TWI465776B - Display device - Google Patents

Description

monitor

The present invention relates to a display, and more particularly to a display having a brightness enhancing sheet.

With the advancement of technology, various types of displays have been widely used, such as liquid crystal displays for mobile phones and LCD TV screens ("SOS liquid crystal TV display", Electron Devices Meeting, 1974 International, pp. 5-5, Volume 20, 1974). The light-emitting diode display is applied to a large display board.

Most of the displays include a substrate for presenting an image to the outside. The material of the substrate is generally a transparent glass or plastic material, and light inside the display is emitted from the transparent substrate, thereby achieving the purpose of display. However, the refractive index of the substrate material is greater than the refractive index of the air, so that some of the light is lost in the substrate due to total reflection, which affects the brightness of the display.

In view of this, it is necessary to provide a display having a high luminance.

A display includes a display screen and a brightness enhancement sheet. The brightness enhancing sheet comprises a transparent substrate having opposite surfaces, wherein one surface is provided with a plurality of positive quadrangular pyramid shaped microlenses, and the other surface is attached to the surface of the display screen, and the side surface of the plurality of microlenses is The angle between the bottom faces is θ, and the angle θ ranges from 30 degrees ≦ θ < 90 degrees.

The display using the brightness-increasing sheet has a plurality of positive-pyramid-shaped microlenses of the brightness-increasing sheet to destroy the total reflection condition of the display-exposed light to the outside, so that more light is emitted to the outside, thereby increasing the brightness of the display.

10‧‧‧Bright sequins

12‧‧‧Base

14‧‧‧Microlens

20‧‧‧ display

22‧‧‧LCD screen

222‧‧‧Lighting surface

24‧‧‧Lighting area

242‧‧‧ facing the area

244‧‧‧ both sides

26‧‧‧ square image

1 is a perspective view of a brightness enhancement sheet according to a first embodiment of the present invention.

2 is a perspective view showing a display using the brightness enhancement sheet of the first embodiment of the second embodiment of the present invention.

Fig. 3 is a light path diagram showing a blurred image produced by the display of the second embodiment.

Figure 4 is an optical simulation of the image displayed on the LCD screen when the brightness enhancement is not attached.

FIG. 5 to FIG. 7 are optical simulation diagrams showing the blur range of the liquid crystal display screen when the liquid crystal display screen is attached with the brightness enhancement sheet, and the side surface and the bottom surface of the microlens are at different angles.

The invention will now be described in further detail with reference to the accompanying drawings.

Referring to FIG. 1, a first embodiment of the present invention provides a brightness enhancing sheet 10 for attaching to a surface of a display screen to increase the luminance of the display screen. The brightness enhancing sheet 10 includes a substrate 12 and a plurality of regular quadrangular pyramid shaped microlenses 14 disposed on the surface of the substrate 12. The plurality of microlenses 14 are identical in shape and size, arranged in a matrix on the surface of the substrate 12, adjacent to the microlenses 14 There are spacings and the spacing is equal. It can be understood that adjacent microlenses 14 can also be closely arranged.

The material of the substrate 12 and the plurality of microlenses 14 is generally a plastic material such as polymethyl methacrylate (PMMA). Preferably, the plurality of microlenses 14 are integrally formed with the substrate 12 and have the same material, and the materials of the substrate 12 and the microlenses 14 have the same or substantially the same refractive index as the material of the display screen.

After the brightness enhancing sheet 10 is attached to the surface of the display screen, the light emitted from the surface of the display screen enters the brightness enhancing sheet 10. Since the positive quadrangular pyramid shaped microlens 14 has four sides inclined with respect to the surface of the display screen, Compared with the incident angle of the display directly incident into the air, the incident angle of the light from the microlens 14 incident to the air changes, destroying the total reflection condition, allowing more light to be emitted to the outside, thereby increasing the display screen. Brightness.

As shown in FIG. 2, a second embodiment of the present invention provides a display 20 including a liquid crystal display 22 and a brightness enhancing sheet 10 attached to the surface of the liquid crystal display 22. The liquid crystal display panel 22 has a light-emitting surface 222 for emitting light to the outside to achieve image display. The substrate 12 of the brightness-increasing film 10 is closely attached to the light-emitting surface 222 of the liquid crystal display panel 22. It can be understood that the liquid crystal display 22 can also be replaced with other types of display screens, such as a cathode ray tube display, a light emitting diode display, and the like.

The liquid crystal display 22 can display information such as images. After the light emitted by the liquid crystal display panel 22 passes through the brightness enhancing sheet 10, the microlens 14 having a square pyramid shape has four sides inclined with respect to the light emitting surface 222 of the liquid crystal display panel 22, Therefore, compared with the incident angle of light directly incident on the liquid crystal display 22 into the air, the incident angle of the light when the microlens 14 is incident on the air changes, destroying the total reflection condition, and causing more light to be emitted to the outside. Thereby increasing the brightness of the display. The larger the angle between the respective sides of the microlens 14 and the bottom surface, the higher the luminance of the liquid crystal display panel 22.

When the brightness enhancement sheet 10 is attached to the light-emitting surface 222 of the liquid crystal display panel 22, a certain degree of image blurring is caused, but by controlling the angle between each side surface of the microlens 14 and the bottom surface, the image blur range can be adjusted. Controlled within acceptable limits. Please refer to FIG. 3 to FIG. 8 together. The reason for the image blur generation and the method for controlling the brightness enhancement film 10 to change the blur range are specifically described below: Referring to FIG. 3, the reason why the brightness enhancement film 10 causes image blurring is as follows: Here, in order to more clearly indicate the cause of image blurring, one of the light-emitting regions 24 smaller than the surface area of the liquid crystal display panel 22 emits light to the brightness-increasing sheet 10 as example. A portion of the light emitted by the illuminating region 24 is emitted to the facing region 242 of the brightness enhancing sheet 10 facing the illuminating region 24, and a portion of the illuminating sheet 10 is emitted to the side regions 244 of the highlighting sheet 10 adjacent to the facing region 242, due to the microlens of the brightness enhancing sheet 10. 14 changes the incident angle of the light, destroys the total reflection condition, and causes the light to exit to the outside (if there is no brightener 10, the light incident on the side regions 244 is reflected back to the liquid crystal display 22 due to total reflection), This produces image blur.

As shown in FIG. 4, an optical simulation of the image displayed by the brightness enhancing film 10 is not attached to the liquid crystal display panel 22. As shown in FIG. 5 to FIG. 7, an optical simulation image of the image is displayed after the brightness enhancement film 10 is attached to the liquid crystal display panel 22. In this embodiment, the square image 26 is displayed when the liquid crystal display panel 22 is not attached with the brightness enhancing sheet 10. Since the microlens 14 of the brightness enhancing sheet 10 has a regular quadrangular pyramid shape, it has two opposite sides, and each side The angle between the bottom surface of the microlens 14 and the bottom surface of the microlens 14 is equal, so that the image blurring range displayed by the liquid crystal display panel 22 to which the brightness enhancing film 10 is attached is the area adjacent to each side of the square image 26, and the square image 26 The diagonal areas adjacent to each corner do not cause image blurring.

The angle between the side surface of the microlens 14 and the bottom surface is defined as θ. The image shown in the optical simulation diagrams of FIGS. 5 to 7 is 50 μm on the side of the bottom surface of the microlens 14 and 7.7 μm apart from the adjacent microlens 14 . When the θ is 30 degrees, 45 degrees, and 60 degrees, the analogy is formed. The side length of the square image 26 is L=177 μm, and the side length of the square image 26 is about the distance between the bottom side of the microlens 14 and the adjacent microlens 14. The sum is three times, so the display image attached to the brightness enhancement sheet 10 in Fig. 4 will have a mesh-like shape.

Defining the intensity of the square image 26 is the maximum luminous intensity, defining the luminous intensity The light-emitting display range of 1/e2 or more equal to or greater than the maximum light-emission intensity is the actual light-emitting range, and the actual light-emitting range is L' in the vertical direction from the side of the square image 26, and the value of the image blur range is expressed as D = (L' - L) / 2, that is, D is the distance from the fringe of the 1/e 2 of the maximum luminous intensity to the side of the square image 26 adjacent to the stripe.

The optical analogy is set at an angle θ of 30 degrees, 45 degrees, and 60 degrees between the side surface of the microlens 14 and the bottom surface, respectively. The result is as follows: as shown in FIG. 5, when the angle θ is 30 degrees, the liquid crystal display 22 is displayed. For example, the optical simulation map has a value D1 of about 107.5 μm.

As shown in FIG. 6, the optical simulation image of the image displayed on the liquid crystal display panel 22 when the angle θ is 45 degrees, at this time, the value D2 of the image blurring range is about 167.5 μm.

As shown in FIG. 7, the optical simulation image of the image displayed on the liquid crystal display panel 22 when the angle θ is 60 degrees, at this time, the value D3 of the image blurring range is about 282.5 μm.

As can be seen from the above, as the angle between the side surface and the bottom surface of the microlens 14 increases, the display brightness of the display increases, but the value of the image blur range displayed by the display also increases, that is, the degree of blurring of the image becomes high. For different types of displays, the range of image blur that is acceptable to the human eye is different. Therefore, the angle of the image blur can be adjusted to an acceptable range of the human eye by adjusting the angle between the side surface and the bottom surface of the microlens 14 according to actual needs. Improved display brightness and display quality. In this embodiment, when the size of the display element ranges from 177 μm × 177 μm to 5000 μm × 5000 μm, and the distance between adjacent primitive elements is 35 μm to 177 μm, the range of the angle θ between the side surface and the bottom surface of the positive quadrangular pyramid shaped microlens 14 Preferably, 30 degrees ≦ θ < 90 degrees, so that the display brightness is improved, and the image blur range is controlled to be acceptable to the human eye.

Compared with the prior art, the display 20 of the present embodiment attaches a brightness enhancing sheet 10 to the light emitting surface 222 of the liquid crystal display panel 22, and the brightness enhancing sheet 10 includes a plurality of micro-lenses 14 of a regular quadrangular pyramid shape, so that the light emitted from the liquid crystal display panel 22 can be further Excessively exits to the outside world, thereby increasing the brightness of the display 20. In addition, by adjusting the angle between the side surface of the microlens 14 of the positive quadrangular pyramid shape of the embodiment and the bottom surface, the image blurring range is acceptable to the human eye, which not only improves the display brightness but also ensures the display quality, so that the brightness enhancement sheet 10 is provided. The design is much simpler.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧Bright sequins

12‧‧‧Base

14‧‧‧Microlens

20‧‧‧ display

22‧‧‧LCD screen

222‧‧‧Lighting surface

Claims (5)

A display comprising a display screen having a light exiting surface for emitting light, the improvement comprising: further comprising a brightness enhancing sheet comprising a transparent substrate, the transparent substrate having opposite surfaces, wherein a surface is provided with a plurality of positive quadrangular pyramid shaped microlenses, and the other surface is attached to the light emitting surface of the display screen. The angle between the side surface and the bottom surface of the plurality of microlenses is θ, and the angle θ ranges from 30 degrees ≦ θ<90 degrees. . The display of claim 1, wherein the plurality of microlenses are equal in shape and size and closely arranged on the surface of the transparent substrate. The display of claim 1, wherein the plurality of microlenses have the same shape and size, and the adjacent microlenses have a pitch and the respective pitches are equal. The display of claim 1, wherein the transparent substrate is integrally formed with the microlens. The display of claim 1, wherein the transparent substrate and the microlens are made of polymethyl methacrylate.