Patent Grant
10891908
The present invention relates to a display system and a driver circuit, and more particularly, to a liquid crystal display system and a related driver circuit.
A liquid crystal display (LCD), which is a flat panel display having the advantages of low radiation, light weight and low power consumption, is widely used in various information technology (IT) products such as notebook computers, personal digital assistants (PDA), and mobile phones. The principle of LCD is to vary the arrangement of liquid crystal molecules in a liquid crystal layer by varying the voltage difference between two terminals of the liquid crystal layer. The transparency of the liquid crystal layer may change accordingly, which is further incorporated with the light source provided by a backlight module to display images.
The LCD usually includes a driver chip. After image data is transmitted from a host to the driver chip, the image data may be processed by the driver chip and sent to the panel from the driver chip. People in the industry are making their best efforts to improve the image quality such as resolution and contrast. As for the driver chip, various image processing techniques are applied to achieve this purpose. In addition, privacy protection for electronic products and screen becomes an important issue to be dealt with.
It is therefore an objective to provide a display system and a driver circuit capable of enhancing image contrast and providing privacy protection function.
An embodiment of the present invention discloses a display system, which comprises a display device and a driver circuit. The display device has a first panel and a second panel, wherein the first panel and the second panel are disposed with a gap therebetween. The driver circuit is coupled to the display device and comprises a protection circuit. The protection circuit, coupled to the second panel of the display device, is configured to generate a gray scale data to be outputted to a pixel among a plurality of pixels of the second panel according to a luminance corresponding to the pixel and according to whether a protection function is enabled.
Another embodiment of the present invention discloses a driver circuit of a display system. The display system comprises a display device having a first panel and a second panel. The driver circuit comprises a protection circuit. The protection circuit, coupled to the second panel of the display device, is configured to generate a gray scale data to be outputted to a pixel among a plurality of pixels of the second panel according to a luminance corresponding to the pixel and according to whether a protection function is enabled. Wherein, the first panel and the second panel are disposed with a gap therebetween.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
Please refer to
In order to enhance the contrast of the display image, an LCD device with a dual panel structure is provided. Please refer to
In an embodiment, each pixel of the display panel 202 includes three subpixels having three primary colors, i.e., red (R), blue (B) and green (G), respectively, and each pixel of the display panel 202 is superposed on one pixel (e.g., P1, P2, etc.) of the backlight panel 204, as shown in
Please refer to
In order to increase the contrast of the display image, the gray scale data to be outputted to the backlight panel 204 may be determined according to the image data transmitted to corresponding subpixels which are superposed on the target pixel of the gray scale data on the backlight panel 204, to control the penetration degree of backlight through the backlight panel 204. For example, the gray scale data outputted to a pixel of the backlight panel 204 may have a higher magnitude if the image data for the corresponding subpixels of the display panel 202 has higher luminance; and the gray scale data outputted to a pixel of the backlight panel 204 may have a lower magnitude if the image data for the corresponding subpixels of the display panel 202 has lower luminance. In this manner, the contrast of the display image may be increased, since the higher gray scale data for the pixels having higher luminance may generate higher penetration degree of backlight through the backlight panel 204. Each pixel may receive a respective gray scale data for controlling its penetration degree of backlight, and thus the backlight intensity in each pixel may be controlled independently and flexibly; hence, the contrast may be enhanced to a satisfactory level.
In general, the driver circuit 410 may include a timing controller (which is omitted in
Please note that in the LCD device 200 or 400, there is a gap between the display panel 202 and the backlight panel 204. The gap may separate the two panels 202 and 204, and thereby influence the image seen from an oblique view.
In an embodiment, the privacy protection function may be flexibly controlled by the privacy protection circuit in the driver circuit. Please return to refer to
On the other hand, when the privacy protection function is enabled, the privacy protection circuit 416 may convert the luminance of image data to the gray scale data following the curve Y2, which leads to gray scale data different from those obtained based on the curve Y1 under the same luminance. In detail, the conversion of the curve Y2 may be considered as a linear conversion, where the higher luminance may be converted into higher gray scale data with an approximately linear relationship. Therefore, different luminance may lead to different backlight intensities on the backlight panel; hence, any two pixels having different image data may usually be corresponding to different gray scale data for the backlight panel. If a viewer watches the panel from an oblique view angle or side view angle, the viewer may see a blurred image since each pixel may reflect a wrong backlight intensity at the oblique view angle or side view angle. If the image includes texts and/or characters, the texts and/or characters may become blurred at the oblique view angle, which achieves the privacy or confidential protection of the LCD device.
Please note that the present invention aims at providing a display device with a dual panel structure controlled by a driver circuit having a privacy protection circuit, where the two panels of the display device have a gap therebetween, and the privacy protection circuit may enable the privacy protection function to prevent a peek from an oblique view angle. Those skilled in the art may make modifications and alternations accordingly. For example, in the dual panel structure, the gap between the two panels may be implemented in any manner. In an embodiment, the gap may be an air gap or vacuum between the two panels, where the two panels are combined and connected through the non-display area. Preferably, the width of the gap may be greater than a value that allows the displayed text to become blurred from an oblique view angle when the privacy protection function is enabled. The width of the gap may also be adjustable by the producer of the display device. A wider gap may lead to more evident ghost images, which achieve better peek prevention effects. Further, in the above embodiments, each pixel has three subpixels with three primary colors, but those skilled in the art should understand that the structures of pixels and subpixels are not limited thereto. Also, in the above embodiments, the LCD device is applied to achieve the high contrast and privacy protection effects; in another embodiment, the dual panel structure and related implementation may be applied to other type of display device having the backlight source.
In addition, the privacy protection circuit may be implemented in any manner. In detail, the conversion of gray scale data is based on the curve shown in
To sum up, the present invention provides a display system and a driver circuit which are capable of enhancing image contrast and realizing privacy protection. In an embodiment, the display device has a dual panel structure with a display panel and a backlight panel, and a gap may be disposed between the two panels of the display device. With the disposition of the gap, the images from an oblique view angle may become blurred, which achieves the privacy protection effects. The driver circuit of the present invention is configured to output image data to the display panel and output gray scale data corresponding to luminance of the image data to the backlight panel. The driver circuit may include a privacy protection circuit, which is configured to generate the gray scale data to be transmitted to the backlight panel according to the luminance information and also according to whether the privacy protection function is enabled or not. In general, the gray scale data may enhance the image contrast by controlling the backlight intensity in each pixel. When the privacy protection function is enabled, the privacy protection circuit may perform linear conversion between the luminance and the outputted gray scale data, to prevent a peek from an oblique view angle and thereby achieve privacy protection with the gap disposed between the panels.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 20080246780 | Cho | Oct 2008 | A1 |
