Patent Application
20090051637
1. Field of the Invention
The invention relates to a display device, and more particularly to a display device with dynamic backlight source.
2. Description of the Related Art
A liquid crystal panel is comprised of two glass substrates and a liquid crystal layer inserted therebetween. The liquid crystal panel is, for example, utilized in the LCD, the LCD TV, and the display devices of the portable electronic equipments, such as lap-top computer, mobile phones, PDA and etc.
The transmissive liquid crystal panel uses a backlight as a light source. Since the backlight is typically a white light source, for a color LCD, each pixel is generally comprised of three sub-pixels corresponding with a red filter, a green filter, and a blue filter, respectively. The desired color displayed by each pixel is obtained by controlling the amount of light passing through each sub-pixel according to each color filter.
As shown in
Display devices are provided. An exemplary embodiment of such a display device comprises a processor for receiving an image signal and generating a data signal and a luminance signal accordingly, a display panel comprising display cells, a data driver generating driving signals according to the data signal for driving the display cells, and a backlight module comprising light emitting elements, each light emitting element being arranged to correspond to each display cell respectively for emitting light to each display cell according to the luminance signal.
Another exemplary embodiment of A display device comprises a processor for receiving an image signal and generating a data signal and a luminance signal accordingly, a display panel comprising display cells, wherein each pixel unit comprises a red display cell, a green display cell and a blue display cell, a data driver generating driving signals according to the data signal for driving the display cells, and a backlight module comprising light emitting elements, each light emitting element being arranged to correspond to each display cell respectively for emitting light to each display cell according to the luminance signal.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
In LCD panel 100, a plurality of display cells 200 are arranged to form a matrix. Display cells 200 are connected to a plurality of data lines D11, D12, . . . , D1M and a plurality of gate lines G11, G12, . . . , G1N. The equivalent circuit of each display cell 200 includes a switch 201, which may be a TFT, and a capacitor 202 connected between the switch 201 and a supplied voltage V1. The gate driver 51 outputs scan signals to each gate lines G11, G12, . . . , G1N according to a predetermined sequence. When one gate line is asserted by a scan signal, the switches 201 within display cells on the same row are turned on. Then, the data driver 61 outputs the driving signals (gray values) to the corresponding display cells 200.
In OLED panel 220, the light emitting elements 300 are arranged to form a matrix. Light emitting elements 300 are connected to data lines D21 D22, . . . , D2M and gate lines G21, G22, . . . , G2N. Each emitting element 300 includes a data switch 301, which may be a TFT, a capacitor 302, a driving switch 303 and an OLED 304. The driving switch 303 is a TFT that generates a driving current for driving the OLED 304 for producing light. The gate driver 52 outputs one or more scan signals to each gate lines G21, G22, . . . , G2N according to a predetermined sequence. When one gate line is asserted by a scan signal, the corresponding data switches 301 within the light emitting elements 300 on the same row are turned on. Then the data driver 62 controls the corresponding light emitting elements 300 through data lines D21, D22, . . . , D2M to emit light according to luminance signal SLM. There are also other types of pixel circuits for driving the OLEDs 304 known by the person skilled in the art.
According to one embodiment of the invention, each display cell 200 shown in
According to one embodiment of the invention, the processor 80 generates the data signal SDATA by adjusting an attribute of the image signal SIM, such as the contrast ratio, brightness thereof, and generates the luminance signal SLM based on the adjusted image attribute. According to another embodiment of the invention, since the image signal SIM for a color LCD comprises brightness of a red channel signal, a green channel signal and a blue channel signal of each pixel unit, processor 80 generates luminance signal SLM to the data drive 62 according to those individual brightness information of each pixel. In the embodiment of the invention, since each light emitting element 300 is arranged corresponding to each display cell 200, each light emitting element 300 can act as an individual backlight source for each display cell 200. For example, when there is a black pixel adjacent to a white pixel for an image data is to be displayed, the corresponding light emitting elements of the black pixel do not illuminate while the corresponding light emitting elements of the white pixel do generate a white light. In this way, the display device 30 can not only dynamically and precisely control the brightness of each individual display cell, but also achieve better contrast and reduce power consumption.
While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. Those who are skilled in this technology can still make various alterations and modifications without departing from the scope and spirit of this invention. Therefore, the scope of the present invention shall be defined and protected by the following claims and their equivalents.
