Mitsubishi Denki Kabushiki Kaisha

Nec Corporation

Mitsubishi Denki K.k.

Nec Home Electronics, Inc.

Masanori Mizuno

Shigeo Ueguri

Osamu Nagano

Yoichiro Tabata

Yoshihiro Ueda

Takaji Mizuno

Yoshiaki Katou

Miki Kurosawa

Yoshiaki Kato

Masaharu Moriyasu

Shozui Takeno

Tsukasa Fukushima

Youichiro Tabata

Hirohisa Segawa

Masayuki Kaneko

Motoe Kitani

Akihiko Iwata

Satoshi Nishida

Hirotsugu Komura

Takao Shimizu

Yasuhiko Iwai

Yosuke Takashima

Schichirou Tsuruta

Masaki Fujimoto

Toshio Banba

Takaii Mizuno

Tatsuki Okawa

In a laser beam machining method for a wiring board, a machined portion of the wiring board is irradiated with a pulsed laser beam for a beam irradiation time ranging from about 10 to about 200 &#x3bc;s and with energy density of about 20 J/cmor more, thereby machining the wiring board, for example, drilling for a through-hole and a blind via hole, grooving, and cutting for an outside shape.

Laser beam machining method for wiring board, laser beam machining apparatus for wiring board, and carbonic acid gas laser oscillator for machining wiring board

The present invention relates to a laser beam machine having a laser oscillator, for generating a laser beam; a light path system, including galvano mirrors and an f&thgr; lens that form a light path along which the laser beam emitted by the laser oscillator is guided to an object; and a diffractive optical element, located along the light path leading from the laser oscillator to the galvano mirrors.

Laser beam machine for micro-hole machining

As a scanning device for positioning the irradiation position of the laser beam emitted from a laser oscillator at a position of arbitrary coordinates in the commanded mutually orthogonal X-axis direction and Y-axis direction, two galvanomirrors having mutually orthogonal rotary axes and a scan lens are provided, and the light generated from a printed circuit board irradiated with laser beam is detected by a detector, and approval or rejection of inspection result at each position of coordinates is judged on the basis of the output signal of the detector.

Apparatus for inspecting a printed circuit board

In a laser beam machining method for a wiring board, a machined portion of the wiring board is irradiated with a pulsed laser beam for a beam irradiation time ranging from about 10 to about 200 &mgr;s and with energy density of about 20 J/cm or more, thereby machining the wiring board, for example, drilling for a through-hole and a blind via hole, grooving, and cutting for an outside shape.

In pulse welding apparatus of arc welding or short-circuit transfer type arc welding in which a pulse discharge created on the tip of a wire electrode is utilized to perform welding, when a molten droplet produced on the tip of wire electrode is late to separate from the wire due to variations of welding conditions and external disturbances, the wire-supplying speed at which the wire is supplied to the weld zone changes causing undercut. To prevent this, pulse current supplied to the base metal is divided into a plurality of pulse groups and the average current reaches the maximum peak value at a predetermined time after beginning of outputting the pulses, and the group of pulse currents is of a hill-shape in its envelope in accordance with the separation phenomenon of molten droplet, and the group of pulse currents is arranged to have different pulse period, pulse width, and pulse interval. In sort-circuiting arc welding, the short-circuit and arc are instantly controlled in accordance with the detected arc length or wire-supplying speed. This ensures the separation of the molten droplet and its transfer onto the base metal in regular manner. As a result, the growth and separation of molten droplet is not affected by magnetic blow of arc but is controllable.

Pulse welding apparatus

In pulse welding apparatus of arc welding or short-circuit transfer type arc welding in which a pulse discharge created on the tip of a wire electrode is utilized to perform welding, when a molten droplet produced on the tip of wire electrode is late to separate from the wire due to variations of welding conditions and external disturbances. The wire-supplying speed at which the wire is supplied to the weld zone changes. This causes undercut, i.e., a defect in welding bead-shape that presents adverse effect to welding quality. To prevent this problem, pulse current supplied to the base metal is divided into a plurality of pulse groups and the average current reaches the maximum peak value at a predetermined time after beginning of outputting the pulses, and the group of pulse currents is of a hill-shape in its envelope in accordance with the separation phenomenon of molten droplet, and the group of pulse currents is arranged to have different pulse period, pulse width, and pulse interval. In the sort-circuiting arc welding, the short-circuit and arc are instantly controlled in accordance with the detected arc length or wire-supplying speed.

A pulse welding apparatus using a pulse discharge such as a pulse arc welding apparatus and a short-circuit transfer arc welding apparatus. A pulse current waveform control circuit, which controls the pulse arc current so that a desired pulse arc current is supplied to the arc welding power supply for outputting the pulse arc current to the welding load unit, is constructed such that the optimum welding operation may be performed without having to adjust circuit components and modify circuit design. The pulse current waveform control circuit is in the form of a microcomputerized digital circuit which operates under a program to provide a desired pulse arc current. A modification of the program can provide any desired pulse arc currents without changing circuits. The optimum welding current waveform parameters or a target arc length signal is learned in the first welding stage and stored into a memory. An arc length feedback control or a current waveform control is performed under the control of program on the basis of the optimum welding current waveform parameters or the target arc length signal so as to control the faulty separation of globules when magnetic blow occurs and so as to reduce the variation of arc length due to external disturbances occurring at the welding torch so that improved welding quality is ensured under various environment.

An apparatus for and a method of controlling a laser oscillator for use as a laser source in a machining operation or the like is disclosed. In particular, the present invention compensates for a deviation of an actual input/output characteristic of a laser oscillator from a normal (expected) input/output characteristic due to, for example, aging and the like. The present invention approximates the actual input/output characteristic and stores the characteristic as a pattern in a storage device. In response to a detection of the actual laser output and an external intensity command signal, the present invention refers to the input/output characteristic pattern thus approximated and generates an input intensity command signal for controlling the laser oscillator to accurately produce the desired laser beam intensity irrespective of the deviation between the actual input/output characteristic and the normal characteristic.

Apparatus for and method of controlling the output of a laser source

Pulsed arc welding equipment

Pulsed arc welding apparatus

An automatic music transcription method and system for generating a muscial score from an input acoustic signal. The acoustic signal may include vocal songs, vocal humming, and music from musical instruments. The system comprises means for extracting pitch information and power information from the input acoustic signal, for correcting the pitch information based on the deviation of the acoustic signal relative to an absolute musical scale, for dividing the acoustic signal into a set of single-sound segments using the corrected pitch information, dividing the acoustic signal into a second set of single-sound segments this time using changes in the power information, for dividing the acoustic signal in still greater detail using information contained in both previous segmentations, for associating each segment with a musical interval of an absolute musical scale, and for determining single-sounds segments depending on whether or not the musical intervals of adjacent segments are identical, for determining the key of the acoustic signal, for correcting the placement of the segments on the musical scale of the determined key using the pitch information, for determining the time and tempo of the acoustic signal using this placement, and for compiling musical score data using the determined musical scale, sound length, key, time, and tempo of the acoustic signal.

Method for automatically transcribing music and apparatus therefore

An arc welding power source utilizing welding current from a two-step voltage conversion comprising a first target value setting circuit means for setting a first current target value V.sub.1 corresponding to a desired value of welding current, a current control circuit for controlling the welding current in accordance with the first current target value V.sub.1, a second target value setting circuit means for setting a second current target value V.sub.2 higher than the first current target value for satisfying a predetermined current waveform in response to an abrupt load variation, and a rapid operation current control circuit for controlling the welding current in accordance with the second current target value V.sub.2. Thus, even if the welding load tends to abruptly vary and the welding current tends to largely exceed the first current target value V.sub.1, the welding current is clipped by the second current target value V.sub.2 by the rapid operation current control circuit having a rapid response so as to maintain the actual welding current in the allowable V.sub.1 -V.sub.2 range.

Arc welding power source with response delay compensating control

A consumable electrode type arc welding apparatus in which arcing can be positively started under a variety of welding conditions. A start current detector selects a predetermined limited start current according to the welding conditions. A start current period setting unit sets a start current period, also in accordance with the welding conditions. A start current control circuit supplies the predetermined limited start current to the workpiece and the wire electrode for the predetermined period of time at the start of arcing.

Consumable electrode type arc welding apparatus having a selectable

An arc blowing control method and apparatus for use in a pulse arc welding system for preventing the extinction of the welding arc in the presence of current fluctuations or the like, thus preventing splattering of molten welding material and resulting in a smooth and continuous welding bead. A detection circuit is provided for electrically detecting the occurrence of a so-called stepped leader phenomenon during pulse arc welding and for generating a stepped leader signal accordingly. A switching unit is operated in response to the stepped leader signal for switching from a normal arc signal output to an arc blowing blocking signal output for a predetermined time. An arc blowing blocking circuit operates in response to the arc blowing blocking signal for effecting arc blowing suppression operations.

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Aichi, Japan

Masanori Mizuno