Computer, light pencil, floppy disk, optical disk, computer keyboard, card punch, card reader, printer, disk drive, memory, microcomputer, main frame, mouse, microprocessor, data storage device, bar scanner, read-only storage, central processor, disk drive, data reader, computer plotter, program design device, printer damper, computer data compiler, computer programmed magnetic tape, computer programmed magnetic disk, computer touch input inducer, program cartridge of game player, magnetic cleaning disk of disk device, credit card, cartridge telephone card, bank cashier card, withdrawal card, disk case, dust protective cover for computer, disk arrangement case, keyboard dust protective cover, camera strap, camera equipment box and cover, camera, slide projector, movie projector and its equipment, digital camera, tripod, slide, projecting slide, optical camera, photo copy machine, camera exposure meter, microfilm reader, light box for perspective slide, video tape recorder and its equipment, disc video recorder, optical disk player, movie projector, cutting and connecting device for video tape, recording machine for disk recorder, recording machine for tape recorder, ENC, closed circuit monitor, electronic anti-burglar and motioning camera, recorder, laser disc, TV telescopic mirror, TV and computer eye protective net, TV and computer eye protector, sound speaker, amplifier, sound mixer, microphone, electronic sound recycle device, sound outer case, microphone stand, headphone receiver, film, blanks video tape, record, tape, film disk, film disk case, video tape arrangement case, laser disk, recorder tape, laser disk case, tape arrangement case, laser disk arrangement case, optical disk case, telephone, fax machine, wireless phone, wireless pager, antenna, distributor, oscilloscope, multiplexer, monitor, wave detector, wave enhancer, wave increaser, antenna bracker, modem variable modulator, signal coupler, signal receiver, signal converter, cable wave carrier, satellite navigator, digital to analogue converter, analogue to digital converter, code reading machine, encoder, image tube, color image tube, diode laser, magnetically coded network card, circuit board, interface card, integrated circuit board, printing board, and integrated printing board