Abstract: A broadband receiver exhibiting reduced interference to a frequency counter caused by a local oscillator.

Abstract: Reception channel information is communicated to the communication target with a communication device having a receiving function. A local oscillation frequency signal of a local oscillator is modulated with a digital modulator into frequency data as reception channel information, a local oscillation frequency signal associated with the oscillation operation of the local oscillator is leaked, the leaked leakage electromagnetic wave is transmitted to a receiver of the communication target disposed at a close distance, and the reception channel information is received with the receiver of the communication target.

Abstract: A device for connecting an external sound generator having a plug and being incorporated in an apparatus having a circuit outputting an electrical sound signal. The external sound generator is, for instance, either one of a headphone having the plug of 3-pole stereophonic type or a earphone having the plug of 2-pole monophonic type. The device comprises a single jack having a first and second plus contacts and a minus contact for receiving the electrical sound signal from the outputting circuit through the first plus contact and for supplying the electrical sound signal to the plug connected to the jack and an impedance element, such as a electric resistor, connected between the first and second plus contacts. The impedance element prevents a short circuit for use of an earphone having a 2-pole monophonic plug.

Abstract: A controller shifts the frequency of the local oscillator with a frequency shift circuit so that as many channels to be scanned as possible will be included within specified bandwidths, detects a desired received signal by scanning each of the specified bandwidths with the shifted frequency, scans each channel within the bandwidth where the desired received signal was detected, and changes the frequency of the local oscillator or shifts the frequency of the local oscillator with the frequency shift circuit so that the desired channel frequency identified above will be at the center of said bandwidth.

Abstract: A power supply switching apparatus for switching power supplies used to all electronic appliance such as a pager and a portable telephone is described. A battery pack includes a battery and is connectable to an external DC power supply. In the battery pack, a power supply connection detecting circuit detects whether or not the external DC power supply is connected to this battery pack, and a switching circuit switches the battery and the external DC power supply. In an appliance housing a voltage is detected by a voltage detecting circuit to judge whether the detected voltage corresponds to the voltage derived from the battery power supply, or the voltage derived from the external DC power supply, and another switching circuit switches the battery power supply and a power stabilizing circuit. Both of these battery pack and appliance housing constitute the power supply switching apparatus.

Abstract: In portable terminal units each of which has a rechargeable battery and a data processing section, one terminal is used as both a terminal for charging the rechargeable battery and a terminal for connecting a data processing unit to an external data processing unit. First protective circuitry protects the data processing unit from a battery charging current and second protective circuitry eliminates loading of the rechargeable battery due to a data voltage and protects the external data processing unit from charging current for the chargeable battery.

Abstract: A method of searching a specified band of frequencies for a plurality of active signal frequency in a scanning receiver is disclosed. In the preferred embodiment, a range of channel memory storage locations are specified and a controller in the scanning receiver repetitively scans the range of frequencies for active signal frequencies and stores a number corresponding to each active signal frequency in one of the storage locations. Upon filling all of the specified storage locations, the search and store operation is terminated.

Abstract: A highspeed scanning type radio receiver is disclosed which prevents an erroneous interruption of a scanning operation caused by high frequency noises produced from a clock oscillator and a local oscillator circuit employed therein. The highspeed scanning type radio receiver includes a highspeed clock oscillator, a lowspeed clock oscillator, and a clock switching circuit for switching these highspeed clock oscillator and lowspeed clock oscillator to be connected to a CPU. Normally, a searching operation is carried out by supplying the highspeed clock to the microcomputer. When a reception signal is detected in a certain channel, the highspeed clock is changed into the lowspeed clock to be supplied to the microcomputer, whereby a reception signal is again detected. When no reception signal is detectable, the microcomputer recognizes that the detection of the reception signal under operation at the highspeed clock is caused by high frequency noises, and commences a searching operation of the next channel.

Abstract: An automatic frequency transfer and storage method is disclosed in a scanning receiver having a channel memory having a plurality of storage locations for storing frequency numbers corresponding to frequencies. In the preferred embodiment, the storage locations are grouped into channel banks. Each storage location is identified with a channel number and each channel bank is identifed with a channel bank identifier. A source channel number and either a destination channel number or destination channel bank identifier are specified. A controller searches the specified channel bank for a clear storage location. In either case, the controller displays the pertinent frequency transfer information and the transfer is executed upon confirmation, and the source storage location is cleared.

Abstract: In a radio receiver for electronically selecting channels by way of the frequency synthesizer system, a highspeed channel scanning operation is realized. A CPU (central processing unit) detects both an SC (squelch control) signal derived from a squelch circuit and an output voltage from a frequency discriminator. The CPU controls data to be supplied to a PLL (phase-locked loop) circuit employed in a frequency synthesizer so as to perform a channel scanning operation scanning three channels concurrently. When the CPU judges that a desirable reception signal is detected based on a change in the SC signals during the concurrent scan operation. This CPU determines at which channel, the scanning operation is stopped among three channels: the central channel of the three channels searched during the concurrent scan operation, a channel higher in frequency than this searched channel by 1 step, and a channel lower in frequency than this searched channel by 1 step.

Abstract: Upon receipt of address data which matches one of a given plurality of capcodes, this pager executes a paging service corresponding to the matching capcode; this pager is characterized in that any capcode or capcodes specified as being invalid are replaced with a capcode or capcodes specified as being valid based on valid/invalid flags each corresponding to respective one of the capcodes.

Abstract: An automatic tuning system in a high-speed scanning radio receiver provided with (a) a noise squelch circuit, first and second detecting circuits, first and second control circuits, a CPU circuit providing PLL data, and a scanning stop function. The squelch circuit generates a first (SP) signal when a decreasing trend in a noise detection voltage becomes lower than a preset reference voltage. The first detecting circuit judges whether or not the SP signal is generated within first predetermined time period (M1).