Power supply circuit for display unit, method for controlling same, display unit, and electronic apparatus
AssigneeSeiko Epson Corporation
InventorTakashi Kurumisawa
Life of this patent
Estimating the term…
Abstract
The invention prevents or substantially prevents the brightness from changing according to the number of pixels that are turned on in a display. A power supply circuit calculates the total number of pixels that are turned on using ON/OFF data RD that stipulates the ON/OFF state of the pixels 1400 and controls the output impedance of a power supply voltage that is transmitted to a display panel, so that the output impedance becomes lower as the calculated total number of the pixels increases.
Claims8
A power supply circuit for a display unit that transmits a power supply voltage to a display panel having pixels that are turned on when the power supply voltage is energized and that are turned off when the power supply voltage is non-energized, the power supply circuit comprising:
- a calculation circuit to calculate a total number of pixels that are turned on in the display panel;
- a voltage generation circuit to make the output impedance of the power supply voltage variable and to transmit the power supply voltage to the display panel;
- and
- a control circuit to control the output impedance of the voltage generation circuit so that the output impedance becomes lower as the total number of pixels calculated by the calculation circuit increases.
A method for controlling a power supply circuit for a display unit to control transmission of a power supply voltage to a display panel having pixels which have a brightness that is stipulated according to an energization state of the power supply voltage, the method comprising:
- calculating a load on the display panel from data that stipulates the brightness of the pixels;
- and
- controlling an output impedance of a voltage generation circuit to transmit the power supply voltage to the display panel so that the output impedance is reduced as the calculated load increases.
A display unit, comprising:
- a display panel having pixels that are aligned, and that are turned on when a power supply voltage is energized and that are turned off when the power supply voltage is non-energized;
- a calculation circuit to calculate the total number of the pixels that are turned on in the display panel;
- a voltage generation circuit to make the output impedance of the power supply voltage variable and to transmit the power supply voltage to the display panel;
- and
- a control circuit to control the output impedance of the voltage generation circuit so that the output impedance becomes lower as the total number of the pixels calculated by the calculation circuit increases.
Dependencies are inferred from the claim text.