JP3141666B2 - Image information processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image information processing apparatus such as an image recording apparatus or an image reading apparatus having a processing unit for recording or reading a sheet-shaped recording medium to be conveyed.

[0002]

2. Description of the Related Art In an image recording apparatus requiring a high-quality image such as a medical image, the sub-scanning system is required to have a stable conveyance performance. For this reason, in this type of conventional image recording apparatus, a method of nipping and transporting a medium (recording medium) such as a photosensitive film between one sub-scanning drum and two nip rollers has been adopted. . Since the transport of the medium is performed by one sub-scanning drum, stable transport of the medium can be realized.

However, since the sub-scanning drum for driving the conveyance of the medium has a relatively large diameter (for example, φ70 mm), the size of the image recording apparatus is inevitably increased.

In order to reduce the size of an image recording apparatus,
Conventionally, there has been proposed a method in which a roller diameter is reduced, and a medium is conveyed while being sandwiched between two pairs of rollers.

[0005]

However, when the medium is transported by two pairs of rollers, the force for restraining the media by each roller pair varies, the speed at which the medium is transported varies, and the sub-scanning system does not work. The stable conveyance of the medium is hindered by the resistance to the medium on the upstream side or the downstream side, and it is difficult to record a high-quality image.

Therefore, according to the present invention, the recording medium can be miniaturized by nipping and transporting the recording medium between two pairs of rollers, and furthermore, a stable transport performance can be realized to record or read a high-quality image. It is an object to provide an image information processing device.

[0007]

According to the present invention, there is provided an image information processing apparatus having a processing unit for performing recording or reading on a conveyed sheet-shaped recording medium. A first driving roller pair having a driving force is provided on the upstream side along the conveyance direction of the recording medium, and a second driving roller pair having a driving force on the downstream side along the conveyance direction of the recording medium from the processing unit. A driving roller pair is provided, and the first driving roller pair and the second driving roller pair are arranged such that the recording medium conveying force of the first driving roller pair> the recording medium conveying force of the second driving roller pair, and the first driving roller pair And the first driving roller pair is driven in such a manner that the recording medium conveyance speed by the second driving roller pair <the recording medium conveyance speed by the second driving roller pair .
Connected to an attenuating member that attenuates loads below the specified load value.
An image information processing apparatus characterized by the.

[0008]

[0009]

The recording medium is transported by two pairs of driving rollers having a relatively small diameter without using a relatively large-diameter drum, so that a driving system for transporting the recording medium in the processing section becomes small, and as a result, The image information processing apparatus becomes smaller.

[0010] Further, the first drive roller pair and the second drive roller pair may be set such that the recording medium conveyance force by the first drive roller pair> the recording medium conveyance force by the second drive roller pair, and the recording by the first drive roller pair. By driving such that the medium conveyance speed <the recording medium conveyance speed by the second drive roller pair,
The first drive roller pair is driven to feed the recording medium without slipping, and the second drive roller pair is driven to slide and feed the recording medium. This also makes it less likely to be affected by the drag (disturbance) on the recording medium upstream or downstream of the processing unit. As a result, the conveyance stability of the recording medium in the processing section is improved, so that a high-quality image is recorded or read.

Further, an attenuation member is connected to the first driving roller pair.
As a result , a load that is equal to or less than a predetermined load value applied from a motor or the like is attenuated, and the speed fluctuation of the first drive roller pair is suppressed. Further, the fluctuation of the recording medium conveyance speed caused by the speed difference between the recording medium conveyance speed by the first drive roller pair and the recording medium conveyance speed by the second drive roller pair can be suppressed. As a result, the conveyance stability of the recording medium in the processing unit is further improved, so that a higher quality image can be recorded or read.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing the overall configuration of a laser printer according to an embodiment of the image information processing apparatus of the present invention.
FIG. 3 is a top view showing a positional relationship between the cartridge and the sub-scanning unit shown in FIG.

In the laser printer 10, a cartridge 12, a film feeding unit 13, an image forming unit 14, and a heat developing unit 15 are mainly arranged as shown in an apparatus main body 11 in which the inside is formed in a dark box state. Has been established. Recording media handled by this laser printer 10
Denotes a photosensitive film 16 for handling medical images and color images. FIG. 1 shows a state in which the cartridge 12 containing the photosensitive film 16 is mounted in the apparatus main body 11. In addition, the laser printer 10 of the present embodiment
In the image forming unit 14, the transport direction of the film 16 is a vertical direction from bottom to top, and the sub-scan is performed on the film 16 transported in the vertical direction so that a predetermined image is formed. It has become. The film 16 fed by the film feeding unit 13 is transported along a substantially U-shaped transport path from the upstream side to the downstream side of the image forming unit 14.

The transport path in this area includes a lower horizontal transport area 17L extending substantially in the horizontal direction, and a lower round transport area extending in an arc shape from the end of the lower horizontal transport area 17L toward the image forming section 14. 18L, a lower vertical transport area 19L extending vertically upward from an end of the lower round transport area 18L, and an upper vertical transport area 19U extending vertically upward from the downstream side of the image forming unit 14.
There is an upper round transfer area 18U extending in an arc shape from the end of the upper vertical transfer area 19U toward the thermal developing section 15, and an upper horizontal transfer area 17U extending substantially horizontally from the end of the upper round transfer area 18U. are doing. In the following description, the lower horizontal transfer area 17
L, the lower round transfer area 18L and the lower vertical transfer area 19L are collectively referred to as a lower transfer area 20, and the upper vertical transfer area 19U, the upper round transfer area 18U, and the upper horizontal transfer area 17U are collectively referred to as upper transfer. Also referred to as area 21.

In the apparatus main body 11, a guide plate 22 forming a lower horizontal transfer area 17L, a guide plate 23 forming a lower round transfer area 18L and a lower vertical transfer area 19L, and an upper vertical transfer area 19U are formed. Guide plate 2
4. Guide plate 2 forming upper round transfer area 18U
5. Guide plate 26 forming upper horizontal transport area 17U
Are provided respectively.

The cartridge 12 is exchangeably mounted in the lower portion of the apparatus main body 11 and houses unexposed films 16 in a stacked state. A light-shielding slide door 28 is attached to an opening 27 on the upper surface. Have been. Cartridge 1
2 is normally shielded from light in order to protect the photosensitive film 16, but is installed in the apparatus main body 11, and when the light shielding inside the apparatus main body 11 is secured, the slide door 28 is Is moved, and the opening / closing opening 27 is automatically opened.

The film feeding section 13 includes a cartridge 1
There is provided a vacuum type film feeding device 30 for feeding the photosensitive films 16 stored in the sheet 2 one by one. This feeding device 30 is configured such that a suction disk holding unit 32 having a vacuum suction disk 31 is attached to a tip of a paper feeding arm 33. When a paper feed command comes,
The vacuum suction disk 31 is in contact with the uppermost film 16 while maintaining a horizontal posture, and is vacuum-sucked.
Is fed between the first pair of transport rollers 34 that are arranged so as to be able to approach and move away from the entrance of the film transport path when the paper feed arm 33 rotates. Then, when the film 16 is restrained by the first transport roller pair 34, the suction state is released, and the suction disk holding unit 32 returns to the home position.

The first transport roller pair 34 includes the drive roller 3
4a and a driven roller 34b.
4b moves so as to be able to contact and separate from the drive roller 34a, and in the released state, the leading end of one film 16 picked up by the feeding device 30 is inserted. The sheet is fed to the second transport roller pair 36 along the arc-shaped guide plate 35. The second transport roller pair 36 includes an upper roller 36a and a lower roller 36b.
6a by the transport sensor SW1 provided upstream of the film 1a.
6 is detected to detect that the film 16 has reliably entered the lower horizontal transport area 17L.

In the lower horizontal transport area 17L, the film 16 is transported while its width is regulated by a width regulating means such as a skew correction roller pair (not shown). The lower horizontal transfer area 17L has an upper roller 37 serving as a driving roller.
a, and a third transport roller pair 37 composed of a lower roller 37b which is a driven roller. The lower roller 37b moves so as to be able to contact and separate from the upper roller 37a. In the released state, the leading end of the film 16 sent from the second conveying roller pair 36 is inserted. The film 16 is fed along the guide plate 23 toward the image forming unit 14. When the film 16 reaches the main drive roller pair 42 of the sub-scanning unit 41 described later in the image forming unit 14, the third transport roller pair 37 is used to reduce the load of film transport on the main drive roller pair 42. Film 16
Is released.

The image forming section 14 has an optical unit 40 and a sub-scanning unit 41. The optical unit 40 is disposed on the left side of the sub-scanning unit 41 in the drawing.
The lower horizontal transfer area 17L is formed below the optical unit 40, and the upper horizontal transfer area 17L is formed above the optical unit 40.
U is formed.

The optical unit 40 incorporates a laser light source, an optical modulator, a polygon mirror, a folding mirror, and the like, and deflects a laser beam L modulated according to an image signal in the main scanning direction by using rotation of the polygon mirror. Then, the photosensitive surface of the film 16 at the recording position is optically scanned. During the transport of the film 16, the laser beam L is not irradiated onto the film 16 by a shutter or the like.

The sub-scanning unit 41 has an upstream main driving roller pair 42 (corresponding to a first driving roller pair) and a downstream sub driving roller pair 43 (corresponding to a second driving roller pair).
And the rollers 42 and 43 are covered with an elastic member. The film 16 is nipped and conveyed by the main drive roller pair 42 and the sub drive roller pair 43. At this time, the image is formed by the laser beam L that is main-scanned between the optical unit 40 and the two roller pairs 42 and 43. Exposed. The sub-scanning unit 41 will be described later in detail with reference to FIGS.

The upper vertical transport area 21 includes a driving roller 4
A fourth transport roller pair 44 composed of 4a and a driven roller 44b, a fifth transport roller pair 45 composed of a drive roller 45a and a driven roller 45b, a sixth transport roller pair 46, and the like are provided. I have.

Film 16 exposed in image forming section 14
Is transported toward a heat roller 47 provided in the heat developing unit 15 by driving the fourth to sixth transport roller pairs 44, 45, 46. The exposed film 16 is successively thermally developed by the heat roller 47, and a discharge tray 49 provided on the upper surface of the laser printer 10 by a discharge roller pair 48.
Discharged upward. A receiving cartridge is arranged at the position of the heat roller 47, and the exposed film 16 accommodated in the receiving cartridge is taken out of the laser printer 10 together with the receiving cartridge with the receiving cartridge in a light-shielding state. May be performed.

A controller (not shown) is provided in the apparatus main body 11 so as to perform overall control of each unit in the apparatus main body 11. Meanwhile, laser printer 1
To 0, a computer (not shown) is connected, and image information to be recorded is input from the computer to the controller of the laser printer 10 one image at a time.

FIG. 3 is a side view showing a main part of the sub-scanning unit, FIG. 4 is a top view thereof, and FIG. 5 is a schematic perspective view showing a power transmission relationship of a drive system in the sub-scanning unit.

As shown in FIG. 3, in the sub-scanning unit 41, the transport direction of the film 16 is a vertical direction from bottom to top, and a main drive roller pair 42 is provided on the upstream side in the film transport direction. A pair of driven rollers 43 is provided on the side. The main drive roller pair 42 and the sub drive roller pair 43 are arranged with a gap having a predetermined dimension therebetween, and an exposure unit 50 (corresponding to a processing unit) is formed. In the exposure section 50, the film 16 is irradiated with the laser beam L from the optical unit 40, and image information is recorded.

The main drive roller pair 42 includes a main drive roller 42
a and the main drive roller 4a pressed against the main drive roller 42a.
2a, and an opposing roller 42b that rotates with the rotation drive of 2a. Similarly, the sub-drive roller pair 43 is composed of a sub-drive roller 43a and an opposing roller 43b which comes into pressure contact with the sub-drive roller 43a and rotates with the rotation of the sub-drive roller 43a. In the following description, the main drive roller pair 42 is also referred to as a main drive unit, and the sub drive roller pair 43 is also referred to as a sub drive unit.

Each of the opposed rollers 42b and 43b is rotatably mounted on a support plate 52 which is rotatably mounted on the apparatus main body 11 about a support shaft 51. Each support plate 52
Is provided with an arm portion 53, and a tension spring 54 is stretched between the two arm portions 53. Due to the elastic force of the tension spring 54, the support plate 52
As a result, the opposing rollers 42b and 43b are pressed against the main drive roller 42a and the sub drive roller 43a.

On the upstream side of the main drive roller 42a, a leading end detection sensor SW2 is provided close to the main drive roller 42a. The leading edge detection sensor SW2 detects that the leading edge of the film has passed from the back side of the film exposure surface.

The detection method of the leading end detection sensor SW2 and the conveyance sensor SW1 provided upstream of the second conveyance roller pair 36 is not particularly limited. However, the recording medium used in the printer 10 of this embodiment is the photosensitive film 1
In the case of using a contact type sensor provided with a detection member, the detection member needs to be retracted to the OFF position where the detection member does not contact the film 16 as soon as the film 16 is detected, particularly, the leading end of the film. . If the detecting member is not retracted, it appears as a vertical stripe on the film 16 and damages the image. Also,
The tip detection sensor SW2 and the conveyance sensor SW1 are composed of a photo sensor, and the photosensitive film 1 is
In the case where the film 6 is directly detected, it is necessary to turn off the light emission of the photo sensor immediately after detecting the film 16, especially the leading end of the film, in order to prevent exposure to the film 16. Further, according to the photosensor, since the film 16 is directly detected without the intervention of the detection member, there is an advantage that cost can be reduced, space can be saved, and a detection error is small.

As shown in FIGS. 4 and 5, the driving system 60 of the sub-operation unit 41 has a sub-scanning motor M composed of a pulse motor, and a motor pulley 61 is connected to the output shaft of the sub-scanning motor M. Have been. This motor pulley 6
A first belt 63 that transmits the rotation of the sub-scanning motor M to the main drive roller 42a is stretched between the first drive roller 42a and the main drive roller 42a. The drive system 60 includes a first intermediate pulley 6 at both ends.
An intermediate shaft 66 connecting the fourth intermediate pulley 4 and the second intermediate pulley 65 is arranged, and a second belt 67 is stretched between the motor pulley 61 and the first intermediate pulley 64. Further, a third belt 69 that transmits the rotation of the sub-scanning motor M to the sub-drive roller 43a is hung between the second intermediate pulley 65 and the sub-drive roller pulley 68 to which the sub-drive roller 43a is connected. Has been passed.

According to such a drive system 60, the power is directly transmitted from the motor M without transmitting the power from the sub-drive unit 43 on the main drive unit 42 side, and the power is also transmitted from the motor M on the sub-drive unit 43 side. Power is transmitted directly from the motor M without power being transmitted from the main drive unit 42 side. Therefore, the driving stability of the main driving roller pair 42 as the main driving unit is improved.

Further, the first intermediate pulley 64 is provided with a torque limiter 70 for regulating the conveying force of the sub-drive unit 43. The power of the sub-scanning motor M is supplied to the first intermediate pulley 64 via the torque limiter 70. 43a.

The configuration of the main and sub drive rollers 42 and 43, the necessity of the torque limiter 70, the reason for the existence of the intermediate shaft 66, the speed ratio between the main drive roller 42a and the sub drive roller 43a, and the tip detection sensor SW2 will be described below. explain.

Structure of Driving Roller In the printer 10 of this embodiment, the driving system 60 of the sub-scanning unit 41 is constituted by two pairs of rollers (a main driving roller pair 42 and a sub-driving roller pair 43). These rollers 4
Since 2a, 42b, 43a, and 43b have smaller diameters than the conventional drum, space saving of the sub-scanning unit 41 and further downsizing of the printer 10 can be achieved, and cost can be reduced.

With the above configuration, the function of "performing stable conveyance" required for the sub-scanning unit 41 must be achieved. The internal disturbance exerted on the driving system 60 of the sub-scanning unit 41 may be vibration from the sub-scanning motor M, transmission error of the driving transmission system (belts 63, 67, 69), and the like. The influence of the resistance and the resistance of the feeding to the developing unit 15 is greater.

Conventionally, in order to reduce the influence of the disturbance, when the film 16 is transported by the sub-scanning drive roller, the roller pair of the transport unit and the developing unit 15 is
By taking evacuation against, consideration was given to avoid resistance.

However, although the influence is reduced by such consideration, the resistance is not necessarily zero due to the shape of the film transport path, the stiffness of the film 16, and the like.

Now, as shown in FIG. 6A, load resistance in the transport section: a resistance to sending to the developing section: b transport force in the main drive section: F transport speed in the main drive section: v Assuming that the conveying force at the driving unit: F ', and the conveying speed at the sub-driving unit: v', the main driving unit 42
Then, since the film 16 must not slip, F> F ′ and F> a, and in the area of the exposure unit 50, the film 16 must not be slackened, so that F ′> b and v ≦ v ′ are satisfied. It can be understood that stable transport can be performed, that is, a force relationship that is not affected by disturbance.

As a comparative example, consider the case of a drive system in which the main drive unit 42 is disposed downstream and the drive unit 43 is disposed upstream along the film transport direction. F ′> a In order to transport the film 16 from the sub-drive unit 43 to the main drive unit 42, the film 16 must not be slackened in the area of the exposure unit 50, and v ≧ v ′ F > A + b + f (f is the load resistance in the sub-drive unit coming from v ≧ v ′).

Comparing the F value between the configuration of the present embodiment and the configuration of the comparative example, it is understood that the configuration of the present embodiment is more advantageous in setting the design value.

Necessity of Torque Limiter The basic requirements of the drive system 60 of the sub-scanning unit 41 are as follows: film transport force: main drive section 42> subordinate drive section 43 film transport speed: main drive section 42 Side <the sub-drive unit 43 side, and the main drive roller pair 42 and the sub-drive roller pair 43 are driven in the above-described relationship, so that the main drive roller pair 4
In 2, the film 16 is driven to be fed without slipping, and in the driven roller pair 43, the film 16 is driven to be slipped.

As described above, a slip occurs between the slave driving roller 43a and the film 16, and such a slip occurs when the photosensitive film 16 having an emulsion surface is conveyed. This causes scratches on the emulsion surface. Main drive roller pair 42 and slave drive roller pair 43
And the driven roller 43 when driving in the above relationship.
In order to prevent the slip between the a and the film 16, the torque limiter 70 is connected to the sub-scanning motor M and the sub-drive roller 43.
It is conceivable to put it in the transmission system between a.

Therefore, in this embodiment handling the photosensitive film 16, a torque limiter 70 is attached to the intermediate shaft 66 via the first intermediate pulley 64, as shown in FIG. The torque value of the torque limiter 70 is set to about 200 g · cm based on the condition that “the film transporting force is greater than the main driving unit 42> the sub driving unit 43 side”. At this time,
The torque value on the main drive section 42 side is about 1 kg · cm.

By interposing the torque limiter 70, the film 16 and the roller 4
The rollers 42a, 42b take into account the frictional force between the rollers 42a, 42b.
Although it is necessary to select the material b, the frictional force between the film 16 and the rollers 43a and 43b does not need to be noticed so much on the side of the driven section 43. That is, it is sufficient that the film 16 and the rollers 43a and 43b do not slip.
What is necessary is just to select the material which can obtain the binding force of 00 g · cm or more. Therefore, a roller made of the same material as that of the main drive unit 42 may be used.

The driven roller 43a and the film 16
When transporting a recording medium having a material that does not cause any trouble even if a slip occurs between the driving system 6 and the driving system 6 of the sub-scanning unit 41,
It is not necessary to attach the torque limiter 70 to zero.

[0048] In use reason this embodiment of the intermediate shaft, using an intermediate shaft 66 for the following two reasons. Since the torque limiter 70 is a component that is long in the axial direction,
If the torque limiter 70 is attached to the driven roller 43a via a pulley, the length in the axial direction increases, and the size of the printer 10 increases in the axial direction. Also,
The axial length of the driven roller 43a is increased, and the cost of the roller 43a, which is a functional component, is increased. On the other hand, by attaching the torque limiter 70 to the intermediate shaft 66, which is merely a power transmission shaft, as in the present embodiment, the torque limiter 70 can be arranged in parallel with the sub-scanning motor M. Space saving can be achieved, and there is no need to attach the torque limiter 70 to the driven roller 43a, and there is no increase in cost.

This is because it is necessary to prevent the transmission error of the drive transmission system, which is one of the disturbances affecting the drive system 60 of the sub-scanning unit 41, from being added to the main drive roller 42a. Therefore, the power transmission to the sub-drive roller 43a is not performed by the main drive roller side pulley 62 but by the motor pulley 6
From 1. Further, the intermediate shaft 66 is required from the viewpoint of the arrangement of the main driving roller 42a and the sub driving roller 43a and the diameter of the pulley attached to the rollers.

The speed ratio between the main drive roller and the slave drive roller
Although the transport speed is set so that the main drive unit-side transport speed v <the slave drive unit-side transport speed v ', the speed ratio is set to 1: 1.1 or less. The reason for setting the speed ratio in this manner is as follows. The film 16 having passed through the main drive roller 42a follows the transport speed of the slave drive roller 43a. Printer 10 of the type that forms an image on the entire surface of the film
In this case, the unevenness of the image density due to the difference in the transport speed is a serious problem, but if it is 1.1 or less, the effect can be suppressed to a small extent.

The front end detecting sensor tip detection sensor SW2 for detects the end of the film is intended to know the image formation timing, in the illustrated embodiment, it is disposed on the upstream side of the main drive roller pair 42. The driving system 60 of the sub-scanning unit 41 in the printer 10
Is constituted by two pairs of rollers 42 and 43, the leading end detection sensor SW2 can be arranged between the pair of rollers 42 and 43. Then, the tip detection sensor SW2
Is arranged slightly upstream of the exposure unit 50 between the pair of rollers 42 and 43, the image forming operation can be started immediately upon detection of the leading end of the film, so that there is no need to time the timing. Therefore, the tip detection sensor SW
According to the sub-scanning unit 41 in which the roller 2 is disposed between the pair of rollers 42 and 43, it is possible to further improve the writing start position accuracy of the image.

Next, the operation of this embodiment will be described.

When a paper feed command is received, the film feeding device 30 of the film feeding unit 13 starts operating, and the vacuum suction disk 31
Contacts the uppermost film 16 in the cartridge 12 while maintaining a horizontal posture, and sucks the film 16 by vacuum. While maintaining this state, the sheet feeding arm 33 is rotated, and the leading end of one picked-up film 16 is moved to a position where the driven roller 34b is separated from the driving roller 34a.
It is inserted into the conveying roller pair 34. Next, the driven roller 34b moves and comes into pressure contact with the drive roller 34a, and the leading end of the film 16 is held by the first transport roller pair 34 and restrained. Next, the drive roller 34 a is driven to rotate, and the film 16 is fed along the guide plate 35 toward the second transport roller pair 36.

The film 16 transported in the lower horizontal transport area 17L is inserted into the third transport roller pair 37 in which the lower roller 37b has moved to the separated position, and the lower roller 37b is pressed against the upper roller 37a. As a result, it is held and restrained by the third transport roller pair 37. Next, the upper roller 37 a is driven to rotate, and the film 16 is fed toward the image forming unit 14. By detecting the rear end of the film 16 by the transport sensor SW1 provided upstream of the second transport roller pair 36, it is detected that the film 16 has reliably entered the lower horizontal transport area 17L.

When the leading end of the film 16 conveyed through the lower round conveyance area 18L and the lower vertical conveyance area 19L is inserted between the main drive roller pair 42, the film is conveyed by the main drive roller pair 42. To reduce the load,
The transport of the film 16 is released from the third transport roller pair 37, and the lower roller 37b is moved to a retracted position separated from the upper roller 37a.

The drive system 60 of the sub-scanning unit 41, that is, the main drive roller pair 42 and the sub drive roller pair 43, has already started to rotate when the film 16 enters the lower horizontal transport area 17L. By starting driving the driving system 60 of the sub-scanning unit 41 in advance in this way,
The starting torque of the sub-scanning motor M and the belt tension can be stabilized.

In the sub-scanning unit 41, the main drive roller pair 42 and the sub drive roller pair 43
And the film transporting force of the main drive roller pair 42 <the film transport speed of the slave drive roller pair 43>. The exposure unit 50 irradiates the laser beam L from the optical unit 40 to the film 16 which is conveyed in the vertical sub-scanning direction from the bottom to the top, sandwiched by the two drive roller pairs 42 and 43. Then, predetermined image information is recorded on the film 16.

Main drive roller pair 42 and slave drive roller pair 43
Are driven in the above relationship, the main drive roller pair 42 is driven to feed the film 16 without slipping, and the slave drive roller pair 43 is also driven to feed the film 16 without slipping by the action of the torque limiter 70. As a result, the influence of the drag (disturbance) on the film 16 on the upstream side or the downstream side of the sub-scanning unit 41 is reduced, so that extremely stable film transport can be realized. Accordingly, sub-scanning can be performed at a stable feeding speed with little fluctuation, and a high-quality image without uneven feeding can be recorded on the film 16.

The leading edge of the film 16 transported to the sub-scanning unit 41 is detected by a leading edge detection sensor SW2 disposed upstream of the main drive roller pair 42. By detecting the passage of the leading end of the film, the start timing of image formation is recognized.

The film 16 which has been subjected to the exposure process in the sub-scanning unit 41 passes through an upper vertical transport area 19U, an upper round transport area 18U and an upper horizontal transport area 17U, and undergoes a thermal development step as a next step. It is sent to the unit 15. Even when the film 16 is fed through the upper transport area 21, until the image formation in the sub-scanning unit 41 is completed, the fourth
No.-6 transport roller pairs 44, 45, 46 are not driven. Thereby, the transport load of the film 16 in the sub-scanning unit 41 is reduced as in the case of the lower transport area 20. After recognizing the end of image formation at a predetermined timing, the fourth transport roller pair 44 and the like provided in the upper transport area 21 are driven to drive the film 16 into the heat developing unit 1.
5 is carried out.

In the sub-scanning unit 41 which performs vertical conveyance, if the film conveyance drive in the next step is not started even after the image formation, the rear end of the film 16 is positioned between the pair of driven rollers 43. Will stay forever. Therefore, a pair of transport rollers 44 provided in the upper transport area 21,
After the transport driving of the film 16 by 45 and 46 is started, the sub-scanning motor M is stopped, and the driving of the main driving roller 42a and the sub driving roller 43a is stopped. As a result, the rear end of the film does not remain sandwiched between the pair of driven rollers 43.

The exposed film 16 sent to the heat developing section 15 is heat-developed by a heat roller 47, and then discharged by a discharge roller pair 48 onto a discharge tray 49 on the upper surface of the laser printer 10. You.

Since the film size used in the printer 10 of this embodiment is 8 inches to 18 inches, the rear end of the film when the leading end of the film is inserted between the main drive roller pair 42 has an 8 inch size. In the case of the film 16, the position of P1 in FIG.
In the case of, it comes to the position of P2 in the figure.

At this time, the weight of the 8-inch film 16 is applied to the sub-scanning unit 41 as a load.
Most of the weight of the 18-inch film 16 is received by the guide plates 22 and 23 of the lower transport area 20. Therefore, the load applied to the sub-scanning unit 41 is at most about the weight of the 8-inch film 16.

Even when the film 16 is transported by the drive roller pairs 42 and 43 of the sub-scanning unit 41 and covers both the lower transport area 20 and the upper transport area 21, the weight of the 8-inch film 16 is reduced. The load is applied to the sub-scanning unit 41 as a load. In the case of the 18-inch film 16, the weight of about 10 inches is reduced by the guide plates 22-provided in the lower transport area 20 and the upper transport area 21.
Thus, the effect of the 18-inch film 16 on the sub-scanning unit 41 can be reduced.

Even when the image formation in the sub-scanning unit 41 is completed and the film 16 reaches the upper transport area 21, the effect of the 18-inch film 16 on the sub-scanning unit 41 is reduced as described above. Can be.

It is necessary to consider the influence of the bending of the film 16 on the image due to the layout of the transport system in the apparatus. In the present embodiment, the influence is prevented by forming a 60 mm round shape. I have.

A pair of drive rollers 42 and 43 for transporting the film 16 in the vertical direction in the sub-scanning unit 41
By providing the upper transport area 21 and the lower transport area 20 formed substantially in parallel with each other along the substantially horizontal direction on the upper side and the lower side of the sub-scanning unit 41, the size of the printer 10 can be reduced. In particular, the floor area can be reduced.

Further, the posture of the film 16 is always stabilized, the constant speed of the transport speed is improved, and the image quality is good without uneven feeding. In addition, since the conveyance performance can be stabilized regardless of the length and size of the recording medium, it is particularly effective when conveying a recording medium having weight and thickness such as the photosensitive film 16. .

If the lengths of the lower transport area 20 and the upper transport area 21 are further reduced, the influence of the weight of the film 16 can be further reduced.

Further, if the radius is further increased,
The influence of the bending of the film 16 can be further reduced.

Further, if the length of each of the transport areas 20 and 21 is set to be at least half the length of the maximum length film 16 used in the printer 10, the floor area of the printer 10 can be further reduced. I can guide you. Also in this case, since the center of gravity of the film 16 to be conveyed is located in each of the conveyance areas 20 and 21, the conveyance stability of the film 16 is not hindered.

The printer 10 employs a toothed belt transmission system in which the motor pulley 61 and the main drive roller side pulley 62 are connected via a toothed belt 67 having high transmission efficiency. In this toothed belt transmission system, pulleys 61, 6
There is a problem that density unevenness (banding) occurs due to minute vibrations when the teeth of the belt 63 separate from the belt 2.

Therefore, in this embodiment, in order to eliminate the influence of the banding of the tooth pitch, the banding period is removed from the visual spatial frequency so that the banding becomes inconspicuous to human eyes. is there.

More specifically, the spatial frequency of vision is 0.6 to 1.2 cycles / mm at a viewing distance of 300 mm.
It is said that within the range, banding is easily felt due to the characteristics of human eyes. Where 0.6-1.2 cyc
Les / mm means 0.83 to 1.67 mm /
This means that banding is easily felt in the cycle.

Therefore, in order to eliminate the influence of the banding of the tooth pitch, in the power transmission to the main drive roller 42a, the speed reducing portion is provided in one step, that is, so as to minimize the factors causing the unevenness of the conveying speed. The motor M and the main drive roller 42a are connected by a belt 63 and pulleys 61 and 62.

Further, in order to remove the banding from the visual spatial frequency, the diameter D of the main drive roller 42a, the tooth pitch t of the belt 63, and the diameter D of the pulley 62 on the main drive roller side are set.
'(The number of teeth Z) is t (D / (t · Z / π)) <0.83, ie, t (D
/D′)<0.83 or t (D / (t · Z / π))> 1.67, ie, t (D
/D')>1.67 The specifications of the main drive roller pulley 62 are determined so as to satisfy the following relationship.

With this design, even if a toothed belt transmission system is adopted, the drive system 60 in which banding is difficult to see can be formed, and the torque transmission efficiency of the drive system 60 has been improved. With the improvement of the transmission efficiency, the drive system 60 of the sub-scanning unit 41 can withstand disturbance (load fluctuation) exerted by other systems, and the transport stability is improved. In other words, it is not necessary to be aware of the effect of the load fluctuation on the drive system 60 of the sub-scanning unit 41, and the configuration of other systems can be designed relatively freely. It is possible to reduce the number of points and cost.

Further, as long as the same design conditions as above are followed,
Even if a gear transmission system is adopted in place of the belt 63 and the pulleys 61 and 62, a drive system in which banding is difficult to see can be configured. In this case, the cost can be reduced because there is no belt.

FIG. 7 is a top view showing a main part of a sub-scanning unit according to another embodiment of the present invention, and FIG. 8 is a schematic perspective view showing a power transmission relationship of a drive system in the sub-scanning unit. In the sub-scanning unit 41 of this embodiment, in addition to the configuration of the drive system 60 described above, in order to attenuate the vibration of the sub-scanning motor M composed of a pulse motor, a damping torque limiter 75 as an attenuating member is provided. It is connected to the main drive roller 42a. Reference numeral “76” in the drawing indicates a fixing member that fixes the damping torque limiter 75.

The concept of attenuating the vibration of the sub-scanning motor M using the damping torque limiter 75 will be described. At first, the transmission system of the sub-scanning unit was considered to be a transmission system using gears from the viewpoint of cost.However, due to the large amount of play such as backlash, stable conveyance performance could not be obtained, and the small pulley and motor were directly connected. An eyelash drive method by pressure contact with a pulley was used. However, since the driving is performed by a simple method, the film is vulnerable to a large load change, and when a disturbance acts on the film being conveyed, the conveyance speed may be uneven.

Conventionally, in order to absorb the rotational speed fluctuation of the pulse motor, for example, as shown in Japanese Patent Application Laid-Open No. 4-292350, the shaft of the pulse motor and the shaft of the drive roller are connected to an elastic body such as an O-ring. There is proposed a system in which a flywheel is provided directly on the drive roller side via a drive roller.

However, in this method, if the pressing force of both shafts is large, the elastic constant of the O-ring increases and the vibration of the pulse motor cannot be attenuated. Is small, there is a disadvantage that the transmission speed of the motor is delayed even if the vibration of the pulse motor can be suppressed.

Further, since the effect of the flyhole is proportional to the square of the speed, it is effective when rotating at a relatively high speed, but a sub-scanning unit which needs a stable rotation at a relatively low speed. Not suitable for 41.

Further, since the shaft on the pulse motor side and the shaft of the driving roller are directly connected, there is a disadvantage that a large installation space is required in the axial direction.

On the other hand, as shown in FIGS. 7 and 8, in this embodiment, the pulse motor M and the driving roller 42a
Is not directly connected, so that a large installation space is not required in the axial direction.

Further, since no flywheel is required, the space for the flywheel is not required, and the weight of the entire printer 10 can be reduced by the weight of the flywheel.

Further, by applying a load, at least a fluctuation component caused by a load less than the load is reduced by the main drive roller 42.
Since there is no telling to a, a vibration which occurs at light load fluctuations due to back crash, it is possible to cut enough. Even when a load less than the load of the damping torque limiter 75 is applied, the main drive roller 42a does not move because it is restricted by the damping torque limiter 75.
As described above, the load equal to or less than the predetermined load value accompanying the driving of the sub-scanning motor M is attenuated by the action of the damping torque limiter 75, and the speed fluctuation of the main drive roller pair 42 is suppressed.
The transport stability of the film 16 in the exposure unit 50 is improved, and a high-quality image is recorded.

Further, in the sub-scanning unit 41 of this embodiment, the film 16 enters the sub-drive roller pair 43 by setting the torque value of the damping torque limiter 75 to be equal to or greater than the conveying force of the sub-drive roller 43a. The fluctuation in the speed of the film 16 that occurs when this occurs can also be suppressed. That is, as shown in FIG. 9A, the film 16 is fed by the main drive roller pair at a speed v1. As shown in FIG. 3B, the film 16 is
At the moment when the rotation speed reaches 3, since v1 <v2, the film is pulled toward the driven roller pair 43 side. Here, if there is play in the motor transmission system from the motor M to the main drive roller 42a, the film 16 will be fed at the speed v2 until the play is absorbed. On the other hand, in the present embodiment in which the damping torque limiter 75 is connected to the shaft of the main drive roller 42a, even if v1 <v2, the film restraining force is F1> F2. It is transported without becoming v2. in this way,
The effect of the damping torque limiter 75 suppresses a change in the film transport speed caused by the difference between the film transport speed of the main drive roller pair 42 and the film transport speed of the slave drive roller pair 43. The transport stability of the film 16 is improved, and a high-quality image is recorded.

In the above-described embodiment, the case where two pairs of rollers 42 and 43 are applied to the drive system 60 of the vertical transport type sub-scanning unit 41 has been described. Is applicable to the sub-scanning unit 41 of the parallel transport type.

Although the above-described embodiment has shown the case where the present invention is applied to an image recording apparatus, the present invention is not limited to this case. For example, the present invention can be widely applied to an image information processing apparatus having a processing unit that performs recording or reading by transporting a sheet-shaped recording medium, such as an image reading apparatus that reads image information and a photographing apparatus.

[0092]

As described above, according to the image information processing apparatus of the present invention, a recording medium is conveyed by two driving roller pairs having a relatively small diameter without using a relatively large-diameter drum. Accordingly, the drive system for transporting the recording medium in the processing unit is reduced, and the size of the apparatus can be reduced through the drive system.

Further, by driving the first and second driving roller pairs under a predetermined relationship, even if the recording medium is conveyed by the two driving roller pairs, the recording medium on the upstream side or the downstream side of the processing unit can be used. To the influence of the drag (disturbance) on the recording medium, and the conveyance stability of the recording medium in the processing unit is improved.
It becomes possible to record or read high-quality images.

Further, since the damping member is connected to the first driving roller pair, a load applied from a motor or the like that is equal to or less than a predetermined load value is attenuated, and the speed fluctuation of the first driving roller pair is suppressed. Fluctuation of the recording medium conveyance speed caused by the difference in the recording medium conveyance speed due to the above, the conveyance stability of the recording medium in the processing unit is further improved, and a higher quality image is recorded or read. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a side view showing an overall configuration of a laser printer according to an embodiment of an image information processing apparatus of the present invention.

FIG. 2 is a top view showing a positional relationship between a cartridge and a sub-scanning unit shown in FIG.

FIG. 3 is a side view illustrating a main part of a sub-scanning unit.

FIG. 4 is a top view showing a main part of the sub-scanning unit shown in FIG.

FIG. 5 is a schematic perspective view showing a power transmission relationship of a drive system in the sub-scanning unit.

FIGS. 6A and 6B are views for explaining the configuration of a driving roller.

FIG. 7 is a top view showing a main part of a sub-scanning unit according to another embodiment of the present invention.

8 is a schematic perspective view showing a power transmission relationship of a drive system in the sub-scanning unit shown in FIG.

FIGS. 9A and 9B are diagrams for explaining the operation of the damping torque limiter.

[Explanation of symbols]

10 ... laser printer (image information processing device), 16 ...
Photosensitive film (sheet-shaped recording medium), 41: sub-scanning unit, 42: main drive roller pair (first drive roller pair), 42a: main drive roller, 4
2b: opposing roller, 43: slave drive roller pair (second drive roller pair), 43a: slave drive roller
43b: opposing roller, 50: exposure unit (processing unit),
61: motor pulley, 63: first belt, 62: main drive roller side pulley, 75: damping torque limiter (damping member), M
... Sub-scanning motor (motor).

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tatsuro Oishi 2-3-13 Azuchicho, Chuo-ku, Osaka-shi Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Noboru Omoto, Aji-cho, Chuo-ku, Osaka-shi Chome 3-13 Osaka International Building Minolta Camera Co., Ltd. (56) References JP-A-2-152840 (JP, A) JP-A-2-292076 (JP, A) JP-A-63-258340 (JP, A) A) Hikaru Hira 3-38857 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B65H 5/06

Claims (1)

(57) [Claims] 1. An image information processing apparatus having a processing unit for performing recording or reading on a sheet-shaped recording medium to be conveyed, wherein a driving force is provided on an upstream side of the processing unit in the conveying direction of the recording medium. A first driving roller pair having a driving force, a second driving roller pair having a driving force is provided downstream of the processing unit along the transport direction of the recording medium, and the first driving roller pair and the second driving roller pair are provided. The driving roller pair, the recording medium conveying force by the first driving roller pair> the recording medium conveying force by the second driving roller pair, and the recording medium conveying speed by the first driving roller pair <the recording medium conveying by the second driving roller pair The first drive roller pair is driven at a speed lower than a predetermined load value.
An image information processing apparatus to which an attenuation member for attenuating a load is connected .