Patent Application
20090066675
1. Field of Invention
The invention relates to a display driver, and more particularly to a digital-to-analog converter.
2. Description of Related Arts
Referring to the
An object of the present invention is to simplify the bus lines between the timing controller and the source driver.
Another object of the present invention is to provide a programmable digital to analog converter for an LCD panel.
Accordingly, in order to accomplish the one or some or all above objects, the converter comprises a reference voltage generator for generating a plurality of reference voltages based on a plurality of reference signals respectively, the reference voltage generator comprising: a resistor string comprising a plurality of resistors in serial for providing a plurality of voltages, and a plurality of reference decoders, each receiving said voltages from said resistor string and selectively outputting a reference voltage from said voltages based on the corresponding reference signal, and a data decoder receiving the reference voltages for selectively outputting an analog voltage based on a data signal.
One or part or all of these and other features and advantages of the present invention will become readily apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of one of the modes best suited to carry out the invention. As it will be realized, the invention is capable of different embodiments, and its several details are capable of modifications in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.
Referring to
Referring to
The DAC 204 receives the gamma reference signals r to decode the data signals D, from the level shifter 203, into analog driving voltages.
Referring to
The reference decoders 305 are programmable and controlled by the gamma reference signals r, which includes gamma reference signals r1-rn sequentially sent from the timing controller 101. Each of the reference decoders 305 selects a voltage from the resistor string, based on the corresponding gamma reference signal r, as a gamma reference voltage Vr and outputs the generated reference voltage Vr to the corresponding unit gain buffers 306.
The data decoder 310 selects a voltage from gamma reference voltages Vr1-Vrn as a driving voltage Vd by decoding the data signals D.
One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting.
The foregoing description of the preferred embodiment of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or to exemplary embodiments disclosed. Accordingly, the foregoing description should be regarded as illustrative rather than restrictive. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. The embodiments are chosen and described in order to best explain the principles of the invention and its best mode practical application, thereby to enable persons skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated. It should be appreciated that variations may be made in the embodiments described by persons skilled in the art without departing from the scope of the present invention as defined by the following claims. Moreover, no element and component in the present disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the following claims.
