CA1313225C

CA1313225C - Chinese character display pager

Info

Publication number: CA1313225C
Application number: CA000571260A
Authority: CA
Inventors: Susanna Katherine Kan
Original assignee: Chinese Computers Ltd
Current assignee: Chinese Computers Ltd
Priority date: 1987-07-07
Filing date: 1988-07-06
Publication date: 1993-01-26
Anticipated expiration: 2010-01-26
Also published as: CN1030491A; JPH0199086A; SG49292G; SG49092G; HK57492A; HK57392A; GB8715964D0; JPH0754427B2; GB2207265B; GB2206718B; GB2206718A; GB8803418D0; GB2207265A; KR890003148A; CN1028810C; KR960001579B1

Abstract

A display device for displaying alphanumeric and/or pictographic characters such as of an Oriental language including Chinese, Korean and Thai and/or graphic information. The device includes radio receiving circuitry for receiving a radio message in which is encoded characters and/or graphic images to be displayed and at least one display for displaying the received message as characters and/or as a graphic image. Processing circuitry is adopted to receive the radio message as N-bit message data words from the receiving circuitry, and to convert the data words into displayed characters and/or graphic images in a manner such as to extend the total number of displayable characters and/or graphic images beyond 2N (2 raised to the power N) by using at least one of the 2N possible data words to alter the conversion used to generate the characters and/or usage. The device includes circuitry for storing the value of at least one parameter used by circuitry of the device for defining a characteristic of its operation and circuitry responsive to at least one command encoded in a received message to set out at least one such parameter to a required value. Among the parameters which may be set in this way is the identification code of the device.

Description

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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 . ' ' 13:~32~

2 72~3~-1 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 ~` 3 1313~ 72832-1 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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3a 72832-1 (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 <
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 -~3~322~

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 - 13~2~

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 - ` ~31322~

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 ~3 1 3~2~

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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Claims

1. 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 graphical images, which may include character font images, at addressable locations;
(d) processor means, connected to said receiver 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 of 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 means by the 2N possible address codes exceeds 2N;
and (e) display means connected to said processing means for displaying the graphical images retrieved from said fixed memory means and said volatile memory means by said addressing means.

2. A device according to Claim 1, wherein said fixed graphical images stored in said fixed memory means comprise a predetermined character table.

3. A device according to Claim 2, wherein said predetermined character table has about 4000 graphical images, which may include character font images, stored therein, and wherein N equals 12.

4. A device according to Claim 2, wherein said changeable graphical images stored in said volatile memory means comprise a variable character table.

5. A device according to Claim 3, wherein said variable character table has addresses for at least 32 graphical images, which may include character font images, and wherein N equals 12.

6. A device according to Claim 4, wherein said changeable graphical images stored in said volatile memory means comprise a pointer table storing pointers for cascading a sequence of character entries from within said predetermined character table and said variable character table to produce phrases of graphical images, which may include character font images.

7. A device according to Claim 6, wherein said pointer table has addresses for at least 63 pointers and wherein N equals 12.

8. A device according to Claim 1, wherein said fixed memory means includes a read-only memory in which predetermined graphical images are stored at a first predetermined number of addressable locations, said first predetermined number being less than 2N, and wherein said addressing means is operative for addressing the predetermined graphical images in said read-only memory utilizing said first predetermined number of addressable locations.

9. A device according to Claim 8, wherein said volatile memory means includes a random access memory in which programmable graphical images are stored at a second predetermined number of addressable locations, said second predetermined number being less than 2N, each programmable graphical image consisting of any individual data element, and wherein said addressing means is operative for addressing the programmable graphical images in said random access memory utilizing said second predetermined number of addressable locations.

10. A device according to Claim 9, wherein the programmable graphical images constitute programmable phrases stored in said random access memory at a third predetermined number of addressable locations, each phrase consisting of multiple data elements, said third predetermined number being less than 2N, and wherein said addressing means is operative for addressing the programmable phrases in the random access memory utilizing said third predetermined number of addressable locations.

11. A device according to Claim 10, wherein the programmable graphical images constitute general graphic information stored in the random access memory at a fourth predetermined number of addressable locations, said fourth predetermined number being less than 2N, and wherein said addressing means is operative for addressing the general graphic information in said random access memory utilizing said fourth predetermined number of addressable locations.

12. A device according to Claim 11, wherein the sum of said first, second, third and fourth predetermined numbers equals 2N.

13. A device according to Claim 12, wherein N equals 12; and wherein said first, second, third and fourth predetermined numbers are 4000, 32, 63 and 1, respectively.

14. A device according the Claim 1, said device being a radio pager having a volatile memory in which a unique identification code is stored, wherein the radio message received by said receiver means may contain encoded identifying indicia, and wherein said processor means includes means for comparing the encoded identifying indicia to the stored identification code to determine whether a received radio message is intended for radio pager.

15. A device according to Claim 1, further comprising control means connected to said display means for controlling the manner in which the graphical images are displayed.

16. A device according to Claim 15, wherein said control means includes a first actuator for controlling, when actuated, the forward sequence in which the graphical images are to be viewed.

17. A device according to Claim 16, wherein said control means includes a second actuator for controlling, when actuated, the amount of graphical images to be displayed upon each viewing.

18. A device according to Claim 17, wherein said control means includes a third actuator for controlling, when actuated, the backward sequence in which the graphical images are to be viewed.

19. A device according to Claim 18, wherein said control.
means includes a fourth actuator for controlling, when actuated, the deletion of graphical images.

20. A device according to Claim 1, wherein the graphical images stored in said fixed memory means and in said volatile memory means correspond to language characters selected from the group consisting of the Oriental languages including the Chinese, Koreans, and Thai languages.

21. A device for displaying graphical images, comprising:
(a) receiver means for receiving radio messages containing at least one of (1) graphical information, which may include character font information, to be displayed, and (2) command data;
(b) display means for displaying graphical images, which may include character font images, corresponding to graphical information received by said receiver means;
(c) volatile memory means for changeably storing an identifying code identifying said device; and (d) processor means connected to said receiver means, for precessing radio messages 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 data received by said receiver means for altering the identifying code identifying said device and stored in said volatile memory means.

22. A device according to Claim 4, said device being a radio pager, and (1) wherein said radio message received by said receiver means contains encoded identifying indicia, and (2) wherein said processor means includes means for comparing the encoded identifying indicia with the identifying data stored in said volatile memory means to determine whether a received radio message is intended for said radio pager.