| 摘要 |
In a handheld dataform reader, the usability of the reader is greatly enhanced by monitoring the distance between the dataform reader and the surface bearing a symbol to be read and then changing the dataform reader's targeting image's visual characteristics from one state to another state when the distance between the dataform reader and the surface bearing the symbol is within a predefined optimal focus range of the reader, thus, alerting the user that the dataform reader can be triggered to read the symbol.
|
