摘要:
A stepping motor (1) which has rotor pole teeth (31) disposed with a predetermined pitch (P1) on a rotor (3) and stator pole teeth (22) formed on a stator pole (21) so to oppose the rotor pole teeth (31), wherein the stator poles (21) are provided with n sets of tooth groups (23) consisting of the stator pole teeth (22) in the number of m, a pitch P2 of the stator pole teeth (22) in the tooth groups (23) is in the relation P2≠P1, and a pitch P3 of the tooth groups (23) is in the relations P3≠m·P1 and P3≠m·P2 (where, P1, P2 and P3 denote an electrical angle, and m and n are integers of 2 or more), and a three-phase stepping motor in which the fourth harmonic and the sixth harmonic are decreased.
摘要:
A PM type stepping motor is provided capable of further reducing the higher harmonic component of detent torque. n sets of teeth groups, each consisting of m stator polar teeth, are set for each of an outer yoke and an inner yoke, and the pitch P2 of the stator polar teeth, the pitch P3 of the teeth groups, and the pitch P1 of the N and S poles of permanent magnets are set such that the relationship: P2≠P1, P3≠m·P1, and P3≠m·P2 holds true, where P1, P2 and P3 are electrical angles, and m and n are integers equal to or larger than 2.
摘要:
A stepping motor includes a pair of internally fitted members 103a and 103b, one disposed at each end portion of a stator 101 in an axial direction thereof. Each internally fitted member 103a and 103b includes a first fitted portion 102 internally fitted to an inner peripheral surface of the corresponding end portion of the stator 101. The stator 101 is sandwiched in a radial direction thereof by the first fitted portions 102 and second fitted portions 117 of a pair of brackets 106a and 106b, one externally fitted to the outer peripheral surface of each end portion of the stator 101 in the axial direction thereof. The internally fitted members 103a and 103b and the brackets 106a and 106b are separately formed so that the brackets 106a and 106b can be freely positioned with respective to the respective internally fitted members 103a and 103b in a radial direction thereof.
摘要:
A pulse signal is output from a position detector or the like provided on an object to be driven by the motor as the object to be driven travels, and the commutation of the motor is controlled on the basis of the pulse signal. More specifically, the object to be driven is driven by the motor, so that the travel of the object to be driven is proportional to the rotational amount of the motor, and the rotational state of the motor can be detected from the traveling state of the object to be driven, thus enabling the detection of the position of the rotor. Hence, by controlling the commutation of the motor on the basis of a detection signal from the position detector, a commutation timing can be precisely detected even if the motor is in a low speed zone.
摘要:
A method is provided for detecting a bacterial pathogen in a sample. One step of the method includes obtaining a sample and then subjecting the sample to nested PCR. The nested PCR is conducted in the presence of at least two outer oligonucleotide primers complementary to a target nucleotide sequence of the bacterial pathogen so that a first amplified product is produced. The target nucleotide sequence includes at least a portion of a 16S-23S ribosomal RNA sequence. The first amplified product is subjected to the nested PCR in the presence of at least two inner oligonucleotide primers complementary to the nucleotide sequence of the first amplified product so that a second amplified product is obtained. Detection of the second amplified product indicates the presence of the bacterial pathogen in the sample.
摘要:
A disk storage unit houses a plurality of sheet-like protective sleeves, each for storing a disk therein. Punched apertures are provided in the protective sleeves, to enable them to be bound in a binder type filing implement. An edge of each of the plurality of protective sleeves is removably affixed to a case by means of an adhesive, which can be peeled off, for example. The disk storage unit enables storage of a great number of recording media disks, such as CD's, in a limited space.
摘要:
When a rotor of a brushless motor 1 is at rest, excitation is performed three times such that excitation phase is switched each time an excitation is performed thereby to ensure that the rotor rotates. When the rotor has stopped after the third excitation, a commutation reference point is set at the rest position. A position detector outputs pulses in response to movement of an object driven by the brushless motor. The pulses output from the position detector are monitored and commutation is controlled on the basis of the number of pulses as counted starting from the commutation reference point. For example, the number of pulses output during a period starting from the commutation reference point and ending at a point of time at which commutation should be performed is measured as a predetermined number in advance. When the counted number of pulses with respect to the commutation reference point becomes equal to the above predetermined number, it is determined that a commutation timing has reached, and commutation is performed.
摘要:
A charger capable of reliably and uniformly maintaining a discharging gap formed in the vicinity of a contact portion between a charging member and a photosensitive member. A charging member 101 is arranged by supporting and fixing both ends of a flexible film 102 by means of support members 103 to 105. The film 102 forms a flexible portion oriented downwardly from fixed ends S1, S2. The film 102 is brought into contact with the member 110 to be charged in a state in which an unsupported side of the film 102 is oriented toward the downstream side in the rotating direction of the member 110 to be charged. Then, the film 102 is brought into contact with the member 110 to be charged in a contact area N, and the radius of curvature of the film 102 in a zone P2 located downstream of that zone N in the rotating direction of the member 110 to be charged becomes smaller than the radius of curvature of the film 102 in an upstream zone P1.
摘要:
A contact charge supply device for externally controlling the charges, which are supplied to a member to be charged by bringing a contact member appled with an external voltage into contact with the member to be charged, which at least includes an underlayer, and holds the following inequalitylog (R).gtoreq.log {Rp.times.(Va-Vt)/Vt}+(.alpha.-.beta.).times.log(S/s)+.gamma..times.log (i/I)where .vertline.Va.vertline..gtoreq..vertline.Vt.vertline.,Va (V): voltage applied to a contact member in contact with the member to be charged; I (.mu.A): current flowing from the contact member to the member to be charged; S (cm.sup.2): contact area of the member to be charged and the contact member; R (.OMEGA.): resistance of the contact member when current I (.mu.A) is fed to an area corresponding to the contact area S (cm.sup.2) of the contact member; .gamma.: current dependency of the resistance of the contact member; 1-.beta.: area dependency of the resistance of the contact member; s (cm.sup.2): area of a defective part of the member to be charged; Vt (V): breakdown voltage of the underlayer; i (.mu.A): current flowing into an area of the underlayer corresponding to the contact area S (cm.sup.2) when a voltage, slightly lower than the breakdown voltage Vt (V), is applied to that area; Rp (.OMEGA.): resistance of the underlayer when the current i (.mu.A) flows into the area of the underlayer corresponding to the contact area S (cm.sup.2) when a voltage, slightly lower than the breakdown voltage Vt (V), is applied to that area; 1-.alpha.: area dependency of the resistance of the underlayer.
摘要:
A printer includes a reversal transportation path which transports a paper to which ink ejected from liquid ejecting heads has adhered toward a downstream side in the transportation direction. In the printer, the reversal transportation path is formed between a pair of guiding plates having a substantially circular arc shape along the transportation direction of the paper and opening holes which blow out wind toward the reversal transportation path from a blowing unit are provided on an inner guiding plate of the pair of the guiding plates, which is positioned at the center side of the circular arc shape.