| 摘要 |
<p>A visual sensor (110) has a first portion (115) and a second portion (120). The sensor is able to detect the state of one or more imaging parameters such as exposure beam intensity, exposure beam pulse width modulation, exposure beam focus, image balance, spot ellipticity, sidelobe size, shape, and intensity, media gamma, edge sharpness, dot gain, uniformity, ink receptivity, physical changes in the media, pattern dependent effects such as dot gain or tone resolution compared to the type of halftone used, and sensitivity to calibrated position or exposure errors. The first image portion (115) has a first imaging characteristic, and the second image portion (120) has a second imaging characteristic. Imaging characteristics are characteristics of an image, including, but not limited to apparent density level, tint, colour, reflectivity, absorption, granularity or microstructure, size, shape, distribution, degree of randomness, structure, edge sharpness, and depth or dimension. One of the portions is less sensitive to one or more imaging parameters than the other portion so that the first image portion (115) and the second image portion (120) appear substantially similar at a desired range of imaging parameters, and appear different otherwise. The imaging characteristic of the first portion (115) is distinguishable from the imaging characteristic of the second (120) for one or more ranges of one or more imaging parameters, and is not distinguishable for the alternate range(s) of the one or more imaging parameters. A range can be a particular imaging parameter value, or a range that excludes one or more imaging parameter values.</p> |
