The present invention relates to method and apparatus of recording data onto a disk recording medium in zoned-CLV mode while adjusting recording speed and recording condition adequately at every speed change point between zones. A mutual twisting phenomenon can be prevented by interacting magnetic force among the plurality of magnets to thereby reduce the rate of defects. A fused portion made of materials of the noble metal chip and the electrode fused together by the laser welding is formed in the joint so that it may continue over at least half a circumference of a contact between the noble metal chip and the electrode without interfaces of welds, thereby enhancing the activity of the fused portion as a thermal stress absorber. Each component in the first entity has at least the trust level of the first entity.