62results about How to "Improved contrast characteristics" patented technology

In a display panel, a dummy pulse of a predetermined voltage signal is superimposed on a data signal and the dummy pulse has an amplitude much larger than the amplitude of the data signal, and thus a signal waveform applied to a light modulation layer such as LC layer is changed to a high frequency wave. The applying position of the dummy pulse is varied according to each color of R, G and B, or varied according to frame or field. By performing a MLS drive with the dummy pulse superimposed on the data signal, the amplitude difference between the selection signal and the data signal can be reduced. Thus, a common driver IC and a segment driver IC can be formed as one semiconductor chip to be placed on one side, constructing a three side free type.

The invention relates to the liquid crystal field, and especially relates to a liquid crystal composition and applications thereof in the liquid crystal display field. The liquid crystal composition is composed of the following compounds in parts by weight: 5 to 40 parts of one or more compounds represented by the formula I, 2 to 30 parts of one or more compounds represented by the formula II, and 20 to 70 parts of one or more compounds represented by the formula III, and may also comprises 4 to 30 parts of one or more compounds represented by the formula IV, or / and 5 to 25 parts of one or more compounds represented by the formula V to IX. By the cooperation among the compounds, the rotation viscosity of the liquid crystal composition can be effectively reduced, the related performances of mixed liquid crystal are improved, and thus the responding time is reduced. The provided liquid crystal composition can be used to produce quick response liquid crystal display with a plurality of display modes.

Disclosed is a method of driving a plasma display panel enabling to improve an overall contrast characteristic of the plasma display panel by reducing a voltage difference between scan and sustain electrodes Y and Z to decrease an emission amount of light generated by a discharge between the scan and sustain electrodes Y and Z. The present invention includes a first step of applying a reset pulse to the scan electrode to form predetermined wall charges on the electrodes for a set-up period and a second step of applying a pulse of a predetermined level to the sustain electrode to reduce a voltage difference between the scan and sustain electrodes while the reset pulse is applied.

A display characterized in that it comprises a selective reflecting layer (SR) provided between a quarter-wave plate (WP) and a light-emitting layer (64), containing liquid crystal molecules aligned at predetermined helical pitches, transmitting a first circularly polarized light, and selectively reflecting a second circularly polarized light having a polarity opposite to that of the first circularly polarized light and a predetermined wavelength, the light-emitting layer (64) has at least one peak wavelength, the selective reflecting layer (SR) has m selective reflection wavelength regions when the number of peak wavelengths of the light-emitting layer (64) is m, the peak wavelength lambdap(k) of the light emitted from the light-emitting layer (64) (where k=1, 2, ..., m in the descending order of wavelength) is smaller than the product ne(k)P(k) of the extraordinary light refractive index ne(k) of the selective reflecting layer (SR) constituting the selective reflection wavelength regions and the helical pitch P(k) and larger than the product no(k)P(k) of the ordinary light reflective index no(k) and the helical pitch P(k), and the condition ne(k-1)P(k-1)<no(k)P(k) is satisfied between the selective reflecting layers (SR) constituting the selective reflection wavelength regions.

An optical system is disclosed which is capable of improving of its contrast characteristic and displaying of images which have a brightness according to the brightness of the use environment. The optical system comprises an optical integrator which divides and recombines the illumination luminous flux in a first axis direction and a light intensity distribution converter which converts the light intensity distribution of the illumination luminous flux in a second axis direction. The optical system further comprises a luminous flux limiting unit which has an aperture. The size of the aperture is changeable in the second axis direction and unchangeable in the first axis direction.

Disclosed herein is a method and apparatus for driving a plasma display panel, which improves contrast characteristics and preventing a low discharge making a cell non-luminous at a specific gray scale. The method for driving a plasma display panel includes the steps of initializing a cell by supplying a first write voltage and an erase voltage to a scanning electrode during a reset interval of the n-th sub-field; initializing the cell by supplying the erase voltage and a second write voltage which is higher than a sustaining voltage and lower than the first write voltage to the scanning electrode during a reset interval of the (n+1)-th sub-field; selecting the cell by supplying the scanning voltage to the scanning electrode and supplying a data voltage to an address electrode during an address interval of each of the n-th and (n+1)-th sub-fields; and alternatively supplying the sustaining voltage to the scanning and sustaining electrodes during a sustaining interval of each of the n-th and (n+1 )-th sub-fields.

An organic light-emitting display apparatus including: a first substrate; a second substrate disposed to face the first substrate; a first electrode disposed between the first substrate and the second substrate and a second electrode disposed to face the first electrode; and an organic light-emitting layer disposed between the first electrode and the second electrode, wherein at least one of the first electrode and the second electrode is a reflective electrode, and an optical property modification layer having at least one optical property modified from that of the reflective electrode is formed on a surface of the reflective layer.