Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
230 words
A motor provided with rotational-speed detection means, comprising: a stator; a rotor rotatably provided on said stator; a driving coil provided adjacent to said stator; a driving magnetized portion provided adjacent to said rotor and having N poles and S poles that are alternately magnetized in the circumferential direction at a regular pitch; a rotational-speed detecting magnetized portion provided adjacent to said rotor and having N poles and S poles that are alternately magnetized in the circumferential direction at a regular pitch; and a detecting pattern provided adjacent to said stator in such a manner that it faces said rotational-speed detecting magnetized portion, said detecting pattern, which is formed in a zigzag shape, having radially extending detecting lines, in accordance with a pitch between each of the N poles and each of the S poles of said rotational-speed detecting magnetized portion, wherein an even number of blocks of said detecting patterns having a predetermined number of said detecting lines are provided, and a pair of blocks are displaced from each other in a rotating direction in relation to the arrangement of the N poles and the S poles of said rotational-speed detecting magnetized portion by an amount equal to one pitch between each of the N poles and each of the S poles of said detecting pattern, said motor further comprising means for canceling currents flowing in the respective blocks.
Claim 2
Dependent Claim
230 words
A motor provided with rotational-speed detection means, comprising: a stator; a rotor rotatably provided on said stator; a driving coil provided adjacent to said stator; a driving magnetized portion provided adjacent to said rotor and having N poles and S poles that are alternately magnetized in the circumferential direction at a regular pitch; a rotational-speed detecting magnetized portion provided adjacent to said rotor and having N poles and S poles that are alternately magnetized in the circumferential direction at a regular pitch; and a detecting pattern provided adjacent to said stator in such a manner that it faces said rotational-speed detecting magnetized portion, said detecting pattern, which is formed in a zigzag shape, having radially extending detecting lines, in accordance with a pitch between each of the N poles and each of the S poles of said rotational-speed detecting magnetized portion, wherein an even number of blocks of said detecting patterns having a predetermined number of said detecting lines are provided, and a pair of blocks are displaced from each other in a rotating direction in relation to the arrangement of the N poles and the S poles of said rotational-speed detecting magnetized portion by an amount equal to one pitch between each of the N poles and each of the S poles of said detecting pattern, said motor further comprising means for canceling currents flowing in the respective blocks.
Claim 3
Dependent Claim
49 words
A motor according to claim 1, wherein a first portion between the pair of blocks serves as a ground potential, said motor further comprising addition means for adding a current flowing in said first portion and a current flowing in a second portion placed opposite to said first portion.
Claim 4
Dependent Claim
50 words
A motor according to claim 1, wherein ends of the respective blocks facing in the same direction serve as ground potentials, said motor further comprising subtraction means for canceling a current flowing in said first portion and a current flowing in a second portion placed opposite to said first portion.
Claim 5
Dependent Claim
38 words
A motor according to claim 1, wherein the pair of blocks have the same number of driving coils to which the same phase of driving currents is supplied, said driving coils facing each other in the respective blocks.