Color sensor

A sensor for sensing reflective, spectrophotometric, densitometric, calorimetric, self-luminous or radiometric characteristics of a sample, comprising:

• a base having a lower surface:
• a plurality of light sources respectively emitting light of a substantially different wavelength band, mounted to said base such that a first portion of light emitted by said light sources transmits below said lower surface of said base;
• a sample photodetector;
• and
• a first optical assembly, mounted to said lower surface of said base, said first optical assembly being configured to direct said first portion of the light to the sample while excluding direct transmission of said first portion of light to said sample photodetector and being further configured to direct a portion of light reflected from the sample to said sample photodetector;
• said first optical assembly includes an annular collar mounted to said lower surface of said base and positioned over said plurality of light sources and over said sample photodetector, said collar including a plurality of emitter apertures extending axially therethrough, each emitter aperture being provided for a corresponding one of said light sources, and said collar includes a receiver aperture extending axially through said collar so as to provide optical communication between the sample and said sample photodetector;
• said emitter apertures including an upper cylindrical channel and a lower cylindrical channel coaxially aligned with one another and said corresponding emitter axis, the lower cylindrical channel having a diameter smaller than the upper cylindrical channel so as to collimate said first portion of light emitted by said light sources.

A sensor for sensing reflective, spectrophotometric, densitometric, calorimetric, self-luminous or radiometric characteristics of a sample, comprising:

• a base having a lower surface;
• a plurality of light sources respectively emitting light of a substantially different wavelength band, mounted to said base such that a first portion of light emitted by said light sources transmits below said lower surface of said base;
• a sample photodetector;
• and
• a first optical assembly, mounted to said lower surface of said base, said first optical assembly being configured to direct said first portion of the light to the sample while excluding direct transmission of said first portion of light to said sample photodetector and being further configured to direct a portion of light reflected from the sample to said sample photodetector;
• said first optical assembly includes an annular collar mounted to said lower surface of said base and positioned over said plurality of light sources and over said sample photodetector, said collar including a plurality of emitter apertures extending axially therethrough, each emitter aperture being provided for a corresponding one of said light sources, and said collar includes a receiver aperture extending axially through said collar so as to provide optical communication between the sample and said sample photodetector;
• the sensor further comprising a reference photodetector;
• and
• a second optical assembly configured to direct a second portion of light emitted by said light sources to said reference photodetector.

A sensor for sensing reflective, spectrophotometric, densitometric, colorimetric, self-luminous or radiometric characteristics of a sample, comprising:

• a base having a lower surface;
• a plurality of light sources respectively emitting light of a substantially different wavelength band, mounted to said base such that a first portion of light emitted by said light sources transmits below said lower surface of said base;
• a sample photodetector;
• and
• a first optical assembly, mounted to said lower surface of said base, said first optical assembly being configured to direct said first portion of the light to the sample while excluding direct transmission of said first portion of light to said sample photodetector and being further configured to direct a portion of light reflected from the sample to said sample photodetector;
• said first optical assembly includes an annular collar having a central axis mounted to said lower surface of said base and positioned over said plurality of light sources and over said sample photodetector, said collar including a plurality of emitter apertures extending axially therethrough, each emitter aperture being provided for a corresponding one of said light sources, and said collar includes a receiver aperture extending axially through said collar so as to provide optical communication between the sample and said sample photodetector;
• the sensor further comprising a second photodetector, positioned at substantially a 45.degree. angle with respect to said central axis and diametrically aligned with at least one of said light sources to thereby receive a specular component of said light reflected from the sample, whereby said sensor can be used to measure surface gloss of the sample.

A sensor for sensing reflective, spectrophotometric, densitometric, colorimetric, self-luminous or radiometric characteristics of a sample, comprising:

• a base having a lower surface;
• a plurality of light sources respectively emitting light of a substantially different wavelength band, mounted to said base such that a first portion of light emitted by said light sources transmits below said lower surface of said base;
• a sample photodetector;
• and
• a first optical assembly, mounted to said lower surface of said base, said first optical assembly being configured to direct said first portion of the light to the sample while excluding direct transmission of said first portion of light to said sample photodetector and being further configured to direct a portion of light reflected from the sample to said sample photodetector;
• said first optical assembly includes an annular collar mounted to said lower surface of said base and positioned over said plurality of light sources and over said sample photodetector, said collar including a plurality of emitter apertures extending axially therethrough, each emitter aperture being provided for a corresponding one of said light sources, and said collar includes a receiver aperture extending axially through said collar so as to provide optical communication between the sample and said sample photodetector;
• said sample photodetector including a sample output channel;
• the sensor further comprising a processing circuit coupled to said sample output channel, said processing circuit being configured to generate reflective, densitometric, spectrophotometric or calorimetric, self-luminous or radiometric data of said sample based upon data received from said sample channel;
• and
• said processing circuit including a current detector for monitoring current to said light sources, said current detector generating a current signal used by said processing circuit to correct said reflective, densitometric, spectrophotometric or colorimetric data.

A sensor for detecting colorimetric, reflective, densitometric or spectrophotometric, self-luminous or radiometrc characteristics of a sample, comprising:

• a plurality of light emitting diodes for emitting light of substantially different wavelength bands spaced in a predefined spectrum;
• a base having top surface and a bottom surface, a plurality of emitter apertures extending completely therethrough from said top surface to said bottom surface;
• an optical cap having a substantially non-absorbing interior integrating surface mounted over said top surface of said base;
• a reference photodetector mounted to said top surface of said base;
• a sample photodetector mounted to said bottom surface of said base;
• said light emitting diodes being mounted within said cap and adjacent to or in said emitter apertures such that a first portion of light emitted by said light emitting diodes is transmitted through said emitter apertures to a sample and reflected from said sample to said sample photodetector, and such that a second portion of light emitted by said light emitting diodes is transmitted to said integrating surface and directly or indirectly reflected from said integrating surface to said reference photodetector.

A sensor for sensing colorimetric, reflective, densitometric or spectrophotometric characteristics of a sample, comprising:

• a printed circuit board;
• a plurality of light sources, each of said light sources respectively emitting light of a substantially different wavelength band;
• a reference photodetector surface mounted to a surface of said printed circuit board;
• a sample photodetector surface mounted to an opposite surface of said printed circuit board;
• a first optical element adapted to direct a first portion of the light emitted by each of said light sources to said reference photodetector;
• a second optical element adapted to direct a second portion of the light emitted by each of said light sources to the sample;
• and
• a third optical element adapted to direct a portion of light reflected off of the sample to said sample photodetector.

A sensor for detecting calorimetric, reflective, densitometric or spectrophotometric, self-luminous or radiometric characteristics of a sample, comprising:

• a plurality of light sources for emitting light of substantially different wavelength bands spaced in a predefined spectrum;
• a base having top surface and a bottom surface, a plurality of emitter apertures extending completely therethrough from said top surface to said bottom surface;
• a substantially non-absorbing interior integrating surface positioned over said top surface of said base;
• a reference photodetector mounted to said top surface of said base;
• a sample photodetector mounted to said bottom surface of said base;
• said light sources being positioned adjacent to or in said emitter apertures such that a first portion of light emitted by said light sources is transmitted to a sample and reflected from said sample to said sample photodetector, and such that a second portion of light emitted by said light sources is transmitted to said integrating surface and directly or indirectly reflected from said integrating surface to said reference photodetector.