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`Europfiisches Patentamt
`European Patent Office
`Office européen des brevets
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`@ Publication number: 0 342
`B1
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`@
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`EUROPEAN PATENT SPECIFICATION
`
`Date of publication of patent specification :
`26.04.95 Bulletin 9511'.’
`
`@ Int. CL“: H04-Q THO, GOBB 5l22
`
`@ Application number: 891088535
`
`@ Date of filing: 17.05.39
`
`@ Radio paging communication system.
`
`Priority: 17.05.88 JP 12DD3DI'88
`31.08.83 JP 215267I'88
`
`Date of publication of application :
`23.11.89 Bulletin BSM7
`
`Publication of the grant of the patent:
`26.04.95 Bulletin 9511?
`
`Designated Contracting States:
`DE FR GB
`
`References cited :
`GB-A- 2 124 419
`GB-A- 2 197 103
`US-A- 4 382 256
`PATENT ABSTRACTS OF JAPAN vol. 8, no.
`111 [E-24B){15-48) 24 May 34, & JP-A-59 25429
`(NEG) 09 February B4,
`NTT REVIEW. vol. 1. no. 1, May 89, TOKYO JP
`pages 45 - 53; M. WADA: "NTT PagingSys-
`tern"
`
`@ Proprietor: CASIO COMPUTER COMPANY
`LIMITED
`6-1, 2-chome, Nishi-Shinjuku
`Shinjuku-ku Tokyo ‘£80 {JP}
`
`® Inventor: Shimura. Kazuhiro clo Patent Dept.
`Development Div
`Hamura R
`D Center
`CASIO COMP CO.,LTD.
`3-2-1,Sakae-
`Harnure-machi Nishitama-gun Tokyo 190-11
`JP
`Inventor: lwahara, Kenji cfo Patent Dept.
`Development Div
`Hamura R
`D Center
`CASIO COMP CO.,LTD.
`3-2-1,3akae-
`Hamura-machi Nishitama-gun Tokyo 190-11
`(JP)
`
`@ Representative : Patentanwfilte Griinecker,
`Kinkeldey, Stockmair & Partner
`Maximilianstrasee 58
`D-80533 Mfinchen (DE)
`
`EP0342638B1
`
`Note: Within nine months from the publication of the mention of the grant of the European patent, any
`person may give notice to the European Patent Office of opposition to the European patent granted.
`Notice of opposition shall be filed in a written reasoned statement.
`It shall not be deemed to have been
`filed until the opposition fee has been paid (Art. 99(1) European patent convention).
`
`Jouve, 13, rue Saint-Denis, 75001 PARIS
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`GOOGLE 1012
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`EP III 342 638 B1
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`Description
`
`The present invention relates to a paging receiver
`used in a radio paging communication system.
`A numeric display paging receiver and an alpha-
`numeric display paging receiver are availabte as re-
`ceivers capabie of receiving message date from a
`caller and displaying the message data in convention-
`al radio paging communication systems. A most con-
`venient data input means for transmitting message
`data to a paging receiver is a key telephone set.
`Although the key telephone set is used as an in-
`put means for inputting message date to a numeric
`display paging receiver in a conventional radio paging
`communication system. the key telephone set is not
`used as an input device for inputting message data to
`an aiphanumeric display paging receiver due to the
`following reason. Message data is not input to the al-
`pha-numeric display paging receiver without using an
`exclusive data inputterminal such as a personal com-
`puter. The alphanumeric display paging receiver has
`an advantage in that perfectly free letter infonriation
`can be received, while the numeric dispiay paging re-
`ceiver can receive only numeric information as mes-
`sage data. However, the alpha~numeric display pag-
`ing receiver is not yet popular in spite of the above ad-
`vantage.
`At the time of transmission of message data to
`the alpha-numeric display paging receiver in the con-
`ventional radio paging communication system, even
`if message contents represent numeric information
`such as a destination telephone number. the mes-
`sage data is coded as an alpha-numeric code.
`US-A-4 382 256 (D1) discloses a prior art paging
`receiver which demodulates a carrier wave with a
`
`paging signal code and a plurality of information key
`codes. The demodulated information key codes are
`decoded by the paging receiver when its own paging
`signal code is detected. The paging receiver contains
`a plurality of words corresponding to said infonnation
`key codes. These stored words are read out when
`they correspond to the decoded information. The read
`out codes are then displayed.
`A disadvantage of the above mentioned receivers
`is that transmission efficiency of the message data is
`undesirably degraded.
`It is an object of the present invention to provide
`a radio paging communication system capable of
`transmitting message data from a normal key tele-
`phone set to an alpha-numeric display paging receiv-
`er.
`
`It is another object of the present invention to pro-
`vide a method of effectively transmitting message
`data consisting of or including numeric information to
`the alpha-numeric display paging receiver.
`it is another object of the present invention to pro-
`vide an improved alpha-numeric display paging re-
`ceiver.
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`It is still another object of the present invention to
`provide a paging receiver with an improved function-
`ality and convenience of operation, in particular by
`making it possible to use a wide variety of coded mes-
`sages.
`These objects can be achieved by the features of
`claim 1.
`
`By providing means for detachably connecting
`the standard expression memory it is possible to have
`standard expression memories for different applica-
`tions. Thus, a user may use standard expression
`memories for business-use. private-use. etc. Also the
`paging receivers may be customized for differing pro-
`fessionai needs. Paging receivers in hospitals, factor-
`ies or offices may need different sets of standard ex-
`pressions. These different needs of the above men-
`tioned working environments may befulfilled by mak-
`ing standard expression memories detachably con-
`nectable to the paging receivers.
`Further, by displaying the standard expression
`designating code when the specific standard expres-
`sion memory means is not connected to the paging
`receiver, the paging receiver remains functional even
`without a standard expression memory connected. In
`every day life, the detachable standard expression
`memory may get lost. In that case. the paging receiv-
`er would be rendered useless unless. as described
`
`above. the standard expression designating code is
`displayed. The user can then recognize not only
`whether the standard expression memory is connect-
`ed or not, but also which standard expression is stor-
`ed in the standard expression memory, provided the
`user has written down the standard expression or has
`memorized the standard expression corresponding to
`the standard expression designating code.
`This invention can be more fuily understood from
`the following detailed description when taken in con-
`junction with the accompanying drawings, in which:
`Fig. 1 is a block diagram showing a system con-
`figuration ofa base station in a radio paging com-
`munication system:
`Figs. 2Ato 2D are formats ofa radio paging signal
`code;
`Fig. 3 is a table showing a JIS (Japanese indus-
`trial Standards) B-bit code set;
`Fig. 4 is a block diagram showing a circuit ar-
`rangementof a paging receiver used in the radio
`paging communication system according to a
`first embodiment of the present invention;
`Fig. 5 shows a data format of data stored in a
`RAM shown in Fig. 4;
`Fig. 6 is a table showing abbreviation Nos. and
`contents of the corresponding standard expres-
`sions;
`Fig. 7 is a table showing codes corresponding to
`the key operations of abbreviation Nos. and char-
`acters;
`Fig. 8 is a flow chart showing receiving process-
`
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`EP III 342 638 B1
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`ing;
`Fig. 9 is a flow chart showing readout processing;
`Fig. 10 is a flow chart showing readout data dis-
`play processing (Fig. 9) in detail;
`Fig. 11 is a view showing examples of transmis-
`sion of standard expression abbreviation Nos.;
`Fig. 12 is a block diagram showing a circuit ar-
`rangement of a paging receiver according to a
`second embodiment of the present invention;
`Fig. 13 is a perspective view of the paging receiv-
`er and its detachable standard expression mem-
`cry; and
`Fig. 14 is a flow chart showing readout process-
`ing of the second embodiment.
`Fig. 1 is a block diagram showing a system con-
`figuration of a base station in a radio paging commu-
`nication system. Referring to Fig. 1, reference numer-
`al 1 denotes a key telephone set; and 2. a personal
`computer having a communication function. The key
`telephone set 1 and the personal computer 2 are used
`as inputterminals forcausing a callerto input a calling
`number of a paging receiver and a message thereto.
`The key telephone set 1 and the personal computer
`2 are connected to a control center 4 of the base sta-
`
`tion through public telephone line 3.
`The control center 4 includes an IIO circuit 5 con-
`
`nected to the public telephone line 3. The ll0 circuit
`includes a modem and an answering circuit. A calling
`number input by the caller at the key telephone set 1
`or the personai computer 2 is input to a collator 6
`through the public telephone line 3 and the U0 circuit
`5. The collatorfi collates the input calling number with
`calling numbers of a plurality of su bscriber's receivers
`which are stored in a subscriber's receiver memory 7.
`when the input calling number does not coincide with
`any one of the calling numbers stored in the memory
`7. the collator 6 sends a command to the answering
`circuit in the HO circuit 5 to cause the answering circuit
`to send to the caller a message "The designated call-
`ing number is not registered at present". However.
`when the input calling number coincides with one of
`the calling numbers stored in the memory 7. the col-
`later 6 sends the input calling numberwhich coincides
`with one of the stored calling numbers to a signal
`processor 8. At the same time, the collator 6 outputs
`one of the different commands based on different
`
`types of paging receivers in accordance with the des-
`tination paging receiver assigned with this calling
`number. The selected command is output to the U0
`circuit 5 and the signal processor 8. when the type of
`paging receiver assigned with the input calling nurn-
`ber coinciding with the stored calling number is a
`tone-only type having no display device. the collator
`6 sends a command to cause the I70 circuit 5 to send
`
`a message "Calling is started. Please hang up the
`phone and wait" to the caller. The collator 8 sends a
`command to cause the signal processor 8 to send a
`paging signal. When the type of pager receiver is a
`
`numeric display type having a seven segments type
`display device, the collator 6 sends a command to the
`I10 circuit 5 to cause it to send a message "Please in-
`put a message.” to the caller. In this case. the collator
`6 sends a command to the sig nal processor 8 to cause
`it to treat the message data input from the caller as a
`numeric code, i.e., 4-bit coded data. When the type of
`paging receiver is an alpha-numeric display type hav-
`ing a matrix type display device, the collator 6 sends
`a command to the HO circuit 5 to cause it to send a
`
`message "Please input a message." to the caller. In
`this case. the collator 6 sends a command to the sig-
`nal processor 8 to cause it to treat the message data
`input from the caller as an alpha-numeric code, e.g..
`JIS (Japanese lndustriat Standards) 8-bit coded data.
`The message data from the caller is input to the
`signal processor 8 and a detector 9 through the IIO
`circuit 5. The detector 9 detects a shift code which
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`represents that the subsequent data in the message
`data is numeric code data when the shift code is in-
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`cluded in the message data. The shift code can be
`constructed by device control codes DC1 to DC3 in
`alpha«numeric codes {e.g.. an ISO 7-bit code, an AS-
`Cll code which complies with the ISO 7-bit code. a JIS
`7«bit code. or a JIS 3-bit code), or nondefined codes
`in these alphanumeric codes. When the shift code is
`used as a code which represents that the subsequent
`numeric data represents a standard abbreviation No..
`it must be a combination ofcontinuous numeric codes
`
`which will not be found in a normal data input, as will
`be described later. When the detector 9 detects that
`
`the shift code is included in the message data from
`the caller, the detector 9 sends a command to the sig-
`nal processor 8 to cause it to treat message date sub-
`sequently input to the signal processor 8 as the alpha-
`numerically coded data. The signal processor 8 proc-
`esses the paging receiver calling number supplied
`from the collator 6 and the caller's message data in-
`put through the public telephone line 3 and the I10 cir-
`cuit 5 into a paging signal code having a predeter-
`mined format.
`
`A radio paging signal code to be used in the pag-
`ing communication system of this embodiment will be
`described below.
`
`Figs. 2A to 2D are code formats of the CCIR
`(Commite Consuitatif International des Radio-Com-
`munication) radiopaging code No. 1 which is a so-cal-
`led POCSAG (Post Office Code Standardization Ad-
`visory Grou p) code.
`Fig. 2A shows an overall transmission signal for-
`mat. The format inciuding a 576-bits preamble signal
`Aof "101D1O ..." and a plurality of subsequent batch
`data B, C..... The preamble signal causes the paging
`receiver to recognize that the data will be transmitted.
`At the same time. the preamble signal establishes bit
`synchronization.
`Fig. 2B shows a batch data fonnat. The batch
`data format includes a one-word sync code SC at its
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`EP III 342 638 B1
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`beginning. Eight frames CD1 to CD8 each having two
`codewords follow the sync code SC. Each codeword
`has 32 bits. The codewords are classified into ad-
`
`dress and message codewords.
`Figs. 2C and 2D show formats of address and
`message codewords, respectively. Fig. 2C shows the
`address codeword which includes a message flag at
`its beginning. An address bits (address code), func-
`tion bits, BCH parity bits. and an even parity bit follow
`the message flag.
`The message flag indicates whether the code-
`word is an address or message codeword. If the mes-
`sage flag is set at logic “0", it represents an address
`codeword. lfthe message flag is set atlogic "1", it rep-
`resents a message codeword. The address code fol-
`lows the message flag and consists of bit 2 to bit 19.
`The address code corresponds to the calling number.
`Function bits follow the address code. The function
`
`bits have two bits and represent. for example, a dis-
`play form and an alarm form. The function bits repre-
`sent four functions by "00’, '01", "1 D‘, and "11". The
`function infonnation can be input by the caller at the
`key telephone set upon a paging contract between a
`subscriber and a paging service company. Therefore,
`the function information can be used to identify the
`caller. The BCH parity bits are used to correct an error
`in the address code and have bit22 to bit 31. The even
`
`parity bit follows the BCH parity bits. The even parity
`bit represents an odd or even numberof "1 "s from the
`beginning to the end of the address codeword.
`Twenty message bits follow a message flag of
`the message codeword shown in Fig. 2D. The mes-
`sage bits represent message data from a caller. If 4-
`bit coded numeric data are used, the message data
`represent five characters. However, if the 3-bit coded
`alpha-numeric data are used. the message data rep-
`resent 2.5 characters. The data bits are arranged
`such that the least significant bit {LSB) is output first
`every character. That is, if the first character is a char-
`acter of the numeric data, the LSB of the character is
`located at bit 2 of the message codeword, and the
`most significant bit (MSB) thereof is located at bit 5.
`The LSB of an alpha-numeric data character is locat-
`ed at bit 2 of the message codeword. and the MSB is
`located at bit 9. BCH parity bits and an even parity bit
`are added to the message bits in the same manner as
`in the address codeword.
`
`The signal processor 8 shown in Fig. 1 generates
`an address codeword corresponding to the caliing
`number from the coliator 6 and a message codeword
`corresponding to the caller's message data on the ba-
`sis of the commands from the collator 6 and the de-
`
`tector 9, and sends them as a paging signal code hav-
`ing a predetermined format to a transmitter 10. In this
`case, the address codeword is inserted in any one of
`the frames ofthe batch format (Fig. 2B) on the basis
`of the calling number. The message codeword is
`transmitted next to the address codeword. If the mes-
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`sage data from the caller cannot be assigned to one
`message codeword, a plurality of message code-
`words are generated and are continuously transmit-
`ted next to the address codeword. The transmitter 10
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`transmits the paging signal code from the signal proc-
`essor 8 as a radio signal from an antenna 11.
`In this embodiment, the normal data code of the
`message data for the alpha-numeric display paging
`receiver may be a JIS B-bit code (Fig. 3}. A code "FF"
`(hexadecimal notation} which is not defined in the JIS
`8-bit code table is used as a shift code. Therefore,
`when message data including the shift code "FF" is
`input as the message date from the caller to the al-
`pha-numeric display paging receiver. the base station
`outputs the data up to the shift code "FF" as the 8-bit
`code data and the subsequent code as the 4-bit code
`data. The alpha-numeric display paging receiver
`which receives this data processes the reception data
`as the 8-bit code data if it does not detect the shift
`
`code "FF" in the received message data. Otherwise.
`the alpha-numeric display paging receiver processes
`the subsequent data as 4-bit code data.
`A paging receiver which is employed in the radio
`paging communication system according to a first
`embodiment will be described with reference to Figs.
`4 to 11. in this embodiment. the paging receiver in-
`cludes a standard expression memory.
`Referring to Fig. 4. reference numeral 21 denotes
`an antenna for receiving the radio signal transmitted
`from the base station antenna 11 shown in Fig. 1. The
`radio signal received by the antenna 21 is demodulat-
`ed into a digital signal by a receiver22. The digital sig-
`nal is supplied to a decoder 23. The decoder 23 com-
`pares the input calling number {address code) with its
`own calling number stored in an ID-ROM 24 to deter-
`mine whether the input calling number coincides with
`its own calling number. if a noncoincidence is detect-
`ed, the reception operation of the receiver 22 is stop-
`ped. However, if a coincidence is detected, the mes-
`sage data to be received is supplied to a CPU 25.
`The CPU 25 sequentially stores the reception
`data from the decoder 23 in a RAM 26 and causes a
`
`loudspeaker 28 to generate an alarm sound through
`a driver 27. When message data stored in the RAM
`26 is to be displayed, the CPU 25 determines whether
`the shift code "FF" for converting a reading unit from
`eight bits to four bits is present in the data. If no shift
`code "FF" is detected. the CPU 25 determines that
`the data is character data of the normat 8-bit code,
`and pattern data corresponding to the character data
`are read outfrom a character generator 29. The read-
`out pattern data are transferred to a display buffer 30.
`The received message is then displayed on a display
`31 such as an LCD (Liquid Crystal Display).
`When the shift code “FF" is present in the readout
`data, the CPU 25 determines that the data is 4-bit
`code data. The two hexadecimal numbers (i.e., two
`four-bit data) following the shift code "FF" are proc-
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`EP III 342 638 B1
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`essed as a standard expression abbreviation num-
`bers. That is. a standard expression character code
`corresponding to the two four-bit data (i.e., two hex-
`adecimal numbers) is read out from a standard ex-
`pression memory 32. The pattern data corresponding
`to this character code is transferred to the display buf-
`fer 30, and the standard expression message is dis-
`played on the display 31.
`Reference numeral 33 denotes a key input unit
`which includes a readout switch (not shown} for read-
`ing out a received message stored in the RAM 26 and
`a reset switch for stopping an alarm sound and a dis-
`play. Key input signals from the key input unit 33 are
`output to the CPU 25.
`Fig. 5 shows a data format of the RAM 26. As
`shown in Fig. 5. the RAM 26 includes 30 message
`registers D1. D2,... D30 and can store a maximum of30
`messages. All pieces of call information are respec-
`tively stored in registers CA1. CA2...., CA30.
`The call information is the function information as
`
`previously mentioned. When a plurality of calling
`numbers are assigned to a single receiver, infon'na-
`tion representing a correspondence between calling
`and a specific one ofthe calling number can be also
`included in the call information. Atthe time of calling,
`different alarm sound, e.g., different melodies are
`generated based on different pieces of call infonna-
`tion. and they are stored in the registers CA1 to Ciao.
`These pieces of call information are simultane-
`ously displayed during the display of the received
`message (to be described later). Even after the aiarm
`sound is stopped, the caliee can confirm who is call-
`ing. i.e., he knows a correspondence between caliing
`and a specific one of the calling numbers, and the
`content of the function information by monitoring the
`call information. An 8-sec timer counter T1 is a timer
`for counting an alarm time of the alarm sound. A 30-
`sec timer counter T2 is a timer for counting a 30-sec
`display period. Adisplay mode flag F1 is a flag for de-
`termining whether the message data is being dis-
`played. During the display. the flag F1 is set at logic
`"1". An alarming flag F2 determines whether the alarm
`sound is being produced. During generation of the
`alarm sound, the alarming flag F2 is set at logic "1".
`The RAM 26 also includes a display pointer P which
`represents an address of message register storing
`the message data to be displayed. and a memory
`counter MC for storing the number of messages stor-
`ed in the message registers D1 to D39.
`Fig. 6 is a table showing the standard expression
`abbreviation Nos. and the contents of the standard
`
`expressions corresponding to the abbreviation Nos.
`When an abbreviation No., i.e., two hexadecimal dig-
`its, for example. "01’ or "02", is sent to the base sta-
`tion.
`the abbreviation No.
`is transmitted from the
`base station to the receiver. The corresponding stan-
`dard expression as shown in Fig. 6 is displayed on the
`receiver.
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`Fig. 7 shows hexadecimal numbers and charac-
`ters which correspond to key input operations when
`the numeric keys "0" to '9", a key "if", and a key "it"
`of the key telephone set are combined to represent
`the hexadecimal numbers ‘'0'’ to "F". As described
`
`above. when the nondefined code "FF" (hexadecimal
`notation} in the JIS 8-bit code table is defined as the
`shift code for shifting the reading unit from the JIS 8-
`bit code to a 4-bit code, the keys "tr" and "4' are se-
`quentially depressed, and the combination of the
`keys and "4" is used twice, thereby inputting the shift
`code "FF". A desired standard expression abbrevia-
`tion number is then input. A code "EE" is also not de-
`fined in the JIS 8-bit code table. In addition, since a
`character "]" corresponding to the 4-bit code "E" is not
`successively input in a non'na| state, the code "EE"
`may be used as a shift code.
`An operation of the receiver having the above ar-
`rangement will be described with reference to flow
`charts in Figs. 8 to 10.
`Fig. 6 is the flow chart showing receiving proc-
`essing when calling is made. When the receiver re-
`ceives a radio signal from the base station and de-
`tects its own caliing number. message data received
`next to the calling number is stored in the first register
`D1 ofthe message registers ofthe RAM 26 in step S1.
`In this case. prior to storage of the received data in the
`register D1, the previous message data stored in the
`RAM 26 are sequentially shifted to the subsequent
`registers. Therefore, the currently received message
`data is stored in the first register D1.and the second
`newest message data is stored in the second register
`D2. In this manner, the messages data are stored in
`the registers in accordance with the reception time or-
`der. In step 82. the count value of memory counter
`MC is incremented by "1". When the message data
`are stored in all the registers D1 to D30. this increment
`processing is not performed. The alarming ftag F2 is
`set to start generation of an alarm sound (step 33). At
`the same time, the timer counter T1 for counting the
`8-sec alarm time is cleared and then started (step
`S4).
`
`when alarming is started, the CPU 25 determi-
`nes whether the display mode flag F1 is set, i.e., the
`message data is being displayed (step 85). If the dis-
`play flag F1 is set at logic "0", the flow advances to
`step S6 to display a message "Page is made." In step
`57, the CPU 25 determines whether 6 seconds have
`elapsed. If No in step 87. the flow advances to step
`S8 to determine whether the reset switch is turned on.
`
`If N0 in step 88. the flow returns to step S7. The op-
`erations in steps S7 and S8 are repeated to produce
`the a|an'n sound for 8 seconds.
`
`However, if YES in step S8, i.e., the CPU 25 de-
`termines that the reset switch is operated. or if YES
`in step S7. i.e.. the CPU 25 determines that 8 seconds
`have elapsed. the flow advances to step S9 to stop
`the display. in addition, the aiarm sound is stopped.
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`and the alarming flag F2 is reset (step S19). The op-
`eration of the timer counter T. is also stopped (step
`811).
`When the CPU 25 determines in step S5 that the
`display mode flag F1 is set at logic "1", i.e., the user
`is called while the message data stored in the RAM
`is displayed. the flow advances to step 812. The dis-
`play pointer P which represents a memory address of
`the displayed message is incremented by one.
`The display pointer P is incremented due to the
`following reason. The currently received data is stor-
`ed in the first message register D1 upon reception the
`incoming call, and the previous data is shifted by one
`address. At the same time. the message No. (ad-
`dress) stored in the display buffer is incremented by
`one, so that the message No. is updated to a new No.
`(step S13). Thereafter,
`the CPU 25 determines
`whether eight seconds have elapsed in the same
`manner as in step S7 (step S14) and whether the re-
`set switch is turned on in the same manner as in step
`S8 (step S15). The flow then advances to steps S10
`and S11 to stop alarming and the timer counter T1.
`In step 56. the message "page" is displayed. In-
`stead of this, the message indicated by the received
`message data may be displayed.
`In this case, the
`processing in step S6 is same as the read out data
`processing described in later with reference to Fig. 19.
`When a data readout switch is depressed instead
`of calling. readout processing shown in Fig. 9 is exe-
`cuted. In readout processing, the CPU 25 determines
`in step S21 whether the display mode flag F1 is set at
`logic "1", i.e., the message data is displayed. If the dis-
`play mode flag F1 is reset at logic '0". the switching
`operation is the first readout operation, and the flag
`F, is set at logic "1" (step S22). The display pointer P
`is set at logic "1" (step 523). data processing in step
`S24 is executed.
`
`When the display mode ftag F1 set at logic "1" in
`step S21. this state is obtained upon depression of the
`readout switch again during data readout. In this case.
`the flow advances to step S25. and the display pointer
`P is incremented by "1", thus updating the pointer.
`The CPU 25 determines in step S26 whether the val-
`ue ofthe display pointer P is Iargerthan the count val-
`ue of the memory counter MC. i.e., the number of stor-
`ed messages. If NO in step S26. i.e., if P a MC. the
`readout data processing in step S24 is executed.
`However. if YES in step S26, i.e., if P > MC. the flow
`advances to step S23. In step 823. the display pointer
`P is set at 1 , and the address of the pointer returns to
`the beginning.
`The contents of the readout data processing in
`step S24 will be described in detail with reference to
`the flow chart in Fig. 10.
`In step a1 of Fig. 10. the cali information of the
`message register designated by the display pointer P
`is read out. and the display pattern data correspond-
`ing to these codes together with the message No. are
`
`1'0
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`read out from the character generator 29 and stored
`in the display buffer 30. The message data is read as
`alphanumeric code data in units of eight bits {step
`a2). The 8-bitdata is determined to be the shift code
`"FF" representing shifting of the reading unit from
`eight bits to four hits (step a3). Ifthe 8-bit data is de-
`termined to be the shift code "FF". the subsequent
`analysis or reading unit is shifted into 4 bits {step a4).
`The two hexadecimal digits following the shift code
`"FF" are recognized as an abbreviation No. of the
`standard expression message. and the character
`code corresponding to the abbreviation No. is read
`out from the standard expression memory 33. The
`character pattern data corresponding to the character
`code are read out from the character generator 29
`and are transferred to the display buffer 30 (step a5).
`The data following the abbreviation No. are read in
`units of four bits (i.e., each hexadecimal digit) (step
`as). The CPU 25 then determines in step a7 whether
`the message is ended. If N0 in step a7, the flow ad-
`vances to step aa to determine whether two four-bit
`code data “F" successively appear. if YES in step a8.
`the flow returns to step a5, and the two hexadecimal
`digits are processed as a standard expression abbre-
`viation number.
`
`If NO in step a8. i.e.. iftwo code data "F" are not
`successively detected, the pattern data correspond-
`ing to 4-bit code data analyzed first are read out from
`the character generator 29 in step a9. The readout
`pattern data are transferred to the display buffer 30.
`and the flow returns to step a6. When the end of mes-
`sage is determined in step a?, the pattern data cor-
`responding to the immediately preceding analyzed 4-
`bit code data is read outfrom the character generator
`29 and transferred to the display buffer 30. There-
`after. the processing is ended.
`However, if the shift code "FF" is not detennined
`in step a3, theflow advances to step a1 0 to determine
`whether the message is ended. If No in step am, the
`flow advances to step all, and the data are analyzed
`as 8-bit codes. The pattern data corresponding to
`these codes are read out from the character genera-
`tor 29 and transferred to the display buffer 30. There-
`after. the flow returns to step a2.
`Fig. 11 shows key operations. a transmission
`code transmitted from the base station and display
`contents when standard expression abbreviation
`number are input as 4-bit code data from the key tel-
`ephone set.
`As shown in Fig. 11. in order to inputthe standard
`expression corresponding to the abbreviation No.
`"01" at the key telephone set, after a calling number
`of a receiver is input, the keys "s" and "4" are subse-
`quently depressed, and this combination is de-
`pressed twice to input the shift code "FF". Numbers
`"0" and "1" as the standard expression abbreviation
`No. "01" are input. Subsequently, the numeral keys
`"1“ and "B", the keys "v" and "2" corresponding to a
`
`
`
`11
`
`EPlJ342 638 B1
`
`'12
`
`hyphen "-" the numeral keys '0" and "0' and the and
`key "#" are depressed. In the base station, the shift
`code "FF" as the first input data is detected by the de-
`tector 9 in Fig. 1. The base station processes the sub-
`sequent input data as the 4-bit codes. The base sta-
`tion sends out the shift code "FF" for shifting the
`reading unit to four hits from eight bits, the abbrevia-
`tion number "01". numerals "1" and "8", the hyphen
`"D" (hexadecimal notation), and numerals "0" and "D".
`The receiver stores the transmitted data in the
`
`message registers D, to D39. When the receiver de-
`tects the hexadecimal code "FF" the anaiysis or read-
`ing unit is changed from the 8-bit code to the 4-bit
`code. Data "01 " following the shift code "FF" is decod-
`ed as the standard expression abbreviation number,
`and the subsequent data are decoded as 4-bit codes.
`In Example 1, the standard expression corresponding
`to the abbreviation number "01" and data are dis-
`
`1'0
`
`15
`
`played on the display 30 as "Please return before 18 :
`00."
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`Example 2 shows operations, a transmission
`code and dispiay contents when the shift code "FF"
`is transmitted twice to display two different standard
`expressions. Abbreviated numbers "02" and "03" are
`sent after the respective shift codes "FF", thereby
`transmitting two different standard expressions. As a
`result, a message "We made contact with customer.
`Total amount is ¥2,UUO." is displayed on the display
`31.
`
`When readout data display processing is com-
`pleted, the fiow advances to step S2? in Fig. 9. The
`30-sec timer counter T2 is started. The CPU 25 deter-
`mines in step S28 whether 30 seconds have elapsed.
`If NO in step 328, the CPU 25 determine