U.S. patent application number 16/530880 was filed with the patent office on 2020-07-02 for clamping circadian lighting apparatus.
The applicant listed for this patent is Aleddra Inc.. Invention is credited to Chia-Yiu Maa, Chun-Te Yu.
Application Number | 20200206527 16/530880 |
Document ID | / |
Family ID | 71123614 |
Filed Date | 2020-07-02 |
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United States Patent
Application |
20200206527 |
Kind Code |
A1 |
Maa; Chia-Yiu ; et
al. |
July 2, 2020 |
Clamping Circadian Lighting Apparatus
Abstract
A circadian lighting apparatus includes a housing, two light
sources, and a control logic. The first light source has a higher
color temperature (e.g. 5000K) and the second light source has a
lower color temperature (e.g., 1900K). The control logic can clamp
operation color temperature to a mixed high color temperature
(e.g., 4000K) and a mixed low color temperature (e.g., 2700K), and
operate the apparatus according to a circadian schedule such that
the mixed high color temperature is used for a daytime circadian
state and the mixed low color temperature is used for a nighttime
circadian state, and the color temperature of the apparatus is
bound by the mixed high color temperature and the mixed low color
temperature. This apparatus enables a personalize-able circadian
light where each user can set his/her own circadian color
temperature range.
Inventors: |
Maa; Chia-Yiu; (Bellevue,
WA) ; Yu; Chun-Te; (Bellevue, WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Aleddra Inc. |
Renton |
WA |
US |
|
|
Family ID: |
71123614 |
Appl. No.: |
16/530880 |
Filed: |
August 2, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
16235058 |
Dec 28, 2018 |
10609798 |
|
|
16530880 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 21/02 20130101;
A61N 5/0618 20130101; A61M 21/00 20130101; A61M 2021/0044 20130101;
A61M 2205/502 20130101; H05B 47/105 20200101; A61N 2005/0663
20130101 |
International
Class: |
A61N 5/06 20060101
A61N005/06; A61M 21/02 20060101 A61M021/02; H05B 37/02 20060101
H05B037/02 |
Claims
1. A circadian lighting apparatus, comprising: a housing; at least
two light sources comprising a first light source and a second
light source; and a control logic, wherein: the first light source
has a first color temperature, the second light source has a second
color temperature lower than the first color temperature, the
control logic is configured to set a maximum operating color
temperature, CT.sub.max, to be lower than the first color
temperature of the first light source, wherein CT.sub.max is
achieved by mixing color temperatures of the first and the second
light sources, the control logic is also configured to set a
minimum operating color temperature, CT.sub.min, to be higher than
the second color temperature of the second light source, wherein
CT.sub.min, is achieved by mixing the color temperatures of the
first and the second light sources, and during operation in a
circadian schedule, the control logic is configured to restrict a
color temperature of the apparatus to be higher than CT.sub.min and
lower than CT.sub.max throughout the circadian schedule.
2. The circadian lighting apparatus of claim 1, wherein the total
light output of the apparatus is a linear combination of a first
light output of the first light source and a second light output of
the second light source in terms of power consumptions of first
light source and the second light source.
3. The circadian lighting apparatus of claim 2, wherein a maximum
power consumption of first light source equals to a maximum power
consumption of the second light source.
4. The circadian lighting apparatus of claim 3, wherein the control
logic operates the circadian state transition according to the
circadian schedule through a smooth and continuous color-tuning
between CT.sub.min and CT.sub.max by adjusting the power
consumptions of the first light source and the second light
source.
5. The circadian lighting apparatus of claim 4, wherein the smooth
and continuous color-tuning by the circadian state transition
according to the circadian schedule is approximated by a discrete
color-tuning with a fixed number of linear combinations of the
first and the second light sources.
6. (canceled)
7. A method for operating at least two light sources each with a
distinct color temperature, comprising: setting a maximum operating
color temperature, CT.sub.max, to be lower than a first color
temperature of a first light source of the at least two light
sources, wherein CT.sub.max is achieved by mixing color
temperatures of the first and the second light sources; setting a
minimum operating color temperature, CT.sub.min, to be higher than
a second color temperature of a second light source of the at least
two light sources, wherein CT.sub.min, is achieved by mixing the
color temperatures of the first and the second light sources; and
restricting, during operation in a circadian schedule, a resultant
color temperature to be higher than CT.sub.min and lower than
CT.sub.max throughout the circadian schedule.
Description
CROSS REFERENCE TO RELATED PATENT APPLICATION
[0001] The present disclosure is a Continuation-in-Part (CIP) of
U.S. patent application Ser. No. 16/235,058, filed on Dec. 28,
2018, the content of which is herein incorporated by reference in
its entirety.
BACKGROUND
Technical Field
[0002] The present disclosure pertains to the field of lighting
devices and, more specifically, proposes a circadian lighting
apparatus.
Description of Related Art
[0003] It is well known that circadian rhythm affects the behavior
of animals, including human. Studies have also shown circadian
lighting which is a lighting device based on a circadian rhythm
could improve the recovery of patients in hospital. A circadian
lighting works this way: a blue-enriched light stimulates the
awareness and the alert level of the human body, thus suitable for
working hours; a blue-depleted light clams down the human body to a
lower alert level, thus suitable for off-work hours. Moreover, it
is identified that human's circadian response curve over light
spectrum differs than human's visual response curve. The
blue-enriched light may be implemented by using a light source with
a high color temperature, e.g., 5000K. The blue-depleted light may
be implemented by using a light source with a low color
temperature, e.g., 1900K.
[0004] FIG. 1 shows the spectral power distribution (SPD) of
typical 1900K and 5000K LED light sources. As it can be seen from
the SPD curves, the 5000K LED light sources indeed provides strong
blue light SPD and the 1900K LED light sources is rather
blue-depleted. It is not uncommon to use the combination of 1900K
and 5000K LED light sources for making circadian lighting
apparatus. However, the use of 1900K LED light source introduces
another question. While its light is blue-depleted, the 1900K LED
light source generates an amber color light. Not only the amber
color light has a color temperature much lower than the warm white
color at 2700K, which is the most popular color temperature for
residential lighting application, but also the amber color is not a
suitable color for use as a reading light. Existing implementations
of circadian light leave users no choice but to accept an amber
light for nighttime with poor reading light quality. A better
solution is to devise a circadian lighting apparatus that allows a
user to set his/her own circadian color temperature range, such
that for people that is less sensitive to blue-induced sleep
problem can set his/her nighttime circadian color temperature
higher to 2700K (rather than 1900K) for a more comfortable reading
light color. The same can be said for the high circadian color
temperature. While some people prefer 5000K, others may want a
lower color temperature at 4000K or even 3500K. Such needs are not
properly addressed by the existing circadian lighting systems.
SUMMARY
[0005] The present disclosure introduces a clamping circadian
lighting apparatus that allows a user to set his/her own circadian
light color temperature range.
[0006] In one aspect, the present disclosure comprises a housing,
two light sources, and a control logic. The first light source may
have a higher color temperature such as 5000K, and the second light
source may have a lower color temperature such as 1900K. The
control logic has a means to mix the color temperature of the first
and the second light sources to produce a mixed high color
temperature (e.g., 4000K). The control logic also has a means to
mix the color temperature of the first and the second light sources
to produce a mixed low color temperature (e.g. 2700K). The control
logic may operate according to a circadian schedule to transition
the light output of the present disclosure from the mixed high
color temperature at a daytime circadian state to the mixed low
color temperature at a nighttime circadian state, and back and
forth. The daytime circadian state is not restricted to daytime
hours. For example, for night shift workers, their daytime
circadian state would align to their working hours, 9 pm to 5 am,
in order to keep their biological system on a highly active state
during the working hours.
[0007] In some embodiments, the total light output of the present
disclosure may be a linear combination of the light output of the
first and the second light sources, in terms of the power
consumption of first light source and the second light source. In
other words, given a fixed overall wattage consumption W, the power
consumption of the present disclosure is represented as the
following formula:
W=Y*W1+(1-Y)*W2
[0008] Where Yin [0%, 100%] represents the power consumption
percentage of the first light source, (1-Y) represents the power
consumption percentage of the second light source, and W1 and W2
represent the maximum wattages of the first and the second light
sources, respectively. In some embodiments, W1 equals to W2, that
is, the maximum power consumption of first light source equals to
the maximum power consumption of the second light source.
[0009] In some embodiments, where W1 equals to W2 (both equal to
W), the control logic of the present disclosure operates the
circadian state transition according to a circadian schedule
through a smooth (continuous) color-tuning between the mixed high
color temperature and the mixed low color temperature by adjusting
the power consumptions of first light source and the second light
source. For example, the mixed high color temperature may be
achieved at
Y1*W+(1-Y1)*W at a fixed percentage Y1,
and the mixed low color temperature may be achieved at
Y2*W+(1-Y2)*W at a fixed percentage Y2,
Then circadian state transition of the present disclosure can be
represented as
Y3*(Y1*W+(1-Y1)*W)+(1-Y3)*(Y2*W+(1-Y2)*W)=(Y3*Y1+(1-Y3)*Y2)*W+((Y3*(1-Y1-
))+(1-Y3)*(1-Y2)))*W,
where,
[0010] (Y3*Y1+(1-Y3)*Y2)*W represents the power consumption of the
first light source, and
[0011] ((Y3*(1-Y1))+(1-Y3)*(1-Y2)))*W represents the power
consumption of the second light source, and that
(Y3*Y1+(1-Y3)*Y2)+((Y3*(1-Y1))+(1-Y3)*(1-Y2)))=1.
[0012] The continuous color-tuning mentioned above may require a
rather complicate design of the control logic. In some cases, a
simplified control logic that approximate the continuously
color-tuning of the apparatus may suffice. Therefore, in some
embodiments, the smooth (continuous) circadian state transition
according to a circadian schedule is approximated by a discrete
color-tuning with a fixed number of linear combinations of the
first and the second light sources.
[0013] Giving the end user a means for setting the mixed high color
temperature and the mixed low color provides a great flexibility.
However, for an average user, it would be difficult for the user to
know which the right color temperature is. A better approach may be
to offer the end the most popular choices. For example, for the
mixed low color temperature, rather than offer any color
temperature between 1900K and 3000K, it may be better to offer only
four choices: 1900K (blue depleted), 2200K (low blue), 2700K
(standard warm white), and 3000K (daylight warm white). Similarly,
it suffices to offer four choices (3500K, 4000K, 4500K, and 5000K)
for selecting the mixed high color temperature. Therefore, in some
embodiments, the control logic of the present disclosure provides a
set of mixed color temperatures of the first light source and the
second light source to be selected from for setting the mixed high
color temperature, and also provides a set of combined color
temperatures of the first light source and the second light source
to be selected from for setting the mixed low color
temperature.
[0014] In another aspect, the present disclosure introduces a
method operating at least two light sources each with a distinct
color temperature. This method comprises setting a mixed high color
temperature by mixing the color temperature of the at least two
light sources, setting a mixed low color temperature by mixing the
color temperature of the at least two light sources, and operating
at least two light sources according to a circadian schedule. The
combined color temperature range of the at least two light sources
is bound by the mixed low color temperature and the mixed high
color temperature.
RIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings are included to aid further
understanding of the present disclosure and are incorporated in and
constitute a part of the present disclosure. The drawings
illustrate a select number of embodiments of the present disclosure
and, together with the detailed description below, serve to explain
the principles of the present disclosure. It is appreciable that
the drawings are not necessarily to scale, as some components may
be shown to be out of proportion to size in actual implementation
in order to clearly illustrate the concept of the present
disclosure.
[0016] FIG. 1 shows the spectral power distribution of 1900K and
5000K LED light sources.
[0017] FIG. 2 schematically depicts the exterior diagram of a
circadian lighting apparatus.
[0018] FIG. 3 schematically depicts an interior diagram of a
circadian lighting apparatus using high color temperature LEDs and
low color temperature LEDs.
[0019] FIG. 4 shows a table with the power consumption ratios for
1900K and 5000K LED for achieving different mixed color
temperatures.
[0020] FIG. 5 shows a discrete circadian schedule table with the
power consumption ratios for 1900K and 5000K LED's, given the mixed
low color temperature at 2700K and the mixed high color temperature
at 5000K.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Overview
[0021] Various implementations of the present disclosure and
related inventive concepts are described below. It should be
acknowledged, however, that the present disclosure is not limited
to any particular manner of implementation, and that the various
embodiments discussed explicitly herein are primarily for purposes
of illustration. For example, the various concepts discussed herein
may be suitably implemented in a variety of lighting apparatuses
having different form factors.
Example Implementations
[0022] The FIG. 2 is a circadian lighting apparatus 100 of the
present disclosure in the form of an overbed lighting fixture. This
apparatus has an up light 101 and a down light (not shown). The
FIG. 3 shows the PCB boards of the up light and the down light. On
the up light PCB board 201, there are two rows of LEDs, the
blue-enriched LEDs 202 and the blue depleted LEDs 203. Similarly,
on the down light PCB board 204, there are two rows of LEDS, the
blue-enriched LEDs 205 and the blue depleted LED 206. All
blue-enriched LEDs 202, 205 have a color temperature 5000K. All
blue-depleted LEDs 203, 206 have a color temperature 1900K. For the
up light or the down light, the total power consumption of its
5000K LED's equals the total power consumption of its 1900K
LED's.
[0023] This example implementation uses a set of mixed low color
temperatures, 1900K, 2200K, 2700K, and 3000K, and another set of
mixed high color temperature, 3500K, 4000K, 4500K, and 5000K. The
FIG. 4 shows a hypothetical model on the mixing of 1900K and 5000K
LED's for achieving different mixed color temperatures.
[0024] This example implementation also uses a discrete circadian
schedule as shown in the first column of the table in FIG. 5. Each
user may select a different mixed low color temperature and a
different mixed high color temperature. The table shows the case
when the mixed low temperature is 2700K and the mixed high
temperature is 5000K. The total power consumption ratios of 1900K
and 5000K LED's according to the discrete circadian schedule are
calculated and shown in the last two columns of the table in FIG.
5. For example, during 7:00-7:30 am, the total power consumption
ratio of 1900K LED is 63% and the total power consumption ratio of
5000K LED is 37%.
[0025] In some implementations, there may be more discrete
circadian states, and even a continuous circadian state transition.
The circadian schedule may be static or dynamically adjustable, for
example, according to the season so there is a longer daytime
circadian schedule in summer.
Additional and Alternative Implementation Notes
[0026] Although the techniques have been described in language
specific to certain applications, it is to be understood that the
appended claims are not necessarily limited to the specific
features or applications described herein. Rather, the specific
features and examples are disclosed as non-limiting exemplary forms
of implementing such techniques.
[0027] As used in this application, the term "or" is intended to
mean an inclusive "or" rather than an exclusive "or." That is,
unless specified otherwise or clear from context, "X employs A or
B" is intended to mean any of the natural inclusive permutations.
That is, if X employs A; X employs B; or X employs both A and B,
then "X employs A or B" is satisfied under any of the foregoing
instances. In addition, the articles "a" and "an" as used in this
application and the appended claims should generally be construed
to mean "one or more," unless specified otherwise or clear from
context to be directed to a singular form.
* * * * *