GB2274528A - Paging receiver - Google Patents

Abstract

A paging receiver for use in a numeric data paging system, comprises a casing having a LCD display (12) thereon and microprocessor-based electronic circuitry (20) provided within the casing, said electronic circuitry (20) comprising a central processing unit (21), receiver (22) and demodulator (26) for receiving and demodulating an incoming numeric data paging signal, a signal decoder (31) connected from the demodulator (26) to the central processing unit (21) for decoding the demodulated paging signal, and ROM-based conversion means (33) connected to the central processing unit (21) for converting the or an appropriate segment of the decoded paging signal into a graphic pattern for display on the LCD display (12) under the control of the central processing unit (21). <IMAGE>

Description

PAGING RECEIVER The present invention relates to a paging receiver.

There are two major types of existing paging systems, namely numeric data and character paging systems. In the numeric data paging system, paging signals contain numeric information data which are in serial binary/bit form and modulated upon a radio frequency carrier for transmission.

In the character paging system, the paging signals are formatted and transmitted in like manner, but the characters, such as Chinese characters, Roman letters and words and special symbols, are encoded according to a particular encoding scheme before further processing for transmission. Such an encoding scheme renders the data input operation at paging centres relatively more complicate and slow, thereby reducing the data input and data processing speeds compared with that in a numeric data paging system. Also, the encoded character paging signals are inevitably longer than the equivalent numeric data paging signals, and this requires longer transmission or air time.

It is usually necessary for the numeric data paging users to look up a printed code table in order to understand fully the numeric messages displayed on the 7-segment display of the numeric data paging receivers. Most paging calls (over 80% to 90%) consist of a surname or name of the paging parties, their contact telephone number or a standard message, for which numeric data paging receivers are sufficiently convenient to handle. Also, by reason of the relatively lower machine costs and service fees and higher responding speed, the numeric paging systems and their user population are considerably larger than the character paging systems.

The invention seeks to provide a paging receiver which is operable in a standard numeric data paging system and yet capable of displaying graphic patterns including Chinese characters, Roman letters and words and dedicated symbols for direct read out.

According to the invention, there is provided a paging receiver for use in a numeric data paging system, which paging receiver comprises a casing having a LCD display thereon and a microprocessor-based electronic circuity provided within the casing, said electronic circuitry comprising a central processing unit, receiver and demodulator for receiving and demodulating an incoming numeric data paging signal, a signal decoder connected from the demodulator to the central processing unit for decoding the demodulated paging signal, and ROM-based conversion means connected to the central processing unit for converting the or an appropriate segment of the decoded paging signal into a graphic pattern for display on the LCD display under the control of the central processing unit.

Preferably, the ROM-based conversion means contains a plurality of graphic patterns which are stored according to a particular addressing scheme, and wherein the ROM-based conversion means further includes address mapping means for providing the central processing unit with an appropriate address corresponding to the or said segment of the decoded paging signal in order for the central processing unit to retrieve the corresponding graphic pattern according to that address.

It is preferred that the ROM-based conversion means is arranged to determine the appropriate segment of the decoded paging signal for conversion into a corresponding graphic pattern for display on the LCD display.

Preferably, the conversion means and the address mapping means are provided in a single integrated circuit chip.

The graphic patterns may represent, inter alia, Chinese characters, Roman letters and/or dedicated symbols.

It is advantageous for the central processing unit to include display control means for controlling the LCD display to display a graphic pattern requiring more than one screenful of the LCD display.

More specifically, the display control means is arranged to control the LCD display to display two pages of a graphic pattern in an alternating manner.

It is preferred that the central processing unit and the signal decoder are provided as separate integrated circuit chips.

In a preferred embodiment, the LCD display comprises a dot matrix display for displaying a graphic pattern and a numeric display for displaying numeric information contained in the same paging signal.

Preferably, the dot matrix display is arranged to have 16 by 16 dots or 24 by 24 dots.

It is preferred that the casing is card-sized.

The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a front view of a paging receiver in accordance with the invention; Figure 2 is an enlarged view showing a LCD display of the paging receiver of Figure 1; Figure 3 is a schematic block diagram showing an electronic circuitry of the paging receiver of Figure 1; Figure 4 is a flow chart illustrating a message receiving operation of the electronic circuitry of Figure 3; Figure 5 is a flow chart illustrating a message displaying operation of the electronic circuitry of Figure 3; Figure 6 is a simplified flow chart illustrating a graphic pattern retrieving and displaying operation of the electronic circuitry of Figure 3; and Figure 7 is a flow chart illustrating a stored message reviewing operation the electronic circuitry of Figure 3.

Referring firstly to Figures 1 and 2 of the drawings, there is shown a paging receiver 10 embodying the invention, which paging receiver 10 comprises a card-sized casing 11 on which a LCD display 12 and three feather-touch keys 13 marked READ, MODE and SELECT, respectively, are provided.

The paging receiver 10 further includes a speaker and an LED indicator (not shown) on the left side of the casing 11.

The LCD display 12 has a 16x16 (or alternatively 24x24) dot matric display 14 on the left side and a 9-digit 7-segment numeric display 15 extending from the dot matrix display 14 to the right side. The LCD display 12 further includes a sex indicator 16 for the paging party, a single digit 7segment numeric display 17 for indicating stored message sequence number, and fourteen dedicated symbols for various other indications, such as message protection, automatic timer, call/message types, signal strength, weak battery, alert tone on/off and message continuation.

The paging receiver 10 is designed to be used in an existing numeric paging system, of which the paging signal contains purely numeric information data encoded in serial bit form and modulated upon a radio frequency carrier for transmission. The carrier frequency is typically 280MHz.

A numeric paging signal normally includes two principal segments of data, namely a code and a number. Typically, the code segment represents a surname or name of the paging party and the number segment represents the paging party's contact telephone number.

The paging receiver 10 has a microprocessor-based electronic circuitry 20 as shown in Figure 3, provided within the casing 11. The electronic circuitry 20 is controlled by a central processing unit or CPU 21 and further includes a paging signal receiving circuit 22 formed by a built-in antenna 23, a radio frequency amplifier 24 and a saw filter 25 which is a high sensitivity narrow band-pass filter. Following the receiving circuit 22, there is provided a demodulating circuit 26 for demodulating the received paging signal back into serial bit form. The demodulating circuit 26 has a local oscillator 27 tuned at a frequency of 455kHz and Co- operates with a mixer 28 for stepping down the carrier frequency of the received paging signal to 455kHz for easy handling.The resulting paging signal is then amplified by an intermediate frequency amplifier 29 and subsequently demodulated by a demodulator 30. The paging signal receiving and demodulating circuits 22 and 26 are generally known for existing numeric paging receivers.

The electronic circuitry 20 further includes a generally standard POCSAG decoder 31 connected between the demodulating circuit 31 and the CPU 21. The POCSAG decoder 31 is an integrated circuit containing a standard firmware for decoding digital paging signals which are encoded before transmission according to a standard encoding scheme generally known as "POCSAG" in the art for paging and signal transmission. An identity ROM 32 containing an identity code for this particular paging receiver 10 is connected to the POCSAG decoder 31, for reference by the CPU 21. With a matching incoming identity code, the CPU 21 will respond to process the received paging signal.

The electronic circuitry 20 further includes a custom-made ROM-based conversion unit 33 connected to the CPU 21. The conversion unit 33 contains a set of graphic patterns including inter alia Chinese characters (fonts), Roman letters (fonts) and dedicated symbols, and includes an internal address mapping firmware. The LCD display 12 and the keypad 13 are also connected to the CPU 21. The set of graphic patterns is stored in part of the memory of the conversion unit 33 according to a specific addressing scheme and is arranged to be displayed selectively on the LCD dot matrix display 14 under the control of the CPU 21.

The address mapping firmware serves to supply an appropriate address to the CPU 21 according to a specific segment of the incoming paging signal decoded by the POCSAG decoder 31. The CPU 21 bases on this supplied address to fetch an appropriate graphic pattern from the conversion unit 33 for display on the dot matrix display 14, as will be more fully described with reference to Figure 6.

The paging signal/message receiving operation of the electronic circuitry 20 will now be described with reference to Figure 4. Upon receiving a paging call (Box 40), the CPU 21 is interrupted (Box 41) to receive and store the serial bit data from the POCSAG decoder 31 (Boxes 42 and 43). The CPU 21 decodes and analyses the serial bit data (Box 44) and subsequently converts the serial bit data into hexadecimal code (Box 45).

In this particular paging system and embodiment, the numeric paging messages are classified into five major categories, namely: Type I - "Tone Only" which contains no specific numeric data but requires the paged user to call the paging centre for verbal message (Box 46); Type II "Chinese Surname or Given Name" which contains the surname or name of the paging party, with or without contact telephone number (Box 47); Type III - "Christian Name" which contains the English name of the paging party, with or without contact telephone number (Box 48); Type IV "Dedicated Symbol" which is numeric-coded, with or without contact telephone number of the paging party (Box 49); and Type V - "Number Only" which contains only the contact telephone number of or any designated number for the paging party (Box 50).The dedicated symbols are in symbol as well as script forms including messages like "home calling", office calling", "same place to meet" and "wait until you arrive", etc.

The CPU 21 will classify all these message types by means of logic decisions (Boxes 46 to 50) and then assign appropriate index codes and numbers to them (Boxes 51 to 55). In case of Types II and III messages, the CPU 21 will also detect and assign an additional sex code (Boxes 56 and 57). The content of the received message is then checked to see if it is a repeated call (Box 58). If the received message is a repeated call, a repeat flag will be assigned (Box 59). If the same message is also protected (Box 60), a protect flag will further be assigned (Box 61). Upon completion of these checking and/or flagging steps, the received message will be stored in the coded form with any necessary flags (Box 62) and further with the time of receipt (Box 63).

The paging signal/message displaying operation of the electronic circuitry 20 will now be described with reference to Figure 5. At the beginning of the operation (Box 70), the stored message in the coded form is reclassified according to the message type (Boxes 71 to 75 which are equivalent to Boxes 46 to 50 of Figure 4). Being any one of Types I to IV, the message will be processed for display on the LCD display 12. In this process, the CPU 21 will read a corresponding graphic pattern from the conversion unit 33 (Box 76) and display the same on the LCD dot matrix display 14 (Box 77) and further display the remaining numeric data on the LCD numeric display 15 (Box 78). Any additional information such as flags, call type and calling party's sex will also be displayed by means of the subsidiary indicators 16 to 18 (Box 79).

The graphic pattern read may require more than one screenful of the LCD dot matrix display 14 to display. In this embodiment, the graphic patterns are designed to take either one or two screens of the LCD dot matrix display 14.

A double-screen graphic pattern is identified by a toggle flag which will be detected by the CPU 21 (Box 80). In the presence of a toggle flag, the CPU 21 will read the second page of the graphic pattern from the conversion unit 33 (Box 81) and then toggle the two pages of the graphic pattern on the LCD dot matrix display 14 for every second (Box 82). This toggling display manner will enable the user to read the whole graphic pattern such as a double surname, a longer dedicated message "wait until" and "you arrive", or a telephone symbol and a house symbol requiring the user to telephone home.

In a different display manner, the two or more pages of an extended graphic pattern may be scrolled sequentially from right to left across the LCD dot matrix display 14.

With the subject paging message being of Type V (Box 75), the numeric data will be directly displayed on the LCD numeric display 15 (Box 83) together with any additional information such as flags and call type (Box 84).

Once the paging message is displayed, an audible, visible and/or vibration alert signal will be given (Box 85). The alert signal will last for about 8 seconds (Box 86) before being automatically turned off, or will be turned off earlier if a key 13 is pressed (Box 87).

The manner in which the CPU 21 reads and displays a graphic pattern is best illustrated in Figure 6. Upon receiving a graphic-related paging message (Box 90), the CPU 21 will enable the conversion unit 33 to run the address mapping firmware to analyze and decode the paging message (Box 91), to analyze and search for the required graphic pattern (Box 92), to assign an internal sequence and code number (Box 93), and to look up an index address or addresses (for example two addresses for a double-screen graphic pattern) for the required graphic pattern according to the assigned sequence and code number (Box 94).

The CPU 21 reads and stores the index address (Box 95) and then fetches the appropriate graphic pattern from the set of graphic patterns (including characters, letters, data and symbols) stored in the conversion unit 33, according to the index address (Box 96). The CPU 21 will display the retrieved graphic pattern on the LCD dot matrix display 14 (Box 97) and will subsequently check whether there is a toggle flag for toggling the two pages of the graphic pattern (Box 98) if necessary.

Referring now to Figure 7, the stored paging signal/message reviewing operation is substantially similar to the initial displaying operation as illustrated in Figure 5, with the equivalent Boxes designated by corresponding numerals suffixed by "A". The reviewing operation normally displays the stored messages in sequence (Box 99A) and along side with the corresponding message sequence numbers (Box 100A).

In this embodiment, the "POCSAG" decoder 31 and the CPU 21 are provided as separate integrated circuit chips. It is envisaged that the two circuits may be integrated into a single chip to reduce chip count and production cost.

Also, the conversion unit 33 may be integrated into the central processing unit. It is further envisaged that the LCD display may include a pair of adjacent dot matrix displays or be entirely of dot matrix type to provide maximum flexibility for message and graphic displaying.

The paging receiver according to the invention is operable on existing numeric data paging systems, with the capability of displaying direct read-out graphic patterns including Chinese characters, Roman letter and dedicated symbols. No modifications or adaptation of the existing data paging systems are necessary.

The invention has been given by way of example only, and various other modifications of and/or alterations to the described embodiment may be made by persons skilled in the art without departing from the scope of the invention as specified in the appended claims.

Claims (12)

1. A paging receiver for use in a numeric data paging system, which paging receiver comprises a casing having a LCD display thereon and a microprocessor-based electronic circuity provided within the casing, said electronic circuitry comprising a central processing unit, receiver and demodulator for receiving and demodulating an incoming numeric data paging signal, a signal decoder connected from the demodulator to the central processing unit for decoding the demodulated paging signal, and ROM-based conversion means connected to the central processing unit for converting the or an appropriate segment of the decoded paging signal into a graphic pattern for display on the LCD display under the control of the central processing unit.

2. A paging receiver as claimed in claim 1, wherein the ROM-based conversion means contains a plurality of graphic patterns which are stored according to a particular addressing scheme, and wherein the ROM-based conversion means further includes address mapping means for providing the central processing unit with an appropriate address corresponding to the or said segment of the decoded paging signal in order for the central processing unit to retrieve the corresponding graphic pattern according to that address.

3. A paging receiver as claimed in claim 1 or claim 2, wherein the ROM-based conversion means is arranged to determine the appropriate segment of the decoded paging signal for conversion into a corresponding graphic pattern for display on the LCD display.

4. A paging receiver as claimed in claim 2 or claim 3, wherein the conversion means and the address mapping means are provided in a single integrated circuit chip.

5. A paging receiver as claimed in any one of claims 1 to 4, wherein the graphic patterns represent, inter alia, Chinese characters, Roman letters and/or dedicated symbols.

6. A paging receiver as claimed in any one of the preceding claims, wherein the central processing unit includes display control means for controlling the LCD display to display a graphic pattern requiring more than one screenful of the LCD display.

7. A paging receiver as claimed in claim 6, wherein the display control means is arranged to control the LCD display to display two pages of a graphic pattern in an alternating manner.

8. A paging receiver as claimed in any one of the preceding claims, wherein the central processing unit and the signal decoder are provided as separate integrated circuit chips.

9. A paging receiver as claimed in any one of the preceding claims, wherein the LCD display comprises a dot matrix display for displaying a graphic pattern and a numeric display for displaying numeric information contained in the same paging signal.

10. A paging receiver as claimed in claim 9, wherein the dot matrix display is arranged to have 16 by 16 dots or 24 by 24 dots.

11. A paging receiver as claimed in any one of the preceding claims, wherein the casing is card-sized.

12. A paging receiver substantially as hereinbefore described with reference to Figures 1 to 7 of the accompanying drawings.