Nec Corporation

Other

Yutaka Tomiyori

Koji Maeda

Yukio Murata

Motoyoshi Komoda

Hiroshi Takizawa

Michihiro Ohsuge

Shinsuke Ogawa

Shinji Kawamura

Hidetoshi Takenaka

Noriyuki Tsutsumi

Tadashi Eguchi

Shinobu Okuno

When the number of fingers assigned to a branch signal is smaller than the aimed number and there is a path to be added, the search is performed for an unused finger, firstly, and for one of fingers, the number of which is larger than the aimed number and which are assigned to the branch signal, which has the lowest receiving signal level, secondly. When the aimed number of fingers is satisfied and there is a path to be added, an unused finger is used if any and, when there is only an effective finger, the number of fingers assigned to a branch signal is not increased.

CDMA receiver and CDMA receiving method

In a cellular phone set with a backlighted display, a power amplifier is ON/OFF-controlled in a time division fashion for communicating. A backlight source is driven by a backlight driving circuit synchronized with the ON/OFF control of the power amplifier so that the backlight source is turned on and off when the power amplifier is in the OFF condition and the ON condition, respectively. A power supply for the backlight source is switched by a switching signal which is produced by an AND of a light-on signal for the backlight source and an inverted signal of the ON/OFF control signal for the power amplifier.

Digital portable telephone set having backlighted display with reduced

A power supply switching apparatus for electronic equipment including a first control circuit connected to a battery. The first control circuit monitors a power supply voltage of the battery to output a first control signal when the power supply voltage of the battery is lower than a first predetermined voltage. The first control circuit also outputs a second control signal when the power supply voltage of the battery is higher than a second predetermined voltage. A second control circuit monitors whether power is supplied from an external power supply to the electronic equipment, to generate a third control signal when the power is not supplied from the external power supply. The second control circuit generates the third control signal regardless of whether the second control signal is present, when power is supllied from the external power supply. A switching circiut section supplies power from the battery to the internal circuit when the first and third control signals are not present. The switching circuit section disconnects the battery from the internal circuit in response to the first or third control signal.

Power supply switching apparatus with protection function for supplying

A charging circuit charges a nickel-cadmium battery by means of a constant current source. A resistor, diodes and a tantalum capacitor are connected between an output terminal of the charging circuit and a ground potential. A junction between the capacitor and the diode is connected to one input terminal and an output terminal of a comparator and to the output terminal of the charging circuit. The other input terminal of the comparator is supplied with a reference potential. An output signal having a period which depends on a voltage of the battery is generated at the output terminal. The diodes compensate for a variation of the period of the output signal caused by temperature dependent capacitance change of the capacitor.

Charging circuit with battery charge monitor circuit

If, in a clock generator according to the present invention, the first clock is switched to the second clock with a lower frequency, the frequency count circuit counts the frequency of the second clock with using the first clock as reference. The clock switching control means judges whether the frequency of the second clock is stable or not based on the count result from said frequency count circuit and, if it is stable, switches the switching means for clock switching to the second clock.

Clock generator with an automatic frequency change function

Controlled by a signal level produced by a microphone (12), a noise suppressing circuit (25) supplies a first attenuator (16) with a local level which is equal to the signal level and is suppressed to a predetermined output level when the signal level is lower and higher than a predetermined input level. Cooperating with a drive level produced by a second attenuator (17) to drive a loudspeaker (13), the local level makes a comparator unit (21-23) produce a control signal for making the first attenuator give smaller and greater amounts of attenuation to the signal level with the drive level rendered by the second attenuator low and high when positive and negative values are had, respectively, by an input difference equal to the local level less the drive level. Preferably, the local level is suppressed by a level difference had by the signal level above the predetermined input level.

Loudspeaker telephone device comprising a novel noise suppressing circuit

In a switching circuit for use in a mobile telephone device in controllably transmitting a speech signal to a radio transmission unit through an output terminal (312), a first switch (31) is controlled by a control signal which is supplied to a control terminal (32) with a high level and a low level of putting the first switch in a conductive and a non-conductive state when a second switch (36) is put in its off and on states. A capacitor (35) is connected between the control terminal and the output terminal in order to make the switching circuit have a low output impedance when the first switch is put in its off state.

Switching circuit having a reduced output impedance

A cellular telephone includes a speed dialing memory and a current location memory. International access codes respectively identified by corresponding country codes are stored in an access code memory. An indication of the current location of the telephone is stored in the current location memory. A destination address number is retrieved from the speed dialing memory in response to entry of a speed dialing code through a keypad when a call is originated. The country code of the retrieved number is compared with the stored location indication to detect a match or a mismatch. A first decision is made that the originated call is an International call if a mismatch is detected, or a second decision is made that the cell is domestic if a match is detected. In response to the first decision, an international access code is retrieved from the access code memory corresponding to the stored current location indication and appended to the retrieved address number, and in response to the second decision, the country code of the retrieved address number is replaced with a digit '0'.

Mobile unit with speed dialing feature for cellular telephone network

Terminal equipment having transmitting and receiving functions for a vehicle radio telephone system has a function thereof limited to one of a plurality of modes depending on the time zone. The equipment is automatically locked when a predetermined period of time expires after the end of a communication. The area wherein a call can be originated on the equipment is limited to one of local, domestic and international areas on the basis of the time zone. A memory has a plurality of addresses each being loaded with a particular telephone number to allow the single equipment to selectively use a plurality of telephone channels, on the basis of the time zone. A plurality of memories each stores a particular speed call number table or a particular unattended telephone message table, so that the tables are selectively used depending on the time zone. Further, the volume level of an alert tone to be produced on the reception of a call and the illumination for a keyboard and a display are controlled on the basis of the time zone.

Terminal equipment of a vehicle radio telephone system

An adapter for mounting a portable telephone on a vehicle allows either one of a simple handset and a multi-function handset to be used therewith as desired. The adapter does not need a power switch and associated circuitry and, therefore, reduces the overall weight and size of a portable telephone system. When a multi-function handset is used with the adapter, the adapter is switched on and off by a power switch which is provided on the handset. When a simple handset is used with the adapter, the adapter is switched on and off by an ignition switch which is provided on the vehicle. Further, the adapter promotes easy and convenient use of a handset because it automatically adapts itself to both of a multi-function handset and a simple handset.

Growing community of inventors

Tokyo, Japan

Yutaka Tomiyori