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BACKGROUND OF THE INVENTION
This invention relates generally to infrared remote control systems and,
more particularly, to universal remote control units wherein one remote
control unit can control a number of various types of devices such as
televisions, video cassette recorders (VCRs), cable boxes, disk players
and other electronic equipment. The invention provides an improvement to
such universal remote control systems for enabling the devices and remote
control unit to be ready to communicate with each other.
Most manufacturers provide remote controls to control their equipment, and
equipment of different manufacturers are often controlled with different
remote control units. To minimize the number of individual remote control
units a user requires, universal remote control units have been developed.
Accordingly, infrared remote control units for controlling various
functions of television receivers, VCR's, and auxiliary electronic
equipment have become quite widespread in recent years. U.S. Pat. No.
5,255,313 issued to Darbee and assigned to Universal Electronics Inc., and
U.S. Pat. No. 5,552,917 issued to Darbee et al and assigned to Universal
Electronics Inc. disclose universal remote control systems.
In a common method of setting up and using a universal remote control unit,
infrared ("IR") function codes that are to be learned and used are made
available from the device to be controlled. The consumer or user is
required to program or adapt the universal remote control unit to control
the user's particular equipment, such as television sets, VCR's,
entertainment media, and other devices. Alternatively, codes can be
preprogrammed into the remote control to communicate with the equipment to
be controlled. In either case, the programming and adaption of the
universal remote control to the user's particular equipment can be
demanding, exacting and generally frustrating for many users.
SUMMARY OF THE INVENTION
This invention provides a universal remote control system wherein the
equipment to be controlled and the associated remote control unit are
preprogrammed and adapted to automatically configure or reconfigure the
remote control unit to communicate with the equipment to be controlled by
means of a bar code label, in other words, a label on the equipment to be
controlled is used to perform the setup of the remote control.
The foregoing features and advantages of the present invention will be
apparent from the following more particular description of the invention.
The accompanying drawings, listed hereinbelow, are useful in explaining
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of an inventive universal remote control unit with
bar code setup capability;
FIG. 2 is a sketch showing the inventive system wherein a remote control
unit provides controls to a TV set and VCR;
FIG. 3 is a circuit diagram (schematic) of the bar code reader circuit;
FIG. 4 is an example of the bar code;
FIG. 5 is a mechanical arrangement of an inventive universal remote control
unit with bar code setup capability; and
FIG. 6 is an updated flow chart of the inventive system.
DESCRIPTION OF THE INVENTION
The present invention relates to a universal remote control system with bar
code activated setup capability. As stated above, universal remote control
units are prevalent in the market place. Each of these remote control
units are used to control various types and brands of electronic devices
(equipment) in the consumer's or user's home such as the TV, the VCR,
cable box, disk player, etc. However, the prior art universal remote
control systems have to be programmed or adapted by the user to control
his particular equipment. Often this programming and adaptation becomes
quite difficult and frustrating to the user. As stated above, the present
invention is directed to providing a system wherein the devices to be
controlled and the remote control unit are readied to enter into
communication with each other by means of the user "swiping" the remote
control over a bar code label on the device, without requiring the user to
program or code in a set of commands; that is, the remote control unit can
be setup rapidly and with minimal effort on the part of the user.
FIG. 1 depicts the inventive system 11 wherein a universal remote control
unit with bar code activated setup (hereinafter "universal remote control
unit with BAS") capability 12 is positioned to control a TV set 14 and a
VCR 15. FIG. 2 shows the universal remote control device with BAS 12 in
more detail. The remote control 12 includes a microcontroller 19, an IR
transmitter and a photosensitive receiver arranged as shown in FIG. 5,
generally labeled as 20, various command keys generally labeled 16,
including a key for initiating setup of the unit, all as is well known.
A consumer or user will purchase a new VCR 15 labeled in accordance with
the invention to replace his old VCR 15 of any known brand. The inventive
universal remote control system 11 instructions will direct the user to
press a button or sequence of buttons on the remote control 12 (which will
cause it to energize the IR LED and the bar code detector circuit and
begin monitoring for valid bar code data) and then to swipe the remote
control 12 across the bar code label on the device, after which the
universal remote control unit 12 with BAS, which previously controlled the
old VCR 15, now controls new VCR 15. In the preferred embodiment, the user
initiates this state by pressing and holding a "setup" button for three
seconds until the visible LED on the remote control 12 blinks twice, as
shown in the flow chart of FIG. 6. However, it will be appreciated that
other mechanisms (e.g. entering a sequence of keys, flipping a switch,
etc.) may also be used to initiate said state. A VCR 15 is being referred
to herein for purposes of explanation, however, it is to be understood
that the invention relates to and is useful with a variety of other
electronic devices or equipment as referred to above.
To explain in more detail, the bar code label on the device contains a data
pattern which identifies:
a) the type of device it is; and
b) the remote control encoding format to which it responds.
If the microcontroller 19 of remote control unit 12 detects a recognizable
bar code pattern during the period the bar code reader circuit is enabled,
it proceeds to analyze the identification data. If the VCR 15 type and
requested IR format are supported by the remote control unit 12, the
microcontroller 19 reconfigures its programming to match the new VCR 15.
If the device or equipment is not supported by the remote control unit 12,
the remote control simply remains unchanged in its previous configuration.
In standard preprogrammed universal remote controls, the user selects a
transmission format by looking up a designation number for his device in a
code list supplied with the remote control, and enters that designation
number into the remote control. As becomes clear from the foregoing
explanation, a principal object of the inventive system is to simplify the
manner in which this designation number is communicated to the remote
control unit 12. Once the designation number has been supplied to the
remote control unit 12, the programming and mechanisms involved in this
set-up process are well known in the art and need not be described in
detail herein.
FIG. 5 shows the data frame layout. The data content of the bar code is a
32 bit value, utilized as shown in the following table:
8 bits System identification to allow possible future multiple versions
of the system to co-exist without interfering with one another's
settings.
4 bits Device category
00 TV 08 CD player
01 VCR 09 Amplifier
02 Cassette tape 10 Tuner
03 Laser disk 11 Home automation
04 Digital audio tape 12 Misc. audio
05 Cable box 13 Phonograph
06 Satellite IRD 14 DVD
07 Video Accessory 15 Spare
12 bits Device designation number, set-up code in the pre-programmed
library.
8 bits check byte (longitudinal parity of the preceding three bytes)
The data is encoded, most significant bit first, using bar code symbols as
described below.
FIG. 4 illustrates a 32-bit binary bar code-encoding example. Started from
the left hand side, there is a start guard pattern represented by two
extra-wide elements, then the 32-bit binary information follows the start
guard pattern. A stop guard pattern with an extra-wide element, followed
by a narrow element on the very right hand side concludes the bar code. A
logic "1" bit is encoded as a wide element, while a logic "0" bit is
encoded as a narrow element.
An extra-wide element is consisted of an extra-wide bar (3/16 in.) followed
by a narrow space (1/16 in.). A wide element is consisted of a wide bar
(1/8 in.) followed by a narrow space. The encoding scheme is a modified
version of the standard 3 of 9 code (also referred to as Code 39).
The 32-bit binary bar code-encoding example illustrated in FIG. 3 can be
scanned from two directions (right to left or left to right) and a proper
decoding scheme for the bar code scanner device can retrieve the binary
information from the bar code.
In the example shown, it can thus be seen that the bar code represents the
bit pattern 0100 0011 0100 1000 0100 0101 0100 1110 which according to the
above bit assignment represents system 43, device type 4, device number
845, with even longitudinal parity.
This encoding format is one implementation, but other encoding schemes can
be used to achieve the same result. In particular, a 32-bit number,
including 8 bits of system identification is used in this example to
maintain consistency of numbering with the device activated setup ("DAS")
referenced in a corresponding application. In practice, the bar code data
may be reduced to 24 bits or fewer with little negative impact in this
application.
The mechanism used to read this bar code is described in the following. The
IR emitting LED which is the same IR LED as is used during normal
operation of the remote lights the bar code, which absorbs the light or
reflects it back to a light-sensitive photodiode. A binary sequence of 1's
or 0's may thus be represented by the widths of a series of reflective or
non-reflective elements. The input signal to the bar code scanning
circuitry is the reflected IR light from the bar code when the IR emitting
LED illuminates the bar code. The output of the bar code scanning
circuitry is logic one (1) which represents a reflective surface (white
space) or logic zero (0) which represents a non-reflective surface (black
bar).
In FIG. 3, the bar code scanning circuitry is illustrated. The bar code
scanning circuitry comprises a photodiode D1 along with the parallel
resistor R8 as the IR receiver to receive the reflected IR signal from the
IR emitting LED D2. A reference voltage generator is formed with
operational amplifier U1A and a resistor divider consisted of R3 and R4. A
small gain amplifier is formed with U1B, R1 and R2. U1C, Q1, C1, R5, R6
and R7 form a maximum voltage detector. A voltage comparator is formed
with operational amplifier U1D. The power switching circuitry is formed by
transistor Q2 and resistor R9. The power switching circuitry is to turn on
or turn off the power supply for the bar code scanning circuitry, under
control of the microprocessor via the input signal labeled "Power Switch."
The operation of IR receiver is discussed below. Photodiode D1, together
with resistor R8 as the IR receiver, is connected to the input of the
small gain amplifier U1A. If the radiant intensity of the IR light to the
PN junction of the photodiode has greater energy than the silicon's energy
band gap of the photodiode, the electrons and holes diffuse in the PN
junction will cause an open circuit voltage across the PN junction.
Current flows through the junction in reverse direction if a load is
connected across it. The amplitude of the current flow is proportional to
the illuminance to the photodiode. Resistor R8 across D1 and the input
impedance of operational amplifier U1A serve as the load for the
photodiode. Resistor R8 reduces the total load resistance for the
photodiode thus improves the photodiode's response speed. Resistor R8 also
reduces the noise level to the input of the amplifier U1A.
The reference voltage generator is illustrated below. Operational amplifier
U1B, along with the voltage divider consisting R3 and R4, are used as a
reference voltage generator. The output of U1B is the reference voltage.
This reference voltage is a fixed voltage level which value is the
difference of the bar code scanning circuit's positive power supply Vcc
minus 1.5 divided by 2. This calculation is based on the fact that the
maximum output of the operational amplifier is 1.5 volt less than the
positive power supply and this reference voltage will allow the
operational amplifier to work in the small signal linear area. Assume that
the positive power supply Vcc is 5 volt, then the reference voltage will
be 1.7 volt. This reference voltage provides the virtual ground for the
input of the amplifier U1A and the virtual ground of the comparator U1D.
Comparator U1D will be discussed later. Notice that the cathode of the
photodiode is connected to the virtual ground. Using the virtual ground
instead of the actual ground allows amplifier U1A to work in the
amplifier's linear area thus reduces the distortion of the IR input signal
to the IR receiver.
The small gain amplifier U1A is discussed in the following. The ratio of
the feedback resistor R1 and resistor R2 determines the voltage gain of
the small gain amplifier U1A. As we have discussed above, the input signal
to the bar code scanning circuitry is the reflected IR light when the IR
emitting LED D2 scans the bar code. The input signal amplitude, in
general, is proportional to the illuminance to the photodiode. More
specifically, when the emitting IR LED lights the reflective surface
(space), the input voltage to amplifier U1A is high; when the emitting IR
LED lights the non-reflective surface (bar), the input voltage to
amplifier U1A is low. The amplitude of the input signal is small (in the
range of ten's of millivolt) and the amplifier U1A with the gain
approximately about 20 is necessary to assure that the input signal after
amplifier U1A has the amplitude about 1.5 v, and consequently, to assure
that the output of the bar code scanning circuitry is logic zero (0) when
scanning the bar code's reflective surface (space) or logic one (1) when
scanning the bar code's non-reflective surface (bar).
The operation of the maximum voltage detector is now described. The maximum
voltage detector consisted of operational amplifier U1C, transistor Q1,
capacitor C1, and a few resistors. The output of the amplifier U1A is fed
to the maximum voltage detector. The maximum voltage detector detects the
peak of the output of amplifier U1A by using the voltage follower U1C and
the charge-discharge circuitry consisted of Q1, C1, R5, R6 and R7. R5, R6
and R7 also serve as the voltage divider to provide the reference voltage
for the comparator U1D and will be discussed later. The positive input of
U1C is connected to the output of amplifier U1A. The negative input of U1C
is connected to the charge-up capacitor C1. Transistor Q1 provides the
current source for the charge-up capacitor C1. The discharge circuitry
comprises of C1, R5, R6 and R7.
When a peak signal appears (a signal transition from low to high) at the
output of amplifier U1A, capacitor C1 is quickly charged up to the signal
peak level because the current source from transistor Q1 provides
sufficient current for it. Notice that transistor Q1 is turned on when a
peak signal is detected at the positive input of U1C because the output of
U1C is connected to the base of the transistor Q1 and the negative input
of U1C is connected on the emitter of transistor Q1. Thus a signal
transition from low to high at the positive input of U1C causes transistor
Q1 to be turned on. A signal transition from high to low at the positive
input of U1C causes transistor Q1 to be turned off. On the other hand,
when a signal transition from high to low is detected at the positive
input of U1C, capacitor is discharged slowly because the discharge path is
provided through C1, R5, R6 and R7 and the discharge time constant is
about the range of 10 second. In this way, the voltage level of the
charge-up capacitor C1 always maintains the signal's peak level from the
output of amplifier U1A. The voltage level of the charge-up capacitor C1
is the output of the maximum voltage detector. Notice that the output of
amplifier U1A is also connected to the positive input of the comparator
U1D as the comparator's input voltage.
The configuration and operation of comparator U1D is described below. When
the voltage level at the positive input of U1D (V+(U1D)) is less than the
voltage level at the negative input of UlD (V-(U1D)), the output voltage
of U1D is low or logic zero (0). On the other hand, when V+(U1D) is higher
than V-(U1D), the output voltage is high or logic one (1). As have
discussed in the reference voltage generator session above, the reference
voltage generator provides the virtual ground of about 1.7 volt for the
comparator U1D. R5, R6 and R7 are served as the voltage divider to provide
the reference voltage for the comparator U1D. The middle point of this
voltage divider is the reference voltage and is connected to the negative
input of comparator U1D. This provides the reference voltage. The ratio of
this reference voltage level to the voltage level of the charge-up
capacitor C1 is determined by the ratio of the average voltage level
between output high of amplifier U1A (when the scanner lights the
reflective surface (space)) and output low of amplifier U1A (when the
scanner lights the non-reflective surface (bar)) to the voltage level of
output high of amplifier U1A. This ratio is about seventy-six percent.
This means that assume that the output high for amplifier U1A is 1.0 volt,
the output low for amplifier U1A is 0.52 volt, and the average voltage
level between output high and output low of amplifier U1A will be 0.76
volt and this ratio number of seventy-six percent is used to determine the
ratio of the value of resistor R6 to the value of resistor R6 plus the
value of the parallel of resistor R5 and R7.
In particular, the configuration and operation of comparator U1D is to
assure that the comparator is working as a virtual zero-crossing detector
where the virtual zero voltage is provided by the reference voltage which
is the middle point of the voltage divider comprising of R5, R7 and R6.
When the positive input of the comparator U1D higher than the virtual zero
voltage, the output of the comparator is logic one (1). When the positive
input of the comparator U1D lower than the virtual zero voltage, the
output of the comparator is logic zero (0). Notice that the positive input
or the input of comparator U1D is connected to the output of the small
gain amplifier U1A. Further more, the configuration and operation of
comparator U1D is also to assure that when the bar code scanner device
with this bar code scanning circuitry scans at the reflected surface
(space), the device's output will be logic one (1). When the device scans
at the non-reflected surface (bar), the device's output will be logic zero
(0).
The IR emitting circuitry is illustrated in FIG. 2 and is formed by the IR
emitting LED D2, transistor Q3 and resistor R22. The IR emitting circuitry
illuminates the bar code for photodiode D1. The IR emitting circuitry is
already a part of the regular Universal Remote Control and is shown here
for clarify only. Transistor Q3 is used as the switch to turn on or turn
off the IR emitting circuitry, under control of the microprocessor via the
input signal "IR emitter on/off."
It is also important to note that the bar code may be located other than on
the device itself: it may for example appear on the carton in which the
device is packaged, or in the user manual supplied with the device, or
even in the user manual supplied with the remote control.
While the invention has been particularly shown and described with
reference to a particular embodiment thereof it will be understood by
those skilled in the art that various changes in form and detail may be
made therein without departing from the spirit and scope of the invention.
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