Spectrometer apparatus for self-calibrating color imaging apparatus
AssigneeEastman Kodak Company
InventorJames R. Milch
Life of this patent
Estimating the term…
Abstract
Spectrometer apparatus, for self-calibrating a color image scanner of the line scanner or area scanner type, comprises a member, having an optical slit, movable into position on an optical axis of the scanner between its polychromatic light source and its focusable lens in a plane occupied by a color image when it is scanned. A diffraction grating is similarly movable onto the optical axis, a given distance from an image sensor of the scanner. The light source illuminates the slit and the diffraction grating disperses transmitted polychromatic light according to its wavelength, forming duplicate spectra off-axis across respective halves of the image sensor, with longer wavelengths being diverted to respectively higher angles.
Claims11
Spectrometer apparatus for measuring the spectral characteristics of color imaging apparatus of the type including a solid state image sensor having multiple pixels, and optical apparatus for projecting light, transmitted via a color image, along an optical axis for illuminating pixels of said image sensor, said spectrometer apparatus comprising:
- (a) a light source;
- (b) a member, defining an optical slit, positionable on the optical axis between said light source and the optical apparatus in a plane occupied by a color image when it is illuminated;
- and
- (c) a diffraction grating positionable on the optical axis between the optical apparatus and the image sensor to disperse light, projected by the optical apparatus, onto the image sensor, the magnitude and the location of the light impinging upon the image sensor varying as a function of optical characteristics of the color imaging apparatus including the spectral content of said light source and the spectral transmissivity characteristics of the optical apparatus and the image sensor.
Spectrometer apparatus for measuring the spectral characteristics of color imaging apparatus of the type having a source of polychromatic light for illuminating a color image, a solid state image sensor having multiple pixels, and optical apparatus for projecting polychromatic light transmitted via the color image along an optical axis for illuminating pixels of said image sensor, said spectrometer apparatus comprising:
- (a) a member, defining an optical slit, positionable on the optical axis between the light source and the optical apparatus in a plane occupied by a color image when it is illuminated;
- and
- (b) a diffraction grating positionable on the optical axis a given distance from the image sensor to disperse spectral components of the polychromatic light, transmitted by the optical apparatus, onto individual pixels of the image sensor, the respective magnitudes of the spectral components varying as a function of optical characteristics of the color imaging appratus including the spectral content and sensitivity of the light source and the spectral transmissivity characteristics of the optical apparatus and the image sensor.
Spectrometer apparatus for calibrating a color image scanner of the type having a source of polychromatic light for illuminating a color image to be scanned, a solid state image sensor having multiple pixels, and lens apparatus for projecting polychromatic light transmitted via the color image along an optical axis for simultaneously illuminating pixels of said image sensor, said spectrometer apparatus comprising:
- (a) a member, defining a narrow optical slit, positionable on the optical axis during a calibrating mode of operation between the light source and the lens apparatus in a plane occupied by a color image when it is scanned;
- and
- (b) a diffraction grating positionable on the optical axis during the calibration mode of operation a given distance from the image sensor to disperse spectral components of polychromatic light, projected by the lens apparatus, onto individual pixels of the image sensor, the respective magnitudes of the spectral components varying as a function of the optical characteristics of the color image scanner including the spectral content and sensitivity of the light source and the spectral transmissivity characteristics of the lens apparatus and the image sensor.
Dependencies are inferred from the claim text.