Automatic brightness control system and method for a display device using a logarithmic sensor
AssigneeVisteon Global Technologies, Inc.
InventorPaul Fredrick Luther Weindorf
Life of this patent
Estimating the term…
Abstract
This invention provides an automatic brightness control system for display devices, which may have a lighted display, a sensor, and control circuitry. The sensor logarithmically generates a first signal in response to the ambient light near the lighted display. The control circuit selects a display luminance from one or more luminance adjustment sequences having essentially constant ratio steps. The display luminance is a fractional power function of the ambient light near the display. The fractional power function may be adjusted by a constant luminance ratio offset.
Claims63
A display device having an automatic brightness control system, comprising:
- a lighted display;
- a sensor disposed to logarithmically sense ambient light near the lighted display;
- and
- control circuitry connected to receive a first signal from the light sensor, the control circuitry connected to provide a display luminance to the lighted display,
- where the control circuitry selects the display luminance from at least one luminance adjustment sequence,
- where each luminance adjustment sequence has a plurality of luminance values with constant ratio steps, and
- where the display luminance is controlled by a transfer function that includes a term having a power relation to the ambient light near the lighted display and where an exponent of the term is a fraction.
A display device having an automatic brightness control system, comprising:
- a lighted display;
- a sensor disposed to logarithmically sense ambient light near the display panel;
- a user interface;
- and
- control circuitry connected to receive a first signal from the sensor, the control circuitry connected to receive at least one user brightness selection from the user interface, the control circuitry connected to provide a display luminance to the lighted display,
- where the control circuitry selects the display luminance from at least one luminance adjustment sequence,
- where each luminance adjustment sequence has a plurality of luminance values with constant ratio steps,
- where the display luminance is controlled by a transfer function that includes a term having a power relation to the ambient light near the lighted display and where an exponent of the term is a fraction and,
- where the transfer function is adjusted by a constant ratio offset based on the at least one user brightness selection.
A method for controlling the brightness of a display device, comprising:
- (a) logarithmically generating a first signal in response to the ambient light associated with a lighted display;
- (b) selecting a display luminance from at least one luminance adjustment sequence, each luminance adjustment sequence having a plurality of luminance values with constant ratio steps;
- and
- (c) providing the display luminance to a lighted display, where the display luminance is controlled by a transfer function that includes a term having a power relation to the ambient light associated with the lighted display where an exponent of the term is a fraction.
A method for controlling the brightness of a display device, comprising:
- (a) determining at least one user brightness selection;
- (b) logarithmically generating a first signal in response to the ambient light near a lighted display;
- (c) selecting a display luminance value from at least one luminance adjustment sequence, each luminance adjustment sequence having a plurality of luminance values with constant ratio steps;
- (d) providing the display luminance to the lighted display, where the display luminance is controlled by a transfer function that includes a term having a power relation to the ambient light near the lighted display where an exponent of the term is a fraction;
- and
- (e) adjusting the transfer function by a constant luminance ratio offset based on the at least one user brightness selection.
Dependencies are inferred from the claim text.