JPH0121488B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copying apparatus in which all copying operations are performed on the front side.

General-purpose copying machines can be roughly classified into the following three types with respect to their original setting position, copy paper setting position, and ejection position.

(b) When the original and copy paper are set and the ejection position are both based on the center (b) When the original is set on the front side (operating side of the copying machine), and when the copy paper is set and ejected on the back side (c) the original The set position and copy paper ejection position are based on the front side, and the copy paper set position is based on the back side.To explain these in more detail with reference to Figs. 1 to 3, which show the principles, Fig. 1 shows. In the type of copying machine shown in (a) above, the document loading position, copying paper loading position, and ejection position are all based on the center, so the lens only needs to be moved in the optical path direction when changing the magnification, so the optical system is The mechanism is single-sided, but when setting a double-sided original, it must be aligned with the mark on the loading table each time, making accurate positioning troublesome. The operation was complicated as it had to be moved from the beginning.

In the copying machine of type (B) above shown in Figure 2, the original is set with the front reference, but the copy paper is set and ejected with the back reference, and even when changing the magnification, the copy paper is set in the back reference position. The lens is moved in the direction of the optical path and in the direction perpendicular to the direction of the optical path, and when setting a document, the front side is used as a reference regardless of its size, so it can be easily and accurately set, but copy paper The setting and ejecting position is located at the back and is far from the operating position, which has the disadvantage of making setting and removing difficult.

The copying machine of type (c) above shown in Fig. 3 has a second
It is almost the same as the type (b) in the figure, but
Immediately before the copy is ejected, the copy that is progressing on the back side is moved diagonally in parallel to align the copies of all sizes to the front side. This is good for setting the original and handling the ejected copy, but it is difficult to copy. The disadvantage is that the paper is set at the back, making it difficult to operate.

In addition, variable-magnification copying machines are generally operated by full-time operators at copy centers and the like, and the operations are often very complicated. In recent years, changes in document management laws and other market needs have led to decentralized management of variable-magnification copiers, but it is realistically difficult to assign full-time operators to each department, so this type of copier Its functions were not fully utilized, and malfunctions occurred due to incorrect operation.

The present invention aims to improve the above-mentioned drawbacks of general-purpose copying machines and provide a copying machine with excellent accuracy and operability. The present invention is intended to provide a device that allows even people, such as office workers, who are inexperienced in operating copying machines, to fully utilize the variable magnification function.

Hereinafter, the details of the present invention will be explained based on the drawings.

FIG. 4 shows an example of a copying machine to which the present invention is applied. On the outer periphery of the photoreceptor drum 10, along the rotation direction thereof, a charging charger 11, an image erase lamp 12, an exposure section 13, a developing device 14 are arranged. , the transfer section 15, the cleaning device 16, and the static elimination charger 17 are arranged in the approximate order of the Carlson process.

Regarding the optical system, this figure shows a variable magnification projection device. During the same-size copying, the first mirror unit 21 moves at a speed equal to the circumferential speed v ₀ of the photosensitive drum 10. Also, during variable magnification copying, the third and fourth mirror pairs 23 and 24 are displaced in the direction of the bisector of the angle formed by the optical path, and the lens 25 is displaced in the direction of the optical path, depending on the magnification. It is well known that the 1-mirror unit 21 moves at a speed of v=1/mv ₀ (m: variable magnification) and projects an optical image at a specified magnification onto the photoreceptor. Lens movement in the present invention will be explained in detail later. This magnification change is operated by pressing a magnification designation button (not shown), for example, and simultaneously with this operation, a signal corresponding to the magnification is output from a magnification designation signal generator.

A plate 3 is disposed on the upper surface of the copying machine body to hold down the original placed on the platen 5, and the plate 3 is further provided with an original size detecting device 31 consisting of a photoelectric detection element. The size is converted into an electrical signal by a document size signal generator. The document size detection means is not limited to the above-mentioned device, but may be detected by, for example, a light emitting diode and a light receiving element disposed in the copying machine, or a device such as the one shown in FIG. If the copying machine is equipped with an automatic document feeder, it can be detected by the document supply section as described later, and there is also a manual means that reads the document size from the scale on the document placement section and presses the corresponding document size button. It can also be achieved by taking

FIG. 5 shows an example of an automatic document feeder equipped with the document size detection means described above.
The automatic document feeder 3, which corresponds to the document holding plate 3 in the figure, includes a document insertion table 32, a belt 33, a belt drive pulley 34, gates 35 and 36, and a pressure roller 3.
It consists of 7, etc. In other words, the document insertion table 3
When the document 2 on top of the document 2 passes through the entrance guide plate 32a and enters the gap between the belt drive pulley 34 and the entrance pressure roller 37, it hits the entrance gate 35 and stops for a moment. When a document feeding signal is input and the pressure roller energizing and entrance gate release solenoid 35a is activated, the entrance gate 35 is retracted, and the pressure roller 37 comes into pressure contact with the pulley 34 to feed the document 2. The exit gate pressurizing solenoid 36a is activated while the document is being transported, and the exit gate 36 is brought into pressure contact with the platen 1, thereby stopping and positioning the transported document 2. A document size detection device 31 is provided in the document conveyance path described above, and in the figure, the document size can be detected at a point after passing through an entrance gate 35. This device 3
1 can be a photoelectric reflection type or a transmission type, or a known type such as a micro switch, and a plurality of them can be arranged in a direction perpendicular to the direction of document movement to detect the time when the detection device is turned ON while the document is being moved. This method also detects the document size.

Note that in FIG. 5, reference numeral 38 indicates a roller that applies pressure from the back side to increase the conveyance force of the belt 33 during document ejection, and 39 indicates an ejection roller.

Returning to FIG. 4 again, the main body of the copying machine is loaded with a plurality of paper feed trays or paper feed cassettes 41, 41' for storing copy paper of different sizes, and copy paper of different sizes are individually provided. The paper is fed by paper feed rollers 42, 42'. The paper feed rollers 42, 42' are driven by operating a copy paper size selection device (not shown), for example, a size selection button, and by operating the above-mentioned document size detection signal generation device and magnification designation signal generation device. A copy sheet of a suitable size is automatically selected based on the signal. Then, the required paper feed rollers 42, 4
When 2' is selected, the size of the corresponding copy paper is extracted as an electrical signal by the copy paper size signal generator.

Note that the copying machine to which the present invention is applied is not limited to the one shown in FIG. 4, and may be a single-size paper feeding type copying machine that uses copying paper of a desired size by replacing it as appropriate.

Next, to make all copy operations based on the front side,
Figures 6 to 8 explain where the lens should be positioned depending on the original size, copy paper size, and magnification, and Figures 9 to 12 explain the flow of automatic operation. This is based on the following.

(B) At the same size (Fig. 6) Both the original and copy paper have the maximum width size w ₀
, the lens is in the center.

When setting both an original and copy paper of size w with the front side as a reference, the lens only needs to be moved by w ₀ -w/2 . . . in the Y direction (direction perpendicular to the optical path).

From FIG. 9, in the case of a single-size paper feeding type copying machine, replacing the copy paper of the desired size, and in the case of a copy machine loaded with copy paper of various sizes, selecting the copy paper of the desired size, A size signal is generated by the copy sheet size signal generator, and the control signal operates the lens moving device to move the lens by the amount described above in a direction perpendicular to the optical path.

(b) When changing magnification - Part 1 (Figure 7) When specifying the desired copy paper size and magnification.

The width size of the largest original and the largest copy paper is w ₀ ,
Assuming that the specified size of the copy paper is w and the specified magnification is m, in order to set both the original and the copy paper with the front side reference, move the lens in the X direction (optical path direction) and Y direction, respectively, x = (1/m-). 1) f (f: focal length of lens) ... y=1-m/1+m・w ₀ /2+mw ₀ -w/1+m=w ₀
/2− w/1+m . . .

As shown in Figure 7a, if the width size of the copy paper matches the size obtained by changing the size of the original with the maximum width size at the magnification factor m, then w = mw ₀ , so
From the formula, y=1-m/1+m・w ₀ /2...

For example, if maximum copy width w ₀ = 364 mm (B4), lens focal length f = 230 mm, variable magnification m = 0.816, and selected copy paper width w = 257 mm (B5), then x = (1/0.816-1)・230=51.8(mm) y=364/2-257/1+0.816=40.5(mm)

As shown in FIG. 10, when the copy paper is replaced or selected and the magnification is specified, a size signal and a magnification signal are output from each signal generator.
Both signals cause the controller to operate the lens moving device to move the lens by the amounts described above in the X and Y directions.

In addition, in the case of equal magnification, that is, when the specified magnification m is 1, the formula becomes x=0, and the formula becomes Y=
W ₀ −W/2, which is the same as the above formula.

C. When changing magnification - Part 2 (Figure 8) When specifying the original size and desired copy paper size.

Let w ₁ be the detected original size, w be the copy paper size, and w ₀ be the maximum copy width size. In order to set the original, copy paper, and eject all from the front side, move the lens in the X direction. Y
It is sufficient to move the amount of x=(w ₁ /w-1)f ... y=w ₀ /2-w ₁ w/w ₁ +w ... in each direction.

For example, maximum copy width w ₀ = 364 mm (B4), lens focal length f = 230 mm, document width size w ₁ = 297
mm (A4), copy paper width size w = 257 mm (B4), x = (297/257-1) x 230 = 35.8 (mm) y = 364/2 - 297 x 257/297 + 257 = 44.2 (mm) Become.

From Figure 11, when copy paper is replaced or selected and the original size is specified, a paper size signal and an original size signal are output from each signal generator, and based on both signals, the control device determines the position the lens should take and moves it. let

Furthermore, as shown in Fig. 12, in a copying machine loaded with copy paper of various sizes, the required copy paper size is automatically selected based on the original size signal and the magnification signal, and the lens is Move the required amount in the X and Y directions.

As described above, when the lens is moved in a direction perpendicular to the optical path, exposure unevenness may occur in the longitudinal direction of the exposure slit. This exposure unevenness is due to the lens
This occurs due to the symmetry being broken when the lens is moved due to the illumination distribution being raised at both ends and the slit width being widened at both ends in order to correct the peripheral dimming caused by the cos ⁴ theta law and the aperture efficiency of the lens. It is something.
To correct this, the slit shape can be changed in conjunction with the movement of the lens, the illumination distribution can be changed in conjunction with the movement of the lens, and the slit can be partially moved (towards the side) in the optical path with the movement of the lens. This problem can be solved using conventionally known techniques, such as cutting off the increase in illuminance by using a fixed baffle plate that fits in.

In the embodiment described above, only one lens is used, but a plurality of lenses of different sizes adapted to the magnification or copy paper size may be used interchangeably. Further, although a transfer type copying machine is described, it can also be applied to a direct type copying machine using photosensitive paper, and it goes without saying that the entire surface exposure technique can also be applied to the exposure method.

Furthermore, in the above embodiment, a through lens is used and the optical axis of the lens and the principal ray of the optical path coincide, but the principal ray may be an oblique ray of the lens, and an in-mirror lens may be used. In these cases, the amount of movement of the lens in the X and Y directions differs from the principal ray by the inclination θ component of the optical axis.

As described above, according to the present invention, by setting the original with the operating side of the copying machine as a reference, accurate positioning is ensured without causing individual differences among operators as seen in the central reference. Setting the copy paper setting and ejection position as the operator's reference not only simplifies the positioning mechanism based on the size of the paper feed tray or paper cassette, but also makes it easier and easier to handle paper jams. It can be done safely.

What is more noteworthy is that from the copy paper size W signal and the magnification f signal, the optical means is moved in the direction of the optical axis (1/m-1)f, and in the direction perpendicular to the optical axis _W0 /2-W/1+m Since the copy paper is moved, by simply specifying the desired copy paper and the desired magnification, it is possible to make an accurate copy on the copy paper set based on the operating side standards and eject it to the operating side. This eliminates the need to check the copy paper size, greatly simplifies the operation, and greatly reduces the labor involved. In addition, the original size signal and
Since the control device also selects the required magnification based on the desired copy paper size signal,
This eliminates the troublesomeness of the operator having to check the magnification or the size of the copy paper each time, and has an excellent effect of preventing operational errors such as out-of-size or blank spaces due to poor selection. .

[Brief explanation of drawings]

Figures 1 to 3 are explanatory diagrams of the optical system of the conventional device;
FIG. 4 is a schematic diagram showing an example of an apparatus to which the present invention is applied, FIG. 5 is a sectional view of an automatic document feeder, and FIGS. 9 to 12 are diagrams showing the flow of operation of the apparatus according to the present invention. 10...Photosensitive drum, 31...Document size detection device, 41, 41'...Paper feed tray.

Claims (1)

[Scope of Claims] 1. A document setting station and a paper feeding means that allow a document and copy paper to be set with respect to the copying machine operation side, and at least one lens that projects a light image of the document onto a photoreceptor. a variable magnification optical means, a moving means for moving the optical means in the optical axis direction and in a direction perpendicular to the optical axis, a copy paper size signal generating means, a magnification signal generating means, a maximum original size and a maximum copy paper size. When the width is _W0 , the size of copy paper is W, the magnification is m, and the focal length of the optical means is f, move the optical means in the optical axis direction (1/m-1)f, perpendicular to the optical axis. and control means for controlling the moving means to move the moving means in the direction and toward the operation side by W ₀ /2 −W/1+m.