Note: Descriptions are shown in the official language in which they were submitted.
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D I SPL~Y DEVI CE
This pocketable display device for displaying
characters or graphic images received by radio. It relates
particularly, but not exclusively to non-alphanumeric
(English) languages, i.e general pictographic, written
languages including Oriental languages such as the Chinese
language and to a radio paging device for use with such
languages.
It is known to be extremely difficult to implement a
pager receiver for pictographic Oriental languages for the
following two reasons:-
a) Most Oriental languages have a huge number of
characters or pictograms as compared to English style
European languages. In particular, the Chinese language is
composed of more than 50,000 different characters.
Therefore, without the invention of a' special storage
technique, it would be impossible to accommodate such a
large vocabulary in any form of storage device which would
enable the pager to have a size comparable with the size of
a pack of 20 cigarettes. This is essential for a pocket
radio pager receiver.
b) ` NormaLly, longer air-tirne (which is a valuable
factor in the paging business) is required to transmit a
character of an Oriental language than a usual alphanumeric
character due to the larga number of characters which
require a longer code to identify individual characters.
Unless a special message recognition technique can be
devised and built into the radio pager receiver, an Oriental
language radio pager receiver will be too expensive ln terms
of running cost for its air-time message transmission.
~ t present, there are, of course, numerous radio pager
receivers which can provide the user with information in
English and alphanumeric characters. There still does not
exist a radio pager receiver which can receive~ and dlsplay
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the Oriental languages; in particular for the Chinese lanyuage by
overeoming the above mentioned problems. The usefulness and
attractiveness of information display pagers would be enhanced
considerably by the provision of a pager, capable of displaying
greater amount of information to the users in different Oriental
languages especially in the most popular Chinese languacJe.
A further problem with current pagers is that they have
an "Identification Code" (ID) which has been written and fixed
permanently into a piece of Read Only Memory, called a code plug
to enable the paging company to address indivldual pager receiver.
It would be much more cost effective and convenient to have a
pager which uses no code plug hut another innovative concept to
signify its own identification. At the moment, any change of the
; pager number ~ie ID) requires the replacement of a physical code
plug, which may involve the pager being taken back to the paging
station physically.
According to a first aspect of the invention, there is
provided a device for displaying graphical images, comprising:
(a) receiver means for receiving radio messages
containing at least one of (1) encoded graphical information,
which may include character font information, to be displayed, and
(2) command data;
(b) fixed memory means for storing fixed graphical
images, which may include character font images, at addressable
locations;
(c) volatile memory means for changeably storing
graphieal images/ which may inelude charaeter font images, at
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addressable locations~,
~ d) processor means, ~onnected to said r2ceiver means,
for processing the radio messages received from said receiver
means, said processor means including:
(1~ means for converting encoded graphical
information into 2N possible address codes each having N bits;
(2) means for addressing said fixed memory means
and said volatile memory means with said address codes to retrieve
graphical images therefrom and for using at least one of the 2N
possible address codes to select between addressing o~ said fixed
memory means and addressing of said volatile memory means; and
(3) means for altering the graphical images stored
; in said volatile memory means in response to command data received
by said receiver means, whereby the total number of graphical
images that may be retrieved from said fixed memory means and said
volatile memory by the 2N possible address codes exceeds 2N; and
(e) display means connected to said processing means
for displaylng the graphical images retrieved from said fixed
memory means and said volatile memory means by said addressing
means.
A device for displaying graphical images, comprising,
(a) receiver means for receiviny radio messages containiny
at least one of (1~ graphical information, which may include
character font information, to be displayed, and (23 command data;
(b) display means for displaying graphical i~ages, which may
include character font images, corresponding to graphical
information received by said receiver means,
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(c) volatile memory means for changeably storing an
identifying code identifying said device; and
(d) processor means connected to said receiver means, fox
precessing radio message received from said receiver means, said
processor means including;
(1) means for converting encoded graphical information
into graphical images for display by said display means, and
(2) means responsive to command da~a received by said
receiver means for altering ~he identifying code identifying said
device and stored in saicl volatile memory means.
These aspects of the invention are applicable to a
display device, particularly a radio paging device independently
of one another or in combination with one another.
As will become apparent from the following description,
the two aspects of the invention may be used to solve the above
mentioned problems, and when used together, may provide a pager
which can receive and display any type of Oriental languages, in
par~icular, the Chinese language and which requires no code plug
but yet can still be addressed by the paging company individually.
By using a custom made "Single Chip Microprocessor Application
Specific Integrated Circuit (ASIC)" controller loaded with a
special designed software program, the radio pager receiver can
have the capability to store the message data collected by an
electrcnics data reception module via a radio frequency channel
into a random access memory device - RAM, and at the
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same time through searching from a character fonts table
residing partly in a character generation read only memory
- ROM and partly in a read/write memory - RAM by executing
an innovative floating storage technique (to be described
later) to display the message received on a graphic LCD
module and a dynamic identification ~to be described later)
concept to identify a particular pager receiver among all
receivers.
The radio pager receiver itself can store up multiple
messages for the user to examine later. The control means
of the pager can be arranged to enable the displayed
messages to be viewed one by one either in the forward or
reverse directions and when it reaches the end, it will
display the first message again, the second message and so
forth again. It also enables each message, if too long, to
be displayed frame by frame (ie one display's worth at a
time). The user can also select mes~ages to be deleted from
the memory. The control means can also enable the user to
switch on/off the LCD display background lighting, and
switch off the audio tone upon receipt of a message.
The first aspect of the invention enables
implementation of the above mentioned floating storage
technique (FST) which is an innovative idea by using an
optimum number of bits to address a unique entry from a
fixed size character fonts table which has the capability to
cover an unlimited number of characters or pictograms. This
can be explained as follows:-
Let it be assumed that 'IN'' bits are used to representan address code representing one character of, for example,
an Oriental language. An N-bit code can normally address a
maximum of "2 to the power N" entries, each code
corresponding to a respective character. The FST involves
different usages of the 2N total number of available codes
along the lines of the following, In particular, it may
divide the 2~ codes into 4 usages:
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Usage 1 "X" combinations to address "X" fixed
entries with a character
font table residing in
read only memory (ROM).
; 5 Usage 2 "Y" combinations to address "Y" fixed
entries with the
- character font table
residing in RAM which can
be altered via the system
controller through
receiving a command from
the radio frequency
channel.
Usage 3 "z" combinations to address "phrases"
composed of a number of
pointers to cascade a
`................................................ s,equence of single
character entries within
the fixed vocabulary Erom
: 20 table "X" and "Y". These
pointer sequences are
. . located also in RAM which
can be altered by the
system controller through
receipt of a command from
the radio frequency
channel.
Usage 4 "1" combinations in case the required
character Eont does not
exist in the "X" and "Y"
.-. table or the display of
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some graphic is required,
this specific address
code can instruct the
system to construct the
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required graphic or
character fonts from the
direct bit pattern data
received from the radio
fre~uency channel; the
end of the bit pattern
can be indicated in any
~ suitable way, eg, by a
bit pattern following it
(such as the bit pattern
indicating the start of
usage 4) or by a preamble
which indicates the
lengths, width and
coordinates of the image
being sent.
It is obvious that the sum of "~", "Y", "Z" and 1 will
still equal to 2N. However, this technique offers the
following unique advantages over other methods being used:-
- Usage 1 can be used to hold the most frequently
used characters/pictograms, in the language in
question for efficient and fast processing and
translation.
- Usage 2 can be used to expand the system's
capability to recognise the whole
character/pictogram set of that particular
language without any pre-set limit.
- USage 3 enables the use of just "N" bits to
represent a frequently used phrase which might
comprise a string of any length of characters or
pictograms. This represents a considerable saving
of data space and licence ~ransmission time; the
transmission ~ime for message ~ransmission is the
most expensive and important element in the paging
industry.
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- Usage 4 further expands the system to recognise
information more than text messages, but to any
form of graphic information. In the paging
business, it makes the pager receiver become a
small facsimile receiver.
As an example of applying the FST to the Chinese
language in particular to the radio pager receiver
application, we found from statistic that by appropriately
selecting them, the fixed 4,000 characters can ~over over
99% of the vocabulary used in the paging industry.
Therefore, it is possible to use a unique 12 bits (one and
half byte) address fto identify a character font entry. In
other words,
Where "N" = 12 bits and
"X" = 4,000 combinations to address total 4,000
ixed characters font
residing in a 128~ x 8
bits ROM.
"Y" = 32 combinations to address a total of 32
programmable characters
from a font residing in
- part of the 8K x 8 bits
RAM.
"Z" = 63 combinations to address a total of 63
programmable phrases
residing in part of the
8K x 8 bits R~M.
"1" = 1 combination to address general
graphic inormation.
The second aspect o the invention can be used to avoid
; having to change the ID ROM to alter the pager ID. The
paging company simply send a command through wireless
transmission to the pager to achieve the same result. The
removal o the code plug will also save some space so the
pager can be made smaller. Thus, this aspect of the
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invention provides a dynamic identification (DI) technique
whereby the pager's identification code (ID) is stored in a
portion of the message RAM which is non-volatile, e~ by
being backed up by a 10 year life lithium battery, instead
of being stored in ROM. Through intelligent control by a
custom microcontroller, this identification code is no
longer pre-fixed but can be changed easily under
authorisation of the paging company to simply issue a
command to the receiver via the radio frequency channel. In
addition, more than one identification code for different
purposes of application can be stored simultaneously which
makes different categories of news broadcasting to a
particular group of subscribers easy and cost effective.
The term "radio paging device't as used in the present
description and claims is not intended to be limited to a
device dedicated solely to that purpose but is intended to
include all devices which provide th~t function in a
personally portable form. In particular, apart from its
implementation as a dedicated device, the invention may also
be put into effect by providing an acc~ssory, attachment or
insert to a personally portable electronic device having a
suitable display and effective to receive radio paging
transmissions and display them on that display.
The invention will be further described by way of non-
limitative example with reference to the accompanyingdrawings in which:-
Figure 1 is a block diagram illustrating the circuitryoE a pager in accordance with the invention; an~
Figure 2 shows how the different sub-modules are
assembled together to form a complete radio pager receiver
unit.
The pager illustrated in the attached figures comprises
a pocketable housing (not shown) preferably of the order of
size of 2 1~2" x 3" x 1/2" (63.5 x 76 x 12.7 mm) which
includes a custom one-chip MCU 1 (Microcontroller Unit -
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HD614080 from Hitachi, Japan) loaded with a speciallywritten computer program to implement each of the above
described functions, a character generator custom masked ~oM
3 (Read Only Memory, HN62321BP from Hitachi, Japan) a
graphic liquid crystal display module capable of showing 16
x 128 dots graphic or to display one frame of a certain
number of characters for a particular language (eg, for the
Chinese language, 8 characters can be shown in 16 X 16 dots
font) which comprises of 2 drivers IC 4 and 5 (LCD segments
dxiver HD611~2 and LCD common driver HD61103 from Hitachi,
Japan) and a high contrast LCD display 6 custom made bv
Seiko with which the whole LCD module is powered by a
specially designed LCD power supply circuit 7, a lithium-
battery-backed message storage readtwrite RAM 2 (HN6264FLP-3
from Hitachi, Japan) of capacity 8K x 8 bits for storing
message data, one or more pager identification codes and
some programmable Oriental language characters; in
particular, the Chinese character fonts and phrases. A key
panel 10 comprises one 3 position sliding mode switch to
activate the pager and 5 push-buttons ~or users operations.
A radio ~requency (RF) receiver module 8 comprises RF tune
circuit, amplifier, filters and wave shaping circuits as a
hybrid unit for capturing data signal from the air, a beeper
and a light-emitting diode (LED) to generate the audio and
visual alert signal upon message received, one piece o~ 1.5
volt AA-size battery 11 to power the RF receiver module 8, a
DC-DC converter 9 to step up the voltage from battery 11 to
power the remaining system and finally s small light bulb 1~
or some other lighting device to provide background lighting
to LCD module.
The pager is constructed (refer to Figure 2) and
programmed so that it can receive specially coded message
and display characters of the Oriental languages, in
particular, the Chinese language under user's control. The
following paragraph descri~es the operation principle of the
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pager.
The pa~i.ng company transforms the message in the
Oriental language, in particular, the Chinese language or
graphic information context using the paging computer system
into a binary bit stream based on the floating storage
technique coding algorithm, and then associate the message
with either a specific pager receiver subscriber or the
group broadcasting subscribers plus some redundant bits for
self error correction and finally encode all data bits as a
complete message packet according to the Universal POCSAG
standard (CCIR radio paging code No 1) and broadcast to the
air through a parti~cular radio frequency channel.
Assuming the pager has been switched active, the MCU 1
wakes up the RF receiver module 8 from time to time to
detect if there is any message which requires its attention
by comparing the identification code associated with the
message with its own identification stored in the RAM 2
according to the dynamic identification concept. I the
result is positive, MCU 1 stores the message into the RLM 2
for later repeated examination, and at the same time,
searches the character generator ROM 3 and other
programmahle characters font or phrases table in RAM 2 to
transform the message into the Oriental language or Chinese
character or other graphic information then shows the
message on the LCD module. In addition, a alert tone is
generated by the beeper unit and the LED is flashed inside
the RF module 8 which is controlled again by the MCU 1. The
user can switch off the tone by hitting any button on the
key panel 10; otherwise, the tone will be turned off
automatically after about 8 seconds by the MCU 1.
Battery 11, DC/DC converter 9 and ~CD power circuit 7
; to serve to distribute the power to individual wo~king
modules of the pager. If the environment is dark and the
LCD cannot be seen clearly, the user can press and hold the
"LIGHT" button on the key panel 11 to turn on the light bulb
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11
or to the lighting devices 12 to have display illumination.
The beep tones can be substituted by a vibration alert
unit if the user does not wish the tone to disturb other
people.
The pager may provide both manual and auto time shut-
off features to conserve power consumption. Battery low
alert/indication is also provided.
The program of the MCU 1 can interpret information
which has been encoded into a bit stream according to the
Oriental language; in particular the Chinese character,
coding system specially designed for the present invention
based on the said forth floating storage technique and
transmitted in standard POCSAG format in 512 baud speed or a
higher band speed switchable by the paging company. It can
also support standard POCSAG alphanumeric display.
During data reception, the pager may provide 2 bits
self error correction and 3 ~its error detection capability
for identification code matching while 1 bit self error
correction and 2 bits error detection capability for message
reco~ery to ensure maximum receiving reliability.
With RAM 2, the said pager can store up to 32 separate
messages, the maximum length of each message is depending on
how the floating storage technique is being used, with no
practical restriction. Standard alphanumeric messages
transmitted in POCSAG format can also be recognised. The
screen formats of the LCD module are different between the
Oriental language; in particular the Chinese characters, and
alphanumeric-characters display mode. In the former, each
frame can display a number of Oriental language characters;
in particular, 8 Chinese characters in 16 x 16 dot fonts; in
the latter, each frame can display 2 lines x 21 characters
in 5 x 7 dot font. In addition, the pager can support both
small and capital letter alphabets. The next paragraph will
describe the detailed user operation of the pager.
The pager is suitabLe programmed so as to operate in
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one of the following 4 states:-
a) Active state.
The MCU 1 receives and executes commands from the uservia the key panel 10, allocating some spare time
; 5 periodically to check if any message is coming from the RF
receiver. Power is supplied to all components in this
state.
b) Sleep state
System will go to sleep state from Active State is NO
key on the keyboard has been pressed for approximately 30
seconds or the user has stepped through all the stored
messages. In thisJstate, the hCD module will be switched
off. ~
c) Disable stage
The pager will enter this state if a DISABLE command
has been received. This state is similar to the Sleep State
except that further users' commands ~ill not be effective
until an ~NAB~E command is received tnrough broadcast.
d) Off State
User Switches the pager to this state by sliding the
. mode switch to the OFF position. All components except the
~, external RAM chip 2 will be cut off. The pager cannot
receive any further message until turned back on.
In the following, NORMAL operation refers to operating
the pager under Active or Sleep state.
The key panel 10 will be provided with the following
keys, switches and buttons, the MCU 1 suitabLy programmed to
produce operation as described.
- 1 Mode switch: A 3 position slide switch with its
position to define the different users
operation modes:
ON: The pager is under Active or Sleep
stage while an alert tane will be
heard and LED will be flashed
- 35 whenever a call has been received.
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M: Same as ON made except the alert
tone will be disabled.
OFF: Pager is OFF. All memorised
messages will be erased.
2 Next button:- Enable user to examine individual
message in frame by frame basis if the
- message is too long to be fitted within
~ one frame.
3 READ button: Enable user to read next message in
FORWARD direction. ~atest message will
be placed at the top position of the RAM
buffer.
4 BACK button: Enable user to read next message in
BACKWARD direction.
15 5 DELETE button: Enable user to delete the current
examined message from the RAM buffer.
The delete all mçssages, user can press
both the READ and BACK button.
6 Light button: Display illumination will be effective
if this hutton has been pressed and held
down.
The provision of the above functions, both insofar as
they are implemented by programming of the microprocessor
and by the illustrated circuitry is a matter of routine for
the skilled man.
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