JP3052782B2 - Image forming 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 forming apparatus for conveying a recording sheet by using a plurality of rollers and forming an image on the recording sheet. And an image forming apparatus capable of transmitting a driving force to the image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, a plurality of rollers for conveying a recording sheet along a predetermined conveying path, and an image forming means for forming an image on the recording sheet conveyed to a predetermined image forming position on the conveying path. A driving source for generating a driving force for driving the plurality of rollers, and a driving force transmission for transmitting a driving force generated by the driving source to a part of the plurality of rollers according to a rotational position of a cam. An image forming apparatus including a unit and a cam driving unit that rotates the cam and switches the roller in which the driving force of the driving source is transmitted by the driving force transmitting unit is considered. In this type of image forming apparatus, the driving force generated by the driving source is selectively transmitted to some of the rollers, so that the load on the driving source can be reduced.

In this type of image forming apparatus, a cam position detecting means for detecting that the cam has rotated to a predetermined rotational position, and the cam driving means are controlled based on a detection result of the cam position detecting means. It is also considered that the plurality of rollers are sequentially driven along the transport path by providing a control unit that performs the control. In this case, the roller to which the driving force is transmitted is switched with the conveyance of the recording paper,
Image formation can be performed smoothly.

[0004]

However, when the cam is rotated to switch the roller to which the driving force is transmitted, the cam may or may not pass the predetermined rotational position during the switching operation. In some cases. If the control of rotating the cam without repeating the predetermined rotation position is repeated, a control error occurs in the rotation position of the cam, and it may be impossible to transmit the driving force to a desired roller. Therefore, an object of the present invention is to provide an image forming apparatus capable of preventing a control error from occurring in a rotational position of a cam and accurately switching a roller to which a driving force is transmitted.

[0005]

According to a first aspect of the present invention, there is provided an image forming apparatus, comprising: a plurality of rollers for conveying a recording sheet along a predetermined conveying path; Image forming means for forming an image on the recording paper conveyed to the forming position, a driving source for generating a driving force for driving the plurality of rollers, and A driving force transmitting means for transmitting a driving force generated by the driving source to a part thereof, and a cam driving means for rotating the cam to switch the rollers to which the driving force of the driving source is transmitted by the driving force transmitting means. A cam position detecting means for detecting that the cam has rotated to a predetermined rotational position; and controlling the cam driving means based on a detection result of the cam position detecting means to move the plurality of rollers to the transport path. To And a control means for sequentially driving the cams, wherein the cam position detecting means determines that the cam has rotated to a first rotational position and a second rotational position different from the first rotational position. It is individually detected that the cam has been rotated to the rotational position, and when the cam is rotated from the current position to the target position, it is determined whether or not the cam passes through the first rotational position or the second rotational position. Means, and when the determination means determines that the vehicle has passed, the control means detects the result of detection by the cam position detection means in accordance with the rotational position of the passage, that is, the detected rotation.
The shift position is the first rotation position or the second rotation position
Data on the cam position based on whether the
To a value corresponding to the rotational position detected by the
The cam drive means is controlled to rotate the cam to a target position .

According to a second aspect of the present invention, there is further provided a second conveying apparatus for conveying a document along a second conveying path different from the conveying path.
A roller, and document image reading means for reading an image of the document conveyed to a predetermined reading position on the second conveyance path, wherein the driving force transmitting means comprises A drive force generated by the drive source is transmitted to a part of the roller or the second roller, and the control means controls the cam drive means based on the detection results of the cam position detection means, 2. The image forming apparatus according to claim 1, wherein a plurality of rollers are sequentially driven along the transport path, or the second roller is driven.

According to a third aspect of the present invention, an image is formed on a plurality of rollers for transporting a recording sheet along a predetermined transport path and on the recording sheet transported to a predetermined image forming position on the transport path. An image forming unit, a driving source for generating a driving force for driving the plurality of rollers, and transmitting a driving force generated by the driving source to a part of the plurality of rollers according to a rotational position of a cam. A driving force transmitting unit, a cam driving unit for rotating the cam, and switching the roller in which the driving force of the driving source is transmitted by the driving force transmitting unit, and a cam driving unit for rotating the cam to a predetermined rotational position. An image comprising: a cam position detecting means for detecting; and a control means for controlling the cam driving means based on a detection result of the cam position detecting means to sequentially drive the plurality of rollers along the transport path. form In the apparatus, the cam position detecting means individually detects that the cam has rotated to a first rotation position and that the cam has rotated to a second rotation position different from the first rotation position, The control means controls the cam drive means based on the respective detection results of the cam position detection means, and the cam has a cam surface on which two grooves having different lengths are formed, and the cam position detection means The displacement means is disposed to face the cam surface and is displaced in the groove direction when facing the groove. When the displacement part is displaced in the groove direction during rotation of the cam, the displacement is continued. A detection unit that detects that the cam has rotated to the first rotation position or the second rotation position according to a period.

According to a fourth aspect of the present invention, the control means includes:
The image forming apparatus according to claim 3, wherein before and after the displacement portion faces the groove, a rotation speed of the cam by the cam driving unit is reduced.

[0009]

According to the first aspect of the present invention, the cam position detecting means determines that the cam has rotated to the first rotational position and that the cam position detecting means is different from the first rotational position. 2 is detected individually. The judging means, when rotating the cam from the current position to the target position, the first rotation position or the second rotation position.
It is determined whether or not the vehicle passes through the rotational position, and when the determination unit determines that the vehicle passes, the control unit detects the cam position detecting unit according to the rotational position through which the vehicle passes ,
That is, the detected rotation position is the first rotation position.
Or the second rotational position , the cam position is determined.
Rotation position detected by the cam position detection means
After adjusting the cam to the target position,
The cam driving means is controlled to rotate. Therefore, every time the cam passes through the first rotation position or the second rotation position, it is possible to correct the control error of the rotation position of the cam. Therefore, the chance of correcting the control error of the rotational position of the cam increases, so that it is possible to prevent the control error from occurring in the rotational position of the cam and to accurately switch the roller to which the driving force is transmitted. it can.

According to a second aspect of the present invention, in addition to the configuration of the first aspect of the present invention, a second transport path different from the transport path is further provided.
A second roller that conveys the document along the conveyance path, and a document image reading unit that reads an image of the document conveyed to a predetermined reading position on the second conveyance path, wherein the driving force transmission unit includes: In accordance with the rotation position of the cam, the driving force generated by the driving source is transmitted to a part of the plurality of rollers or the second roller, and the control unit transmits the driving force generated by the cam position detection unit to each of the detection results. The cam driving means is controlled based on the control signal to sequentially drive the plurality of rollers along the transport path or to drive the second roller. In this type of apparatus, an original can be transported using the second roller, and an image on the original can be read. Further, in this type of apparatus, when forming an image on recording paper by the image forming means, it is not necessary to drive the second roller at all, or when reading the image of the original by the original image reading means, In some cases, the roller need not be driven at all. For this reason, the effect of transmitting the driving force to the second roller or a part of the plurality of rollers to reduce the load on the driving source becomes more remarkable.

In this case, the number of modes (for example, control modes) for transmitting the driving force to the second roller or a part of the plurality of rollers is increased. Therefore, the necessity of preventing a control error from occurring in the rotational position of the cam increases. Therefore,
According to the present invention, the effect of the invention described in claim 1 becomes more remarkable.

According to the third aspect of the present invention, the cam position detecting means determines that the cam has rotated to the first rotational position and that the cam has rotated to the second rotational position different from the first rotational position. The detection is individually performed, and the control means controls the cam driving means based on each detection result of the cam position detection means. Therefore, every time the cam passes through the first rotation position or the second rotation position, it is possible to correct the control error of the rotation position of the cam. Therefore, the chance of correcting the control error of the rotational position of the cam increases, so that it is possible to prevent the control error from occurring in the rotational position of the cam and to accurately switch the roller to which the driving force is transmitted. it can. Further, in the present invention, the cam has a cam surface on which two grooves having different lengths are formed, and the cam position detecting means is arranged to face the cam surface, and displaces in the groove direction when facing the groove. When the displacement portion is displaced in the groove direction during rotation of the cam, the cam is rotated to the first rotation position or the second rotation position depending on the duration of the displacement. And a detecting unit for detecting. For this reason, the cam position detecting means is realized by a mechanical configuration having the above-mentioned displacement portion, and the configuration is extremely simplified. Therefore, according to the present invention, in addition to the effects of the first and second aspects of the invention, an effect of simplifying the configuration of the device is produced.

According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, the control means reduces the rotational speed of the cam by the cam driving means before and after the displacement portion faces the groove. It is characterized by: For this reason, it is possible to accurately detect the period during which the displacement of the displacement portion has continued, and the first
And the second rotational position can be accurately determined. Therefore, in addition to the effect of the invention described in claim 3,
It is possible to more effectively prevent a control error from occurring in the rotational position of the cam, and to more accurately switch the roller to which the driving force is transmitted.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing an internal mechanism of a facsimile apparatus 2 according to an embodiment to which the present invention is applied.

Note that the facsimile apparatus 2 of the present embodiment
A facsimile transmission function for reading an image from the original 4 and transmitting the image data to another facsimile device via a telephone line, and receiving and recording image data transmitted from the other facsimile device via the telephone line It has a facsimile reception function of forming an image on paper 6 and a copying function of forming an image on recording paper 6 based on image data read from document 4.

As shown in FIG. 1, an operation panel 14 is provided at the front of the upper surface of the facsimile machine 2. Further, a recording paper cassette 16 is stored at the bottom of the facsimile machine 2. The recording paper cassette 16 is a well-known recording paper cassette having a recording paper support plate 18 on which the recording paper 6 is placed, which is urged upward by a spring (not shown). Further, a document table 20 on which the document 4 to be read is placed is formed at the center of the upper surface of the facsimile machine 2.

On the other hand, inside the facsimile apparatus 2, a scanner unit 22 for reading an image from the original 4 placed on an original table 20 and an image for forming an image on the recording paper 6 stored in the recording paper cassette 16. And a control unit 100 that drives and controls these units to realize the above functions.

In the scanner section 22, the documents 4 placed on the document table 20 are taken in one by one by separation rollers 32. The original 4 is transported by the transport rollers 33a and 33b.
The document is conveyed to the document support plate 34 by the image reading device 35, and the image on the front surface is read by an image reading device 35 disposed below the document support plate 34. The document 4 after the image reading is discharged to the front of the facsimile machine 2 via the discharge rollers 36a and 36b. The image reading device 35 irradiates the document 4 with light, and condenses the reflected light from the document 4 on a light receiving surface such as a line image sensor (not shown).
It is a well-known one that reads an original image one line at a time.

On the other hand, in the recording section 26, the recording paper support plate 18
The recording paper 6 placed thereon is taken in one by one by a paper feed roller 51. Then, the recording paper 6 is sent between the platen roller 55 and the thermal head 57 via the transport rollers 53a and 53b, and an image is formed. Also,
The recording paper 6 after image formation is discharged to the front of the facsimile machine 2 via the discharge rollers 59a and 59b. An ink ribbon 69 that is transported from the ribbon supply drum 61 to the ribbon take-up drum 67 via the support rollers 63 and 65 is provided between the platen roller 55 and the thermal head 57. The thermal head 57 attaches the support roller 6 to the recording paper 6 disposed on the platen roller 55.
This is a known method in which an ink image is formed on the surface of the recording paper 6 by heating and pressing an ink ribbon 69 provided between the recording papers 6 and 65.

Next, each of the rollers 32, 33a, 36
The a, 51, 53a, 55, 59a and the ribbon winding drum 67 are driven by a pulse motor 80 via a gear mechanism 70 shown in FIG. Hereinafter, this gear mechanism 7
The configuration and operation of 0 will be described with reference to FIGS. In FIGS. 2 to 8, gears that rotate and transmit torque to other gears are indicated by solid arrows, and the gears that are rotating themselves but transmit torque to other gears are shown in FIGS. The gears that are not shown are indicated by the dashed arrows indicating the direction of rotation.

As shown in FIG. 2, a gear 71a fixed to the rotating shaft of the pulse motor 80 meshes with a large diameter portion of a gear 71b in which two large and small spur gears are integrated. Further, it meshes with the large diameter portions of the gears 71c and 71k. A lever 73c is swingably fixed to the rotation shaft of the gear 71c, and one end of the lever 73c is provided with a gear 71d that meshes with a small diameter portion of the gear 71c. That is, the gear 71d is a so-called planetary gear, and the gear 71c rotates clockwise in the figure (hereinafter referred to as clockwise).
, The gear 71d rotates counterclockwise in the figure (hereinafter referred to as counterclockwise), and the gear 73c, 71d meshes, whereby the lever 73c swings clockwise. For this reason,
The gear 71d meshes with the outer periphery of the cam 75, and transmits clockwise rotational force to the cam 75.

On the other hand, a lever 73 is provided on the rotating shaft of the gear 71b.
b is swingably fixed, and a gear 71o meshing with the small diameter portion of the gear 71b is provided at one end thereof. Therefore, when the gear 71b rotates counterclockwise, the lever 73b swings counterclockwise, and the pin 77b at the other end of the lever 73b is locked by the cylindrical locking portion 79 formed at the center of the cam 75. . Therefore, the gear 71o does not transmit the rotational force to any other gear.

The gear 71k is formed by integrating three large and small spur gears.
k is rotatably arranged. A gear 71v is provided at one end of the lever 73k so as to mesh with the small diameter portion of the gear 71k. When the gear 71k rotates clockwise, the lever 73k is rotated.
Also swings clockwise. For this reason, the other end of the lever 73k has a locking piece 8 fixed to the housing of the facsimile machine 2.
Engage with 1. Therefore, gear 71v does not transmit torque to any other gear.

The medium diameter portion of the gear 71k meshes with the large diameter portion of the gear 71l. A lever 73l is provided on the rotating shaft of the gear 71l.
Is rotatably fixed, and a gear 71m meshing with a small diameter portion of the gear 71l is provided at one end of the lever 73l. The other end of the lever 73l is connected to the facsimile device 2
Is engaged with one end of a lever 73m that swings around a shaft 83 fixed to the housing. By driving the pulse motor 80 clockwise (CW rotation), the cam 75 can be rotated. At this time, the rollers 32, 33a, 36a, 51, 53a,
55, 59a and the gears 71j, 71i, 71h, 71n, 71z, 7 which rotate integrally with the ribbon winding drum 67.
No rotational force is transmitted to 1u, 71x, and 71r. Hereinafter, this mode is called a cam drive mode.

As shown in FIG. 3, on the back surface of the cam 75,
A cam groove 85 is formed to be engaged with a pin 77m formed at the other end of the lever 73m. This cam groove 85 is
5 has a proximity portion 85a close to the rotation axis and a separation portion 85b separated from the rotation axis. A cam surface 8 having a first groove 87a and a second groove 87b is provided on the back surface of the cam 75.
7 is formed, and the limit switch 89 in which the operating piece 89a is brought into contact with the outer periphery of the cam surface 87 is connected to the facsimile machine 2.
Is fixed to the housing. The first groove 87a and the second groove 87b have different circumferential lengths.

In the cam drive mode, the pulse motor 80 is rotated counterclockwise after the operating piece 89a of the limit switch 89 is rotated to a rotational position at which it engages with the first groove 87a (hereinafter, this rotational position is referred to as a first origin). (The CCW rotation), the driving force of the pulse motor 80 is transmitted as follows.

That is, as shown in FIG.
, The counterclockwise rotational force is transmitted to the gear 71c, the lever 73c swings counterclockwise, and the gear 71d meshes with the large diameter portion of the gear 71f. A gear 71g meshes with the small diameter portion of the gear 71f, and the gear 71
h, 71i, and a gear 71j is meshed with the gear 71i. For this reason, the rotational force of the gear 71d
The gears are transmitted to gears 71h, 71i, and 71j via f and 71g.

On the other hand, when the gear 71b rotates clockwise, the lever 73b also swings clockwise.
Engages with a cam ridge 91 formed on the surface of the cam 75.
Therefore, the gear 71o does not transmit the rotational force to any gear. Also, by rotating the gear 71k counterclockwise,
The lever 73k swings counterclockwise, and the gear 71v
w. Since the gears 71w, 71x, 71y, and 71z are sequentially meshed, the rotational force of the gear 71v is
w to 71z. By driving the pulse motor 80 in this manner, the separation roller 32, the transport roller 33a, and the paper discharge roller 36a of the scanner unit 22 can be driven to read the document image by the image reading device 35. At this time, the transport rollers 53 of the recording unit 26
a, the paper discharge roller 59a also rotates. This mode is called a reading mode.

Next, the cam 75 is again rotated in the cam drive mode, and the pin 77m is engaged with the adjacent portion 85a of the cam groove 85, and then the pulse motor 80 is rotated CCW.
The operation in the paper feed mode shown in FIG. 5 is performed. In this mode, when the lever 73c swings counterclockwise,
Since the pin 77c of c contacts the outer periphery of the cam ridge 92, the gear 71d does not mesh with the gear 71f. Therefore, the separation roller 32, the conveyance roller 33a, and the paper discharge roller 36a of the scanner unit 22 do not rotate. Since the pin 77b is engaged with the cam ridge 91 as in the reading mode, the gear 71o does not transmit the rotational force to any gear.

On the other hand, when the pin 77m is engaged with the proximity portion 85a, the lever 73m swings counterclockwise. For this reason, the range in which the lever 73l can swing increases. A clockwise rotation force is transmitted to the gear 711 via the gears 71b and 71k, and a force for swinging the lever 73l clockwise acts. Therefore, the gear 71m is changed to the gear 71n.
And the rotational force is also transmitted to the paper feed roller 51 of the recording unit 26. Further, a rotational force is transmitted to the transport roller 53a and the paper discharge roller 59a of the recording unit 26 in the same manner as in the above-described reading mode.

FIG. 6 shows the state of transmission of the driving force in the recording mode. In this mode, after the cam 75 is rotated to a rotational position (hereinafter, this rotational position is referred to as a second origin) at which the operating piece 89a (see FIG. 3) of the limit switch 89 engages with the second groove 87b, This is executed by rotating the pulse motor 80 CCW. In this mode, the pin 77c of the lever 73c engages with the cam ridge 92, and each of the rollers 32 to 36a of the scanner unit 22 similarly to the above-described paper feed mode.
Does not rotate. Further, since the pin 77m of the lever 73m is engaged with the separation portion 85b of the cam groove 85, the paper feed roller 51 does not rotate as in the above-described reading mode.

On the other hand, in this mode, the pin 77b of the lever 73b does not engage with the cam ridge 91. Thus, the lever 73b swings clockwise, and the gear 71o meshes with the gear 71p. The gear 71p meshes with the small-diameter portion of the gear 71q, and the small-diameter portion of the gear 71q and the gears 71s and 71g.
t and the gear 71u are sequentially meshed. Also, the gear 71q
Is in mesh with the gear 71r. Therefore, the gear 7
The rotation force of 1o is applied to the gear 71p, the gear 71q, and the gear 71.
s and the gear 71u via the gear 71t, and to the gear 71r via the gears 71p and 71q. For this reason, the platen roller 55 (integral with the gear 71u) and the ribbon winding drum 67 (the gear 71
) rotates clockwise, and image formation using the thermal head 57 becomes possible.

FIG. 7 shows the state of transmission of the driving force in the paper discharge mode. In this mode, the pin 77c of the lever 73c is engaged with the cam ridge 93 having the same diameter as the cam ridge 92. Therefore, similarly to the above-described paper feed mode, the scanner unit 2
The second rollers 32 to 36a do not rotate. Also, the pin 77b of the lever 73b engages with the cam ridge 91,
Since the pin 77m is engaged with the spaced portion 85b of the cam groove 85, the platen roller 55, the ribbon winding drum 6
7, and the paper feed roller 51 also does not rotate. Therefore, only the transport roller 53a and the paper discharge roller 59a of the recording unit 26 rotate.

FIG. 8 shows the transmission state of the driving force in the copy mode. In this mode, the pin 77c of the lever 73c does not engage with the cam ridge 92 or the cam ridge 93. For this reason, the rotation force is transmitted from the gear 71d to the gear 71f, and the scanner unit 2 is transmitted similarly to the above-described reading mode.
Each of the rollers 32 to 36a rotates. Also, lever 7
Since the pin 77b of 3b does not engage with the cam ridge 91, the torque is transmitted from the gear 71o to the gear 71p. Therefore, similarly to the above-described recording mode, the platen roller 55
And the ribbon winding drum 67 rotates. Lever 73m
Since the pin 77m is engaged with the separation portion 85b of the cam groove 85, the rotation force is not transmitted from the gear 71m to the gear 71n, and the sheet feeding roller 51 does not rotate. Therefore, in this mode, the reading of the document image by the image reading device 35 and the image formation by the thermal head 57 can be executed simultaneously.

As described above, in the gear mechanism 70 of this embodiment, the mode is changed by rotating the cam 75 to a desired position in the cam drive mode, and the rollers and the like to which the driving force of the pulse motor 80 is transmitted are changed. It can be switched in various ways. For example, when image data is formed on a plurality of recording papers 6, an image is sequentially formed on each recording paper 6 while alternately repeating a paper feed mode and a recording mode, and the last recording paper 6 is formed.
When the image is formed on the recording paper 6, the recording paper 6 can be completely discharged by switching to the paper discharge mode. Therefore, by supplying the driving force of the pulse motor 80 to only the necessary rollers 32 to 59a, power consumption is saved, and the ribbon winding drum 67 is constantly rotated, so that the ink ribbon 69 is unnecessarily consumed. Can be prevented.

Next, the control unit 100 is configured as shown in FIG. The control unit 100 controls the image reading device 35 and the pulse motor 80 in response to a facsimile transmission command or the like of the document 4 input by the user operating the operation panel 14, or controls the image reading device 35 or The CPU 101, the ROM 103, and the RAM 10 control the thermal head 57 and the pulse motor 80 based on data transmitted from a telephone line described later.
5 is configured as a well-known microcomputer.

The control unit 100 has a network control unit (NCU) for connecting an external telephone line to the apparatus and enabling communication and transmission / reception of image data with another telephone or facsimile apparatus. 107, and a modem 109 for transmitting and receiving image data to and from another facsimile device via the NCU 107. The CPU 101 transmits image data to another facsimile device via a telephone line, It also performs communication control for receiving image data transmitted from another facsimile machine via a telephone line.

The CPU 101, ROM 103, RA
M105, NCU 107 and modem 109 are connected to a bus 111
The bus 111 is connected to the operation panel 14, the image reading device 35, the thermal head 57, the pulse motor 80, and the limit switch 8.
Input / output port 11 that enables input and output of data with 9 etc.
3 is also connected.

Next, when changing the rotation position of the cam 75 (hereinafter referred to as the cam position) in the cam drive mode,
The cam position changing process executed by U101 will be described. FIG.
0 is a flowchart showing the cam position changing process. As shown in FIG.
First, in S10, the mode corresponding to the current cam position and the mode to be changed are read. In S20, when the cam 75 is rotated from the current position to the target position according to the mode to be changed, the cam 75 passes through the above-mentioned first origin or second origin (in the case where there is no need for distinction, simply referred to as the origin). It is determined whether or not. When not passing through the origin (S20:
(NO) shifts to S30. In S30, the pulse motor 80 is driven at a high speed of 800 PPS to rotate the cam 75 to the target position, and the process ends. Note that S30
When the pulse motor 80 is rotated at high speed, the so-called slow-up / slow-down operation is performed in which the number of pulses is gradually increased to 800 PPS, and the number of pulses is gradually reduced even when the motor is stopped, instead of driving at 800 PPS from the beginning. .
The determination as to whether the cam position has reached the target position is made by storing the number of pulses output to the pulse motor 80 in the RAM 105 and converting the stored number of pulses into a rotation angle.

When the vehicle passes through the origin (S20: YE)
S) proceeds to S40 to determine whether the current cam position is near the origin (for example, within a range of a predetermined angle from the origin). If not near the origin (S40: NO), S
The process proceeds to S50, where the pulse motor 80 is driven at a high speed of 800 PPS as in S30, and the process proceeds to S40 again. As described above, the pulse motor 80 is rotated at high speed until the cam position reaches the vicinity of the origin.
YES) Go to S60.

In step S60, the pulse motor 80 is driven at a low speed of 400 PPS. In subsequent S70, it is determined whether or not the origin has been detected via the limit switch 89. If the origin has not been detected (S70: NO), S60 is performed again.
Move to. Thus, the pulse motor 80 is rotated at a low speed until the origin is detected, and the origin is detected (S70:
YES) Proceed to S80. In S80, the RAM 105
Then, the data relating to the cam position (for example, the number of output pulses to the pulse motor 80) stored in the memory is corrected to a value corresponding to the detected origin, and the process proceeds to S30. As described above, the first groove 87a and the second groove 87b have different circumferential lengths. Therefore, whether the origin detected in S70 is the first origin or the second origin is determined based on the duration of the detection signal from the limit switch 89.

As described above, in the above embodiment, the fact that the cam 75 has rotated to the first origin and the fact that it has rotated to the second origin different from the first origin are individually detected, and the detected origin is determined. The cam position data is corrected accordingly. Therefore, the cam position data can be corrected every time the cam 75 passes through the first origin or the second origin. Therefore, the opportunity to correct the cam position data increases, and furthermore, it is possible to prevent an error from occurring in the cam position data, and to transmit the driving force of the pulse motor 80 to the rollers 32 to 59a or the ribbon winding drum 67. Can be accurately switched.

Further, in the above embodiment, the cam 75 has the cam surface 87 having the first groove 87a and the second groove 87b, and the cam piece 87a of the limit switch 89 is engaged with and displaced according to the period. Thus, the first origin and the second origin are individually detected. For this reason, the configuration for detecting the first origin and the second origin can be simplified, and thus the configuration of the entire apparatus can be simplified. Note that the configuration for detecting the first origin and the second origin is not limited to that of the above-described embodiment.
For example, like a combination of a magnet and a Hall element,
A configuration for performing non-contact detection may be employed.

Further, in the above embodiment, when the cam 75 has reached the vicinity of the origin (S40: YES), the pulse motor 80 is driven at a low speed (S60). Therefore, the first origin,
The second origin can be detected more accurately, the correction of the cam position data in S80 can be made more accurate, and the above modes can be switched more accurately.

In the above embodiment, the rollers 53b
To 59b are the rollers of claim 1, rollers 32 to 36a are the second rollers, the thermal head 57 and the ink ribbon 69 are the image forming means, the pulse motor 80 is the driving source,
The gear mechanism 70 serves as driving force transmitting means, the pulse motor 80 and the gears 71a to 71d serve as cam driving means, the limit switch 89 and the control unit 100 serve as cam position detecting means,
The control unit 100 serves as a control unit, the image reading device 35 serves as a document image reading unit, the operation piece 89a serves as a displacement unit, and the origin detected in S70 executed in S80 is the first origin or the second origin. The process of determining whether or not there is a process corresponds to the detecting unit, and the process of S20 corresponds to the determining unit.

Further, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist of the present invention. For example, in the above embodiment, the cam 75 is rotated by the driving force of the pulse motor 80, but a driving motor for the cam 75 may be provided separately. However, in the above embodiment, the number of components can be reduced as compared with this case, and the cost of the apparatus can be reduced.

The present invention can also be applied to a printer that does not include the scanner unit 22 and has only the same configuration as the recording unit 26. However, the facsimile apparatus 2 of the above embodiment includes the scanner unit 22 and the recording unit 26, and the rollers 32 to 59a belonging to any one of them.
There is a mode in which only the drive is required. Therefore, the effect of reducing the load on the pulse motor 80 by transmitting the driving force to only some of the rollers 32 to 59b via the gear mechanism 70 becomes more remarkable. Further, in the case of the facsimile machine 2, since it is necessary to switch to a number of modes as described above, it is necessary to control the cam position more accurately. Therefore, the effect of correcting the cam position data based on the first and second origins becomes more remarkable.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an internal structure of a facsimile apparatus according to an embodiment.

FIG. 2 is an explanatory diagram illustrating a driving force transmission state in a cam driving mode according to the embodiment.

FIG. 3 is a rear view illustrating a configuration of a cam of the facsimile apparatus according to the embodiment.

FIG. 4 is an explanatory diagram illustrating a transmission state of a driving force in a reading mode according to the embodiment.

FIG. 5 is an explanatory diagram illustrating a transmission state of a driving force in a sheet feeding mode according to the embodiment.

FIG. 6 is an explanatory diagram illustrating a transmission state of a driving force in a recording mode according to the embodiment.

FIG. 7 is an explanatory diagram illustrating a transmission state of a driving force in a paper discharge mode according to the embodiment.

FIG. 8 is an explanatory diagram illustrating a driving force transmission state in a copy mode according to the embodiment.

FIG. 9 is a block diagram illustrating a configuration of a control unit according to the embodiment.

FIG. 10 is a flowchart illustrating a cam position changing process according to the embodiment.

[Explanation of symbols]

2 facsimile apparatus 4 original 6 recording paper 14 operation panel 22 scanner unit 26
Recording unit 32: separation rollers 33a, 33b, 53a, 53
b: transport roller 35: image reading device 36a, 36b, 59a, 5
9b: paper discharge roller 51: paper feed roller 55: platen roller 5
7 Thermal head 67 Ribbon winding drum 69 Ink ribbon
70 gear mechanism 75 cam 80 pulse motor 87 cam surface 87a first groove 87b second groove 89 limit switch 89a operating piece 91, 92, 93 cam cam 10
0 ... Control unit

Claims (4)

(57) [Claims] A plurality of rollers for conveying a recording sheet along a predetermined conveyance path; an image forming means for forming an image on the recording sheet conveyed to a predetermined image forming position on the conveyance path; A driving source for generating a driving force for driving the plurality of rollers; a driving force transmitting unit for transmitting a driving force generated by the driving source to a part of the plurality of rollers in accordance with a rotational position of a cam; Cam driving means for rotating the cam to switch the roller, in which the driving force of the driving source is transmitted by the driving force transmitting means; and cam position detecting means for detecting that the cam has rotated to a predetermined rotational position. A control unit that controls the cam drive unit based on the detection result of the cam position detection unit to sequentially drive the plurality of rollers along the transport path. The cam position detecting means individually detects that the cam has rotated to a first rotational position and that the cam has rotated to a second rotational position different from the first rotational position. When rotating from the position to the target position, the apparatus further includes a determination unit that determines whether the vehicle passes through the first rotation position or the second rotation position. If the determination unit determines that the vehicle passes the rotation, The detection result of the cam position detecting means according to the rotational position passing through the control means, that is, the detected rotational position is the
Based on whether the rotation position is the first rotation position or the second rotation position, data on the cam position is detected by the cam position detection means.
After correcting to the value corresponding to the detected rotational position,
An image forming apparatus for controlling the cam driving means to rotate the cam to a target position . A second roller for transporting the document along a second transport path different from the transport path; and a document for reading an image of the document transported to a predetermined reading position on the second transport path. An image reading unit, wherein the driving force transmitting unit transmits a driving force generated by the driving source to a part of the plurality of rollers or the second roller according to a rotation position of a cam; A control unit that controls the cam driving unit based on each detection result of the cam position detection unit to sequentially drive the plurality of rollers along the transport path or to drive the second roller The image forming apparatus according to claim 1, wherein: 3. A plurality of rollers for transporting a recording sheet along a predetermined transport path; an image forming means for forming an image on the recording sheet transported to a predetermined image forming position on the transport path; A driving source for generating a driving force for driving the plurality of rollers; a driving force transmitting unit for transmitting a driving force generated by the driving source to a part of the plurality of rollers in accordance with a rotational position of a cam; Cam driving means for rotating the cam to switch the roller, in which the driving force of the driving source is transmitted by the driving force transmitting means; and cam position detecting means for detecting that the cam has rotated to a predetermined rotational position. A control unit that controls the cam drive unit based on the detection result of the cam position detection unit to sequentially drive the plurality of rollers along the transport path. The cam position detecting means individually detects that the cam has rotated to a first rotational position and that the cam has rotated to a second rotational position different from the first rotational position. Controlling the cam driving means based on each of the detection results of the cam position detecting means, wherein the cam has a cam surface on which two grooves having different lengths are formed, and the cam position detecting means comprises: A displacement portion that is disposed to face the cam surface and is displaced in the groove direction when facing the groove; and, when the displacement portion is displaced in the groove direction during rotation of the cam, according to a period during which the displacement continues. A detection unit that detects that the cam has rotated to the first rotation position or the second rotation position. 4. An image forming apparatus according to claim 3, wherein said control means reduces the rotation speed of said cam by said cam driving means before and after said displacement portion faces said groove.