Gamma voltage generating circuit, source driver and display device including the same

Abstract

A display device including a display unit including a scan line, a data line, and a pixel, a gate driver supplying a scan signal, and a source driver supplying a data voltage, in which the source driver includes a gamma voltage generator generating different gamma voltages in response to a gamma enable signal, a digital-to-analog converter generating the data voltage corresponding to a gray scale value using the gamma voltages, and a source buffer outputting the data voltage, the gamma voltage generator includes a first resistor string setting a range of the gamma voltages, gamma buffers outputting selected voltages among divided voltages within the voltage range, and a second resistor string including tabs to divide a voltage between the tabs to generate the gamma voltages, and at least some of the gamma buffers are turned on in a first period and are turned off in a second period.

What is claimed is: 
     
         1 . A display device comprising:
 a display unit including a scan line, a data line, and a pixel connected to the scan line and the data line;   a gate driver configured to supply a scan signal to the scan line; and   a source driver configured to supply a data voltage to the data line,   wherein the source driver includes:
 a gamma voltage generator configured to generate gamma voltages having voltage levels different from each other in response to a gamma enable signal; 
 a digital-to-analog converter configured to generate the data voltage corresponding to a gray scale value using the gamma voltages; and 
 a source buffer configured to output the data voltage to the data line, wherein the gamma voltage generator includes: 
 a first resistor string configured to set a voltage range of the gamma voltages; 
 gamma buffers configured to output selected voltages among divided voltages within the voltage range; and 
 a second resistor string including tabs respectively connected to output terminals of the gamma buffers, the second resistor string being configured to divide a voltage between the tabs to generate the gamma voltages, 
   wherein one horizontal time includes a first period and a second period subsequent to the first period,   wherein a first group of the gamma buffers are configured to be turned on in both of the first period and the second period,   wherein a second group of the gamma buffers are configured to be turned on in the first period and turned off in the second period, and   wherein the second group of the gamma buffers are repeatedly turned on and off with a period of the one horizontal time.