JP2783732B2 - Platen position detector for platen drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a platen position detecting device for a platen driving device for reciprocating a platen.

[0002]

2. Description of the Related Art In a copying machine in which an image is formed by moving a platen, when a document on the platen is scanned by an optical system, the platen first moves from a standby position to a scanning start position in a return direction. Then, after moving in the feed direction to the scanning end position and scanning the original, the original is moved from the scanning end position to the original standby position in the return direction.

A conventional platen driving device 81 for moving the platen as described above is provided below a platen 82 as shown in FIG. 20, and has a structure as shown in FIG. That is, when the document table 82 is moved from the scanning start position in the feed (F) direction, the feed solenoid 83 is turned on, whereby the latch 84 is engaged with the clutch brake 86 of the feed spring clutch 85, The feed spring clutch 85 is brought into a connected state. As a result, the driving force input to the input gear 87 is transmitted to the output gear 88, and further transmitted to the platen drive gear 89, so that the platen 82 provided with a rack that meshes with the platen drive gear 89 feeds (F) ) Direction.

Thereafter, when the document table 82 reaches the scanning end position, this state is detected by the detection switch 90 shown in FIG. 20, and the feed solenoid 83 is turned off and the return solenoid 81 is turned on. As a result, the latch 82 is engaged with the clutch brake 83 of the return spring clutch 87, and the return spring clutch 87 is engaged. Therefore, the driving force input to the input gear 87 is transmitted to the platen drive gear 89 via the gear 84, the input gear 85, the output gear 86, and the output gear 88, and the platen 82 is moved in the return (R) direction. It moves to the standby position.

However, in the above structure, the feed spring clutch 8 is used to reciprocate the document table 82.
5. A device such as a return spring clutch 87, a feed solenoid 83, and a return solenoid 81 is required. There is a problem that the ratio of the occupied cost is increased and the cost of the apparatus is increased.

In order to solve the above problems, the applicant has
A document table driving device using an endless gear has been previously proposed (see Japanese Patent Application No. 3-118860). That is, as shown in FIG. 10, which is an explanatory view of the present invention, a platen driving device using an endless gear has two upper rack portions 5 and lower rack portions 6 provided in parallel with their tooth surfaces facing each other. And an annular ring composed of two return-side (R-side) semi-circle internal gears 7a and a feed-side (F-side) semi-circle internal gear 7b that connect the respective ends of the racks 5 and 6 respectively. An endless gear 8 is provided. The endless gear 8 is connected to the document table 2 and is provided so as to be linearly movable integrally with the document table 2. A sun gear 9 to which the driving force of the main motor is input is fixedly provided at an intermediate portion between the rack portions 5 and 6 inside the ring of the endless gear 8.

Further, between the sun gear 9 and the endless gear 8, a large-diameter planetary gear 10 b and a small-diameter planetary gear 10 c meshing with the two gears 9, 8, and a rotation about the input shaft 9 a of the sun gear 9. A connecting plate 11 is provided so as to be capable of being connected and supporting a gear shaft 10a of the large-diameter planetary gear 10b and the small-diameter planetary gear 10c.

When the driving force from the main motor is transmitted to the input shaft 9a, the sun gear 9 rotates in the direction of arrow A, and accordingly, the small-diameter planetary gear meshing with the upper rack portion 5. 10c rotates in the direction of arrow B to move the endless gear 8 in the feed (F) direction. Small diameter planetary gear 1
0c is a semicircular gear 7 on the return side of the endless gear 8
a, the endless gear 8 stops horizontal movement, the meshing between the small-diameter planetary gear 10c and the upper rack 5 is released, and then the large-diameter planetary gear 10b and the return-side semicircle internal gear 7a Mesh. When the connecting plate 11 starts to rotate counterclockwise about the input shaft 9a, the large-diameter planetary gear 10b revolves counterclockwise while meshing with the return-side semicircle internal gear 7a. Then, it rotates to the end point of the return side semicircle internal gear 7a. When reaching this position, the large-diameter planetary gear 10b is moved to the lower rack portion 6 of the endless gear 8.
The endless gear 8 moves in the return (R) direction, contrary to the above, and at this time, the document table 2 also horizontally moves in the return (R) direction. In this way, the rotation of the sun gear 9 in a certain direction allows the endless gear 8,
That is, the document table 2 repeats the reciprocating movement to return and feed. Therefore, by employing an endless gear for the platen driving device, the structure of the platen driving device is simplified, and the size can be reduced.

[0009]

In the above-mentioned document table driving device, the large-diameter planetary gear 10b has a semicircular internal gear 7a in the endless gear 8 due to a failure such as a jam.
-The motor may stop when it meshes with 7b. At this time, the main motor driving the platen driving device is immediately stopped by the failure detecting means of the copying machine. Further, in this state, the main power supply of the copying machine main body 1 is turned off.
F.

However, in the above-mentioned conventional platen driving device, the semicircular internal gear 7a of the endless gear 8 is used.
7b, i.e. outside α ₁ -α ₂ and α
When from _{3-.alpha. 4} large径遊star gear 10b to the outside of the position is stopped, the structure has a problem that it is impossible to move the endless gear 8 manually.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a document table driving device capable of detecting that a planetary gear has stopped at a position of a semicircular internal gear portion of an endless gear. To provide a platen position detecting device.

[0012]

According to a first aspect of the present invention, there is provided a platen position detecting device for a platen driving device according to the first aspect of the present invention. An annular endless gear, which is integrally connected to the document table and is provided so as to be reciprocally movable, comprising: The endless gear is provided at a fixed position at an intermediate portion between the two rack portions, and a sun gear to which the driving force of the motor is input, and between the sun gear and the endless gear, can mesh with the two gears and revolve. And a connecting plate rotatably connected to the rotation shaft of the sun gear, supporting the gear shaft of the planetary gear, and rotating along the endless gear. Document platen position A substantially circular cam that rotates integrally with the connection plate is provided at the center of rotation of the connection plate, and a start for detecting the start position of the endless gear is provided on the outer periphery of the cam. In order to detect the diameter portion and the position of the semicircular internal gear portion, two semicircular internal gear diameter portions formed so that the radius of the cam is different from the start radial portion, and the rack portion are detected. Therefore, while two rack diameter portions having different radii are formed, an end portion abuts on the outer periphery of the cam, and a contact member having a fulcrum serving as a rotation center is provided at substantially the center, and the abutment member is provided. A first contact and a second contact are provided near the other end of the member on the side opposite to the cam, and the first contact and the second contact are such that the end of the contact member has a cam diameter of the cam. When abutting on the first portion, the other end of the abutting member is connected to the first contact and the second contact. When the end of the abutment member abuts on the semi-circular in-gear gear diameter portion of the cam without contacting the point, the other end of the abutment member contacts only the first contact, and the end of the abutment member. When the portion comes into contact with the start diameter portion of the cam, the other end of the contact member is provided at a position where it contacts only the second contact.

According to a second aspect of the present invention, there is provided a platen position detecting device for a platen driving device according to the first aspect of the present invention. If the other end of the contact member is in contact with the first contact when the main power supply is turned on, the motor is rotated until the other end of the contact member does not contact the first contact. A motor control means is provided.

According to a third aspect of the present invention, there is provided an original platen position detecting device for an original platen driving device, in order to solve the above-mentioned problems, two rack portions provided in parallel with their tooth surfaces facing each other and both of them. An annular endless gear which is integrally connected to a document table and is provided so as to be capable of reciprocating movement; and two racks in the endless gear. A sun gear, which is provided at a fixed position at an intermediate portion between the parts and receives the driving force of the motor, and a planetary gear provided between the sun gear and the endless gear so as to revolve by meshing with both gears. And a connection plate rotatably connected to the rotation shaft of the sun gear and supporting the gear shaft of the planetary gear, and having a connection plate that rotates along the endless gear. Device A substantially circular cam that rotates integrally with the connecting plate is provided at the center of rotation of the connecting plate, and two semicircular cams for detecting the position of the semicircular internal gear portion are provided on the outer periphery of the cam. Two rack diameter parts having different radii from the semicircle gear tooth part to detect the rack part and the rack part for detecting the start position provided on the rack part of the endless gear. A start diameter portion having a different radius from the diameter portion is formed, and an end portion abuts on the outer periphery of the cam, and a contact member having a fulcrum serving as a center of rotation is provided at substantially the center, and the contact member is provided. In the vicinity of the other end opposite to the cam, a contact is provided, and the other end of the contact member is in contact with the contact only when the end of the contact member comes into contact with the semicircular internal gear diameter of the cam. It is provided at the position where it comes into contact with ON · O in time
An output determining means for determining whether or not the FF has been repeated is provided.

[0015]

According to the first aspect of the present invention, since a substantially circular cam which rotates integrally with the connecting plate is provided at the center of rotation of the connecting plate, the cam rotates as the planetary gear revolves. Further, when the end of the contact member abuts against the rack radial portion of the cam, the other end of the contact member does not contact the first contact and the second contact, and the end of the contact member is connected to the cam rack. When abutting against the semi-circular internal gear radial portion having a different radius from the radial portion, the other end of the abutment member contacts only the first contact, and the end of the abutment member has a different start radius of the cam. When contacting the radial portion, the other end of the contact member contacts only the second contact. This makes it possible to detect that the planetary gear has stopped at the position of the semicircular internal gear portion of the endless gear.

According to the second aspect of the present invention, when the main power supply of the apparatus is turned on, the other end of the contact member is set to the first position.
When the contact is in contact, that is, when the planetary gear is located in the semicircular internal gear portion of the endless gear, the motor control means causes the other end of the contact member to contact the first contact. Since the motor is rotated until it no longer contacts, the planetary gear can be moved to the rack of the endless gear. As a result, the original table can be manually moved horizontally and returned to the start position.

According to the third aspect of the present invention, the other end of the contact member contacts the contact point only when the end of the contact member contacts the semi-circular internal gear diameter of the cam. This makes it possible to detect whether or not the planetary gear is located in the semicircular internal gear.

Further, when the planetary gear is located at the semicircular internal gear portion, the end of the contact member abuts on the semicircular internal gear diameter portion of the cam, and the other end of the contact member has the other end portion. The contact comes into contact with the contact and turns on. Further, when the planetary gear is located in the rack portion of the endless gear, the end of the contact member contacts the rack diameter portion of the cam, and since the other end of the contact member does not contact the contact, the contact is turned off. Become. Furthermore, when the planetary gear revolves and moves to the start position of the endless gear, the end of the contact member contacts the start diameter portion of the cam, and the other end of the contact member contacts the contact. The contact turns on. Further, when the planetary gear revolves and moves on the rack portion of the endless gear, the end of the contact member contacts the rack diameter portion of the cam, and the other end of the contact member does not contact the contact. The contact turns off. When the planetary gear further revolves and moves through the semicircular internal gear portion of the endless gear and the rack portion, the contacts are turned ON and OFF in order.

By the way, when the planetary gear moves near the start position of the endless gear, that is, when the planetary gear passes through the semicircular internal gear portion, the rack portion, the start position and the rack portion of the endless gear. The ON / OFF of the contacts is performed within a short time.

At this time, the output judging means turns ON / OFF within a predetermined time based on the ON signal output from the contact.
It is determined whether or not the above has been repeated. Therefore,
By setting the predetermined time in advance, it is possible to detect that the planetary gear is at the start position of the endless gear.

As a result, due to the difference in the output waveform of the contact,
It is possible to detect at which part of the endless gear the planetary gear is located.

Further, since only one contact is used, the cost can be reduced and the device can be prevented from becoming complicated.

[0023]

【Example】

Embodiment 1 FIGS. 1 to 1 show an embodiment of the present invention.
1 will be described below. The platen driving device of the present embodiment is provided in, for example, a copying machine.
As shown in FIG. 9, on the upper part of the substantially rectangular parallelepiped copying machine body 1,
A substantially rectangular plate-shaped document table 2 which is attached so as to be able to reciprocate.
Is installed. The platen 2 has a transparent member such as a glass plate at the center thereof, and the platen 2 is driven by a platen driving device 3 described later.

An optical system 20 comprising an irradiation lamp 15, a rod lens array 24, and the like is provided above the copying machine main body 1. Below the optical system 20, a drum-shaped photosensitive member 13 is provided. Are arranged. This photoconductor 13
Is provided so as to be rotatable, and is exposed by the reflected light of the light radiated from the irradiation lamp 15 toward the document 25, and the residual static electricity is eliminated by the direct light from the irradiation lamp 15. It has become.

Around the photosensitive member 13, a main charger 14 for charging the photosensitive member 13 is provided in contact with the photosensitive member 13, and a rotatable stirring roller 28 is provided.
A developing device 30 internally provided with a toner conveying roller 27, a toner carrier 29, and the like, and developing, with toner, an electrostatic latent image formed on the photoconductor 13 by an exposure operation of the optical system 20;
A transfer roller 12 for transferring a toner image formed by a developing operation of the developing device 30 onto transfer paper;
The toner remaining on the surface of the toner collecting portion 18 is collected.
A cleaning device 17 and the like to be accommodated in the printer are provided.

A transport section 32 is provided on the supply side (right side in the figure) of the photoconductor 13, and a paper supply section 33 is provided on the supply side. This paper feed unit 33
A manual feed tray 34 for accommodating transfer paper, a paper feed roller 35 for taking out the transfer paper one by one from the manual feed tray 34, and a paper feed solenoid 4 for controlling rotation of the paper feed roller 35, which will be described later.
The transfer paper is fed to the transport unit 32 by operating the paper feed solenoid 44 for a predetermined time based on a signal from a copy switch (not shown). It should be noted that a paper feed cassette may be mounted so that automatic paper feeding is possible.

On the other hand, the conveyance section 32 includes a paper input sensor 36 which is turned off when the transfer paper is detected, a registration roller 16 for temporarily stopping the transfer paper, and a registration roller solenoid 45 for controlling the rotation of the registration roller 16 which will be described later. The transfer paper supplied from the paper supply unit 33 is
The sheet is conveyed between the transfer roller 12 and the photoconductor 13 at a predetermined timing.

Also, on the transport side (left side in the figure) of the photosensitive member 13, jam sensors 38 and 39 for detecting the position of the jammed paper when a jam occurs, and a fixing device for fixing the toner image on the transfer paper. 19 is provided. Further, in the transport direction of the fixing device 19, the transfer paper is
9, a paper discharge sensor 37 for detecting that the paper has reached a paper discharge unit (not shown). Note that the paper discharge sensor 37 outputs an OFF signal at the time of detection.

In the copying operation, the document table 2 on which the document 25 is placed is positioned such that the end in the return direction (R) substantially coincides with the end of the copier body 1, that is, the standby position P _1. from, first, moved to the scanning start position P ₂ of the return direction (R), then, for document scanning by the optical system, it moved to the scanning end position P ₃ in the feed direction (F), then the original standby and moves to the position P _1. Scanning end position original table 2 from the scan start position P ₂ P
_While moving to ₃ , the original 25 is scanned by the optical system. That is, a document 25 placed on a transparent member of the document table 2 is irradiated by the irradiation lamp 15, and its reflected light is exposed to a rotatable photosensitive member 13 via a rod lens array 24. You. Then, in a state where the surface of the photoconductor 13 is uniformly charged by the main charger 14 disposed opposite to and close to the photoconductor 13, the reflected light from the original 25 is exposed, and 1
3, an electrostatic latent image is formed.

The electrostatic latent image is developed by the toner supplied from the developing device 30 to form a toner image corresponding to the original 25 on the photoconductor 13. Next, the transfer paper is supplied to the photoconductor 13 from the manual paper feed unit 34 via the transport roller 35 and the registration roller 16, and the toner image is transferred by the transfer roller 12 which is disposed in close proximity to the photoconductor 13. The image is transferred to paper, and the transfer paper is conveyed to the fixing device 19.

After the transfer of the toner image onto the transfer paper, the residual toner adhered to the transfer roller 12 is moved onto the photosensitive member 13 by applying a voltage having a polarity opposite to that of the toner to the transfer roller 12. The toner moved by the transfer roller 12 is removed by the cleaning device 17 together with the toner remaining on the photoconductor 13, and is collected in the toner storage unit 18. Further, the surface of the photoreceptor 13 after the transfer is the irradiation lamp 1
The charge is uniformly removed by the direct light of No. 5 and the apparatus enters a standby state.
On the other hand, when the transfer paper is conveyed to the fixing device 19, the toner image on the transfer paper is heated and pressed by the fixing device 19 to be fixed on the transfer paper, and then the transfer paper is carried out. Note that the above-described document scanning is started based on an output from a table sensor 22 of a position detection device provided in the document table driving device 3 described later.

The movement of the document table 2 during such a copying operation is performed by the document table driving device 3 shown in FIG. The platen driving device 3 has a main support 4 on which an endless gear 8 is provided. The main support 4 has a vertical wall shape, is connected to the platen 2 in a hanging manner, and It moves along with the document table 2 along the side surface of the main body 1.
An oval concave portion is formed at the center of the main support 4, and an annular endless gear 8 having internal teeth is formed in the concave portion.
Is provided.

The above-mentioned endless gear 8 connects the upper rack portion 5 and the lower rack portion 6 provided in parallel with the tooth surfaces facing each other, and the respective end portions of these two rack portions 5 and 6, respectively.
It is composed of a return side semicircle internal gear portion 7a having internal teeth arranged in a semicircular shape and a feed side semicircle internal gear portion 7b. The upper rack portion 5 has a gear pitch formed to be smaller than that of the lower rack portion 6 and has a gear width substantially half, and is arranged on the copying machine main body side. A step is provided inward.

Inside the endless gear 8, a sun gear 9 is fixedly provided at an intermediate portion between the upper and lower racks 5 and 6, and between the sun gear 9 and the endless gear 8, A planetary gear 10 meshing with both is provided. The planetary gear 10 includes a small-diameter planetary gear 10c and a large-diameter planetary gear 10b, which are two large and small gears. The small-diameter planetary gear 10c has a smaller diameter and a smaller number of teeth than the large-diameter planetary gear 10b. And the large-diameter planetary gear 10
b is arranged on the copying machine main body side and meshes with the upper rack portion 5. The large-diameter planetary gear 10b is adhered to the small-diameter planetary gear 10c so as to rotate integrally with the small-diameter planetary gear 10c.
a and the feed side semicircle internal gear 7b.

The main support 4 has an endless gear 8
Move, the input shaft 9a which is the rotation shaft of the sun gear 9
Are formed in parallel with the upper and lower rack portions 5 and 6. A driving force from a main motor 41 described later is transmitted to the input shaft 9a.

A gear shaft 10a serving as a gear shaft of the large-diameter planetary gear 10b and the small-diameter planetary gear 10c is rotatably connected near the center of the connecting plate 11. This connecting plate 1
Reference numeral 1 denotes an input shaft 9a of a sun gear 9 rotatably connected near one end thereof, and a slide member (not shown) connected to the outside of the connection plate 11 serves to protect a main support 4 (not shown). By sliding a slide guide groove (not shown) provided on the back side of the cover, the connecting plate 11 rotates along the endless gear 8.

The platen driving device 3 is provided with a platen position detecting device as platen position detecting means for detecting the position of the platen 2. Platen position detector 50
As shown in FIG. 10, a cam 51 and an actuator 52 as an abutting member abutting on the outer periphery of the cam 51 are provided.
And a first sensor 53 as a first contact provided near an end of the actuator 52 opposite to the cam 51.
And a second sensor 54 as a second contact.

The cam 51 is formed substantially in the shape of a disk, is mounted concentrically with the center of rotation of the connecting plate 11, and rotates integrally with the connecting plate 11. On the outer periphery of the cam 51, a start diameter portion 51a formed of a convex portion for detecting the start position α ₃ of the endless gear 8 and a cam 51 for detecting the positions of the semicircular internal gear portions 7a and 7b are provided. In order to detect two semi-circular in-tooth gear diameter portions 51b and 51d having protrusions slightly smaller than the protrusions of the start diameter portion 51a so that the radii are different from the start diameter portion 51a, and to detect the rack portions 5 and 6, Two rack diameter portions 51c and 51e that are concave portions are formed so as to have different radii.

The actuator 52 is formed in a U-shape and has a fulcrum 55 serving as a center of rotation substantially at the center, and the fulcrum 55 is supported by a protective cover (not shown).

The first sensor 53 and the second sensor 54
Is that the end of the actuator 52 is
Alternatively, the control device 3
1 is output.

The first sensor 53 and the second sensor 54 are arranged such that the end 52a of the actuator 52 is
The other end 52b does not contact the first sensor 53 and the second sensor 54 when contacting the first rack diameter portions 51c and 51e.
The other end 52b contacts only the first sensor 53 when contacting 51d, and the other end 52b contacts only the second sensor 54 when the end 52a of the actuator 52 contacts the start diameter portion 51a of the cam 51. It is provided in the position where it does.

The platen driving device 3 is provided with a copier main body 1.
And is controlled by the control device 31 shown in FIG. The control device 31 includes a main power switch 40, a print switch 23, a paper input sensor 36, a paper discharge sensor 37,
Output signals such as ON / OFF from the table sensor 22 and the like are input. Based on these output signals, the control device 31 transmits a ready lamp 41 and a copy lamp provided on a display unit of the copying machine main body 1 (not shown). A signal for turning ON / OFF a reference numeral 42, a main motor 43, a sheet feeding solenoid 44, a registration roller solenoid 45, a high voltage unit 46 for supplying a high voltage to the main charger 14 and the transfer roller 12, and the like are output.

Further, the control device 31 has a memory 47, and the main power switch 40 of the copying machine body 1 is turned off.
The document table 2 is positioned on the end side, that is, the planetary gear 10 meshes with the semicircle internal gears 7a and 7b based on the detection result of the table sensor 22. Is stored in the memory 47. Further, the control device 31 has a function as a motor control means. When the first sensor 53 is turned on when the main power switch 40 of the copying machine main body 1 is turned on, the planetary gear 10 is turned halfway. The main motor 43 is turned on until it passes through the inner gear portions 7a and 7b.

Next, the operation of the platen driving device 3 will be described with reference to FIG.

First, the driving force is input to the input shaft 9a of the sun gear 9, and the sun gear 9 rotates, for example, clockwise, that is, in the direction of arrow A. At this time, the planetary gear 10 maintains the mesh with the sun gear 9 and the upper rack portion 5 by the connecting plate 11 that rotatably supports the rotation shaft 10a of the sun gear 9 and the planetary gear 10, and rotates in the counterclockwise direction. Rotate in a certain B direction,
As a result, the endless gear 8 moves in the feed direction (F).
Move straight to. In addition, the endless gear 8
Is moved linearly in the feed direction (F).

Thereafter, when the sun gear 9 is further driven, the planetary gear 10 reaches the upper end of the return-side semicircle internal gear 7a, and the small-diameter gear 10c of the planetary gear 10 and the upper end of the endless gear 8 The meshing with the rack portion 5 is released, and the large-diameter planetary gear 10b of the planetary gear 10 meshes with the return-side semicircle-internal gear portion 7a. After rotating about 180 around the lower gear 9 and reaching the lower end of the return side semicircular internal gear 7a, the positional relationship between the sun gear 9 and the planetary gear 10 in the endless gear 8 is reversed upside down.

Subsequently, when the large-diameter planetary gear 10b meshes with the lower rack portion 6 and the sun gear 9 is further driven, the original table 2 and the endless gear 8 return together with the original table 2 in the opposite direction. Move in the R) direction.

As described above, as long as the sun gear 9 is rotating, the document table 2 alternately repeats the movement in the return direction and the feed direction. Note that the planetary gear 10 rotates only clockwise. Since the small-diameter planetary gear 10c has fewer teeth than the large-diameter planetary gear 10b, and the upper rack 5 has a smaller pitch than the lower rack 6, the document table 2 moves in the return (R) direction. Is higher than the moving speed in the feed (F) direction.

Further, in this copying machine, the main motor 43
In order to control the operation of the document table 2 only by turning ON / OFF, the transfer paper on which the document image has been transferred is fixed until the document table 2 returns to the standby position P1 in _one copy operation. The paper passes through the apparatus 19 and is discharged from the copying machine body 1.

Next, the operation of the platen position detecting device 50 for detecting the position of the platen 2 will be described.

As shown in FIG. 1, when the large-diameter planetary gear 10 b contacts the lower rack 6, the end 52 a of the actuator 52 contacts the rack diameter 51 c of the cam 51. It has become. At this time, the other end 52b of the actuator 52 is connected to the first sensor 5
Since neither the third sensor nor the second sensor 54 comes into contact, both the first sensor 53 and the second sensor 54 are turned off.

Next, as shown in FIG. 2, when the large-diameter planetary gear 10b comes into contact with the feed-side semicircle internal gear 7b, the end 52a of the actuator 52 is connected to the semicircular internal gear diameter of the cam 51. 51b, the actuator 52 pivots about the fulcrum 55, and the other end 52b contacts the first sensor 53, thereby causing the first sensor 5 to rotate.
3 turns ON. Thereafter, when the large-diameter planetary gear 10b further revolves, as shown in FIG. 3, the meshing between the large-diameter planetary gear 10b and the feed-side semicircle internal gear portion 7b is released. 10c is now meshed with the upper rack unit 5, finally, the small-diameter planetary gears 10c reaches the start position alpha _3. At this time, the actuator 52
End portion 52a abuts on the start diameter portion 51a of the cam 51, and the projection of the start diameter portion 51a is high, so that the actuator 52 further rotates and the other end portion 52b moves to the second position.
The second sensor 54 is turned ON by contact with the sensor 54.

As shown in FIG. 4, when the small-diameter planetary gear 10c further revolves and moves on the upper rack 5 of the endless gear 8, the end 5 of the actuator 52 is moved.
2a comes into contact with the rack diameter portion 51e of the cam 51,
The other end 52b does not contact either the first sensor 53 or the second sensor 54, and the first sensor 53 and the second sensor 54
Are both OFF. Thereafter, as shown in FIG. 5, this state is maintained until the small diameter planetary gear 10c further revolves and reaches the end of the upper rack portion 5.

Next, as shown in FIG. 6, the meshing between the small-diameter planetary gear 10c and the upper rack 5 is released, and the large-diameter planetary gear 10b meshes with the return-side semicircle internal gear 7a. . At this time, the end 52a of the actuator 52
Abuts on the semi-circular internal gear diameter portion 51d of the cam 51, and the other end portion 52b contacts the first sensor 53, whereby the first sensor 53 is turned ON.

Next, as shown in FIG. 7, when the large-diameter planetary gear 10b meshes with the lower rack 6, both the first sensor 53 and the second sensor 54 are turned off, as in FIG.

As a result, when the first sensor 53 is ON,
It is possible to detect that the large-diameter planetary gear 10b meshes with the return-side semicircle internal gear 7b or the feed-side semicircle internal gear 7b.

In the document table driving device 3 of this embodiment, when the main power supply of the copying machine main body is turned on, the large-diameter planetary gear 10b is rotated by the return-side semicircle internal gear 7a or the feed-side semicircle internal gear. When the gear is engaged with the gear portion 7b, the original platen 2 cannot be moved manually in this state.
Here, the original platen position detecting device 50 of this embodiment is provided with the control device 31 as a motor control means, and the main motor 43 is controlled by the control device 31.
Is operated to revolve the large-diameter planetary gear 10b until the meshing with the return side semicircle internal gear portion 7a or the feed side semicircle internal gear portion 7b is released.

That is, as shown in the flowchart of FIG. 8, when the main power of the copying machine is turned on (S1), it is determined whether or not the first sensor 53 is turned on (S2). S
If the first sensor 53 is not ON in Step 2, a copy switch (not shown) is turned ON (S3), whereby the main motor 43 is turned ON (S4). Next, the second sensor 5
4 is determined whether is ON (S5), if the second sensor 54 is ON, since the document platen 2 is in the start position alpha _3, the copying operation starts the double process described above with the start (S6).

On the other hand, if the first sensor 53 is ON in S2, the large-diameter planetary gear 10b
a or the position of the feed-side semicircle internal gear 7b, so that the control device 31 turns on the main motor 47 at this time (S7). Thereafter, it is determined whether or not the first sensor 53 is ON (S8), and S8 is repeated until the first sensor 53 is turned OFF. Next, when the engagement between the large-diameter planetary gear 10b and the return-side semicircle internal gear 7a or the feed-side semicircle internal gear 7b is released, the first sensor 53 is not turned ON. The motor 43 is turned off (S9), and the process proceeds to S3.

As described above, the platen driving device 3 of the present embodiment
In the platen position detecting device 50, a substantially circular cam 51 that rotates integrally with the connecting plate 11 is provided at the center of rotation of the connecting plate 11, so that the cam 51 includes a large-diameter planetary gear 10b and a small-diameter planetary gear 10c. It rotates with the revolution of. Also, the end 52 a of the actuator 52 is connected to the rack diameter portion 51 of the cam 51.
When the actuator 52 abuts against the c. 51e, the other end 52b of the actuator 52 does not contact either the first sensor 53 or the second sensor 54, and the end 52a of the actuator 52 is in contact with the rack diameter portions 51c and 51e of the cam 51. The other end 52b of the actuator 52 contacts only the first sensor 53 when the abutment is made on the semi-circular internal gear diameter portions 51b and 51d having different radii, and the end 52a of the actuator 52
In contact with the start diameter portion 51a having a further different radius, the other end portion 52b of the actuator 52 contacts only the second sensor 54, whereby the large-diameter planetary gear 10b causes the return-side semicircle of the endless gear 8 to move. The stop at the position of the internal gear portion 7a or the feed-side semicircular internal gear portion 7b can be detected.

Furthermore, by forming the shape of the cam 51 in three stages, the position of the planetary gears 10b and 10c is determined by using one actuator 52 and two sensors. Can be detected.

The original platen position detecting device 50 of this embodiment
When the main power supply of the copier is turned on, the other end 52b of the actuator 52 is in contact with the first sensor 53, that is, the large-diameter planetary gear 10b When located at the internal gear 7a or the feed-side semicircular internal gear 7b, the control means 31 as the motor control means stops the other end 52b of the actuator 52 from contacting the first sensor 53. Since the main motor 43 is rotated until this time, the large-diameter planetary gear 10 b can be moved to the upper rack 5 or the lower rack 6 of the endless gear 8. As a result, it is possible to return to the start position alpha ₃ by horizontally moving the platen 2 manually. Also, this allows the main power supply to be turned off once.
If N is set, the document table 2 is always in a reciprocating state in which the document table can be manually moved, and the jam processing can be easily performed.

The platen position detecting device 50 of this embodiment is
In the above, the shape of the cam 51 is such that the start radius 51a has the largest radius, and then the semi-circular internal gear radius 51b.
The radius of the first sensor 53 and the second sensor 54 is reduced by decreasing the radius in the order of 51d and the rack diameter portions 51c and 51e.
Is connected to the other end 5 of the actuator 52 as shown in FIG.
It is arranged on the left side of 2b. However, the shape of the cam 51 is not limited to this.
Has the smallest radius, and then the semi-circular internal gear portion 51b
The first sensor 53 and the second sensor 54 can be arranged on the right side of the other end 52b of the actuator 52 while increasing the radius in the order of 51d and the rack diameter portions 51c and 51e.

Embodiment 2 Another embodiment of the present invention is shown in FIG.
19 will be described below. For the sake of convenience, members having the same functions as those shown in the drawings of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 12, the original platen position detecting device 60 of the present embodiment is different from the original platen position detecting device 50 of the first embodiment.
However, the shape of the cam and the number of sensors are different.

That is, two semicircles for detecting the positions of the return-side semicircle internal gear 7a and the feed-side semicircle internal gear 7b are provided on the outer periphery of the cam 61 of the document table position detecting device 60. The internal gear diameter portions 61a and 61c and the semicircular internal gear diameter portions 61a and 61c for detecting the upper rack portion 5 and the lower rack portion 6 are formed as concave portions so as to have different radii. 61d and 61e, and a start position α ₃ provided on the upper rack portion 5 of the endless gear 8.
And a start diameter portion 61f formed as a projection so as to have a different radius from the rack diameter portions 61b, 61d, and 61e.

An end 52a of the actuator 52 as a contact member abuts on the outer periphery of the cam 60, and one sensor 63 as a contact is provided near the other end 52b of the actuator 52. ing.

Original platen position detecting device 6 having the above configuration
The operation of 0 will be described.

First, as shown in FIG. 12, when the large-diameter planetary gear 10b comes into contact with the lower rack portion 6, the end portion 52 of the actuator 52 contacts the rack diameter portion 61b of the cam 61, as shown in FIG. Abut At this time, since the other end 52b does not contact the sensor 63, the sensor 63
It is FF.

Next, as shown in FIG. 13, when the large-diameter planetary gear 10b comes into contact with the feed-side semicircle internal gear 7b, the end 52a of the actuator 52
And the other end 5
2b contacts the sensor 63, and the sensor 63 is turned on. Thereafter, when the large-diameter planetary gear 10b further revolves,
As shown in FIG. 14, the meshing between the large-diameter planetary gear 10 b and the feed-side semicircular internal gear 7 b is released, and the small-diameter planetary gear 10 c meshes with the upper rack 5 instead. At this time, the end 52a of the actuator 52 contacts the rack diameter portion 61e of the cam 61, the other end 52b does not contact the sensor 63, and the sensor 63 is turned off.

Thereafter, the small-diameter planetary gear 10c further revolves and reaches the start position α ₃ . At this time, the end 52a of the actuator 52 abuts against the start diameter portion 61f of the cam 61 and is formed on the projection of the start diameter portion 51a. Turns ON. Further, when the small-diameter planetary gear 10c revolves and passes through the upper rack 5, as shown in FIG.
2a is in contact with the rack diameter portion 61d of the cam 61, and the other end 52b is not in contact with the sensor 63;
Becomes OFF.

Thereafter, when the small-diameter planetary gear 10c further revolves and the meshing with the upper rack portion 5 is released, as shown in FIG. 16, the large-diameter planetary gear 10b is moved to the return side semicircle internal gear portion 7a. Mesh with. At this time, the end 52a of the actuator 52 abuts on the semi-circular in-gear gear diameter portion 61c of the cam 61, and the other end 52b contacts the sensor 63, whereby the sensor 63 is turned ON.

Next, as shown in FIG. 17, when the large-diameter planetary gear 10b meshes with the lower rack 6, the sensor 63 is turned off, as in FIG.

Next, the ON / OFF state of the sensor 63 when the platen position detecting device 60 operates will be described with reference to the time chart of FIG.

First, when the copy switch (not shown) is turned on and the large-diameter planetary gear 10b meshes with the lower rack 6, the sensor 63 is off. Next, the large-diameter planetary gear 10b is connected to the feed-side semicircle internal gear 7.
When meshing with b, the sensor 63 is turned ON. Then, when the small-diameter planetary gear 10c is adapted to mesh with the upper rack unit 5, the sensor 63 is once turned OFF and then a small diameter planet gear 10c is the start position alpha _3, the sensor 63 is temporarily turned ON, then , Immediately, small diameter planetary gear 1
0c passes through the upper rack 5, ie, the optical system 2
0 while the original 25 is being scanned.
Becomes OFF.

When the large-diameter planetary gear 10b meshes with the return side semicircle internal gear 7a, the sensor 6
3 is turned on, and the sensor 63 is turned off when the large-diameter planetary gear 10b passes through the lower rack portion 6 soon.
Eventually the copying ends.

By the way, the control device 31 of the platen position detecting device 60 of this embodiment outputs the ON signal output from the sensor 63.
It has a function as output determination means for determining whether ON / OFF has been repeated within a predetermined time based on the signal.

[0078] Thus, in the time chart, when the small-diameter planetary gears 10c becomes the start position alpha ₃ is briefly the sensor 63 is ON, OFF, ON, O
Since FF operation, whereby, the control unit 31 is adapted to detect that the small-diameter planetary gears 10c becomes the start position alpha _3.

Also, in the original platen driving device 3 of the present embodiment, the main power supply of the copying machine main body 1 is turned on as in the first embodiment.
When the large-diameter planetary gear 10b meshes with the return-side semicircle internal gear 7a or the feed-side semicircle internal gear 7b at this time, the control device 31 controls the large-diameter planetary gear 10b.
The main motor 43 is operated until the meshing with the return side semicircle internal gear portion 7a or the feed side semicircle internal gear portion 7b is released.

That is, as shown in the flowchart of FIG. 18, when the main power of the copying machine is turned on (S11), it is determined whether or not the sensor 63 is turned on (S12).
If the sensor 63 is not ON in S12, a copy switch (not shown) is turned ON (S13), whereby the main motor 43 is turned ON (S14). Then, the control device 31 determines whether the sensor 63 has output two ON signals within a predetermined time (S15).
The control device 31 starts the copying process by determining that two ON signals have been output within the predetermined time (S16).

On the other hand, if the sensor 63 is ON in S12, the large-diameter planetary gear 10b
a, or the position of the feed side semicircle internal gear 7b, the control device 31 turns on the main motor 47 (S17). Next, the sensor 63 is turned on.
It is determined whether or not this is the case (S18), and S18 is repeated until the sensor 63 is turned off. Next, the large-diameter planetary gear 10b
When the meshing between the return side semicircle internal gear 7a or the feed side semicircle internal gear 7b is released, the sensor 63 is turned on.
As a result, the main motor 43
FF is performed (S19), and the process proceeds to S13.

As described above, in the original platen position detecting device 60 of this embodiment, the end 52 a of the actuator 52 is
The other end 52b of the actuator 52 comes into contact with the sensor 63 only when it comes into contact with the semi-circular internal gear diameter portions 61a and 61c, so that the large-diameter planetary gear 10b moves the return-side semi-circular internal gear portion. 7a or the feed-side semicircle internal gear 7b can be detected.

[0083] Also, when the small-diameter planetary gears 10c moves in the vicinity of the start position alpha ₃ of the endless gear 8, i.e., the feed-side semicircular internal gear portion 7b of the small-diameter planetary gears 10c is endless gear 8, on the rack part 5, when passing through the start position alpha ₃ and the upper rack unit 5, the sensor 6
ON / OFF of 3 is performed within a short time.

At this time, the control device 31 as output determination means determines whether ON / OFF has been repeated within a predetermined time based on the ON signal output from the sensor 63. Therefore, by previously setting the predetermined time can be small planetary gear 10c is detected to be the start position alpha ₃ of the endless gear 8, which in other words the document stand 2 is in the scanning start position P _2.

As a result, it is possible to detect which part of the endless gear 8 the planetary gears 10b and 10c are located on the basis of the difference in the output waveform of the sensor 63.

In addition, since only one sensor 63 is used in terms of structure, it is possible to reduce the cost and to prevent the apparatus from becoming complicated.

[0087]

According to the first aspect of the present invention, as described above, the substantially circular cam which is integrally rotated with the connecting plate is provided at the center of rotation of the connecting plate. On the outer circumference of this cam, the start radius is formed so that the start position of the endless gear is detected, and the radius of the cam is different from the start radius to detect the position of the semicircular internal gear. The two semi-circular internal gear diameter portions and two rack diameter portions having further different radii for detecting the rack portion are formed, while the end portion abuts on the outer periphery of the cam and is substantially at the center. Is provided with a contact member having a fulcrum serving as a rotation center, and a first contact and a second contact are provided near the other end of the contact member opposite to the cam. The contact point and the second contact point are such that the end of the abutment member is at the rack diameter of the cam. The other end of the contact member does not contact the first contact and the second contact when in contact, and the other end of the contact member when the end of the contact member contacts the semi-circular gear of the cam. When the end contacts only the first contact and the end of the contact member contacts the start diameter of the cam, the other end of the contact member is provided at a position where it contacts only the second contact. Configuration.

Accordingly, when the end of the contact member contacts the rack diameter portion of the cam, the other end of the contact member is connected to the first end.
When the end of the contact member abuts on the semi-circular internal gear diameter portion having a radius different from the rack diameter portion of the cam without contacting the contact point and the second contact point, the other end portion of the contact member is connected to the first gear. When the end of the contact member comes into contact with the start diameter portion having a further different radius of the cam, the other end of the contact member contacts only the second contact. Can be detected at the position of the semicircular internal gear portion of the endless gear.

According to the second aspect of the present invention, as described above, in the original platen position detecting device of the original platen driving device, the main power supply of the apparatus is turned on. When the other end of the contact member is in contact with the first contact, motor control means for rotating the motor until the other end of the contact member does not contact the first contact is provided. Configuration.

Thus, in addition to the effect of claim 1, when the main power supply of the apparatus is turned on, if the other end of the contact member is in contact with the first contact point, When the gear is located in the semicircular internal gear portion of the endless gear, the motor control means rotates the motor until the other end of the contact member does not contact the first contact. The gear can be moved to the rack of the endless gear. As a result, the original table can be manually moved horizontally and returned to the start position.

Further, in the document platen driving device of the image forming apparatus according to the third aspect of the present invention, a substantially circular cam which rotates integrally with the connecting plate is provided at the center of rotation of the connecting plate as described above. At the same time, on the outer periphery of the cam, there are two semi-circular gear teeth for detecting the position of the semi-circular gear and a semi-circular gear for detecting the rack. And a start radius provided on the rack of the endless gear and having a radius different from that of the rack to detect a start position. Abuts, and a contact member having a fulcrum serving as a center of rotation is provided at substantially the center, and in the contact member,
The other end of the contact member contacts the contact only when the end of the contact member contacts the semi-circular internal gear diameter portion of the cam near the other end opposite to the cam. At the same time, an output judging means for judging whether or not ON / OFF has been repeated within a predetermined time based on the ON signal output from the contact point is provided.

As a result, the other end of the abutment member contacts the contact only when the end of the abutment member abuts on the semi-circular internal gear diameter portion of the cam. It can be detected whether or not it is located in the internal gear portion.

Further, when the planetary gear moves near the start position of the endless gear, that is, when the planetary gear passes through the semicircular internal gear portion, the rack portion, the start position and the rack portion of the endless gear. Determines whether or not ON / OFF has been repeated within a predetermined time based on the ON signal output from the contact point. Therefore, by setting the predetermined time in advance, it is possible to detect that the planetary gear is at the start position of the endless gear.

As a result, due to the difference in the output waveform of the contact,
It is possible to detect at which part of the endless gear the planetary gear is located.

Further, since only one contact is used, it is possible to reduce the cost, and it is possible to prevent the device from being complicated.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an original platen position detecting device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a state of the document table position detecting device when a large-diameter planetary gear meshes with a feed-side semicircular internal gear.

FIG. 3 is a schematic configuration diagram illustrating a state of the platen position detection device when the small-diameter planetary gear is at a start position.

FIG. 4 is a schematic configuration diagram showing a state of the platen position detecting device when the small-diameter planetary gear is in the upper rack.

FIG. 5 is a schematic configuration diagram showing a state of the platen position detecting device when the small-diameter planetary gear is at the end of the upper rack.

FIG. 6 is a schematic configuration diagram showing a state of the platen position detecting device when the small-diameter planetary gear is in the return-side semicircular internal gear.

FIG. 7 is a schematic configuration diagram illustrating a state of the platen position detection device when the small-diameter planetary gear is in the lower rack.

FIG. 8 is a flowchart showing the operation of the document table position detecting device when the main power supply is turned on.

FIG. 9 is an overall configuration diagram showing a copying machine provided with the platen position detecting device.

FIG. 10 is a configuration diagram showing a platen driving device including the platen position detecting device.

FIG. 11 is a block diagram showing a control device of a platen driving device including the platen position detecting device.

FIG. 12 is a schematic configuration diagram showing an original platen position detecting device according to another embodiment of the present invention.

FIG. 13 is a schematic configuration diagram showing a state of the platen position detection device when a large-diameter planetary gear meshes with a feed-side semicircle internal gear.

FIG. 14 is a schematic configuration diagram showing a state of the platen position detecting device when the small-diameter planetary gear starts to mesh with the upper rack portion.

FIG. 15 is a schematic configuration diagram showing a state of the platen position detecting device when the small-diameter planetary gear is in the upper rack.

FIG. 16 is a schematic configuration diagram showing a state of the platen position detecting device when the small-diameter planetary gear is in the return-side semicircular internal gear.

FIG. 17 is a schematic configuration diagram illustrating a state of the platen position detection device when the small-diameter planetary gear is in the lower rack.

FIG. 18 is a timing chart showing the ON / OFF state of the sensor with respect to the position of the planetary gear in the endless gear.

FIG. 19 is a flowchart showing the operation of the document table position detecting device when the main power is turned on.

FIG. 20 is a front view showing a structure near a document table of a copier including a conventional document table driving device.

FIG. 21 is a front view of a main part showing a platen driving device in the copying machine.

[Explanation of symbols]

2 Document table 3 Document table driving device 5 Upper rack section (rack section) 6 Lower rack section (rack section) 7a Return side semicircle internal gear section (semicircular internal gear section) 7b Feed side semicircle internal gear section (Semi-circular internal gear portion) 8 Endless gear 9 Sun gear 9a Input shaft (rotating shaft) 10b Large diameter planetary gear (planetary gear) 10c Small diameter planetary gear (planetary gear) 11 Connecting plate 31 Control device (motor control means, output) Judgment Means) 43 Main Motor (Motor) 50 Platen Position Detector 51 Cam 51a Start Diameter Part 51b Semicircle Internal Gear Diameter Part 51c Rack Diameter Part 51d Semicircle Internal Gear Gear Diameter Part 51e Rack Diameter Part 52 Actuator (Contact) 52a End 52b Other End 53 First Sensor (First Contact) 54 Second Sensor (Second Contact) 60 Platen Position Detector 61 Cam 61a Semi-circular Inner Gear Diameter 61b rack diameter portion 61c semicircular internal gear diameter 61d rack diameter 61e rack diameter 61f start diameter 63 sensor (contact) alpha ₃ start position

Claims (3)

(57) [Claims] 1. A rack comprising two rack portions provided in parallel with their tooth surfaces facing each other and two semicircular internal gear portions respectively connecting ends of these rack portions, and are integrated with a document table. An annular endless gear which is connected in a reciprocally movable manner, and a sun gear which is provided at a fixed position at an intermediate portion between the two rack portions in the endless gear, and to which a driving force of a motor is inputted, A planetary gear is provided between the sun gear and the endless gear so as to revolve by meshing with the two gears, and is rotatably connected to a rotation shaft of the sun gear and supports the gear shaft of the planetary gear. A platen position detection device for a platen driving device having a connection plate that rotates along an endless gear, wherein a rotation center of the connection plate has a substantially circular cam that rotates integrally with the connection plate. Is provided and this On the outer circumference of the cam,
A start radius portion for detecting the start position of the endless gear and two semicircles formed so that the radius of the cam is different from the start radius portion for detecting the position of the semicircular in-gear gear portion. A tooth gear diameter portion and two rack diameter portions having different radii for detecting the rack portion are formed, while an end portion abuts on the outer periphery of the cam, and has a fulcrum serving as a rotation center at a substantially center. A contact member is provided, and a first contact and a second contact are provided near the other end of the contact member on the side opposite to the cam, and the first contact and the second contact are provided.
The contact is such that when the end of the contact member abuts against the rack radial portion of the cam, the other end of the contact member is connected to the first contact and the second contact.
When the end of the contact member comes into contact with the semi-circular internal gear diameter of the cam without contacting the contact, the other end of the contact member contacts only the first contact and the end of the contact member. A platen position detecting device for a platen driving device, wherein the other end of the contact member is provided at a position where it contacts only the second contact when the portion comes into contact with the start diameter portion of the cam. 2. A rack comprising two rack portions provided in parallel with their tooth surfaces facing each other and two semicircular internal gear portions respectively connecting ends of these rack portions, and are integrated with the document table. An annular endless gear which is connected in a reciprocally movable manner, and a sun gear which is provided at a fixed position at an intermediate portion between the two rack portions in the endless gear, and to which a driving force of a motor is inputted, A planetary gear is provided between the sun gear and the endless gear so as to revolve by meshing with the two gears, and is rotatably connected to a rotation shaft of the sun gear and supports the gear shaft of the planetary gear. A platen position detection device for a platen driving device having a connection plate that rotates along an endless gear, wherein a rotation center of the connection plate has a substantially circular cam that rotates integrally with the connection plate. Is provided and this On the outer circumference of the cam,
A start radius portion for detecting the start position of the endless gear and two semicircles formed so that the radius of the cam is different from the start radius portion for detecting the position of the semicircular in-gear gear portion. A tooth gear diameter portion and two rack diameter portions having different radii for detecting the rack portion are formed, while an end portion abuts on the outer periphery of the cam, and has a fulcrum serving as a rotation center at a substantially center. A contact member is provided, and a first contact and a second contact are provided near the other end of the contact member on the side opposite to the cam, and the first contact and the second contact are provided.
The contact is such that when the end of the contact member abuts against the rack radial portion of the cam, the other end of the contact member is connected to the first contact and the second contact.
When the end of the contact member comes into contact with the semi-circular internal gear diameter of the cam without contacting the contact, the other end of the contact member contacts only the first contact and the end of the contact member. The other end of the contact member is provided at a position where it contacts only the second contact when the portion comes into contact with the start diameter portion of the cam, and when the main power supply of the apparatus is turned on, the contact member is turned off. The other end is first
When the contact member is in contact with the contact point, the other end of the contact member is in the first position.
An original platen position detecting device for an original platen driving device, further comprising motor control means for rotating a motor until the motor stops contacting a contact. 3. A rack comprising two rack portions provided in parallel with their tooth surfaces facing each other and two semicircular in-gear gear portions connecting respective ends of these rack portions, respectively. An annular endless gear which is connected in a reciprocally movable manner, and a sun gear which is provided at a fixed position at an intermediate portion between the two rack portions in the endless gear, and to which a driving force of a motor is inputted, A planetary gear is provided between the sun gear and the endless gear so as to revolve by meshing with the two gears, and is rotatably connected to a rotation shaft of the sun gear and supports the gear shaft of the planetary gear. A platen position detection device for a platen driving device having a connection plate that rotates along an endless gear, wherein a rotation center of the connection plate has a substantially circular cam that rotates integrally with the connection plate. Is provided and this On the outer circumference of the cam,
Two semicircular gear teeth for detecting the position of the semicircular internal gear portion, and two rack diameter portions having different radii from the semicircular internal gear diameter portion for detecting the rack portion; In order to detect the start position provided on the rack portion of the endless gear, a start diameter portion having a different radius from the rack diameter portion is formed, while an end of the cam comes into contact with the outer periphery of the cam and the center of rotation is substantially at the center. A contact member having a fulcrum is provided, and the contact member has a contact in the vicinity of the other end on the opposite side to the cam, and the end of the contact member has a semi-circular internal gear gear diameter of the cam. The other end of the contact member is provided at a position where it contacts the contact only when contacting the portion, while the O output from the contact is
An original platen position detecting device for an original platen driving device, comprising an output judging means for judging whether ON / OFF has been repeated within a predetermined time based on an N signal.