Nec Corporation

Nippon Electric Co., Ltd.

Nippon Telegraph and Telephone Corporation

Shinjiro Umetsu

Masahiro Matai

Toshihiro Mori

Koichi Nagata

Seiji Nishikawa

Yutaka Ichikawa

Hiroyuki Yamaguchi

Takashi Oyamada

Yasuhiro Kobayashi

Yoshio Ichikawa

Takashi Oyagi

Toshiyasu Takasugi

Makoto Ichinohe

Kazushige Sakoh

Hiroshi Arakawa

Tatsuaki Sekigawa

Takehiko Tsutsumi

A controller stops the power supply to receiver circuits after the end of a call informing operation. The call informing unit can always be made call informing when the own call number is received. The message signal decoding can always be made. A call informing executing unit causes execution of a call informing operation in response to a power supply start instruction when the memory is storing a decoded message signal which has not yet been displayed. The presence of a decoded message signal remaining without being displayed, thus can be informed to the user.

Radio selective call receiver

A paging receiver capable of writing a paging code in an ID ROM according to a received signal. When no data is present in the ID ROM, an ID ROM checking section generates a no-data signal. A mode set code detecting section generates a detection signal when received a predetermined mode set code. A switch is turned on and off by the user of the paging receiver. The receiver allows data to be written to the ID according to a received data on condition that the switch is turned on with the no-data signal and detection signal being generated.

Paging receiver

A battery pack mounting device for portable radio equipment having a built-in antenna. The device determines a position of a battery pack, which powers the equipment, inserted in a battery pack accommodating portion provided in the equipment. Various constants which determine the antenna characteristic of the equipment are controlled on the basis of the determined position of the battery pack, thereby maintaining the optimum antenna characteristic at all times. When the device is applied to a charging unit which charges a rechargeable battery, the opposite electrodes of the battery are electrically correctly connected to a pair of connecting terminals which are provided in the charging unit and connected to opposite poles of a charging circuit as the battery pack is inserted in a battery chamber defined in the charging unit. Even when the battery pack is placed in the battery chamber upside down, the opposite electrodes of the battery are accurately connected to the connecting terminals of the charging unit.

Device for mounting an electronic part

Portable radio equipment which is thin enough to enhance portability and, yet, has a sufficiently high antenna gain. The equipment has an antenna which is made up of a pair of metal plates located face-to-face, and a short-circuiting member for short-circuiting the metal plates. A circuit board loaded with radio circuitry is interposed between two metal plates with the radio circuitry being connected to the antenna. A capacitor is connected between the metal plates to lower the resonance frequency of the antenna, as needed. A circular cell for powering the equipment is located in a cell receiving portion near the short-circuiting member.

Dual plate antenna

In a radio display pager, each character of a received multi-character message is checked for error. A first message arrival or a first receive message is stored in a temporary memory and thereafter rewritten into one of main memories when the next message or second message arrival is received. The temporary memory stores the most recent message arrival and the main memories store a plurality of like messages, according to their successive order of earlier arrivals. Each of the messages in both memories contain both error-free and error-containing characters. The characters stored in the temporary memory respectively correspond in position to the characters stored in each of the main memories. A comparison is made between each error-free character in the temporary memory and each of the positionally corresponding error-free characters in one of the main memories in order to detect a match and mismatch. If a mismatch is detected, all characters of each main memory are transferred to an adjacent main memory in order to vacate a storage area. Then, all characters in the temporary memory are transferred to the vacated area for display. If a match is detected, it is counted for all characters of the received message. If the count is smaller than a threshold value, all characters of each main memory are transferred to an adjacent main memory in order to vacate a storage area. All characters in the temporary memory are transferred to that vacated area for display. If the count of the matches is greater than the threshold value, all the error-free characters in the temporary memory are transferred to one of the main memories for display.

Radio paging device having circuitry of rewriting a stored message with

A paging receiver having a display prevents the gain of an antenna from being lowered despite that a metal frame which fixes a display in place is located in close proximity to and in parallel with the antenna. A part of the metal frame which is close to the antenna is removed.

Paging receiver with metallic display frame structure increasing antenna

A selective calling receiver with automatic memory storage and turn-on indication is disclosed. When the receiver is placed in the called state by an incoming signal, audible and/or visual indicator signals actuated by the incoming signal are automatically stopped after a predetermined period of time has elapsed and record of the called state is simultaneously kept in a memory integral to the receiver. Indication of the called state is regenerable at a later time by a switching operation. Indication of the called state is stoppable without recording such indication in memory when a manual reset operation is performed before indication of the called state is automatically stopped.

Selective calling receiver with automatic memory storage and turn-on

In a radio paging receiver which is capable of responding to a message signal specific to the receiver and which comprises a display unit (90) and a message processing section (60) for making the display unit display the message signal, the message processing section monitors the message signal to produce a drive signal after reception of the message signal until the message signal is delivered to the display unit. Responsive to the drive signal, a combination of transistors (3 and 2) keeps power supply of a power source 18 to the message processing section as long as the drive signal is produced. Such power supply is carried out regardless of a state of a power supply switch (20). A decoder (40) makes a speaker (80) generate an alarm in response to the drive signal after the power supply switch is put into an off state. The alarm lasts until the switch is put into an on state. The message processing section may comprise a RAM for storing the message signal as a stored signal and another RAM for storing specific information indicating whether or not the stored signal is delivered to the display unit. Alternatively, such specific information may be stored in a memory included in the decoder.

Radio paging receiver having a message protection capability

A pager which is usable in a plurality of service areas is disclosed. The pager includes a radio section for selectively receiving and modulating two or more radio frequencies, and frequency switching means for switching the receive frequency of the radio section when a signal on a predetermined receive frequency fails to be received. Power source control means is provided for cutting down power consumption. The own call signal is switched at the same time as the receive frequency to offer an effect as would be provided by a plurality of pagers. The receive frequency is displayed so that the user may see a particular service area to which his or her own pager belongs.

Pager

In a portable radio device comprising a housing (20), a printed wiring board (11) encased in the housing, and a machine screw (50) for fastening the board to the housing through a tapped and a via hole (17) and (25), the machine screw has head and threaded portions (51) and (52) and an insulating cap (55) of a cylindrical shape covering the head portion and having at least one groove. Preferably, a pair of the grooves (56, 57) are formed parallel to an axis of the machine screw. The head portion may be circular or polygonal in cross section and have at least one screw slot. At least one groove may be formed on an upper end surface of the insulating cap. Alternatively, the machine screw may wholly be made of an insulating material.

Portable radio device for protecting a radio circuit from static

In a pager receiver comprising a display circuit and an ROM, a controller produces a test mode signal indicative of a test mode in which either the display circuit or the ROM is tested. Responsive to the test mode signal, the ROM supplies the display circuit with a succession of display signals which are previously stored therein and representative of all alphanumeric symbols displayed by the display circuit, so as to test the display circuit. Alternatively, all of contents stored in the ROM are successively sent from the ROM to the display circuit in response to the test mode signal on testing the ROM, so as to inspect the contents. The test mode signal may be delivered from a transmitting end to the controller in the form of a radio calling signal or given to the controller by manual operation. The test mode signal may specify more than two sorts of tests.

Pager receiver comprising a memory storing a sequence of information

In a pulse detector of a receiver for use in a digital radio communication system comprising a low pass filter supplied with an input signal, a first resistor and a capacitor which are connected in series between an output terminal of the low pass filter and ground to constitute a longer time constant integrating circuit, a second resistor connected in parallel with the first resistor through a switch controlled by a control input, the first and second resistors and the capacitor constituting a shorter time constant integrating circuit, and a comparator with one input connected to the output of the low pass filter and the other input to a juncture between the first and second resistors and the capacitor, the potential of the juncture being utilized as a reference potential of the comparator, there is provided a switch connected between the juncture and the ground in series with the capacitor. According to this invention, pulse detection can be made more accurately and power can be much more saved than a prior art pulse detecting circuit.

Pulse detecting circuit of receiver for use in digital radio

A portable radio communication device has a presetting circuit which includes a capacitor having a certain discharge time. The device is provided with a power supply switch having three terminals. On the connection of the first two terminals of the switch, power is supplied to the device. On the connection of the second and third terminal, power supply is stopped and a discharge path is provided for the capacitor. Thus when the device is turned ON and then momentarily turned OFF, and ON again, the capacitor discharge time is reduced.

Portable radio communication device having signal processing circuit

A selective calling receiver has a receiver section for receiving and demodulating radio signals. A decoder section, which is connected to the receiver section, operates with first and second levels of power consumption for selectively receiving the demodulated signals and controlling the receiving operation. A voltage converter section is switched off responsive to a signal from the decoder section when the circuit is operational at the first level of power consumption. The voltage converter section is intermittently switched on and off when the circuit is operating, which requires the second level of power consumption. A timer is activating within a predetermined period after the power is switched to the second level.

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Tokyo, Japan

Shinjiro Umetsu