JPS63261383A - Display panel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applicable to liquid crystal display devices, plasma display devices, light emitting diode display devices, EL (electroluminescence) display devices, electrochromic display devices, fluorescent display tube devices, etc. The present invention relates to a display panel device in which display units are arranged in a matrix, and particularly to a display panel device having a large screen.

(Prior art and its problems) In a display panel device in which display units are arranged in a matrix, seals, etc. that are disposed at the joints of signal electrodes and scanning electrodes and the joints of display units are present.
A grid-like non-display line appears between display units. Since this non-display gap occurs over a large width, especially when displaying a large screen, the screen is divided into a grid pattern and the image is displayed in a mosaic pattern.

Therefore, it has been proposed to prevent the occurrence of blank lines by covering the periphery of the liquid crystal display unit with an expensive light guide made up of tens of thousands of optical fibers (Japanese Patent Laid-Open No. 185785/1983). (see publication). However, this method of using light guides requires a large number of light guides when the number of liquid crystal display units increases, which makes the display panel device very expensive, and it is difficult to arrange each light guide. It is not practical as it involves technical difficulties. In addition, in this method, there are two types of output light: the output light that travels straight through the light guide and the output light that is totally reflected between the light guides, but since the directional characteristics of these total output lights are narrow, the light guide Only the portion of the image viewed from the front direction becomes brighter. Therefore,
When the image is viewed from an oblique direction, the image becomes dark, and as the angle increases, it becomes impossible to visually recognize the image.

That is, the viewing angle becomes small. In addition, the directional characteristics of the light that travels straight through the light guide and exits are narrower, so
When each pixel outputs R, G, and B color light to perform color display, the hue may shift depending on the viewing angle due to the difference in relative position of each R, G, and H pixel and the light guide.

By the way, it is theoretically possible to increase the viewing angle by designing a display panel device by optically considering the light entrance and exit surfaces, length dimensions, and installation position relative to the light source of each light guide. be. However, it is actually necessary to individually process the light entrance surface of each light guide, so when using a large number of light guides, the process requires a lot of time and effort, making it extremely difficult. It accompanies me.

It has also been proposed to enlarge and project a transmissive liquid crystal display unit onto a transmissive scattering plate using a point light source corresponding to each pixel to prevent the occurrence of blank lines including the frame portion of each display unit (especially (Refer to 1988-138288).

However, this method cannot be applied to display panel devices other than transmissive display panel devices, and since the external light passes through the transmission scattering plate and illuminates the frame, the frame is exposed to the screen by the external light. There is a risk that it will be displayed. If the transmission scattering plate is made of a highly transparent material, the image on the transparent scattering plate and the image displayed on the liquid crystal display unit may overlap, resulting in double images.

Furthermore, the light diffusion directional characteristics of the transparent scattering plate are not flat with respect to the viewing angle, and light rays from a point light source are incident on the transparent scattering plate along the radial direction. For this reason, when the screen is viewed from an oblique direction, the brightness in the vicinity of the joining portion of adjacent projected images differs around the joining line, resulting in an image having brightness and darkness.

By manufacturing a transmission-scattering plate with a large amount of light-expanding substance mixed in, or by coating the surface of the transmission-scattering plate with the substance, the light diffusion directional characteristics can be made flat to some extent with respect to the viewing angle. . However, in this case, the light transmittance of the transmission-scattering plate decreases, making the image darker overall, and the transmission-scattering plate appears to have a white color that stands out due to the extraneous light. Contrast decreases.

By the way, the above-mentioned point light source needs to have a sufficiently small light emitting point, output white light with high brightness, and have low power consumption and reliability. However, such an ideal point light source does not currently exist.

In addition, when increasing the number of liquid crystal display units to configure a large screen, many point light sources are also required, so mutual positioning accuracy of the point light sources, liquid crystal display units, and transmission scattering plates is required. In addition, the display panel device becomes expensive, and since point light sources generally have variations in luminous intensity, countermeasures require advanced technology. Since the structure becomes complicated, there is a risk that the display panel device will become more expensive.

Furthermore, in a transmissive liquid crystal display panel device, a part of a collimator is provided between the light source and the display panel, and a microlens is provided in the front of the display panel corresponding to each pixel, thereby increasing the viewing angle. (See Japanese Unexamined Patent Publication No. 61-284731). However, the microlens used in this method is usually made of transparent resin such as PMMA resin, polycarbonate, or polystyrene, so it has a thermal expansion coefficient and hygroscopic expansion relative to the glass plate on which the liquid crystal is arranged. The coefficients will differ greatly.

For this reason, the relative position of the microlenses placed corresponding to each pixel will shift significantly due to changes in temperature and humidity, resulting in uneven viewing angles and, in the case of color display, color shift. Image quality will deteriorate. Furthermore, since the microlens is arranged such that the convex curved surface is located on the viewer's side, the incident light is totally reflected on the curved surface, and the light diffusion directional characteristics are significantly narrowed.

Therefore, the viewing angle is not so large and is estimated to be within a range of about 35 degrees with respect to the perpendicular to the screen.

By the way, when manufacturing microlenses industrially, it is common to place a heated and softened transparent resin plate in a mold having a predetermined shape and press the mold. Therefore, in order to manufacture a large display panel device, it is necessary to provide a large mold with a large number of concave curved surfaces corresponding to the large number of convex curved surfaces. However, there is a limit to the size of the mold, and it is technically difficult to provide a large number of concave curved surfaces with high precision in correspondence with each pixel.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and includes a convex portion having a substantially arcuate cross section on the surface facing the display units arranged in a matrix. Another object of the present invention is to provide a display panel device having a lenticular plate in which concave portions are continuously provided along the vertical direction.

(Embodiments of the Invention) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The display panel device according to the present invention includes an image panel l, as shown in FIGS. 2 and 3.

This image panel 1 is composed of a plurality of liquid crystal display units 2 arranged in a matrix, and each liquid crystal display unit 2 is arranged at a pitch of P+ in the horizontal direction. A grid-like non-display line 3.3 is formed between these liquid crystal display units 2.
' has occurred. As shown in FIG. 4, each liquid crystal display unit 2 has a pair of glass plates 4.5 arranged in parallel and facing each other, with a sealing material 6 interposed between these glass plates 4.5. A liquid crystal 7 is sealed therein. A plurality of signal electrodes 8 are provided on the inner wall surface of one glass plate 4, and color filters R (red), G (green), and B (blue) are mounted on each signal electrode 8, respectively. A scanning electrode 9 is provided on the inner wall surface of the other glass plate 5, and this scanning electrode 9 is connected to the scanning electrode 9 of another adjacent liquid crystal display unit 2 via a lead wire 10. Polarizing plates 11 are provided on the outer wall surfaces of both glass plates 4.5.

A fluorescent lamp 12 is arranged on the back side of the image panel 1. Therefore, since the liquid crystal 7 performs a shutter operation by supplying a control signal to the signal electrode 8, the light output from the fluorescent lamp 12 is controlled by the liquid crystal 7, and the brown filters R, G,
When H is transmitted, it is output as colored light. Thus, a color image is formed.

Each liquid crystal display unit 2 is mutually joined by a crosspiece 13 extending in the vertical direction and a crosspiece (not shown) extending in the horizontal direction, and is held and fixed in a matrix. The vertical bars 13 are the cause of the above-mentioned non-display line 3, and the horizontal bars are the cause of the above-mentioned non-display line 3'.

Note that in the liquid crystal display unit 2, since the spacing between the signal electrodes 8 can be made minute, there is no need to consider the non-display lines that occur between the signal electrodes 8.

Now, on the front surface of the image panel l, lenticular plates 14 are arranged at a distance of d. As shown in FIGS. 1, 2, and 4, this lenticular plate 14 has a plurality of convex lenticules 14a continuously provided in the vertical direction on the surface facing the liquid crystal display unit 2. There is. These lenticules 14a are as shown in FIG.

They are provided at a pitch of P2, and have an arcuate cross section with a radius of curvature of γ and a tangent angle of θ.

The lenticular plate 14 is mixed with an appropriate amount of a light-multiplying substance.

The operation of the display panel device of the present invention having the above configuration will be explained with reference to FIG.

That is, the outer end of the color filter H becomes invisible when the viewer is positioned to the left of the broken line in (a) when the lenticular plate 14 is not present, and the inner end of the color filter R becomes invisible as shown in (b).
It becomes invisible if it is located to the left of the dashed line. In other words,
Red light is attenuated between dashed lines (a) and (b), and the red light is attenuated between dashed lines (a) and (b).
Red light is not output to the left of b). Therefore, the viewing angle becomes small, resulting in an image with imbalanced color balance for the viewer located on the left side.

On the other hand, when the lenticular plate 14 is provided, the red light is refracted by the lenticular plate 14.
The outer edge of the color filter R can also be seen at the two-dot chain line position in (c),
The inner end can also be seen at the solid line position (d). Therefore, even if a liquid crystal having a small viewing angle, such as a twisted nematic liquid crystal, is used, the viewing angle in the lateral direction can be greatly improved.

Further, the colored light reflected from any point on the crosspiece 13 is refracted by the curved surface of the lenticular plate 14a, and further refracted by the front surface of the lenticular plate 14, so that it is impossible to form a virtual image or a real image of the crosspiece 13. will be scattered. Therefore, it is possible to reliably prevent the non-display line 3 from occurring along the vertical direction.

Since the lenticular plate 14 contains an appropriate amount of light multiplier material, the vertical viewing angle is improved without darkening the screen, and the horizontal non-display line 3' is prevented from occurring. be able to. Note that a similar effect can be obtained by applying a light-multiplying substance to the surface of the lenticular plate 14.

By the way, the lenticular 14 of the lenticular plate 14
Since it is not necessary to provide a corresponding to the signal electrode 8 of each pixel, and it is sufficient to simply form the cross section into an arc shape, processing precision is not required. Therefore, a heated and softened resin plate is roll-formed. It can be manufactured by Therefore, the lenticular plate 14 can be manufactured easily and with good workability to accommodate a large screen, and the structure is simplified. Moreover, even if the relative position between the lenticular plate 14a of the lenticular plate 14 and the pixel changes, the visible angle will not be unevenly distributed or color shift will not occur.

The colored lights from the respective color filters R, G, and B are refracted and diffused by the lenticular plate 14 and mixed together.
Each colored light is not visually recognized separately, so the stripes of the three primary colors appear natural and smooth on the screen. Therefore, a display panel device that is inexpensive, easy to manufacture, and has excellent image quality can be obtained.

FIG. 5 shows a lenticular plate 14 according to another embodiment of the invention. That is, this lenticular plate 14
A plurality of lenticules 14b are also provided on the surface opposite to the surface on which the lenticules 14a are provided, that is, on the front surface. These lenticules 14b are provided along the horizontal direction orthogonal to the lenticular 14a. Therefore, it is possible to prevent the horizontal non-display line 3' (see FIG. 3) from occurring when the vertical viewing angle is improved. Therefore, there is no need to mix or apply a light-multiplying substance to the lenticular plate 14 of this embodiment. The lenticular plate 14 is formed by pasting together a pair of roll-formed lenticular plates with a small thickness so that the lenticules are perpendicular to each other, or by simply placing a pair of lenticular plates to face the liquid crystal display unit 2 so that the lenticules are perpendicular to each other. It can be configured by

In the above embodiment, the lenticules 14a and 14b of the lenticular plate 14 may be formed into concave portions having a substantially arc-shaped cross section, and the curved surface shapes of the lenticular plates 14a and 14b may be different, in short, the width of the non-display line, etc. It may be selected appropriately in consideration of the desired image and processability.

Further, if an anti-reflection film is provided on the surface of the lenticular plate 14 to prevent reflection of visible light, the image becomes clearer. Furthermore, the lenticular plate 14 may be colored to obtain an image according to the purpose or preference.

Further, fine irregularities may be provided on the surface of the lenticular plate 14 to improve the light diffusion effect.

It goes without saying that the present invention can also be applied to other display panel devices such as plasma display devices, light emitting diode display devices, EL display devices, electrochromic display devices, and fluorescent display tube devices.

(Effects of the Invention) According to the present invention, the lenticular plate has convex portions or four portions having a substantially arc-shaped cross section continuously provided in the vertical direction on the surface facing the display units arranged in a matrix. As a result, the viewing angle is greatly improved and the occurrence of non-display lines can be prevented. In addition, since lenticular plates do not require high processing precision, they can be easily manufactured by roll forming or heat press forming, and even if the lenticular plate is misaligned with respect to the pixel, the visible angle will be unevenly distributed or color shift will occur. It never occurs. Therefore, it is possible to provide a display panel device that has a simple structure, is easy to manufacture, and has excellent image quality at a low cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a lenticular plate according to the present invention, and FIG.
3 and 3 are a sectional view and a front view of a display panel device according to the present invention, FIG. 4 is an enlarged sectional view of the main part of FIG. 2, and FIG. 5 is a lenticular plate according to another embodiment of the present invention. FIG. 2... Liquid crystal display unit, 3.3'... No display line, 8... Signal electrode, 13... Crosspiece, 14... Lenticular plate, 14a, 14b... Lenticular. Figure 1 Figure 2 Figure 3

Claims (5)

[Claims] (1) In a display panel device including a plurality of display units arranged in a matrix, a convex portion or a concave portion having a substantially arcuate cross section is continuously provided in the vertical direction on a surface facing the display unit. A display panel device characterized by having a lenticular plate. (2) The display according to claim 1, wherein the lenticular plate has convex portions or concave portions having a generally arcuate cross section continuously provided in the horizontal direction on the opposite surface. Panel device. (3) The display panel device according to claim 1 or 2, wherein the lenticular plate is provided with an anti-reflection film for preventing reflection of visible light on the plate surface. (4) The display panel device according to any one of claims 1 to 3, wherein the lenticular plate is colored. (5) The display panel device according to any one of claims 1 to 4, wherein the lenticular plate is mixed with or coated with a light-multiplying substance, or has minute irregularities on the plate surface. .