JPS5860768A - Copying machine - Google Patents

Abstract

PURPOSE:To detect a paper size with a spectrum light, by providing a light source, which can emit lights of first and second wavelength regions, and a resolving means which resolves reflected light irradiated from said light source to an original press plate placed on an original stand. CONSTITUTION:On the face, which faces to an original stand 11, of an original press plate covering over the platen 11, infrared rays of the emission spectrum of a lamp 19 are absorbed, and visible rays are reflected. This face is realized by making the surface white and working it roughly. A moving optical system is arranged under the stand 11. This moving optical system consists of the first moving optical system 21 having the lamp 19, which has the emission spectrum of visible rays - infrared rays, and a mirror 20 and the second moving optical system 22 having a mirror 22-1. Consequently, the light of a spectrum different from that of the light for exposure of a photoreceptor is used to detect a paper size.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copying machine, and in particular, it detects the size and dimensions (hereinafter referred to as size 5) of a document and automatically selects copy paper, and also automatically selects copy paper according to the size of the document. The starting position is changed.

Conventionally, in a copying machine, an operator selects the copy paper according to the size of the document, but if the operator makes a mistake in switching the cassette, the copying machine becomes an electroscopy machine.

In addition, position sensors such as a registration sensor and a reversal sensor are installed to start image formation when the optical system or the document table reaches a predetermined position, and to start image formation when the optical system or the document table reaches a predetermined position. It's reversed. Therefore, since image formation is started regardless of the size of the original, if the original is misaligned, the reproduced image will be missing.

Therefore, the applicant previously proposed in Japanese Patent Application No. 1-6λ994 a size detection device that eliminates this drawback, but the size detection device uses light of the same spectrum as the light spectrum at the time of exposure of the photoreceptor to detect the document size. Since the paper size is detected, the signal processing circuit for detecting the paper size becomes complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a copying machine that detects the size of a document using light having a spectrum different from the spectrum of light when exposing a photoreceptor, in order to eliminate such conventional drawbacks.

Hereinafter, the present invention will be described in detail based on the drawings.

FIG. 1 shows an embodiment of the copying machine of the present invention, and 7 is a document table on which a document is placed in the copying machine. In other words, the size manuscript has straight lines xo-xo', YO-YO', YA-YA', XmuX
Place the document in the area surrounded by A', and place the original of size B directly on the 41
XO-XO', yo-yo', YB-YB', XB-X
Place the original in the area surrounded by B', and the original of size c is placed on the straight line x.
o-xo', YO-YO', xc-xc', yc-rc
' Add the sum so that it is placed in the area surrounded by '.

7g is a document holding plate that covers the above-mentioned document table//, and the surface facing the document table/l absorbs, for example, infrared light of the emission spectrum of the Zump/de described later.
Allow visible light to be reflected. This can be achieved by whitening and roughening the surface as described above. Also, the manuscript table // K l! A copying machine power switch/9, a copy start command switch 13, a copy number setting keyboard 16, and a copy number display 17 are provided on the operation panel IJ in contact with the copy machine.

A moving optical system is arranged below the document table //. This moving optical system includes a first moving optical system 21 having lamps 1 and 2 having an emission spectrum of visible light to infrared light, and a first moving optical system having mirrors 2J and 2. Can be configured. The home positions of the first and first moving optical systems 2/, - are shown by points M, respectively, and when the above-mentioned copy start switch /3 is pressed down, the optical systems 〃 and 〃 are moved in the direction of arrow P. to measure the size of the original. Further, when the optical system 2/, the sword moves in the direction of arrow R, reflected light from the document is projected onto the photosensitive drum.

Here, the first optical system -/ is moved linearly at a constant speed in the direction of arrow P from the position shown by the dotted line, and the first moving optical system - is also moved in the direction of arrow P from the position shown by the dotted line. The above-mentioned item/
Move the optical system at - speed. In this way, the first moving in the direction of arrow P (forward movement) K
．． Stop the optical system 1, - at the position where it has finished scanning the original on the original platen 1, and then move in the direction of arrow R (backward movement) K.
After moving the drum and loading the image onto the photosensitive drum, it is brought to the home position.

Being so busy, number one. By reciprocating the first optical system〃,-, the lamp/? IIjL#4 is irradiated by the mirror, but the reflected light 61 from the JIE draft is reflected by the mirror
The optical path is set so that the light enters the lens uK through the /, and reaches the photosensitive drum via the half mirror 5, the mirror J, and the mirror.

The half mirror 62 reflects a predetermined ratio of visible light and infrared light from the original holding plate /g and the reflected light A/ from the original, and makes the reflected light enter a phantom mirror A4'. The mirror 4fll transmits visible light and reflects infrared light. The visible light and infrared light from the OFF-6 light is directed to a size detection circuit 60, detailed in FIG. Referring to Figure 3,
Visible light is supplied to the visible light detection equipment, and its detection output S/ is supplied to the game (or game) 47 via the inverter 66. On the other hand, infrared light is supplied to infrared light detection equipment, and its detection output S
Or game) A? supply to. As will be described later, the rising edge of the OR output (B/+S) of this OR gate t indicates the leading edge of the document, and the falling edge thereof indicates the trailing edge of the document.

On the other hand, around the photosensitive drum 1, there are a DC corona discharger 1, an ACC corona discharger 9, a dust imager 9 that adheres toner to the image formed on the photosensitive drum A transfer charger 30 that transfers the upper toner onto the transfer paper, a separation roller J/ that separates the transfer paper from the photosensitive drum described above, and three cleaners that remove the residual toner on the photosensitive drum N are arranged to remove the drum roller. Copies are made by rotating in the direction of arrow F and using known copying processes.

Reference numeral 33 is a cassette that stores 3 sheets of transfer paper of size A. An arm 36 swingably supported on a shaft JS is rotated in the direction of arrow S, and a rotating roller 37 integrated with the arm J6 is moved to the cassette 33. By pressing the transfer paper 34I stored in the guide roller 3-1
．． 3 de-co, 3t-3,,79-,7,3t
-4I, Jsu -q and guide passage to the transfer position of the photosensitive drum. The transfer paper that has been transferred at the transfer position is fixed by fixing rollers lI/, lI, and is ejected into a paper ejection tray.

In addition, we is a cassette that stores transfer paper lIS of size C, and the arm q7, which is swingably supported by the shaft BK, is rotated in the direction of arrow T to rotate integrally with the arm duct. In addition to pressing the transfer paper Q stored on the back of the cassette, the guide roller Jl-/
, J? -/, Jlney J, J9-J
, Jlf-4′.

3 Dada and guide 9. The transfer position of the photosensitive drum is guided through the cassette.As will be described later, when the document size is detected, one of the cassettes is selected.
A desired transfer paper is fed, but the transfer paper is temporarily kept on standby by the timing roller Jg-J, 39-3.

It is assumed that the distance from the timing roller 3 -3, 39-j to the transfer charger 30 is equal to the distance from the exposure position of the photosensitive drum 26 to the transfer charger JO.

In a copying machine configured in this way, the upper K
Place the l-ism manuscript, press it with the manuscript holding plate/1, and switch l! When is pressed, the optical systems 2/, - start moving in the direction of arrow P at a constant speed. Now, as shown in Figure cA), the white part of the manuscript held down by the manuscript holding plate/S.
Assuming that there is a black background part kOB in the frame, visible light is reflected by the presser plate /l and the white background part jOA, and the black background part 5
Since the light is absorbed at 0B, the output signal S/ obtained from the visible light detector becomes as shown in Figure 3(B). Also,
Since the infrared light is reflected only by the white background part jOA and absorbed by the holding plate /l and the black background part kOB, the infrared light detector a
The output signal S obtained from is 5 as shown in Figure (C). Therefore, the output signal S/ of the inverter 6 becomes K as shown in Fig.
/+82) becomes as shown in Fig. fE). That is, the time t/ is the leading edge of the original SO, and the time t is θθ than the original.
The document SOO size is detected by counting the time from time 1/ to t, and at time t, the optical system, 2/, and Q2 are stopped. /, - position detection can be omitted.

Also, based on the detected size, the arm 37 of the cassette 3J is driven in the direction of arrow S to send out the size of the transfer paper 3 to the guide 4tOK.

Therefore, the optical system λ/, Q2 stops at a position slightly moved in the direction of arrow P from the edge of the size document, and then starts moving in the direction of arrow R. Here, when the optical system moves from the home position shown by the broken line to the position corresponding to the size of the document, that is, at time t in FIG. 4 (2), the size of the transfer paper is fed. Then register with timing roller Jg-3, 3day 3.

Next, the optical system 1 is moved in the direction of arrow 8, and the timing rollers M-, 7, ? Rotation of the transfer paper 3 is started, the transfer paper bowl is fed toward the photosensitive drum, and copies are made using a well-known copying process.

According to the present invention as described above, the size of a document can be detected by a simple signal processing circuit, and the cost of the size detection device can be reduced. Furthermore, various controls can be easily performed using the document size detection output.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a copying machine to which the present invention is applied, FIG. Figure (4
) is a line diagram showing the state of the presser plate and the original, Figure d (B) ~
(E) is a waveform diagram showing signals of various parts of the size detection circuit. l/...Original table, l-...Indication arrow, /
J...-Operation panel, /q--Power switch,
is...Copy start command switch, /6...Copy number setting keyboard, /ri...Copy number display, 1g...Document holding plate,
/9... lamp, 〃・-mirror, co/・
...first moving optical system, n・-second moving optical system, 〃-/
・-Mi2-1 U...Lens, review, co-mirror, lagoon...Photosensitive drum E. -7... DC corona discharger, -g... AC corona discharger, -19... Current device, 30... Transfer charger, J/... Separation roller, 3-piece cleaner , J.
J...cassette, J-tei...transfer paper, J-yo...
・・Axis, 3 points・・Arm, Jri・・・
Rotating roller, J Zaichi/, 2.4! ,jq''/',ko,da-guide roller,3g-J,JdayJ...timing roller,
Su...Guide, Teru・-Cassette, Hiro 3・
-・Transfer paper, wabi...shaft, da7・-arm,
Intrusion/one rotation roller, A9...guide,
V・-Manuscript, 9A・-White area, 30B
・-Heat region, 60...Size detection circuit, 61.-Reflected light, 6 pieces...Half mirror-1U.-Reflected light, A41
...mirror, company ---visible light detector, A4
...Inverter, Menri・-or gate, 6t・
・・Infrared detector, S/, 82 ・・Detection output. Patent applicant Canon Co., Ltd. Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1) A light source that can emit light in at least first and second wavelength ranges, and a light source that emits light from the light source toward a document placed on a document table and a document holding plate that presses the document. a decomposition means that decomposes the reflected light into light in the first and second wavelength ranges, respectively; and a decomposition means that receives the light in the first and $2 wavelength ranges decomposed by the decomposition means and outputs a detection output. 1. A copying machine, comprising: first and first light receiving means for obtaining a document, and detecting the size of the document based on detection outputs from the first and first light receiving means. 2. A copying machine according to claim 1, wherein the light in the first wavelength range is visible light, and the light in the first wavelength range is infrared light. 3) A copying machine according to claim 1, wherein a surface of the document holding plate facing the document is treated to absorb the infrared light. (li) In the copying machine according to any one of claims 1 to 3, a signal obtained by inverting the detection output from the first light-receiving means and a detection output signal from the second light-receiving means are logically summed. , the size of the document is detected based on the time when the logical sum is at a high level.