JPS607773B2 - Electrophotocopy machine scanning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scanning device for an electrophotographic copying machine.

Normally, the following steps, ie, time, are required to obtain a copy using an electrophotographic copying machine.

○} Time to align the originals on the document table.

‘2’ Time to set the required number of copies and press the copy button.

'31 The time it takes for the copying machine to perform the exposure process. [41
The time taken from the end of a series of copying cycles until the copy paper is ejected from the machine. (5) Time to take out and align copy sheets ejected outside the machine.

'61 Time to remove the original after exposure or replace it with the next original if there are multiple originals.

In this way, since a lot of time is required, the time required for the copying operation becomes longer.

Therefore, in recent years, in order to shorten copying work time, the above-mentioned {1
Various means have been proposed to shorten the time for ', '3}, [4}, and ■.

For example, in order to shorten the time it takes for a copying machine to perform the exposure process, a method has been proposed to shorten the wasted time by increasing the return scanning speed of the moving optical system of the scanning device. .

However, with this method, not only is a large acceleration applied to the moving optical system during the adjustment of the return scan, but also the vibration is propagated to the copying machine body, adversely affecting the copied image. As a result, the entire copying machine body becomes heavy and expensive.

A conventional example will be explained below with reference to FIG.

A scanning device a is provided at the bottom of the platen, and the scanning device a includes first and second reflecting means 2 and 3 serving as a moving optical system, a reflecting lens 4, a third reflecting means 5, and an exposure lamp (not shown). , photoreceptor drum I0' projects an image of the original document.

A charging means A, an exposure slit plate B, a developing means C, a transfer means D, and a cleaning means E are arranged around the photosensitive drum 10.

Reference numeral 15 denotes a copying machine (transfer material), which feeds the material through a supply roller 16 and a synchronized roller 7 to a transfer means D, transfers it, sends it to a fixing means F, fixes it, and discharges it.

In the scanning device a having such a structure, when the return scanning speed is increased in order to shorten the time for return scanning, the displacement of the first reflecting means 2 with respect to time is as shown in FIG. 2, as shown in line b during scanning. During the return scan, the speed becomes more gradual as shown in line c, and the speed during the return scan becomes significantly farther than the speed during the scan, so the acceleration/deceleration during the return scan becomes larger, resulting in the above-mentioned problem. will occur.

In addition, even if the process speed of the copying machine itself is increased, such as by increasing the return scanning speed of the moving optical system, as mentioned above, it will take the minimum amount of time to remove the cover layer and remove the document, so that copying will be faster. It is not possible to increase the work speed beyond a certain value. The present invention was made in view of the above circumstances, and its purpose is to provide an electrophotographic copying machine that can increase the scanning speed without increasing the rigidity of the copying machine body, and can significantly increase the copying speed. It is an object of the present invention to provide a scanning device for the invention.

Embodiments of the present invention will be described below with reference to FIG. 3 and subsequent figures.

The copying machine main body 201 has first and second document stands 21, 22 (
(hereinafter referred to as platens) are arranged in parallel, and below the first and second platens 21 and 22 are first and second moving optical systems 23,
24 are provided respectively. The first moving optical system 23 includes an illumination means 31 for exposure, a first reflection means 32, and a second reflection means 33, and the second movement optical system 24 includes an illumination means 51 for exposure and a first reflection means 52. and a second reflecting means 53, and the first and second moving optical systems 23 and 24 are configured to reciprocate symmetrically to scan the first and second platens 21 and 22, respectively. It has been done. That is, when the opposing approach position (solid line position in Figure 3) is reached, the first moving optical system 2
3 is the scan start position and the second moving optical system 24 is the scan end position, and when the opposite separation position (the imaginary line position in FIG. 3) is reached, the first moving optical system 23 is the scan end position and the second moving optical system 24 is the scan end position.
becomes the scanning start position. In other words, the first moving optical system 23
When moving in the direction of arrow b, the second moving optical system 24 enters a scanning state, and when moving in the direction of arrow c, it enters a return scanning state. In addition, each of the first and second reflecting means 32, 52
, 33, 53 reciprocate in parallel along the first and second platens 21, 22, and the second reflecting means 33, 53 move at half the speed of movement of the first reflecting means 32, 52. It is supposed to be done.

34 is a lens provided at an intermediate position between the first and second moving optical systems 23 and 24, and a pair of third lenses are provided on both sides of the lens 34.
Reflection means 35 and 54 are provided opposite each other.

36 is a fourth reflecting means provided between the pair of third reflecting means 35 and 54, and the fourth reflecting means 36 is connected to the first moving optical system 2.
The first position 4 reflects the reflected light from the second moving optical system 24 toward the photoconductor drum 37 (solid line position in FIG. 3), and the second position reflects the reflected light from the second moving optical system 24 toward the photoconductor drum 37 (
It is freely rotatable to the imaginary line position in Fig. 3).

Around the photosensitive drum 37, there are a charging means 39, a slit plate 38, a developing means 40, a transferring means 41, and a peeling means 42.
, cleaning means 47 are provided.

44 is copy paper (transfer material), which is fed to the transfer means 41 by a paper feed roller 45.

43 is a fixing device, and 46 is a discharge tray.

Next, the main parts of the present invention will be specifically explained with reference to FIG. Reference numeral 65 denotes a pair of rails arranged in parallel across the lower positions of the first and second platens 21 and 22. The first reflecting means 32 and the illuminating means 31 are located below the first platen 21 of the rails 65.
a first carriage 61 comprising: and a second reflecting means 3;
A second carriage 67 equipped with a first reflection means 52 and an illumination means 51 is movably constructed via bearings, and a third carriage 75 equipped with a first reflection means 52 and an illumination means 51 is disposed below the second platen 22. A fourth carriage 76 equipped with the second reflecting means 55 is movably provided via a bearing.

Reference numeral 85 denotes a main motor, which transmits power to the photosensitive drum 37 via a first transmission means 70, and a main motor provided on the first and second shafts 74, 79 via a second transmission means 84 such as a chain. The power is transmitted to the first and second clutches 82 and 83, respectively.

The first and second shafts 74 and 79 are provided with gears 80 and 81 that mesh with each other.
79 are adapted to be driven in mutually opposite directions. The first shaft 74 is provided with a large diameter pulley 90 and a small diameter pulley 71, and the first and second cables 98, 99 wound around the respective pulleys 90, 71 are connected to the large diameter idler pulley 72 and the small diameter idler pulley 73. The first strands 98 and the second strands 99 are respectively wound around the first carriage 61 and the second carriage 67.

The second shaft 79 has a large pulley 77 and a small diameter pulley 78.
A third,
The fourth strands 62 and 63 are wound around a large idler pulley 64 and a small idler pulley 69, respectively, and the third strand 62 is wound around the third carriage 75, and the fourth strand 63 is wound around the fourth idler pulley 69.
They are each attached to a carriage 76.

Further, the fourth reflecting means 36 is rotated between the first position and the second position by the cylinder 86.

Next, the operation will be explained. From the illustrated state, the first clutch 82
When the second clutch 83 is disengaged and the main motor 85 is driven, the photosensitive drum 37 rotates in the direction of the arrow d.

At this time, the rotational speed of the photosensitive drum 37 is set in advance to be the same circumferential speed as the speed of the first and second moving optical systems 23 and 24, that is, the scanning speed. On the other hand, the first shaft 74 is rotated clockwise via the first clutch 82, and the second shaft 79 is rotated counterclockwise by the pair of gears 80 and 81.

For this purpose, the first and second carriages 61 and 67 move to the right along the seal 65, and the third and fourth carriages 75
, 76 move to the left along the rail 65.

That is, the first moving optical system 23 moves in the direction of arrow b to scan the document on the first platen 21, and the second moving optical system 24
moves in the direction of arrow c to scan the original on the second platen 22. At this time, the fourth reflecting means 36 is rotated to the first position by the cylinder 86, so the first moving optical system 23
Since only the reflected light from the slit plate 38 is projected onto the photosensitive drum 37, the first moving optical system 23 is in a scanning state, and the second moving optical system 24 is in a return scanning state.

Then, when the first and second moving optical systems 23 and 24 are in a position where they are opposed to each other and are separated from each other (the imaginary line position in FIG. 3), the first clutch 82 is disengaged, the second clutch 83 is engaged, and the cylinder 86 The fourth reflecting means 36 is set to the second position.

In this way, the first shaft 74 rotates counterclockwise and the second shaft 79 rotates clockwise, so that the first and second carriages 61 and 67 are rotated to the left, and the third and fourth carriages 7
5,76 moves to the right.

That is, the first moving optical system 23 moves to the left, and the second moving optical system 24 moves to the right to scan the originals on the first and second platens 21 and 22.

However, at this time, since the fourth reflecting means 36' is at the second position (the imaginary line position in FIG. 3), only the reflected light from the second moving optical system 24 passes through the slit plate 38 to the photosensitive drum 37.
projected on top. Therefore, the second moving optical system 24 is in the scanning state, and the first moving optical system 23 is in the return scanning state.

That is, the displacements of the first reflecting means 32 of the first moving optical system 23 and the first reflecting means 52 of the second moving optical system 24 with respect to time are as shown in the table of FIG. 5, and when one is in scanning, the other is This is a return scan.

In FIG. 5, A indicates the displacement of the first reflecting means 32 of the first moving optical system 23, and the opening indicates the displacement of the first reflecting means 52 of the second moving optical system 24. The solid line part is scanning, and the dotted line part is scanning. Indicates a return scan. Note that the circumferential speed of the photosensitive drum 37 and the first
Since the moving speeds (scanning speeds) of the second moving optical systems 23 and 24 are the same, the flow image is correctly formed on the photosensitive drum 37.

As described above, the first and second moving optical systems 23 and 24
Because they move symmetrically (opposing separation action, opposing approach action), the accelerations of the first and second moving optical systems 23 and 24 can be mutually canceled out, and even when scanning and returning at high speeds, copying is not possible. The propagation of vibration to the machine body is limited to a maximum of 4 degrees, making it possible to obtain accurate copied images without increasing the rigidity.

Furthermore, since one moving optical system 23 scans while the other moving optical system 24 scans, the wasted time of the scanning device can be effectively utilized, and compared to a conventional scanning device with the same scanning speed, the scanning speed can be reduced within the same time. Approximately twice as many copies can be obtained.
In other words, since it has the copying performance of two machines, the copying speed can be significantly improved. In addition, although it has the copying performance of two machines, on the other hand, it is structurally simple and cost-effective because only one new moving optical system is required.

Incidentally, as shown in FIG. 6, lenses 34 may be provided in the first and second moving optical systems 23 and 24, respectively, and as shown in FIG.
may be provided.

In this way, the first platen 21 and the second platen 22
You can arbitrarily select the copy magnification of each of the above originals. In this case, it is necessary to make the scanning speeds of the first and second moving optical systems 23 and 24 different. Further, in the embodiment, the image to be projected was selected by switching the fourth reflecting means 36 to the first and second positions, but the reflecting means was provided before entering the lens 34 to select the image to be projected. Alternatively, a light shielding means may be provided in the middle of the optical path and the light shielding means may be operated alternately to select the image to be projected.

In addition, as shown in FIG. 3, the first and second moving optical systems 23, 2
4 separate drive sources, return springs 107, 108
It may also be configured to perform a return scan. With this configuration, the displacements of the first reflecting means 32, 52 of the first and second moving optical systems 23, 24 with respect to time can be set as shown in the table of FIG.

Since the present invention is configured as described above, the first and second moving optical systems 23 and 24 synchronize with each other to perform opposing approach and separation operations, so that the acceleration of the first and second moving optical systems 23 and 24 can be reduced. They can cancel each other out, and even when scanning and returning at high speeds, vibrations are only transmitted to the copying machine body for a maximum of 4.5 seconds, allowing the scanning speed to be increased without increasing the rigidity of the copying machine body. . Also, when the first and second moving optical systems 23 and 24 move toward each other, one moving optical system scans and the other does not scan, and when they move away from each other, the other moving optical system scans. Since one of the moving optical systems does not scan, the wasted time of the scanning device can be used effectively, and it is possible to obtain approximately twice as many copies in the same time compared to a conventional scanning device with the same scanning speed. This can significantly improve copying speed.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional example, Fig. 2 is a table diagram showing the displacement of the first reflecting means, Fig. 3 is an explanatory diagram showing an embodiment of the present invention, Fig. 4 is a perspective view of the main part, and Fig. 5 The figure is a table showing the displacement of the first reflecting means, Figures 6 and 7 are explanatory diagrams showing different embodiments, Figure 8 is an explanatory diagram showing still different embodiments, and Figure 9 is an explanatory diagram showing a further different embodiment. FIG. 7 is a table showing the displacement of the first reflecting means. 23 and 24 are first and second moving optical systems, and 37 is a photosensitive drum. Figure 1 Figure 2 Figure 3 Figure 5 Figure 4 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] 1. The copying machine main body 20 is provided with first and second original stands 21 and 22 in parallel, and below the first and second original stands 21 and 22 is provided with an illumination means for exposure and a plurality of reflection means. The first and second moving optical systems 23 and 24 are respectively provided so as to be reciprocally movable along the first and second original tables 21 and 22 so as to synchronously approach and separate from each other. When the optical systems 23 and 24 move toward each other, one of the moving optical systems 24 and 23 scans the document on one of the document stands 22 and 21 and projects it onto the photoreceptor 37, and the moving optical systems 24 and 23 scan the document on either of the document tables 22 and 21 and project it onto the photoreceptor 37. When the moving optical system 23, 24 of the other moves in the direction of
1. A scanning device for an electrophotographic copying machine, characterized in that a document on a document 2 is scanned and projected onto a photoreceptor 37.