U.S. patent application number 14/024568 was filed with the patent office on 2014-05-22 for system for optimized plant growth.
This patent application is currently assigned to Sensity Systems Inc.. The applicant listed for this patent is Sensity Systems Inc.. Invention is credited to Dan Morgan, Steve Oster.
Application Number | 20140140056 14/024568 |
Document ID | / |
Family ID | 50231768 |
Filed Date | 2014-05-22 |
United States Patent
Application |
20140140056 |
Kind Code |
A1 |
Morgan; Dan ; et
al. |
May 22, 2014 |
SYSTEM FOR OPTIMIZED PLANT GROWTH
Abstract
A system for enabling controlled plant growth of plants in
containers includes linear tracks spaced apart from each other by
intervening supporting plates. Each track includes an array of blue
and red LEDs affixed to a heat sink which can slide along the track
to be positioned in a desired arrangement to the container beneath
it. A controller for the LEDs is positioned between every other
pair of tracks to control adjacent arrays of LEDs. The controller
controls the LEDs to provide light of desired intensity and
wavelength to the plants in the containers.
Inventors: |
Morgan; Dan; (San Jose,
CA) ; Oster; Steve; (Auburn, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sensity Systems Inc. |
Sunnyvale |
CA |
US |
|
|
Assignee: |
Sensity Systems Inc.
Sunnyvale
CA
|
Family ID: |
50231768 |
Appl. No.: |
14/024568 |
Filed: |
September 11, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61699970 |
Sep 12, 2012 |
|
|
|
Current U.S.
Class: |
362/231 ;
362/249.02 |
Current CPC
Class: |
A01G 7/045 20130101;
F21K 9/65 20160801; H05B 47/11 20200101; F21V 21/005 20130101; H05B
47/19 20200101; H05B 45/10 20200101 |
Class at
Publication: |
362/231 ;
362/249.02 |
International
Class: |
F21V 21/005 20060101
F21V021/005; F21V 29/00 20060101 F21V029/00; F21K 99/00 20060101
F21K099/00 |
Claims
1. Apparatus for providing controlled wavelength and intensity of
light for use in a process involving exposure of items to light,
the apparatus comprising: a first plurality of linear tracks spaced
apart, disposed in a parallel arrangement, and separated from each
other by plates; a first plurality of arrays of light-emitting
diodes (LEDs), each array being positioned in one of the tracks;
and at least one controller coupled to each of the first plurality
of arrays of LEDs; wherein the controller controls the LEDs to
provide controlled wavelength and intensity of light to the
items.
2. Apparatus as in claim 1 wherein each of the tracks is of a same
size and shape, and each of the plates is of a same size and shape
to enable enlarging the apparatus by adding additional tracks and
additional plates to provide a desired size.
3. Apparatus as in claim 1 wherein the at least one controller
comprises a second plurality of controllers, the second plurality
being one half the first plurality.
4. Apparatus as in claim 3 wherein a controller is disposed on
every other plate and coupled to an array of LEDs in tracks on each
side of the controller.
5. Apparatus as in claim 1 further comprising a light sensor
positioned in proximity to the items and coupled to at least some
of the controllers for controlling intensity and wavelength of the
light from the LEDs.
6. Apparatus as in claim 5 wherein the items are labeled with
identification tags and the apparatus further comprises a tag
sensor to detect the identification tags and communicate that
information to at least one of the controllers.
7. Apparatus as in claim 1 further comprising an environmental
sensor coupled to the controller to enable the controller to
control an environmental variable.
8. Apparatus as in claim 1 wherein each array of LEDs includes LEDs
which emit red light and LEDs which emit blue light.
9. Apparatus as in claim 8 wherein each array of LEDs is mounted on
a heat sink, and a temperature sensor is also mounted on the heat
sink in communication with the at least one controller.
10. Apparatus as in claim 2 wherein: each of the tracks comprises
pair of L-shaped members having a first length facing in opposition
to each other; the LEDs are affixed to a heat sink having a second
length less than the first length; and the heat sink is positioned
in the track and is movable along the track.
Description
REFERENCE TO RELATED APPLICATION
[0001] This patent application claims priority from U.S.
Provisional Patent Application Ser. No. 61/699,970, filed Sep. 12,
2012, and entitled "System for Optimized Plant Growth," attorney
docket 94551-851221 (000800US), the contents of which are
incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] This application relates to technology for plant growth, and
in particular, to a lighting system for optimized plant growth
under controlled conditions.
[0003] Growing plants in a controlled environment is now a
well-known technology. Greenhouses produce large quantities of
flowers and vegetables which are distributed throughout the world.
More recently, plants are being grown in yet further controlled
environments, for example, where all of the light and nutrients are
provided in a closed, essentially windowless structure. While such
systems can use incandescent lighting, the reduced power
consumption and higher efficiency of light-emitting diodes (LEDs)
have made those the preferred choice for "indoor" greenhouses. We
use the term "indoor" herein to refer to systems in which plants
are grown with minimal or no exposure to ambient lighting--that is,
systems in which essentially all of the light provided for plant
growth is provided from artificial sources such as light-emitting
diodes.
[0004] One example of this technology is known as "vertical"
farming, i.e., growing herbs and vegetables in soil positioned in
growing tubs placed in racks inside a closed building. This allows
control of light, water, and nutrients. The closed environment
dramatically reduces the amount of water required, while the
ability to grow the produce on shelves of stacked racks
dramatically reduces the square footage required to produce a given
amount of produce. The light sources are positioned directly above
and close (less than 12 inches) to the plants. This system is
essentially a two-dimensional application of light; typically, the
plants do not grow more than six inches in height before harvest.
Accordingly, this application requires uniform light distribution
from above radiating downward onto the target area. It also
requires a reflective mounting structure to capture light reflected
from the plants that would otherwise be lost, plus modularity for
scaling, ease of installation, and low cost.
BRIEF SUMMARY OF THE INVENTION
[0005] Our system for enabling controlled growth of plants in
containers includes a set of linear tracks spaced apart from each
other. Supporting plates position the tracks in a parallel
arrangement. Each track includes an array of blue and red LEDs
affixed to a heat sink which can slide along the track to be
positioned in a desired position to the container beneath it. A
controller for the LEDs is situated between every other pair of
tracks to control adjacent arrays of LEDs. The controller controls
the LEDs to provide light of desired intensity and wavelength to
the plants.
[0006] By making each track identical to all other tracks and
making each supporting plate identical to all other supporting
plates, the apparatus may be enlarged or reduced in a modular
manner to an appropriate size for the configuration of the plant
growth system. By positioning a light sensor in proximity to the
containers and coupling it to at least some of the controllers, the
intensity and wavelength of the light from the LEDs can be adjusted
as needed for the particular plants and stage of plant growth. In
addition, if the containers are labeled with identification tags,
e.g., RFID, and also provide the apparatus with a tag sensor which
detects the identification tags, the system can be controlled
automatically. Furthermore, in some embodiments an environmental
sensor is coupled to the controller to enable the controller to
control an environmental variable such as temperature or humidity.
Preferably, each array of light-emitting diodes includes only blue
and red light-emitting diodes mounted on a heat sink, with a
temperature sensor also mounted on the heat sink in communication
with the controller.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a top view of a light-emitting diode (LED)
assembly for plant growth;
[0008] FIG. 2 is a perspective view of the assembly;
[0009] FIG. 3 is a diagram of an LED array strip;
[0010] FIG. 4 is a perspective view of the assembly as implemented
in a typical environment; and
[0011] FIG. 5 is a block diagram illustrating a controller for the
system.
DETAILED DESCRIPTION OF THE INVENTION
[0012] FIG. 1 is a top view of a light-emitting diode apparatus 10
used for plant growth. Shown in the diagram are a series of tracks
20 having spaced-apart side rails. Positioned within each track is
a light-emitting diode (LED) assembly 30 which includes strips of
LEDs affixed to a heat sink. The LED/heat sink assembly 30 is
preferably not affixed to the track 20, enabling it to be
positioned in the track in a desired relationship to the container
beneath it. The LEDs are electrically coupled to controllers 40
disposed on the plates 50 of apparatus 10.
[0013] Each pair of tracks 20 is held in a fixed position with
respect to other tracks by an intervening supporting plate 50. The
plates 50 and tracks 20 enable a modular approach to the system in
which additional sub-assemblies consisting of a plate and a track
can be added to extend the length of the assembly as needed by the
particular application.
[0014] FIG. 2 is a perspective view illustrating the apparatus in
more detail. As shown, the individual tracks 20 each consist of a
pair of L-shaped side rails 28 mounted in opposition to each other
to provide a lower surface 29 upon which the LED assembly 30 is
supported. The heat sink of each LED assembly 30 is not affixed to
the track 20, but may be moved to and fro in the track 20 as
indicated by the bi-directional arrow 32.
[0015] Also illustrated is a strip-shaped circuit board of LEDs 60
affixed to the lower surface of the heat sink. In the preferred
embodiment, an LED circuit board of LEDs 60 consists of a linear
row of blue LEDs disposed in parallel to a linear row of red LEDs.
Wires, not shown, couple the strip of LEDs 60 to the controller 40.
The intervening plates 50 between each pair of tracks 20 provide an
attachment surface for the controller 40, and for tabs 22 on track
20.
[0016] FIG. 3 illustrates the LED circuit board 62 in more detail.
Arranged in a linear manner along one edge of the circuit board 62
are LEDs 70 of a first color. Along the other edge of the circuit
board 62 are LEDs 75 of a different color. Preferably the two
colors are red and blue. Each circuit board of LEDs 70, 75 also
preferably includes a thermistor 80, or other sensor, for measuring
the temperature of the assembled circuit board 62 and heat sink.
This allows more careful control of the temperature of the circuit
board 62 and LEDs 60, enabling longer life for the LEDs. A
connector 90 coupled to the LEDs 60 and the thermistor 80 enables
electrical connections to be made between the LED assembly 60 and
the controllers 40.
[0017] FIG. 4 is a diagram illustrating an application for the
system described in FIGS. 1-3. As shown in the FIG. 4, a frame 100
supports a series of trays 110 in which plants are being grown.
Each tray includes soil with appropriate nutrients and water added
as necessary. Positioned linearly above the row of trays 110 is the
apparatus 10 described in conjunction with FIGS. 1-3. Positioned
above the apparatus 10 is another row of trays 109 supported on an
additional portion 120 of the frame 100. Above the additional row
of trays 109 is another LED assembly (not shown) to provide
illumination to that row of trays.
[0018] A series of sensors 130 are mounted along the side rails of
the frame 100 to detect the light emitted by the apparatus 10, and
to detect environmental conditions in the vicinity of the
apparatus. The sensors 130 are coupled to the controllers 40 to
provide the controllers information about the color and intensity
of the light being emitted by the strips of LEDs 60.
[0019] Generally, most plants absorb primarily blue and red light.
With appropriate experimental testing and calculations, the
apparatus described here provides an optimal mix of wavelengths of
light ranging from all blue to all red, each with a controlled
intensity. For example, some plants grow best with primarily blue
light at the beginning of their growth, and later predominately red
light. The apparatus described here enables such control.
[0020] The sensors positioned along the trays provide information
about the color of the light being received. In addition, those
sensors can also provide information about temperature, humidity,
reflected light, carbon dioxide content, or other parameters of
interest at the location of the trays with the plants. The sensors
can provide feedback to control systems within the facility to
raise or lower the temperature, humidity, carbon dioxide content,
etc. In this manner, water use can be limited and power consumption
made appropriate for the needs of the plant at the time.
[0021] Furthermore, in a preferred embodiment, an RFID tag can be
added to each of the trays, where this identification is sensed by
RFID sensors 160 on the frame 100. If the RFID tag information also
provides information about the content of the tray, the light color
and intensity of the LED emissions can be optimized for that
particular plant type, even as the trays are moved to other
locations on the supporting frames.
[0022] FIG. 5 is a block diagram illustrating a control system for
the apparatus illustrated in FIGS. 1-3. As shown, the trays 110
containing plants are positioned under the strips of LEDs 60 which
are supported by the frame 100. A light sensor (photo detector) 130
is positioned in proximity to the tray 110 to detect the light
provided by the LEDs 60, and to relay that information over a
connection 135 to a controller 40. Depending upon the particular
plants and the stage of their growth, controller 40 provides
signals over bus 140 to control the color and intensity of the
light by controlling the LEDs 60. The particular tray 110 and its
contents are identified to the controller 40 by an RFID tag 150.
The RFID tag 150 communicates with an RFID sensor 160 which
provides that information to a controller 40 using a connection
165. An environmental sensor 170 provides information to controller
40 about desired environmental variables, for example, temperature,
humidity, carbon dioxide, etc. By coupling controller 40 to fans,
heaters, or other apparatus, the environmental conditions in the
vicinity of the trays 110 can therefore also be controlled.
[0023] Of course, while above we describe the structure and system
described here in terms of an application for optimized plant
growth, it will be apparent that the system described can have
other uses, for example, in any circumstance in which controlling
light output in a manufacturing process is important. For example,
in the manufacture of products where photoresist is used,
controlling the color and intensity of light can provide superior
results.
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