Abstract: There is provided a linear motor in which the number of armature windings can be reduced, and an armature iron core can be readily fixed to a member for supporting the armature iron core. Each of three inductors 1A to 1C is so arranged that a tooth row 7 therein is located on each side thereof in a width direction thereof orthogonal to a moving direction of an armature 3. The three inductors are arranged spaced apart from each other by a predetermined spacing in the width direction. An armature iron core 9 of the armature 3 includes four magnetic pole portions 15A to 15D and three yoke portions 17A to 17, and is constituted by a plurality of electromagnetic steel plates laminated in the moving direction of the armature 3. The four magnetic pole portions 15A to 15D are arranged in parallel and spaced apart from each other by a predetermined spacing so that each of the three inductors 1A to 1C is positioned within the spacing.

Abstract: A linear motor not requiring a yoke structure is provided. A first unit 1 forming a stator is constructed of two permanent magnet rods 11A, 11B. The permanent magnet rods 11A, 11B each have a magnetically permeable shaft 15 and a permanent magnet row 17 having a plurality of permanent magnets 19 so arranged that opposite polarities of their magnetic poles alternatively appear. The permanent magnet row 17 of the permanent magnet rod 11A is arranged with a positional difference of 180° in an electrical angle from the permanent magnet row 17 of the permanent magnet rod 11B. The second unit 3 that constitutes a moving member includes unit cores 21 and winding sets arranged alternatively in an axial direction of the shaft 15. The winding set includes two excitation windings through each of which the permanent magnet rod loosely extends. One excitation winding of the winding set is excited with a phase difference of 180° in an electrical angle from the other excitation winding.

Abstract: A linear motor in which the shape of magnetic pole surfaces of pole teeth located at both ends of a plurality of pole teeth can be easily formed to be suitable for reducing cogging force. Each of magnetic pole surfaces 19a of pole teeth 15A located at both ends of a plurality of pole teeth 15 is constituted by an arc-shaped curved surface that is curved so that a gap from a stator 1 increases with increasing distance from other adjacent pole tooth 15B. Through holes 23A and 23B that extend in the laminating direction of electromagnetic steel plates 10 are formed in the vicinity of the magnetic pole surfaces 19a of the pole teeth 15A. Inside the through holes 23A and 23B, magnetic pieces, which are shorter than the thickness of the electromagnetic steel plates in their laminating direction, are arranged so as to leave spaces at both ends of the through holes 23A and 23B.

Abstract: The present invention has a sheet placing tray on which a sheet is placed, a feeding member for feeding the sheet placed on the sheet placing tray, a first sheet detection unit for detecting presence of the sheet on the sheet placing tray at a first detection position, a second sheet detection unit for detecting presence of the sheet on the sheet placing tray at second detection position disposed on an upstream side of the first detection position in a sheet feeding direction, and a control unit controls the feeding member so as not to perform the sheet feeding operation when the first detection unit is in a state in which the sheet is detected and the second detection unit is in a state in which the sheet is not detected.

Abstract: A linear motor in which the shape of magnetic pole surfaces of pole teeth located at both ends of a plurality of pole teeth can be easily formed to be suitable for reducing cogging force. Each of magnetic pole surfaces 19a of pole teeth 15A located at both ends of a plurality of pole teeth 15 is constituted by an arc-shaped curved surface that is curved so that gap from a stator 1 increases with increasing distance from other adjacent pole tooth 15B. Through holes 23A and 23B that extend in the laminating direction of electromagnetic steel plates 10 are formed in the vicinity of the magnetic pole surfaces 19a of the pole teeth 15A. Inside the through holes 23A and 23B, magnetic pieces, which are shorter than the thickness of the electromagnetic steel plates in their laminating direction, are arranged so as to leave spaces at both ends of the through holes 23A and 23B.

Abstract: A movable assembly used in a cylinder type linear motor is provided which can be manufactured at low cost without requiring a cutting process while preventing its magnetic characteristics from deteriorating. The movable core is constructed of a laminated yoke which is formed of a plurality of electromagnetic steel plates laminated in an axial direction of the first and second direct drive shafts. A plurality of permanent magnets 31 fixed to the laminated yoke 29 are arranged in such a manner that the polarity appearing on the outer surface of the two permanent magnet 31 opposing each other through the laminated yoke 29. The first and second direct drive shafts each have a yoke mounting portion and paired supported portions at both axial ends of the yoke mounting portion. The first and second direct drive shafts are so shaped that the cross section of the yoke mounting portion orthogonal to the axial direction is smaller than that of the supported portions.

Abstract: The present invention provides an image forming apparatus including an apparatus main body having a contact, and an electric component unit mountable and dismountable with respect to the apparatus main body, and wherein the electric component unit has a circuit substrate, and a contact electrically connected to the circuit substrate, and further including a guide portion for guiding a movement of the electric component unit when the electric component unit is mounted to the apparatus main body, and further wherein, when the electric component unit is mounted to the apparatus main body, the contact of the electric component unit is electrically connected to the contact of the apparatus main body by guiding the movement of the electric component unit by means of the guide portion.

Abstract: A developer replenishing apparatus including a developer container having a discharge port for discharging a developer therethrough, a screw for carrying the developer to the discharge port, a drive source for driving the screw, a motive power transmitting device for transmitting motive power from the drive source to the screw, and a rotation amount detecting device for detecting the amount of rotation of a predetermined rotary shaft in the motive power transmitting device, wherein the rotation period of the screw is an integral multiple of the rotation period of the predetermined rotary shaft.

Abstract: The present invention provides an image forming apparatus including an apparatus main body having a contact, and an electric component unit mountable and dismountable with respect to the apparatus main body, and wherein the electric component unit has a circuit substrate, and a contact electrically connected to the circuit substrate, and further including a guide portion for guiding a movement of the electric component unit when the electric component unit is mounted to the apparatus main body, and further wherein, when the electric component unit is mounted to the apparatus main body, the contact of the electric component unit is electrically connected to the contact of the apparatus main body by guiding the movement of the electric component unit by means of the guide portion.

Abstract: A developer replenishing apparatus including a developer container having a discharge port for discharging a developer therethrough, a screw for carrying the developer to the discharge port, a drive source for driving the screw, a motive power transmitting device for transmitting motive power from the drive source to the screw, and a rotation amount detecting device for detecting the amount of rotation of a predetermined rotary shaft in the motive power transmitting device, wherein the rotation period of the screw is an integral multiple of the rotation period of the predetermined rotary shaft.

Abstract: A process cartridge detachably mountable to a main assembly of an image forming apparatus, includes an electrophotographic photosensitive drum having a coupling member at one end thereof. The process cartridge is detachably mountable in a direction of an axis of the electrophotographic photosensitive drum. The cartridge also includes a process device actable on the electrophotographic photosensitive drum, and a projected shaft projected from the coupling member of the electrophotographic photosensitive drum. The projected shaft is engageable with a hole of an engaging member provided in the main assembly.

Abstract: An automatic image quality adjusting device for use in a video signal recording/reproducing apparatus includes a reproducing an head for reproducing FM signal from a magnetic recording medium, an envelop detecting unit for detecting an envelop of the FM signal, and grade detecting unit for detecting a grade of the envelop in accordance with an amplitude of the envelop. A frequency characteristics changing unit is provided for changing the frequency characteristics of a processing signal processed in stages between the reproducing head and a display unit in accordance with to the detected grade. Thus, the image quality is automatically adjusted by changing the frequency characteristics of processing signals in response to the detected grade of the envelope.

Abstract: In the microwave plasma CVD apparatus according to the present invention, magnets are disposed at the outer circumference of the microwave introduction section thereby forming the magnetic field in the same direction as the direction of introducing the microwave to thereby prevent film deposition to the microwave introduction window. By the apparatus according to the present invention: (1) Microwave can be supplied to the inside of the vacuum chamber always under stabilized state, and (2) the maintenance frequency for the microwave introduction window of the microwave CVD apparatus can be increased.