Abstract:
A hand-held battery operated densitometer for identifying and analyzing printed targets (12) is provided which automatically determines whether an unprinted substrate, a solid black, a muddy magenta solid, an overprint, a solid color, or a halftone has been detected. Referenced density values measured through red, green, blue and visual optical filters (20a-d) for an overprint and the first and second down colors are used to determine and display percent trap. Referenced density values for halftone and corresponding solid targets are used to determine and display percent dot area. Referenced density values for solid targets may also be displayed. The printing process is adjusted based upon the displayed solid densities, percent trap and percent dot area.
Abstract:
A remote reading spectrophotometer (10) is provided having the capability to accurately measure spectral reflectance at relatively long sample distances. A first illumination optics arrangement (14) assures uniform illumination to a portion of the sample and a second optical means (20) focuses the reflected image of part of the illuminated sample onto a polychromator (22). Reference beam means are provided so that the polychromator sequentially measures the spectral characteristics of the reference beam and the sample. Continuous monitoring of the illumination at select wavelengths provides illumination normalization data so that a microprocessor (40) can normalize the illumination and compare the reference beam and sample measurements to accurately determine the spectral reflectance characteristics of the sample. Angular and raster scanning capability is also provided.
Abstract:
A remote reading spectrophotometer (10) is provided having the capability to accurately measure spectral reflectance at relatively long sample distances. A first illumination optics arrangement (14) assures uniform illumination to a portion of the sample and a second optical means (20) focuses the reflected image of part of the illuminated sample onto a polychromator (22). Reference beam means are provided so that the polychromator sequentially measures the spectral characteristics of the reference beam and the sample. Continuous monitoring of the illumination at select wavelengths provides illumination normalization data so that a microprocessor (40) can normalize the illumination and compare the reference beam and sample measurements to accurately determine the spectral reflectance characteristics of the sample. Angular and raster scanning capability is also provided.
Abstract:
A hand-held battery operated densitometer for identifying and analyzing printed targets (12) is provided which automatically determines whether an unprinted substrate, a solid black, a muddy magenta solid, an overprint, a solid color, or a halftone has been detected. Referenced density values measured through red, green, blue and visual optical filters (20a-d) for an overprint and the first and second down colors are used to determine and display percent trap. Referenced density values for halftone and corresponding solid targets are used to determine and display percent dot area. Referenced density values for solid targets may also be displayed. The printing process is adjusted based upon the displayed solid densities, percent trap and percent dot area.
Abstract:
A dual reading head transmission/reflection densitometer is disclosed offering superior performance and reduced manufacturing costs. The instrument employs two separate measuring heads (1, 3), each containing its own collection optical system mounted in a single swing arm. Reflected or transmitted light is transmitted from the appropriate measuring head through fiber optic leads (6, 17) to a bifurcated fiber bundle (38) and then to the photodetector assembly (47).