JP2002293459A - Driving mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving mechanism capable of rewinding an image recording material with a pair of resist rollers to be rotated by the driving force transmitted through a one-way gear. SOLUTION: When normally rotating a driving motor 152 (in a direction expressed with an arrow), the driving force is generated in the one-way gear 164 to rotate a driving shaft 170 and a resist roller 71 through the one-way gear 164. When reversely rotating the driving motor 152 (in a direction opposite to the arrow), the driving force is not transmitted to the one-way gear 164, and the driving force is transmitted to a clutch gear 168 through an electromagnetic clutch 176 to reversely rotate the driving shaft 170 and the resist roller 71 through the clutch gear 168. A transmission system for transmitting the driving force to the driving shaft 170 and the resist roller 71 is changed by normally and reversely rotating the driving motor 152, and a carrying system corresponding to a purpose can be obtained by normally or reversely rotating the driving motor 152.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive mechanism using a drive gear that rotates forward and backward by a drive motor.

[0002]

2. Description of the Related Art In recent years, a printing apparatus using digital exposure, that is, an image recorded on a film is photoelectrically read, and the read image is converted into a digital signal. 2. Description of the Related Art A digital photo printer has been put into practical use that forms an image (latent image) by scanning and exposing a photosensitive material with a light beam modulated in accordance with the image data to form an image (latent image), develops the image, and outputs it as a print (photo). ing.

In a digital photo printer, tone correction and the like are performed by processing a read image (signal) to determine exposure conditions. For this reason, it is possible to freely perform various image processing such as editing of a print image such as synthesis of a plurality of images and image division by image processing, and color / density adjustment and contour emphasis. Can print out.

Further, image data of a print image can be supplied to a computer or the like, or can be stored in a recording medium such as a floppy disk. Further, according to the digital photo printer, it is possible to output a print with better image quality, which is excellent in resolution, color / density reproducibility, etc., as compared with the conventional direct exposure print.

[0005] Such a digital photo printer basically comprises an input device having a scanner (image reading device) and an image processing device, and an output device having a printing device (image recording device) and a developing device. ing.

The scanner photoelectrically reads the projection light of the image photographed on the film by an image sensor such as a CCD sensor, and sends the image data (image data signal) of the film to the image processing device. The image processing apparatus performs predetermined image processing on the image data, and sends output image data (exposure conditions) for image recording to the printing apparatus.

This printing apparatus utilizes scanning exposure of a light beam, and deflects the light beam modulated in accordance with the supplied image data in the main scanning direction. Here, the printing apparatus is provided with a sub-scanning conveyance device, which conveys the photosensitive material in a sub-scanning direction orthogonal to the main scanning direction (sub-scanning conveyance).
The photosensitive material is exposed at an exposure position provided in the sub-scanning transport device to form a latent image on the photosensitive material.

On the other hand, in a developing machine, the exposed photosensitive material is
An image photographed on a film is subjected to a predetermined development process or the like, and is a reproduced print.

By the way, a pair of conveying rollers is disposed upstream and downstream of the exposure position of the sub-scanning conveying device, and pinches and conveys the image recording material so that an image can be formed with high accuracy. On the other hand, on the upstream side of the exposure position, in order to correct the attitude of the image recording material, a registration roller is provided to adjust the width of the image recording material conveyed.

Here, in order to avoid the influence of disturbance, the conveying speed of the pair of registration rollers is made slower than the conveying speed of the conveying rollers, and the conveying rollers convey the image recording material. In addition, a one-way gear is used as a driving force transmitting means for transmitting a driving force to a shaft to which the pair of registration rollers are fixed, and only one-way rotational force is transmitted, and a linear velocity difference between the conveyance roller pair and the registration roller pair. Is greater than or equal to a certain value, the one-way gear is caused to idle, and the driving force is not transmitted to absorb the load fluctuation near the exposure position.

However, when writing is performed again after the image recording material is once stopped, the holes formed in the image recording material pass through the sensor for detecting the writing position, so that the holes cannot be detected. For this reason, it is necessary to rewind the image recording material (so-called rewind). However, since the one-way gear is used for the pair of registration rollers, the rewind cannot be performed.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described circumstances, and has as its object to provide a drive mechanism which enables a pair of registration rollers to be driven by a one-way gear to rewind an image recording material.

[0013]

According to the first aspect of the present invention, the drive gear which is normally and reversely rotated by the drive motor has the first gear.
Gear means are engaged. The first gear means is locked in the forward rotation direction, becomes free when a rotational force equal to or more than a predetermined value is applied, and becomes free in the reverse rotation direction.

The first gear means is mounted on a drive shaft provided with a roller for conveying the image recording material.
A second gear means is rotatably mounted on the drive shaft, meshes with the drive gear, becomes free with respect to the drive shaft in the normal rotation direction, and is locked to the drive shaft in the reverse rotation direction.

When an image is formed on the image recording material, the drive motor is rotated forward, and when the image recording material is rewound, the drive motor is rotated reversely. Therefore, when the drive motor is rotated forward, the first gear means is locked, so that the driving force of the drive gear is transmitted to the first gear means, and the roller rotates from the first gear means via the drive shaft, The image recording material is transported. At this time, since the second gear means is free with respect to the drive shaft, the driving force of the drive gear is not transmitted to the second gear means.

Here, when a rotational force equal to or more than a predetermined value is applied to the first gear means, the first gear means becomes free and idles around the drive shaft without transmitting the drive force from the drive gear.

For this reason, for example, when the first gear means is used for a registration roller provided in the sub-scanning conveyance device, if a linear velocity difference between the conveyance roller pair and a predetermined value or more occurs, the first gear means is used.
Since the gear means is free, the driving force is not transmitted to the registration roller, and as a result, the image recording material is conveyed only by the conveying roller pair, and no back tension is applied to the image recording material. Therefore, load fluctuation near the exposure position can be absorbed, and image unevenness and the like can be prevented.

On the other hand, when the drive motor is rotated in the reverse direction, the first gear means is free, so that the driving force of the drive gear is not transmitted to the first gear means. At this time, since the second gear means is locked to the drive shaft, the driving force of the drive gear rotates reversely from the second gear means via the drive shaft, and the image recording material can be rewound.

That is, in the forward rotation direction of the drive motor, the first
The driving force is transmitted to the gear means, and the registration roller is rotated from the first gear means via the drive shaft. However, the driving force is not transmitted to the first gear means in the reverse direction of the driving motor, but the second gear means is not transmitted. And the resist roller is rotated in reverse from the second gear means via the drive shaft.

As described above, by changing the transmission system for transmitting the driving force to the rollers via the drive shaft between the forward rotation and the reverse rotation of the drive motor, the forward rotation and the reverse rotation of the drive motor correspond to the purpose. A transport system can be obtained.

According to the second aspect of the present invention, the first gear means is a one-way gear which is unlocked when a predetermined or more rotational force is applied. When rewinding the image recording material, it is sufficient to transmit the driving force to the second gear means without transmitting the driving force to the first gear means. Therefore, a one-way gear can be used for the first gear means.

The one-way gear is unlocked when a predetermined rotational force or more is applied. Therefore, when a registration roller is used, if a linear velocity difference between the pair of transport rollers and the predetermined speed occurs, the one-way gear is rotated. Unlocked,
No driving force is transmitted to the registration roller.

For this reason, the image recording material is conveyed by the pair of conveying rollers, and no back tension is applied to the image recording material. Therefore, load fluctuation near the exposure position can be absorbed, and image unevenness and the like can be prevented.

According to the third aspect of the present invention, a gear that meshes with the drive gear is rotatably mounted on the drive shaft, and this gear is connected to the drive shaft in an ON state by an electromagnetic clutch, and is in an OFF state. To release the connection with the drive shaft.

Thus, when an image is formed on the image recording material, the electromagnetic clutch is turned off, the connection between the gear and the drive shaft is released, so that the driving force of the drive gear is not transmitted to the gear, and the image recording material is wound. When returning, the electromagnetic clutch can be turned on, the gear and the drive shaft can be connected, and the driving force of the drive gear can be transmitted to the gear.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an overall configuration of an image recording apparatus using a sub-scanning transport device to which a driving mechanism according to an embodiment of the present invention is applied will be described. (Overall Configuration of Image Recording Apparatus) An image recording apparatus 10 shown in FIGS. 1 and 2 is mainly used for an image recording apparatus of a digital photo printer, and is read and read by an image reading apparatus such as a film scanner. In accordance with the exposure condition (image recording condition) determined by the setup device according to the image obtained, the photosensitive material is scanned and exposed by light beam scanning exposure to form a latent image, and a developing process is performed. An apparatus for outputting a recorded print, which basically includes an image recording unit 12, a developing unit 14, a drying unit 16, a discharging unit 18, and an electrical unit 20 in which a control board, a power supply unit, and the like are stored.
Is configured.

Here, the image recording section 12 is provided with a printing / conveying device 22 and a light beam scanning device 24. The image recording unit 12 performs recording of image position information, image exposure (burning), back printing, and the like while pulling out the photosensitive material A wound in a roll shape on the photosensitive material magazine 27 and conveying the photosensitive material A along a predetermined path. This is a device for transporting to the developing unit 14 to be the next step, and includes a photosensitive material supply unit 26, an image position information forming unit 28 for recording image position information, an exposure unit 30, a back print unit 32, a reservoir 34, and these units. Transport means for transporting the photosensitive material A along a predetermined route that has passed.

The photosensitive material supply section 26 is a section for loading a photosensitive material magazine 27 in which a photosensitive material A wound in a roll is housed in a light-shielding housing.
2 is located on the side of the exposing means including the exposing unit 30 and the light beam scanning device 24.

In a portion adjacent to the photosensitive material magazine 27, a pair of pull-out rollers 36 for extracting the photosensitive material A from the photosensitive material magazine 27, a width guide member 40 for regulating the width direction of the photosensitive material A, and a loop of the photosensitive material A Is formed in a U-shape.

Here, the drawer roller pair 36 can be freely nipped and released by a nip release mechanism (not shown). The width (width) of the photosensitive material A is adjusted by a guide width adjustment mechanism (not shown).
The guide width is adjusted in accordance with.

On the other hand, the first loop forming section 42 forms a loop (slack) of the photosensitive material A, thereby absorbing the transportation and stop of the photosensitive material A by the image position information forming section 28 arranged downstream. Part.

On the downstream side of the first loop forming section 42,
An image position information forming section 28 is provided, and the photosensitive material A
And a punch 50 for forming a punch hole. The image position information forming section 28 is provided with position information (so-called frame information) for each print, and position information (so-called sort information) for each appropriately set unit number such as one film such as 24 or 36 sheets. ) Is formed on the photosensitive material A.

The image position information is detected by the Hall sensor 167, the photosensitive material A is exposed by the exposure unit 30 using image data corresponding to the image position, and necessary data is recorded by the back print unit 32 described later.

On the downstream side of the image position information forming section 28, an exposure section 30 is disposed with a conveying roller 56 and an endless belt 59 wound around rollers 57A to 57C interposed therebetween. The exposure unit 30 includes a second loop forming unit 58
, The sub-scanning transport section 60 and the third loop forming section 62, and the photosensitive material A loop-formed by the second loop forming section 58 is guided to the sub-scanning transport section 60.

The sub-scanning conveyance unit 60 includes the sub-scanning conveyance device 1
The sub-scanning conveyance device 150 includes guide members 90 and 92 (see FIG. 3) for guiding the photosensitive material A conveyed from the second loop forming portion 58 to an exposure position, and a registration roller pair 70. , 71, 72, and 73, and a transport roller pair 82 and 84 for transporting the photosensitive material A to the exposure position with high accuracy at the downstream side.

The photosensitive material A conveyed in the sub-scanning direction with high accuracy by the conveying roller pairs 82 and 84 is scanned and exposed in the main scanning direction by the light beam scanning device 24 so that the photosensitive material A is two-dimensionally formed. Exposed. A roller roller 86 and a roller pair 88 are disposed downstream of the conveying roller pairs 82 and 84, and the exposed photosensitive material A is guided to the third loop forming section 62.

Here, the second loop forming section 58 and the third loop forming section 62 provided on the upstream side and the downstream side of the sub-scanning transport section 60 are provided with the photosensitive material A transporting the sub-scanning transport section 60.
It is provided to suppress the behavior of.

This eliminates the adverse effects of the conveying means disposed upstream and downstream on the sub-scanning conveyance, that is, so-called back tension and pulling, thereby enabling high-precision sub-scanning conveyance of the photosensitive material A.

Further, on the downstream side of the third loop forming section 62, a back print section 32 is provided via a transport roller 98. In the back print section 32, the printing device 10
Various data such as a photographing date of the original film and a recording date on the photosensitive material A are recorded on the back surface of the photosensitive material A by 2.

Further, a first cutter 112 and a reservoir (fourth loop forming section) 34 are provided downstream of the back print section 32 via a transport roller 106. The first cutter 112 is not used in a normal operation state. For example, after the exposure operation is completed, the
The photosensitive material A is cut when, for example, all of the exposed photosensitive material A stored in the printer is discharged.

On the downstream side of the reservoir 34, the second cutter 124 and the fifth loop forming unit 1
25 are provided. The second cutter 124 is a cutter for cutting the photosensitive material A in the event of a trouble or the like. For example, when the amount of the photosensitive material A stored in the reservoir 34 becomes equal to or less than a predetermined amount, or when the developing unit 14 or the like is used. When a trouble occurs, the photosensitive material A is cut by the second cutter 124 so that the exposed photosensitive material A stored in the reservoir 34 is adversely affected, and the photosensitive material A is not required in the developing unit 14. It is possible to prevent the transport means of the printing and transporting device 22 from being damaged by being pulled.

The fifth loop forming section 125 finally absorbs the difference between the processing speed in the printing and conveying device 22 and the processing speed in the developing section 14 and the conveyance and stop of the photosensitive material A by the conveyance means 118, and develops the image. The portion 14 prevents the photosensitive material A from being unnecessarily pulled and damaged.

On the other hand, a transport roller 132 and nip rollers 134 and 135 are provided downstream of the fifth loop forming section 125, and the photosensitive material A is sent to the developing section 14. The photosensitive material A that has reached the developing unit 14 is a developing tank 136,
The paper is sent to the drying unit 16 through the fixing tank 138 and the washing tank 140, cut into a predetermined length by the cutter 148 in the discharge unit 18, printed as a finished product, and stored in the sorter 144.

Next, a description will be given of a sub-scanning conveyance device 150 to which the driving mechanism according to the embodiment of the present invention is applied. (Configuration of the sub-scanning transport device) As shown in FIG. 3 and FIG.
On the upstream side of the sub-scanning conveyance device 150, a guide member 90,
The photosensitive material A transported from the second loop forming portion 58 (see FIG. 2) is provided with guide members 90 and 92.
And guides the photosensitive material A to the downstream side of the sub-scanning conveyance device 150 while supporting the edge portion in the width direction of the photosensitive material A.

A pair of registration rollers 70, 71 and a pair of registration rollers 72, 73 are disposed between the guide member 90 and the guide member 92 (described later), and are arranged in the width direction of the photosensitive material A to be conveyed. Registration rollers 71, 73
Is slightly inclined.

As a result, the photosensitive material A is transferred to the guide member 90.
Alternatively, the photosensitive material A is guided to the downstream side of the sub-scanning and conveying device 150 while being moved toward the guide member 92 to position the photosensitive material A in the width direction.

On the downstream side of the pair of registration rollers 72 and 73, there are disposed pairs of conveyance rollers 82 and 84. A timing belt 64 is attached to one end of the pair of transport rollers 82 and 84, and the transport belt 82 and the transport roller 84 are synchronized by the timing belt 64. The transport roller pair 82 and the transport roller pair 8
4, the photosensitive material A is exposed to form an image.

Here, the conveying roller pairs 82 and 84 are capable of nip and nip release, and when forming an image on the photosensitive material A, the upstream and downstream sides of the photosensitive material A are conveyed by the conveying roller pairs 82 and 84. To form an image with high accuracy.

The photosensitive material A on which the image is formed is smoothly guided to the third loop forming section 62 by the roller pair 86 and the roller pair 88 disposed downstream of the conveying roller pair 84.

A mounting plate 165 is fixed between the pair of registration rollers 72 and 73 and the pair of conveying rollers 82, and a hall sensor 167 is provided on the mounting plate 165. The hole sensor 167 detects a writing position of an image formed on the photosensitive material A by a punch hole formed by the image position information forming unit 28 disposed downstream of the first loop forming unit 42 shown in FIG. , Light beam scanning device 2
In step 4, the image data is exposed at a predetermined timing.

On the other hand, when writing is performed again after the photosensitive material A is once stopped, a punch hole formed in the photosensitive material A passes through the hole sensor 167 to detect a writing position. A is rewound. In this case, the nip between the transport roller pairs 82 and 84 is released.

Next, a driving mechanism according to the embodiment of the present invention will be described.

First, the configuration of the driving mechanism according to the embodiment of the present invention will be described.

As shown in FIG. 5, the sub-scanning conveyance device 150
Are provided with registration rollers 71 and 73. The registration rollers 71 and 73 are rotatable by a driving force transmitted from a driving motor 152 by a driving mechanism 151.

A pinion 154 is connected to the drive motor 152, and the driving force of the drive motor 152 is
The pinion 154 is rotatable forward and reverse. This pinion 154 has a large gear 1 of gear 156.
58 are in mesh with each other and can rotate forward and backward. The small gear 160 rotates forward / reverse via the large gear 158.

The small gear 160 meshes with the drive gear 162, so that the drive gear 162 can rotate forward and reverse. The driving gear 162 includes a one-way gear 1
The gears 64, 166 and the clutch gear 168 are engaged with each other, and can rotate forward and reverse.

Here, the one-way gear 164 and the clutch gear 168 are rotatably mounted on the drive shaft 170, and the one-way gear 166 is
72 is rotatably mounted.

The one-way gears 164 and 166 are
With respect to the rotation in the direction of the arrow (forward rotation), the drive shaft 17
0 and 172, respectively.
In the rotation in the direction of the arrow, the one-way gears 164 and 166 and the drive shafts 170 and 172 rotate integrally.

On the other hand, in the rotation in the direction opposite to the arrow direction (reverse rotation), the one-way gears 164 and 166 are unlocked from the drive shafts 170 and 172, respectively, and the one-way gears 164 and 166 are unlocked from the drive shafts 170 and 17 respectively.
Spin idle for 2.

Further, when the one-way gears 164 and 166 are locked to the drive shafts 170 and 172 and a rotational force exceeding a predetermined value is applied, the one-way gears 164 and 166 are unlocked and idle with respect to the drive shafts 170 and 172. I have.

On the other hand, an electromagnetic clutch 176 is attached to the clutch gear 168.
Is rotatably attached to the drive shaft 170.
When the electromagnetic clutch 176 is ON, the electromagnetic clutch 1
Reference numeral 76 designates connection with the drive shaft 170. When the electromagnetic clutch 176 is in the OFF state, the connection with the drive shaft 170 is released, and the electromagnetic clutch 176 idles with respect to the drive shaft 170 together with the clutch gear 168. It has become.

Incidentally, registration rollers 71 and 73 are fixed to the drive shafts 170 and 172, respectively, and are rotatable integrally with the drive shafts 170 and 172. The registration rollers 71 and 73 are in contact with registration rollers 70 and 72, respectively. The registration rollers 70 and 72 are provided with springs 174 (see FIG. 3).
73 side.

Next, the operation of the driving mechanism 151 according to the embodiment of the present invention will be described.

When an image is formed on the photosensitive material A, the drive motor 152 rotates in the direction of the arrow (forward rotation). When the drive motor 152 rotates in the direction of the arrow, the pinion 154 is rotated.
, The large gear 158 rotates in the direction of the arrow, whereby the small gear 160 rotates in the direction of the arrow to drive the gear 162.
The driving force from the driving motor 152 is transmitted.

The rotation of the driving gear 162 causes the clutch gear 168 and the one-way gears 164 and 166 to rotate in the direction of the arrow. At this time, the one-way gears 164, 1
66 is locked to the drive shafts 170, 172, and is connected to the drive shafts 17 via one-way gears 164, 166.
0, 172 rotate.

As a result, the registration rollers 71 and 73 rotate in the direction of the arrow, and the photosensitive material A passing between the registration rollers 71 and 73 and the registration rollers 70 and 72 can be conveyed. Here, the registration rollers 70 and 72
Of the photosensitive material A by the pressing force of the spring 174 provided on the photosensitive material A
Are nipped and conveyed.

It is preferable that the photosensitive material A is conveyed by synchronizing the registration rollers 71 and 73 with the pair of conveyance rollers 82 and 84. However, the registration rollers 71 and 73 and the pair of conveyance rollers 82 and 84 are completely synchronized. It is difficult to do that.

Therefore, the linear speed of the registration rollers 71, 73 is made slower than the linear speed of the pair of transport rollers 82, 84 without synchronizing the registration rollers 71, 73 with the pair of transport rollers 82, 84 (here, the register rollers 71, 73). , About -5% of the linear velocity of the pair of conveying rollers 82 and 84).
2, 84.

On the other hand, when the one-way gears 164 and 166 are locked to the drive shafts 170 and 172 and a rotational force exceeding a predetermined value is applied, the one-way gears 164 and 166 are unlocked and idle around the drive shafts 170 and 172. I have.

Therefore, the pair of registration rollers 70 and 71, the pair of registration rollers 72 and 73, and the pair of conveyance rollers 82 and 8
When a linear velocity difference equal to or greater than a predetermined value is generated between the one-way gears 164 and 184 (about -5% or more of the linear velocity of the conveying roller pairs 82 and 84), the one-way gears 164 and 166 idle with the drive shafts 170 and 172.

As a result, the driving force from the drive gear 162 is not transmitted to the drive shafts 170 and 172, and the photosensitive material A is transported only by the transport roller pairs 82 and 84. Is not applied.

As described above, when a linear velocity difference of a predetermined value or more occurs between the pair of conveying rollers 82 and 84, the one-way gear 16
By spinning 4, 166, load fluctuations near the exposure position can be absorbed, and image unevenness and the like can be prevented.

On the other hand, when an image is formed on the photosensitive material A, the electromagnetic clutch 176 is in the OFF state.
The connection with the drive shaft 170 has been released. As a result, the electromagnetic clutch 176 and the clutch gear 168 run idle with respect to the drive shaft 170, so that the drive gear 16
No driving force is transmitted from 2 to clutch gear 168.

When rewinding the photosensitive material A, the nip of the conveying roller pair 82 and 84 is released, and the drive motor 152 is rotated in the direction opposite to the arrow (reverse rotation). Drive motor 15
2 reversely rotates, the large gear 15 through the pinion 154.
8 rotates in reverse, whereby the small gear 160 rotates in reverse and the driving force from the drive motor 152 is transmitted to the drive gear 162.

The rotation of the driving gear 162 causes the clutch gear 168 and the one-way gears 164 and 166 to rotate in the reverse direction. For this reason, the one-way gears 164 and 166 are unlocked from the drive shafts 170 and 172,
It idles with respect to the drive shafts 170, 172.

Therefore, the driving force from the driving motor 152 is transmitted to the one-way gears 164, 164 through the driving gear 162.
66 cannot be transmitted to the drive shafts 170, 172.

On the other hand, when rewinding the photosensitive material A, the electromagnetic clutch 176 is in the ON state, and the electromagnetic clutch 176 is connected to the drive shaft 170. For this reason,
The clutch gear 168 is integrated with the drive shaft 170 via the electromagnetic clutch 176, and the driving force from the drive gear 162 is applied to the drive shaft 170 via the clutch gear 168.
Is transmitted to

Thus, the registration roller 71 fixed to the drive shaft 170 can be rotated in the reverse direction, and the photosensitive material A can be rewound.

That is, in the forward rotation of the drive motor 152 (in the direction of the arrow), the driving force is transmitted to the one-way gear 164 and the drive shaft 170 is transmitted via the one-way gear 164.
And the registration roller 71 is rotated.
In the reverse rotation of 52 (in the direction opposite to the arrow), the driving force is transmitted to the clutch gear 168 via the electromagnetic clutch 176 without transmitting the driving force to the one-way gear 164, and the drive shaft 170 is transmitted via the clutch gear 168. Then, the registration roller 71 is rotated in the reverse direction.

As described above, by changing the transmission system for transmitting the driving force to the drive shaft 170 and the registration roller 71 between the forward rotation and the reverse rotation of the drive motor 152, the drive motor
In each of the forward rotation and the reverse rotation of No. 2, it is possible to obtain a transport system suitable for the purpose, and it is possible to use the one-way gear 164 as the first gear means.

As a result, the registration roller pair 70, 71
And a pair of registration rollers 72, 73 and a pair of conveyance rollers 82,
When a difference in linear velocity between the resist rollers 84 and 84 exceeds a predetermined value, the driving force is not transmitted to the registration rollers 71 and 73, thereby absorbing a load fluctuation near the exposure position and preventing image unevenness and the like. .

In this case, the driving mechanism is used in the sub-scanning conveyance device 150. However, the driving mechanism is not limited to this as long as the device changes the conveyance direction of the photosensitive material A. Also,
Although the one-way gear 164 was used as the first gear means,
The gears are not limited to one-way gears, since they are locked in the forward rotation direction and become free when a predetermined or more rotational force is applied, and become free in the reverse rotation direction.

Further, here, the electromagnetic clutch 176 is used, and the clutch gear 16 is connected via the electromagnetic clutch 176.
8 is fixed to the drive shaft 170, but the drive motor 1
52, the driving force can be transmitted to the one-way gear 164. When the driving motor 152 rotates in the reverse direction, the clutch gear 16
However, the present invention is not limited to this as long as the driving force can be transmitted to the motor 8.

For example, using a one-way gear for the gear,
When the drive motor 152 rotates forward, the drive shaft 170 may idle, and when the drive motor 152 rotates reversely, the drive shaft 170 may be locked so that the driving force is transmitted only when the drive motor 152 rotates reversely.

[0085]

According to the present invention, the above configuration is provided.
In the invention described in (1), the driving force is transmitted to the first gear means in the normal rotation direction of the drive motor, and the registration roller is rotated from the first gear means via the drive shaft. The driving force is transmitted to the second gear means without transmitting the driving force to the gear means, and the resist roller is rotated reversely from the second gear means via the drive shaft. Thus, by changing the transmission system that transmits the driving force to the roller via the drive shaft between the forward rotation and the reverse rotation of the drive motor,
In each of the forward rotation and the reverse rotation of the drive motor, a transport system suitable for the purpose can be obtained.

According to the second aspect of the present invention, the image recording material is transported by the transport roller pair, and the image recording material is not back-tensioned. Therefore, load fluctuation near the exposure position can be absorbed, and image unevenness and the like can be prevented.

According to the third aspect of the invention, when an image is formed on an image recording material, the electromagnetic clutch is turned off.
Disengage the connection between the gear and the drive shaft so that the driving force of the drive gear is not transmitted to the gear. When rewinding the image recording material, turn on the electromagnetic clutch and connect the gear and the drive shaft to drive the drive gear. Force can be transmitted to the gear.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an image recording apparatus provided with a printing / conveying apparatus including a sub-scanning / conveying apparatus to which a driving mechanism according to the embodiment is applied.

FIG. 2 is a schematic side view of a printing and conveying device including a sub-scanning and conveying device to which the driving mechanism according to the embodiment is applied.

FIG. 3 is a perspective view of a sub-scanning conveyance device to which the driving mechanism according to the embodiment is applied.

FIG. 4 is a schematic plan view of a sub-scanning conveyance device to which the driving mechanism according to the embodiment is applied.

FIG. 5 is a perspective view showing a driving mechanism according to the embodiment.

[Explanation of symbols]

 151 drive mechanism 162 drive gear 164 one-way gear (first gear means) 168 clutch gear (second gear means) 170 drive shaft 176 electromagnetic clutch (second gear means)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H106 AB46 AB69 BA11 3F103 AA02 BA04 BA12 3J009 DA20 EA04 EA11 EA21 EA32 ED06 ED07 FA17 FA18 3J062 AA36 AB01 AC04 BA14 BA19 BA29 CF02

Claims (3)

[Claims] 1. A drive gear that rotates forward and backward by a drive motor, and a first gear unit that meshes with the drive gear, is locked in a forward rotation direction, becomes free when a predetermined rotational force or more is applied, and becomes free in a reverse rotation direction, A drive shaft provided with the first gear means and provided with a roller for conveying the image recording material; rotatably mounted on the drive shaft, meshing with the drive gear, and free with respect to the drive shaft in the normal rotation direction; And a second gear means locked to the drive shaft in the reverse direction. 2. The drive mechanism according to claim 1, wherein the first gear unit is a one-way gear that is unlocked when a predetermined rotational force or more is applied. 3. The second gear means is rotatably mounted on the drive shaft, and connects a gear meshing with the drive gear to the gear and the drive shaft in an ON state.
The drive mechanism according to claim 1, further comprising: an electromagnetic clutch that releases a connection between the gear and the drive shaft in an OFF state.