Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Minoru Takeda

Kenji Ogawa

Shigeo Kigo

Keiji Akamatsu

Hidehiko Shoji

Yasuaki Mutou

Taiichi Saeki

Hiroshi Ibaraki

Takahiko Origuchi

Katsumi Adachi

Susumu Tsujihara

Katsuhiko Yamamoto

Shinichiro Hashimoto

Takeru Yamashita

Shinji Masuda

Yohei Koshio

Katsumi Mitsuda

Toshiro Matsuura

Takeshi Kureha

Nobuhiko Nakamura

Hiroko Yamamoto

Taku Okada

Tooru Kawase

Teruo Kataoka

Akira Yawata

In a driving method of a panel, one field period is formed by arranging a plurality of subfields that have an initializing period for causing initializing discharge in a discharge cell, an address period for selectively causing address discharge in the discharge cell, and a sustain period for causing as many sustain discharges as the number corresponding to luminance weight in the discharge cell. One field period is formed by arranging a plurality of subfield groups having a plurality of subfields whose luminance weights monotonically increase. A holding period when discharge is not caused is disposed before the head subfield belonging to at least one subfield group of the plurality of subfield groups. In the initializing period of the head subfield belonging to at least one subfield group, an initializing operation of causing initializing discharge is performed in the discharge cell where the sustain discharge has been performed in the sustain period of the immediately preceding subfield.

Method for driving a plasma display panel by using a holding period between subfield groups

In a driving method of a panel, one field period is formed by arranging a plurality of subfields that have an address period for selectively causing address discharge in a discharge cell, and a sustain period for causing as many sustain discharges as the number corresponding to luminance weight in the discharge cell. One field period is formed by arranging a plurality of subfield groups having a plurality of subfields whose luminance weights monotonically increase. In the discharge cell for causing address discharge in a certain subfield other than the head subfield in each subfield group, address discharge is caused even in the head subfield.

Method for driving a plasma display panel using subfield groups

A plasma display panel; a scan electrode drive circuit for generating a gently decreasing downward inclined waveform voltage in an initializing period, a gently increasing first inclined waveform voltage, and a second inclined waveform voltage having a steeper gradient than the first inclined waveform voltage and decreasing immediately after the increasing waveform voltage reaches a predetermined potential in the last part of the sustain period. The lowest voltage in the downward inclined waveform voltage is switched at a first voltage, a second voltage higher than the first voltage and a third voltage higher than the second voltage to generate a downward inclined waveform voltage. The lowest voltage is switched according to the detected temperature to generate the downward inclined waveform voltage.

Plasma display device and method for controlling an amplitude of a waveform used for driving a plasma display panel based on temperature

A plasma display device and a driving method thereof are provided. The plasma display device has a panel having a plurality of discharge cells including a display electrode pair that is formed of a scan electrode and a sustain electrode, and a temperature detecting circuit for detecting the ambient temperature of the panel and outputting the detected temperature. In the driving method, an unusual charge erasing period when a rectangular waveform voltage is applied to the scan electrode is disposed between the initializing period and address period of at least one of a plurality of subfields, and the number of subfields having the unusual charge erasing period is controlled based on the detected temperature detected by the temperature detecting circuit.

Plasma display device and method for driving the same

In the initializing period of each of sub-fields comprising one field, one of all-cell initializing operation and selective initializing operation is performed. The all-cell initializing operation causes initializing discharge in all the discharge cells for displaying an image. The selective initializing operation selectively causes initializing discharge only in the discharge cells subjected to sustaining discharge in the preceding sub-field. Provided in the all-cell initializing period is an abnormal charge erasing part in which application of a rectangular waveform voltage to the scan electrodes causes self-erasing discharge in the discharge cells having excessive wall voltage accumulated therein.

Method of driving plasma display panel

A panel driving method has, in one filed time period, an all-cell initializing subfield for causing initializing discharge in all discharge cells for displaying an image in the initializing period, and a selection initializing subfield for selectively causing initializing discharge in the discharge cell that has caused sustaining discharge in the last subfield in the initializing period. The number of all-cell initializing subfields can be increased and decreased, and the initializing voltage for causing initializing discharge in the all-cell initializing subfield can be varied. At least one of the number of all-cell initializing subfields and the initializing voltage of the all-cell initializing subfields in one field is controlled based on the accumulation of the panel power-on time.

Method of driving plasma display panel, and plasma display device

One field is formed of a plurality of sub-fields, and each one of the sub-fields includes an initializing period, addressing period, and sustained period. The sub-field is one of an entire-cell initialization sub-field or a selective-cell initialization sub-field. When the entire initialization sub-field is switched to the selective one or vice versa, an initializing voltage which generates initializing discharge in the entire initialization sub-field is controlled. This control allows varying the number of the entire initializations and stabilizing address discharge in a plasma display panel, and at the same time, making the black luminance inconspicuous for improving the picture quality.

Initialization waveforms with different voltages are applied respectively to a predetermined subfield with a small number of sustain pulses, and a subfield with the smallest number of sustain pulses in subfields other than the predetermined subfield. This offers a plasma display device that achieves a correct write operation in all discharge cells even if discharge interference occurs between adjacent cells, and also achieves a high contrast.

Plasma display device

An image display method for allowing an image display device having a large number of pixels arrayed in a planar form to perform an image display by forming one field period from plural sub-fields for which luminance weights to be displayed are determined, and choosing plural luminances among displayable luminances as luminances for display by combining the luminance weights of the sub-fields, so that the respective pixels are controlled not to emit light or to emit light in each sub-field correspondingly to the luminances for display to be displayed. At least one threshold value is set, and when a pixel is allowed to emit light at a luminance for display at or higher than a first threshold value, which is the smallest threshold value, the pixel is controlled not to emit light constantly or to emit light constantly in a sub-field having the smallest luminance weight.

Image display method

In the initializing period of each of sub-fields comprising one field, one of all-cell initializing operation and selective initializing operation is performed. The all-cell initializing operation causes initializing discharge in all the discharge cells for displaying an image. The selective initializing operation selectively causes initializing discharge only in the discharge cells subjected to sustaining discharge in the preceding sub-field. During initializing discharge using scan electrodes as anodes, and using sustain electrodes and data electrodes as cathodes in the all-cell initializing period, applying, to the data electrodes, a voltage for delaying discharge using the data electrodes as the cathodes, after discharge using the sustain electrodes as the cathodes.

To provide a PDP display device and a drive method which use a set-up pulse having a portion that drops in voltage at a rate of 2V/&mgr;sec or more, whereby the occurrence of discharge errors in a sustain period can be suppressed even when wall charges are not sufficiently erased in an erase period and excess wall charges remain on some or all electrodes in a set-up period. To this end, the drop portion of the set-up pulse applied to a scan electrode group is set after a pulse applied to a sustain electrode reaches a voltage which does not cause a discharge between the sustain and scan electrodes. As a result, the occurrence of discharge errors in the sustain period is suppressed, without prolonging the set-up period.

Plasma display panel display device and drive method

A television receiver converts a television signal of a standard television system currently employed into a signal at a horizontal scanning frequency of n (an integer of 2 or more) times that of the original television signal, so that it can visually reproduce any one of a television signal of the standard television system and a television signal of a second television system, which has a horizontal scanning frequency of about n times that of the television signal of the standard television system. When receiving the television signal of the standard television system, the horizontal deflection circuit operates at a horizontal scanning frequency n times that of the standard television system. When receiving the television signal of the second television system, it operates at the horizontal scanning frequency of the second television system. For the reproduction of the converted signal with the n times horizontal scanning frequency, the interval between the adjacent scanning lines may properly be adjusted by moving them at the horizontal scanning period of the standard television system in the vertical scanning direction.

Television receiver

A system for compensating image contour by modulating a scanning velocity in accordance with a video signal is disclosed, in which a mean current dissipated in a driving power amplifier is detected to control a gain of an amplifier in a preceding stage for suppressing the increase of power dissipation in the power amplifier when a video signal having many noises is received. The preceding stage amplifier is provided with a saturation characteristic to enhance the effect of contour compensation at a small amplitude signal and eliminate over compensation of image contour at a large amplitude signal. The combination of the saturation characteristic and the gain control further enhances the effect of suppression of power dissipation.

Scanning velocity modulation system

An apparatus for converging three electron beams accurately on the picture tube screen of a color television reproducing system. In this apparatus, a controlled pulse is produced from a deflection drive pulse which is supplied to the reproducing system as one of several synchronizing pulses separately from the color component signals, or is produced from a synchronizing pulse which is separated from the composite signal in the reproducing system. Desired tilt controlled parabola currents are produced from the sawtooth voltage which is generated from the controlled pulse the position of the leading edge and pulse width of which are preferably set for adjusting the phase of the convergence fields relative to that of the deflection field and to avoid causing a distortion of the resultant parabola currents at the end of the blanking period.

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Osaka, Japan

Minoru Takeda