in the other rows. By arranging a large number of the optical elements 4 in the outermost row in this manner, the amount of light irradiation at the curved end portion on the back surface of the laminate 3 can be increased, and the light emitted from the surface of the laminate can be efficiently emitted. can be well controlled.

Although the bending axis A shown in the drawing shows only one direction, it may have a bending axis in a direction perpendicular to the bending axis A in the left-right direction, or may have two bending axes perpendicular to each other. Also good. In the case of having two curved axes, it is preferable that the number of light source elements 4 positioned at the curved ends of each axis is greater than the number of light source elements 4 located at the curved central portion.

Further, in the liquid crystal display device of the present invention, it is preferable to arrange a diffusion film or a brightness enhancement film between the laminate and the light source element 4 . Such films are preferably adhered and fixed along the curved surface of the laminate 3 . Providing a light reflecting layer on the surface side of the light source substrate 5 is also preferable for reuse of light.

It should be noted that the liquid crystal display panel of the present invention is not limited to the above-described embodiments, and appropriate design changes and improvements may be made. For example, the light source substrate 5 may not be rectangular, but may be circular or elliptical, and the liquid crystal display panel may also be non-rectangular. Also, the light source element need not be an LED package as long as it can irradiate light.

The liquid crystal display panel of the present invention can be applied to various electronic devices. The electronic devices include digital display watches such as smart watches, automobile route guidance systems (car navigation systems), ship route guidance systems, aircraft route guidance systems, smartphone terminals, mobile phones, tablet terminals, and personal digital assistants (PDAs). , video cameras, digital still cameras, electronic notebooks, electronic books, electronic dictionaries, personal computers, copiers, terminal devices for game machines, televisions, product display tags, price display tags, industrial programmable display devices, car audio systems, Head-up displays, digital audio players, facsimiles, printers, copiers, automated teller machines (ATMs), vending machines, Head Mounted Display devices (HMD), in-vehicles such as trains Advertisement displays, etc.

1 liquid crystal display panel 2 transparent holder 3 laminate 4 light source element 5 light source substrate 11 LED package 12 LED element 13 LED package irradiation surface

Claims (4)

A liquid crystal display panel in which polarizing plates are laminated on the front side and the back side, respectively;
a transparent holder on which the liquid crystal display panel is laminated and arranged ;
A liquid crystal display device including a light source substrate disposed on the back side of the transparent holder and having a plurality of light source elements mounted thereon,
The transparent holder has a curved shape so as to protrude on the back side,
The liquid crystal display panel has a thickness including the polarizing plate on the front side and the polarizing plate on the back side, which is thinner than the thickness of the transparent holder and has a shape corresponding to the curved shape of the transparent holder. The entire body-side surface is fixed to the transparent holder to form a curved laminated body,
The plurality of light source elements are arranged to face the back surface of the transparent holder, and the number of light source elements per unit area positioned at the curved end of the transparent holder is located at the curved central portion of the transparent holder. more than the number of light source elements per unit area
A liquid crystal display device, wherein the liquid crystal display panel is disposed on the surface side of the transparent holder . 2. The light source element according to claim 1 , wherein the plurality of light source elements are aligned, and the number of light source elements in the outermost row located at the curved end is larger than the number of light source elements in other rows. Liquid crystal display. A liquid crystal display panel in which polarizing plates are laminated on the front side and the back side, respectively;
a transparent holder on which the liquid crystal display panel is laminated and arranged ;
A liquid crystal display device including a light source substrate disposed on the back side of the transparent holder and having a plurality of light source elements mounted thereon,
The transparent holder has a curved shape so as to protrude on the back side,
The entire surface of the liquid crystal display panel on the side of the transparent support is fixed to the transparent support, and the thickness including the polarizing plate on the front side and the polarizing plate on the back side is thinner than the thickness of the transparent support. A curved laminate is formed by
The amount of light irradiation at the curved end portion on the back surface of the laminate is larger than the light irradiation amount at the curved central portion,
A liquid crystal display device, wherein the liquid crystal display panel is disposed on the surface side of the transparent holder . 4. The liquid crystal display device according to claim 3 , wherein the plurality of light source elements are arranged to face the rear surface of the laminate.

Images