Multi-angle colorimeter that suppresses the influence of an inclination of a reference angle on a colorimetric result

Patent metadata

Field	Value
Publication number	US-10989593-B2
Application number	US-201615738265-A
Country	US
Kind code	B2
Filing date	Jun 14, 2016
Priority date	Jun 26, 2015
Publication date	Apr 27, 2021
Grant date	Apr 27, 2021

Abstract

First and second measurement operations are performed according to each of a plurality of geometric conditions while keeping the geometric condition. In the first measurement operation, illumination light is radiated from a first light radiating position toward a measurement target position and spectroscopic measurement is performed on reflected light traveling from the measurement target position toward a first light receiving position. In the second measurement operation, illumination light is radiated from a second light radiating position toward a measurement target position and spectroscopic measurement is performed on reflected light traveling from the measurement target position toward a second light receiving position. The two spectroscopic measurement results are averaged. The second light radiating position and the second light receiving position are respectively disposed symmetrical to the first light radiating position and the first light receiving position with respect to a reference axis.

First claim

The invention claimed is:

1. A multi-angle colorimeter comprising:
a first illuminator configured to illuminate light toward a measurement target position at a certain angle;
a second illuminator configured to illuminate light symmetrically to illumination by the first illuminator with respect to a reference axis passing through the measurement target position;
a first light receiver that is disposed facing the measurement target position and is configured to receive light that is illuminated by the first illuminator and reflected at the measurement target position at the certain angle;
a second light receiver that is disposed facing the measurement target position and is configured to receive light that is illuminated by the first illuminator and reflected at the measurement target position at an angle different from a light receiving angle of the first light receiver;
a third light receiver that is disposed facing the measurement target position and is configured to receive light that is illuminated by the second illuminator and reflected at the measurement target position at an angle symmetric to a light receiving angle of the first light receiver with respect to a reference axis passing through the measurement target position;
a fourth light receiver that is disposed facing the measurement target position and receives light that is illuminated by the second illuminator and reflected at the measurement target position at an angle symmetrical to a light receiving angle of the second light receiver with respect to a reference axis passing through the measurement target position;
one light receiving sensor configured to output a signal in accordance with light received by each light receiver;
a plurality of light guiding members configured to guide the light received by each light receiver to the one light receiving sensor;
a switch configured to switch the light from the plurality of light guiding members to the light receiving sensor subsequently in an order of light reception by the first light receiver, the light reception by the third light receiver, the light reception by the second light receiver, and the light reception by the fourth light receiver; and
a calculator configured to calculate a measurement result based on a signal in accordance with light received by the first light receiver and a signal in accordance with light received by the third light receiver, and to calculate a measurement result based on a signal in accordance with light received by the second light receiver and a signal in accordance with light received by the fourth light receiver.

2. The multi-angle colorimeter according to claim 1 , wherein
the calculator is further configured to calculate a measurement result based on an average of a signal in accordance with the light received by the first light receiver and a signal in accordance with the light received by the third light receiver, and to calculate a measurement result based on an average of a signal in accordance with the light received by the second light receiver and a signal in accordance with the light received by the fourth light receiver.

3. The multi-angle colorimeter according to claim 2 wherein each of the light guiding members has:
at least one optical fiber;
a light incident port connected to a respective one of the light receivers; and
a light emitting port connected to the one light receiving sensor.

4. The multi-angle colorimeter according to claim 3 , wherein
the switch further comprises a light shielder configured to selectively allow passage of light toward the light receiving sensor from one light incident port of the plurality of light incident ports, and to shield residual light toward the light receiving sensor from residual light incident ports other than the one light incident port among the light incident ports.

Assignees

• Konica Minolta Inc

Inventors

• Iida Shinichi
• Teraoka Yoshitaka

Classifications

• G01J3/50 Primary

  using electric radiation detectors · CPC title

• G01J3/36

  Investigating two or more bands of a spectrum by separate detectors · CPC title

• G01J3/504

  Goniometric colour measurements, for example measurements of metallic or flake based paints · CPC title

• G01J3/10 Primary

  Arrangements of light sources specially adapted for spectrometry or colorimetry · CPC title

• G01J3/501

  Colorimeters using spectrally-selective light sources, e.g. LEDs · CPC title