Imaging system and imaging method that perform a correction of eliminating an influence of ambient light for measurement data

Patent metadata

Field	Value
Publication number	US-9531950-B2
Application number	US-201514632249-A
Country	US
Kind code	B2
Filing date	Feb 26, 2015
Priority date	Mar 13, 2014
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

An imaging system using a transmission light source unit includes a sensor unit (imaging unit) that detects light emitted from a light source unit, a storage unit that stores correction data for eliminating the influence of ambient light, and a signal processing unit that performs correction for eliminating the influence of ambient light on measurement data, which is obtained by measurement using a subject, based on the correction data. The correction data is calculated based on a difference between first reference data obtained by imaging in a state where a light shielding plate having an opening is disposed between the light source unit and the sensor unit and second reference data obtained by imaging in a state where no light shielding plate is disposed.

First claim

What is claimed is:

1. An imaging system that images a subject by irradiating the subject with light and detecting light transmitted through the subject, comprising:
a light source unit;
a sensor that detects light emitted from the light source unit;
a storage that stores first correction data calculated based on a difference between first reference data and second reference data, the first reference data being detected by emitting the light with a light shielding plate having an opening placed between the light source unit and the sensor unit and being detected in an opening corresponding region, which is a region in a detection surface of the sensor unit corresponding to the opening of the shielding plate, the second reference data being detected in the opening corresponding region by emitting the light without placing the light shielding plate; and
a signal processor programmed to perform first correction of eliminating an influence of ambient light for measurement data, which is obtained by measurement using the subject, based on the first correction data,
wherein the storage further stores second correction data for correcting light intensity distribution according to an irradiation position of the light, and
the signal processor performs second correction of eliminating an influence of the light intensity distribution for the measurement data based on the second correction data before the first correction.

2. The imaging system according to claim 1 ,
wherein the storage stores a plurality of pieces of the first correction data corresponding to divided regions of a plate on which the subject is placed, and
the signal processor performs the first correction for each piece of the measurement data obtained in each divided region.

3. The imaging system according to claim 1 , further comprising the light shielding plate.

4. The imaging system according to claim 3 ,
wherein the light shielding plate has a plurality of openings.

5. The imaging system according to claim 1 ,
wherein the light source unit includes:
a light source that emits the light sideways with respect to a direction of the detection surface;
a reflective diffusion plate that reflects and diffuses the light emitted from the light source toward the sensor unit; and
a transmissive diffusion plate disposed between the reflective diffusion plate and the sensor unit.

6. The imaging system according to claim 1 ,
wherein the light source unit includes:
a light source that emits the light toward the detection surface; and
a transmissive diffusion plate provided between the light source and the sensor.

7. The imaging system according to claim 1 ,
wherein the signal processor calculates an optical density of the subject based on measurement data for which the first correction has been performed.

8. The imaging system according to claim 1 ,
wherein the light source unit emits three or more kinds of the light having different wavelengths, and
the signal processing unit generates color data or a color image of the subject by combining measurement data obtained using the respective light beams.

9. An imaging system that images a subject by irradiating the subject with light and detecting light transmitted through the subject, comprising:
a light source unit;
a sensor that detects light emitted from the light source unit;
a storage that stores first correction data calculated based on a difference between first reference data and second reference data, the first reference data being detected by emitting the light with a light shielding plate having an opening placed between the light source unit and the sensor unit and being detected in an opening corresponding region, which is a region in a detection surface of the sensor unit corresponding to the opening of the shielding plate, the second reference data being detected in the opening corresponding region by emitting the light without placing the light shielding plate; and
a signal processor programmed to perform first correction of eliminating an influence of ambient light for measurement data, which is obtained by measurement using the subject, based on the first correction data,

wherein the light source unit includes,
a light source that emits the light toward the detection surface; and
a transmissive diffusion plate provided between the light source and the sensor,

wherein the light source is an ultraviolet light source, and
wherein the light source unit includes a conversion plate that converts ultraviolet light into visible light, the conversion plate being provided between the light source and the transmissive diffusion plate.

10. An imaging method for imaging a subject by irradiating the subject with light and detecting light transmitted through the subject, comprising:
performing first correction of eliminating an influence of ambient light for measurement data, which is obtained by measurement using the subject, based on first correction data calculated based on a difference between first reference data and second reference data, the first reference data being detected by emitting the light from a light source unit with a light shielding plate having an opening placed between a light source unit and a sensor unit and being detected in an opening corresponding region, which is a region in a detection surface of the sensor unit corresponding to the opening of the shielding plate, the second reference data being detected in the opening corresponding region by emitting the light from the light source unit without placing the light shielding plate,
wherein second correction of eliminating an influence of light intensity distribution is performed for the measurement data based on second correction data for correcting the light intensity distribution according to an irradiation position of the light, and
the first correction is performed for the measurement data for which the second correction has been performed.

11. The imaging method according to claim 10 , further comprising calculating the first correction data.

12. The imaging method according to claim 11 ,
wherein a plurality of pieces of the first correction data are calculated corresponding to divided regions of a plate on which the subject is placed, and
the first correction is performed for each piece of the measurement data obtained in each divided region.

13. The imaging method according to claim 11 ,
wherein, when acquiring the first and second reference data, a semi-light shielding plate having a known optical density is disposed at a position corresponding to the opening corresponding region.

Assignees

• Fujifilm Corp

Inventors

• Tanaka Yasutake
• Yamaguchi Akira

Classifications

• H04N1/407 Primary

  Control or modification of tonal gradation or of extreme levels, e.g. background level · CPC title

• H04N23/74

  by influencing the scene brightness using illuminating means · CPC title

• H04N1/00997

  Light control, e.g. shielding from ambient light or preventing light leakage · CPC title

• H04N5/23229 Primary

  Electricity · mapped topic

• H04N5/2354

  Electricity · mapped topic