Computer graphics processing and selective visual display system – Plural physical display element control system – Display elements arranged in matrix
Reexamination Certificate
1999-02-16
2001-12-04
Shalwala, Bipin (Department: 2673)
Computer graphics processing and selective visual display system
Plural physical display element control system
Display elements arranged in matrix
C345S077000, C345S211000
Reexamination Certificate
active
06326938
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for controlling power consumption in a display apparatus, particularly a display apparatus having a plasma display panel, and more particularly a display apparatus having an AC-driven plasma display panel. The invention also relates to a display system equipped with such a power consumption control apparatus, and a storage medium storing therein a program for implementing such a power consumption control method.
2. Description of the Related Art
Traditionally, power consumption control in a display apparatus, particularly a display apparatus having an AC-driven plasma display panel (PDP), has been performed by continuously monitoring power consumption that changes with changing display data, and by reducing the brightness of the entire screen when the power consumption exceeds its upper limit value and increasing the brightness when the power consumption drops below its lower limit value.
On the other hand, Japanese Unexamined Patent Publication No. 6-332397 discloses a control method in which display ratio is calculated by cumulatively adding display signals applied externally during a prescribed period, especially, one frame period, and the power consumption is controlled by setting the screen brightness to a value appropriate to the display ratio.
According to the former control method, when the display changes from ALL OFF to ALL ON state, since the screen brightness has been controlled up to the maximum during the ALL OFF period, the entire screen goes into the ALL ON state while the brightness is still controlled at the maximum value and, therefore, the power consumption at this time is higher than the predetermined value and the brightness must be reduced. If the speed with which the brightness is reduced is slow, the displayed image becomes gradually dark even when there is no change in the input display data. If the speed is increased, the image will appear to flash momentarily. In either case, an image quality problem will occur.
Such a problem does not occur with the latter control method since feedback control is not performed in the latter method. Not performing feedback control, however, involves a problem in that the power consumption relative to the display ratio varies from one display panel to another because of manufacturing variations.
SUMMARY OF THE INVENTION
It is, accordingly, an object of the present invention to provide power consumption control that does not induce unnatural changes in brightness even when the ON/OFF state of the display changes abruptly, and that can control power consumption at the desired value regardless of manufacturing variations.
According to the present invention, there is provided a power consumption control method for a display unit, comprising the steps of: calculating a screen load ratio from display data to be applied to the display unit; measuring power consumption in the display unit; and controlling screen brightness based on the calculated load ratio and the measured power consumption.
According to the present invention, there is also provided a power consumption control apparatus for a display unit, comprising: means for calculating a screen load ratio from display data to be applied to the display unit; means for measuring power consumption in the display unit; and means for controlling screen brightness based on the calculated load ratio and the measured power consumption.
According to the present invention, there is also provided a display system comprising: the above-described power consumption control apparatus; a plasma display panel; a drive circuit for driving the plasma display panel; and a control circuit for controlling the drive circuit based on a brightness value supplied from the power consumption control apparatus.
According to the present invention, there is also provided a storage medium storing therein a program for implementing the above-described power consumption control method in a computer.
REFERENCES:
patent: 5298893 (1994-03-01), Sekine
patent: 5315695 (1994-05-01), Saito et al.
patent: 5347294 (1994-09-01), Usui et al.
patent: 5541618 (1996-07-01), Shinoda
patent: 5583527 (1996-12-01), Fujisaki et al.
patent: 5943032 (1999-08-01), Nagaoka et al.
patent: 5956014 (1999-09-01), Kuriyama et al.
patent: 6100859 (2000-08-01), Kuriyama et al.
patent: 6104362 (2000-08-01), Kuriyama et al.
patent: 0 653 740 (1995-05-01), None
patent: 0 655 722 (1995-05-01), None
patent: 2-39092 (1990-02-01), None
patent: 2-91687 (1990-03-01), None
patent: 2-125288 (1990-05-01), None
patent: 6-348227 (1994-12-01), None
patent: 7-44127 (1995-02-01), None
patent: 8-160912 (1996-06-01), None
Ishida Katsuhiro
Kuriyama Hirohito
Tajima Masaya
Takata Kiyoshi
Fujitsu Limited
Osorio Ricardo
Shalwala Bipin
Staas & Halsey , LLP
LandOfFree
Power consumption control in display unit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Power consumption control in display unit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Power consumption control in display unit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2593813