JPH03282516A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To eliminate the difference in various display densities between upper and lower screens by providing two pieces of independent power source sections and a correcting section which receives the liquid crystal driving voltage controlled in the outside and supplies different voltages to two pieces of the power source sections in driver groups for upper and lower screen displays. CONSTITUTION:The upper screen display section 50 is driven by the driver group 40 for the upper screen display which receives the driving voltage generated by the power source section 30 for the upper screen. The lower screen display section 51 is driven by the driver group 41 for the lower screen display which receives the driving voltage generated by the power source section 31 for the lower screen. The various display densities over the entire part of the screen are regulated by increasing and decreasing the voltage tube impressed to a driving voltage input 10 by a variable resistor provided in the outside. The different voltages are supplied from this input voltage to the power source sections 30, 31 by the correcting section 20 in such a manner that the display densities of the display sections 50, 51 are uniformized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal display device mainly used as a display section of a small electronic device, and particularly relates to the supply of liquid crystal drive voltage in a liquid crystal display device with a two-screen configuration, upper and lower. .

[Prior Art] Conventionally, this type of liquid crystal display device has one power supply section,
The same driving voltage was supplied to the upper side display driver group and the lower screen display driver group [Problem to be solved by the invention] Because the same driving voltage was supplied to the two driver groups that drive the upper and lower screens, there were differences in the wiring length from the power supply section to the driver groups, variations in the characteristics of the driver groups, and a matrix pattern on the display section. There is a drawback that a difference in display density between the one screen and the bottom screen is likely to occur due to a difference in resistance between the electrodes wired to the top and bottom screens. Furthermore, the difference in display density between the upper and lower screens becomes more noticeable when halftones are displayed by frame thinning or the like.

[Means for Solving the Problems] In order to eliminate this drawback, the liquid crystal display device of the present invention has the following features:
It has first and second power supply units corresponding to the upper side display driver group and the lower screen display driver group, respectively, and a correction unit for supplying desired voltages to the first and second power supply units, respectively. ing.

[Embodiment] FIG. 1 is a functional block diagram of an embodiment of the present invention. 1
0 is a drive voltage input, 20 is a correction unit, 30 is a power supply unit for the upper screen, 31 is a power supply unit for the lower screen, 40 is ]: screen display driver group, 41 is a lower side display driver group, 50 is the upper screen The display section 51 is a child screen display section. Here, the upper screen display section 50 is driven by the main screen display driver group 40 that receives a drive voltage generated by the upper screen power supply section 30.

Further, the sub-screen display unit 51 similarly receives the drive voltage generated by the lower-screen power supply unit 31, and the lower-side display driver group 4
1. The display shading of the entire screen is generally done by increasing or decreasing the voltage applied to the drive voltage input 10 by a variable resistor called a contrast volume installed externally, and the correction unit 2o is adjusted based on this input voltage.
As a result, the upper screen power supply section 30 and the lower screen power supply section 31,
Different voltages are supplied so that the display densities of the upper screen display section 50 and the sub-screen display section 51 are uniform.

[Effects of the Invention] As explained above, the present invention provides two independent power supply units for each of the main screen display driver group and the lower side display driver group, and an externally controlled liquid crystal drive voltage. By including a correction section for supplying different voltages to the two power supply sections, the conventional function of controlling the display density of the entire screen using an external contrast volume is retained, and the above-mentioned features are improved. - It has the effect of eliminating the difference in display shading between the lower surfaces.

The difference in display shading between the upper and lower screens depends not only on the aforementioned variations in wiring length and characteristics of the driver group, but also on the displayed pattern, but by making the correction section adjustable externally, This also has the effect of allowing the user to adjust the display to the optimum display depending on the software being used.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of an embodiment of the present invention. 10... Drive voltage input, 2o... Correction section. 30... - power supply unit for upper screen, 31... power supply unit for both lower sides, 40... driver group for main screen display, 4[-driver group for lower side display. 50... Upper screen display section, - Sub-screen display section.

Claims (1)

[Claims] In a liquid crystal display device having an upper and lower screen configuration, a first power supply section for supplying a driving voltage to a group of drivers for displaying an upper screen, and a second power supply section for supplying a driving voltage to a group of drivers for displaying a lower screen. and a correction section that receives an externally controlled liquid crystal drive voltage and supplies desired voltages to the first and second power supply sections, respectively.