JPS5814351Y2 - Scanning device in electronic copying machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic copying machine capable of full size copying and reduced copying, and particularly relates to an improvement of a scanning device.

In an electronic copying machine, it would be convenient if it could not only make a copy of the same size as the original surface (hereinafter referred to as a same-size copy), but also make a reduced copy.

Therefore, recently, an improvement has been made so that reduction copying can be performed even by pressing a button on a device that scans the surface of the document with a slit and exposes the photoreceptor to light.

To perform this reduction copying, the lens of the optical system is moved to the exposure surface side according to the reduction ratio, the mirror that reflects the light transmitted through the lens is moved to the exposure surface, and the slit exposure speed is adjusted to the reduction ratio. It is necessary to speed up accordingly.

In other words, the speed of the slit scanning movement section (original table or scanning mirror) must be different during full-size copying and variable-magnification copying.

For this purpose, a scanning device having a speed change function is provided, but conventionally it is intercepted from two sets of electromagnetic clutches and operated alternately.

However, this type of mechanism has the disadvantage of increasing costs.

Alternative mechanisms have also been used, but they all have disadvantages such as being complex and having poor stability.

The present invention has been developed based on the above circumstances, and its purpose is to provide a scanning device for an electronic copying machine that has a relatively simple mechanism, can reliably change speeds, and has little impact on cost. That is.

An embodiment of the present invention will be applied to an electronic copying machine capable of full size copying and reduced copying, and will be described below with reference to the drawings.

FIG. 1 shows the main parts of an electronic copying machine, and reference numeral 1 denotes a document table (not shown) fixed to the upper part of the main body of the electronic copying machine.

This is a document placed on the document table 1 of a double-barber with the document surface 2a facing down.

Further, an optical system 3 is provided below the document table 1.

That is, 4 is a light source that emits light onto the original 2, and 5 is a first mirror that receives light reflected from the original 2.

Furthermore, 6 and 7 are the second mirrors that receive the light reflected by the first mirror 5. A third mirror, 8, is a lens provided on the optical axis P to condense light.

9 is a fourth mirror that reflects the light transmitted through the lens 8 onto the exposure surface 10a formed on the peripheral wall of the photoreceptor 10 to form an original image.

Further, the light source 4 and the first mirror 5 are connected to the first carriage 11, and the second mirror 5 is connected to the first carriage 11. The third mirrors 6.7 are each fixed to the second carriage 12.

The first carriage 11 is a scanning device 1 which will be described later.
3, and is reciprocally movable along the document table 1. The second carriages 11 and 12 are connected by a coupling mechanism (not shown), and the second carriage 12 is adjusted to always move at 1/2 the speed of the first carriage 11.

Therefore, even if these carriages 11 and 12 move, the optical path length from the document surface 2a to the lens 8 is always constant.

(This is because the first carriage 11
If the second carriage 12 moves in, the movement of the second carriage 12 is 1/23 mm.

Therefore, the first mirror 5 and the second mirror 6 are 1/2
S11t7n interval widens, third mirror I and lens 8
1/2 The Sl depth interval becomes narrower.

Eventually, the amount of movement of each carriage 11, 12 cancels out, and the first
The optical path length from mirror 5 to lens 8 remains unchanged.

The scanning device 13 will be explained below.

That is, this is as shown in Figs. 2 to 4, and 14 shown in Figs.
R).

This drive 5PR14 is always rotated at a constant rotational speed in the direction of the solid line arrow in the figure by the drive source, and a drive chino 15 is connected to this drive 5PR14.

The driving chino 15 includes a plurality of intermediate 5PR15a...
The input 5PR16h and the variable power 5PR17 having the same number of teeth engage with each other, so that the chino 15 runs endlessly.

The input 5PR16 is fitted on the first rotating shaft 18, and the variable power 5PRI7 is fitted on the second rotating shaft 20.

These first. The second rotating shafts 18, 20 are mounted on mounting plates 21 that are spaced apart and facing each other, as shown in FIG.

21 via bosses 22 . . . rotatably.

In addition, the first rotating shaft 18 is connected to the above-mentioned implant via the first one-way clutch 23a which is a clutch portion.
SPRl6, the first one with the same number of teeth as 5PRI7 for variable magnification
A driven 5PR24 is fitted.

This first driven 5PR24 and the above implant) SPRl
An intermediate boss 25 is interposed and fitted between it and b.

Further, a second driven shaft 5PR26 having a larger number of teeth than the first driven shaft 5PR24 is connected to the second rotating shaft 20 via a second one-way clutch 23b which is a clutch section.
are mated.

An intermediate boss 27 is interposed and fitted between the second driven 5PR26 and the magnification variable 5PR17, and a switching mechanism 28 biases this and the magnification variable 5PRIγ.

That is, the spring clutch 28a is integrally fitted to the variable power 5PR 17 and the intermediate boss 27, and
A ratchet gear 28 is fitted into this.

Furthermore, as shown in FIG. 4, a magnet 29 is disposed near the ratchet gear 2B and pivots one end of the spot pole 30 to the operating rod 29a via a pin.

The spot pole 30 is swingably supported around a pin 30a located approximately in the middle thereof, and has a return spring 31 stretched in the direction opposite to the biasing direction of the operating rod 29a.

Further, the other end of the spot pole 30 is formed into a claw shape,
When the magnet 29 is demagnetized, it is locked to the ratchet gear 28 by the biasing force of the return spring 31.

Therefore, the spot pawl 30 is attached to the ratchet gear 28.
When not engaged, the rotation of the variable power 5PR 17 is transmitted to the intermediate boss 27 via the spring clutch 28a, and the second rotating shaft 20 further rotates.

However, when the spot pawl 30 is engaged with the ratchet gear 28, even if the variable power 5PR17 rotates, the spring clutch 28a is disengaged, so that the second rotating shaft 20 does not rotate and the variable power 5PR17 rotates fully. It has become.

On the other hand, as shown in Figure 2. second driven 5PR24,
25 is connected to a gear shifting cheno 32, which is engaged with an intermediate 5PR33, 5PR34a and Th as driving means for the mirror back clutch 34, and 5PR35a of the mirror forward clutch 35.

A wire pulley 36 is also fitted to the mirror forward clutch 34, and the first carriage 11 is connected to the wire pulley 36.
A driving wire 37 for attaching the wire is hung.

When a copying button (not shown) is pressed, the mirror forward clutch 35 transmits the rotational force of the 5PR 35a to the wire pulley 36 to move the first carriage 11 forward in the direction of the dashed-dotted line arrow in the figure, completing all copying operations. When the clutch is engaged, the 5PR35a is rotated idly.

Further, the mirror back clutch 34 is engaged when the first carriage 11 moves forward and reaches a predetermined position, and rotates the 5PR 34a in the opposite direction to the previous direction, thereby moving the gear changing chino 32 in the direction opposite to the arrow shown by the broken line. It is designed to run.

Therefore, at this time, the driving wire 37 moves back in the opposite direction of the dashed line arrow, and the first. Second driven 5PR
24 and 26 are the first and second one-way clutches 23a
, 23b, each rotates idly.

- In the vicinity of the force photoreceptor 10, well-known electronic copying machine components such as a developer, a transfer charger, a scraper, a cleaner, a copy paper feeder, a conveyance device, a fixing device, etc. (all not shown) are arranged. has been done.

The operation of the above embodiment will be explained below.

First, to explain about 1:1 copying, place the original 2 on the document table 1, and set the magnification conversion dial (not shown) to ``1:1''.
, then press the copy button.

Then, the lens 8 and the fourth mirror 9 are positioned as shown by solid lines in FIG. 1, the magnet 29 is demagnetized, and the spot hole 30 engages with the ratchet 28.

Furthermore, the drive 5PRI4 rotates to run the drive chino 15, and the input 5PRI 6 $- and the variable magnification 5PR
17 is driven to rotate.

However, due to the ratchet gear 28, the variable power 5PR 17 rotates idly with respect to the second rotating shaft 20, and the first driven 5PR
24 is rotationally driven via the first rotating shaft 18.

Therefore, the speed change cheno 32 is run at a speed based on the number of teeth of the first driven 5PR24, and the second driven 5PR26 is
is simply a driven rotation.

Shifting Cheno 320 running is Miller Ford clutch 35
The wire pulley 36 is driven through the driving wire 3γ to run.

Therefore, the first carriage 11 is displaced forward along the document table 1 at the speed ν, and the second carriage 12 is displaced at the speed (
1/2v) to scan the document surface 2a and form a projected image on the photoreceptor 10.

The photoreceptor 10 rotates at a circumferential speed ν and is charged by a charger to form a latent image pattern of the projected image.

This image is then replaced with a copy image of copy paper by the predetermined actions of each component below the developing device.

Further, when the first carriage 11 reaches the position where it finishes scanning the document surface 2a, the mirror back clutch 34 is activated to cause the speed change chino 32 to travel in the opposite direction, causing the first carriage 11 to move back and return to the starting position. be able to.

A case in which reduction copying is performed at all times will be explained.

That is, the original 2 is placed on the original table 1, the magnification conversion dial is set to "reduction", and the copy button is pressed.

Then, the lens 8 and the fourth mirror 9 are displaced to the positions shown by two-dot chain lines to correct the optical path length, and the solenoid 29 is energized to separate the spot pole 30 from the ratchet gear 28.

Therefore, the input 5PR16, which rotates as the first drive chain 15 runs, transmits rotational force to the first rotation shaft 18, and the variable power 5PR17 transmits rotational force to the second rotation shaft 20 via the spring clutch 28a and the intermediate boss 21. Communicate.

That is, the first. The second driven 5PR24°26 rotates, but the number of teeth of the second driven 5PR26 is the same as that of the first driven 5PR2.
Since the number of teeth is greater than 4, the first driven 5PR24 rotates at an increased speed equal to the number of teeth of the second driven SPR/the number of teeth of the first driven SPR. : Rotates idly against the opponent.

Therefore, the speed change cheno 32 is connected to the second driven 5PR26.
It travels at a speed based on the number of teeth, which is faster than when copying at the same size as described above.

This movement causes the driving wire 3T to run via the Miller-Ford clutch 35, and the first carriage 11 is eventually moved forward at a speed corresponding to the reduction ratio.

Then, a reduced copy image is obtained on the copy paper by the same operation as in the above-mentioned same-size copying.

Among them, in the above embodiment, the light source 4, the first mirror 5a,
Although the first carriage 11 is used as a slit scanning moving unit and is moved at variable speeds, the present invention is not limited to this, and the optical system 3 may be fixed and the document table 1 may be moved at variable speeds.

Furthermore, although the button in the above embodiment is used to perform full size copying and reduced copying, the invention is not limited to this, and enlarged copying may be performed by slowing down the speed of the slit scanning moving section. In short, it is sufficient if the slit scanning moving section can be driven at variable speeds.

As explained above, with the present invention, the variable speed chino is driven at a speed based on the number of teeth of the first driven sprocket during full-scale copying, and at a speed based on the second driven sprocket during variable-magnification copying. Since the slit scanning moving part is moved back and forth by traveling and moving the slit scanning moving part forward, and the speed changing chino is driven and traveling by the driving means to move the slit scanning moving part backward, the slit scanning moving part can be driven back and forth at variable speeds as necessary. be able to.

Therefore, the present invention has the advantage of being low cost, having a highly stable speed change function, and enabling variable size copying.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a schematic front view of the main parts of an electronic copying machine, Fig. 2 is a schematic front view of the scanning device, and Fig. 3 is a schematic front view of the main parts of the scanning device. The vertical sectional view and FIG. 4 are front views of the switching mechanism. 15... Drive chino, 18... First rotating shaft, 16
... Input sprocket, 20... Second rotating shaft, 17... Sprocket for variable power, 28... Switching mechanism, 23a... Clutch section (first one-way clutch), 24... First driven sprocket, 23b...
・Clutch part (second one-way clutch), 26...
- Second driven sprocket, 4... Slit scanning moving unit (light source), 5... Slit scanning moving unit (first mirror), 11... Slit scanning moving unit (first carriage), 32 . . . Speed change cheno, 34a . . . Drive means (sprocket).

Claims (1)

[Scope of utility model registration request] In an apparatus for making the speed of a reciprocating slit scanning moving part different between when copying at the same magnification and when copying at variable magnification, there is provided a drive chino that travels at a constant speed, and a first chino that is engaged with the drive chino and that is engaged with the drive chino.
An input sprocket button fitted to the rotating shaft of a switching mechanism that fully rotates the magnification sprocket and transmits the rotational force of the magnification sprocket to a second rotating shaft during variable-magnification copying; driven sprocket button and the second
a second driven sprocket that is fitted onto the rotating shaft of the second driven sprocket through a clutch portion and has a different number of teeth from the first driven sprocket; A speed change cheno to which the slit scanning moving part is attached, and a drive means for driving the speed change chino in a direction opposite to the driving direction transmitted from the first or second driven sprocket, The chino is driven at a speed based on the number of teeth of the first driven sprocket during full-scale copying, and at a speed based on the second driven sprocket during variable-magnification copying to move the slit scanning moving unit forward, and 1. A scanning device for use in an electronic copying machine, characterized in that a speed changing chino is driven and traveled by a driving means to cause a slit scanning moving section to move backward.