Lighting device, image capturing system, and lighting control method

• US 9,280,036 B2
• Filed: 02/18/2014
• Issued: 03/08/2016
• Est. Priority Date: 10/31/2013
• Status: Expired due to Fees

• Current Assignee: PFU Limited (Fujitsu Limited)
• Original Assignee: PFU Limited (Fujitsu Limited)
• Inventors: Kasahara, Yuki, Li, Jian
• Primary Examiner(s): Laballe, Clayton E
• Assistant Examiner(s): Smith, Linda B
• Application Number:
  US14/183,185
• Publication Number:
  US 20150117849A1
• Time in Patent Office: 749 Days
• Field of Search: 396/164
• US Class Current: 1/1
• CPC Class Codes: G03B 15/02 Illuminating scene
• CPC Class Codes: G03B 15/03 Combinations of cameras with lighting apparatus; Flash units
• CPC Class Codes: G03B 15/05 Combinations of cameras with electronic flash apparatus; Electronic flash units
• CPC Class Codes: G03B 15/07 Arrangements of lamps in studios
• CPC Class Codes: G03B 17/561 Support related camera accessories

Abstract

A lighting device includes a base unit arranged on a medium installation face on which a medium is disposed, an arm unit extending upwardly from the base unit, a top unit extending from the arm unit so as to face the medium installation face, a mounting face disposed on the top unit to mount an image capturing unit at a position capable of photographing the medium on the medium installation face, a lighting disposed in the top unit to irradiate the medium installation face, and a lighting control unit configured to adjust an amount of light of the lighting. The lighting control unit sets the amount of light of the lighting to a maximum at the time of photographing and, after the photographing, returns the amount of light to that before the photographing.

Claims

1. A lighting device comprising:

a base unit arranged on a medium installation face on which a medium that is a reading target is disposed;

an arm unit extending upwardly from the base unit;

a top unit extending from the arm unit so as to face the medium installation face;

a mounting face disposed on the top unit to mount an image capturing unit at a position for photographing the medium disposed on the medium installation face, the image capturing unit including a first communication unit to perform wireless communication;

a lighting disposed in the top unit to irradiate the medium installation face;

a lighting control unit configured to perform driving control to adjust an amount of light of the lighting;

a second communication unit arranged in the lighting device, the second communication unit configured to perform wireless communication with the first communication unit, and

a scan switch disposed on the base unit, the scan switch generating a scan start trigger to be transmitted to the image capturing unit through the second communication unit and the first communication unit,

wherein the image capturing unit is configured to determine whether or not the lighting is in a turned-on state subsequent to receiving the scan start trigger, and when the lighting is determined to be in the turned-on state, the image capturing unit instructs the lighting control unit to set the amount of light of the lighting to a maximum at the time of photographing and, after the photographing, the image capturing unit instructs the lighting control unit to return the amount of light of the lighting to the amount of light before the photographing, and

when the lighting is determined to be in the turned-off state subsequent to receiving the scan start trigger, the image capturing unit perform photographing without turning on the lighting.

2. The lighting device according to claim 1,

wherein the driving control is pulse width modulation (PWM) control, and

wherein the lighting control unit sets a duty ratio of the PWM control to 100% at the time of the photographing.

3. An image capturing system comprising:

an image capturing unit configured to photograph a medium; and

a lighting device including

a base unit arranged on a medium installation face on which the medium that is a reading target is disposed,

an arm unit extending upwardly from the base unit,

a top unit extending from the arm unit so as to face the medium installation face,

a mounting face disposed on the top unit to mount the image capturing unit at a position for photographing the medium disposed on the medium installation face,

a lighting disposed in the top unit to irradiate the medium installation face,

a lighting control unit configured to perform driving control to adjust an amount of light of the lighting,

a second communication unit arranged in the lighting device, the second communication unit configured to perform wireless communication with the first communication unit, and

a scan switch disposed on the base unit, the scan switch generating a scan start trigger to be transmitted to the image capturing unit through the second communication unit and the first communication unit,

wherein the image capturing unit is configured to determine whether or not the lighting is in a turned-on state subsequent to receiving the scan start trigger, and when the lighting is determined to be in the turned-on state, the image capturing unit instructs the lighting control unit to set the amount of light of the lighting to a maximum at the time of photographing and, after the photographing, the image capturing unit instructs the lighting control unit to return the amount of light of the lighting to the amount of light before the photographing, and

when the lighting is determined to be in the turned-off state subsequent to receiving the scan start trigger, the image capturing unit perform photographing without turning on the lighting.

4. A method of controlling lighting of a lighting device including a base unit arranged on a medium installation face on which a medium that is a reading target is disposed, an arm unit extending upwardly from the base unit, a top unit extending from the arm unit so as to face the medium installation face, a mounting face disposed on the top unit to mount an image capturing unit at a position for photographing the medium disposed on the medium installation face, the image capturing unit including a first communication unit to perform wireless communication, a lighting disposed in the top unit to irradiate the medium installation face, and a second communication unit arranged in the lighting device, the second communication unit configured to perform wireless communication with the first communication unit, a scan switch generating a scan start trigger to be transmitted to the image capturing unit through the second communication unit and the first communication unit, the method comprising:

irradiating the medium installation face with an amount of light of the lighting;

receiving the scan target trigger;

determining whether or not the lighting is in a turned-on state at the image capturing unit subsequent to receiving the scan start trigger;

when it is determined that the lighting is in the turned-on state subsequent to receiving the scan start trigger, instructing from the image capturing unit to set the amount of light of the lighting to a maximum at the time of photographing; and

after the photographing, instructing from the image capturing unit to return the amount of light of the lighting to the amount of light before the photographing, and

when it is determined that the lighting is in turned-off state subsequent to receiving the scan start trigger, performing photographing without turning on the lighting.