Light Source Unit Time-Division Dimming for Projector Power
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Solution Overview
Problem
Conventional projectors using digital micromirror devices (DMD) face challenges in efficiently managing power consumption and maintaining image quality while projecting color images, particularly in reducing power usage without compromising gradation control and color tone.
Innovation Solution
A light source unit comprising a first light source for emitting light in a first wavelength range, a second light source for emitting light in a second wavelength range, and a processor that controls dimming modes to adjust the quantity of light emitted in time-dividing gradation control periods, including turning off or adjusting the first light source during specific periods to optimize power usage and maintain image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the first light source is continuously operated to maintain image quality and gradation control, then image quality is maintained, but power consumption increases
Solution Approach 1:
The patent implements periodic action by controlling the first light source to operate in a pulsating manner rather than continuously. The light source is turned on and off in synchronization with the gradation control periods of the display device, emitting light only during specific time windows when needed for image projection. This periodic operation significantly reduces power consumption while maintaining image quality because the light source provides sufficient illumination during its active periods, and the display device's persistence of vision fills in the dark periods.
2Use of energy by moving object
If the first light source is turned off during periods when the second light source is emitted, then power consumption is reduced, but gradation control precision may be affected
Solution Approach 1:
The patent applies segmentation by dividing the operation into distinct time-based segments: gradation control periods and non-gradation control periods. During gradation control periods, the first light source is active to provide illumination for precise gradation control. During non-gradation control periods, the first light source is turned off to reduce power consumption while the second light source operates. This temporal segmentation ensures that gradation control precision is maintained when needed, while power consumption is reduced during periods when the second light source provides sufficient illumination.
3Use of energy by moving object
If multiple light sources are operated simultaneously to provide full color range, then color tone is maintained, but power consumption increases
Solution Approach 1:
The patent uses periodic action to control the operation of multiple light sources. The first and second light sources are operated in a time-division manner rather than simultaneously. The first light source operates during gradation control periods while the second light source operates during non-gradation control periods, and vice versa. This periodic alternation ensures that the full color range is available over time to maintain color tone accuracy, while power consumption is reduced because not all light sources are active at the same time.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables reduced power consumption while maintaining image quality and extending battery life, allowing for efficient operation of the projector even when driven by a battery, with the processor controlling the light sources to emit light in a pulsating fashion and adjusting the number of active light sources to minimize power usage without reducing gradation control periods.
Implementation Method 1
a first light source for emitting light in a first wavelength range, a second light source for emitting light in a second wavelength range
Implementation Method 2
a display device configured to perform a gradation control on the light in the first wavelength range and the light in the second wavelength range which are emitted in a time dividing fashion in corresponding gradation control periods to thereby form image light
Data Source
AI summary
A light source unit includes a first light source for first light, a second light source for second light differing from the first light, a display device for performing a gradation control on the first light and the second light which are emitted in a time dividing fashion in corresponding gradation control periods to thereby form image light, and a processor configured to control a first dimming mode for adjusting a quantity of light of the first light source in the gradation control periods of the first light and the second light and a second dimming mode for adjusting the quantity of light of the first light source by performing a turn-off control in at least a partial period of the gradation control period of the first light and adjusting the quantity of light of the first light source in the gradation control period of the second light.