| 摘要 |
1,198,227. Resistor manufacture; lasers. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 27 May, 1968 [30 May, 1967], No. 25149/68. Headings H1C and H1S. A helical portion of a resistive layer deposited on a blank 1 is removed by the focused energy of a continuous output laser. The resistive layer may consist of carbon or a nickel chromium alloy on a ceramic support. In the apparatus shown, each resistor blank 1 is supplied by compressed air through a flexible tube 5 to chucks 13, 14 which grip terminal caps 4 and are carried on a slide 8. At least one of the chucks is then rotated and the slide simultaneously moved by mechanism 18. A bridge 31 monitors the resistance value and, when required, a device 32 stops the process, removes the resistor from the chucks and feeds in a fresh blank. The process may be stopped by defocusing the laser output 30, tilting a mirror 28 which may be provided in the optical path, switching off the laser power supply, intercepting the beam with an opaque screen or Kerr cell, or, in another construction, by moving the chucks and the blank out of the beam. The laser 20 consists of a closed discharge tube 22 having platinum electrodes 23, 24 and filled with a gas mixture of carbon dioxide nitrogen and at least one of the gases water vapour and helium. The radiation, at a wavelength of 10À6 microns and with a power exceeding 1 watt, is emitted as parallel beam 21 and focused by a lens 29. A plane partially reflecting mirror 26 and a concave mirror 25 form the laser resonator. |
