JPH0527336A - Driving mechanism for traveling object - Google Patents

Abstract

PURPOSE:To surely move a lens holder to a prescribed position. CONSTITUTION:Since a wire which is bent to be laid between a proper driving pulley 6-1, a slave pulley 6-2 and an idler pulley 6-3 is fixed on a mounting part 4, a lens holder 2 for supporting a lens 1 and moving it to the prescribed position is moved by rotating a driving pulley 61, The wire 5 is constituted by helically winding a polyurethane wire 5b around a core wire 5a formed of a stainless steel, and also a central groove 6a in which the core wire 5a is fitted and an inclined groove 6b in which the helical wire 5b of the wire 5 is fitted are formed on the driving pulley 6-1, so that the wire 5 can be moved by rotating the driving pulley 6-1 without slipping, thus, the lens holder 2 can be moved to the prescribed position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving body drive mechanism for moving a movable body provided to be movable to a desired position.

[0002]

2. Description of the Related Art In a copying machine or the like, in order to optically scan a document, an optical scanning means such as a document table or an optical system is moved. Further, not only such a moving body related to the optical scanning means but also a moving body such as a lens in which the lens or the like is moved to a predetermined position according to the magnification according to the change of the copy magnification.

FIG. 4 shows an outline of a copying machine. In the figure, the document 39 placed on the document table 31 is scanned by the movement of the optical system. The optical system includes a light source 32, a document-side mirror, a first right-angled mirror 34, a lens 35, a second right-angled mirror 36, and a photoconductor-side mirror 37. The light source 32 and the document-side mirror 33 are integrally provided and move below the document table 31 in the scanning direction when scanning the document 39. The first right-angled mirror 34 moves in the same direction so as to follow it. However, the photoconductor side mirror 37
Is fixed. Also, the lens 35 and the second right-angled mirror 36. It moves only when the magnification is changed, and is fixed when scanning the document 39.

When scanning is performed, first, as shown by the alternate long and short dash line in the drawing, the light emitted from the light source 32 is reflected by the original 39 on the original table 31.
It is irradiated one after another. Then, the light including the image information of the original 39 is reflected by the original-side mirror 33 and the first right-angle mirror 34.
Is reflected by and reaches the lens 35. Then, the light passing through the lens 35 is reflected by the second right-angle mirror 36 and the photoconductor-side mirror 37, and is applied to the exposed portion on the surface of the photoconductor drum 38.

In this case, the document-side mirror 33 provided integrally with the light source 32 moves in the scanning direction at a scanning speed corresponding to the rotation speed of the photosensitive drum 38. Then, the first right-angled mirror 34 moves in the same direction at a speed half the scanning speed. Therefore, the optical path distance a from the document 39 on the document table 31 to the lens 35 via the document-side mirror 33 and the first right-angled mirror 34 is constant regardless of the scanning position. The optical path distance b from the lens 35 to the exposed portion on the surface of the photoconductor drum 38 via the second right-angle mirror 36 and the photoconductor side mirror 37 is always constant because these optical systems are fixed during scanning. is there. Therefore, when scanning the document 39, the optical path distance a and the optical path distance b are always kept constant. In addition,
In the case of a platen moving type copying machine, since the optical system does not move during scanning, the optical path distance a and the optical path distance b are of course constant.

As described above, in the copying machine, when the document is scanned, the document table 31 or a part of the optical system, that is, the light source 32 and the document-side mirror 33 are moved in the scanning direction, but they are moving bodies. As a drive mechanism for moving the mirror 33 and the like, a wire is wound around a drive pulley and a driven pulley that are appropriately arranged, and the wire is transferred to the drive pulley in accordance with the rotation, thereby moving the moving body. It is generally done.

Further, by changing the optical path distance a and the optical path distance b with respect to the focal length f of the lens 35, the projection magnification of the original document on the photosensitive drum can be variously changed. For that purpose, it is possible by moving the lens 35 and the second right-angled mirror 36. That is, the relationship between the optical path distance a from the document 39 to the lens 35, the optical path distance b from the lens 35 to the surface of the photosensitive drum 38, and the focal length f of the lens 35 is 1 / a + 1 / b = 1 / f. It is well known as can be expressed by a formula. Further, in order to make the magnification of projecting the image of the original document on the photosensitive drum 38 equal, a = b = 2f, and optical means such as a mirror may be arranged in that positional relationship.

Therefore, it is well known that the magnification m projected on the photosensitive drum 38 has a relation of m = a / b. Therefore, if the projection magnification m is determined, the optical path distances a and b are determined. That is, the optical path distances a and b are a = f (1 + 1 / m) b = f (m + 1) depending on the magnification.

As described above, when the magnification m is determined, the optical path distances a and b are changed according to the magnification m, so that projection on the photosensitive drum 38 according to the magnification can be performed. Therefore, as shown in FIG. 4, the lens 35 is moved according to the magnification m to adjust the optical path distance a from the document 39 to the lens 35 so as to be the value of the above expression, and at the same time, the second right-angle mirror 36 is provided. Is moved to adjust the optical path distance b from the moved lens 35 to the exposure section. If one mirror is used instead of the second right-angled mirror 36 and the light is reflected directly toward the exposed portion of the photoconductor drum 38 without passing through the photoconductor-side mirror 37, this one mirror is used. It is necessary to move and also change its angle.

As described above, it is necessary to move the lens, the mirror, etc., as described above, even when the magnification of the original document projected on the photosensitive drum 38, that is, the copying magnification m is variously set. A wire or the like is also used for the mechanism for moving the moving body such as the lens and the mirror. For example, the example is shown in FIG. This conventional lens moving device will be described. This relates to a lens moving mechanism based on one side reference.

The lens 35 is fixed to the lens holder 41. It is slidably attached to the shaft 42 along the Y direction orthogonal to the optical axis X of the lens 35. The lens holder 41 is always biased by the spring 43 toward one end side in the Y direction. Furthermore, this lens holder 41
A roller 44 is attached to an end portion on one end side of the. The optical axis X of the lens 35 is provided on the one end side of the roller 44.
A guide plate 51 is arranged along the X ′ direction having an inclination of an angle θ with respect to the direction. The guide plate 51 is fixed to a copying machine (not shown). The surface of the guide plate 51 that is in contact with the roller 44 is not linear, but is a curved surface that follows each lens position of the lens 35 when the copy magnification is changed.

Both ends of the shaft 42 are fixed to the lens moving member 45. One end of the lens moving member 45 is slidably attached to the shaft 46 along the X ′ direction. Both ends of the shaft 46 are fixed to the copying machine. A roller 47 is provided at the other end of the lens moving member 45. The roller 47 rolls on a rail 48 along the X'direction. Also, a wire attachment portion 49 is provided so as to project from the end on the one end side of the lens moving member 45. The wire attachment portion 49 is attached to the wire 50 stretched in the X'direction.

In the lens moving device having this structure, the wire 50 is stretched by a wire driving device (not shown), for example, a driving pulley and a driven pulley, and is moved in the X direction when the copy magnification is changed. . Then, the lens moving member 4 in which the wire attaching portion 49 is attached to the wire 50
5 is guided by the shaft 46 and translates in the X'direction. The lens holder 41 moves in parallel in the X ′ direction according to the lens moving member 45. In addition, at this time, the lens holder 41 is always urged by the spring 43 to press the roller 44 against the guide plate 51. Therefore, the lens holder 41 is displaced along the curved surface of the guide plate 51 in the Y direction along with the movement in the X ′ direction.

As a result, the conventional lens moving device can move the lens 35 to the position corresponding to each magnification by driving the wire 50.

[0015]

However, a wire is used to move a moving body such as a lens according to the drive of the original scanning means (moving body) of the copying machine or the copying magnification, and this wire is used. The drive pulley and the driven pulley for driving the motor are designed so as not to slip.
That is, if the slip occurs, the original scanning by the optical scanning means is not normally performed, and the unclear image cannot be projected on the photosensitive drum, or the magnification corresponding to the copy magnification cannot be set.

Therefore, in order to prevent slipping, a wire is wound around a drive pulley or the like a plurality of times, and a spring or the like is attached to a pulley rotatably supported in the middle of the wire stretched so as not to loosen. It is necessary to provide a tensioning means. Therefore, assembly and the like becomes very troublesome.

An object of the present invention is to provide a drive mechanism capable of reliably driving a wire so that the wire does not slip on a drive pulley and a driven pulley when the wire is driven.

[0018]

According to the present invention, there is provided a drive mechanism for a moving body, in which a wire is endlessly wound around a moving body provided movably around a driving pulley and a suitably driven pulley.
By connecting the drive pulley to a drive source and rotating it,
In the drive mechanism of the moving body formed by moving the moving body,
The wire is configured by spirally winding a wire around the core wire, and the drive pulley is formed with a groove for guiding the core wire of the wire and an inclined groove corresponding to the spiral wire body. .

[0019]

According to the drive mechanism for a moving body of the present invention, the drive pulley rotates the drive pulley to drive the wire. At this time, an inclined groove is formed in the drive pulley that drives the wire, in addition to the groove that guides the wire itself. Therefore, the spirally-shaped wire body formed on the wire fits into this inclined groove. Crowded. Therefore, the wire is reliably driven according to the rotation of the drive pulley without slipping. Thereby, the moving body can be moved to a required position and at a required speed.

Therefore, it is not necessary to wind the wire around the drive pulley or the like a plurality of times, and the assembly can be simplified.

[0021]

EXAMPLES Examples of the present invention will be described below. FIG. 1 is a front view showing an example of a wire structure in the present invention, and FIG. 2 is a front view showing an example of a drive pulley for driving the wire.

The wire and drive pulley shown in FIGS. 1 and 2 are applied, for example, to a drive mechanism in the moving body of the lens body of the copying machine shown in FIG. Referring to FIG. 3, the lens moving device of the copying machine indicates the lens 1 of the optical system according to the copy magnification.
Is a device for moving in the X'direction inclined by an angle θ with respect to the optical axis X and also for displacing it in the Y direction orthogonal to the optical axis X. This lens 1 is fixed to a lens holder 2. The lens holder 2 is supported on the guide rails 3 and 3 and is arranged so as to be slidable on a plane. The guide rails 3, 3 are support members provided along the X'direction and are fixed to the copying machine main body. At both ends of the lens holder 2 in the Y direction,
Wire attachment portions 4 and 4 are formed. Then, the wire attaching portions 4 and 4 are provided on both sides of the lens holder 2,
It is attached to each wire 5 stretched in the X'direction.

The wire 4 comprises a drive pulley 6-1 and a driven pulley 6-2, and a number of appropriately arranged idler pulleys 6
An endless wire drive system for moving the lens holder 2 of the lens 1, which is the movable body, is constructed by being wound around by -3. As the wire 5, a synchromesh rope (made by Asahi Mini Rope Co., Ltd.) is used. As shown in detail in FIG. 1, this synchromesh rope is formed by spirally winding a polyurethane wire 5b around a core wire 5a made of threadless.

On the other hand, with respect to the wire 5, the drive pulley 6
-1 is a center groove 6 on the peripheral surface of the pulley as shown in FIG.
In addition to forming a, a large number of inclined grooves 6b having an inclination with respect to the center groove 6a are formed.
As a matter of course, the inclined groove 6b is formed at an angle such that the polyurethane 5b of the wire 5 fits therein. Further, similarly to the drive pulley 6-1, the driven pulley 6
-2 also has a structure as shown in FIG.

Due to the above structure, the drive pulley 6
When the wire 5 is stretched over the -1 and the driven pulley 6-2, the core wire 5a fits in the center groove 6a and the polyurethane wire 5b fits in the inclined grooves 6b. Therefore, slippage between the drive pulley 6-1 and the driven pulley 6-2 is prevented, so that the wire 5 can be driven in accordance with a predetermined number of rotations without providing tension means or the like for properly tensioning the wire 5. Further, as a result, it is not necessary to wind the wire 5 around a drum or the like several times, and the assembly of the device for the entire moving mechanism can be facilitated.

The idler pulley 6-3 arranged in the drive mechanism using the wire 5 has a shaft to which it is rotatably attached fixed to the tension adjusting plate 16. The tension adjusting plate 16 is attached to the main body of the copying machine so that its fixed position can be adjusted. Therefore, the tension of the wire 5 in the wire 5 can be adjusted by changing the mounting position of the tension adjusting plate 16.

The endless wire drive mechanism using the wire 5 is driven by a stepping motor which is a drive source (not shown). The rotation of the stepping motor is first transmitted to the first gear 7-1. The rotation of the first gear 7-1 is transmitted to the second gear 7-2. The drive pulley 6-1 is coaxially attached to the second gear 7-2. Therefore, when the rotation of the stepping motor is transmitted to the drive pulley 6-1,
The wire 5 is transferred, so that the lens holder 2 moves.

In this wire drive mechanism, two sets of idler pulleys 6-3 are arranged on both sides of the lens holder 2, and the wires 5 hung on each set are stretched in parallel with each other in the X'direction. It has become so. Further, these wires 5 are laid so as to be transferred in the same direction. Then, the wires 5 stretched around these two sets of idler pulleys 6-3 ... Are attached to the wire attaching portions 4 and 4 at both ends of the lens holder 2 as described above. Therefore, the lens holder 2 moves in the X'direction while sliding on the guide rails 3 and 3 as the wire 5 is transferred. Further, at this time, since both ends of the lens holder 2 are supported by these wires 5, the lens holder 2 is translated while the optical axis X of the lens 1 is directed in a certain direction. In FIG. 3, when the drive pulley 6-1 rotates counterclockwise (CCW), the lens holder 2 moves diagonally upward to the right.

A guide pin 8 is provided on the lens holder 2 so as to project to the back side. A curved guide plate 9 is arranged between the guide rails 3 and 3 along the X'direction and fixed to the main body of the copying machine. Curved guide plate 9
The guide pin 8 of the lens holder 2 is fitted in the guide groove 9a extending along the X'direction on the upper surface of the guide pin. Therefore, the guide pin 8 is restricted in position in the Y direction by the guide groove 9a when the lens holder 2 moves in the X'direction. Therefore, the lens holder 2
While moving in the X'direction, it is guided by the guide groove 9a and is slightly displaced in the Y direction. The guide groove 9a shows an accurate curve to which the lens 1 should move according to the copy magnification.

Further, the lens holder 2 is provided with a photo interrupter 10 at one end. The slit plate 11 is fixed to the main body of the copying machine. This slit plate 11 is arranged so as to block the optical axis of the photo interrupter 10 as the lens holder 2 is moved.
It is arranged along the direction. Also, this slit plate 1
1, a plurality of slits 11a are formed, and the optical axis of the photo interrupter 10 passes at this position. Therefore, if the positions of the slits 11a are appropriately determined and the output of the photo interrupter 10 is detected, the moving position of the lens holder 2 can be actually known.

The second gear 7-2 transmits the rotation to the third gear 7-3. The third gear 7-3 is
Further, the rotation is transmitted to the fourth gear 7-4. A cam 12 is attached to the fourth gear 7-4. The cam 12 is a second lens located behind the lens 1 in the optical system.
The right angle mirror 13 is moved. However, when the lens 1 is a zoom lens, this second right angle mirror 1
There is no need to move 3.

The driven pulley 6-2 arranged in the wire drive mechanism is different in the direction of the rotating shaft from the drive pulley 6-1 and the like. The driven pulley 6-2 is coaxially mounted with the first driven gear 14-1. The first driven gear 14-1 transmits the rotation to the second driven gear 14-2. The rotation shaft of the second driven gear 14-2 is output to the outside of the device as the drive transmission shaft 15. The drive transmission shaft 15 is configured to switch the gear ratio of a transmission (not shown) according to the rotation amount thereof. This transmission is arranged in a drive device that scans the optical system, and the scanning speed of the optical system can be changed according to the gear ratio.

The operation of the lens moving device having the above configuration will be described.

When the copy magnification is set by an operator's operation or the like, the stepping motor is rotated by a predetermined amount in response to the setting, and the drive pulley 6-1 of the wire drive mechanism is rotated to transfer the wire 5. . Then, at both ends of the lens holder 2, the wires 5 are transferred in the same X'direction at the same speed, so that the lens holder 2 also tries to move in the same direction at the same speed. However, since the guide pin 8 is fitted in the guide groove 9a of the curved guide plate 9, the lens holder 2 is guided by the guide groove 9a and is slightly displaced in the Y direction as well. Therefore, the lens holder 2 moves in the optical axis X direction according to the set copy magnification, and also moves in the Y direction by a predetermined amount.

Therefore, the lens 1 can move on an accurate curve to be moved for changing the copy magnification.

The fact that the lens holder 2 has reached the predetermined position can be detected by the photo interrupter 10. Further, the wire driving mechanism driven by the stepping motor can take out the rotational driving force in which the directions of the rotation axes are different by the driven pulley 6-2 by utilizing the characteristics of the wire 5. And this driven pulley 6
The amount of rotation of the drive transmission shaft 15 connected to -2 depends on the copy magnification. Therefore, the gear shift of the transmission for adjusting the scanning speed of the optical system can be easily performed by the drive transmission shaft 15 without using another transmission.

Also in the driven pulley 6-2, as shown in FIG.
Since the drive pulley 6-1 has the same configuration as that shown in FIG. 6, its rotation is ensured, and the rotation can be transmitted to another transmission device as described above.

[0038]

As described above, according to the present invention, since the wire is reliably driven by the drive pulley without slipping, the moving body can be transferred at a required position and at a required speed. . Further, it can be realized by a simple mechanism without providing any special means therefor.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a wire structure according to the present invention.

FIG. 2 is a plan view showing an example of the structure of a drive pulley according to the present invention.

FIG. 3 is a plan view of a lens moving device of a copying machine to which a wire driving mechanism according to the present invention is applied.

FIG. 4 is a sectional view showing a schematic configuration of a copying machine.

FIG. 5 is a plan view of a lens moving device of a copying machine showing an example of a conventional wire driving mechanism.

[Explanation of symbols]

1 lens 2 lens holder 5 wires 5a core wire 5b Spiral polyurethane wire 6-1 Drive pulley 6-2 Driven pulley 6-3 Idler pulley 6a Wire guide groove 6b inclined groove

Claims (2)

[Claims] 1. A moving body which is endlessly wound around a movable body which is movably mounted on a driving pulley and a suitably arranged driven pulley, and the driving pulley is connected to a driving source to rotate the moving body. In the drive mechanism of the moving body, the wire is spirally wound around the core wire, and the drive pulley has a groove and a spiral shape for guiding the core wire of the wire. A drive mechanism for a moving body, characterized in that an inclined groove is formed in accordance with the linear body of FIG. 2. The drive mechanism for a moving body according to claim 1, wherein the driven pulley is also provided with a groove for guiding the core wire of the wire and an inclined groove corresponding to the spiral wire body.