U.S. patent application number 09/899032 was filed with the patent office on 2001-12-13 for battery-powered wireless remote-control motorized window covering assembly having controller components.
This patent application is currently assigned to Hunter Douglas Inc.. Invention is credited to Colson, Wendell B., Gaudyn, Erwin, Holford, Michael S., Jarosinski, Marek, Kovach, Joseph E., Skinner, Gary F., Vogel, David.
Application Number | 20010050538 09/899032 |
Document ID | / |
Family ID | 27556061 |
Filed Date | 2001-12-13 |
United States Patent
Application |
20010050538 |
Kind Code |
A1 |
Kovach, Joseph E. ; et
al. |
December 13, 2001 |
Battery-powered wireless remote-control motorized window covering
assembly having controller components
Abstract
A wireless battery-operated window covering assembly is
disclosed. The window covering has a head rail in which all the
components are housed. These include a battery pack, an interface
module including an IR receiver and a manual switch, a processor
board including control circuitry, motor, drive gear, and a
rotatably mounted reel on which lift cords wind and unwind a
collapsible shade. The circuitry allows for dual-mode IR receiver
operation and a multi-sensor polling scheme, both of which are
configured to prolong battery life. Included among these sensors is
a lift cord detector which gauges shade status to control the
raising and lowering of the shade, and a rotation sensor which, in
conjunction with internal registers and counters keeps track of
travel limits and shade position.
Inventors: |
Kovach, Joseph E.;
(Thornton, CO) ; Holford, Michael S.; (Broomfield,
CO) ; Skinner, Gary F.; (Westminster, CO) ;
Jarosinski, Marek; (Brighton, CO) ; Gaudyn,
Erwin; (Westminster, CO) ; Vogel, David;
(Thornton, CO) ; Colson, Wendell B.; (Boulder,
CO) |
Correspondence
Address: |
PENNIE & EDMONDS LLP
1667 K STREET NW
SUITE 1000
WASHINGTON
DC
20006
|
Assignee: |
Hunter Douglas Inc.
2 Park Way & Route 17 South
Upper Saddle River
NJ
07458
|
Family ID: |
27556061 |
Appl. No.: |
09/899032 |
Filed: |
July 6, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09899032 |
Jul 6, 2001 |
|
|
|
09692491 |
Oct 20, 2000 |
|
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|
Current U.S.
Class: |
318/16 |
Current CPC
Class: |
E06B 9/32 20130101; Y10S
388/933 20130101 |
Class at
Publication: |
318/16 |
International
Class: |
H02P 001/00; H04Q
007/00; H04Q 009/00 |
Claims
What is claimed is:
1. A battery-powered remote-control motorized window treatment
assembly having a window covering movable between a lowered
position and a raised position, comprising: a head rail; a
reversible dc motor associated with the head rail and operatively
coupled to the window covering; at least one battery associated
with the head rail and configured to power the reversible dc motor;
a manual switch mounted on the head rail and configured to output a
manual control signal when the manual switch is activated; a remote
control sensor configured to detect a user-generated wireless
remote control signal and output a sensed remote control signal in
response thereto; and an integrated circuit controller electrically
connected to said light sensor, the controller configured to
respond to at least two different light signals, the controller
configured to cause the reversible dc motor to turn in a first
direction in response to first information present in a first light
signal, and further configured to cause the reversible dc motor to
turn in a second direction in response to second information
present in a second light signal, said controller having a
plurality of connections including: a ground connection; a voltage
supply input; a first position input configured to receive
information reflective of either a movement or a position of said
window covering; a manual signal input configured to receive said
manual control signal from said manual switch; a remote signal
input configured to receive an output from said light sensor, said
output resulting from a user-generated infrared remote-control
signal; and first and second motor drive signal outputs, each motor
drive signal output configured to output a motor drive signal to
energize the motor to turn in one of two directions, in response to
either a valid user-generated light signal or a manual control
signal.
2. The assembly of claim 1, wherein the remote control sensor is a
light sensor configured to receive a user-generated infrared light
signal from a remote control infrared transmitter.
3. The assembly of claim 2, wherein the light sensor is an infrared
receiver having a power supply lead, a ground lead and an output
lead, the infrared receiver configured to detect and demodulate
said user-generated infrared light signal.
4. The assembly of claim 2, wherein the assembly is provided with a
daylight-blocking window positioned in front of said light sensor
to help reduce ambient light impinging on the light sensor.
5. The assembly of claim 1, wherein the controller retains position
information reflective of a vertical position of said window
covering.
6. The assembly of claim 1, wherein the first position input is
configured to receive pulses from a sensor while the window
covering is moving.
7. In a window treatment assembly having a head rail and a window
covering movable between a lowered position and a raised position,
the improvement comprising: a reversible dc motor associated with
the head rail and operatively coupled to the window covering; at
least one battery associated with the head rail and configured to
power the reversible dc motor; a manual switch mounted on the head
rail and configured to output a manual control signal when the
manual switch is activated; a remote control sensor configured to
detect a user-generated wireless remote control signal and output a
sensed remote control signal in response thereto; and an integrated
circuit controller electrically connected to said light sensor, the
controller configured to respond to at least two different light
signals, the controller configured to cause the reversible dc motor
to turn in a first direction in response to first information
present in a first light signal, and further configured to cause
the reversible dc motor to turn in a second direction in response
to second information present in a second light signal, said
controller having a plurality of connections including: a ground
connection; a voltage supply input; a first position input
configured to receive information reflective of either a movement
or a position of said window covering; a manual signal input
configured to receive said manual control signal from said manual
switch; a remote signal input configured to receive an output from
said light sensor, said output resulting from a user-generated
infrared remote-control signal; and first and second motor drive
signal outputs, each motor drive signal output configured to output
a motor drive signal to energize the motor to turn in one of two
directions, in response to either a valid user-generated light
signal or a manual control signal.
8. The assembly of claim 7, wherein the remote control sensor is a
light sensor configured to receive a user-generated infrared light
signal from a remote control infrared transmitter.
9. The assembly of claim 8, wherein the light sensor is an infrared
receiver having a power supply lead, a ground lead and an output
lead, the infrared receiver configured to detect and demodulate
said user-generated infrared light signal.
10. The assembly of claim 8, wherein the assembly is provided with
a daylight-blocking window positioned in front of said light sensor
to help reduce ambient light impinging on the light sensor.
11. The assembly of claim 7, wherein the controller retains
position information reflective of a vertical position of said
window covering.
12. The assembly of claim 7, wherein the first position input is
configured to receive pulses from a sensor while the window
covering is moving.
13. In a battery-powered remote-control motorized window treatment
assembly having a window covering movable between a lowered
position and a raised position, the assembly including: a head
rail; a reversible dc motor disposed in the head rail and
operatively coupled to the window covering; at least one battery
mounted in the head rail and configured to power the reversible dc
motor; a manual switch mounted on the head rail and configured to
output a manual control signal when the manual switch is activated;
and a remote control sensor configured to detect a user-generated
wireless remote control signal and output a sensed remote control
signal in response thereto; the improvement comprising: an
integrated circuit controller electrically connected to said light
sensor, the controller configured to respond to at least two
different light signals, the controller configured to cause the
reversible dc motor to turn in a first direction in response to
first information present in a first light signal, and further
configured to cause the reversible dc motor to turn in a second
direction in response to second information present in a second
light signal, said controller having a plurality of connections
including: a ground connection; a voltage supply input; a first
position input configured to receive information reflective of
either a movement or a position of said window covering; a manual
signal input configured to receive said manual control signal from
said manual switch; a remote signal input configured to receive an
output from said light sensor, said output resulting from a
user-generated infrared remote-control signal; and first and second
motor drive signal outputs, each motor drive signal output
configured to output a motor drive signal to energize the motor to
turn in one of two directions, in response to either a valid
user-generated light signal or a manual control signal.
14. The assembly of claim 13, wherein the remote control sensor is
a light sensor configured to receive a user-generated infrared
light signal from a remote control infrared transmitter.
15. The assembly of claim 14, wherein the light sensor is an
infrared receiver having a power supply lead, a ground lead and an
output lead, the infrared receiver configured to detect and
demodulate said user-generated infrared light signal.
16. The assembly of claim 14, wherein the assembly is provided with
a daylight-blocking window positioned in front of said light sensor
to help reduce ambient light impinging on the light sensor.
17. The assembly of claim 13, wherein the controller retains
position information reflective of a vertical position of said
window covering.
18. The assembly of claim 13, wherein the first position input is
configured to receive pulses from a sensor while the window
covering is moving.
Description
RELATED APPLICATIONS
[0001] This is a continuation of 09/692,491, filed Oct. 20, 2000,
now U.S. Pat. No. 6,259,218, which is a continuation of 09/532,011,
filed Mar. 21, 2000, now U.S. Pat. No. 6,181,089, which is a
continuation of 09/357,761, filed Jul. 21, 1999, now U.S. Pat. No.
6,057,658, which is a continuation of 09/131,417, filed Aug. 10,
1998, now U.S. Pat. No. 5,990,646, which is a continuation of
08/757,559, filed Nov. 27, 1996, now U.S. Pat. No. 5,793,174, which
claims priority to provisional application no. 60/025,541, filed
Sep. 6, 1996.
TECHNICAL FIELD
[0002] This invention relates to electrically powered window
coverings such as vertically adjustable shades, tiltable blinds and
the like. More particularly, the invention relates to motorized
window coverings which are activated by a wireless remote control
transmitter and have associated with them a DC motor and electrical
and mechanical circuitry adapted to store position information.
BACKGROUND
[0003] Wireless, remote control, motorized window coverings are
activated by a control signal generated and sent by a transmitter.
As explained in U.S. Pat. No. 4,712,104 to Kobayashi, the control
signal is usually converted into one of audio, radio (RF), or light
(either visible or, more preferably, infrared (IR)) energy, and
transmitted through the air. When a button on a remote transmitter
is pushed, the control signal comprising one of these types of
energy is generated. The control signal sent by the transmitter may
comprise a carrier signal which modulates either a continuous
waveform or, more preferably, a sequence of spaced apart pulses. In
those cases where spaced apart pulses are used, the pulses may
either be coded, or they may comprise a sequence of pulses having
substantially identical pulse widths and a constant pulse
repetition frequency (PRF).
[0004] Each wireless, remote control motorized window covering
system is provided with at least one transducer which converts the
transmitted energy into electrical signals. In the case of an audio
signal, the transducer is a microphone. In the case of RF signal,
the transducer is likely to be an antenna, which may comprise an
electromagnetic coil tuned to the carrier frequency. Finally, in
the case of a light signal, the transducer is typically a
photodiode, a photoresistor or a phototransistor.
[0005] As the signal travels from the transmitter to the
transducer, it may become slightly corrupted. For instance, in the
case of an acoustic signal, environmental noise in frequencies of
interest, may be added to the signal. In the case of a light
signal, light from other sources may be added to the received
signal. Further corruption may take place as the transmitted signal
is converted by the transducer into an electrical signal. This is
because all transducers, however precise, cannot output an
electrical signal which perfectly replicates the incoming
transmitted signal. Usually, the electrical signal from the
transducer will vary slightly from what was transmitted.
[0006] In addition to being corrupted, the signal may have also
been modulated before transmission, as explained above. Together,
these factors result in a signal that is distorted, and may be
unintelligible to a decision circuit, described further below. To
help correct some of this distortion, the electrical signal from
the transducer is usually preprocessed before it is interpreted by
a decision circuit. The goal of this preprocessing is to convert
the electrical signal from the transducer to a form that can be
used, and is less likely to be mis-interpreted, by the decision
circuit. This process is loosely referred to as "cleaning up" the
signal.
[0007] Cleaning up a signal from a transducer may involve filtering
and demodulating a signal, as is often necessary with RF and IR
signals. It may also involve waveshaping using comparators,
inverters and triggers which have hysteresis-like input/output
relationships, as disclosed in U.S. Pat. No. 5,275,219 and Canadian
Patent No. 1,173,935 to Yamada, both of which are directed to
motorized window systems which respond to daylight. In the case of
IR signals, an integrated IR receiver, having a photodiode or a
phototransistor, signal amplifiers, bandpass filters, demodulators,
integrators and hysteresis-like comparators for waveshaping,
perform such a function. The IS1U60, available from Sharp
Electronics, is such a receiver, and can be used in remote control
operations.
[0008] As stated above, in a remote control system, the cleaned up
control signal is presented to a decision circuit. The role of the
decision circuit is to determine a) whether the cleaned up control
signal is valid, i.e., whether or not the signal content is such
that the system should respond, and b) what, if any, response
should be taken, in view of the control signal content and other
status information.
[0009] The decision circuit comprises additional sensors, switches
and registers, which keep track of such things as the direction of
last motion, the position of the window covering relative to its
travel extremes, and other status information. The decision circuit
may be formed entirely from a combination of discrete analog and
digital components, in which case the decision circuit is said to
be hardwired. Alternatively, the decision circuit may include a
microprocessor, microcontroller, or equivalent, in which case the
decision circuit is said to be programmable. As is known to those
skilled in the art, incorporating a microprocessor, or the like,
allows for more complex decision making with the control signals
and other status information.
[0010] All decision making circuits, whether or not they
incorporate a microprocessor, are connected to a motor circuit
adapted to drive a DC motor. Although the exact implementation of a
motor circuit may differ, they all serve to connect the source of
power, be it a battery, a solar cell, or even an AC-to-DC
transformer, to the motor to operate the window covering. A typical
motor circuit is disclosed in U.S. Pat. No. 4,618,804 to Iwasaki.
In this circuit, two signals from the drive circuit are used to
activate a pair of transistors. In such a motor circuit, upon
receipt of an "UP" motor signal from the decision circuit, current
flows from the voltage source, through a first transistor, the
motor, and a second transistor to drive the motor in a first
direction (e.g., clockwise). And, upon receipt of a "DOWN" motor
signal, current flows from the voltage source through a third
transistor, the motor, and a fourth transistor to drive the motor
in an opposite direction (e.g., counterclockwise).
[0011] The power supply for a motorized window covering system may
originate from an alternating current (AC) source, as shown in U.S.
Pat. No. 3,809,143 to Ipekgil. In such case, one plugs into a wall
socket and a transformer, or the like, is used to convert the AC
into DC. As an alternative to using an AC power source, the power
supply may comprise a battery, which may be recharged by a solar
cell and/or by plugging into an AC source. U.S. Pat. No. 4,664,169
to Osaka discloses such a battery-operated lift system which moves
a bottommost supporting slat relative to a headrail.
[0012] In wireless, remote-controlled motorized systems having an
AC power source, there is little concern about designing the system
to minimize energy consumption. This is because the AC source
provides, for all practical purposes, virtually unlimited power. On
the other hand, when a battery, especially one that cannot be
recharged, is used, the current draw of the system becomes a design
concern. This is because the transducer must always be available to
receive a transmitted control signal. Also, the preprocessing,
decision making and motor drive circuitry must be prepared to
respond immediately, which usually means that they are, at the very
least, in a "standby mode", which also draws at least some
current.
[0013] In the case of battery powered systems, there are three
general approaches to conserving battery power. One approach is to
use low-power, discrete analog and digital components which are on
at all times, whether or not a valid control signal is received.
This is the approach taken in U.S. Pat. No. 5,495,153 to Domel et
al., which calls for using low dark-current phototransistors, and
low-power logic devices such as NAND gates, counters, flip flops,
power saving resistors, and the like. A second approach is to cycle
one or more components on and off while waiting for a valid signal.
This is the approach taken in U.S. Pat. No. 5,134,347 to Koleda,
which calls for turning an IR receiver on for a brief period of
time, and then allowing it continue to stay on longer if it
receives a valid signal. The approach taken in Koleda is based on
well-settled techniques for reducing the duty cycle of a receiver
powered by a battery, as disclosed in U.S. Pat. No. 4,101,873 to
Anderson et al. Finally, the third approach of conserving battery
power is to use a solar cell to continuously recharge the
batteries. U.S. Pat. No. 4,644,990 to Webb discloses a
photosensitive energy conversion element which recharges batteries
used to supply power to automatic system for tilting blinds.
[0014] To operate a window covering, the motor is typically placed
in a headrail where it is hidden from view. A rod, to which the
motor is operatively engaged, is rotatably mounted in the headrail.
When the rod rotates, cords connected at one end to the rod, and
also connected to the shade or blinds, can be wound either directly
on the rod or on a spool arranged to turn with the rod in a lift
system. U.S. Pat. No. 4,550,759 to Archer shows such a system for
controlling the tilt of a blind, and U.S. Pat. No. 4,856,574 to
Minami shows a motorized system for controlling the lift of a
horizontal slat.
[0015] The extent of travel for a window covering can be limited by
a counter, which uses dead reckoning to keep track of the number of
rotations of the motor or the rod, relative to a stored counter
value. In such case, the rotating wheel, or the like interrupts an
optical or a magnetic path, and these interruptions are counted.
Such systems are shown in the aforementioned Minami '574
reference.
[0016] As an alternative to "dead reckoning", limit switches may be
used to control the extent of movement of the window covering.
Limit switches are mechanical switches which are activated by
engagement with a member of the system during the latter's
operation. In the typical case, the limit switches are stationary
and are abutted by a movable member of the motorized system. U.S.
Pat. No. 4,727,918 to Schroeder discloses the use of limit switches
in the headrail to control the tilt of a blind. Along similar
lines, Danish patent No. 144,894 to Gross discloses the use of
limit switches in the headrail to control the lift of a shade.
[0017] It should be noted here that we have used the word "shade"
to generically describe a window covering which could be raised and
lowered. This word encompasses such window coverings as venetian
blinds comprising horizontal slats, pleated shades, accordion
shades, and the like. As is known to those skilled in the art,
pleated and accordion shades are typically formed from a
lightweight fabric, and thus are often lighter than the more rigid
slats. Because of this, it is generally accepted that mechanisms
having sufficient torque to raise and lower horizontal slats, can
also raise and lower lightweight shades.
[0018] Finally, in the typical remote control motorized system, the
transducers, circuitry, motors, and servo mechanisms used to
operate one type of window covering, can often be adapted to
operate other types. For instance, as explained in International
Publication WO 90/03060 to Roebuck, a motor/servo arrangement
capable of opening and closing vertical slats and also drawing
them, can readily be adapted to venetian blinds (horizontal slats)
and the like. Similarly, EPO 381,643 to Archer shows that a DC
motor mounted in headrail and connected to rotatably mounted rod
can lift horizontal slats or pleated shades with virtually no
modifications.
[0019] The prior art also includes systems which combine a large
number of the features discussed above. For instance, there are
wireless, remote-control lift systems having a headrail-mounted DC
motor which winds a lift cord around a rod, and which has
additional novel features. One such example is the battery-powered
device of U.S. Pat. No. 5,029,428 to Hiraki, which is placed
between the panes of a double-pane window. Another, is the
IR-controlled, AC-powered, microprocessor-based device of Japanese
Laid-open application 4-237790 to Minami, which provides for a
programmable lower limit for the shade using the transmitter.
SUMMARY OF THE INVENTION
[0020] The present invention provides a battery-powered, wireless,
remote-control, microprocessor-driven, motorized window covering
assembly having the batteries, motor, drive gear, a rotatably
mounted reel around which is lift cord is wound for raising and
lowering a shade, circuitry and sensors, all housed in a headrail,
making the resulting device more visually appealing.
[0021] One aspect of the invention is that the assembly's circuitry
is configured to prolong the life of the batteries. In this regard,
the IR receiver is alternately turned on and off in one of two
power states which differ only in the length of the on-off power
cycle. Peripheral sensors are also operated only on an as-needed
basis, under microprocessor control to further prolong battery
life. These sensors, along with flags, timers and registers
controlled by the microprocessor, are arranged to restrict motor
operation under inappropriate conditions, thereby both prolonging
battery life and preventing damage to the assembly.
[0022] Another aspect of the present invention is that the assembly
having a detector which engages the lift cord to determine when the
shade has either been fully lowered, or alternatively, has met with
an obstruction, the detector being used to control both the
downward movement of the shade, and also the upper limit of shade
travel, in conjunction with a remote control transmitter.
[0023] Yet another aspect of the present invention is a resilient,
vibration dampening bushing which mounts the motor onto the head
rail, thereby reducing vibrations transferred to the head rail and
also to the rod. This not only helps dissipate energy imparted to
the headrail, but also reduces annoying acoustic noise.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a perspective view of a window covering assembly
in accordance with the present invention.
[0025] FIG. 2 is an end view of the assembly shown in FIG. 1.
[0026] FIG. 3 is a top view of the head rail.
[0027] FIG. 4 is a partially foreshortened front view of the
assembly.
[0028] FIG. 5 is a sectional view taken along line 5-5 in FIG.
3.
[0029] FIG. 6 is a sectional view taken along line 6-6 in FIG.
3.
[0030] FIG. 7 is a perspective view of the lift cord which engages
the reed switch.
[0031] FIG. 8 is a perspective view of the assembly of FIG. 1, with
the front panel raised.
[0032] FIG. 9 is an enlarged perspective view of the motor and
transmission assembly and mounting therefor.
[0033] FIG. 10 is a side elevation view of the mounting bushing
shown in FIG. 9.
[0034] FIG. 11 is a front elevation view of the mounting bushing
shown in FIG. 10.
[0035] FIG. 12 is a perspective view of a drive rod including a
counter wheel.
[0036] FIG. 13 is a block diagram of a control circuit utilized in
the present invention.
[0037] FIG. 14 is a circuit diagram of the power supply of FIG.
13.
[0038] FIG. 15 is a circuit diagram of the processor
connections.
[0039] FIG. 16 is a circuit diagram of the interface module.
[0040] FIG. 17 is a circuit diagram of the sensor subcircuit.
[0041] FIG. 18 is a circuit diagram of the bridge circuit.
[0042] FIGS. 19, 19A-19J present a flow chart illustrating the
microprocessor controlled operation of the window covering shown in
FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0043] FIG. 1 shows a window covering assembly 100 of the present
invention. The assembly comprises a head rail 102, a bottom rail
104, and a shade 106. Preferably, the head rail 102 and bottom rail
are formed from aluminum, plastic, or some other light weight
materials. The shade 106 shown FIG. 1 is an expandable and
contractible covering preferably made from a light fabric, paper,
or the like. The shade of FIG. 1 is shown to be a cellular
honeycomb shade; however, a pleated shade, horizontal slats, and
other liftable coverings can also be used.
[0044] As seen in FIGS. 1 and 2, the head rail 102 comprises a
bottom panel 108, a back panel 110, end caps 112 and a front panel
114. The front panel 114 is hinged by pins, attached at its upper
end corners, to the end caps 112. This facilitates access to the
cavity 116 within the head rail 102 behind the front panel's front
surface 118. Alternatively, the front panel 114 can be hinged to
the bottom member 108, or even be fully removable and snapped on to
the rest of the head rail.
[0045] A plurality of lift cords 120 descend from within the head
rail 102, pass through the cells of the honeycomb shade 106, to the
bottom rail where they are secured by known means. The weight of
the bottom rail 104 and shade 106 are supported by the lift cords
120, causing the latter to normally undergo tension.
[0046] FIG. 3 shows a top view of the cavity 116. Within the cavity
116 are an elongated tube 150 forming a battery pack which houses
batteries 152 and is mounted on the cavity-facing side of the front
panel 118. The tube 150 is preferably formed from a non-conductive
material such as plastic. Also mounted in the cavity is a motor 122
operatively engaged to a rotatably mounted reel shaft 124, around
which reel shaft the lift cords 120 are wound and unwound.
Preferably, the reel shaft is hollow to reduce its weight. This
reduces the torque and power requirements, thus extending battery
life. A printed circuit (PC-) board 126 which carries much of the
electronic circuitry of the assembly is also housed in the
cavity.
[0047] As best seen in FIGS. 3 and 4, an interface module 128
communicates between the front surface 118 and the cavity 116. The
interface module 128 comprises an infrared (IR) receiver and a
manual switch 130. On the front surface 118, the manual switch 130
and a daylight-blocking window 132 are visible. The manual switch
130 can be activated by a user at any time. The window 132 covers
the photoreceiver (i.e., transducer) of the IR receiver and helps
extend the life of the batteries by preventing daylight from
needlessly activating the transducer. One skilled in the art would
recognize that an IR receiver, whose transducer has a built-in
daylight-blocking window or a daylight-blocking coating, may also
be used. The important thing is that the transducer not respond to
daylight, and preferably be arranged such that it only responds to
infrared light. It should be noted that the shade has no manually
operated pull cord. Thus, the manual switch 130 on the front panel,
and the IR receiver are normally the only means for operating the
window covering.
[0048] As shown in FIG. 6, the motor 122 and its transmission 134
are operatively connected to a drive rod 136 having a square
cross-section. The drive rod 136 is received by a telescoping reel
shaft 124 which turns in spaced-apart bearings 138, each integrally
formed with a reel support 140. When the drive rod 136 turns, the
reel shaft 124 turns and also telescopes in an axial direction, one
rotation of the reel shaft corresponding to an axial movement
approximately equal to the thickness of the lift cord 120'. Thus,
the lift cord passes through the bottom plate of the head rail at
substantially the same position as it winds and unwinds. Thus, as
seen in FIG. 6, the lift cord 120' is wrapped around the reel shaft
124, each turn abutting its neighbor without overlap, and its end
142 secured to the reel shaft by a ring-shaped clamp 144.
[0049] FIG. 7 illustrates the significance of having a particular
lift cord 120' pass through the bottom panel 108 at the same
position, as it winds and unwinds. A lift cord detector 146, formed
as a reed switch, is mounted on the inside surface of the bottom
panel 108. The lift cord detector 146 is positioned such that the
lift cord 120' abuts the detector's reed 148, when there is tension
in the lift cord 120'. When it abuts the reed 148, the lift cord
120' closes a connection in the switch. In the present design, the
detector's reed 148 must be in abutment with the cord 120' for the
motor 122 to lower the shade.
[0050] There are two situations of interest in which the detector's
reed 148 no longer abuts the lift cord 120' during descent, causing
the motor to stop. The first is when the tension in the lift cord
120' is relaxed. This happens, for example, when the bottom rail
104 meets with an obstruction, such a person's hand or an object on
a window sill. In this first situation, the function of the lift
cord detector 146 is to monitor the tension in the cord 120'.
[0051] The second situation is when the descending shade fully
unwinds the lift cord 120'. In this latter case, as the reel shaft
124 makes its final rotation, it comes to a stop after bringing the
end 142 of the lift cord 120' past the reed 148 and thus, no longer
in abutment therewith. In such case, the lift cord 120' hangs from
the reel shaft 124 in a position that is laterally displaced from
the position it occupied when it was wrapped around the reel shaft
124. In this second situation, the function of the cord detector
146 is to gauge the lateral position of the lift cord 120' as it
hangs from the reel 124.
[0052] It should be noted that the function of gauging the lateral
position of the lift cord may be performed a number of equivalent
means. For instance, if the lift cord is thick enough, an optical
sensor comprising an LED and a photodetector may suffice. The lift
cord 120' would then obstruct the light path in a first lateral
position, and would not obstruct the light path in a second lateral
position. And if the lift cord 120' is formed from a metallic
material, it may also be possible to arrange a magnetic sensor to
detect a lateral movement of the lift cord 120'. Such sensors,
however, would require power to operate, and would not be able to
simultaneously detect tension; therefore, they are not
preferred.
[0053] As shown in FIG. 8, the power supply for the assembly of the
present invention is a battery pack 150 comprising eight 1.5 V AA
batteries 152. The batteries, which preferably are
non-rechargeable, are laid end-to-end, in electrical series with
one another, thus providing 12 volts. The batteries are housed in a
single elongated tube 150 which is mounted via brackets 154 fixed
to the back side 156 of the head rail's front panel 114. With the
batteries 152 laid end-to-end and substantially parallel to the
reel shaft 124, substantially space savings is realized. This
allows the motor, rotatable reel shaft, battery-based power supply,
and electronics to be held within a housing having a cross-section
less than 1 3/4" by 1 3/4".
[0054] A coil spring 158 mounted on the back side 156 biases a
first end of the elongated tube 150, forcing a positive battery
terminal against a positive electrical contact positioned at the
opposite, second end. A conductor strip 160 formed on an outer
surface of the tube 150 connects the negative terminal of the
battery pack 150 to a ring-shaped negative electrical contact 162.
Leads from each contact ultimately provide an electrical connection
from the battery pack 150 to the PC board 126, motor 122 and module
128.
[0055] As depicted in FIG. 9, the motor 122 and its associated
transmission 134 are assembled as a drive unit 164, along with a
protective drive plate 166. The drive plate 166 is formed with an
annular boss 168 through which the drive coupling 170 protrudes. A
pair of diametrically opposed pins 172 secure the drive plate 166,
transmission 134 and motor 122 to each other. This facilitates
assembly of the hardware within the head rail.
[0056] The drive unit 164 is mounted in an elongated aperture 174
formed in a bulkhead 176. The bulkhead itself is rigidly fixed to
the floor of head rail, on the inside surface of the latter's
bottom panel 108. Clips 178 formed on a bulkhead top panel 180 help
retain the drive unit 164.
[0057] As the bulkhead 176 is rigidly fixed to the head rail, any
eccentricity in the motor 122 and drive unit 164 is transferred, in
the form of vibrations, to the entire head rail 102. This vibration
is amplified by the head rail, causing the latter to emit annoying
noises. To reduce vibrations imparted to the bulkhead 176 by the
drive unit 164, a resilient vibration dampening bushing 182 is used
to mate the drive unit to the bulkhead. The bushing 182, which
preferably is formed from neoprene rubber having a Shore A hardness
of between 60-70, has a substantially cylindrical base member 184.
The base member 184 is provided with a central aperture 186 shaped
and sized to receive the annular boss 168 formed on the drive plate
166, and is further provided with a pair of apertures 188 adapted
and positioned to receive the pins 172. On one side of its
cylindrical base 184, the bushing 178 is provided with an elongated
boss 190 integrally formed therewith. The elongated boss is shaped
and sized to be received by the elongated aperture 174 in the
bulkhead. In this manner, the bushing 182 both supports the drive
unit 164 within the head rail, and also provides vibration
dampening to reduce motor noise during operation of the window
covering 30.
[0058] As shown in FIG. 12, one end of the drive rod 136 is
integrally formed with a flange 192. Preferably they are formed
from a hard plastic, or the like. The flange 192 is rotatably
mounted between a pair of upstanding ribs 194 supported on the
inside surface of the head rail's bottom panel. The ribs prevent
the drive rod 136 from moving in an axial direction as it is
turned. One end of drive shaft 196 is connected to the drive rod
136 at the flange 192. The opposite end of the drive shaft 196 is
adapted to engage the transmission coupling 170 at a point between
the bulkhead 176 and the flange 192. Thus, coupling 170, drive
shaft 196, flange 192 and drive rod 136 all turn together when the
motor is operated.
[0059] Mounted on the drive shaft 196 is a star wheel 198, which
has four equidistantly spaced, radial spokes 200. The star wheel
198 turns with the drive shaft 196 and the spokes interrupt a path
between two objects, represented by 206a, 206b. As the star wheel
turns, the number of such interruptions is counted by a rotation
counter. This number can then be translated into the number of
revolutions of the reel shaft 124 relative to some starting point.
The value in the rotation counter may then be used to compare with
an upper or a lower limit count value saved in a memory
register.
[0060] Either magnetic or optical sensing may be used in
conjunction with the spokes 200. For magnetic sensing, a permanent
magnet 202 is attached, by adhesive or equivalent means, to the
radially outward end of each spoke 200. A magnetic sensor 204
comprising a pair of spaced apart sensor bars 206a, 206b is mounted
on the underside of the PC-board 126. As the star wheel 198 turns
with the drive shaft, its magnet-tipped spokes 200 pass between the
sensor bars. The number of resulting magnetic disturbances is then
counted, and this number is used in the position determination.
[0061] Alternatively, instead of a magnetic sensor, an optical
sensor may be used. In such case, a light emitting diode (LED)
206a, arranged to emit light having a narrow wavelength, is
positioned on one side of the star wheel 198. A phototransistor
206b responsive to that wavelength is positioned on the other. The
LED and phototransistor are used to count interruptions by the
spokes, as disclosed in U.S. Pat. No. 4,856,574 to Minami, whose
contents are incorporated by reference in their entirety.
[0062] In the present invention, to extend battery life, the
magnetic sensor, or, alternatively, the LED and phototransistor,
are powered and monitored only when the motor is running. More
specifically, they are powered just an instant before the motor is
activated, and they are turned off just after the motor stops
running.
[0063] FIG. 13 presents a block diagram of the circuit 210 used to
control the shade 106. The battery pack 150 supplies all power to
the circuit 210 via a power supply 212. Power supply 212 provides
battery protection, noise filtering and voltage regulation. It also
outputs a 12 volt supply to power the motor, and a 5 volt supply to
power the rest of the circuit.
[0064] The heart of the circuit is a microprocessor 214, part no.
16C54. This processor is advantageous in that any port pin can be
used for input or output. Also, an output port can put out a 5 volt
signal capable of driving 25 mA of current. Thus, the processor
itself acts as a low-current power supply of sorts. The processor
is provided with a central processing unit, a non-volatile
read-only memory (ROM), and a random access read-write memory
(RAM). The ROM stores executable program code which is
automatically entered upon booting the circuit by connecting the
batteries. Alternatively, if a POWER ON switch is provided, this
code is entered when such a switch is activated. The RAM includes a
number of memory locations used for maintaining position data,
status data, signal flags and the like. To extend battery life when
there is no activity, the processor is cycled between a quiescent
state and a sleep state. A built-in watchdog timer wakes up the
processor from the sleep state. In the quiescent state, the
processor 214 check a manual switch 130 and an IR receiver 216 to
see if there are any inputs to which it should respond. If there
are, the processor then enters an active state to process the input
and take any other necessary action in response thereto. Upon
conclusion of the active state, the processor is returned to the
sleep state, after which the quiescent/sleep cycle is resumed.
[0065] The processor 214 is connected to the interface module 128.
A 5 volt power line, IRSIG, and a ground connection are supplied by
the processor to the interface module 128. Two signal lines, one
from the manual switch 130, MAN, and another from the IR receiver
216, IRSIG, are returned to the processor.
[0066] The manual switch 130 can be either a contact switch, which
activates a motor only when it is being depressed. Alternatively,
switch 130 can be a single throw switch, which is activated once to
start the motor, and activated a second time to stop the motor,
unless, the motor stops by itself for some other reason. Either
type of switch can be used, so long as the microprocessor 214 is
appropriately programmed. Regardless of which type of switch is
used, the switch output is presented on line MAN and this is read
by the processor 214.
[0067] In the preferred embodiment, an IR transmitter 218 having
separate UP 220a and DOWN 220b buttons is used to remotely activate
the shade. The IR transmitter is also provided with a two-position
channel selection switch 222, which allows a user to choose between
two channels, A and B. The channel selection feature is especially
advantageous in rooms where more than one window covering assembly
is to be installed.
[0068] When either the UP or the DOWN button is pushed, a coded
sequence of pulses corresponding to the button pushed and the
channel selected, is generated. This sequence comprises a command
signal. Each sequence has an identical number of pulses, and the
sequence is repeated as long as the button is depressed. Each pulse
in a sequence has a predetermined width of between 0.8 and 2.8 msec
and is modulated with a 38 kHz carrier before being
transmitted.
[0069] In the preferred embodiment, the IR receiver is a TFMS 5..0,
available from TEMIC Telefunken. It filters and demodulates the
sensed command signal and outputs a sequence of pulses
corresponding to that generated within the transmitter 218 before
being modulated. These pulses are output on line IRSIG and are read
by the processor 214 by sampling to determine the length of each
pulse. After reading the incoming sequence, the processor 214
matches it against a reference sequence stored in ROM. If a match
occurs, the processor then sends out the appropriate signals to
energize the motor, if other conditions are met.
[0070] To extend the life of the battery, the IR receiver 216 is
cycled on and off by the processor 214 in one of two power cycle
modes, a first, "look" mode, and a second, "active" mode. With no
sensor activity and the motor off, the receiver 216 is normally in
the look mode. In the look mode, power to the receiver 216 is
alternatingly turned off for about 300 msecs, and then turned back
on for about 7.1 msec. This means that, on average, a user must
depress a transmitter button for about 1/3 second before any
response can be expected. During the 7.1 msecs in which the
receiver is powered, the processor checks the receiver output every
33 .mu.secs to see if a valid pulse, i.e., one between 0.8 and 2.8
msecs, has been received. Whether or not one has been received, the
receiver 216 is turned off.
[0071] If no valid pulse has been received, the receiver is allowed
to remain in the look mode. If, however, the microprocessor
determines that a valid pulse was received, it then shifts the
receiver into the active mode. In this mode, the receiver remains
off for 9.5 msecs, and then is turned on for about 46 msecs, and a
new alternating cycle of 9.5 msecs off and 46 msecs on, is
established. When it is in the active mode, the receiver's output
is checked by the processor every 160 .mu.secs. In the active mode,
valid pulses, and even valid sequences of pulses (i.e., those
sequences capable of activating the motor), may be received and
interpreted by the processor 214.
[0072] If neither a valid pulse, nor a valid sequence is received
in that first 46 msec period of the active mode, the processor
shifts the receiver back to the look mode beginning with the next
off cycle. If, instead, a valid sequence is received, the processor
214 and associated circuitry turn on the motor 122, and the
receiver is allowed to remain in the active mode as long as the
motor is running. Thus, with the motor running, the receiver is
cycled off for 9.5 msecs and on for 46 msecs. Once the motor stops,
whether due to a transmitted signal, or due the shade 106 reaching
either an upper or a lower travel limit, or an obstruction, the
receiver is shifted back into the look mode.
[0073] It should be noted that the above times are nominal values;
actual times may vary by as much as 25%, depending on what other
inputs the processor receives. It should also be noted that if the
receiver output is continuously low for a predetermined number of
cycles, e.g., 10 cycles, the receiver is considered to be in
saturation. In such case, the processor shifts the receiver to the
active mode to clear this situation.
[0074] In summary, then, the receiver 216 is switched between one
of two power cycle modes. Both transmitted signals and motor status
determine when the receiver is switched between the two modes. In a
given mode, the length of time for which the receiver is turned on
in each power-on, power-off cycle, is substantially the same. Also,
the length of time for which power is continuously connected to the
IR receiver 216 is independent of the content of the data received
during that connection period. Thus, even if a valid pulse is
received during a power-on period, power to receiver will be
disconnected at the end of that period. This differs from the
aforementioned U.S. Pat. No. 5,134,347 to Koleda, whose contents
are incorporated by reference in their entirety, wherein power to
the receiver is continued if a valid signal is received in the look
mode.
[0075] To activate the motor 122, four control lines 224 are
connected between the processor 214 and a bridge circuit 226. Two
of the four control lines are connected to base terminals of a pair
of NPN bipolar junction transistors (BJTs), each of which serves as
a switch to control one half of the bridge circuit 226. The
remaining two control lines are connected to the gate terminals of
a pair of low power field effect transistors (MOSFETs). Each of the
MOSFETs forms the lower portion of one half of the bridge circuit
226, allowing current to flow through its corresponding half when
that FET's gate is activated by the processor 214.
[0076] The circuit 210 includes a sensor subcircuit 228 which
gathers status information from one of three different sensors. The
microprocessor powers the sensor subcircuit 228 at predetermined
times through line IPWR, which is connected to resistor R3, and
reads the sensor output through line INP. To read a particular
sensor, it must first be enabled through a dedicated line DRV_CS,
DRV_LL and OPT_LED from the processor 214.
[0077] One of the three sensors is a channel select strap 230. The
channel select strap 230 allows a user to enable the processor 214
to match a received command signal only with stored sequences
corresponding to the selected channel. Preferably, the channel
select strap 230 can be accessed either from outside the head rail
or by simply opening its hinged front panel 114. The channel select
strap can be formed as a simple wire or a jumper connector
connecting two pins or leads. Alternatively, it can be formed as a
two-position switch, much like the channel selector 222 on the
transmitter 218. When the wire or jumper connector is intact, the
processor 214 will try to match received command signals with
stored sequences corresponding to channel A. And when the wire or
jumper connector is not in place, e.g, when the wire is cut or the
jumper connector is removed, the processor tries to match received
command signals with stored sequences corresponding to channel
B.
[0078] To determine which channel has been selected, the processor
214 powers the sensor subcircuit 228 using line IPWR, enables the
channel select strap using line DRV_CS, and reads the input on line
INP. In normal use, the channel selector strap 230 is only examined
(i.e., IPWR and DRV_CS are both activated and INP is monitored)
upon power start-up. As stated above, power start-up takes place
when the batteries are first connected or when the power switch is
activated, if a power switch is provided. Thereafter, if the
channel select strap 230 is altered to designate a different
channel, the processor 214 will continue to match received
sequences only against stored sequences corresponding to the
previous channel. Thus, after changing the channel select strap,
the power must first be turned off before the processor 214 will
recognize sequences corresponding to the newly directed
channel.
[0079] One skilled in the art will recognize that the channel
select strap 230 may be configured to allow one to select from
among more than two channels. This can be done, for instance, by
using a plurality of jumper connectors or a dip switch, or other
device, which allows only one channel to be designated at a time.
In such case, the processor 214 must connect an enable line,
similar to DRV_CS, to each of these channel selection connectors
and selectively activate them upon start-up. Alternatively, the
processor 214 may output a set of coded enable lines which are then
connected to a multiplexer, and from there to each of the channel
selection connectors. If a plurality of channels are provided, the
processor 214 must also store UP and DOWN sequences for each of
these channels, and these sequences must include enough pulses to
uniquely code for the chosen number of channels. Finally, the
transmitter 218 should be provided with a multi-position switch or
dial, allowing it to select from among the various channels and
output corresponding UP and DOWN sequences. Such a configuration
can allow a single transmitter to selectively control a plurality
of shades.
[0080] The second sensor monitored by the processor 214 is the lift
cord detector 146, discussed above. To determine whether the lift
cord 120' is abutting the lift cord detector 146, the processor 214
powers the sensor subcircuit 228 using line IPWR, enables the lift
cord detector 146 using line DRV_LL, and reads the input on line
INP. It should be noted that current to the motor does not flow
through the lift cord detector 146; only a current and voltage
sufficient to be detected by the processor 214 is necessary.
[0081] The third sensor monitored by the processor 214 is used to
count the number of interruptions made by the star wheel 198, and
thus indirectly count the number of revolutions that the drive
shaft 196 turns. As represented by the dashed line 234 from the
motor 122 to the sensor 232, motor rotation is indirectly coupled
to the sensor 232 in this manner. In the preferred embodiment, the
third sensor 232 is an electro-optic sensor 232, although a
magnetic sensor may also be used, as explained above. The
electro-optic sensor creates a light path which is interrupted by
the star wheel 198. The sensor 232 comprises a light emitting diode
LED1 and a phototransistor PT1. As the motor 122 turns, so does the
star wheel 198, and the interruptions of the star wheel affect the
output of the phototransistor PT1.
[0082] As explained above, the electro-optic sensor 232 operates
only when the motor is just about to run and continues to operate
so long as the motor is running. Thus, to activate the
electro-optic sensor 232, the processor powers the sensor
subcircuit using line IPWR, enables the light emitting diode LED1
using line OPT_LED and reads the input on line INP. Each time the
star wheel 198 interrupts the path between LED1 and PT1, this
interruption is sensed by the processor on line INP.
[0083] Thus, when the motor is just about to run, and also while
the motor is running, the processor 214 powers the sensor
subcircuit 228. It then periodically enables the cord detector 146
with line DRV_LL and reads the input on line INP, and also
periodically enables LED1 and reads the input on INP.
[0084] In this manner, the microprocessor monitors these sensors
with a single sensor input line. After power startup, only the lift
cord detector 146 and the optical sensor 232 are monitored. And
even these two are monitored only if the processor has been
directed to turn on the motor 122 asked to turn on by either the
transmitter 218 or by the manual switch 130.
[0085] FIG. 14 presents a circuit diagram of the power supply.
Power is supplied by the battery pack 150. Diode D3 provides
battery reversal protection. The power supply provides a 12 volt
source to drive the motor and a 5 volt source to drive the
remainder of the circuit. A voltage regulator U2, which has a
quiescent current of about 1 .mu.A, is always on, providing a 5
volt source. Capacitors C1 and C2 and resistor R1 filter motor
noise connected to the 12 volt supply. This prevents the motor
noise from affecting the voltage regulator U2. Capacitor C3
provides added power filtering. The values of the resistors and
capacitors for the entire circuit are presented in Table 1.
[0086] FIG. 15 shows input and output lines connected to the
processor 214. Resistor R2 and capacitor C5 from an oscillator at
nominally 2.05 MHz (plus or minus 25%). This provides an internal
timing clock for the processor.
[0087] FIG. 16 presents the circuitry of the interface module 128.
A 4-pin connector J3 on the interface module 128 communicates with
a 4-pin connector J3 on the PC-board. As explained above, the four
lines include an IR receiver power line IRPWR, an IR receiver
signal line IRSIG, which is active low, a ground connection shared
by both the manual switch 130 and the IR receiver 216 IRSIG, and
the manual switch output line MAN which is pulled high by pull-up
resistor R5, and is also active low.
1TABLE 1 Component Values COMPONENT VALUE C1 10 mF C2 10 mF C3 10
mF C5 22 pF C6 0.1 .mu.F R1 51 k.OMEGA. R2 10 k.OMEGA. R3 100
k.OMEGA. R4 300 k.OMEGA. R5 100 k.OMEGA. R6 1 k.OMEGA. R7 1
k.OMEGA. R8 1 k.OMEGA. R9 620 .OMEGA.
[0088] FIG. 17 shows a circuit diagram of the sensor subcircuit
228. To enable any of the sensors, the processor 214 must apply
power to the circuit by driving IPWR high (i.e., 5 volts) and
monitor line INP. The processor must also enable the sensor it
wishes to monitor by driving one of normally high OPT-LED, DRV_LL
and DRV_CS lines low (i.e., setting it to 0 volts).
[0089] To determine the state of the channel selector strap 230
upon power startup, the processor 214 drives IPWR high, drives
DRV_CS low (i.e., sets it to 0 volts) and monitors INP. If INP is
low, the channel selector switch is deemed to be intact, and so the
processor is informed that it should match incoming signals against
reference sequences for channel A. If, on the other hand, INP is
high, there is no continuity across the channel select strap 230,
and the processor knows to match for channel B.
[0090] To determine the state of the lift cord detector 146, the
processor again drives IPWR high, drives DRV_LL low, and monitors
INP. If INP is low, this indicates that the detector's reed 148 is
closed and so the lift cord 120' must be abutting the reed 148.
This will inform the processor that there is tension in the lift
cord 120' and that the shade is not at the bottom.
[0091] Finally, to activate the optical sensor 232, the processor
214 drives IPWR high, OPT-LED low, and monitors INP. This allows
current to flow through LED1, causing it to emit light. This light
is sensed by the phototransistor PT1, causing it to conduct and
voltage to drop across resistor R3. Thus, when PT1 conducts, line
INP is low. Each time the star wheel 198 interrupts the path
between LED1 and PT1, line INP temporarily goes high. The number of
times this line transitions from low to high and back to low is
counted by the processor 214, and this number is translated into
the number of rotations of the reel shaft 124 relative to some
starting point.
[0092] When the motor is energized, the optical sensor 232 and star
wheel 198 serve a second purpose. Each time the motor 122 is
activated, the processor 214 starts an internal stall timer, which
is formed as a register in memory. The stall timer times the
interruptions of the magnetic or optical path, as caused by the
spokes 200 of the star wheel 198. Each time an interruption occurs,
the stall timer is reset. If the stall timer times out, it means
that successive interruptions did not take place as quickly as they
should have, and so the drive shaft 196 (and hence, the motor 122)
did not turn as they should. This indicates a motor stall
condition, such as when the shade is fully closed and can go no
higher. Thus, whenever the motor 122 is running, the processor 214
checks for motor stall. If a stall is detected by the processor
214, it then no longer activates the motor 122, thus preventing
damage to electrical and mechanical components of the assembly
100.
[0093] FIG. 18 presents the circuit diagram of the H-bridge circuit
226. Four lines from the processor control the bridge. Lines HLP
and HRP control the H-bridge's left and right P-circuit,
respectively, and lines HLN and HRN control the H-bridge's left and
right N-circuit, respectively. As shown in FIG. 17, the P-circuit
controls the upper half of the H-bridge, and the N-circuit controls
the lower half of the H-bridge.
[0094] As shown in FIG. 18, lines HLP and HRP are connected to the
base leads of left and right NPN switching transistors Q1 and Q3,
through an associated current limiting resistor R6 or R8. When
either line HLP or line HRP is driven high by the processor 214,
the corresponding base-emitter junction on Q1 or Q3 is forward
biased, allowing current to flow through that transistor, assuming
other conditions are met. The collectors of Q1 and Q3 are connected
via resistors R7 and R9 to the base leads of associated respective
left Q2 and right Q4 PNP power transistors. The emitters of these
two power transistors, Q2 and Q4, are connected to the 12 volt
power supply, while their collectors are connected to separate
leads of a connector J5. Connector J5, in turn, is connected to
corresponding leads of the motor 122, allowing the latter to be
energized in either direction.
[0095] Lines HLN and HRN are connected to the gates of N-channel
MOSFETs Q5 and Q6, respectively. These lines are normally high when
the motor 122 is not activated, thus turning on the Q5, Q6. This is
the brake condition, which blocks current from passing from the
collectors of Q3 and Q4, through the MOSFETs and on to ground.
[0096] When the motor 122 is to be activated in a first direction,
HLP is driven high and HLN is driven low simultaneously. And, when
the motor is to be activated in a second direction, HRP is driven
high and HRN is driven low. In this manner, the bridge circuitry is
configured to activate the motor in either direction. While the
motor 122 is running, diodes D2 and D3 provide protection from back
electro-motive force (EMF) from the motor 122 and capacitor C6
filters some of the high frequency noise from the motor 122.
[0097] The operation of the window covering assembly 100 is
described next. As discussed above, the processor's RAM comprises a
number of storage locations which keep track of sensor and status
data. Among these storage locations are: a) a rotation counter, b)
an upper limit register, which keeps track of the upper limit to
which the shade may rise, c) a looking-for-upper-limit flag, which
keeps track of whether or not the processor should look for an
upper limit, d) a channel register, which keeps track of which
channel's reference sequences should be used for matching with the
received sequences, and e) a direction register, which keeps track
of the last direction of shade travel.
[0098] On power startup, the rotation counter and upper limit
counter are both set to a large, predetermined value, indicating
that there is no upper limit, and the looking-for-upper-limit flag
is set to not look for an upper limit. Also, the last direction
counter is set to up (so that if the manual switch 130 is pushed,
the shade will go down), and the channel register is set to A or B,
depending on the channel strap.
[0099] After these registers are initialized, the processor enters
a quiescent state in which the processor 214 first checks whether
the manual switch 130 has been pushed. If the manual switch 130 has
not been pushed, the processor next turns on the IR receiver 216
for 7.1 msec and then turns it off. If no valid pulse was received
within that period, the processor enters a sleep state for a
predetermined period of time, about 300 msecs. As it enters the
sleep state, the processor 214 makes sure that the transistors Q2
and Q4 are off, MOSFETs Q5 and Q6 are on (brake) and that all other
outputs and sensors are off. After waking up, the processor 214
loops through the quiescent state once again. If, during the
quiescent state, either the manual switch 130 is pushed or a valid
pulse is received, the processor 214 enters the active state.
[0100] In the active state, the processor 216 processes the input,
and takes any necessary action in response, such as activating the
motor 122. When the motor is running, the IR receiver is 216 is
placed in the active mode and the processor 216 checks IRSIG,
checks the lift cord detector 146, updates the rotation counter
with each interruption, and checks the stall timer, and the manual
switch 130.
[0101] At any given time, the shade 106 can be in one of three
positions: 1) shade fully up (open), 2) shade fully down (closed),
and 3) the shade partially down. Also, as stated above, the shade
can be activated by either a) the manual switch 130, or b) either
button 220a, 220b on the transmitter 218. This gives a total of six
combinations, or examples, to illustrate processor behavior, when
in the active state.
[0102] Example 1. Shade 106 fully up (open) and the manual switch
130 pushed. In this case, the lift cord detector 146 is abutted by
the cord 120', and so is closed. The processor 214 first checks the
direction register and determines in which direction the shade 106
last travelled.
[0103] Case 1a. Last direction of travel was "up". The appropriate
half of the bridge circuit is turned on, and, after an appropriate
delay to avoid a short circuit, the other half of the bridge
circuit is turned off. The motor is turned on and the shade goes
down. The shade will continue to travel downward until a) the lift
cord detector 146 is opened by rotating the cord 120' off the reed
148 when the shade reaches the bottom of its travel, b) the shade
encounters an obstacle, relieving tension in the cord 120' and
causing it to no longer abut the reed 148, c) the manual switch 120
is pushed a second time, or d) either transmitter button 220a, 220b
is pushed. Regardless of which of these events take place, the
direction register is toggled to indicate that the last direction
was "down", and motor and shade are stopped, after which the
processor enters the sleep state.
[0104] Case 1b. Last direction of travel was "down". The processor
will first check to see whether the shade is at the upper limit
(i.e., the value in the rotation counter matches that in the upper
limit register). If this is the case, the processor will ignore the
manual switch and enter the sleep state. If, for whatever reason,
the rotation counter indicates that upper limit has not been
reached, the processor 214 will activate the motor 122 to try to
force the shade up. As the shade will not go up, the stall timer
will immediately time out, causing the processor to deactivate the
motor. Following this, the direction register is toggled to
indicate that the last direction was "up", and the processor enters
the sleep state.
[0105] Example 2. Shade 106 fully up (closed) and a transmitter 218
button is pushed. Again, the lift cord detector 146 will be closed.
The processor 214 ignores the direction register and determines
which button was pushed.
[0106] Case 2a. Down button 220b is pushed. The shade will go down.
The processor and shade will behave in the same way as in Case 1a,
except that the shade will stop if either transmitter button 220a,
220b is pushed a second time.
[0107] Case 2b. Up button 220a is pushed. The processor and shade
will behave in the same way as in Case 1b. Again, the stall timer
will time out, causing the motor to stop, after which the processor
will toggle the direction register, and then enter the sleep
state.
[0108] Example 3. Shade 106 fully down (closed) and the manual
switch 130 pushed. In this case, the lift cord detector 146 will be
open, indicating that either the shade is fully lowered, or that
the shade is resting on an object. The processor 214 first checks
the direction register and determines in which direction the shade
106 last travelled.
[0109] Case 3a. Last direction of travel was "up". The processor
214 will determine that the lift cord detector is open. Because it
is open, the processor will not allow the shade to be lowered, and
so will enter the sleep state.
[0110] Case 3b. Last direction of travel was "down". The processor
will determine that the lift cord detector is open. This will cause
it to reset the rotation counter to zero, and enable the
looking-for-upper-limit flag so that, upon ascent, the processor
will compare the value in the rotation counter to the value in the
upper limit register. The processor will then activate the motor to
raise the shade. The shade will continue to travel upward until a)
the stall timer times out, indicating that the motor has stalled
(e.g., the shade is fully raised), b) the rotation counter reaches
the value in the upper limit register, c) the manual button is
pushed a second time, or d) either transmitter button 220a, 220b is
pushed. Regardless of which of these events take place, the
direction register is toggled to indicate that the last direction
was "up", and motor and shade are stopped, after which the
processor enters the sleep state.
[0111] Example 4. Shade 106 fully down (closed) and a transmitter
218 button is pushed. Again, the lift cord detector 146 will be
open, indicating that either the shade is fully lowered, or that
the shade is resting on an object. The processor 214 ignores the
direction register and determines which button was pushed.
[0112] Case 4a. Down button 220b is pushed. The processor 214 will
determine that the lift cord detector is open and so it will not
activate the motor to lower the shade. If the button 220b is pushed
for less than 3 seconds, nothing else happens and the processor
enters the sleep state. If, however, the button 220b is pushed for
3 seconds or longer, the upper limit counter is set to a large,
predetermined value, indicating that there is no upper limit. After
this, the processor enters the sleep state.
[0113] Case 4b. Up button 220a is pushed. The processor and shade
will behave in substantially the same way as in Case 3b, except
that the shade will stop if either transmitter button 220a, 220b is
pushed a second time. Additionally, however, if a stall is detected
when the shade is being raised from the lower limit, a new upper
limit will be set. For this, the upper limit register will be set
to 5 pulses less than the rotation counter, which has been reset to
zero just before the shade began to rise. The new upper limit value
will help ensure that the next time the shade is raised, (after
first having been lowered), the shade will stop at the new upper
limit, instead of continuing on and encountering a stall
condition.
[0114] Example 5. Shade 106 partially open and the manual switch
130 pushed. In this case, the lift cord detector 146 is abutted by
the cord 120', and so is closed. The processor 214 first checks the
direction register and determines in which direction the shade 106
last travelled.
[0115] Case 5a. Last direction of travel was "up". The shade will
go down until a) the lift cord detector 146 is opened by rotating
the cord 120' off the reed 148 when the shade reaches the bottom of
its travel, b) the shade encounters an obstacle, relieving tension
in the cord 120' and causing it to no longer abut the reed 148, c)
the manual switch 120 is pushed a second time, or d) either
transmitter button 220a, 220b is pushed. Regardless of which of
these events take place, the direction register is toggled to
indicate that the last direction was "down", and motor and shade
are stopped, after which the processor enters the sleep state. This
is similar to Case 1a.
[0116] Case 5b. Last direction of travel was "down". The processor
will first check to see whether the shade is at the upper limit
(i.e., the value in the rotation counter matches that in the upper
limit register). If this is the case, the processor will ignore the
manual switch and enter the sleep state. If the upper limit has not
been reached, the shade will go up until a) the stall timer times
out, indicating that the motor has stalled (e.g., the shade is
fully raised), b) the rotation counter reaches the value in the
upper limit register, c) the manual button is pushed a second time,
or d) either transmitter button 220a, 220b is pushed. Regardless of
which of these events take place, the direction register is toggled
to indicate that the last direction was "up", and motor and shade
are stopped, after which the processor enters the sleep state.
[0117] Example 6. Shade 106 partially open and a transmitter 218
button is pushed. Again, the lift cord detector 146 is abutted by
the cord 120', and so is closed. The processor ignores the
direction register and determines which button was pushed.
[0118] Case 6a. Down button 220b is pushed. The processor and shade
will behave in the same way as in Case 5a, except that the shade
will stop if either transmitter button 220a, 220b is pushed a
second time.
[0119] Case 6b. Up button 220a is pushed. The processor and shade
will behave in the same way as in Case 5b, except that the shade
will stop if either transmitter button 220a, 220b is pushed a
second time.
[0120] The processor 214 executes a series of software instructions
to control the window covering assembly. FIGS. 19 and 19-A to 19-J
present a flowchart which illustrates this software control.
Processor operation begins with powering up the system in step 300.
This is followed by step 302 in which various registers, counters
and flags are initialized, and the channel strap is read. Once this
initialization is finished, the processor enters the quiescent
state in which the processor looks for activity from either the
manual switch 130 or the IR receiver 216.
[0121] In step 304, the processor checks line MAN to see if the
manual switch has been pushed. If so, control flows to step 314 in
FIG. 19-A. If, however, the manual switch 130 has not been pushed,
the IR receiver is turned on for 7.1 msecs and then turned off in
the look mode (step 306). The processor then samples IRSIG to see
whether a valid pulse was received (step 308). If so, control flows
to step 316 in FIG. 19-B, If, however, no valid pulse was received,
the processor enters a sleep mode (step 308) in which it remains,
nominally, for 300 msecs before waking up (step 312). The processor
then continues in the quiescent state with control looping back to
step 304 to see if the manual switch 130 was pushed.
[0122] FIG. 19-A illustrates the control sequence when the manual
switch was pushed when the processor was in the quiescent state. In
step 314, the processor checks the direction register to see in
which direction the shade last was asked to move. If the last
direction was UP, it means that the shade should go down, and so
control flows to step 332 in FIG. 19-D. If, on the other hand, the
last direction was DOWN, the shade should now go up, and so control
flows to step 324 in FIG. 19-C.
[0123] FIG. 19-B illustrates the control sequence when a valid
pulse was received when the processor was in the quiescent state.
First, in step 316, the processor places the IR receiver 216 in the
active mode, discussed above. Next, in step 318, the processor
attempts to match the received sequence of pulses with the
reference sequences for the selected channel. If there is no match,
the processor enters the sleep state (step 310). If there is a
match, the processor determines which button on the transmitter, UP
or DOWN, was pushed (step 320). If the UP button was pushed,
control goes to step 324 in FIG. 19-C. If the DOWN button was
pushed, the processor checks to see whether the lift cord detector
reed is open (step 322). If the detector is not open, control goes
to step 322 in FIG. 19-D; if it is open (indicating that the shade
is either fully lowered or resting on an object), control goes to
step 334 in FIG. 19-E.
[0124] FIG. 19-C illustrates the control sequence when the
processor has been instructed by either the manual switch or the
transmitter to raise the shade. The processor first determines
whether the lift cord detector reed is open (i.e., whether the
shade is fully lowered or is resting on an object) (step 324). If
the detector is open, then the shade resets the rotation counter
and sets the looking-for-upper-limit flag (step 326), and then
turns on the motor to raise the shade (step 330). If the detector
is closed, the processor first checks whether the shade is at the
upper limit (step 328). If the shade is already at its upper limit,
the shade need not be raised, and so the processor goes to sleep
(step 310). On the other hand, if the shade is not already at its
upper limit, it can rise some more, and so the processor turns on
the motor to raise the shade (step 330). Whether or not the lift
reed was open, control goes to step 344 in FIG. 19-F, after the
motor starts.
[0125] FIG. 19-D illustrates the control sequence when the
processor has been instructed by either the manual switch or the
transmitter to lower the shade. The motor is simply turned on to
lower the shade (step 332), after which control passes to step 344
in FIG. 19-F.
[0126] FIG. 19-E illustrates the control sequence when the lift
cord detector reed is open and the down button on the transmitter
has been pushed. The processor first starts a 3-second timer (step
334), which is used to determine whether the down button is pressed
for the full three seconds. The IR receiver is maintained in the
active mode (step 336) and the processor checks the IRSIG line to
see whether the DOWN button is still being pressed (step 338). If
the DOWN button stops being pressed at any time within those three
seconds, the processor enters the sleep state (step 310), as the
shade cannot be lowered (since the lift cord detector reed is
open). The processor stays keeps checking the IRSIG line until
either the DOWN button is released or until the 3 seconds are over
(step 340), whichever occurs first. If the 3-second timer times
out, the upper limit counter is reset (step 342), and the processor
enters the sleep state (step 310).
[0127] FIG. 19-F illustrates the control sequence when the motor is
running, either up or down. With the motor running, the IR receiver
is in the active mode, the IRSIG and MAN lines from the interface
module 128 are monitored, the optical sensor 232, and the lift
detector reed 148 are polled, and the stall timer is operational
(step 344). The processor then executes a loop to check on all of
these.
[0128] When the IRSIG line is being monitored (step 346), control
flows to step 358 in FIG. 19-G. When the processor polls the lift
cord detector reed 148, it determines whether the reed is open
(step 348). If so, control goes to step 362 in FIG. 19-H. When the
processor polls the optical sensor (i.e, the phototransistor) it
determines whether the light path has been interrupted (step 350).
If so, control goes to step 366 in FIG. 19-I. If the stall timer
times out (step 352), control goes to step 372 in FIG. 19-J. And
when the MAN line is being monitored (step 354), the processor is
interested in knowing whether the manual switch 130 has been pushed
anew since the motor started running. If the manual switch has not
been pushed anew, the motor continues to run and the processor
continues to check the various inputs. If, however, it has been
pushed anew, the motor is stopped (step 356) and the processor
eventually enters the sleep state (step 310).
[0129] FIG. 19-G illustrates the control sequence when the motor is
running and the IR receiver is being monitored. The processor
checks to see if line IRSIG is active and if it is, whether either
transmitter button has been pushed anew since the motor started
running (step 358). If neither button has been pushed anew, the
motor continues to run and the processor continues to check the
various inputs. If, however, either button has been pushed anew,
the motor is stopped (step 360) and the processor eventually enters
the sleep state (step 310).
[0130] FIG. 19-H illustrates the control sequence when the motor is
running and the lift cord detector reed is opened. The processor
first checks to see whether the shade was going down when this
happened (step 362). If it was going down, the motor is stopped
(364), because the cord has fully unwound or because the shade
bumped into an obstacle on the way down. After the motor is
stopped, the processor enters the sleep state (step 310). If, on
the other hand, the shade was going up, the processor doesn't care,
and the motor continues to run and raise the shade.
[0131] FIG. 19-I illustrates the control sequence when the motor is
running and an interruption in the light path is detected. Whenever
the light path is interrupted, it means star wheel 198, and thus
the reel 124 are turning, the shade is either being raised or
lowered, and the motor is not stall condition. Thus, the processor
resets the stall timer and increments the rotation counter (step
366). The processor then compares the rotation counter to the value
in the upper limit register (step 368). If they do not match, it
means that the upper limit for the shade has not been met, and the
motor continues to run. If, on the other hand, they match, the
upper limit has been reached. In such case, the motor is stopped
(step 370), and the processor enters the sleep state (step
310).
[0132] FIG. 19-J illustrates the control sequence when the motor is
running and the stall timer times out. When this happens, it means
that the star wheel 198 and the reel 124 did not turn, even though
the motor was on, thus indicating a motor stall condition. A motor
stall can happen when the shade is all the way up and the rotation
counter does not match the value in the upper limit register. It
can also happen if the shade is held by an object which prevents
the former from rising. Other situations may also cause the timer
to time out. Regardless of what causes this, the motor is first
stopped (step 372). The processor then checks whether the rotation
counter was to stop when it reached the value in the upper limit
register (step 374). If so, the upper limit register is set to a
value slightly below the current rotation count (step 376). This
will prevent stall due to a spurious upper limit register value, on
a subsequent raising of the blind. After step 376 and also, in the
event that the rotation counter was not to be matched against the
upper limit register value, the processor enters the sleep state
(step 310).
[0133] While the above invention has been described with reference
to certain preferred embodiments, it should be kept in mind that
the scope of the present invention is not limited to these. One
skilled in the art may find variations of these preferred
embodiments which, nevertheless, fall within the spirit of the
present invention, whose scope is defined by the claims set forth
below.
* * * * *