JP2012173466A - Image displaying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of increased costs for an image displaying device configured to dispose a multiple of displaying elements such as LED, in which a pixel pitch is shortened as resolution becomes higher and there is a need to align pixels at high density, and the costs increases because the number of LEDs per unit area increases, and the problem of remarkably increasing costs when realizing high-densification of an LED array in a displaying device that uses a 3in1 element containing the 3 primary colors of R, G, B within 1 element and that is mainly used in-house in applications with a short visual distance.SOLUTION: In an image displaying device having a display part constructed by arranging pixels consisting of light-emitting elements in a grid shape, the display part is constructed by allocating a 3in1 element 2b containing the 3 primary colors R, G, B to at least 1 pixel out of 4 pixels of a base grid (square lattice) 1 composed of 4 pixels of 2×2 and allocating a monochrome light-emitting element 2a to remaining pixels to form a pattern of the base grid, and repeatedly arranging the base grid in a grid shape.

Description

  The present invention relates to an image display apparatus having a display unit configured by arranging a large number of light emitting elements such as light emitting diodes (LEDs) as pixels.

  FIG. 9 shows a general image display apparatus which is an object of the present invention. The image display apparatus 10 includes a display unit 4 configured by arranging a large number of display units 5 vertically and horizontally. Each display unit 5 is configured by arranging pixels 2 made of light emitting elements such as LEDs in a grid, and further, the display unit 4 is formed by arranging the display units 5 in a grid. FIG. 9B shows an enlarged view of a part of the pixel group 3 of the display unit 5.

  Conventionally, in order to display a full-color image, a large image display device forms a display unit by arranging pixels including at least one R, G, and B LED elements as pixels. Since the LED elements can be arbitrarily designed with respect to the arrangement and arrangement pitch of the three primary colors, in recent years, it has become possible to construct image display devices having various resolutions and luminances according to applications. Recently, an element called 3in1 in which LED chips of three colors of R, G, and B are accommodated in one LED lamp has appeared.

  When such a 3in1 type LED element is arranged as a pixel, one pixel emits three primary colors, so that it becomes easier to mix three colors as compared with a system in which three LEDs of R, G, and B are arranged. For this reason, the viewing distance when the viewer looks at the image is reduced. As for such a 3in1 type LED element arrangement, there is a system as shown in the following document.

JP 2001-75508 A JP-A-10-254386 JP 2009-230096 A

  In the conventional image display device, in order to increase the resolution, it is necessary to reduce the pitch of the pixel arrangement and arrange the pixels at high density. For this reason, in the high-resolution large-sized image display apparatus, the number of LED elements used per unit area increases, and the cost increases. In particular, in applications such as high-definition, where high-definition content is displayed with high image quality, the arrangement of LED elements is increased in density, resulting in a dramatic increase in cost.

  In recent years, the use of a 3 in 1 element as shown in Patent Document 1 is increasing as an application having a short viewing distance mainly in an indoor area, and the cost is particularly high when the arrangement of LED elements is increased. The rise was significant. On the other hand, as a method for optimizing the arrangement of LED elements in order to reduce costs, a method using white LED elements as in Patent Document 2 and a decrease in image quality as in Patent Document 3 are minimized. However, a method for reducing the number of LED elements has been proposed.

  In view of the above points, the present invention is intended to provide an image display device capable of high-quality display while suppressing an increase in cost.

  The image display device according to the present invention is an image display device having a display unit configured by arranging pixels made of light emitting elements in a grid pattern, and includes 4 pixels of a basic grid (square grid) made up of 2 × 2 pixels. A display unit is configured by repeatedly arranging a basic grid of a pattern in which 3in1 elements including three primary colors of R, G, and B are allocated to at least one pixel and a single color light emitting element is allocated to the remaining pixels. It is a thing.

  The present invention realizes full color display using 3in1 elements including the three primary colors of R, G, and B, and at the same time, appropriately arranges inexpensive LEDs, while minimizing deterioration in image quality. The cost of the display portion can be greatly reduced, and an inexpensive and high-quality image display device can be provided.

It is a figure which shows the display part of the image display apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the basic | foundation grating | lattice of Embodiment 1 of this invention. It is a figure explaining the arrangement | sequence of the basic lattice of Embodiment 1 of this invention. It is a figure for demonstrating operation | movement of Embodiment 1 of this invention. It is a figure explaining the arrangement | sequence of the basic lattice of Embodiment 1 of this invention. It is a figure for demonstrating the operation | movement of Embodiment 1 of this invention. It is a figure explaining the arrangement | sequence of the basic lattice of the image display apparatus which concerns on Embodiment 2 of this invention. It is a figure for operation | movement description of Embodiment 2 of this invention. It is a perspective view which shows the general large sized image display apparatus used as the object of this invention.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 shows a pixel arrangement of a display unit according to the first embodiment. A display unit 5 includes a large number of pixels (LED elements) 2 arranged in a grid pattern. FIG. 1B shows an enlarged view of the basic grid 1 made up of four 2 × 2 pixels among the pixels constituting the display unit 5. FIG. 2 shows only the basic lattice 1 taken out.

  In the pixel array of the basic lattice (square lattice) 1 according to the first embodiment of the present invention, the three pixels 2a out of the four pixels 2 are LED elements composed of a single color, for example, a white lamp, and the remaining one pixel 2b. Is a 3 in 1 element including the three primary colors of R, G, and B. The display unit 5 is configured by arranging a large number of the basic grids 1 in the vertical and horizontal directions, and the display unit 4 of the large-sized image display device 10 is formed by arranging the display units 5 in a grid pattern. In the basic grid 1, there are four possible positions of the pixel 2b: upper left, upper right, lower left, and lower right. In the present embodiment, the basic grid 1 having the same pattern is repeatedly arranged vertically and horizontally.

FIG. 3 is a diagram in which coordinates are given to the general arrangement of the pixels 2 for explaining the operation of the present invention, and each quadrilateral in the figure indicates one pixel. Assuming that the pixel array pitches in the horizontal direction x and the vertical direction y are x0 and y0, respectively, when the horizontal sampling frequency of the image signal corresponds to the pixel pitch x0 (the vertical direction is y0), The maximum frequency is represented by 1 / 2x0, and the maximum frequency of the image signal that can be similarly restored in the vertical direction is represented by 1 / 2y0.

  FIG. 4 is a two-dimensional representation of this relationship, and shows the spatial frequency characteristics representing the resolution of the pixels 2 arranged in the grid pattern of FIG. In FIG. 4, when the horizontal axis is the horizontal resolution (Cycle / cm) and the vertical axis is the vertical resolution (Cycle / cm), the spatial frequency characteristic of the image that can be expressed is 1 / 2x0 from the center on the horizontal axis. It is represented by a quadrangular region surrounded by a straight line including a point 1 / 2y0 from the center on the axis.

  FIG. 5 shows a case in which 3in1 elements including three primary colors R, G, and B are assigned to one pixel 2b and a white LED lamp is assigned to the remaining three pixels 2a in the basic grid 1 in accordance with the present invention. The pixel array of is shown. The spatial frequency characteristic of the image that can be represented at this time is represented by a double structure as shown in FIG.

  In FIG. 6, when the horizontal axis is the horizontal resolution (Cycle / cm) and the vertical axis is the vertical resolution (Cycle / cm), the spatial frequency characteristics of the image that can be expressed by the white LED element of the pixel 2a are the same as in FIG. Is represented by a quadrangular region surrounded by a straight line including a point 1 / 2x0 from the center on the horizontal axis and 1 / 2y0 from the center on the vertical axis. On the other hand, the spatial frequency characteristics of the image that can be expressed by the 3in1 element of the pixel 2b is a quadrangular region surrounded by a straight line including a point 1 / 4x0 from the center on the horizontal axis and 1 / 4y0 from the center on the vertical axis. expressed. In other words, among the areas represented by the double frame structure in FIG. 6, the surrounding area represented by 1 / 4x0 and 1 / 4y0 can be expressed in full color corresponding to the arrangement of the pixels 2b by 3in1 elements. The outer region represented by 1 / 2x0 and 1 / 2y0 in the surroundings is a region capable of monochrome (monochrome) display corresponding to the arrangement of the white LED lamp of the pixel 2a.

  Since human vision is less sensitive to color changes than light and dark characteristics, monochrome light-emitting elements are responsible for high-resolution areas and 3in1 elements capable of color display for low-resolution areas. A characteristic that matches the visual characteristic is obtained. Of the four display pixels of the basic grid 1, when 3in1 elements including three primary colors of R, G, and B are allocated to one pixel 2b and a single color light emitting element, for example, a white LED element is allocated to the remaining three pixels 2a, When the white LED lamp and 3in1 elements are mixed in the basic grid 1, there is a possibility that grid noise may be noticeable when the screen is viewed from a close distance, but by viewing from an appropriate viewing distance, Such noise is not perceived.

  As a result, a high-resolution display unit can be configured by arranging inexpensive white LED elements at high density, so the display resolution is ensured with an inexpensive white LED lamp, and the color required for full color is With the 3in1 element, a low-cost, high-resolution full-color image display device can be configured.

Embodiment 2. FIG.
FIG. 7 shows a pixel array according to Embodiment 2 of the present invention. In the basic grid 1 composed of 2 × 2 4 display pixels constituting the basic grid, two diagonally positioned pixels 2b have R , G, and B are assigned 3in1 elements, and the remaining two pixels 2a are assigned a single color, for example, a white LED element. The pitches of the pixel arrays in the horizontal direction x and the vertical direction y are x0 and y0, respectively. In the basic grid 1, two positions of the pixel 2b are considered as the lower left and upper right, and the lower right and upper left patterns. In the present embodiment, the basic grid 1 having any one of the same patterns is repeatedly arranged. To do.

  FIG. 8 is a spatial frequency characteristic representing the resolution of an image in the grid pixel array of FIG. In FIG. 8, when the horizontal axis is the horizontal resolution (Cycle / cm) and the vertical axis is the vertical resolution (Cycle / cm), the spatial frequency characteristics of the image that can be expressed by the white LED lamp of the pixel 2a are the same as in FIG. Is represented by a quadrangular region surrounded by a straight line including a point 1 / 2x0 from the center on the horizontal axis and 1 / 2y0 from the center on the vertical axis. On the other hand, the spatial frequency characteristic of an image that can be expressed by the 3in1 element of the pixel 2b is represented by a quadrangular region having a vertex at a point 1 / 2x0 from the center on the horizontal axis and 1 / 2y0 from the center on the vertical axis. .

Comparing the characteristics of FIG. 8 with the characteristics of FIG. 6, the area capable of monochrome display corresponding to the grid arrangement of the white LED lamps represented by the surrounding 1 / 2x0 and 1 / 2y0 is consistent with FIG. 6. . Central
The area capable of full color expression corresponding to the arrangement of 3 in 1 elements is doubled in area corresponding to the doubled number of elements compared to the characteristics of FIG. In addition, the horizontal and vertical resolutions are higher than the diagonal resolutions, corresponding to the arrangement of the pixels 2b of 3in1 elements in a staggered pattern. Since a general image includes more horizontal and vertical components than oblique components, the image quality improvement effect due to the spatial frequency characteristics of FIG. 8 is remarkable.

Embodiment 3 FIG.
In the third embodiment, one or two pixels to which 3in1 elements including three primary colors of R, G, and B are assigned in the basic grid composed of 2 × 2 four pixels in the first or second embodiment. A yellow or green monochromatic light emitting element is assigned to three or two other pixels.

  In the third embodiment, the monochrome display area around the full color display area by the 3in1 elements of FIGS. 6 and 8 is responsible for yellow or green elements. In general, human visibility is high from yellow-green to green. Further, noise on the screen when viewing the screen from a close distance can be avoided by viewing from an appropriate viewing distance. As a result, a high-resolution display unit can be configured by using an inexpensive yellow or green light emitting element.

1 basic grid, 2 pixels,
2a pixel (white element), 2b pixel (3in1 element),
3 pixel group, 4 display section,
5 display unit, 10 image display device.

Claims (4)

  In an image display device having a display unit configured by arranging pixels made of light emitting elements in a grid pattern, at least one of four pixels of a basic grid (square grid) made up of 2 × 2 pixels is R, An image display characterized in that a display unit is configured by repeatedly arranging a basic grid of a pattern in which 3in1 elements including three primary colors of G and B are allocated and a monochromatic light emitting element is allocated to the remaining pixels in a grid pattern. apparatus.   3. A 3in1 element including three primary colors of R, G, and B is allocated to two pixels located diagonally out of the four pixels of the basic grid, and a single color light emitting element is allocated to the remaining two pixels. Item 4. The image display device according to Item 1.   The image display device according to claim 1, wherein the monochromatic light emitting element is a white LED element.   The image display device according to claim 1, wherein the single color light emitting element is a yellow or green LED element.

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