Image Projection Device with Focus-Based Touch Operation Recognition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image projection systems struggle to accurately distinguish between different touch operations such as tap, double-tap, long-tap, drag, and scroll operations on a projected image, as they rely on area ratios of finger shadows which fail to differentiate between single and repeated touches.
Innovation Solution
An image projection device with a focusing imaging unit that captures and processes image data to extract finger or pointer information, using reference data and position data to determine the type of touch operation performed, allowing for precise recognition of input instructions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If area ratio of finger shadow region to finger region is used to detect touch operation, then touch detection can be achieved, but various kinds of operations such as double-tap and long-tap cannot be correctly distinguished
Solution Approach 1:
The patent segments the touch detection process into multiple independent analysis dimensions: (1) shadow area ratio analysis, (2) finger region area analysis, (3) temporal sequence analysis of touch events, and (4) contact duration analysis. By dividing the detection task into these separate segments, the system can correctly identify different operation types such as tap, double-tap, and long-tap based on the combination of results from each segment.
Solution Approach 2:
The patent employs periodic sampling of the imaging unit to capture finger shadow and finger region at multiple time points during the touch operation. By analyzing the temporal sequence and periodic changes in the captured images, the system can distinguish between brief tap operations and sustained long-tap operations, as well as differentiate single tap from double-tap sequences.
2Measurement precision
If the imaging unit captures image data of the projection screen, then finger position can be detected, but it becomes difficult to distinguish between finger staying near the screen and actual touch operations
Solution Approach 1:
The patent introduces the projection screen as an intermediary element that facilitates touch detection. The imaging unit captures images through the projection screen, and the system analyzes the relationship between the finger shadow (projected on the screen) and the finger region (captured in front of the screen). This intermediary approach allows the system to detect both the position and the touch intent by comparing the spatial and temporal relationships between the shadow and the actual finger.
Solution Approach 2:
The patent dynamically adjusts the focus of the imaging unit between the projection screen and the finger region. By changing the focal plane, the system can selectively capture sharp images of either the shadow on the screen or the finger in front of the screen, enabling it to distinguish between fingers that are merely near the screen versus those that are actually performing touch operations.
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 recognition of various touch operations, improving the system's ability to discern input instructions with high precision, even when fingers stay near the projection screen during double-tap operations.
Implementation Method 1
an imaging unit having a function of focusing and configured to image the image projected on the projection screen to acquire image data
Data Source
AI summary
An image projection device which can correctly discern content of touch operation when a user performs various kinds of touch operation on an image projected on a projection screen is provided. An imaging unit is adjusted to come into focus on the projection screen. An image data extracting unit extracts image data in which a finger or the like exists and in which the finger or the like is brought into focus in image data obtained by the imaging unit. An operation determining unit determines content of operation performed with the finger or the like, on the basis of the image data extracted by the image data extracting unit. An input control unit recognizes content of an input instruction corresponding to the operation performed with the finger or the like, on the basis of data relating to the content of the operation performed with the finger or the like, position data of the finger or the like, and reference data for specifying a position and a size of the image projected on the projection screen, and controls a projection unit in accordance with the recognized content of the input instruction.