Abstract: A driver circuit to drive a display by inverting the voltage polarity operates with a reduced power consumption. The driver circuit includes a driving voltage selector circuit including positive and negative driving voltage selector circuits alternately arranged therein and a circuit which conducts a change-over operation between a state in which signals respectively from the positive and negative driving voltage selector circuits are respectively outputted to first and second terminals in a first horizontal period and a state in which signals respectively from the positive and negative driving voltage selector circuits are respectively sent to second and first terminals in a second horizontal period.

Abstract: In a driving circuit for a multiple gray scale liquid crystal device, the least significant half of a given image data is decoded by a sub decoder, and one interpolating voltage is selected from a plurality of interpolating voltages by a sub switch circuit in accordance with the decoded result, so that the selected interpolating voltage Vc is applied across a capacitor. Next, the most significant half of the given image data is decoded by a main decoder, and one main voltage is selected from a plurality of main voltages by a main switch circuit in accordance with the decoded result, so that the selected main voltage Vk is supplied to one terminal of the capacitor. With this, a voltage V.sub.CH at the other terminal of the capacitor becomes {Vc+Vk}. Accordingly, by selecting Vc and Vk, it is possible to generate a number of output driving voltages corresponding to a number of gray scale levels, with a reduced number of external voltage supplies and with a reduced cost.

Abstract: A liquid crystal display driving circuit comprises a plurality of transfer gates having their one end connected in common to a source line of a liquid crystal display panel and their other end connected to a plurality of driving voltages, respectively, for supplying a different voltage to the source line. A control circuit receives an image input data for selectively turning on the transfer gates, for the purpose of realizing a multiple gray scale display. The control circuit is configured to turn on one transfer gate selected from the plurality of transfer gates during a first period of one display period, and then, to maintain the turned-on condition of the selected transfer gate during the remaining period of one display period, or to simultaneously turn on two transfer gates which are selected from the plurality of transfer gates and which include the selected transfer gate during the remaining period of one display period.

Abstract: An improvement of the LCD driving semiconductor IC which supplies a plurality of source driving voltages (corresponding to the horizontal scanning voltage of a CRT) to a plurality of source driving lines of an active matrix type LCD of TFT base is proposed.

Abstract: A driving circuit for a liquid crystal display comprises: a selector driving circuit having a plurality of shift registers and latch circuits for outputting hold signals latched in the latch circuits; a plurality of selector circuits each for selecting one reference coltage corresponding to the hold signal; a plurality of hold capacitors each being charged by the selected reference voltage; and a plurality of source follower circuits each receiving the hold voltage from the hold capacitor and outputting a driving voltage for the liquid crystal display. The driving circuit further comprise a plurality of comparator circuits each receiving the output driving voltage and the reference voltage selected and switching the connection of a ramp voltage to the hold capacitor. Each source follower circuit provided for each stage requires a constant current source and only one output driver transistor instead of as many transistors as the number of gradations, which transistor commonly operates over all the gradations.