Abstract: A type of relief engraved doorplate, comprising an inside plate that is composed of a first Bakelite layer and a second Bakelite layer, said first Bakelite layer and second Bakelite layer being composed of coarse wood dust and fine wood powder respectively, the second Bakelite layer enveloping the exterior of the first Bakelite layer before they are subjected to heated compression molding to obtain the relief engraved pattern on the top and bottom panels of the inside plate; and, at least one pair of outside decorative plates, including at least a layer of thin wood plate and a layer of water-resistant paper, the water-resistant paper being glued onto the thin wood plate and put in a compression mold with a pattern that is opposite to that of the inside plate, to obtain a depressed pattern on one side of the outside decorative plate, which is opposite to the relief engraved pattern on the inside plate, and then it is fitted to the top and bottom panels of the inside plate and subjected to compression molding

Abstract: A type of relief engraved doorplate, comprising an inside plate that is composed of a first Bakelite layer and a second Bakelite layer, said first Bakelite layer and second Bakelite layer being composed of coarse wood dust and fine wood powder respectively, the second Bakelite layer enveloping the exterior of the first Bakelite layer before they are subjected to heated compression molding to obtain the relief engraved pattern on the top and bottom panels of the inside plate; and, at least one pair of outside decorative plates, including at least a layer of thin wood plate and a layer of water-resistant paper, the water-resistant paper being glued onto the thin wood plate and put in a compression mold with a pattern that is opposite to that of the inside plate, to obtain a depressed pattern on one side of the outside decorative plate, which is opposite to the relief engraved pattern on the inside plate, and then it is fitted to the top and bottom panels of the inside plate and subjected to compression molding

Abstract: A power generator for a Digital Cassette Cartridge, which is put into a cassette player for playing back the digital audio files stored in the Digital Cassette Cartridge. The cassette player contains a reel shaft for driving the power generator of the Digital Cassette Cartridge. The power generator includes two gears, a magnetic object, a coil and a power supply. The first gear is coaxially engaged with the reel shafts. The second gear rotates as the first gear rotates. The magnetic object is coaxially mounted and is conjointly rotatable with the second gear. The coil produces an alternating current source when the magnetic object rotates. The power supply receives the alternating current and converts the alternating current to a direct current source.