Embodiments described herein relate generally to an image display apparatus.
An image display apparatus has a liquid crystal display (LCD) panel and a backlight unit. The backlight unit illuminates an image displayed on the LED panel.
The backlight unit comprises an arbitrary number of light emitting diode (LED) elements, which may be controlled based on features such as a size and a shape (for example, an aspect ratio) of a display area of the LCD panel. The backlight unit further comprises a diffuser panel or an optical sheet which diffuses light output by the LED elements and a reflective sheet which reflects a part of the light output by the LED elements, together with a circuit board which supports the LED elements.
A predetermined number of LED elements are generally arranged in a first direction and a second direction orthogonal to the first direction, respectively.
However, since light obtained by diffusing the direct light from the LED elements with the diffuser panel or the optical sheet partially coincides with reflected light from the reflective sheet differing from the direct light, uniform luminance can barely be obtained in the whole of the display area of the LED panel. That is, a problem that uneven brightness (irregularity of luminance) occurs on the image displayed on the LED panel still is not solved completely.
A general architecture that implements the various features of the embodiments will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate the embodiments and not to limit the scope of the invention.
Various embodiments will be described hereinafter with reference to the accompanying drawings.
In general, according to one embodiment, an image display apparatus comprising, a display which displays information, a light source includes a plurality of LED elements and covers each covers each of the respective LED elements, a reflective member including a plurality of openings through which the light source is exposed and which reflects illumination light from the LED elements, and a light control member, formed around each of the openings and being provided with a predetermined width in a radial direction of the openings, to control the reflection of the illumination light from each of the LED elements being reflected from the reflective member. The width of the light control member is less than half a center-to-center distance between the openings.
Embodiments will now be described hereinafter in detail with reference to the accompanying drawings.
The television device 1 comprises a liquid crystal display (LCD) panel (hereinafter referred to as a display panel) 11 to display an image, and a backlight unit 21 to illuminate the image displayed on the display panel 11.
The backlight unit 21 comprises a plurality of LED bars (light source members) 22 each including an arbitrary number of light emitting diode (LED) elements, a back bezel 4 supporting the LED bars 22 and integrated with a reflective sheet 23, a diffuser panel 24, and an optical sheet 25. Each of the LED bars 22 includes a predetermined number of LED elements positioned at predetermined intervals on a base material extending in the first direction. A predetermined number of LED bars 22 are arranged parallel to the first direction. Each of the LED elements, which are shown in an expanded view of
A front bezel 2 is positioned at a predetermined position on a front surface (i.e., the opposite side of the backlight unit 21 in the front-back direction based on the position of the display panel 11) of the display panel 11. The front bezel 2 defines the position of a display surface of the display panel 11 (an image output surface of the display panel 11) in a surface orthogonal to the front-back direction of the TV apparatus 1 in which all the components are assembled.
A middle frame 3 is positioned at a predetermined position between the display panel 11 and the backlight unit 21 in the front-back direction. The middle frame 3 defines positions of the display panel 11 and the backlight unit 21 (i.e., sets a position of the display panel 11 with respect to the backlight unit 21).
The back bezel 4 supports the middle frame 3 (i.e., the display panel 11 supported by the middle frame 3).
A back cover 5 is positioned on the back surface of the back bezel 4. The back bezel 4, i.e., the display panel 11 and the backlight unit 21 are supported between the back cover 5 and the front bezel 2. An arbitrary number of circuit boards 6 such as a control circuit, an image processing circuit, a power source drive circuit, a power supply circuit, etc., are positioned between the back cover 5 and the back bezel 4. Each of the circuit boards 6 is positioned at a predetermined position of the back bezel 4 in the embodiment. The control circuit controls operations of the TV apparatus 1. The image processing circuit processes image signals displayed on the display panel 11. The light source drive circuit controls illumination of the display panel 11 by the backlight unit 21. The power supply circuit supplies power to each element of the TV apparatus 1. A stand used when the TV apparatus 1 is placed on, for example, a desk, may be attached to the back cover 5.
As shown in
Antireflection members 23b, . . . , 23b, which will be described in detail with reference to
The light output by each LED element of the LED bars 22 is reflected from a surface (optical incidence surface) of an optical member such as the diffuser panel 24 or the optical sheet 25, and is returned to the side of the LED bars 22. The light (the return light) which is returned to the side of the LED bars 22 is approximately 30 to 40% of the light output by the LED elements. The return light is reflected from a reflection surface (a printed circuit board [PCB] surface serving as a structure of the LED bar or a resist pattern [print area] positioned on the PCB surface, and a reflective sheet) and is returned to the diffuser surface, etc. The return light, which will be described in a subsequent stage with reference to
An element similar to the antireflection members 23b, . . . , 23b may be positioned at a resist print area, etc., on a substrate (a part of the structure of the LED bars) between the LED bars 22 and a lens of each LED element of the LED bar 22.
The antireflection members 23b, . . . , 23b and the second antireflection members 23c, . . . , 23c can be realized by various methods such as coating using a black paint, a stamp of black ink or pigment, or black silk-screen printing. When the antireflection members 23b, . . . , 23b and the second antireflection members 23c, . . . , 23c are realized by a paint, the paint should be preferably a matte paint. The antireflection members 23b, . . . , 23b and the second antireflection members 23c, . . . , 23c may be, for example, stickers applied with black or matte-black color material. At least a part of the area of the antireflection members 23b, . . . , 23b and the second antireflection members 23c, . . . , 23c may be different from the other parts in density. That is, the intensity (degree of reflection) of the reflected light can be controlled by varying the density (print density/color material density) of the antireflection members 23b, . . . , 23b.
The antireflection members 23b, . . . , 23b and the second antireflection members 23c, . . . , 23c may, for example, absorb light of a predetermined wavelength. In this case, the color of the antireflection members 23b, . . . , 23b/23c, . . . , 23c may be different from black.
The antireflection members 23b, . . . , 23b will be hereinafter described with reference to
A part of light L1′ which has passed through the lens 22b of the LED element and reached the diffuser panel 24 or the optical sheet 25 is reflected from the diffuser panel 24 or the optical sheet 25 and directed to an arbitrary point (point of reflection) R2 on the reflective sheet 23. Light L2 directed to the arbitrary point (point of reflection) R2 on the reflective sheet 23 is reflected from point of reflection R2 and becomes light L2′. The intensity of light L2′ reflected from point of reflection R2 is lower than the light intensity of light L2 directed to point of reflection R2. The spectral distribution of light L2′ reflected from point of reflection R2 may be different from the spectral distribution of light L2 directed to point of reflection R2 owing to absorption into the antireflection members 23b, . . . , 23b provided at point of reflection R2. When the antireflection members 23b, . . . , 23b are not provided, light L2′ which has been reflected from the reflective sheet 23 and passed through the lens 22b of the LED element may coincide with other light and pass through the diffuser panel 24 or the optical sheet 25. Therefore, the luminance of the illumination light which reaches the side of the display panel 21 becomes greater than the expected (essentially required) luminance A as represented by “A2” in (a) of
A part of light L2′ which has passed the lens 22b of the LED element and reached the diffuser panel 24 or the optical sheet 25 is hereinafter reflected from the diffuser panel 24 or the optical sheet 25 again and directed to an arbitrary point (point of reflection) R3. The light intensity of the light reflected from point of reflection R3 is less than that of the light reflected from R2 or R1, but irregularity in luminance is improved by application of the embodiment.
As exemplified in
As exemplified in
The degree of reflection (intensity of reflection light) of each of points of reflection R1, R2, R3, . . . , can be controlled by varying the density (print density/color material density) of the point.
The vicinity of the outer periphery of the width e of each of the antireflection members 23b, . . . , 23b should preferably have a concentration gradient (gradation). The gradation can prevent rapid variation of the degree of reflection (luminance difference) between reflection from the reflective members 23b, . . . , 23b and reflection from the body of the reflective sheet 23. The diameter of the outermost periphery of the gradation is excluded from the definition of the width e described above (i.e., the above-described relationship between the width e and the distance d from the reflective sheet 23 to the diffuser panel 24 or the optical sheet 25 is not applied to the outermost periphery of the gradation).
As shown in
In the example of
The second antireflection members 23c, . . . , 23c can be arbitrarily shaped into, for example, an ellipse, an oval, a rectangle (oblong), a trapezoid or a polygon, if the variation (dispersion) of the luminance distribution seen from the side of the display panel can be confined within a predetermined range.
As shown in
Therefore, when the center-to-center distance between the openings 23a, . . . , 23a (interval between the LED elements) is the second interval LP2, the reflection light L2 reflected from the diffuser panel 24 or the optical sheet 25 is reflected from the reflective sheet 23 and directed to the diffuser panel 24 or the optical sheet 25 without passing through the lens 22b of the LED element as shown in
The antireflection members of the present embodiment control reflection of unnecessary reflection light which may become a factor for dispersion of luminance distribution and variation of color when seen from the side of the display panel. As described above, the degree of dispersion of luminance and color shading of an extensive range and various types of LED lighting can be set to fall within a predetermined range by providing the antireflection members on the reflective sheet. In addition, bright sections (hot spots) made by reflection of light from LED lighting can be reduced by providing the antireflection members at predetermined areas of a rising portion of the side surface of the reflective sheet.
Since light diffusion characteristics of the reflective sheet can be set more variously than the resist print area provided on the base material of the LED bars, a boundary between an area with black print (antireflection member) and an area without black print can be obfuscated (i.e., unnaturalness of the boundary can be reduced). The uniformity of the luminance distribution can be thereby increased.
Since the reflection of unnecessary reflection light which becomes a factor for dispersion of luminance distribution and variation of color is controlled by the antireflection members provided on the reflective sheet, the period of design and the cost of development can be reduced more than the case of changing characteristics of the lens of the LED element.
The reflection of unnecessary reflection light which becomes a factor for dispersion of luminance distribution and variation of color can be controlled by the antireflection members, and the number of the LED elements can be thereby reduced. The same LED bars can be applied (used) to various types of image display apparatuses by changing a pattern of the antireflection members. The cost of the backlight unit (the LED bars and the reflective sheet) can be thereby cut.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
The embodiments can be also realized in the following structures.
In the case where a broadcast receiver having a network function is provided with a game function by a cloud gaming, the broadcast receiver is provided with a function for automatically changing display and audio output so as to prioritize performance without having the user set the function at the time of execution of the game. Thus, users receive the benefit of convenience.
Device information of a client is reported to a server application. This allows provision of a settlement function which is suitable for the device and/or environment. The server application provides a structure which can be applied in common with a terminal.
In the case where the device is a broadcast receiver, the broadcast receiver is only provided with verification by a settlement account by email, or transmission of homepage address for the Internet settlement to another information processor by email. In the case of an information processor, the information processor is provided with both the function of credit information input settlement and the function of settlement account.
In the case where a keyboard is connected to a broadcast receiver, the broadcast receiver is provided with both the function of credit information input settlement and the function of settlement account.
In the case where a broadcast receiver can be remotely handled from a terminal device such as a tablet, the broadcast receiver is provided with both the function of credit information input settlement and the function of settlement account.
In the case where a contactless terminal device is connected to a broadcast receiver, the broadcast receiver further has a contactless settlement function.
This application claims the benefit of U.S. Provisional Application No. 62/020,157, filed Jul. 2, 2014, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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62020157 | Jul 2014 | US |