X-rite Gmbh

Thomas J Boes

Bernard J Berg

Mark A Cargill

Douglas V Baker

Steven Henry Peterson

Timothy R Friend

David R Bowden

Marc D Zuiderveen

Patrick S Rood

Lawrence D Zandstra

A spectrophotometer providing a sample measurement area of selectable size. The spectrophotometer includes a sphere defining a sample station, a lamp to illuminate the interior of the sphere and therefore the sample station, a color measurement engine including an aperture directed toward the sample station, and a measurement area size selector. The size selector includes a movable plate defining two or more holes of different sizes. The plate can be moved so that only one of the holes is aligned with the aperture to control the size of the measurement area sampled by the color measurement engine.

Spectrophotometer with selectable measurement area

A colorimeter for reading color bars of printed sheets or the like includes a longitudinally extending base including a paper stop along which a sheet to be tested for color may be positioned. An autonomously operating colorimeter head is moved along the base in a direction parallel to the edge of the sheet by means of an electric motor mounted on the base and driving an helical thread lead screw engaging an X-axis carriage supporting the head. The head is moved by operation of the lead screw in a direction parallel to the edge of the sheet, referred to as the direction of the X-axis. The head includes an electric motor and a Y-axis transport supporting an optics unit. The optics unit is moved within the head in a direction parallel to a Y-axis, extending perpendicularly to the X-axis. The optics unit is preferably a spectrophotometer including a rotating wheel provided with a plurality of individual filters, spaced apart along the periphery of the wheel. The individual filters each pass light of a predefined wavelength onto a single photodetector and the signal derived from the photodetector is integrated over a period of time to provide an output signal representative of the intensity of a particular wavelength.

Scanning colorimeter with x-y drive

A spectrophotometer apparatus (200) is adapted to provide spectral reflectance measurements of an object sample (236) under test, particularly optical characteristics of colored surfaces comprising metallic or pearlescent particles. The apparatus (200) comprises a source light (226) and a reflection optics assembly. Signals representative of reflected light are analyzed and data is generated representative of the spectral response characteristics of the object sample (236). The apparatus (200) employs a plurality of fiber optic bundles (248, 250, 252) for receiving light reflected from the object sample (236), with each of the fiber optic bundles (248, 250, 252) being positioned at one of a corresponding plurality of fixed angles different from the angle of illumination of the source light (226). Reflectance is measured at each angle by sequential switching such that light is impaired from being received by all but a subset of the plurality of multiple angles. Light received from the fiber optic bundles is transferred to a single array of integral interference-filter/photodiode devices (284) which modulate the light and determine the spectral characteristics thereof. With the use of fiber optic devices, a single source of illumination and a single optical detector arrangement, the spectrophotometer apparatus (200) is employed within an optimally small packaging configuration, and the apparatus (200) can be maintained in a portable mode while maintaining relatively high accuracy and repeatability.

Multiangular color measuring apparatus

A portable spectrophotometer includes a small-diameter optical sphere as well as optical detectors and signal processing and display circuitry which allows the instrument to be taken to an object to be measured and which provides a readout of color values at the portable instrument. The instrument is capable of providing specular-included and specular-excluded color readings simultaneously. The interior of the integrating sphere is coated with a highly reflective, color-absorbing material, and light from an incandescent lamp is diffused within the sphere prior to reaching the object to be measured. The sphere is provided with a first aperture which receives spectrally-included light and which is positioned to absorb a spectral component of the diffused source light. A second aperture positioned at a corresponding angular position with respect to the object measures specular-excluded light, excluding the specular component absorbed by the first aperture. Light detected from the first aperture is analyzed at a plurality of wavelengths obtained by the use of interference filters, and the light obtained from the second aperture is analyzed at one of the plurality of wavelengths. By appropriately combining the specular-included and specular-excluded at one wavelength, a value for the specular component is derived. Since this value is a theoretical constant, it is used to derive a specular-excluded reading from each of the specular-included readings at the different wavelengths.

Portable spectrophotometer

A densitometer apparatus (410) is disclosed and is adapted to provide color density measurements of object samples. The densitometer apparatus (410) comprises a source light (580) for projecting light toward an object sample comprising a control strip (588, 620). A reflection optics assembly (576) is adapted to measure light density reflected from the object sample when the object sample is in the form of a paper control strip. A transmission optics assembly (618) is adapted to measure transmission density of light rays projected through the object sample when the object sample is in the form of a film control strip. A motor assembly (426) operating with a drive wheel assembly (434) and idler wheel assembly (440) automatically moves the object sample (588, 620) through the apparatus (410) adjacent the source light (580). A pair of guides (468, 470) are selectively adjustable by the operator to control movement of the object sample (588, 620) through the apparatus (410). In response to input from a key switch assembly (492) activatable by the operator, the apparatus (410) is adapted to perform various color density measurement and calibration functions, and display appropriate information to the operator through the use of a visual display (490).

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Grandville, MI, United States of America

Thomas J Boes