Projector Distance Measurement Using Segmented Laser Arrays
Solution Overview
Problem
Existing projectors face challenges in accurately measuring distances to a screen and calculating the tilt angle for keystone distortion correction, which is essential for ensuring a clear and undistorted image projection.
Innovation Solution
A projector with a distance measuring unit that uses multiple laser units to irradiate light onto a screen and a light receiving element to calculate distances and tilt angles, allowing for precise correction of image distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a distance measuring device is provided on the projector to measure distance to the screen, then the projection distance can be measured, but the measurement precision is insufficient for accurate keystone distortion correction
Solution Approach 1:
The distance measuring device is divided into multiple independent laser units (first, second, third laser units) that emit light rays to different points on the screen. Each unit independently measures distance to a specific point, and the control unit processes these individual measurements to calculate the tilt angle. This segmentation enables precise multi-point distance measurement while keeping each individual laser unit simple and manageable.
Solution Approach 2:
The control unit acts as an intermediary that receives distance information from multiple laser units, processes this data, and calculates the tilt angle of the screen. It mediates between the raw distance measurements and the final distortion correction parameters, enabling accurate keystone correction through mathematical processing of the collected distance data.
2Measurement precision
If multiple light ray units are used to measure distances to multiple points on the screen, then the tilt angle can be calculated accurately, but the device complexity increases
Solution Approach 1:
Multiple laser units perform the same basic function of emitting light rays and measuring distance, but to different points on the screen. This multi-functionality allows the system to gather comprehensive spatial information needed for accurate tilt angle calculation. Each laser unit is identical in structure but serves different measurement purposes, enabling precise screen orientation detection.
Solution Approach 2:
The system uses the projector's own light source and optical components for distance measurement rather than requiring external measurement devices. The laser units are integrated into the projector body, and the control unit processes the measurement data internally to calculate tilt angle and provide distortion correction parameters, making the system self-sufficient.
3Manufacturing precision
If distance measurement is performed to correct keystone distortion, then image quality improves, but the ease of operation decreases due to additional setup requirements
Solution Approach 1:
The control unit automatically receives distance measurement data from the laser units, calculates the screen tilt angle, and determines the appropriate distortion correction parameters. This automatic feedback loop eliminates the need for manual tilt angle measurement and correction setup, allowing the projector to self-adjust for optimal image quality based on the actual screen position and orientation.
Solution Approach 2:
The system performs distance measurements to multiple screen points and calculates tilt angle information before projecting the final image. By preliminarily gathering spatial information and computing correction parameters in advance, the system prepares the distortion correction data needed for high-quality image projection, simplifying the user setup process.
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
Enables accurate measurement of distances and tilt angles, facilitating effective distortion correction and ensuring a clear, undistorted image projection by using a combination of laser units and a light receiving element within the projector.
Implementation Method 1
a light receiving element for receiving light rays reflected on a surface of the screen
Implementation Method 2
a light receiving element for receiving light rays reflected on a surface of the screen
Data Source
AI summary
A projector is provided which includes a distance measuring unit which can accurately measure distances to a plurality of points on a surface of a screen using light rays. The projector of the invention has the distance measuring unit for measuring distances to the plurality of points on the surface of the screen, which includes a plurality of light ray units for irradiating light rays onto the screen and one light receiving element for receiving the light rays which are reflected on the surface of the screen, and a tilt angle calculation unit for calculating a tilt angle of the screen relative to the projector based on the distances to the plurality of points on the surface of the screen which are measured by the distance measuring unit.