Acoustic frictional resistance comprises a plate having at least one laser-formed hole therethrough. The plate is formed by positioning a plate preferably one having a thickness smaller than one and one-half milimeters alongside a laser and directing the laser beam so that it cuts a hole through the plate. During the process of producing the resistance, the value of the acoustic friction is measured as a pressure drop of a constant air stream or as an expenditure of electrical energy for an electrically excited electroacoustic transducer. This measurement is then used as a variable or as a standard for controlling the process. Advantageously, a coherent beam is emitted by the laser which is deflected by mirror from a horizontal to a vertical direction and focused by means of a lens to work in a contact-free manner on a workpiece supported on a support member such as a movable table. By moving the table in two coordinate directions, a plurality of bores are formed in a pattern in a workpiece. The workpiece may comprise a plate which may be rectangular, circular, annular, etc.
The present invention provides a laser engraver for engraving a pattern on a workpiece. The pattern is established on the workpiece by using a X-Y assembly to move a laser beam in two dimensions relative to the workpiece. The X-Y assembly employs a X proportional-integral-differential (PID) controller and a Y PID to generate control signals for moving the X-Y assembly. The PIDs generate the control signal based upon the current positon of the laser beam and a target position for the laser beam. The current position is provided by encoders operatively attached to motors that, in turn, move mirrors that direct the laser beam to the workpiece. The depth of cut is, preferably, controlled by using the integral of the difference between the position of the laser beam as it is moved by the X-Y assembly and a reference position. Alternatively, proportional control based upon the absolute difference between the position of the laser as it is moved by the X-Y assembly and the reference position can be utilized.
An optical microphone includes a vibrating membrane defining a diaphragm for receiving acoustic signals. An optical element such as a lens is attached for vibrating with the membrane in direct relationship with the acoustic input signals. Fixed fiber optic cables may be placed in alignment with the lens for directing the initial light toward the lens and transmit the directed light from the lens. A single or dual fiber optic geometry may be used with the vibrating lens.
A plurality of holes are drilled with a repetitively pulsed laser. The time between pulses at one drilling location is utilized to drill the other holes. A rotatable mirror controllably directs the beam to the focusing lens. The distance between the mirror and the lens determines whether the drilled holes are parallel or divergent.
A lead frame fabricating method and a lead frame fabricating apparatus are provided which can easily fabricate lead frames of fine pattern at a high speed, can improve dimensional accuracy and quality of the lead frames after the fabrication, and can realize mass-production at a lower cost. To this end, when cutting a metal plate 1101 by irradiation of a laser beam, a laser beam 1011 emitted in the form of pulses and having a circular section is converted by a beam section transformer 1020 into a laser beam 1012 having an elongate elliptic section. The section of the laser beam 1012 is rotated on its optical axis by a beam rotating device 1030 so that the lengthwise direction of the section of the laser beam 1012 is coincident with the lengthwise direction of each of inner leads 1013. An optical axis of a laser beam 1015 is revolved along each of concentric paths 161 to 174 around the original optical axis given when the laser beam 1011 is emitted. Alternatively, a laser beam 3011 emitted in the form of pulses and having a circular section is converted by a beam section transformer 3020 into a laser beam 3012 having an elongate elliptic section. The section of the laser beam 3012 is rotated on its optical axis by a beam rotating device 3030 so that the lengthwise direction of the section of the laser beam 3012 is coincident with the lengthwise direction of each of the inner leads 1013.
A method of manufacturing one or more nozzles for an ink jet printhead initially comprises bonding a nozzle plate to the ink ejection end of the printhead. A mask is then secured in contact with the nozzle plate, the mask having a plurality of apertures each defining a respective nozzle exit. Laser radiation applied to the mask exposes the areas defined by the apertures to ablate the plate material between the nozzle exits on the external surface of the plate and corresponding nozzle inlets on the opposite surface of the plate. The assembly comprising the printhead, plate and mask is rocked during the exposure step to increase the area of the nozzle inlet relative to its outlet. Also, prior to the nozzle formation step, one or more ink troughs may be provided for supplying an external source of ink for each nozzle. The ink troughs, which may be formed using laser ablation techniques similar to those used in the formation of the nozzles, facilitate a continuous, positive flow of ink through the nozzles.
