Optical Reader Guide Marks for Distance Judgment
Solution Overview
Problem
Optical information reading devices face challenges in determining whether a code symbol is within the readable distance, as the existing methods are inaccurate and difficult to use, especially when the symbol is far away, leading to repeated attempts and wasted time.
Innovation Solution
An optical information reading device that forms guide marks at equal intervals using radially diffused light beams, allowing users to determine if the code symbol is within the readable distance by comparing the interval between guide marks with the code symbol elements, and includes a distance measuring feature to assess the position detection mark.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the distance between the reading device and the code symbol is increased to fit the code symbol within the image pickup range, then the code symbol can be positioned within the image pickup range, but the image of the code symbol becomes too small to be discriminated
Solution Approach 1:
The patent introduces guide marks as an intermediary element between the reading device and the code symbol. These guide marks are formed by light beam irradiation at known intervals and serve as a reference standard. By comparing the apparent size and interval of the guide marks with the code symbol, the system enables accurate distance judgment without requiring the code symbol image itself to be large enough for direct discrimination.
2Manufacturing precision
If the distance between the reading device and the code symbol is decreased to improve image resolution, then the image of the code symbol becomes larger and more discriminable, but the code symbol cannot be fitted within the image pickup range
Solution Approach 1:
The guide marks serve as a reference scale that allows the user to determine the appropriate distance without needing to bring the code symbol close enough for direct visual discrimination. The guide marks provide an intermediate reference that bridges the gap between the two conflicting requirements.
3Area of stationary object
If existing mark-based aiming methods are used to fit the code symbol within the image pickup range, then the code symbol positioning is improved, but there is no indication of whether the code symbol is within the reading depth
Solution Approach 1:
The patent employs different visual states of the guide marks (blurred vs. sharp) to encode distance information. When the reading device is at the appropriate distance, the guide marks appear sharp and clear. When too far away, the guide marks appear blurred. This visual change provides immediate feedback about distance without requiring additional sensors or complex processing.
4Adaptability or versatility
If the upper limit of reading depth is set to accommodate distant subjects, then more subjects can be positioned within the image pickup range, but reading accuracy decreases and repeated attempts increase time consumption
Solution Approach 1:
The guide marks provide immediate visual feedback about the reading distance. By observing whether the guide marks appear sharp or blurred, the user can quickly determine if the distance is appropriate, too close, or too far. This feedback mechanism prevents wasted reading attempts and guides the user to the optimal distance, maintaining high reading accuracy across a wide distance range.
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 users to easily determine if the code symbol is within the readable distance, reducing errors and time wastage by providing a clear indication of the image pickup resolution and distance, thus facilitating accurate decoding.
Implementation Method 1
an irradiator configured to irradiate the subject to be read to form the guide mark indicating an image pickup resolution of the image pickup portion
Data Source
AI summary
In an optical information reading device configured to read a code symbol on a subject to be read by acquiring an image of the subject to be read with an image pickup portion and analyzing the image, a laser light source and an irradiation optical system is provided as an irradiator configured to irradiate the subject to be read to form a guide mark indicating an image pickup resolution of the image pickup portion. It is preferable that the irradiator is configured to emit a plurality of radially diffused light beams so as to form the guide mark at equal intervals on the subject to be read.