JPH0432664Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention reciprocates the document mounting table and optical system of a copying machine, or the optical system of a document reading device, as the output shaft rotates forward and backward. This relates to a drive device for.

(Prior art) For example, in a copying machine, if the copying machine has a movable document table, the document table is moved, or if the optical system is a movable type, the optical system is moved at a speed higher than the set speed in the scanning process. It is desirable to make the reverse movement at the same time in order to shorten the copying operation time.

Conventionally, as shown in FIG. 7, the first and second optical systems X and Y are provided so as to be movable back and forth in the arrow direction P, and both of the reciprocating movement ranges of the two optical systems X and Y are provided. Rotating bodies 38 and 39 are arranged on the outside, and an idle rotating body 40 is provided in the second optical system Y, and a fastening body 41 is attached to the first optical system X. It is wound around the freely rotating rotating body 40 and fixed to the fastening body 41, and further,
The transmission cable 42 is wound around the rotating bodies 39 and 38 on both sides and the free rotating body 40, and both ends of the transmission cable 42 are fixed. Then, by forward and reverse rotation of the input shaft 43 with respect to one of the rotating bodies 38, , constitutes an optical system reciprocating mechanism B that sets the moving speed of the second optical system Y to 1/2 that of the first optical system X and reciprocates both optical systems X and Y in the same direction.

The reciprocating mechanism B has an input shaft 43 and an output shaft 4 which can be freely switched between forward and reverse rotations relative to the input shaft 43.
4, the first rotary type comprises a pair of gears G ₁ and G ₂ for reciprocating the optical systems X and Y at a set speed.
A transmission mechanism D and a rotary second transmission mechanism E including _four pairs of gears G ₃ and G that drive the motor M in reverse to move the optical systems X and Y at a higher speed than the set speed are installed, and , the first and second transmission mechanisms D,
Gears G ₂ and G ₄ on one side of E are mounted on a shaft via electromagnetic clutches C ₁ and C ₁ .

(Problem to be solved by the invention) According to the above configuration, by appropriately setting the speed ratio of the second transmission mechanism E, the optical systems X and Y are moved back at twice or three times the set speed. However, two expensive electromagnetic clutches C ₁ ,
C ₁ is required, and the control system for the clutches C ₁ and C ₁ is also complicated.

The present invention aims to eliminate the above-mentioned drawbacks through simple improvements.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an input shaft for the reciprocating mechanism for the document placing table or the optical system in the driving device for the document placing table or the optical system described at the beginning. a rotary first transmission mechanism that extends between the output shaft and moves the document mounting table or the optical system forward at a set speed when the output shaft rotates forward; and a rotary first transmission mechanism that moves the document mounting table or the optical system when the output shaft rotates in the reverse direction. a rotary second transmission mechanism that moves back at a higher speed than the set speed; one rotating body of the first transmission mechanism is mounted on the shaft via an electromagnetic clutch; A feature is that one of the rotating bodies is mounted on an axis via a one-way clutch that releases power transmission when the electromagnetic clutch is engaged.

(Function) Thus, by simply controlling one electromagnetic clutch in the forward/reverse transmission system, the document table or the optical system can be moved forward at a set speed or backward at a higher speed than the set speed. I can do it.

(Embodiment) Hereinafter, an embodiment of the present invention will be described based on the drawings. FIG. 1 shows an optical system moving device A, and FIG. 2 is a schematic diagram of an electrophotographic copying machine to which the optical system moving device A is applied. This copying machine has a photosensitive drum 1 having a photoreceptor on its outer peripheral surface built into the main body 2 of the copying machine, and a charging device 3 and an exposure device for moving the optical system around the photosensitive drum 1. 4. The developing device 5, the transfer device 6, the copy paper separating device 7, the static eliminator 8, and the cleaning device 9 are arranged in this order in the rotational direction of the photosensitive drum 1 (indicated by arrow Q), and
A paper feed conveyance device 10, a paper discharge conveyance device 11, a fixing device 12, and a pair of paper discharge rollers 13 are provided.

As a part of the exposure device 4 is also shown in FIG. A _first optical system A second optical system Y is provided with second and third reflecting plates 17 and 18 that reflect and project light in a direction opposite to the arrow direction P, and a second optical system Y is provided so as to be movable back and forth. A fourth reflecting plate 19 and a condensing lens 20 are arranged to project the reflected light from the photosensitive drum 1 towards the photosensitive drum 1.

In order to configure the first and second optical systems X and Y to be slidable, as shown in FIGS. 1 and 4, a pair of upper and lower rails 2 are provided with sliding members 21.
2, 23 and one guide member 24 are arranged side by side in a direction orthogonal to the arrow direction P, and members 25, 26 are slidable along the guide member 24,
Frames 27 and 28 of the first and second optical systems X and Y
The slide members 21, 2 of the rails 22, 23 are attached to one end side, and the other end sides of the frames 27, 28 are attached to the sliding members 21, 2 of the rails 22, 23.
The first and second optical systems X,
Y is movable back and forth.

Next, as shown in FIGS. 3 and 4, the scanning optical system moving device A moves a pair of upper and lower racks 29 and 30 extending in the optical system moving direction, that is, in the direction of the arrow P.
and a pinion 31 that engages the pair of racks 29, 30, and a drive device 32 for the moving mechanism B. Specifically, the lower rack 30 is fixed to the copying machine main body 2, and , the upper rack 29 is connected to the frame 27 of the first optical system
A support member 33 is connected to the frame 28 of the second optical system Y, and the drive device 32 is attached to the support member 33.
The pinion 31 is fixed to a shaft 34 on the output side of the reciprocating mechanism B (which is the input shaft to the reciprocating mechanism B).

As shown in FIGS. 5A, 5B, and 5C, when the pinion 31 is rotated forward and backward, the pinion 31 rolls on the lower rack 30, and the pinion 31 The connected second optical system Y also moves in synchronization with the pinion 31, and
Along with this rolling movement of the pinion 31, the upper rack 29 and the first optical system X connected thereto reciprocate at twice the speed in the same direction as the second optical system Y. A scanning optical system is configured to keep the optical path length up to the photosensitive drum 1 constant.

Next, the drive device 3 for the reciprocating mechanism B
2, as shown in FIG. 1 and FIGS. 3 and 4, a pair of brackets 35a and 35b are provided upright on the support member 33, and one bracket 35a has a setting that can be freely switched between forward and reverse directions. At the same time, an output shaft 37 driven by the motor via a belt transmission mechanism 36 and the input shaft 34 for the reciprocating mechanism B are installed on both the brackets 35a and 35b, and the output A rotary first transmission mechanism D that reciprocates the optical systems X and Y at a set speed in a scanning process in which the shaft 37 is rotated in the forward direction, and a rotary first transmission mechanism D that reciprocates the optical systems X and Y at the set speed in a return process in which the output shaft 37 is rotated in the reverse direction. A second rotary transmission mechanism E for backward movement at a higher speed is installed across the output shaft 37 and the input shaft 34.

Specifically, the first transmission mechanism D consists of a pair of reduction gears G ₁ and G ₂ , in which the gear G ₁ with a small number of teeth is fixed to the output shaft 37, and the gear G ₂ with a large number of teeth is connected to an electromagnetic clutch C _{1 .} The input shaft 34 is mounted on the input shaft 34 via the input shaft 34.

The second transmission mechanism E includes a pair of increasing/decreasing gears G ₃ ,
_{The second} transmission mechanism E is connected to the second transmission mechanism E through a one-way clutch C, which consists of four pairs of gears G and which fixes a gear _G3 with a large number of teeth to the output shaft 37, and releases power transmission when the electromagnetic clutch _C1 is engaged. A gear G ₄ having small teeth is mounted on the input shaft 34 .

Thus, in the scanning process, the motor M is driven to rotate in the forward direction, and in conjunction with this, the electromagnetic clutch _C1 is excited, and the rotational power of the motor M is transmitted to the pinion 31 via the gears _G1 and _G2 . Accordingly, the first and second optical systems X and Y can be moved forward at a set speed in the direction opposite to the arrow direction P at a speed ratio of 2:1, and in the return process, the electromagnetic clutch C ₁ By demagnetizing and driving the motor M in reverse rotation to drive the pinion 31 via the gears _G3 and _G4 , the first and second optical systems X,
This allows Y to move backward in the direction of the arrow P.

The above-mentioned scanning process is an exposure process, and the completion of this exposure process is detected and the electromagnetic clutch is activated.
_C1 is demagnetized, and the drive of the motor M is stopped upon detecting the completion of copying including multiple copying, that is, the completion of the return process. It is also possible to use a scanning process for the entire copyable range, and to demagnetize the electromagnetic clutch _C1 based on the completion of this process.

Incidentally, the gear G ₁ and G ₂ ratio of the first transmission mechanism D is
38:94, and the gear of the second transmission mechanism E
If the ratio of G ₃ and G ₄ is set to 70:62, the reciprocating speed will be 2.8 times the reciprocating speed, and if the rotation speed of motor M is increased by 25% during the reciprocating operation, it will become 3.5 times the reciprocating speed. The gear ratio does not matter as long as it is within a range faster than the reciprocating speed.

Incidentally, as objects to be driven by the drive device 32,
Although the reciprocating mechanism B having a rack and pinion structure is illustrated, the conventionally known reciprocating mechanism B shown in FIG.
Of course, it would be a good idea to implement it targeting

Further, in the drive device 32, the small tooth gear _G1 of the first transmission mechanism D may be mounted on the output shaft 37 via the electromagnetic clutch _C1 , or,
The gear G ₃ with a large number of teeth of the second transmission mechanism E may be mounted on the output shaft 37 via a one-way clutch C, or the gear G ₁ with a small number of teeth of the first transmission mechanism D may be mounted on the output shaft 37 via a one-way clutch C. Output shaft 3 through electromagnetic clutch C ₁
7, and the gear _G3 having a large number of teeth of the second transmission mechanism E may be mounted on the output shaft 37 via a one-way clutch C.

Further, the transmission mechanisms D and E can be changed to one in which an endless belt is wound around a pair of pulleys, and in the present invention, these pulleys, gears, etc. are referred to as rotating bodies.

Furthermore, in the present invention, the driving device 32 for the optical systems X and _Y of the copying machine has been described, but as shown in _FIG . Alternatively, if the document reading device G or the copying machine has a movable document table, the document table may be used as a driving object.

(Effects of the Invention) As explained above, according to the drive device for the original placing table or optical system of the present invention, only one electromagnetic clutch, which is more expensive than the conventional drive device, is required. The control system for can be made extremely simple, and as a result,
This made it possible to significantly reduce the cost of the drive device.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a perspective view of a scanning optical system moving device shown together with a part of an exposure device, FIG. Fig. 3 is a configuration diagram of a drive device for the optical system reciprocating mechanism, Fig. 4 is a - line view of Fig. 3, Fig. 5 A, B, and C are movement configuration diagrams of the rack, and Fig. 6 is a configuration diagram for reading originals and FIG. 2 is a conceptual diagram of an output device. FIG. 7 is a movement diagram of a conventional optical system moving device. 34...Input shaft, 37...Output shaft, B...Reciprocating mechanism, C...One-way clutch, _C1 ...Electromagnetic clutch, D...First transmission mechanism, E...Second transmission mechanism, X ...first optical system, Y...second optical system.

Claims (1)

[Scope of utility model registration request] The document mounting table is a drive device for reciprocating the optical system as the output shaft rotates forward and backward, and the document mounting table or the optical system is moved between the input shaft and the output shaft for the reciprocating mechanism, a rotary first transmission mechanism that moves the document placing table or the optical system forward at a set speed when the output shaft rotates forward; and a rotary first transmission mechanism that moves the document placing table or the optical system forward at a higher speed than the set speed when the output shaft rotates in the reverse direction. a rotary second transmission mechanism for moving the first transmission mechanism, and one rotating body of the first transmission mechanism is mounted on the axis via an electromagnetic clutch, and one rotating body of the second transmission mechanism is connected to the electromagnetic clutch. 1. A drive device for a document placing table or an optical system, characterized in that it is mounted on a shaft via a one-way clutch that releases power transmission when the clutch is engaged.