Spectroscopic camera and inspection system

Patent metadata

Field	Value
Publication number	US-11209312-B2
Application number	US-202016829165-A
Country	US
Kind code	B2
Filing date	Mar 25, 2020
Priority date	Mar 26, 2019
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A spectroscopic camera according to the present disclosure includes a spectroscopic section configured by a variable wavelength interference filter that selectively transmits light at a predetermined wavelength and changes the light to transmitted light, a receiving section configured to receive sensitivity information indicating a sensitivity curve in a wavelength region of a predetermined color imaged by an RGB camera, a wavelength-table generating section configured to generate, based on the sensitivity information, a wavelength table indicating a relation between the predetermined wavelength and a transmission time, which is a time for transmitting the transmitted light, an imaging section configured to acquire a spectral image formed by the transmitted light transmitted through the spectroscopic section, and a control section configured to control the spectroscopic section and the imaging section based on the wavelength table.

First claim

What is claimed is:

1. A spectroscopic camera comprising:
a spectroscopic section configured by a variable wavelength interference filter that selectively transmits light at a predetermined wavelength and changes the light to transmitted light;
a receiving section configured to receive sensitivity information indicating a sensitivity curve in a wavelength region of a predetermined color imaged by an RGB camera;
a processor including a spectrum-information generating section configured to generate, based on the sensitivity information, a wavelength table indicating a relation between the predetermined wavelength and a transmission time, which is a time for transmitting the transmitted light;
an imaging section configured to acquire a spectral image formed by the transmitted light transmitted through the spectroscopic section; and
a control section configured to control the spectroscopic section and the imaging section based on the wavelength table.

2. The spectroscopic camera according to claim 1 , wherein the time for transmitting the transmitted light is set based on intensity indicating sensitivity to fixed optical energy, in wavelengths obtained by dividing the wavelength region of the predetermined color, included in the sensitivity information.

3. The spectroscopic camera according to claim 1 , wherein the imaging section captures, for each the predetermined wavelength, spectral image based on the time for transmitting the transmitted light in the spectroscopic section.

4. The spectroscopic camera according to claim 1 , further comprising:
an RGB-image generating section configured to image a defective product using the spectroscopic camera to acquire a defective-product spectral image and generate a defective-product RGB image based on the defective product spectral image; and
a determining section configured to, when a predetermined inspection for the defective product is performed using the defective-product RGB image and the defective product is determined as defective, determine that an RGB camera inspection using the RGB camera satisfies a predetermined criterion, and when the predetermined inspection for the defective product is performed using the defective-product RGB image and the defective product is not determined as defective and when the predetermined inspection for the defective product is performed using a plural-wavelengths defective product image obtained by imaging the defective product using the spectroscopic camera and the defective product is determined as defective, determine that the RGB camera inspection does not satisfy the predetermined criterion and a spectroscopic camera inspection using the spectroscopic camera satisfies the predetermined criterion.

5. The spectroscopic camera according to claim 4 , wherein
the RGB-image generating section images a non-defective product using the spectroscopic camera to acquire a non-defective-product spectral image and generates a non-defective-product RGB image based on the non-defective-product spectral image, and
the determining section sets the predetermined criterion according to a first inspection result, which is a result of the predetermined inspection for a plurality of the defective products performed using the defective-product RGB image, and a second inspection result, which is a result of the predetermined inspection for a plurality of the non-defective products performed using the non-defective-product RGB image.

6. The spectroscopic camera according to claim 5 , wherein the determining section images the plurality of non-defective products using the spectroscopic camera to acquire a plural-wavelengths non-defective product image, calculates a region indicating a distribution of a plurality of third inspection results, which are results of the predetermined inspection for the plurality of non-defective products performed using the plural-wavelengths non-defective product image, performs the predetermined inspection for the plurality of defective products using the defective-product RGB image, calculates a percentage of the first inspection result being included in the region when the plurality of defective products are determined as defective, and, if the percentage is smaller than a set threshold, determines that the predetermined criterion is satisfied.

7. An inspection system comprising the spectroscopic camera according to claim 1 .

Assignees

• Seiko Epson Corp

Inventors

• Aiso Seiji

Classifications

• G01J3/2823 Primary

  Imaging spectrometer · CPC title

• G01J3/26 Primary

  using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters · CPC title

• G06V10/56

  relating to colour · CPC title

• H04N23/67

  Focus control based on electronic image sensor signals · CPC title

• G06F18/22

  Matching criteria, e.g. proximity measures · CPC title