Abstract:
An image reading/forming device to read/form an image by moving a moving object including either a stimulative flourescent substance sheet on which the image is recorded or a reading/recording section to read/record the image, to the other. The image reading/forming device including a guide member to guide the moving object and a linear motor to move the moving object, the linear motor comprises of a magnet section formed into a shaft-like style having plural magnets extending in the moving direction and a movable coil to straightly moving the moving object. And the linear motor and the guide member are arranged in a row along the direction perpendicular to the moving direction of the moving object.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to a moving device, image reading device and image forming apparatus, and especially, to a moving device by which a generation of speed unevenness of the movement is suppressed and a moving object is smoothly moved, an image reading device and an image forming apparatus.  
       DESCRIPTION OF RELATED ART  
       [0002]     Generally, in various fields, a moving device for linearly moving a moving object is used, by using a DC motor, stepping motor or linear motor, as a driving source. As a device to which such a moving device is applied, for example, there is an image reading device by which, while linearly moving a recording medium in which an image is recorded, as a moving object, by a moving device, an image is read by scanning a laser light in the direction perpendicular to the moving direction, or an image forming apparatus in which, while reciprocally moving a laser irradiation device which is a moving object by a moving device, by irradiating the laser light to a recording medium conveyed in the direction perpendicular to the moving direction of the laser light irradiation device, according to a predetermined image data, and an image is formed.  
         [0003]     Particularly, in a field of the medical care, a radiation image is widely used for a disease diagnosis, and as a method for obtaining this radiation image, a method is conducted by which, after the radiation transmitted through the subject is accumulated and recorded in a stimulative fluorescent substance sheet, and when an excitation light is irradiated by the image reading device, the accumulated and recorded radiation energy is stimulation light-emitted, and when the intensity of this stimulatively emitted light is converted into an electric signal, and according to this electric signal, a visual image is formed in the recording medium by the image forming apparatus.  
         [0004]     In the image reading device and image forming apparatus, used in the field of the medical care as described above, especially, from a viewpoint in which the diagnosis of disease is conducted according to the obtained image, it is required that a very fine image is obtained. In order to obtain the very fine image, because it is necessary that the scanning of the recording medium or the laser light irradiation device is accurately and smoothly conducted, recently, it is proposed that a linear motor is used as a drive source of the moving device for linearly moving the recording medium or the laser light irradiation device.  
         [0005]     As the image forming apparatus in which the linear motor is used as the drive source for the movement of the laser light irradiation device, the image forming apparatus which has a cylindrical support drum rotatable while supporting the recording medium, and the laser light irradiation device which is provided in opposite to this support drum, and while reciprocally moving in the width direction of the recording medium, according to a predetermined image data, irradiates the laser light, and in which the linear motor to move this laser light irradiation device is provided, is well-known (for example, refer to Patent Document 1).  
         [0006]     This image forming apparatus has a holding section which holds the laser light irradiation device which is the moving object, and on almost central portion of the lower surface of this holding section, a movable coil whose sectional shape is L letter-shape constituting a linear motor, is provided, and is arranged in a situation that the movable coil is sandwiched in a magnet section whose section is C letter-shape provided on the lower portion of the holding section, and on the lower portion of both ends of the holding section, the moving device in which guided members by which the movement of the holding member is guided, are respectively provided, is applied.  
         [0007]     [Patent Document 1] Tokkai-hei 11-216921.  
         [0008]     However, in the conventional technology, because the object to be conveyed is conveyed in such a manner that it is arranged so as to be sandwiched in parallel to a linear motor by two guide members, by the sliding-movement resistance of two guides, the delay is generated in a single of them, or depending on the parallel balance at the time of assembling, the vibration is generated and the smooth conveyance can not be conducted, and thereby, the speed unevenness of the object to be conveyed is worsened, and when the stimulative fluorescent plate is scanned by the stimulative excitation light, the image unevenness is generated, and there is a case where the diagnostic image is hindered. Further, because a plurality of guide members are used, there is a problem that the apparatus becomes large and the cost is increased.  
         [0009]     Further, in such a conventional technology, when the rigidity of a horizontal portion and vertical portion of the movable coil are insufficient, a delay is generated in the holding section to the conveying speed of the linear motor, or the vibration is generated and the smooth conveyance can not be conducted, and as a result, the position dislocation is generated in the irradiation of the laser light to the recording medium by the laser light irradiation device held by the holding section, and there is a case where the image unevenness is generated. Accordingly, in order to obtain a fine image, it is necessary that the rigidity of the movable coil is increased, as a result, there is a problem that it is necessary that the movable coil has a dimension more than a predetermined one, and there is a limitation in the size reduction and the cost reduction of the apparatus.  
         [0010]     Further, in the linear motor whose magnet section is c-letter shape, the using efficiency of the magnetic flux is not good, and when the large thrust is wanted to obtain, it is necessary that the magnetic flux density is increased, and as a result, also because the dimension of the magnet section is increased, there is a limitation in the size reduction and the cost reduction of the apparatus.  
         [0011]     In view of such a problem of the conventional technology, the first object of the present invention is to provide an image reading device in which the cost is low and the size is reduced, and by which a fine diagnostic image having no image unevenness is obtained.  
         [0012]     Further, in the conventional technology, an encoder to detect a position of the moving object or the moving speed is provided in the vicinity of the moving device, and according to the detection result by this encoder, the drive of the moving device is appropriately controlled, however, when a linear scale constituting the encoder is not provided in parallel to the moving direction of the laser light irradiation device, or when the linear scale and a sensor section for reading the linear scale are not provided in parallel to each other, because a position of the laser light irradiation device or the moving speed is not exactly detected, it is not correctly controlled as in the case where the speed unevenness is generated in the conveyance by the linear motor of the laser light irradiation device. Accordingly, also in this point, the position dislocation is generated in the irradiation of the laser light to the recording medium, and there is a case where the image unevenness is generated.  
         [0013]     Accordingly, the second object of the present invention is to provide a moving device which can smoothly move the moving object while the generation of the speed unevenness of the movement is prevented, by a small size and low cost device structure, and an image reading device and an image forming apparatus by which a very fine image can be obtained by applying this moving device.  
       SUMMARY OF THE INVENTION  
       [0014]     Above-described problems are solved by one of the following items.  
         [0015]     (1) To solve the above-described problems, an image reading device according to the present invention is characterized in that: in an image reading device by which an image is read by moving the moving object composed of any one of a recording medium in which the image is recorded, and a reading section for reading the image recorded in the recording medium, to the other, a linear motor for straightly moving the moving object, which is composed of a magnet section and movable coil, is provided, and the magnet section is formed into shaft-like extending in the moving direction.  
         [0016]     When the magnet section is formed into shaft-like, and the peripheral surface of the shaft-like magnet section is covered by the movable coil, the movable coil becomes a shape by which the rigidity can be easily obtained. Accordingly, the movable coil is not made larger than a necessary one, and it can be prevented that the delay of the moving speed to the conveying speed of the linear motor is generated, and the vibration is not generated, and the recording medium or reading section is smoothly conveyed.  
         [0017]     Further, when the peripheral surface of the shaft-like magnet section is covered by the moving coil, the using efficiency of the magnetic flux is good, and also when it is wanted that the large thrust is obtained, it is not necessary that the dimension of the magnet section is increased more than it needs.  
         [0018]     (2) In the image reading device written in item 1, it is characterized in that: a guide section for guiding the straight movement of the moving object is provided.  
         [0019]     According to the invention written in item 2, because the guide section for guiding the straight movement of the moving object is provided, the recording medium or the reading section, which is the moving object, is stably conveyed.  
         [0020]     (3) In the image reading device written in item 2, it is characterized in that: the guide section is a singular.  
         [0021]     According to the invention written in item 3, more size-reduction and cost reduction of the whole device can be intended.  
         [0022]     (4) In the image reading device written in any one from item 1 to item 3, it is characterized in that: the movement direction is a vertical direction.  
         [0023]     According to the invention written in item 4, even when the movement direction is a vertical direction, it is prevented that the movable coil is made larger than it needs, and the delay of the moving speed is generated to the conveying speed of the linear motor, and the recording medium or reading section is smoothly conveyed without generation of the vibration.  
         [0024]     Further, when the peripheral surface of the shaft-like magnet section is covered by the movable coil, the using efficiency of the magnetic flux is good, and even when it is wanted that the large thrust is obtained, it is not necessary that the dimension of the magnet section is made larger than it needs.  
         [0025]     (5) In the image reading device written in item 4, it is characterized in that: when the moving body which holds the moving object and moves and a balancing weight for balancing with the moving body, are provided and a connecting member which connects the moving body and the balancing weight is provided, and the moving body is straightly moved by the linear motor, and the balancing weight is relatively moved with the moving body.  
         [0026]     According to the invention written in item 5, when the moving body is risen by the linear motor, because the balancing weight is dropped by the self weight, the thrust by the linear motor can be decreased.  
         [0027]     (6) In the image reading device written in item 5, it is characterized in that: when the drive of linear motor is stopped, it is provided with a brake mechanism for preventing the self-weight dropping of the moving body or balancing weight.  
         [0028]     According to the invention written in item 6, when the drive of linear motor is stopped, it can be prevented that the moving body or balancing weight is dropped by the self-weight.  
         [0029]     (7) In an image forming apparatus by which the image is formed by moving the moving object composed of any one of the recording medium and the recording section for recording the image in the recording medium to the other, it is characterized in that: the linear motor which is composed of the magnet section and the moving coil, and which straightly moves the moving object, is provided, and the magnet section is formed into shaft-like extending in the moving direction.  
         [0030]     According to the invention written in item 7, because the magnet section is shaft-like, it is sufficient when the peripheral surface of the shaft-like magnet section is covered by the movable coil, and the movable coil becomes a shape by which the rigidity can be easily obtained. Accordingly, it is not necessary that the size of movable coil is increased more than it needs, and it can be prevented that the delay is generated in the moving body to the conveying speed of the linear motor, and the recording medium or recording section is smoothly conveyed without generating the vibration.  
         [0031]     Further, when the peripheral surface of the shaft-like magnet section is covered by the movable coil, the using efficiency of the magnetic flux is good, and even when it is wanted that the large thrust is obtained, it comes off without making the dimension of the magnet section larger than it needs.  
         [0032]     (8) In the image forming apparatus written in item 7, it is characterized in that: a guide section for guiding the straight movement of the moving object is provided.  
         [0033]     According to the invention written in item 8, because the guide section for guiding the straight movement of the moving object is provided, the recording medium or recording section, which is the moving object, is stably conveyed.  
         [0034]     (9) In the image forming apparatus written in item 8, it is characterized in that: the guide section is a singular.  
         [0035]     According to the invention written in item 9, more size-reduction and cost reduction of the whole apparatus can be intended.  
         [0036]     (10) In the image forming apparatus written in any one item from item 7 to item 9, it is characterized in that: the moving direction is a vertical direction.  
         [0037]     According to the invention written in item 10, even when the moving direction is a vertical direction, without making the movable coil larger than it needs, it is prevented that the delay is generated in the moving body to the conveying speed of the linear motor, and without the generation of the vibration, the recording medium or recording section is smoothly conveyed.  
         [0038]     Further, when the peripheral surface of the shaft-like magnetic section is covered by the movable coil, the using efficiency of the magnetic flux is good, and even when it is wanted that the large thrust is obtained, it comes off without making the dimension of the magnet section larger than it needs.  
         [0039]     (11) In the image forming apparatus written in item 10, it is characterized in that: the balancing weight for balancing the moving body which holds the moving object and moves, and the balancing weight for balancing the moving body are provided; the connecting member for connecting the moving body and the balancing weight is provided; the moving body is straightly moved by the linear motor; and the balancing weight is relatively moved to the moving body.  
         [0040]     According to the invention written in item 11, when the moving body is risen by the linear motor, because the balancing weight is dropped by the self-weight, the thrust by the linear motor can be decreased.  
         [0041]     (12) In the image forming apparatus written in item 11, it is characterized in that: it is provided with a brake mechanism for preventing the self-weight dropping of the moving body or the balancing weight when the drive of the linear motor is stopped.  
         [0042]     According to the invention written in item 1, when the drive of the linear motor is stopped, it can be prevented that the moving body or the balancing weight is dropped by the self-weight.  
         [0043]     (13) In order to solve the above second problem, the moving device according to the present invention is characterized in that: it is provided with a linear motor structured by a shaft-like magnet section in which a plurality of magnets are arranged, and a movable coil, as a drive source by which the moving object is straightly moved; a guide member for guiding the straight movement of the moving object is provided; and the linear motor and the guide member are arranged in a row along the direction perpendicular to the moving direction of the moving object.  
         [0044]     When the magnet section is structured in such a manner that the magnet section is made shaft-like, and the peripheral surface of the shaft-like magnet section is covered by the movable coil, the movable coil becomes a shape by which the rigidity is easily obtained. Thereby, without making the size of the movable coil larger than it needs, it can be prevented that delay of the moving speed is generated to the conveying speed of the linear motor, and in addition to this, the vibration is decreased and the moving object is smoothly conveyed.  
         [0045]     Further, because the linear motor and the guide member are arranged in a row along the direction perpendicular to the moving direction of the moving object, the balance in the direction perpendicular to the moving direction is good, further, because each of components is provided in close proximity, and the influence of the assembling accuracy of each component is hardly affected, the speed unevenness when the moving operation is conducted, is decreased.  
         [0046]     (14) In the moving device written in item 13, it is characterized in that: in the magnet section, a linear scale constituting an encoder for detecting a position or the moving speed of the moving object is provided; and on one end of the movable coil, a sensor section constituting the encoder and reading the linear scale, is provided.  
         [0047]     According to the invention written in item 14, because the linear motor, guide member and encoder are arranged in a row along the direction perpendicular to the moving direction of the moving object, the balance in the direction perpendicular to the moving direction is good, further, because each of components is provided in close proximity, the influence of the assembling accuracy of each component is hardly affected, therefore, the speed unevenness when the moving operation is conducted, is decreased.  
         [0048]     Further, because the sensor section is provided directly to the movable coil for moving the moving object, a position or moving speed of the moving object is accurately detected.  
         [0049]     (15) In the moving device written in item 13 or item 14, it is characterized in that: a holding section for holding the moving object is provided to the movable coil, and the holding section and the magnet section are arranged at a distance longer than the pitch length of the magnet.  
         [0050]     According to the invention written in item 15, because the holding section and magnet section is arranged at a distance longer than the pitch length of the magnet, and the holding section is hardly affected by the influence of the magnetic field formed of the magnet section, even when the magnetic substance is used in the holding section, when the moving operation is conducted, there is no case where it is attracted to the magnet section, and the speed unevenness is decreased.  
         [0051]     (16) In the moving device written in any one from item 13 to item 15, it is characterized in that: a guided member guided by the guide member is provided to the movable coil; and the guided member and the magnet section are arranged at a distance longer than the pitch length of the magnet.  
         [0052]     According to the invention written in item 16, because the guided member and magnet section is arranged at a distance longer than the pitch of the magnet, and the guided member is hardly affected by the influence of the magnetic field formed of the magnet section, even when the magnetic substance is used in the guided member, when the moving operation is conducted, there is no case where it is attracted to the magnet section, and the speed unevenness is decreased.  
         [0053]     (17) In the moving device written in any one from items 13 to 16, it is characterized in that: the moving direction of the moving object is a vertical direction.  
         [0054]     According to the invention written in item 17, even when the moving operation is conducted in the vertical direction, the speed unevenness is decreased.  
         [0055]     (18) In the moving device written in item 17, it is characterized in that: it has the moving body which holds the moving object and moves against the magnet section; the balancing weight balancing with the moving body, and a connecting member for connecting the holding section to the balancing weight, are provided; the moving body and the balancing weight are arranged in a row along the direction perpendicular to the moving direction of the moving object; and the balancing weight relatively moves to the moving body.  
         [0056]     According to the invention written in item 18, when the moving body is risen by the linear motor, because the balancing weight is dropped by the self-weight, the thrust by a linear motor can be decreased.  
         [0057]     (19) It is characterized in that: as a drive source for straightly moving the moving object, a linear motor structured by a shaft-like magnet section in which a plurality of magnets are arranged, and a movable coil, is provided; a positioning member by which, on a fitting surface of a linear scale for detecting a position or moving speed of the moving object, one side surface of the linear scale is brought into contact with it, and the fitting position is determined, is provided; and on the positioning member, a contact surface of the linear scale is curvedly formed.  
         [0058]     According to the invention written in item 19, because a positioning member for determining the fitting position of the linear scale is provided, one side surface of the linear scale is brought into contact with the positioning member, and when the linear scale is rotated along the curved surface of the positioning member around this contact position, and the fitting position is adjusted so that the linear scale is parallel to the moving direction of the moving object, and it is parallel to the sensor section in the width direction, and it is fitted to the fitting surface. Thereby, a position or moving speed of the moving object is accurately detected, and the speed unevenness is suppressed.  
         [0059]     (20) In the moving device, it is characterized in that: it is provided with a linear motor structured by a shaft-like magnet section in which a plurality of magnets are arranged, and the movable coil; on a fitting surface of a sensor section for reading a linear scale for detecting a position or moving speed of the moving object, a positioning member by which an opposite side surface to the surface opposite to the linear scale of the sensor section is brought into contact with and the fitting position is determined, is provided; and on the positioning member, the contact surface of the sensor section is curvedly formed.  
         [0060]     According to the invention written in item 20, because a positioning member for determining the fitting position of the sensor section is provided, the surface opposite to the surface facing the linear scale of the sensor section, is brought into contact with the positioning member, and when the sensor section is rotated along the curved surface of the positioning member around this contact position, the fitting position is adjusted so that the opposite surface to the linear scale of the sensor section is parallel to the linear scale, and it is fitted to the fitting surface. Thereby, the position or moving speed of the moving object is exactly detected, and the speed unevenness is suppressed.  
         [0061]     (21) In the image reading device, it is characterized in that: in the image reading device by which any one of a recording medium or a reading section by which the image recorded in the recording medium is read, is moved to the other, and the image is read, it is provided with the moving device written in any one from items 13 to 21; and the moving object is any one of the recording medium or the reading section.  
         [0062]     According to the invention written in item 21, because, by the moving device in which the speed unevenness is decreased at the time of moving operation, the recording medium or reading section, which is the moving object, is conveyed, the scanning of the recording medium or reading section is smoothly conducted.  
         [0063]     (22) In the image forming apparatus by which any one of the recording medium and the recording section by which an image is recorded in the recording medium, is moved to the other one, and the image is formed, it is characterized in that: it is provided with the moving device written in any one from items 13 to 20, and the moving object is any one of the recording medium and the recording section.  
         [0064]     According to the invention written in item 22, by the moving device in which the speed unevenness at the time of moving operation is decreased, because the recording medium or the recording section, which is the moving object, is conveyed, the scanning of the recording medium or the recording section is smoothly conducted.  
         [0065]     Following is the effects of each embodiments stated above.  
         [0066]     According to the invention written in item 1, when the movable coil is fixed in the apparatus, it becomes a shape by which the rigidity is easily obtained, and because, without making the movable coil larger than it needs, it is prevented that the delay of the moving speed is generated to the conveying speed of the linear motor, the vibration is not generated, and the recording medium or the reading section is smoothly conveyed, thereby, the very fine image can be obtained by a small-sized and low cost apparatus structure.  
         [0067]     Further, when the peripheral surface of shaft-like magnet section is covered by the movable coil, the using efficiency of the magnetic flux is good, and even when it is wanted that the large thrust is obtained, because it comes off without making the dimension of the magnet section larger than it needs, the size reduction and cost reduction of the apparatus can be intended.  
         [0068]     According to the invention written in item 2, because the guide section for guiding the moving object is provided, and because the recording medium or reading section, which is the moving object, is more smoothly conveyed, further very fine image can be obtained.  
         [0069]     According to the invention written in item 3, because the guide section is singular, more size reduction and cost reduction of the whole apparatus can be intended.  
         [0070]     According to the invention written in item 4, even when the moving direction is a vertical direction, without making the movable coil larger than it needs, it is prevented that the delay of the moving speed is generated to the conveying speed of the linear motor, and because, without the generation of the vibration, the recording medium or reading section is smoothly conveyed, a very fine image can be obtained by the small size and low cost apparatus structure.  
         [0071]     Further, when the peripheral surface of the shaft-like magnet section is covered by the movable coil, the using efficiency of the magnetic flux is good, and even when it is wanted that the large thrust is obtained, because it comes off without making the dimension of the magnet section larger than it needs, the size reduction and cost reduction of the apparatus can be intended.  
         [0072]     According to the invention written in item 5, when the moving body is risen by the linear motor, because the balancing weight is dropped by the self-weight, and the thrust by the linear motor can be decreased, the magnet section and the movable coil can be more size-reduced, thereby, the size reduction and the cost reduction of the apparatus can be intended.  
         [0073]     According to the invention written in item 6, when the drive of the linear motor is stopped, it can be prevented that the moving body or the balancing weight is dropped by the self-weight.  
         [0074]     According to the invention written in item 7, when the movable coil is fixed in the apparatus, it becomes a shape by which the rigidity can be easily obtained, and without making the dimension of the movable coil larger than it needs, it is prevented that the delay of the moving speed is generated to the conveying speed of the linear motor, and because, without the generation of the vibration, the recording medium or the recording section is smoothly conveyed, a very fine image can be obtained by the small sized and low cost apparatus structure.  
         [0075]     Further, when the peripheral surface of the shaft-like magnet section is covered by the movable coil, the using efficiency of the magnetic flux is good, and even when it is wanted that the large thrust is obtained, because it comes off without making the dimension of the magnet section larger than it needs, the size reduction and cost reduction of the apparatus can be intended.  
         [0076]     According to the invention written in item 8, because the guide section for guiding the moving object is provided, and the recording medium or reading section, which is the moving object, is more smoothly conveyed, further very fine image can be obtained.  
         [0077]     According to the invention written in item 9, because the guide section is singular, more size reduction and cost reduction of the whole apparatus can be intended. Also, it becomes possible to suppress speed unevenness generated by the delay of conveyance speed and the vibration caused by the differences of the mechanical sliding resistances of two guide members by introducing one guide member structure.  
         [0078]     According to the invention written in item 10, even when the moving direction is a vertical direction, without making the movable coil larger than it needs, it is prevented that the delay of the moving speed is generated to the conveying speed of the linear motor, and because, without the generation of the vibration, the recording medium or reading section is smoothly conveyed, a very fine image can be obtained by the small size and low cost apparatus structure.  
         [0079]     Further, when the peripheral surface of the shaft-like magnet section is covered by the movable coil, the using efficiency of the magnetic flux is good, and even when it is wanted that the large thrust is obtained, because it comes off without making the dimension of the magnet section larger than it needs, the size reduction and cost reduction of the apparatus can be intended.  
         [0080]     According to the invention written in item 11, when the moving body is risen by the linear motor, because the balancing weight is dropped by the self-weight, and the thrust by the linear motor can be decreased, a size of the magnet section and movable coil can be more reduced, and therefore, the size reduction and cost reduction of the apparatus can be intended.  
         [0081]     According to the invention written in item 12, when the drive of the linear motor is stopped, it can be prevented that the moving body or the balancing weight is dropped by the self-weight.  
         [0082]     According to the invention written in item 13, because the movable coil becomes a shape by which the rigidity is easily obtained, by the small sized and low cost apparatus structure, it is prevented that the delay of the moving speed is generated to the conveying speed of the linear motor, and the vibration is decreased, and the moving object can be smoothly conveyed.  
         [0083]     Further, because the linear motor and the guide member are arranged in a row along the direction perpendicular to the moving direction of the moving object, and the balance in the direction perpendicular to the moving direction is good, further, each of components is proximately provided, the influence of the assembling accuracy of each component is hardly affected, and because the speed unevenness when the moving operation is conducted, is decreased, the moving object can be smoothly moved.  
         [0084]     According to the invention written in item 14, because the linear motor, the guide member and the encoder are arranged in a row along the direction perpendicular to the moving direction of the moving object, and the balance in the direction perpendicular to the moving direction is good, further, because each of components is proximately provided, the influence of the assembling accuracy of each component is hardly affected, and because the speed unevenness when the moving operation is conducted, is decreased, the moving object can be smoothly moved.  
         [0085]     Further, because the sensor section is directly provided to the movable coil for moving the moving object, and a position or the moving speed of the moving object is accurately detected, the speed unevenness of the moving object is suppressed and correctly controlled, and at this result, the moving object can be smoothly moved.  
         [0086]     According to the invention written in item 15, because the holding section is hardly affected by the magnetic field formed of the magnet section, even when the magnetic substance is used in the holding section, when the moving operation is conducted, because there is no case where it is attracted to the magnet section, the speed unevenness of the movement is suppressed, and as this result, the moving object can be smoothly moved.  
         [0087]     According to the invention written in item 16, because the guided member its hardly affected by the magnetic field formed of the magnet section, even when the magnetic substance is used in the guided member, when the moving operation is conducted, because there is no case where it is attracted to the magnet section, the speed unevenness of the movement is suppressed, and as this result, the moving object can be smoothly moved.  
         [0088]     According to the invention written in item 17, even when the moving operation is conducted in the vertical direction, the speed unevenness is decreased, and the moving object can be smoothly moved.  
         [0089]     According to the invention written in item 18, when the moving object is risen by the linear motor, because the balancing weight is dropped by the self-weight, the thrust by the linear motor can be decreased.  
         [0090]     According to the invention written in item 19, because the linear scale is parallel to the moving direction of the moving object, by the positioning member, and is fitted to the fitting surface so that it is parallel in the width direction to the sensor section, and a position or the moving speed of the moving object is correctly detected, the speed unevenness is suppressed, and the moving object can be smoothly moved.  
         [0091]     According to the invention written in item 20, because the sensor section is fitted to the fitting surface so that the opposite surface to the linear scale of the sensor section is parallel to the linear scale, and a position or the moving speed of the moving object is correctly detected, the speed unevenness is suppressed and the moving object can be smoothly moved.  
         [0092]     According to the invention written in item 21, because, by the moving device in which the speed unevenness is decreased at the time of moving operation, the recording medium or reading section, which is the moving object, is conveyed, the scanning of the recording medium or reading section is smoothly conducted, as this result, a very fine image can be obtained.  
         [0093]     According to the invention written in item 22, because, by the moving device in which the speed unevenness is decreased at the time of moving operation, the recording medium or reading and recording section, which is the moving object, is conveyed, the scanning of the recording medium or recording section is smoothly conducted, and as this result, a very fine image can be obtained.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0094]      FIG. 1  is a view showing the structure of an embodiment of an image reading device according to the present invention.  
         [0095]      FIG. 2  is a perspective view showing a conveying mechanism of a linear motor part.  
         [0096]      FIG. 3  is a plan view showing a conveying mechanism of a linear motor part.  
         [0097]      FIG. 4  is a perspective view showing the structure of an encoder in the third embodiment.  
         [0098]      FIG. 5  is a plan view showing the structure of an encoder in the third embodiment.  
         [0099]      FIG. 6  is a view showing the structure of an embodiment of an image forming apparatus according to the present invention.  
         [0100]      FIG. 7  is a perspective view showing a fitting method of a linear scale in the fourth embodiment.  
         [0101]      FIG. 8  is a perspective view showing a fitting method of a sensor section in the fourth embodiment. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0102]     Referring from  FIG. 1  to  FIG. 3 , the first embodiment of the invention will be described below, and referring to  FIG. 4  and  FIG. 5 , the third embodiment will be described, and their operations will be individually described later.  
         [0103]      FIG. 1  is a view in which an embodiment of an image reading device  1  according to the present invention is shown, and on an upper portion of the front side of this image reading device  1 , an insertion inlet  3  into which a cassette  2  in which a stimulative fluorescent substance sheet  14  as a recording medium in which an image is recorded is housed, is inserted, is provided, and on a lower end portion of this insertion inlet  3 , a feeding roller  4  for feeding the cassette  2  into the inside of the image reading device  1  is provided.  
         [0104]     On an upper portion of the front side of the image reading device  1 , and furthermore, on a rear portion of the insertion inlet  3 , a take-out opening  5  for taking out the reading processed cassette  2  is provided, and on the lower end portion of this take-out opening  5 , a sending roller  6  for sending the cassette  2  to the outside of the image reading device  1 , is provided.  
         [0105]     On the lower portion of the front side of the image reading device  1 , a cassette conveying device  7  for conveying the cassette  2  to a predetermined position is rotatably provided by making the lower end a support shaft, by a drive mechanism, not shown, and it can be stopped at each position of a position a corresponding to the insertion inlet  3 , a position b corresponding to the take-out opening  5 , and a position c at which the cassette  2  is almost vertical.  
         [0106]     The cassette conveying device  7  has a box-like cassette supporting section  8  in which the upper surface and the rear surface are opened, and in the cassette supporting section  8 , an elevation table  9  by which the lower end portion of the cassette  2  is supported and which can be risen and fallen is provided.  
         [0107]     Further, in the cassette supporting section  8 , a lock releasing mechanism (not shown) by which the cassette  2  can be separated into a back plate  10  by which the stimulative fluorescent substance sheet  14  is held from the rear surface, and a front plate  11  by which the surface of the stimulative fluorescent substance sheet  14  is covered, is provided. As the lock releasing mechanism, for example, a lock releasing mechanism disclosed in Tokkai 2002-278000, can be used.  
         [0108]     On the rear surface side of the image reading device  1 , a plate-like supporting member  13  extending from a base table  12  to the vertical direction, is provided, and by the supporting member  13 , a moving body  15  which holds the stimulative fluorescent substance sheet  14  and can move in the vertical direction, and a balancing weight  16  balancing with this moving body  15 , are supported relatively in a manner which can go up and down through a connecting member  17 .  
         [0109]     At the center of front surface of the supporting member  13 , as shown in from  FIG. 1  to  FIG. 3 , the first guide rail  18  as a guide member for guiding the moving body  15  in the vertical direction, is provided, and at the center of rear surface, the second guide rail  19  for guiding the balancing weight  16  in the vertical direction, is provided.  
         [0110]     At a position opposite to the first guide rail  18 , a magnet section  20  constituting the linear motor is supported by a supporting piece  21  integrally formed with the supporting member  13  and provided in a extending manner in the vertical direction. The magnet section  20  has, As shown in  FIG. 4 , a permanent magnet  22  whose section is cylindrical, in which mutual N poles or S poles are connected and which is formed into shaft-like, and on the peripheral surface of this permanent magnet  22 , a covering member  23  formed of nonmagnetic material covering the permanent magnet  22 , is provided.  
         [0111]     On the peripheral surface of this covering member  23 , as shown in  FIG. 4  and  FIG. 5 , a flat portion  24  which is flat in a predetermined length in the peripheral direction, is formed extending in the axis direction, and on this flat portion  24 , a linear scale  25  constituting the encoder for detecting a position or the moving speed of the moving body  15  is provided in an extending manner in the axial direction of the magnet section  20 .  
         [0112]     The moving body  15  has, as shown in from  FIG. 1  to  FIG. 3 , a plate-like holding section  26  holding a back plate  10  of the cassette  2  which supports the stimulative fluorescent substance sheet  14 . On the surface of this holding section  26 , a rubber-magnet is provided, and the back plate  10  of the cassette  2  is structured in such a manner that, to the main body formed of synthetic resins, a ferromagnetic substance sheet is adhered, and thereby, the back plate  10  is adhered to the holding section  26  by the magnetic force, and held.  
         [0113]     At a position which is the rear surface center of the holding section  26 , and corresponding to the magnet section  20 , a movable coil  27  constituting the linear motor is provided, and this movable coil  27  has a coil which is cylindrically formed, and this coil is covered by a box-shaped cover member. Then, the linear motor is structured in such a manner that the magnet section  20  penetrates the center of the movable coil  27 .  
         [0114]     At a position which is the upper surface of the movable coil  27 , and opposite to the linear scale  25 , as shown in  FIG. 4  and  FIG. 5 , a sensor section  28  for constituting the encoder and for reading the linear scale  25 , is provided by being supported by the supporting section  29  integrally molded with the movable coil  27 .  
         [0115]     On the surface of the movable coil  27  opposite to a fitting surface of the holding section, as shown in  FIG. 1 , the first guided member  30  whose section is C-shaped, guided by the first guide rail  18 , is integrally provided with the movable coil  27 . The first guided member  30  and the magnet section  20  are arranged at a distance more than a pitch length of the permanent magnet  22 .  
         [0116]     Further, the balancing weight  16  has the second guided member  31  whose section is C-shaped, guided by the second guide rail  19 .  
         [0117]     Hereupon, the moving body  15  represents a movable member to the magnet section  20 , and in the present embodiment, it is structured by the movable coil  27 , holding section  26 , first guided member  30  and sensor section  28 .  
         [0118]     On the front side upper the supporting member  13 , the first pulley  32  is provided, and on the rear side, the second pulley  33  and the third pulley  34  are provided upper and lower it. Across these pulleys  32 ,  33 ,  34 , belt-like connecting member  17  is put. Hereupon, as the connecting member  17 , a steal wire can also be used.  
         [0119]     Further, on the shaft portion of the first pulley  32 , a torque limiter for stopping the rotation operation of the first pulley  32 , one-way clutch, a brake mechanism  35  such as an electromagnetic brake, are provided.  
         [0120]     At a position which is an upper portion of the movable range of the moving body and opposite to the moving body  15 , a reading section  36  for reading the radiation energy which is accumulated and recorded in the stimulative fluorescent substance sheet  14  held by the moving body  15 , is provided.  
         [0121]     The reading section  36  has: a laser light irradiation device  37  by which a laser light L 1  is irradiated on the stimulative fluorescent substance sheet  14  while making the laser light scan in the direction perpendicular to the moving direction of the moving body  15 ; a light guiding plate  38  by which the stimulative emitting light L 2  excited when the laser light L 1  is irradiated on the stimulative fluorescent substance sheet  14  by the laser light irradiation device  37 , is guided; a light collecting tube  39  for light-collecting the stimulative emitting light L 2  guided by the light guiding plate  38 ; and a photoelectric converter  41  by which the stimulative emitting light L 2  light-collected by the light collecting tube  39  is converted into an electric signal.  
         [0122]     Below the reading section  36 , an erasing device  40  for irradiating an erasing light on the stimulative fluorescent substance sheet  14  for discharging the radiation energy remained on the stimulative fluorescent substance sheet  14 , after the radiation energy is reading-processed by the reading section  36 , is provided.  
         [0123]     Next, operations of the first embodiment will be described.  
         [0124]     When the reading processing of the image is conducted, the cassette conveying device  7  is made to stand ready for at a psosition a corresponding to the insertion inlet  3 , and in this situation, when the cassette  2  in which the cassette  2  in which the stimulative fluorescent substance sheet  14  in which the radiation image is recorded is housed, is inserted from the insertion inlet  3 , the cassette  2  is sent into the cassette conveying device  7  by the feeding roller  4 . Then, the elevation table  9  is lowered under a condition that the lower end portion of the cassette  2  is supported, the cassette  2  is housed in the cassette conveying device  7 , and when the lock release mechanism is operated, the cassette  2  is in a condition that it can be separated into the front plate  11  and the back plate  10  by which the stimulative fluorescent substance sheet  14  is held.  
         [0125]     After that, the cassette conveying device  7  is moved to a position c at which the cassette  2  is almost vertical. At this time, when the moving body is positioned at the undermost end of movable range, it becomes a condition that the holding section  26  and the back plate  10  of the cassette  2  are opposed to each other, and by the magnetic force, the back plate  10  by which the stimulative fluorescent substance sheet  14  is supported, is attracted to the holding section  26 , and is separated from the front plate  11  and under the condition that the surface of the stimulative fluorescent substance sheet  14  is exposed, it is held by the holding section  26 . Hereupon, the cassette conveying device  7  may be retreated at a position b corresponding to the taking out opening  5  under the condition that the front plate  11  is held by it.  
         [0126]     After that, the linear motor is driven, and the moving body  15  is risen along the first guide rail  18 . Thereby, the stimulative fluorescent substance sheet  14  is conveyed to a position opposite to the reading section  36 , the laser light L 1  is scanned by the laser light irradiation device  37 , the stimulative emitting light L 2  excited by this, is collected into the light collecting tube  39  by being guided by the light guiding plate  38 , and is converted into an electric signal by the photoelectric converter  41 .  
         [0127]     Herein, because the magnet section  20  is formed into shaft-like, the movable coil  27  is formed into a shape in which the cylindrically formed coil is covered by a box-shaped cover member, and into a shape in which the rigidity is high for being fixed on the holding section  26 . Accordingly, without making the movable coil larger than it needs, it can be prevented that the delay is generated in the moving body  15  to the conveying speed of the linear motor, and without generating the vibration, the stimulative fluorescent substance sheet  14  is smoothly conveyed. Further, because, following the rise of the moving body  15 , pulleys  32 ,  33 ,  34  are rotated, and the balancing weight  16  is dropped by the self-weight along the second guide rail  19 , the thrust by the linear motor can be decreased, and the size of the magnet section and the movable coil can be more reduced.  
         [0128]     When the reading processing by the reading section  36  is completed to the lower end portion of the stimulative fluorescent substance sheet  14 , the linear motor is stopped. At this time, the rotation of the first pulley  32  is stopped by the brake mechanism  35 , and the moving body  15  is stopped under a stable condition.  
         [0129]     After that, the linear motor is driven again, and simultaneously when the moving body  15  is lowered along the first guide rail  18 , the erasing light is irradiated to the stimulative fluorescent substance sheet  14  by the erasing device  40 , thereby, the radiation image remained in the stimulative fluorescent substance sheet  14  is erased.  
         [0130]     After that, when the moving body  15  is lowered to the lowermost end of the movable range and stopped, the cassette conveying device  7  is rotated to a position c at which the cassette  2  is almost vertical. Thereby, the lock is conducted under the condition that the back plate  10  and front plate  11  is integrated.  
         [0131]     Then, while the cassette conveying device  7  is rotated to a position b corresponding to the taking out opening  5  by a drive mechanism, not shown, when the cassette  2  is separated from the holding section  26 , the elevation table  9  is risen, and the feeding roller  6  is actuated, the cassette  2  is taken from the taking out opening  5 .  
         [0132]     From the above description, according to the present embodiment, for the purpose of fixing the movable coil  27  on the holding section  26 , it becomes a shape by which the rigidity is easily obtained, and without making the movable coil  27  larger than it needs, it is presented that the delay is generated in the moving body  15  to the conveying speed of the linear motor, and because, without generation of the vibration, the recording medium or recording section is smoothly conveyed, by the small sized and low cost device structure, a very fine image can be obtained.  
         [0133]     Further, because it is structured in such a manner that the shaft-like magnet section  20  penetrates the movable coil  27  which is formed cylindrically, the using efficiency of the magnetic flux is good, and even when it is wanted that the large thrust is obtained, because it comes off without making the dimension of magnet section  20  larger than it needs, the size reduction and cost reduction of the device can be intended.  
         [0134]     Further, when the moving body  15  is risen by the linear motor, because the balancing weight  16  is dropped by the self-weight, the thrust by the linear motor can be decreased, therefore, the size of the magnet section  20  and the movable coil  27  can be reduced, thereby, the size reduction and cost reduction of the device can be intended.  
         [0135]     Next, referring to  FIG. 6 , the second embodiment of the present invention will be described.  
         [0136]      FIG. 6  is a view showing an embodiment of the image forming apparatus  50  according to the present invention, and in this image forming apparatus  50 , an accommodation tray  52  in which a plurality of recording media  51  are hosed in the laminating manner, is provided, and on the upper side of one end portion of this accommodation tray  52 , a taking out device  53  by which the recording media  51  in which the image is to be recorded, are taken one by one from the accommodation tray  52 , is provided.  
         [0137]     Hereupon, as the recording medium  51 , a recording medium  51  which is formed of the first sheet having a color material layer and the second sheet having a base layer, which generates abrasion of the material between the color material layer and the base layer when the laser light is irradiated, and in which the image can be formed when the color material layer is transferred onto the second sheet, is applied.  
         [0138]     On tile lower side portion of this accommodation tray  52 , a cylindrical supporting drum  54  supporting the recording medium  51 , is rotatably arranged, and this supporting drum  54  is rotated by the drum drive mechanism. Further, on the peripheral surface of the supporting drum  54 , a gripper  55   a  for gripping the leading edge portion of the recording medium  51  over all width, and a gripper  55   b  for gripping the trailing edge portion of the recording medium  51  over all width, are provided in an extending manner in the shaft direction of the supporting drum  54 .  
         [0139]     On the side portion of the supporting drum  54 , a driven roller  56  which is driven-rotated in a slidingly contacted manner with the supporting drum  54 , is provided in a contactable and separable manner to the supporting drum  54 .  
         [0140]     In the upper portion of the image forming apparatus  50 , a delivery tray  57  for delivering the recording medium  51  in which the image is recorded, is provided.  
         [0141]     Inside the image forming apparatus  50 , a conveying path by which the recording medium  51  supplied from the accommodation tray  52  is conveyed to the upper portion of the peripheral surface of the supporting drum  54 , and after the recording medium  51  is conveyed along the peripheral surface of the supporting drum  54 , it is delivered from the upper portion of the peripheral surface of the supporting drum  54  to the delivery tray  57 , is provided. At predetermined positions of this conveying path, a plurality of pairs of conveying rollers  58  for conveying the recording medium  51  in the conveying direction are provided.  
         [0142]     On the side portion of the peripheral surface of the supporting drum  54 , a laser light irradiation device  59  as the recording section by which the laser light is irradiated to the recording medium  51  supported by the supporting drum  54 , is provided, and in the lower portion of the laser light irradiation device  59 , a moving body  80  by which the laser light irradiation device  59  is held and is reciprocally movable in the direction perpendicular to the conveying direction of the recording medium  51  by the linear motor, is provided.  
         [0143]     In the lower portion of the moving body  80 , a plate-like supporting member  61  extending in the direction perpendicular to the conveying direction of the recording medium  51 , is provided, and at almost center of the upper surface of this supporting member, a guide rail  62  as a guiding section for guiding the moving body  80  in the width direction of the recording medium  51 , is provided.  
         [0144]     The moving body  80  has a plate-like holding section  60  for holding the laser light irradiation device  59 . On the rear surface of this holding section  60 , a fitting member  69  is provided, and on the surface opposite to the holding section fitting surface of this fitting member  69 , a guided member  55  whose section is a c-shape, which is guided by the guide rail  62 , is integrally provided with the fitting member  69 .  
         [0145]     On the one side of the fitting member  69 , a magnet section  63  constituting a linear motor, is supported by a supporting piece  74  integrally formed with a supporting member  61 , and is provided extending in the direction perpendicular to the conveying direction of the recording medium  51 . The magnet section  63  is structured in such a manner that a plurality of mutual N poles or S poles of the permanent magnet whose section is circular, are connected, and is formed into shaft-like.  
         [0146]     On the one hand, on the side portion of the fitting member  69 , a movable coil  65  constituting the linear motor is provided. The movable coil  65  has a coil formed cylindrically, and the coil is covered by a box-like cover member. Then, the linear motor is structured in such a manner that the magnet section  63  penetrates the center of the movable coil  65 .  
         [0147]     On the upper surface of the supporting member  61  and on the opposite side to the magnet section  63  with the guide rail  62  between them, a linear scale  66  constituting the encoder for detecting a position or moving speed of the moving body  80 , is provided extending in the width direction of the recording medium  51 . Further, on the position opposite to the linear scale  66  of the holding section  60 , a sensor section  68  which structures the encoder and reads the linear scale  66 , is provided.  
         [0148]     On the downstream side of the conveying path from the supporting drum  54 , a peeling device  71  by which the first sheet and the second sheet of the recording media  51  exposed by the laser light irradiation device  59  are peeled, is provided, and lower the delivery tray  57 , a collecting roller  72  by which the first sheet peeled from the second sheet by the peeling device  71  is wound and collected, is provided. Further, on the downstream side of the conveying path from the peeling device  71 , a delivery roller  73  for delivering the second sheet on which the image is formed onto the delivery tray  57 , is provided.  
         [0149]     Next, operations of the second embodiment will be described.  
         [0150]     When the image information is sent to the image forming apparatus  50 , the taking out device is actuated, and takes out the uppermost recording medium  51  housed in the accommodation tray  52 , and the conveying roller  58  is rotated, and conveys this taken out recording medium  51 .  
         [0151]     When the recording medium  51  is arrived in the vicinity of the peripheral surface of the upper portion of the supporting drum  54 , the supporting drum  54  is rotated clockwise in  FIG. 6 , under the condition that the leading edge portion of the recording medium  51  is gripped by the gripper  55   a . Following the rotation of the supporting drum  54 , when the gripper  55   a  passes the position of the driven roller  56 , the driven roller  56  is brought into contact with the supporting drum  54 , and the recording medium  51  is held on the peripheral surface of the supporting drum  54 . Then, following the rotation of the supporting drum  54 , the gripper  55   b  is moved to a position of the trailing edge portion of the recording medium  51 , and when the trailing edge portion of the recording medium  51  is gripped, the driven roller  56  is separated from the supporting drum  54 .  
         [0152]     After that, the supporting drum  54  is rotated in the opposite direction to the clockwise direction in  FIG. 6 , when, following the rotation of the supporting drum  54 , the recording medium  51  is sent to the position of the laser light irradiation device  59 , according to the image information, the laser light is irradiated to the recording medium  51  by the laser light irradiation device  59 . At this time, following the reciprocal movement of the moving body  80  in the direction perpendicular to the conveying direction of the recording medium  51  by the drive of linear motor, the laser light is scanned to the recording medium  51 .  
         [0153]     Herein, because the magnet section  63  is formed into shaft-like, the movable coil  65  is a shape in which the cylindrically formed coil is covered by a box-like cover member, and for fixing it to the holding section  60 , it is the shape in which the rigidity is high. Accordingly, without making the movable coil larger than it needs, it can be prevented that the delay is generated in the moving body  80  to the conveying speed of the linear motor, and without the generation of the vibration, the laser light irradiation device  59  can smoothly scan.  
         [0154]     When irradiation of the laser light by the laser light irradiation device  59  is completed, the recording medium  51  is conveyed by the conveying roller  58  along the conveying path.  
         [0155]     When the recording medium  51  is conveyed to a position of the peeling device  71 , it is peeled into the first sheet and the second sheet by the peeling device  71 . Then, the first sheet is collected by the collecting roller  72 , the second sheet is delivered to the delivery tray  57  by the conveying roller  58  and the delivery roller  73 .  
         [0156]     From the above-description, according to the present embodiment, the movable coil  65  becomes a shape in which the rigidity is easily obtained when it is fixed to the holding section  60 , and without making the movable coil  65  larger than it needs, it is prevented that the delay is generated in the moving body  80  to the conveying speed of the linear motor, and because, without generation of the vibration, the laser light irradiation device  59  is smoothly conveyed, by the small sized and low cost device structure, a very fine image can be obtained.  
         [0157]     Further, because it is structured in such a manner that the shaft-like magnet section  63  penetrates the cylindrically formed movable coil  65 , the using efficiency of the magnetic flux is good, and even when it is wanted that the large thrust is obtained, because it comes off without making the dimension of the magnet section  63  larger than it needs, the size reduction and cost reduction of the device can be intended.  
         [0158]     Next, operations of the third embodiment will be described.  
         [0159]     When reading processing of the image is conducted, the cassette conveying device  7  is made standby at a position a corresponding to the insertion inlet  3 , and under this condition, when the cassette  2  in which the stimulative fluorescent substance sheet  14  in which the radiation image is recorded, is accommodated is inserted from the insertion inlet  3 , by the feeding roller- 4 , the cassette  2  is sent into the cassette conveying device  7 . Then, the elevation table  9  is lowered under a condition that the lower end portion of the cassette  2  is supported, and the cassette  2  is housed in the cassette conveying device  7 , and when the lock releasing mechanism is operated, the cassette  2  becomes a situation that it can be separated into the front plate  11  and the back plate  10  holding the stimulative fluorescent substance sheet  14 .  
         [0160]     After that, the cassette conveying device  7  is made to be moved to a position c at which the cassette  2  is almost vertical. At this time, when the moving body  15  is made to be positioned at the lowermost end of the movable range, it becomes a situation that the moving body  15  is opposite to the back plate  10  of the cassette  2 , and by the magnetic force, the back plate  10  supporting the stimulative fluorescent substance sheet  14  is attracted to the moving body  15 , separated from the front plate  11 , and held by the moving body  15  under a condition that the surface of the stimulative fluorescent substance sheet  14  is exposed. Hereupon, it is allowable when the cassette conveying device  7  is retreated to a position b corresponding to the taking out opening  5  under a condition that the front plate  11  is made to be held.  
         [0161]     After that, the linear motor is driven and the moving body  15  is risen along the first guide rail  18 . When the stimulative fluorescent substance sheet  14  is conveyed to a position opposite to the reading section  36 , the laser light L 1  is scanned by the laser light irradiation device  37 , and the stimulative emitting light L 2  excited thereby, is guided by a light guiding plate  38  and light-collected into the light collecting tube  39 , and converted into an electric signal by the photoelectric converter  41 .  
         [0162]     Herein, because the magnet section  20 , movable coil  27 , guide rails  18 ,  19  and guided members  30 ,  31  are arranged in a row at the center of the holding section  26 , and the linear scale  25  is provided to the magnet section  20  and the sensor section  28  is provided to the movable coil  27 , the balance in the horizontal direction is good, and because each of components is arranged in close proximity and the influence of assembling accuracy of each component is hardly affected, the speed unevenness to the moving body  15  is decreased, and the stimulative fluorescent substance sheet  14  is smoothly conveyed.  
         [0163]     Further, because the magnet section  20  is shaft-like, the movable coil  27  is a shape in which a cylindrical coil is covered by a box-like case member, and because it is a shape in which the rigidity is easily obtained when it is fixed to the holding section  26 , the speed unevenness at the time of movement is more decreased.  
         [0164]     Further, because the sensor section  28  is directly provided to the movable coil  27  for moving the moving object, and a position or moving speed of the moving object is accurately detected, the movement of moving object is accurately controlled because the speed unevenness is suppressed, and from this, the moving object can be smoothly moved.  
         [0165]     Further, because the holding section  26  and the first guided member  30  are provided at a distance more than a pitch length of the permanent magnet  22  from the magnet section  20 , the influence of the magnetic field is hardly affected, and there is no case where they are attracted to the magnet section  20  at the time of movement. Therefore, the speed unevenness to the moving body  15  is suppressed and the stimulative fluorescent substance sheet  14  is smoothly conveyed.  
         [0166]     When the reading processing to the lower end portion of the stimulative fluorescent substance sheet  14  by the reading section  36  is completed, the linear motor is stopped. At this time, rotation of the first pulley  32  is stopped by the brake mechanism  35 , and the moving body  15  is stopped under a stable condition.  
         [0167]     After that, the liner motor is driven again, and simultaneously when the moving body  15  is lowered along the first guide rail  18 , the erasing light is irradiated to the stimulative fluorescent substance sheet  14  by the easing device  40 , thereby, the radiation image remained in the stimulative fluorescent substance sheet  14  is erased.  
         [0168]     After that, when the moving body  15  is lowered to the lowermost end of the movable range and stopped, the cassete conveying device  7  is rotated to a position c at which the cassette  2  is almost vertical. Thereby, the lock is conducted under a condition that the back plate  10  and the front plate  11  is integrated.  
         [0169]     Then, while the cassette conveying device  7  is rotated to a position b corresponding to the taking out opening  5  by the drive mechanism, not shown, when the cassette  2  is separated from the holding section  26 , and the elevation table  9  is risen and the feeding roller  6  is actuated, the cassette  2  is taken from the taking out opening  5 .  
         [0170]     From the above-description, according to the present embodiment, because the magnet section  20 , movable coil  27 , guide rails  18 ,  19 , and guided members  30 ,  31  are arranged in a row at the center of the holding section  26 , and the linear scale  25  is provided in the magnet section  20  and the sensor section  28  is provided to the movable coil  27 , the balance in the horizontal direction is good, and further, because each of components is arranged in close proximity, and the influence of assembling accuracy of each component is hardly affected, the speed unevenness to the moving body  15  is decreased and the stimulative fluorescent substance sheet  14  is smoothly conveyed, and as this result, a very fine image can be obtained.  
         [0171]     Hereupon, although each of components is arranged in close proximity, because the holding section  26  and the first guided member  30  are hardly affected by the influence of the magnetic field formed of the magnet section  20 , the holding section  26  and the first guided member  30  are not attracted to the magnet section  20  at the time of movement, and the speed unevenness is suppressed.  
         [0172]     Further, because the sensor section  28  is directly provided to the movable coil  27  for moving the moving object and a position or moving speed of the moving object is accurately detected, and also because the speed unevenness of the moving object is suppressed and exactly controlled, a very fine image can be obtained.  
         [0173]     Next, referring from  FIG. 6  to  FIG. 8 , the fourth embodiment of the present invention will be described.  
         [0174]      FIG. 6  is a view showing an embodiment of an image forming apparatus  50  according to the present invention, and in the image forming apparatus  50 , an accommodation tray  52  in which a plurality of recording media  51  are laminated and accommodated, is provided, and on the upper side of one end portion of this accommodation tray  52 , a taking out device  53  by which the recording media  51  in which images are to be recorded, are taken from the accommodation tray  52  one sheet by one sheet, is provided.  
         [0175]     Hereupon, as the recording medium  51 , a recording medium  51  which is formed of the first sheet having a color material layer and the second sheet having a base layer, and when the laser light is irradiated, the abrasion of the material is generated between the color material layer and the base layer, and by which the image can be formed, when the color material layer is transferred onto the second sheet, is applied.  
         [0176]     On the lower side portion of this accommodation tray  52 , a cylindrical supporting drum  54  for supporting the recording medium  51 , is rotatably arranged, and it is structured in such a manner that this supporting drum  54  is rotated by the drum drive mechanism. Further, on the peripheral surface of the supporting drum  54 , a gripper  55  for holding the front end portion of the recording medium  51  covering over whole width and a gripper  55   b  for holding the rear end portion of the recording medium  51  covering over whole width are provided extending in the shaft direction of the supporting drum  54 .  
         [0177]     On the side portion of the supporting drum  54 , a driven roller  56  which is slidably contacted with the supporting drum  54  and driven, is provided in a contactable and separable manner to the supporting drum  54 .  
         [0178]     In the upper portion of the image forming apparatus  50 , a delivery tray  57  for delivering the recording medium  51  in which the image is recorded, is provided.  
         [0179]     Inside the image forming apparatus  50 , a conveying path by which the recording medium  51  supplied from the accommodation tray  52  is conveyed to the upper portion of the peripheral surface of the supporting drum  54 , and after the recording medium  51  is conveyed along the peripheral surface of the supporting drum  54 , it is delivered from the upper portion of the peripheral surface of the supporting drum  54  to the delivery tray  57 , is provided. At predetermined positions of this conveying path, a plurality of pairs of conveying rollers  58  for conveying the recording medium  51  in the conveying direction, are provided.  
         [0180]     On the side portion of the peripheral surface of the supporting drum  54 , a laser light irradiation device  59  as a recording section by which the laser light is irradiated to the recording medium  51  supported by the supporting drum  54 , is provided, and in the lower portion of the laser light irradiation device  59 , a holding section  60  by which the laser light irradiation device  59  is held, and which is reciprocally movable in the direction perpendicular to the conveying direction of the recording medium  51  by the linear motor, is provided.  
         [0181]     Below the holding section  60 , a plate-like supporting member  61  which extends in the direction perpendicular to the conveying direction of the recording medium  51 , is provided, and at the center of the upper surface of this supporting member  61 , a guide rail  62  which is a guide member for guiding the reciprocal movement of the holding section  60  in the width direction of the recording medium  51 , is provided.  
         [0182]     At a position opposite to the guide rail  62 , a magnet section  63  constituting the linear motor, is supported by the supporting piece  74  integrally formed with a supporting member  61 , and provided extending in the direction perpendicular to the conveying direction of the recording medium  51 . The magnet section  63  is formed into shaft-like in such a manner that mutual N poles or S poles of a plurality of permanent magnets, not shown, whose section is circular, are connected.  
         [0183]     At a position which is a center of the rear surface of the holding section  60  and corresponding to the magnet section  63 , a movable coil  65  constituting the linear motor is provided, and the movable coil  65  has a cylindrically formed coil and this coil is covered by a box-like cover member. Then, the linear motor is structured in such a manner that the magnet section  63  penetrates the center of the movable coil  65 .  
         [0184]     On the surface opposite to a holding section fitting surface of the movable coil  65 , a guided member  64  whose section is c-shaped, guided by a guide rail  62  is integrally provided with the movable coil  65 . The guided member  64  and the magnet section  63  are arranged at a distance larger than the pitch length of the permanent magnet.  
         [0185]     On a portion which is the upper surface of the supporting member  61  and a side of the guide rail  62 , as shown in  FIG. 6  and  FIG. 7 , when a linear scale  66  constituting the encoder for detecting a position or moving speed of the holding section  60  is fitted to the supporting member  61 , a cylindrical first positioning member  67  with which one side surface of the linear scale  66  is brought into contact, and which determines a fitting position, is provided.  
         [0186]     Further, on the lower surface of the holding section  60 , as shown in  FIG. 6  and  FIG. 8 , a sensor supporting member  69  for supporting a sensor section  68  which structures the encoder and reads the linear scale  66 , is provided, and on one side surface of this sensor supporting member  69 , when the sensor section  68  is fitted, the cylindrical second positioning member  70  with which the surface of opposite side to the opposite surface to the linear scale  66  of the sensor section  68  is brought into contact, and which determines the fitting position, is provided.  
         [0187]     The linear scale  66  is fitted to the supporting member  61  in such a manner that one side surface is brought into contact with the first positioning member  67 , and when the linear scale  66  is rotated along the peripheral surface of the first positioning member  67  by making this contact position as a fulcrum, the fitting position is adjusted so that it is parallel to the guide rail  62  and parallel to the sensor section  68  in the width direction.  
         [0188]     Further, the sensor section  68  is fitted to the sensor supporting member  69  in such a manner that the surface of opposite side to the surface opposite to the linear scale  66  of the sensor section  68  is brought into contact with the second positioning member  70 , and when the sensor section  68  is rotated along the peripheral surface of the second positioning member  70  around this contact position, the fitting position is adjusted so that the opposite surface to linear scale  66  of the sensor section  68  is parallel to the linear scale  66 .  
         [0189]     Hereupon, it is structured in such a manner that, according to the detection result of the encoder, the operation of linear motor is controlled, and the laser light irradiation device  59  is conveyed so that the scanning of laser light by the laser light irradiation device  59  is accurately conducted.  
         [0190]     On the downstream side of the conveying path from the supporting drum  54 , a peeling device  71  to peel the recording medium  51  which is exposed by the laser light irradiation device  59 , into the first sheet and the second sheet, is provided, and lower the delivery tray  57 , a collecting roller  72  by which the first sheet peeled from the second sheet by the peeling device  71  is wound and collected, is provided. Further, on the downstream side of the conveying path from the peeling device  71 , a delivery roller  73  to deliver the second sheet in which the image is formed, to the delivery tray  57 , is provided.  
         [0191]     Next, operations of the fourth embodiment will be described.  
         [0192]     When the image information is sent to the image forming apparatus  50 , the taking out device  53  is actuated, and takes out the uppermost recording medium  51  accommodated in the accommodation tray  52 , rotates the conveying roller  58 , and conveys this taken-out recording medium  51 .  
         [0193]     When the recording medium  51  reaches in the vicinity of upper portion peripheral surface of the supporting drum  54 , the supporting drum  54  is rotated clockwise in  FIG. 6 , by the drum drive mechanism, under the condition that the front end portion of the recording medium  51  is gripped by the gripper  55   a . Following the rotation of the supporting drum  54 , when the gripper  55   a  passes a position of the driven roller  56 , the driven roller  56  comes into contact with the supporting drum  54 , and the recording medium  51  is held by the peripheral surface of the supporting drum  54 . Then, following the rotation of the supporting drum  54 , the gripper  55   b  is moved to a position of the rear end portion of the recording medium  51 , and when it grips the rear end portion of the recording medium  51 , the driven roller  56  is separated from the supporting drum  54 .  
         [0194]     After that, when the supporting drum  54  is rotated in the opposite direction to the clockwise direction in  FIG. 6 , and following the rotation of supporting drum  54 , the recording medium  51  is sent to a position of the laser light irradiation device  59 , according to the image information, the laser light is irradiated to the recording medium  51  by the laser light irradiation device  59 . At this time, following the reciprocal movement of the holding section  60  in the direction perpendicular to the conveying direction of the recording medium  51  by the drive of linear motor, the laser light irradiation device  59  scans the laser light to the recording medium  51 .  
         [0195]     Herein, because the magnet section  63 , movable coil  65 , guide rail  62  and guided member  64  are arranged in a row at the center of the holding section  60 , the balance in the horizontal direction is good, further, because each component is arranged in close proximity, and because the influence of assembling accuracy of each component is hardly affected, the speed unevenness to the holding section  60  is decreased, and the laser light irradiation device  59  is smoothly conveyed.  
         [0196]     Further, because the magnet section  63  is shaft-like, the movable coil  65  has a shape in which the cylindrical coil is covered by a box-like case member, and because it is a shape in which the rigidity is easily obtained, for a purpose that it is fixed on the holding section  60 , the speed unevenness at the time of movement is more decreased.  
         [0197]     Further, because the holding section  60  and guided member  64  are provided at a distance more than the pitch length of the permanent magnet from the magnet section  63 , the influence of the magnetic field is hardly affected, and they are not attracted to the magnet section  63 . Therefore, the speed unevenness to the holding section  60  is suppressed and the laser light irradiation device  59  is smoothly conveyed.  
         [0198]     Further, because the linear scale  66  is fitted to the supporting member  61  in such a manner that it is parallel to the guide rail  62  by the first positioning member  67 , and parallel to the sensor section  68  in the width direction, and the sensor section  68  is fitted to the sensor supporting member  69  in such a manner that the opposite surface to the linear scale of the sensor section  68  is parallel to the linear scale  66  by the second positioning member  70 , a position or the moving speed of the laser light irradiation device  59  is exactly detected, and as this result, the image formation accuracy by the laser light irradiation device  59  is increased.  
         [0199]     When the irradiation of the laser light by the laser light irradiation device  59  is completed, the recording medium  51  is conveyed along the conveying path by the conveying roller  58 .  
         [0200]     When the recording medium  51  is conveyed to a position of the peeling device  71 , it is peeled into the first sheet and the second sheet by the peeling device  71 . Then, the first sheet is collected by the collecting roller  72 , and the second sheet is delivered to the delivery tray  57  by the conveying roller  58  and delivery roller  73 .  
         [0201]     From above, according to the present embodiment, because the magnet section  63 , movable coil  65 , guide rail  62  and guided member  64  are arranged in a row at the center of the holding section  60 , the balance in the direction perpendicular to the moving direction is good, further, because each component is provided in close proximity, thereby, the influence of the assembling accuracy of each component is hardly affected, the speed unevenness to the moving object is decreased and the laser light irradiation device  59  is smoothly conveyed, as this result, a very file image can be obtained.  
         [0202]     Hereupon, although each component is provided in close proximity, because the holding section  60  and guided member  64  are hardly affected by the influence of the magnetic flux formed by the magnet section  63 , and are not attracted to the magnet section  63  at the time of movement, the generation of the speed unevenness is suppressed.  
         [0203]     Further, because the linear scale  66  is fitted to the supporting member  61  in such a manner that it is parallel to the guide rail  62  by the first positioning member  67 , and parallel to the sensor section  68  in the width direction, and because the sensor section  68  is fitted to the sensor fitting member in such a manner that the opposite surface to the linear scale  66  of the sensor section  68  is parallel to the linear scale  66  by the second positioning member  70 , and a position or moving speed of the laser light irradiation device  59  is exactly detected, the image formation accuracy by the laser light irradiation device  59  is increased, and as this result, a very fine image can be obtained.