Methods and devices for adjusting brightness of a light source

• US 9,692,954 B2
• Filed: 03/28/2013
• Issued: 06/27/2017
• Est. Priority Date: 03/28/2013
• Status: Active Grant

• Current Assignee: Mant Manthey, Diane
• Original Assignee: General Electric Company
• Inventors: Delmonico, James J., Mcenery, Dennis William
• Primary Examiner(s): Vo, Tung
• Assistant Examiner(s): Jiang, Zaihan
• Application Number:
  US13/852,549
• Publication Number:
  US 20140293038A1
• Time in Patent Office: 1,552 Days
• Field of Search: 348 82, 315291, 315302
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H05B 45/28 using temperature feedback
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]

Abstract

Various exemplary devices and methods are provided for adjusting brightness of a light source. In general, the devices and methods can allow brightness of a light source to be adjusted by varying a power supply of the light source. The power supply can be varied in response to a user input. In one exemplary embodiment, the light source can be included as part of a scope, e.g., a borescope, an endoscope, etc., configured to be advanced into a target and to gather one or more video images and/or one or more still images within the target using a camera. The light source can be configured to illuminate the target at a selected one of the variable amounts of brightness. A white balance of the light source can be configured to automatically adjust in response to the selected amount of brightness.

Claims

1. A device, comprising:

a light source comprising a variable brightness that ranges between a first brightness and a second brightness, the second brightness being greater than the first brightness;

a camera, the camera and the light source being configured to be advanced into a target, the light source being configured to illuminate one or more internal components of the target, and the camera being configured to gather one or more images of the illuminated one or more internal components; and

a control circuit configured to adjust the brightness of the light source without using on/off cycling of the light source, the control circuit comprising;

at least one switchable gain block coupled to the light source, the at least one switchable gain block being selectively switchable between a first current gain and a second current gain, the first and second current gains being different current gains, wherein the control circuit is adapted for switching the switchable gain block to the first current gain responsive to a light source brightness control element changing the brightness of the light source in a first range of brightness of the light source that extends between the first brightness to a first intermediate brightness that is between the first and second brightnesses, and to the second current gain responsive to the light source brightness control element changing the brightness of the light source in a second range of brightness of the light source that extends between a second intermediate brightness and the second brightness, the second intermediate brightness being less than the first intermediate brightness;

wherein the first and second ranges have an overlap range of brightness, the overlap range of brightness extending from the second intermediate brightness to the first intermediate brightness and facilitating a transition of the brightness of the light source between the first range and the second range; and

wherein the control circuit is adapted for controlling the switchable gain block using in part a predetermined illumination performance function, the controlling comprising;

receiving first input signals from the light source and second input signals from the brightness control element;

determining, from the first and second input signals and the predetermined illumination performance function, a brightness transition between a first range of brightness of the light source and a second range of brightness of the light source;

switching the switchable gain block from the first current gain to the second current gain responsive to the brightness transition being from less than the overlap range of brightness into the overlap range of brightness; and

switching the switchable gain block from the second current gain to the first current gain responsive to the brightness transition being from greater than the overlap range of brightness into the overlap range of brightness; and

a processing module, the processing module being adapted for correcting the gathered one or more images of the illuminated one or more internal components for a shift in a color temperature of the light source due to the adjustment of the brightness without using on/off cycling of the light source.

2. The device of claim 1, wherein the switching is configured to occur in response to an input from a user indicating a desired level of the brightness.

3. The device of claim 2, further comprising a controller configured to receive the input and to cause the control circuit to switch between the first and second current gains in response to the input.

4. The device of claim 1, wherein the control circuit includes at least one of a potentiometer and an adjustable voltage reference digital-to-analog converter (DAC);

and

wherein the at least one of the potentiometer and the adjustable voltage reference DAC are configured to be adjusted to cause the switch between the first and second current gains.

5. The device of claim 1, wherein the control circuit is configured to switch between the first current gain and the second current gain when a current of the control circuit passes a predetermined threshold current.

6. The device of claim 5, wherein when the current gain is at the first current gain, the predetermined threshold current is a first current corresponding to the second intermediate brightness such that control circuit is configured to switch from the first current gain to the second current gain when the current of the control circuit moves above the first current;

and

when the current gain is at the second current gain, the predetermined threshold current is a second current corresponding to the first intermediate brightness such that control circuit is configured to switch from the second current gain to the first current gain when the current of the control circuit moves below the second current.

7. The device of claim 1, wherein the light source has a white balance that is adjustable based at least on the color temperature of the light source and the brightness of the light source.

8. The device of claim 1, wherein the control circuit is configured to switch between the first current gain, the second current gain, and a third current gain, the third current gain corresponding to a third range of brightness of the light source that extends between a third brightness that is less than the first brightness and a third intermediate brightness that is between the third brightness and the first intermediate brightness.

9. The device of claim 8, wherein the third intermediate brightness is greater than the first brightness.

10. The device of claim 8, wherein:

when the current gain is at the first current gain, the control circuit is configured to switch from the first current gain to the second current gain when the brightness moves above the second intermediate brightness in response to a user input;

when the current gain is at the first current gain, the control circuit is configured to switch from the first current gain to the third current gain when the brightness moves below the third intermediate brightness in response to a user input;

when the current gain is at the second current gain, the control circuit is configured to switch from the second current gain to the first current gain when the brightness moves below the first intermediate brightness in response to a user input; and

when the current gain is at the third current gain, the control circuit is configured to switch from the third current gain to the first current gain when the brightness moves above the first brightness in response to a user input.

11. A device, comprising:

a light source configured to emit light at a variably adjustable brightness that ranges between a first brightness and a second brightness without using on/off cycling of the light source, wherein the second brightness is greater than the first brightness;

a camera, the camera and the light source being configured to be advanced into a target, the light source being configured to illuminate one or more internal components of the target, and the camera being configured to gather one or more images of the illuminated one or more internal components;

a light source brightness control element configured to receive an input from a user indicating a desired level of the brightness;

a control circuit configured to adjust the brightness of the light source, the control circuit comprising;

at least one switchable gain block coupled to the light source, the at least one switchable gain block being selectively switchable between a first current gain and a second current gain, the first and second current gains being different current gains, wherein the control circuit is adapted for switching the switchable gain block to the first current gain responsive to the light source brightness control element changing the brightness of the light source in a first range of brightness of the light source that extends between the first brightness to a first intermediate brightness that is between the first and second brightnesses, and to the second current gain responsive to the light source brightness control element changing the brightness of the light source in second range of brightness of the light source that extends between a second intermediate brightness and the second brightness and a second intermediate brightness, the second intermediate brightness being less than the first intermediate brightness, wherein the first and second ranges have an overlap range of brightness, the overlap range of brightness extending from the second intermediate brightness to the first intermediate brightness and facilitating a transition of the brightness of the light source between the first range and the second range; and

a controller configured to;

adjust the brightness by controlling the switchable gain block using in part a predetermined illumination performance function, the controlling comprising;

receiving first input signals from the light source and second input signals from the brightness control element;

determining, from the first and second input signals and the predetermined illumination performance function, a brightness transition between a first range of brightness of the light source and a second range of brightness of the light source;

switching the switchable gain block from the first current gain to the second current gain responsive to the brightness transition being from less than the overlap range of brightness into the overlap range of brightness;

switching the switchable gain block from the second current gain to the first current gain responsive to the brightness transition being from greater than the overlap range of brightness into the overlap range of brightness; and

correcting the gathered one or more images of the illuminated one or more internal components for a shift in a color temperature of the light source due to the adjustment of the brightness without using on/off cycling of the light source.

12. The device of claim 11, wherein the controller is configured to adjust the brightness when the light source is emitting light such that the user can visually perceive the brightness adjustment.

13. The device of claim 11, wherein a dynamic range of the brightness is at least 600:

1.

14. The device of claim 11, wherein the controller is configured to adjust the brightness by selecting, in response to the input, one of the first feedback gain, the second feedback gain, and at least one additional feedback gain to supply power to the light source.

15. The device of claim 14, wherein a dynamic range of the brightness is at least 10000:

1.

16. The device of claim 11, wherein the light source is configured to be advanced into any one of a turbine, so as to illuminate one or more internal parts of the turbine at the brightness, and a body of a patient, so as to illuminate one or more internal areas of the patient at the brightness.

17. A method comprising:

adjusting the brightness of a light source without using on/off cycling of the light source, the light source having a variable brightness that ranges between a first brightness and a second brightness, the second brightness being greater than the first brightness, the adjusting the brightness of the light source comprising;

receiving a user input regarding a device advanced into a target and illuminating with a light source one or more internal components of the target, the user input indicating a desired level of brightness of the light source; and

adjusting, in response to the user input, a power supply of the light source by changing a current of the power supply such that the brightness of the light source is adjusted, the adjusting the power supply comprising;

switching a switchable gain block coupled to the light source from a first current gain to a second current gain that is greater than the first current gain when the current is adjusted to exceed a first predetermined threshold current, and from the second current gain to the first current gain when the current is adjusted to be less than a second predetermined threshold current that is greater than the first predetermined threshold current, wherein switching to the first current gain is responsive to a light source brightness control element changing the brightness of the light source in a first range of brightness of the light source that extends between the first brightness to a first intermediate brightness that is between the first and second brightnesses, and switching to the second current gain is responsive to the light source brightness control element changing the brightness of the light source in a second range of brightness of the light source that extends between a second intermediate brightness and the second brightness and a second intermediate brightness, the second intermediate brightness being less than the first intermediate brightness;

wherein the first and second ranges have an overlap range of brightness, the overlap range of brightness extending from the second intermediate brightness to the first intermediate brightness and facilitating a transition of the brightness of the light source between the first range and the second range; and

controlling the switchable gain block using in part a predetermined illumination performance function, the controlling comprising;

receiving first input signals from the light source and second input signals from the brightness control element;

determining, from the first and second input signals and the a predetermined illumination performance function, a brightness transition between a first range of brightness of the light source and a second range of brightness of the light source;

switching the switchable gain block from the first current gain to the second current gain responsive to the brightness transition being from less than the overlap range of brightness into the overlap range of brightness; and

switching the switchable gain block from the second current gain to the first current gain responsive to the brightness transition being from greater than the overlap range of brightness into the overlap range of brightness;

advancing the light source and a camera into a target, the light source being configured to illuminate one or more internal components of the target, and the camera being configured to gather one or more images of the illuminated one or more internal components; and

correcting the gathered one or more images of the illuminated one or more internal components for a shift in a color temperature of the light source due to the adjustment of the brightness without using on/off cycling of the light source.

18. The method of claim 17, further comprising, when the current is adjusted to be less than a third predetermined threshold that is less than the first predetermined threshold current, changing from the first current gain to a third current gain that is less than the first current gain.

19. The method of claim 17, further comprising adjusting, in response to the user input, a white balance of the light source based at least on the current of the power supply and the color temperature of the light source.