CONTROLLING A PHOTO-BIOLOGICAL EFFECT WITH LIGHT

• US 20090281604A1
• Filed: 04/03/2007
• Published: 11/12/2009
• Est. Priority Date: 04/11/2006
• Status: Abandoned Application

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: De Boer, Dirk Kornelis Gerhardus, De Vaan, Adrianus Johannes Stephanus Maria, Schlangen, Lucas Josef Maria
• Application Number:
  US12/296,677
• Publication Number:
  US 20090281604A1
• Time in Patent Office: Days
• US Class Current: 607/88
• CPC Class Codes: A61M 2021/005 images, e.g. video
• CPC Class Codes: A61M 21/00 Other devices or methods to cause a change in the state of consciousness; Devices for producing or ending sleep by mechanical, optical, or acoustical means, e.g. for hypnosis
• CPC Class Codes: A61N 2005/0663 Coloured light
• CPC Class Codes: A61N 5/0618 Psychological treatment
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 47/115 by determining the presence or movement of objects or living beings
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A device for generating at least blue light comprises a control circuit (4) which receives a control signal (CS) defining a variation of a spectrum of the blue light to control a photo-biological effect of a vertebrate. Therefore, first blue light (BL1) is generated with a first predominant wavelength (PW1) having a first photo-biological effect, or second blue light (BL2) is generated with both a second predominant wavelength (PW2), being shorter than the first predominant wavelength, and a third predominant wavelength (PW3), being longer than the first predominant wavelength; the second blue light (BL2) has a second photo-biological effect different from the first photo-biological effect, while the first blue light (BL1) and the second blue light (BL2) have substantially identical colors and intensities.

Claims

1. A device for generating at least blue light and having a control circuit (4) for receiving a control signal (CS) defining a variation of a spectrum of the blue light to control a photo-biological effect of a vertebrate by generating first blue light (BL1) with a first predominant wavelength (PW1) having a first photo-biological effect, and/or second blue light (BL2) with both a second predominant wavelength (PW2), being shorter than the first predominant wavelength, and a third predominant wavelength (PW3), being longer than the first predominant wavelength, wherein the second blue light (BL2) has a second photo-biological effect smaller than the first photo-biological effect, while the first blue light (BL1) and the second blue light (BL2) have substantially identical colors and intensities.

2. A device as claimed in claim 1, wherein the first predominant wavelength (PW1) is selected in a range of 460 to 480 nm, the second predominant wavelength (PW2) is selected in a range of 430 to 450 nm, and the third predominant wavelength (PW3) is selected in a range of 480 to 500 nm.

3. A device as claimed in claim 1, further comprising a first light source (B1) for generating the first blue light (BL1), a second light source (B2) for generating blue light with the second predominant wavelength (PW2), and a third light source (B3) for generating blue light with the third predominant wavelength (PW3).

4. A device as claimed in claim 3, wherein the first light source (B1) comprises a first LED, the second light source (B2) comprises a second LED, and the third light source (B3) comprises a third LED, and the device further comprises a drive circuit (3) for generating a first current (I1) through the first LED, a second current (I2) through the second LED, and a third current (I3) through the third LED, and the control circuit (4) is constructed for controlling the driver (3) to generate the first current (I1), the second current (I2), and the third current (I3) to obtain light having a desired color, intensity, and a photo-biological effect.

5. A device as claimed in claim 3, wherein the first light source (B1) is a first type of phosphor, the second light source (B2) is a second type of phosphor, and the third light source (B3) is a third type of phosphor, and the device further comprises a drive circuit (30) for deflecting an electron beam (31) to either hit the first type of phosphor or both the second type of phosphor and the third type of phosphor.

6. A device as claimed in claim 1, wherein the control signal (CS) is a trigger signal obtained by a wired or wireless link.

7. A device as claimed in claim 1, further comprising a time generating circuit (5) for generating the control signal (CS) having a cyclical behaviour to control the photo-biological effect cyclically.

8. A device as claimed in claim 7, wherein the time generating circuit (5) is constructed for generating the control signal (CS) synchronized with the day/night cycle.

9. A device as claimed in claim 6, further comprising a light sensitive element (5) for generating the trigger signal (CS) in response to an amount of light impinging on the light sensitive element.

10. A display device comprising pixels, each comprising the first light source (B1), the second light source (B2) and the third light source (B3), as claimed in claim 3.

11. A display device as claimed in claim 10, wherein the pixels each further comprise a fourth light source (G) and a fifth light source (R) for enabling the pixels to emit white light.

12. A display device as claimed in claim 11, wherein the fourth light source (G) emits green light and the fifth light source (R) emits red light.

13. A display device as claimed in claim 11, wherein the first light source (B1) comprises a first LED, the second light source (B2) comprises a second LED, the third light source (B3) comprises a third LED, the fourth light source (G) comprises a fourth LED, and the fifth light source (R) comprises a fifth LED, and the display device further comprises a drive circuit (3), and the control circuit (4) is constructed for receiving the control signal (CS) and an image signal (IS) to control the driver (3) to generate a first current (I) through the first LED, a second current (I2) through the second LED, and a third current (I3) through the third LED, a fourth current (IG) through the fourth LED, and a fifth current (IR) through the fifth LED, to obtain light having a desired color and intensity in accordance with the image signal (IS), and a photo-biological effect.

14. A display device as claimed in claim 10, further comprising sensing means for generating the control signal depending on biofeedback from a user.

15. A display device as claimed in claim 14, wherein the sensing means comprises at least one out of:

a skin/rectal temperature sensor, eye blinking sensor, eye movement sensor, skin conductance sensor, or a user-activity detector.

16. A display device as claimed in claim 15, wherein the user-activity detector is constructed for sensing a number of keystrokes per minute, or the intensity of the mouse use.

17. A display device as claimed in claim 1, wherein the photo-biological effect is a melatonin suppression effect or an alertness level.

18. A backlight unit for a display device comprising the first light source (B1), the second light source (B2) and the third light source (B3), as claimed in claim 3.

19. A method of generating at least blue light in response to a control signal (CS) defining a variation of a spectrum of the blue light to control a photo-biological effect of a vertebrate by generating first blue light (BL1) with a first predominant wavelength (PW1) having a first melatonin suppression effect, or second blue light (BL2) with both a second predominant wavelength (PW2), being shorter than the first predominant wavelength, and a third predominant wavelength (PW3), being longer than the first predominant wavelength, wherein the second blue light (BL2) has a second melatonin suppression effect smaller than the first melatonin suppression effect, while the first blue light (BL1) and the second blue light (BL2) have substantially identical colors and intensities.