Note: Descriptions are shown in the official language in which they were submitted.
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REMOTE CONTROL UNIT
This invention relates to a remote control unit for use with an air
conditioning
apparatus. The invention also relates to a control system for an air
conditioning
apparatus which is adapted to respond to signals from a remote control unit.
The remote controller has become an everyday object, indispensable for
operation of
the TV, video recorder and hi-fi. More recently, remote controllers have been
provided for controlling the operation of an air conditioning apparatus. The
apparatus
may be of the wall-mounted or window-inounted type found in most homes or the
ceiling-mounted type commonly used in commercial and industrial properties.
The number of functions of the air conditioner which it is desirable to
control remotely
is many. These range from the basic on/off operation and temperature setting
to the
more sophisticated adjustment of a timer to switch the apparatus on and/or off
at preset
times. As a result of these requirements, the conventional remote control unit
has a lot
of buttons and switches to be operated and is not user-friendly.
A further problem arises in the home when one wishes to change a setting while
in bed,
for example after having been woken up prematurely due to excessive heat or
cold. It
is not easy to operate the unit in the dark, yet one is reluctant to switch on
the light at
such a time.
Finally, as compared with changing channels on the TV, it is sometimes
difficult to be
sure that the air conditioner has responded properly to a signal sent from the
remote
controller.
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In its various aspects, the invention aims to overome the above problems by
providing
user-friendly remote control of the air conditioner.
In one aspect, the invention provides a remote control unit adapted for use
with an air
conditioning apparatus, the unit comprising display means for generating a
display
representing a plurality of functions to be controlled, and user-operable
control means
for selecting and setting a desired function, wherein the user-operable
control means is
shared by the plurality of functions.
According to this aspect of the invention, the remote control unit can be made
user-
friendly by reducing the number of buttons thereon. For example, it is
possible to
provide a master control button for use in selecting and setting all the
controlled
functions, thereby simplifying the design and use of the remote control unit.
In a
preferred embodiment, the selection of a function to be controlled is made
using a
cursor on the display. The cursor is moved up or down on the display using the
master
control button until it appears next to an icon representing the desired
function. The
master control button is then operated to adjust the selected function as
desired.
Another preferred feature resides in the division of the display into a
plurality of
selectively displayable screens, i.e. pages, the different screens
representing different
groups of functions. The choice of screen is suitably offered as an additional
selectable
function, which is displayed on each screen. The principal advantage of
dividing the
display into two or more screens is that the screen display presented to the
user is more
simple and less cluttered. The remote control unit is thus easier to use.
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In a preferred embodiment, there are two such screens. The first screen
includes those
functions which are more commonly changed, for example the temperature and fan
speed settings. The second screen includes those functions which are less
commonly
changed, for example the selection of cool, dry or fan mode of operation. The
first
screen is displayed as a default. That is to say, the second screen is
displayed only
when selected and the first screen returns when the master control button has
not been
operated for a predetermined period of time.
Although different functions are shown in the two screens, it is useful to
provide in the
first screen a display of a second screen function setting, when that setting
differs from
the normal or default one. In this way, the display provides a relatively
complete
picture of all the function settings of the air conditioner. Certain features,
such as the
time clock, are suitably displayed continously, irrespective of which screen
is selected
at any one time.
In another aspect, the invention provides a remote control unit adapted for
use with an
air conditioning apparatus, the unit comprising a display means, a user-
operable control
means, and means for illuminating the display means when the control means is
operated. The display is preferably also lit up when the unit is first
switched on.
According to this aspect of the invention, the remote control unit is easy to
use even in
the dark or in conditions of poor light. If this feature of a night light is
provided on the
remote control unit of the first aspect of the invention, the result is a
device which is
particularly easy to use since there need only be one main control button
other than the
on/off switcll.
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As a preferred feature, the night light operates only between preset times
which are set
internally by the unit. In this way, the automatic operation of the display
light every
time the control button is pressed does not run down the batteries at times
when the
display will not need to be illuminated.
In a further aspect, the invention provides a control system for an air
conditioning
apparatus having a plurality of functions which are controllable by means of a
remote
control unit, wherein the control system comprises means for generating an
audible
signal whose characteristic sound depends on the function being controlled.
This feature assists the user by confirming that a command sent by the remote
control
unit to the air conditioning apparatus has not only been received, but is the
desired
command.
In one embodiment, the air conditioning apparatus has a function in which the
speed of
a fan may be set to one of a plurality of levels using the remote control
unit. The
generating means produces such an audible signal when the fan speed setting is
changed, the audible signal being different for each respective setting.
According to this embodiment of the invention, the setting of the fan speed is
easily and
conveniently confirmed by the user. The audible signal may be a tone signal
whose
pitch depends on the fan speed setting.
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The invention is illustrated, but not limited, by the following description of
an
embodiment given by way of example only with reference to the accompanying
drawings, in which:
Fig. 1 is an overall view of a remote control unit;
Fig. 2 is a representation of the display of the unit;
Fig. 3 is a schematic representation of the controls of the unit;
Figs. 4 and 5 respectively show examples of two screens of the display;
Fig. 6 is a block diagram for the remote control unit;
Fig. 7 is a simplified circuit diagram for the remote control unit; and
Fig. 8 is a block diagram for the receiver/control circuity of an air
conditioning
apparatus.
Referring first to Figs. 1 to 3, the remote control unit includes a moulded
plastic body
10, an on/off switch 12, a master control button 14 and a display device 16.
The on/off switch 12 is operated to switch the air conditioner on and off
remotely. The
operation of the switch 12 also activates and de-activates the display shown
on the
display device 16, apart from certain parts of the display which remain active
even
when the air conditioner is switched off.
The master control button 14 is used to select and set the desired functions
of the air
conditioner. It is used in conjunction with the display. The master control
button 14
consists of a rocker-mounted member which carries movable contacts. The button
14
can be manipulated to operate any of four switches at any one time by pressing
on one
of the four arrows 14a-14d. The button 14 returns to its neutral position upon
release.
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The upper and lower arrows 14c, 14d are used to select a function which it is
desired to
switch on or off or adjust. This is done by moving a cursor which appears in
the
display as a triangular arrow. The left and right arrows 14a, 14b are used to
set the
function after it has been selected.
The display device 16 is a liquid crystal display (LCD) which has a fixed
pattern of
display electrodes. Use of a display device of this general type is preferred
over a dot-
matrix type of device since the drive circuitry is simpler and the cost is
lower. The
same device can be used for a number of models of air conditioner. For any
functions which are not provided on a particular. model, the related parts of
the display
may be left unconnected or arranged so as not to be driven by the control
electronics.
Fig. 2 shows the complete set of display electrode patterns (apart from the
two clock
displays and the temperature setting which illustrate sample readings). In use
of the
unit, this complete set of patterns will never be seen and the display
presented at any
one time will be clear and easy to read.
The uppermost part of the display contains a real-time digital clock which is
shown
continuously, and a transmission symbol which appears momentarily whenever a
signal
is transmitted by the remote control unit to the main air conditioner unit. In
the bottom
right of the display, a battery symbol appears when the batteries of the
remote unit need
replacing. The remainder of the display is given over to the clioice of
functions.
These are, in descending order, the temperature setting, sleep mode, fan
speed,
principal mode of air conditioning, flap control for adjusting the direction
of the fanned
air, timer control and screen selection function. The latter function will be
described
later with reference to Figs. 4 and 5. For now, the remotely controllable
functions of
the air conditioner will be considered.
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Each of the functions is represented by an icon which appears to the left of
the display.
The status or setting of each function is represented by an associated icon
presented to
the right of the display and adjacent to the related function icon. As used in
this
specification, the term "icon" refers to a graphic symbol or an alphanumeric
expression, or a combination of both. Each function has a default setting
which is
automatically programmed when the batteries are first put in the unit or later
replaced.
The temperature control allows the thermostat to be set for a room temperature
in the
range 18 to 30 C, adjustable in steps of 1 C. The set temperature is displayed
whenever the air conditioner is in operation, except in the fan only mode. The
set
temperature may be raised by pressing the right-hand (+) arrow 14b of the
control
button and lowered by pressing the left-hand (-) arrow 14a thereof. The
default setting
is a temperature of 23 C.
In the sleep mode, the set temperature is automatically raised by 2 C to
provide
comfortable cooling and save energy during sleeping hours. The mode is
switched on
or off using the left and right arrow keys of the master control button. The
sleep mode
is also automatically switched off one hour after activation. The default
setting
switches the sleep mode off.
The fan speed settings are low, medium, high and automatic. The adjustment is
made
using the left and right keys of the master control button. In each of the
low, medium
and high settings, a respective icon is shown on the display. In the automatic
mode, all
three icons for low, medium and high appear simultaneously. The default
setting is for
automatic control of the fan speed.
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The air conditioning modes of operation are cool, dry, fan and, optionally,
heat. The
mode selection is again made using the left and right keys of the master
control until the
required icon appears in the display. The default setting is for the cool
mode.
The flap control function permits the flap to be moved remotely using a
stepper motor
in the air conditioning unit, thereby adjusting the direction of the air flow.
The motor
is switched on and off using either the left or right keys of the master
control. When
the motor is switched on, the flap will move continously until an off signal
is
transmitted, changing direction at the end of the swing. In the default
setting, the
motor is naturally switched off.
The timer enables the air conditioner to be switched on and/or off at preset
times each
day. The start time is set by moving the cursor until it is opposite the start
icon and
then manipulating the left or right key to change the time display. The time
can be set
in increments of 10 minutes. The stop time is set in a similar manner after
moving the
cursor to a position opposite the stop icon. A clock symbol appears next to
the start
icon when the start time is displayed and next to the stop icon when the stop
time is
displayed. The timer function is inactive in the default setting. The unit
clock at the
top of the display must be set before the timer can be used. The unit clock is
adjusted
in the same manner as the timer settings.
Referring to Figs. 4 and 5, the operation of the remote control unit is made
more user-
friendly by dividing the display into two individually displayable screens.
Fig. 4 shows
the display of a first screen A, while Fig. 5 shows the display of a second
screen B.
Screen A presents the temperature, fan speed and flap motor functions. The
default
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settings of these functions are shown in Fig. 4. Screen B presents the sleep,
mode and
timer functions. The default settings of these functions are shown in Fig. 5.
The real-
time clock is shown in both screen A and screen B. Also shown in both screens
is an
additional function for selecting the required screen.
The first screen A contains functions which the user will more commonly wish
to
change. For this reason, screen A appears whenever the unit is first switched
on and is
thus presented as the default screen. The second screen B contains functions
which the
user will less commonly wish to change. To select and adjust one of those
functions,
screen B must first be selected. This is done by moving the cursor shown in
screen A
to a position adjacent to screen B icon and then pressing the left or right
key of the
master control button. When in screen B, screen A can be selected in a similar
manner
by moving the cursor next to the screen A icon. However, the display will
revert
automatically to screen A if the master control button is not operated for a
predetermined time. In this embodiment, a time lapse of 10 seconds is
provided.
Although displayed in both screens, the real-time clock can only be set in
screen B.
This is an adjustment that rarely needs to be made.
If a screen B function is changed to a setting or status which is other than
the default
setting or status, the icons for that function and its setting/status will
appear in
screen A. That function can then be selected and changed in screen A. If the
function
is later changed back to the default setting status, its icons will disappear
from
screen A. The function then has to be accessed via screen B. For example, if
the sleep
mode is switched on using screen B, the word SLEEP and the star-in-a-circle
icon will
appear in screen A, along with the usual icons for the temperature, fan speed
and flap
control. The sleep mode can now be switched off, i.e. to the default status,
in
screen A. Once the sleep mode has been switched off, the selected icons will
be
removed from screen A.
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Fig. 6 is a block diagram and Fig. 7 is a circuit diagram of the electronics
of the
remote control unit. All of the electronic components including the switches
12, 14 and
display device 16 are mounted on a single circuit board housed in the casing
10.
A micro-controller 18 in the form of an integrated circuit forms the heart of
the
electronics. The micro-controller 18 operates in response to actuation of the
on-off
switch 20 and the four control switches 22, 24, 26, 28 via the button 12 and
the four
arrow keys 14a-d of the master control 14. The remote control unit has a 3-
volt power
supply 30 provided by two pen cell-size batteries 32 contained within the
casing. The
micro-controller 18 is programmed to generate the drive signals for the
display device
16 and a control signal for transmission to the main air conditioning unit.
The control
signal is transmitted by infra red from an LED 34 following amplification in a
drive
circuit 36. The infra red LED 34 is located behind a lens (not shown) mounted
in the
uppermost edge of the unit, that is near the top of the display 16.
The programming of the micro-controller 18 to realise the functions described
herein is
within the ability of the ordinary skilled person in the art. The programmed
features
may be incorporated in a programmable read-only memory (PROM) contained within
the chip. Alternatively, the programmed features may be physically
incorporated into
the chip 18 at the time of its manufacture by semiconductor masking
techniques.
An infra red control signal is transmitted by the remote unit every time the
left or right
control key 14a, 14b is released, preferably after a short delay of, say, 0.5
seconds.
Thus, a control signal is transmitted every time a function setting is
changed.
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However, if one of the keys 14a, 14b is held down continuously, for example to
sweep
through a range of temperature settings, the signal will not be transmitted
until the key
has been released. A control signal is also sent when the unit is switched on
using the
button 12. No control signal is generated when merely moving the cursor to
select a
function or to switch between the screens A and B.
The control signal transmitted on each occasion is coded so as to contain the
status of
all settings of the remote unit, including the real-time clock. This ensures
that the
operation of the air conditioner conforms to what is expected from the
settings revealed
to the user on the remote display. Thus, if a setting is changed on the remote
unit but
the transmitted signal is not received by the main unit (for example, because
the remote
was not pointed to the main unit when transmitting), the main unit will be
updated the
next time the remote unit is operated.
In order to assist the user in operating the remote unit at night or in
conditions of poor
light, the LCD display 16 is provided with a light. In this embodiment, the
light
consists of a pair of LEDs 38 arranged adjacent the top edge of the display
panel. The
LEDs 38 are energised to light up the display whenever the master control
button is
manipulated or the switch 12 is operated to switch the unit on. The LEDs
remain on
for a predetermined time lapse after the last operation of any of those
buttons. In this
embodiment, the time lapse is about 10 seconds. It may also be arranged for
the
display light to be activated when master control is operated, eveii if the
unit is
switclied off. This will enable the user to clleck the tiine at night using
the real-time
clock display at the top of the LCD display.
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In this embodiment, the display light 38 only comes on between predetermined
on and
off times, which are measured with respect to the reading of the internal real-
time
clock. Since the activation of the light is made in response to the operation
of any of
the switches 20 - 28, the light control signal output by the micro-controller
18 can be
disabled at times outside of the operating hours, by suitable programming of
the chip
18. The on and off times may be preprogrammed in manufacture, or programmable
by
the user in a similar manner to setting up the main unit timer operation. The
preferred
operating hours are from 2000 (8 pm) to 0800 (8 am). The light control signal
output
by the micro-controller 18 switches on the LEDs 38 through drive circuitry 40.
Fig. 8 is block diagram of the infra red receiver and control system of an air
conditioner which receives transmissions from the remote control unit. At the
heart of
the system there is again a micro-controller in the form of an integrated
circuit 42. The
micro-controller is programmed to perform the functions described herein in
the same
manner as mentioned above in relation to its counterpart chip 18 in the remote
unit.
The required programming is within the ability of the ordinary skilled person
in the art.
The integrated circuit 42 incorporates a non-volatile memory which registers
the
various function settings. This is useful for when the power supply to the
main
unit fails or is otherwise interrupted. The memory enables the air
conditioning wlit to
be restored to its previous operating state, even wllen switched back on
manually, i.e.
without using the remote unit.
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The micro-controller 42 receives input signals from an infra red sensor 44
which picks
up the transmission from the remote unit, and, via an analog-to-digital
converter 46,
from sensors 48 which measure the indoor air temperature and the indoor fan
coil
temperature. In response to these input signals, the micro-controller 42
generates
output signals for controlling an LED display 50, the stepper motor 58 for the
flap
movement, relays 56 for controlling the fan motor and its speed and the
compressor,
and an audible signal generator 60. The generator 60 is suitably a miniature
buzzer of
the piezo-electric type.
A power supply 52 provides a low voltage 5V supply to the micro=controller 42
and the
converter 46, and a 12V supply for the relays 56, motor 58 and audible signal
generator 60 via driver circuitry 54.
The display 50 consists of two LEDs, suitably of different colour, one showing
the
power on status of the air conditioner, the other showing that the timer
function is in
operation.
In conventional air conditioners, the buzzer 60 is arranged to emit a short
"beep" in
response to every signal received from the remote control unit. While this
confirms
reception of the signal, it does not guarantee to the user that a required
function has
been set as desired.
In accordance with this embodiinent of the receiver/control system, it is
arranged that
the buzzer 60 emits different sounds for each setting of the fan speed.
Specifically, the
low, medium and high fan speed settings are distinguished by respective beeps
of
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different, here higher, pitch or tone. This function is conveniently set up by
programming of the micro-controller 42. The audio frequency of the buzzer
output
depends on the frequency of the input signal. Thus, the micro-controller 42 is
programmed to generate an output signal of a first frequency when the low fan
speed is
selected, a second frequency higher than the first one for the medium speed,
and a third
frequency higher than the second one for the high speed. There can also be a
fourth
signal of a frequency different to the other three to identify the auto
setting of the
fan speed. In this way, the set fan speed can be readily confirmed by the
user.
It will be appreciated that the above principle of generating distinctive
audible signals
can be extended to distinguish between different functions to be controlled.
Thus, there
may be one type of signal for, say, fan speed control and another type of
signal for,
say, timer operation. There are also many other ways of generating the
required
different sounds. These include varying the duration of the beep, varying the
number
of a series of beeps emitted in succession as a single signal, and varying the
speed
of succession of such a series of beeps, plus any combination of all these
characteristics.
The invention may be embodied in many other ways than those specifically
described
herein without departure from the scope thereof. The following variants are
noted by
way of example only.
It is not essential to divide the display into screens, since all the
functions could be
made selectable and settable from a single page of display. When the display
is
divided, there may be more than two screens. There may even be provided an
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individual screen for each function. The master control button 14 may be
replaced by
four separate push-buttons corresponding to the respective switches 22, 24, 26
and 28.
Alternatively, there could be one rocker-type button for operating the up and
down
switches 26 and 28, and another such button for operating the left (-) and
right (+)
switches 22 and 24. The display light feature can be applied to a conventional
air
conditioner remote control unit which has separate control buttons for the
different
functions.
