JP2927618B2 - Gear mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus such as a facsimile apparatus, and more particularly to a recording apparatus having a structure in which a roll-shaped recording sheet and a sheet-shaped recording sheet can be selectively used as required. It is.

[0002]

2. Description of the Related Art Conventionally, a facsimile apparatus is known as an example of a recording apparatus. This facsimile machine
The original is optically scanned, converted into an electric signal and transmitted, and a receiver that operates in synchronization with the transmitter performs recording according to the received signal. Then, when recording the received data, the facsimile apparatus uses a roll-shaped recording paper,
When used as a simple copy, there is a type that uses sheet-shaped recording paper. A gear mechanism shown in FIGS. 23 and 24 is used as a mechanism for switching between roll-shaped recording paper and sheet recording paper.

The sun gear 103 is rotatably held on a rotating shaft 105. A first tooth portion 107 is provided on a part of the outer periphery of the sun gear 103. A planet gear arm 109 is rotatably held on the shaft 105. A planet gear 113 is rotatably held on a shaft 117 provided on the planet gear arm 109. A second tooth portion 115 is provided on the outer periphery of the planetary gear 113. Reference numeral 111 denotes a stopper for controlling the position of the planet gear arm 109.

A position adjusting projection 1 is provided on the outer periphery of the sun gear 103.
19 are provided. The position adjusting protrusion 119 is provided before the first tooth portion 107 and the second tooth portion 115 mesh with each other.
By moving the second tooth portion 115 to a predetermined position in contact with the first tooth portion 15, the first tooth portion 107 and the second tooth portion 115 can be smoothly engaged with each other. That is, when the first teeth 107 and the second teeth 115 engage with each other, the first teeth 1
When the top of 07 and the top of the second tooth portion 115 abut, the sun gear 103 and the planetary gear 113 are locked, and both gears cannot rotate. Therefore, by moving the second tooth portion 115 to a predetermined position using the position adjusting projection 119, when the first tooth portion 107 and the second tooth portion 115 are engaged with each other, the top of the first tooth portion 107 and the second The contact with the top of the tooth portion 115 is prevented.

[0005]

However, as shown in FIG. 24, when the second tooth portion 115 is moved to a predetermined position by the position adjusting protrusion 119, the top of the position adjusting protrusion 119 and the second tooth portion 115 are moved. The top may come into contact. Since the height of the position adjusting protrusion 119 is smaller than the height of the first tooth portion 107, the sun gear 103 and the planetary gear 113 are not locked by contact, and the position adjusting protrusion 119 and the second tooth portion 1 are not locked.
15 and the planetary gear 1 while deforming
13 rotates so that the second tooth portion 115 comes to a predetermined position.

The top of the position adjusting projection 119 and the second tooth 11
When the sun gear 103 and the planetary gear 113 rotate in a state where the top of the fifth gear 5 is in contact with the top, the position adjusting protrusion 119 and the second
The teeth 115 were overloaded and were sometimes worn or chipped.

Further, when the contact between the top of the position adjusting projection 119 and the top of the second tooth portion 115 is released, noise is generated due to release of the torque load.

The present invention has been made to solve such a conventional problem. An object of the present invention is to allow the sun gear and the planetary gear to rotate smoothly even if the top of the position adjusting projection provided on the sun gear and the top of the second tooth portion provided on the planetary gear abut. The purpose is to provide a gear mechanism.

[0009]

According to a first aspect of the present invention, there is provided a sun gear having first teeth formed only on a part of its outer periphery, a planetary gear arm provided coaxially with the sun gear,
A planetary gear, which is located around the sun gear, is rotatably held by the planetary gear arm and meshes with the first tooth portion, has a second tooth portion formed on the outer periphery thereof. The sun gear has the first
Position adjustment projections are provided to abut on the second teeth before the teeth engage with the second teeth to adjust the position of the second teeth. A first aspect of the present invention is characterized in that a planetary gear is loosely fitted to a planetary gear arm.

A second aspect of the present invention is the first aspect of the present invention.
In addition to the aspects described above, the planetary gear arm is further provided with biasing means for biasing the planetary gear toward the sun gear.

[0011]

According to the first aspect of the present invention, the planetary gear is loosely fitted to the planetary gear arm. The gear moves to the side opposite the side where the sun gear is located.
For this reason, even if the top of the position adjustment protrusion and the top of the second tooth portion abut, no excessive load is applied to the position adjustment protrusion and the second tooth portion.

According to a second aspect of the present invention, the first aspect further comprises an urging means for urging the planetary gear toward the sun gear. Thereby, even if the planetary gear is loosely fitted to the planetary gear arm, the meshing between the first tooth portion and the second tooth portion can be stabilized.

[0013]

(First Embodiment) FIG. 1 is a front view of a first embodiment of a gear mechanism according to the present invention. The gear mechanism 51
A sun gear 52 and a planet gear 58 rotatably held by a planet gear arm 55 and meshing with the sun gear 52 are provided.

The first tooth portion 5 is provided on a part of the outer periphery of the sun gear 52.
3 are provided, and a position adjusting projection 54 is provided on the outer periphery. The sun gear 52 rotates about a rotation shaft 56. The planet gear arm 55 is rotatably held about a rotation shaft 56. 57 is a stopper for controlling the position of the planetary gear arm 55.

Rotary shaft 6 provided on planetary gear arm 55
A planetary gear 58 is loosely fitted to 1. Since the planetary gear 58 is loosely fitted to the rotating shaft 61, there is a play 60. The loose fit is achieved by providing a difference between the diameter of the hole provided in the planetary gear 58 and the diameter of the rotating shaft 61. A second tooth portion 59 is provided on the outer periphery of the planet gear 58.

The operation of the first embodiment of the gear mechanism according to the present invention will be described below. As shown in FIG. 1A, when the sun gear 52 rotates in the direction of the arrow, the top of the position adjusting projection 54 and the top of the second tooth portion 59 abut. When the sun gear 52 further rotates in this state, the planet gear 58 moves in the direction of arrow A as shown in (2), and the sun gear 52 and the planet gear 58 rotate. Even if the top of the position adjusting protrusion 54 and the top of the second tooth portion 59 abut, an excessive load is not applied to the position adjusting protrusion 54 and the second tooth portion 59 by the play 60.

As shown in (3), since the second tooth portion 59 is moved to a predetermined position by the position adjusting projection 54, the first tooth portion 53 and the second tooth portion 59 are smoothly engaged.

(Second Embodiment) FIG. 2 is an exploded view of a part of a second embodiment of the gear mechanism according to the present invention. A shaft 63 is provided on the planetary gear arm 62, and a planetary gear 65 is fitted on the shaft 63. In order to loosely fit the planetary gear 65, the diameter of the through hole provided in the planetary gear 65 is
3 is larger than the diameter. 64 is a spring.

FIG. 3 shows a state where the center of the shaft 63 and the center of the spring 64 are displaced so that the planetary gear 65 is biased in the direction of the sun gear. Spring 6
4 is shown in a sectional view. Reference numeral 66 denotes a play portion.

The operation of the second embodiment of the gear mechanism according to the present invention will be described below. As shown in FIG.
And the top of the second tooth portion 72 provided on the planetary gear 65 abuts on the top of the position adjustment projection 70 provided on the planetary gear 65. Note that 7
Reference numeral 1 denotes a stopper, and 73 denotes a rotating shaft.

As shown in FIG. 5, since there is a play portion 66, the planet gear 65 escapes in the direction of arrow A. As a result, no excessive load is applied to the position adjusting protrusion 70 and the second tooth portion 72.

As shown in FIG. 6, when the sun gear 67 further rotates, the second tooth portion 72 of the planetary gear 65 is guided to a predetermined position, and the engagement between the first tooth portion 69 and the second tooth portion 72 is smooth. It is performed.

As shown in FIG. 7, since the spring is urged in the direction of arrow B by the spring, it is possible to stabilize the engagement between the first teeth 69 and the second teeth 72 while having the play 66. Can be.

Next, a facsimile apparatus provided with the present invention will be described. FIG. 8 is a configuration diagram showing a schematic configuration of a facsimile apparatus provided with a gear mechanism according to the present invention. FIG. 9 is a configuration diagram showing the configuration of the switching mechanism in FIG. In the drawings of the embodiments described below,
The part to which the copy function is added is omitted. However, it can be said that the switching mechanism according to the present invention is useful regardless of the presence or absence of the copy function. Referring to FIG. 8, facsimile apparatus 1 includes a reading unit 12 for reading transmission information, and a DC motor 2 serving as a power source for conveying recording paper.
3, a system gear 32 which is a main part of a switching mechanism, a roll-shaped recording paper 21, a roll-recording-paper transport roller 20 for transporting the roll-shaped recording paper 21, a sheet-shaped recording paper 2, and a sheet-shaped recording paper 2. A recording paper cassette 3 for accommodating the recording paper 2, a sheet paper transport roller 4 for transporting the sheet-like recording paper 2, a first idler gear 5a for transmitting power to the sheet paper transport roller 4, and a second idler gear 5a. Idle gear 5b
A transport path 33 for transporting the sheet-shaped recording paper 2 or the roll-shaped recording paper 21; and a recording unit 34 for recording an image on the recording paper.

At a position facing the reading surface of the reading unit 12, a document transport roller 14 for transporting the document 13 is provided. The original 13 on which the transmission information is described is transferred by the original transport roller 14 to the reading unit 1.
2 on the reading surface. Thus, the transmission information is read. Worm gear 2 for driving system gear 32 is provided on DC motor 23.
2 are installed. The worm gear 22 drives the system gear 32. The planet gear arm 25 is rotatably attached to the system gear 32. A planetary gear 7 for selectively transmitting the power transmitted to the system gear 32 to the roll recording paper transport roller 20 or the first idler gear 5a is provided on a rotating shaft provided at one end of the planetary gear arm 25. It is fitted.

A lock claw 26 for controlling the operation of the planetary gear arm 25 is further fitted into the system gear 32. The system gear 32 is further provided with a gear position detection sensor 31. The system gear 32 itself includes a worm wheel 27, a head release system drive pulley 28, a sun gear 29, and a gear position detecting cam 30. And, the system gear 32
Is provided with a lock claw drive groove 24 for driving the lock claw 26. The lock claw 26 is driven along the lock claw drive groove 24. That is, the lock claw drive groove 2 accompanying the rotation of the system gear 32
4 rotates the lock pawl 26 to the system gear 32.
Reciprocate in the diametrical direction.

The recording paper transport path 33 is provided for the rolled recording paper 2
The one conveyance path and the sheet-shaped recording paper 2 conveyance path are provided so as to merge at a predetermined position. In the transport path for the roll-shaped recording paper 21, a roll recording paper transport roller 20 is provided, and in the vicinity of the confluence of the transport path,
A roll recording paper sensor 19 is provided. Thus, it is possible to determine whether or not the roll recording paper 21 is near the confluence in the transport path 33. on the other hand,
The sheet-like recording paper conveying roller 4 is provided at a predetermined position on the sheet-like recording paper 2 and is provided with a planetary gear 7 via a first idler gear 5a and a second idler gear 5b.
Is connected to A sheet recording paper sensor 6 is provided at a predetermined position in the transport path of the sheet recording paper 2. A recording paper accumulation section 8, an A4 detection sensor 17, and a recording section 34 are provided in a portion after the confluence of the sheet recording paper conveyance path and the roll recording paper conveyance path.

The recording section 34 includes the print head 10, the head release cam 15, and the head release pulley 16. The head release pulley 16 is connected to a system gear 32
Are connected via a timing belt 9 to a head release system drive pulley 28. As a result, the head release pulley 16 rotates in conjunction with the rotation of the head release pulley 28 accompanying the rotation of the system gear 32.
Thereby, the head release cam 15 rotates, and the position of the print head 10 moves. The platen roller 11 is provided at a predetermined position of the recording unit 34 facing the print head 10. The recording paper on which recording has been performed by the print head 10 is conveyed by the platen roller 11.

The switching mechanism of the facsimile machine 1 will be described in more detail with reference to FIG. Referring to FIG. 9, sun gear 29 in system gear 32 transmits power from system gear 32 by meshing with planetary gear 7. A portion 2 having substantially the same diameter as the sun gear 29 and not transmitting power because it does not mesh with the planetary gear 7.
9a is provided. That is, the sun gear 29 also rotates with the rotation of the system gear 32, and the sun gear 29
The power is transmitted only when the planetary gear 7 meshes with the power.

The gear position detecting cam 30 has a recess 30a.
The initial position of the rotation of the system gear 32 can be detected by detecting the concave portion 30a with the gear position detection sensor 31. The lock claw 26 is fitted into the lock claw drive groove 24 and has a protrusion (not shown) on the system gear 32 side. The rotation of the planetary gear arm 25 is restricted by the projection. The lock claw 26 reciprocates in a direction approaching the system gear 32 or away from the system gear 32, as indicated by an arrow in FIG. For example, when the system gear 32 rotates counterclockwise, the planetary gear 7 meshes with the first idler gear 5a. Prevents the planetary gear arm 25 from rotating clockwise. That is, the locking claw 26 allows the planetary gear arm 25
Is fixed at a position where power can be transmitted to the first idler gear 5a.

As a result, power can be transmitted to the sheet recording paper transport roller 4, and the sheet recording paper 2 can be supplied to the recording section 34. The sheet recording paper transport roller 4 includes a sheet recording paper transport gear 4a. The sheet recording paper transport gear 4a includes a second idler gear 5b.
Is transmitted from the vehicle. Thereby, the sheet recording paper transport roller 4 rotates. On the other hand, the roll recording paper transport roller 20 is also coaxially provided with the roll recording paper transport gear 20.
a, and the roll recording paper transport gear 20a
Then, the power from the planetary gear 7 is transmitted. As a result, the roll recording paper transport roller 20 rotates, and the roll recording paper 21 is supplied to the recording unit 34. As described above, the recording head 10 in the recording unit 34
Head release drive pulley 28 in system gear 32
Is set to work together, in this case,
The rotation of the head release pulley 16 and the head release cam 15 causes the head release pulley 16 and the head release cam 15 to move in the direction indicated by the arrow in the figure. This makes it possible to reduce or eliminate the pressing of the print head 10 against the platen roller 11.

The operation of the facsimile machine 1 having the above configuration will be described with reference to FIGS. FIG. 10 shows a state (a) in which the roll-shaped recording paper 21 can be supplied, a state (c) in which the sheet-shaped recording paper 2 can be supplied, and a transition between the roll-shaped recording paper supply state and the sheet-shaped recording paper supply state. It is explanatory drawing which shows a state (neutral state) (b).

Referring to FIG. 10, the system gear 32 is rotated in the forward direction (leftward rotation direction) from the state (a) in which the roll-shaped recording paper 21 is conveyed to the neutral state (b). Thereafter, by further rotating the system gear 32 in the forward direction, the state shifts to the cut recording paper 2 transport state (c). When shifting from the sheet recording paper supply state (c) to the roll recording paper supply state (a), first, the sheet recording paper is discharged by the platen roller 11. Then, the state is shifted from the sheet-like recording paper supply state (c) to the neutral state (b). Thereafter, the system gear 32 is rotated in the reverse direction (rightward rotation) to shift from the neutral state (b) to the roll recording paper supply state (a).

The above switching operation is described with reference to FIGS.
6 will be described in more detail. FIG. 11 is an explanatory diagram showing the switching operation from the roll recording paper supply state (a) to the neutral state (b) step by step. FIG. 14 is a diagram showing a timing chart when the above switching operation is performed.

Referring to FIGS. 11 and 14, switching from the roll recording paper supply state to the neutral state can be performed by rotating system gear 32 once in the forward direction. First, as shown in FIG. 11A, the mode switching key is turned on, and the platen roller 1 is turned on.
1 is started to rotate in the forward direction (left rotation direction) at a rotation speed of, for example, about 400 pps. Thereby, a part of the roll-shaped recording paper 21 is deflected in the recording paper pool 8. FIG.
FIG. 17 shows the relationship between the planetary gear 7 and the sun gear 29 in the state of 1 (1). 7a is a second tooth portion, 29a
Denotes a first tooth portion, 49 denotes a play portion, and 50 denotes a position adjusting protrusion. Then, after rotating the platen roller 11 in the forward direction by a predetermined amount, as shown in FIG. 11 (2), the worm gear 22 is rotated in the reverse direction by energizing the DC motor 23 serving as a power source. Thereby, the system gear 32 rotates in the forward direction. At this time, the rotation of the system gear 32 causes the head release system driving pulley 2 to rotate.
8 rotates, and the head release cam 15 rotates in conjunction therewith. Thereby, the pressure of the print head 10 is reduced or set to zero. FIG. 18 shows the relationship between the planetary gear 7 and the sun gear 29 in the state of FIG. 11 (2).

The system gear 32 further rotates, and FIG.
As shown in FIG. 1 (3), the sun gear 29 is
Begins to engage with. Thereby, the planetary gear 7 rotates in the reverse direction, and the roll recording paper transport gear 20a (not shown) that meshes with the planetary gear 7 rotates in the reverse direction. Thereby, the roll recording paper transport roller 20 also rotates in the reverse direction, and the roll recording paper 21 in the transport path is pulled back. At this time, a force acts on the planetary gear arm 25 in the direction of left rotation, but the lock claw 26 is
Since it is located on the second side, the rotation of the planetary gear arm 25 is limited. As a result, the planetary gear 7 keeps meshing with the roll recording paper transport gear 20a. FIG. 11 (3)
FIG. 19 shows the relationship between the planetary gear 7 and the sun gear 29 in the state of FIG.

The system gear 32 continues to rotate in the forward direction, whereby the roll recording paper is gradually pulled back. Then, as shown in FIG. 11 (4), the A4 detection sensor 17 and the roll recording paper detection sensor 19 sequentially enter a paper-out state (OFF state). Here, the rotation of the platen roller 11 is stopped when the A4 detection sensor 17 is out of paper or when the rotation of the platen roller 11 has been completed by a predetermined amount. Eventually, as the system gear 32 rotates, the lock claw 26 is moved away from the system gear 32 by the lock claw drive groove 24 integrated with the system gear 32. Thereby, the left rotation of the planetary gear arm 25 becomes possible. At this time, the system gear 3
2, the diameter of the sun gear portion 29, the diameter of the roll recording paper transport roller 20, and the sun gear portion 29
By appropriately setting the speed reduction ratio up to, the leading end of the roll recording paper can be adjusted so as to be located between the roll recording paper detection sensor 19 and the roll recording paper transport roller 20. FIG. 20 shows the relationship between the planetary gear 7 and the sun gear 29 in the state of FIG. 11 (4).

When the planetary gear arm 25 can rotate leftward, the planetary gear arm 25 immediately rotates leftward,
As shown in FIG. 11 (5), the planetary gear 7 comes to a position where it meshes with the first idler gear 5a. However, the sun gear 29 in the system gear 32 has passed through the planetary gear 7, and the planetary gear 7 and the sun gear 29 are no longer meshing. Therefore, the power of the system gear 32 is not transmitted to the first idler gear 5a via the planetary gear 7. Therefore, the sheet recording paper transport roller 4 hardly rotates. FIG. 21 shows the relationship between the planetary gears and the sun gear 29 in the state of FIG. 11 (5).

The system gear 32 is further rotated, and FIG.
When just one rotation from the state of (1), FIG.
As shown in (2), the gear position detection sensor 31 detects a concave portion of the gear position detection cam 30. As a result, the gear position detection sensor 31 is turned on, and at this time, the DC
The energization of the motor 23 is stopped. Thus, the rotation of the system gear 32 stops. And the system gear 32
The rotation of the head release cam 15 linked to the print head 1 also stops, and the print head 1 returns to its original state shown in FIG.
Pressing to zero is restored. FIG. 22 shows the relationship between the planetary gear 7 and the sun gear 29 in the state of FIG. 11 (6).

As described above, it is possible to switch from the roll recording paper supply state to the neutral state by rotating the system gear 32 once in the forward direction.

Next, the switching operation from the neutral state (b) to the sheet recording paper supply state (c) will be described with reference to FIGS. FIG. 12 is a configuration diagram showing the switching operation from the neutral state (b) to the sheet recording paper supply state (c) step by step. FIG. 16 is a timing chart of the switching operation.

The sheet recording paper feeding operation is performed by rotating the system gear 32 once in the forward direction from the neutral state (b). First, the above neutral state (b)
Then, by rotating the DC motor 23 in the reverse direction, the system gear 32 is rotated in the forward direction. As a result, as shown in FIG.
The head release cam 15 rotates in conjunction with the rotation of. Thereby, the pressing of the print head 10 is reduced.

Thereafter, the system gear 32 further rotates, and the sun gear 29 meshes with the planetary gear 7.
As a result, the rotational torque of the system gear 32 is reduced by the planet gear 7, the first idler gear 5a and the second idler gear 5a.
The recording paper is transmitted to the sheet recording paper transport roller 4 via b. Thus, as shown in FIG. 12B, the sheet recording paper transport roller 4 starts rotating.

The rotation of the sheet recording paper transport roller 4 causes the recording paper cassette 3 to rotate as shown in FIG.
The sheet recording paper 2 stored therein is conveyed, and the sheet recording paper detection sensor 6 provided in the conveyance path detects whether or not the sheet recording paper 2 is in the conveyance path.

The system gear 32 further rotates in the forward direction to convey the sheet recording paper. Thus, as shown in FIG. 12D, the A4 detection sensor 17 provided downstream of the sheet recording paper detection sensor 6 in the recording paper transport path is turned on, that is, the recording paper is present. . At this time, as shown in FIG. 12D, the leading end of the sheet-shaped recording paper 2 is
And near the contact surface with the platen roller 11, and is slightly bent.

Accordingly, as shown in FIG.
By temporarily stopping the power supply to the C motor 23,
The rotation of the system gear 32 is temporarily stopped. Thereafter, as shown in FIG. 12 (5), the platen roller 11 is rotated in the reverse direction at a speed of, for example, about 400 pps for a predetermined time. Thereby, the leading edge of the recording paper reaches a predetermined position,
The bending of the recording paper is eliminated. On the other hand, the system gear 32
Is a platen roller 1 as shown in FIG.
1 again rotates in the opposite direction, and the sheet-like recording paper 2
Is carried. Then, the gear position detection sensor 31 detects the concave portion 30a of the gear position detection cam 30 that rotates together with the system gear 32 according to the rotation of the system gear 32. Thereby, the gear position detection sensor 3
1 is in the OFF state, and the DC motor 23
The power supply to is stopped. At this time, this system gear 3
The head release cam 15 linked to 2 also makes one rotation, and the pressure on the print head 10 is restored.

As described above, by making one rotation of the system gear 32 in the forward direction, it is possible to shift from the neutral state (b) to the sheet recording paper supply state (c).

Next, the switching operation from the neutral state (b) to the roll recording paper supply state (a) will be described with reference to FIGS.
5 will be described. FIG. 13 is a block diagram showing the switching operation from the neutral state (b) to the roll recording paper supply state (a) step by step. FIG. 15 is a timing chart of the switching operation.

The switching operation from the neutral state (b) to the roll recording paper supply state (a) is performed by rotating the system gear 32 in the reverse direction by one.
This is done by rotating. First, FIG.
As shown in (1), the system gear 32 is rotated in the reverse direction by rotating the DC motor 23 in the forward direction at a rotation speed of, for example, 400 pps. As a result, the head release cam 15 that rotates in conjunction with the system gear 32 rotates, and the pressing of the print head 10 is reduced. And
The lock claw 26 is moved in a direction away from the system gear 32 by the lock claw drive groove 24 provided integrally with the system gear 32. Thereby, the rotation of the planetary gear arm 25 fixed by the lock claw 26 becomes free.

When the system gear 32 is further rotated in the reverse direction from the above state, the sun gear 2 of the system gear 32 is rotated.
9 meshes with the planetary gear 7. At this time, since the planetary gear arm 25 is not restrained by the lock claw 26, the planetary gear arm 25 is rotated in the opposite direction by the force between the tooth surfaces of the sun gear 29 and the planetary gear 7. Thereby, FIG. 13 (2)
As shown in (1), the planetary gear 7 comes into mesh with a roll recording paper transport gear (not shown). Thereby, the rotation torque of the system gear 32 is transmitted to the roll recording paper transport roller 20 via the planetary gear 7 and the roll recording transport gear. As a result, the roll recording paper 21 is sent out to the platen roller 11 side.

As the system gear 32 further rotates, the leading end of the roll recording paper 21 passes through the roll recording paper detection sensor 19 as shown in FIG. Becomes). Thereafter, the system gear 32 further rotates, and FIG.
As shown in (2), the leading end of the roll recording paper 21 reaches the A4 detection sensor 17. Thereby, the A4 detection sensor 17
Is in the ON state, that is, the state with paper. After the system gear 32 further rotates by a certain amount, the platen roller 11 starts to rotate in the reverse direction.

When the system gear 32 further rotates from the above state, as shown in FIG. 13 (5), the sun gear 29 and the planetary gear 7 in the system gear 32 do not mesh with each other. That is, the roll recording paper is no longer transported by the roll recording paper transport roller 20. However, since the leading end of the roll recording paper has already been transported to reach the platen roller 11, the roll recording paper 21 is transported by the platen roller 11. Then, as shown in FIG. 15, the platen roller 11 stops after rotating by a certain amount.

The system gear 32 further rotates in the opposite direction, and as shown in FIG.
The gear position detection sensor 31 detects the concave portion 30a in the gear position detection cam 30 which rotates together with the gear position detection cam 30. That is, the initial position of the system gear 32 is detected. Accordingly, the energization of the DC motor 23 is stopped, and the rotation of the system gear 32 is stopped.
At this time, the head release cam 15 linked with the system gear 32 also makes one rotation, and the pressing of the print head 10 is restored.

Through the above operation, the supply of the roll recording paper or the sheet recording paper is selectively performed.

[0055]

According to the first aspect of the present invention, since the planetary gear is loosely fitted to the planetary gear arm, even if the top of the position adjusting projection and the top of the second tooth portion contact each other, the planetary gear can be used. Moves to the opposite side of the sun gear. For this reason, troubles such as wear and breakage of the position adjustment protrusion and the second tooth portion due to excessive load applied to the position adjustment protrusion and the second tooth portion can be prevented. In addition, it is possible to prevent generation of noise caused by releasing the contact between the top of the position adjusting protrusion and the top of the second tooth portion.

According to the second aspect of the present invention, in addition to the effect of the first aspect, the meshing between the first tooth portion and the second tooth portion can be further stabilized.

[Brief description of the drawings]

FIG. 1 is a front view for explaining the operation of a first embodiment of a gear mechanism according to the present invention.

FIG. 2 is an exploded view of a part of a second embodiment of the gear mechanism according to the present invention.

FIG. 3 is a sectional view of a part of a second embodiment of the gear mechanism according to the present invention;

FIG. 4 shows a first example of a second embodiment of the gear mechanism according to the present invention.
It is a front view for explaining operation.

FIG. 5 shows a second embodiment of the gear mechanism according to the present invention.
It is a front view for explaining operation.

FIG. 6 shows a third embodiment of the gear mechanism according to the present invention.
It is a front view for explaining operation.

FIG. 7 shows a fourth embodiment of the gear mechanism according to the present invention;
It is a front view for explaining operation.

FIG. 8 is a configuration diagram showing a schematic configuration of a facsimile apparatus provided with a gear mechanism according to the present invention.

9 is a configuration diagram showing a switching mechanism in the facsimile apparatus shown in FIG.

10 is an explanatory diagram showing a roll recording paper supply state (a), a neutral state (b), and a sheet recording paper supply state (c) of the facsimile apparatus shown in FIG.

FIG. 11 is an explanatory diagram illustrating a step-by-step switching operation from a roll recording paper supply state to a neutral state.

FIG. 12 is an explanatory diagram showing a step-by-step switching operation from a neutral state to a sheet recording paper supply state.

FIG. 13 is an explanatory diagram showing stepwise a switching operation from a neutral state to a roll recording paper supply state.

14 is a timing chart in the switching operation shown in FIG.

15 is a timing chart in the switching operation shown in FIG.

FIG. 16 is a timing chart in the switching operation shown in FIG.

FIG. 17 is a front view showing the relationship between the planetary gear 7 and the sun gear 29 in the state of FIG. 11 (1).

FIG. 18 is a front view showing the relationship between the planetary gear 7 and the sun gear 29 in the state of FIG. 11 (2).

FIG. 19 is a front view showing the relationship between the planetary gear 7 and the sun gear 29 in the state of FIG. 11 (3).

FIG. 20 is a front view showing the relationship between the planetary gear 7 and the sun gear 29 in the state of FIG. 11 (4).

FIG. 21 is a front view showing the relationship between the planetary gear 7 and the sun gear 29 in the state of FIG. 11 (5).

FIG. 22 is a front view showing the relationship between the planetary gear 7 and the sun gear 29 in the state of FIG. 11 (6).

FIG. 23 is a front view for explaining a first operation of the conventional gear mechanism.

FIG. 24 is a front view for explaining a second operation of the conventional gear mechanism.

[Explanation of symbols]

 Reference Signs List 51 gear mechanism 52 sun gear 53 first tooth portion 54 position adjusting projection 55 planetary gear arm 56 rotation shaft 58 planetary gear 59 second tooth portion 60 backlash portion 61 rotation shaft

Claims (2)

(57) [Claims] A sun gear having a first tooth portion formed only on a part of an outer periphery thereof; a planetary gear arm provided coaxially with the sun gear; and a planetary gear arm located around the sun gear, A planetary gear, which is rotatably held and has a second tooth portion meshing with the first tooth portion formed on an outer periphery thereof; and the sun gear includes the first tooth portion and the second tooth portion. In a gear mechanism provided with a position adjusting projection which abuts on the second tooth portion before meshing and adjusts the position of the second tooth portion, it is preferable that the planetary gear is loosely fitted to the planetary gear arm. Characteristic gear mechanism. 2. The gear mechanism according to claim 1, wherein said planetary gear arm is provided with biasing means for biasing said planetary gear toward said sun gear.