Level shift circuit, display apparatus, and portable terminal

Abstract

In the structure in which an input signal IN and a reverse-phase signal XIN thereof are externally input, an external IC is required for generating the reverse-phase signal XIN, and the number of required input signal terminals is two. A level shift circuit formed on an insulating substrate, such as a glass substrate, using transistors with large characteristic variations, for example, TFTs with high thresholds Vth, includes a complementary generator unit ( 11 ) driven by a first power supply (VCC) having an amplitude voltage equal to the amplitude voltage of a signal externally input from the substrate to generate complementary signals from a single-phase input signal IN. The complementary signals generated by the complementary generator unit ( 11 ) are level-shifted by a level shift unit ( 14 ). Therefore, it is no longer necessary to externally input the reverse-phase signal XIN.

1 - 2 . (canceled)  
   
   
       3 . A level shift circuit formed on an insulating substrate, comprising: 
 a complementary generator unit driven by a first power supply having an amplitude voltage equal to an amplitude voltage of a signal input from the outside of the substrate for generating a complementary signal from the single-phase input signal; and    a level shift unit driven by a second power supply having a higher voltage than the first power supply for shifting the level of the complementary signal, and    wherein the level shift unit has a sampling-latch circuit structure in which the complementary signal is sampled in synchronization with a sampling pulse and is latched,    
   
   
       4 - 5 . (canceled)  
   
   
       6 . A display apparatus comprising: 
 a display unit having a matrix of pixels formed on a transparent insulating substrate; and    a level shift circuit formed on the transparent insulating substrate together with the display unit for shifting the level of an input signal from the outside of the substrate so as to drive the display unit,    wherein the level shift circuit includes:    a complementary generator unit driven by a first power supply having an amplitude voltage equal to an amplitude voltage of a signal input from the outside of the substrate for generating a complementary signal from a single-phase input signal; and    a level shift unit driven by a second power supply having a higher voltage than the first power supply for shifting the level of the complementary signal, and    wherein the level shift unit has a sampling-latch circuit structure in which the complementary signal is sampled in synchronization with a sampling pulse and is latched.    
   
   
       7 . A display apparatus according to  claim 6 , wherein the level shift unit uses a combination of a source-input-type level shift circuit and sampling-latch-type level shift circuits for input signals including a master clock, a horizontal synchronous pulse, a vertical synchronous pulse, and display data, and 
 the master clock is level-shifted by the source-input-type level shift circuit, and the horizontal synchronous pulse, the vertical synchronous pulse, and the display data are level-shifted by the sampling-latch-type level shift circuits.    
   
   
       8 . A display apparatus according to  claim 6 , wherein the level shift circuit is formed on the transparent insulating substrate using low-temperature polysilicon or continuous grain silicon.  
   
   
       9 . (canceled)