LIGHT SOURCE APPARATUS AND LIGHT-ADJUSTING METHOD FOR LIGHT SOURCE APPARATUS

• US 20140192551A1
• Filed: 01/15/2014
• Published: 07/10/2014
• Est. Priority Date: 09/18/2012
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Medical Systems Corporation (Olympus Corporation)
• Inventors: MASAKI, Takahiro
• Granted Patent: US 8,979,341 B2
• Time in Patent Office: Days
• US Class Current: 362/574
• CPC Class Codes: A61B 1/00006 of control signals
• CPC Class Codes: A61B 1/0638 providing two or more wavelengths
• CPC Class Codes: A61B 1/0646 with illumination filters
• CPC Class Codes: A61B 1/0655 Control therefor
• CPC Class Codes: A61B 1/0661 Endoscope light sources
• CPC Class Codes: A61B 1/0669 at proximal end of an endoscope
• CPC Class Codes: G02B 23/2469 using optical fibres

Abstract

A light source apparatus includes: a lamp, a diaphragm device, a CPU that causes the diaphragm device to execute adjustment of an emission amount of illumination light on the basis of a target brightness signal generated based on brightness of an image obtained by picking up an image of a subject; a CPU that switches between illumination modes, and a mode switching switch. During a period after an instruction for switching from one of an illumination mode corresponding to normal light observation mode and an illumination mode corresponding to special light observation mode to the other is given until the switching by the CPU is completed, the CPU causes the diaphragm device to execute adjustment of the emission amount of the illumination light based on a correction value obtained by correcting a current diaphragm value at the time when the instruction for switching is given using a predetermined coefficient.

Claims

1. A light source apparatus comprising:

a light source for supplying illumination light to a subject;

an illumination light amount adjusting section capable of adjusting an emission amount of the illumination light;

an illumination light amount control section that causes the illumination light amount adjusting section to execute adjustment of the emission amount of the illumination light on the basis of a light amount control signal generated based on brightness of an image obtained by picking up an image of the subject;

an illumination mode switching control section that switches between a first illumination mode in which first light is emitted as the illumination light and a second illumination mode in which second light is emitted as the illumination light, the second light having a wavelength band, at least a part of the wavelength band being different from a wavelength band of the first light; and

a switching instruction section that gives an instruction for switching between the first illumination mode and the second illumination mode,

wherein, during a period after an instruction for switching from one of the first illumination mode and the second illumination mode to the other of the first and second illumination modes is given by the switching instruction section until the switching by the illumination mode switching control section is completed, the illumination light amount control section maintains the light amount control signal at a predetermined value corresponding to the illumination mode after the completion of the mode switching, and causes the illumination light amount adjusting section to execute adjustment of the emission amount of the illumination light on the basis of the maintained value.

2. The light source apparatus according to claim 1, wherein the illumination light amount control section maintains, as the predetermined value, a value of a correction signal obtained by correcting the light amount control signal at a time when the instruction for the switching is given, using a predetermined coefficient corresponding to the illumination mode after the completion of the mode switching, and causes the illumination light amount adjusting section to execute adjustment of emission amount of the illumination light on the basis of the maintained value.

3. The light source apparatus according to claim 1, wherein

the illumination light amount control section includes a control calculation section that receives the light amount control signal, to calculate an adjustment value of the emission amount of the illumination light and output the calculated adjustment value, and

when the switching is completed, the illumination mode switching control section inputs a predetermined signal to the control calculation section and thereafter inputs the light amount control signal to the control calculation section.

4. The light source apparatus according to claim 1, wherein, when a value of the correction signal exceeds a predetermined upper limit value or falls below a predetermined lower limit value, the illumination mode switching control section changes the value of the correction signal to the predetermined upper limit value or the predetermined lower limit value.

5. The light source apparatus according to claim 1, wherein

the light source includes a lamp that emits light, and an optical filter provided so as to be insertable into and removable from an optical path of the light emitted from the lamp, the optical filter being configured to transmit light having a wavelength band which is a part of wavelength band of the emitted light in a state where the optical filter is inserted into the optical path,

the first illumination mode is a mode in which the optical filter is inserted into the optical path and the light transmitted by the optical filter is used as the illumination light,

the illumination light amount adjusting section includes a diaphragm device that adjusts a light amount of the illumination light, and a diaphragm driving section that drives the diaphragm device according to a diaphragm driving control signal inputted thereto, and

the illumination light amount control section generates the diaphragm driving control signal on the basis of the light amount control signal.

6. The light source apparatus according to claim 1, wherein the first illumination mode and the second illumination mode are illumination modes corresponding to observation modes in an endoscope apparatus.

7. The light source apparatus according to claim 6, wherein the first illumination mode and the second illumination mode are a special light observation mode and a normal light observation mode in the endoscope apparatus, respectively.

8. A light-adjusting method for a light source apparatus, comprising:

executing adjustment of an emission amount of illumination light of the light source apparatus on the basis of a light amount control signal generated based on brightness of a subject by an illumination light amount adjusting section of the light source apparatus; and

during a period after an instruction for switching from one of a first illumination mode in which first light is emitted as the illumination light and a second illumination mode in which second light having a wavelength band, at least a part of which is different from a wavelength band of the first light, is emitted as the illumination light to the other of the first and second illumination modes is given until the switching is completed, maintaining the light amount control signal at a predetermined value corresponding to the illumination mode after the completion of the mode switching, and executing adjustment of the emission amount of the illumination light on the basis of the maintained value by the illumination light amount adjusting section.

9. The light-adjusting method for the light source apparatus according to claim 8, wherein the illumination light amount control section maintains, as the predetermined value, a value of a correction signal obtained by correcting the light amount control signal at a time when the instruction for the switching is given, using a predetermined coefficient corresponding to the illumination mode after the completion of the mode switching and causes the illumination light amount adjusting section to execute adjustment of emission amount of the illumination light on the basis of the maintained value.

10. The light-adjusting method for the light source apparatus according to claim 8, wherein, when the switching is completed, a predetermined signal is inputted to the control calculation section which receives the light amount control signal, calculates an adjustment value of the emission amount of the illumination light, and outputs the calculated adjustment value, and thereafter the light amount control signal is inputted to the control calculation section.

11. The light-adjusting method for the light source apparatus according to claim 8, wherein when a value of the correction signal exceeds a predetermined upper limit value or falls below a predetermined lower limit value, the value of the correction signal is changed to the predetermined upper limit value or the predetermined lower limit value.

12. The light-adjusting method of light source apparatus according to claim 8, wherein

the light source apparatus includes a lamp that emits light, and an optical filter provided so as to be insertable into and removable from an optical path of the light emitted from the lamp, the optical filter being configured to transmit light having a wavelength band which is a part of wavelength band of the emitted light in a state where the optical filter is inserted into the optical path,

the first illumination mode is a mode in which the optical filter is inserted into the optical path and the light transmitted by the optical filter is used as the illumination light,

the illumination light amount adjusting section includes a diaphragm device that adjusts a light amount of the illumination light, and a diaphragm driving section that drives the diaphragm device according to a diaphragm driving control signal inputted thereto, and

the diaphragm driving control signal is generated on the basis of the light amount control signal.

13. The light-adjusting method of the light source apparatus according to claim 8, wherein the first illumination mode and the second illumination mode are illumination modes corresponding to observation modes in an endoscope apparatus.

14. The light-adjusting method for the light source apparatus according to claim 13, wherein the first illumination mode and the second illumination mode are a special light observation mode and a normal light observation mode in the endoscope apparatus, respectively.