JP4333296B2 - Film transport mechanism - Google Patents

Description

  The present invention relates to a film transport mechanism for feeding and rewinding a film in order to scan a film stored in a cartridge.

  2. Description of the Related Art Photographic processing apparatuses capable of automatically performing processing such as exposure, development, bleach-fixing, and stabilization on photosensitive materials such as photographic paper are known. In recent years, so-called digital exposure, in which a photosensitive material is exposed with light controlled based on digital image data (image signal) obtained by imaging a film with a film scanner having an image sensor such as a CCD sensor, has been put into practical use. ing. By adopting the digital exposure method, various image processing such as color correction, density correction, and sharpening processing can be performed with a high degree of freedom, and quick reprint processing is possible, and color and density reproducibility is also possible. In addition, it is possible to obtain an excellent print with higher resolution and higher resolution.

  A film taken with an APS (Advanced Photo System) camera is generally stored in a cartridge. When the film is subjected to a process such as scanning, the film is removed from the cartridge. It must be sent out once. Here, the film scanner is provided with a film transport mechanism for sending out and rewinding the film stored in the cartridge, and press-canning is performed in the process in which the film is sent out from the cartridge. There is a case where the main scanning is performed in the process in which the toner is rewound into the cartridge. In such a film scanner, the film is often imaged by a linear CCD sensor while being transported at a substantially constant speed by two pairs of film transport rollers arranged so as to sandwich the scanning position.

  In such a film transport mechanism, the spool shaft around which the film in the cartridge is wound is rotated to feed the film front end out of the cartridge, and when the film is transferred to the pair of film transport rollers, between the cartridge and the film transport roller pair. In order to prevent the film from slackening, it is necessary to rotate the spool shaft so that the film transport speed based on the transport force of the pair of film transport rollers is faster than the film feeding speed based on the rotational force of the spool shaft. Conversely, when the film is rewound into the cartridge, the film conveyance speed based on the conveyance force of the film conveyance roller pair is based on the rotational force of the spool shaft so that the film is stored in the cartridge without being loosened. It is necessary to rotate the spool shaft so as to be slower than the rewinding speed. For this purpose, a motor for driving the film transport roller pair and a motor for driving the spool shaft are individually provided, and the respective rotation speeds are controlled independently (see, for example, Patent Document 1).

JP 2003-98604 A (page 3-6, FIG. 1)

  However, since the film transport mechanism has two motors, the motor arrangement space becomes large, so that there is a problem that it is difficult to reduce the size and the manufacturing cost increases. Furthermore, when controlling the rotational speeds of the film transport roller pair and the spool shaft, it is necessary to synchronize the two motors that drive each of them, which causes a problem that the control of these motors becomes complicated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a film transport mechanism that is small in size and can be manufactured at low cost and does not require complicated control.

Means and effects for solving the problems

The film transport mechanism of the present invention includes a spool drive shaft that supports a spool shaft around which a film on which an image is recorded is wound, and the spool that is supported by the spool drive shaft in order to read an image recorded on the film. a conveying roller pair that rotates based on the unwound film from the axis torque transmitted from the sandwich membrane Tsuhara rotary shaft, tension is applied to the film with the rotation of the conveying roller pair of the film feeding direction And a feed state in which the spool drive shaft that rotates in the film feed direction by the tension is idle with respect to the driving shaft, and the rotation of the spool drive shaft and the spool shaft in the film rewind direction. Tension is applied to the film, and torque applied to the spool drive shaft by the tension is applied. The driving shaft capable of selectively taking a rewinding state in which the spool drive shaft is rotated in the film rewinding direction so as not to exceed a predetermined value so as not to affect the film conveyance speed; A rotational force transmitting portion for connecting the spool drive shaft; and a switching mechanism for switching the state of the rotational force transmitting portion between the delivery state and the rewind state. The rotational force transmitting portion includes a first driving gear supported by the driving shaft, a second driving gear supported by the driving shaft, and a rotation-time rotating gear supported by the spool driving shaft. A rewinding rotation gear supported by the spool drive shaft, a first driven rotation gear capable of meshing with both the first drive gear and the sending rotation gear in the delivery state, and the winding A second driven rotating gear capable of meshing with both the second driving gear and the rewinding rotating gear in the return state; Furthermore, the switching mechanism supports the first and second driven rotating gears, and the first driven rotating gear meshes with both the first drive gear and the sending rotation gear. The second driven rotating gear includes a support member that can swing between a rewinding position where the second driven rotating gear meshes with both the second drive gear and the rewinding rotating gear. In addition, the number of teeth of the first driving gear, the sending rotation gear, and the first driven rotating gear is determined so that the transport speed of the film is based on the transport force of the transport roller pair in the feed state. The number of teeth of the second driving gear, the rewinding rotating gear, and the second driven rotating gear is set so as to be faster than the feeding speed of the film based on the rotational force of the shaft. The film transport speed based on the transport force of the transport roller pair in the rewind state is set to be slower than the film rewind speed based on the rotational force of the spool shaft.

  According to this configuration, it is possible to drive both the conveyance roller pair that holds and conveys the film unwound from the spool shaft and the spool shaft around which the film is wound, by a single drive source. At this time, the film unrolled from the spool shaft is smoothly transported without being loosened while being held between the pair of transport rollers, so that the film is hardly damaged by applying excessive tension to the film. No. Further, the film rewound onto the spool shaft is wound around the spool shaft without being loosened, and the change in the conveyance speed due to the change in the film winding diameter is suppressed. Therefore, the film conveyance speed becomes substantially constant, and the image recorded on the film can be read more accurately. Therefore, it is possible to reduce the space for arranging the conveying roller pair and the drive source of the spool shaft to reduce the size of the film conveying mechanism and to appropriately convey the film. Moreover, the manufacturing cost of a film conveyance mechanism can be reduced.

Furthermore, since the feeding state and the rewinding state are switched by the switching mechanism, complicated control is not required. Therefore, the software for controlling the driving of the conveying roller pair and the spool shaft can be simplified. In addition, the sending state and the rewinding state can be switched reliably.

  In the film transport mechanism of the present invention, the rotational force transmitting portion includes a one-way clutch that idles the spool drive shaft that rotates in the film delivery direction and the spool drive shaft that rotates in the film rewind direction. A torque limiter that prevents the applied torque from exceeding the certain value may be included. According to this structure, when sending out a film, it is possible to convey a film, suppressing damage to a film reliably. Further, when the film is rewound, the film can be transported more reliably at a constant speed.

  In the film transport mechanism of the present invention, the support member moves to the feeding position when the driving shaft rotates in the film feeding direction, and moves to the rewinding position when the driving shaft rotates in the film rewind direction. It is preferable to move. According to this configuration, since the support member moves to either the feed position or the rewind position by changing the rotation direction of the driving shaft, it is not necessary to provide another drive source for moving the support member. Therefore, the cost of the film transport mechanism can be reduced.

  A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a film scanner provided with a film transport mechanism according to the present embodiment. FIG. 2 is a perspective view of the film transport mechanism of the present embodiment. FIG. 3 is a perspective view of a rotational force transmission unit of the film transport mechanism.

  The film scanner 1 shown in FIG. 1 includes a film transport mechanism 100, an illumination optical mechanism 200, and an imaging optical mechanism 300. Further, a cartridge 70a for storing the film 80 wound around the spool shaft 70b is detachable from the film scanner 1.

  As shown in FIGS. 1 and 2, the film transport mechanism 100 includes a motor 10, a driving shaft 20 that is rotationally driven by the motor 10, and a transport roller unit 30 having four transport roller pairs 31, 32, 33, and 34. The driving belt 40 for transmitting the driving force of the driving shaft 20 to the conveying roller pairs 31 to 34, and the rotational force of the driving shaft 20 with respect to the spool shaft 70b around which the film 80 is wound in the cartridge 70a. , And a cartridge set unit 70.

  The illumination optical mechanism 200 includes a halogen lamp 220 in the lamp house 210, a dimming filter 230 that adjusts the color distribution of the light beam from the halogen lamp 220 as necessary, and a mirror tunnel 240 that also adjusts the intensity distribution. Yes.

  The imaging optical mechanism 300 includes a lens unit 310 including a zoom lens, a mirror 320 that changes the direction of irradiation light, and a photoelectric conversion unit 330 that processes a transmitted light beam that is transmitted through the film 80. Yes. Here, the photoelectric conversion unit 330 receives a light beam and performs photoelectric conversion, and includes three CCD sensors 330a, 330b, and 330c assigned to detect each color of the RBG. Here, each of the CCD sensors 330a to 330c is a line sensor in which a large number (for example, 500) of light receiving portions (photodiodes) are arranged in parallel to the main scanning direction, that is, the width direction of the film 80. Accumulation operation and charge accumulation time are controlled. A color filter that allows only the red component of the light transmitted through the film 80 to pass through the imaging surface of the red CCD sensor 330a, and similarly, a color filter that allows only the green component to pass through the imaging surface of the green CCD sensor 330b. A color filter that allows only the blue component to pass is provided on the imaging surface of the blue CCD sensor 330c, and basically, only the red component, the green component, and the blue component are photoelectrically converted. Each pixel signal output from each CCD sensor 330a to 330c is sampled and held to become an image signal in which each pixel signal is continuous, and each pixel signal is converted into a digital signal having a predetermined number of bits (for example, 12 bits). And stored as image data.

  Next, each member constituting the film transport mechanism 100 will be described in detail.

  The motor 10 rotates the driving shaft 20. The rotational force of the driving shaft 20 is transmitted to the conveying roller pairs 31 to 34 via the driving belt 40 set in the groove portion 20a provided on the outer peripheral portion thereof, and also via the rotational force transmitting portion 60. It is transmitted to the spool shaft 69. Here, the motor 10 can rotate the driving shaft 20 both in the direction in which the film 80 is unwound from the spool shaft 70b and in the direction in which the film 80 is rewound on the spool shaft 70b.

  The four conveyance roller pairs 31 to 34 of the conveyance roller unit 30 are arranged such that the conveyance roller pair 31 is closest to the cartridge setting unit 70, and from there toward the film 80 feeding direction, the conveyance roller pair 32, They are arranged in the order of 33 and 34. Accordingly, the film 80 unwound from the spool shaft 70b in the cartridge 70a is first nipped by the conveying roller pair 31, and then is sequentially nipped and conveyed by the conveying roller pairs 32-34. In addition, in FIG. 2, the conveyance path of the film 80 is drawn with the dashed-dotted line. Here, an image reading position (shown by a broken line in FIG. 2) is provided between the conveyance roller pair 32 and the conveyance roller pair 33. The transport roller pairs 31 to 34 rotate at the same speed as the rotational force of the driving shaft 20 is transmitted by the drive belt 40. Therefore, the conveyance speed of the film 80 at the image reading position is governed by the conveyance force of the conveyance roller pairs 31 to 34.

  As shown in FIG. 3, the rotational force transmission unit 60 includes a switching mechanism 61, a spool drive shaft 69 disposed in parallel to the drive shaft 20, and a feed-time rotating gear disposed coaxially with the spool drive shaft 69. 62, a revolving rotation gear 63, a one-way clutch 62a, and a torque limiter 63a. The one-way clutch 62a is fixed to the rotating gear 62 at the time of delivery, and the torque limiter 63a is fixed to the rotating gear 63 at the time of rewinding, and these rotate together. The sending rotation gear 62 and the one-way clutch 62a, and the rewinding rotation gear 63 and the torque limiter 63a are all rotatable around the spool drive shaft 69. Accordingly, as described later in detail, these can rotate together with the spool drive shaft 69 or can rotate at a rotational speed different from that of the spool drive shaft 69. Further, one end of the spool drive shaft 69 can be engaged with a spool shaft 70 b around which the film 80 is wound in the cartridge 70 a loaded in the cartridge setting unit 70.

  The switching mechanism 61 includes a large-diameter driving gear 64 and a small-diameter driving gear 65 which are two large and small gears fixed adjacent to the driving shaft 20, and two driven rotating gears 66 and 67 disposed adjacent to them. The connecting plate 68 is a substantially V-shaped member.

  A hole 68a (see FIG. 4) is formed in the acute angle portion of the connecting plate 68, and the driving shaft 20 is fitted into the hole 68a. The connecting plate 68 is pressed against the small-diameter drive gear 65 by a spring (not shown) wound around the driving shaft 20. Therefore, when the small diameter drive gear 65 rotates with the rotation of the driving shaft 20, the connecting plate 68 also rotates around the driving shaft 20 by the frictional force generated between the small diameter driving gear 65 and the connecting plate 68.

  The driven rotary gears 66 and 67 are supported in the vicinity of the projecting ends 68b and 68c (see FIG. 4) of the connecting plate 68, respectively. Here, the driven rotation gear 66 meshes with the large diameter drive gear 64, and the driven rotation gear 67 meshes with the small diameter drive gear 65. Further, the driving shaft 20 is separated from the spool shaft 70b between the driving shaft 20 and the spool driving shaft 69 rather than a line segment (drawn by a broken line in FIG. 4) connecting the driving shaft 20 and the spool driving shaft 69. A driven rotation gear 66 on the downstream side in the rotation direction and a driven rotation gear 67 on the upstream side in the rotation direction when the film 80 is rotated in the unwinding direction (clockwise in FIG. 4) are arranged.

  Accordingly, in the switching mechanism 61, when the connecting plate 68 rotates with the driving shaft 20 as a fulcrum, the driven rotation gears 66 and 67 also rotate with the driving shaft 20 as a fulcrum, and the driven rotation gear 67 and the sending rotation gear 62 and And the driven rotation gear 66 and the revolving rotation gear 63 are not engaged with each other, and the driven rotation gear 67 and the revolving rotation gear 62 are not engaged, and the driven rotation gear 66 and the revolving rotation gear 63 are engaged with each other. Can be switched.

  The one-way clutch 62a rotates integrally with the rotating gear 62 at the time of delivery. When the spool driving shaft 69 rotates faster than the rotational speed of the rotating gear 62 at the time of sending, the rotational force of the rotating gear 62 at the time of sending is not transmitted to the spool driving shaft 69 and the spool driving shaft 69 is driven. It is idle with respect to 20. In other cases, the rotating gear 62 at the time of feeding and the spool driving shaft 69 rotate together, and the rotational force of the rotating gear 62 at the time of feeding is transmitted to the spool driving shaft 69 via the one-way clutch 62a. Is done. That is, the one-way clutch 62a has a function of prohibiting the spool drive shaft 69 from rotating slowly while allowing the spool drive shaft 69 to rotate faster than the rotational speed based on the rotational force transmitted from the driving shaft 20.

  The torque limiter 63a rotates integrally with the rotating gear 63 during rewinding. Until the torque acting between the spool drive shaft 69 and the rewinding rotation gear 63 reaches the holding torque limit value of the torque limiter 63a, the rotational force of the rewinding rotation gear 63 causes the torque limiter 63a to rotate. To the spool drive shaft 69. That is, the revolving rotation gear 63 and the spool drive shaft 69 rotate together. Further, when the torque acting between the spool drive shaft 69 and the rewinding rotation gear 63 reaches the holding torque limit value, the rotational force of the rewinding rotation gear 63 is not transmitted to the spool drive shaft 69, and the winding is performed. The return rotating gear 63 and the spool drive shaft 69 rotate at different rotational speeds. That is, the torque limiter 63a rotates the spool drive shaft 69 transmitted from the drive shaft 20 until the torque acting between the spool drive shaft 69 and the rewinding rotating gear 63 reaches the holding torque limit value. Rotation slower than the rotational speed based on the force is prohibited, and when the holding torque limit value is reached, the spool drive shaft 69 can rotate slower than the rotational speed based on the rotational force transmitted from the driving shaft 20. It has a function.

  Next, the operation of the rotational force transmission unit 60 when the film 80 is sent out from the cartridge 70a will be described with reference to FIGS. FIG. 4 is a diagram for explaining the movement and meshing of the gears included in the rotational force transmission unit 60 when the film 80 is sent out from the cartridge 70a. Here, the rotation direction (clockwise or counterclockwise) of each member will be described with reference to FIG.

  First, in FIG. 3 and FIG. 4, when the driving shaft 20 rotates clockwise by transmitting the driving force of the motor 10, the large-diameter driving gear 64 and the small-diameter driving gear 65 are similarly rotated clockwise. Rotate. At this time, the connecting plate 68 rotates clockwise with the driving shaft 20 as a fulcrum. Therefore, the driven rotating gears 66 and 67 are rotated in the clockwise direction around the driving shaft 20 as a fulcrum while being integrated with the connecting plate 68 while rotating counterclockwise. As a result, the driven rotation gear 67 meshes with the rotation gear 62 at the time of delivery, and the rotational force of the small diameter drive gear 65 is transmitted to the rotation gear 62 at the time of delivery via the driven rotation gear 67. Then, the feed-out rotating gear 62 rotates in a clockwise direction together with the one-way clutch 62a. On the other hand, since the driven rotation gear 66 is not meshed with the rewinding rotation gear 63, the rotational force of the large-diameter drive gear 64 is not transmitted to the rewinding rotation gear 63.

  Here, due to the function of the one-way clutch 62 a, when the rotational speed of the spool drive shaft 69 is faster than the rotational speed of the one-way clutch 62 a, the rotational force of the rotary gear 62 during delivery is not transmitted to the spool drive shaft 69. In other cases, the rotating gear 62 at the time of delivery and the spool drive shaft 69 rotate clockwise as a unit. Accordingly, the rotational force of the driving shaft 20 is transmitted to the spool shaft 70b via the small-diameter driving gear 65, the driven rotating gear 67, the sending rotation gear 62, the one-way clutch 62a, and the spool driving shaft 69.

  Next, the operation of the rotational force transmission unit 60 when the film 80 is rewound into the cartridge 70a will be described with reference to FIGS. FIG. 5 is a diagram for explaining the movement and meshing of the gears included in the rotational force transmission unit 60 when the film 80 is rewound into the cartridge 70a. In FIG. 5, in order to make it easy to see the meshing state of each gear, a part of the connecting plate 68 and the sending rotation gear 62 are not shown. Here, the rotation direction (clockwise or counterclockwise) of each member will be described with reference to FIG.

  First, in FIGS. 3 and 5, when the driving shaft 20 rotates counterclockwise by transmitting the driving force of the motor 10, the large-diameter driving gear 64 and the small-diameter driving gear 65 also react in the same manner. Rotate clockwise. At this time, the connecting plate 68 rotates counterclockwise with the driving shaft 20 as a fulcrum. Accordingly, the driven rotary gears 66 and 67 are integrally rotated with the connecting plate 68 while rotating clockwise, and move counterclockwise around the driving shaft 20 as a fulcrum. As a result, the driven rotation gear 66 meshes with the rewinding rotation gear 63, and the rotational force of the large-diameter drive gear 64 is transmitted to the rewinding rotation gear 63 via the driven rotation gear 66. The rewinding rotating gear 63 rotates counterclockwise together with the torque limiter 63a. On the other hand, since the driven rotation gear 67 is not meshed with the rotation gear 62 at the time of delivery, the rotational force of the small diameter drive gear 65 is not transmitted to the rotation gear 62 at the time of delivery.

  Here, until the torque acting between the spool drive shaft 69 and the rewinding rotation gear 63 reaches the holding torque limit value of the torque limiter 63a by the function of the torque limiter 63a, The spool drive shaft 69 and the spool drive shaft 69 rotate counterclockwise. Accordingly, at this time, the rotational force of the driving shaft 20 is transmitted to the spool shaft 70b via the large-diameter driving gear 64, the driven rotating gear 66, the rewinding rotating gear 63, the torque limiter 63a, and the spool driving shaft 69. On the other hand, when the torque acting between the spool drive shaft 69 and the rewinding rotation gear 63 reaches the holding torque limit value of the torque limiter 63a, the rotational force of the rewinding rotation gear 63 is transmitted to the spool drive shaft 69. It will not be done.

  Further, when the film 80 is unwound from the spool shaft 70b, the conveyance speed of the film 80 at the image reading position based on the conveyance force of the conveyance roller pairs 31 to 34 driven by the transmission of the rotational force of the driving shaft 20 is as follows. The small-diameter drive gear 65, the driven rotary gear 67, and the feed are set so that the rotational force of the driving shaft 20 is faster than the feed speed of the film 80 based on the rotational force of the spool shaft 70b transmitted through the rotational force transmission unit 60. The number of teeth of the hourly rotating gear 62 is set. When the film 80 is rewound onto the spool shaft 70b, the conveyance speed of the film 80 at the image reading position based on the conveyance force of the conveyance roller pairs 31 to 34 driven by the transmission of the rotational force of the driving shaft 20 is as follows. The large-diameter driving gear 64, the driven rotating gear 66, and the rotation speed of the driving shaft 64 are set to be slower than the feeding speed of the film 80 based on the rotating force of the spool shaft 70b transmitted through the rotating force transmitting portion 60. The number of teeth of the rotating gear 63 during rewinding is set.

  Next, the operation of the film scanner 1 when press scanning and main scanning are performed will be described with reference to the drawings. FIG. 6 is a schematic diagram of the film transport mechanism 100 when the film 80 is sent out from the cartridge 70a. FIG. 7 is a schematic diagram of the film transport mechanism 100 when the film 80 is rewound into the cartridge 70a. 6 and 7, for example, the one-way clutch 62a, the torque limiter 63a, and gears that are not used when transmitting the rotational force of the driving shaft 20 to the spool drive shaft 69 are omitted. Further, in the present embodiment, press canning is performed in the process in which the film 80 is sent out from the cartridge 70a attached to the film scanner 1, while the film 80 in the process in which the sent film 80 is rewound into the cartridge 70a. Scanning is performed.

  First, when the cartridge 70 a in which the film 80 is accommodated is attached to the cartridge setting unit 70, the spool shaft 70 b around which the film 80 is wound in the cartridge 70 a is coupled to the spool drive shaft 69. Accordingly, the rotational force of the driving shaft 20 can be transmitted to the spool shaft 70b via the spool drive shaft 69.

  When the driving shaft 20 rotates in the direction of unwinding the film 80 from the spool shaft 70b, the rotational force is transmitted to the spool shaft 70b in the cartridge 70a as shown in FIG. 6, and the leading end of the film 80 is transferred to the cartridge 70a. Sent out from inside. At this time, the pair of conveyance rollers 31 to 34 of the conveyance roller unit 30 can convey the film 80 in the direction in which the film 80 is sent out from the cartridge 70a when the rotational force of the driving shaft 20 is transmitted through the drive belt 40. However, since the film 80 is not sandwiched until the leading end of the film 80 reaches the conveyance roller unit 30, the film 80 is idle. At this time, the delivery speed of the film 80 based on the rotational force of the spool shaft 70b is slower than the transport speed of the film 80 due to the transport force of the transport roller unit 30.

  Thereafter, when the leading end portion of the film 80 sent out from the cartridge 70 a reaches the transport roller portion 30, the leading end portion of the film 80 is first sandwiched between the transport roller pair 31. At this time, due to the difference between the conveyance speed of the film 80 due to the conveyance force of the conveyance roller unit 30 and the delivery speed of the film 80 based on the rotational force of the spool shaft 70b, the film 80 has a direction from the cartridge 70a toward the conveyance roller unit 30. The tension of is added. The spool shaft 70b coupled to the spool drive shaft 69 is idled with respect to the driving shaft 20 by the function of the one-way clutch 62a almost simultaneously with the leading end of the film 80 being sandwiched between the pair of conveying rollers 31. Then, the film rotates at the same speed (speed faster than the rotational speed based on the rotational force transmitted from the driving shaft 20) corresponding to the transport speed of the film 80 by the transport force of the transport roller section 30. Thereafter, the leading end portion of the film 80 is sequentially held between the transport roller pairs 32, 33, and 34. Accordingly, the film 80 in the vicinity of the image reading position is subjected to press canning while being transported at a transport speed by the transport force of the transport roller unit 30.

  When the press scanning is completed, the rotation of the driving shaft 20 is switched in the opposite direction, and the main scanning is performed in the process in which the film 80 is rewound into the cartridge 70a.

  As shown in FIG. 7, when the driving shaft 20 rotates in a direction to rewind the film 80 around the spool shaft 70b, the rotational force is transmitted to the spool shaft 70b in the cartridge 70a, and the leading end of the film 80 is moved into the cartridge 70a. Rewinded. At this time, the conveyance roller pairs 31 to 34 of the conveyance roller unit 30 can convey the film 80 in the direction in which the film 80 is rewound into the cartridge 70a when the rotational force of the driving shaft 20 is transmitted through the drive belt 40. It has become. At this time, the torque acting between the spool drive shaft 69 and the rewinding rotating gear 63 has not reached the holding torque limit value of the torque limiter 63a. The rewinding speed of the film 80 based on the rotational force of the spool shaft 70b is faster than the conveying speed. Therefore, tension is applied to the film 80 in the direction from the conveyance roller unit 30 toward the cartridge 70a.

  Here, when the torque acting between the spool drive shaft 69 and the rewinding rotating gear 63 reaches the holding torque limit value of the torque limiter 63a due to the tension applied to the film 80, the function of the torque limiter 63a causes the spool. The drive shaft 69 has the same speed as the speed corresponding to the transport speed of the film 80 by the transport force of the transport roller unit 30 (slower than the rotational speed based on the rotational force transmitted from the driving shaft 20 via the rotational force transmission unit 60). (Speed). In this way, the torque limiter 63a can absorb the speed difference between the transport speed of the film 80 by the transport roller unit 30 and the rewind speed of the film 80 by the spool drive shaft 69. As a result, the film 80 is rewound onto the spool shaft 70b while a certain tension is applied. Accordingly, the conveyance speed of the film 80 at the scanning position is maintained substantially constant, and the film 80 is properly wound around the spool shaft 70b without being slackened.

  As described above, in the film transport mechanism 100 of this embodiment, the drive of the spool drive shaft 69 and the driving shaft 20 coupled to the spool shaft 70b around which the film 80 is wound is transmitted by the single motor 10. The conveyance roller pairs 31 to 34 are driven. Therefore, the arrangement space of the motor 10 is reduced, and the film transport mechanism 100 can be downsized. Moreover, the manufacturing cost of the film transport mechanism 100 can be reduced.

  Further, since the switching mechanism 61 switches the path for transmitting the rotational force of the driving shaft 20 to the spool shaft 70b, the speed control of the feeding speed and the rewinding speed of the film 80 based on the rotational force of the spool shaft 70b is performed. The software for controlling the feeding speed and the rewinding speed of the film 80 is simplified without requiring complicated control.

  Further, when the leading end of the film 80 is sent out from the inside of the cartridge 70a, the feeding speed of the film 80 based on the rotational force of the spool shaft 70b that is rotated by the rotational force of the driving shaft 20 being transmitted is determined by the transport roller unit 30. It is controlled so as to be slower than the conveying speed of the film 80 by the conveying force. And after the front-end | tip part of the film 80 reaches | attains the conveyance roller part 30, the spool axis | shaft 70b may rotate faster than the rotational speed based on the rotational force transmitted by the drive shaft 20 by the function of the one-way clutch 62a. It becomes possible to rotate at a speed corresponding to the transport speed of the film 80 by the transport force of the transport roller section 30. Accordingly, the film 80 is smoothly conveyed without being damaged by being applied with excessive tension and without being loosened.

  Further, when the film 80 is rewound into the cartridge, the rewinding speed of the film 80 based on the rotational force of the spool shaft 70b that is rotated by the rotational force of the driving shaft 20 being transmitted is determined by the transport roller unit 30. It is controlled so as to be faster than the conveying speed of the film 80 by the conveying force. Furthermore, when the torque acting between the spool drive shaft 69 and the revolving rotary gear 63 reaches the holding torque limit value of the torque limiter 63a, the spool shaft 70b is moved by the driving shaft 20 by the function of the torque limiter 63a. It becomes possible to rotate slower than the rotational speed based on the transmitted rotational force, and it rotates at a speed corresponding to the transport speed of the film 80 by the transport force of the transport roller unit 30. Accordingly, the film 80 is rewound onto the spool shaft 70b with a constant tension, and is stored in the cartridge 70a without being loosened. Further, the rewinding speed of the film 80 based on the rotational force of the spool shaft 70b changes as the winding diameter of the film 80 changes, but this speed change can be absorbed by the function of the torque limiter 63a. Since the conveyance speed of the film 80 in the vicinity of the position is constant, scanning can be performed appropriately.

  Further, when the rotational direction of the driving shaft 20 is changed, the connecting plate 68 supporting the driven rotating gears 66 and 67 has a position where the driven rotating gear 67 meshes with the small diameter driving gear 65 and the sending rotating gear 62, and Since the driven rotary gear 66 moves to any position where it engages with the large-diameter drive gear 64 and the rewinding rotary gear 63, it is not necessary to provide a separate drive source for moving the connecting plate 68. Therefore, the manufacturing cost of the film transport mechanism 100 can be reduced.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various design changes can be made as long as they are described in the claims. Is something. For example, in the above-described embodiment, an example of the configuration of the rotational force transmission unit 60 has been described, and the configuration of the rotational force transmission unit 60 can be changed within a range where the same effect as the present embodiment can be obtained. . Therefore, the one-way clutch 62a and the torque limiter 63a included in the rotational force transmission unit 60 may be replaced with other parts having the same functions.

  Further, in the above-described embodiment, the connecting plate 68 supporting the driven rotary gears 66 and 67 is changed by the change in the rotation direction of the driving shaft 20. 62, and a position where the driven rotation gear 66 meshes with the large-diameter drive gear 64 and the rewinding rotation gear 63, but a drive source for moving the connecting plate 68 is separately provided. It may be provided.

It is a figure which shows schematic structure of the film scanner provided with the film conveyance mechanism which concerns on one embodiment of this invention. It is a perspective view of the film conveyance mechanism shown in FIG. It is a perspective view of the rotational force transmission part shown in FIG. It is a figure showing operation | movement of the switching mechanism in the case of sending out a film. It is a figure showing operation | movement of the switching mechanism in the case of rewinding a film. It is a schematic diagram of the film conveyance mechanism in the case of sending out a film. It is a schematic diagram of the film conveyance mechanism in the case of rewinding a film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Film scanner 10 Motor 20 Driving shaft 30 Conveying roller part 31, 32, 33, 34 Conveying roller pair 40 Drive belt 60 Rotational force transmission part 61 Switching mechanism 62 Rotating gear 62 at delivery 62a One-way clutch 63 Rotating gear 63 at rewinding 63a Torque limiter 69 Spool Drive Shaft 70 Cartridge Set Unit 70a Cartridge 70b Spool Shaft 80 Film 100 Film Transport Mechanism 200 Illumination Optical Mechanism 300 Imaging Optical Mechanism

Claims (3)

A spool drive shaft that supports a spool shaft on which an image-recorded film is wound;
To read an image recorded on a film, a pair of conveying rollers to rotate on the basis of the torque transmitted to unwound film from the spool shaft supported by the spool drive shaft from pinching electrolyte Tsuhara pivot shaft and ,
A feeding state in which tension is applied to the film as the pair of conveying rollers rotate in the film feeding direction, and the spool driving shaft that rotates in the film feeding direction by the tension is idled with respect to the driving shaft. And tension is applied to the film as the spool drive shaft in the film rewind direction and the spool shaft rotate, and torque applied to the spool drive shaft by the tension is applied to the film transport speed. The driving shaft and the spool driving shaft capable of selectively taking up a rewinding state in which the spool driving shaft is rotated in the film rewinding direction so as not to exceed a fixed value determined so as not to affect. A rotational force transmission unit to be coupled;
A switching mechanism for switching the state of the rotational force transmission part between the sending state and the rewinding state ,
The rotational force transmission part is
A first drive gear supported by the driving shaft;
A second drive gear supported by the driving shaft;
A rotating gear at the time of delivery supported by the spool drive shaft;
A revolving rotary gear supported by the spool drive shaft;
A first driven rotary gear capable of meshing with both the first drive gear and the delivery rotating gear in the delivery state;
A second driven rotating gear capable of meshing with both the second driving gear and the rewinding rotating gear in the rewinding state;
The switching mechanism is
The first and second driven rotating gears are supported, and the first driven rotating gear meshes with both the first drive gear and the sending rotating gear, and the second driven rotation. A support member capable of swinging between a rewind position where the gear meshes with both the second drive gear and the rewinding rotating gear;
The number of teeth of the first driving gear, the feeding rotation gear, and the first driven rotation gear is determined by the film conveyance speed based on the conveyance force of the conveyance roller pair in the delivery state. The number of teeth of the second driving gear, the rewinding rotation gear, and the second driven rotation gear is set to be in the rewinding state. A film transport mechanism, wherein the film transport speed based on the transport force of the pair of transport rollers is set to be slower than the film rewind speed based on the rotational force of the spool shaft . The rotational force transmission part is
A one-way clutch that idles the spool drive shaft rotating in the film delivery direction with respect to the driving shaft;
The film transport mechanism according to claim 1, further comprising a torque limiter configured to prevent a torque applied to the spool drive shaft rotating in the film rewind direction from exceeding the predetermined value. The support member moves to the feeding position when the driving shaft rotates in the film feeding direction, and moves to the rewinding position when the driving shaft rotates in the film rewind direction. Item 3. The film transport mechanism according to Item 1 or 2 .

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