JP2520645B2 - Copying device - Google Patents

Description

The present invention relates to a copying apparatus having a document size detection function.

[Conventional technology]

Generally, a copying apparatus such as an electrophotographic apparatus optically scans a document placed on a document table and forms a copied image based on the reflected light. In particular, in the conventional apparatus, in the case of a manuscript having no thickness, such as a region where no manuscript is placed, there is no gap when the manuscript is pressed by the pressure plate, the background of the pressure plate is copied, In the case of an original such as a book, since the pressure plate is not closed sufficiently and a gap is formed, the outer portion of the original is cut off in a black color when copying.

On the other hand, in recent years, a copying apparatus having a so-called original detection function has been developed and commercialized by scanning the entire area of the original plate once before copying, and detecting the size and the position of the original at this time. ing. This device
As shown in FIG. 4, this is a method of detecting the difference between the background of the original paper and the reflected light from the pressure plate that presses the original. Therefore, as the pressure plate, a colored pressure plate or a mirror surface pressure plate is used.

[Problems to be solved by the invention]

For this reason, in this apparatus, when the original detection is in operation, the outer portion of the original can be copied as a white background. However, when the original detection function is canceled and used, the outer portion of the original is not detected even in the case of a thin original. When entering the copy area, the platen portion is copied, so that a black edge is created in black-and-white copying.

By the way, as a case of canceling the document detection, a function for canceling the document detection is also necessary although there are various purposes depending on the user, such as the case where the scanning for the detection is omitted because the copying speed is desired to be increased or other users. That is a fact.

However, after further examination by the applicants,
In the copy mode as described below, it has been found that if the original detection is canceled, the copying apparatus itself becomes inconvenient. That is the case where the copying machine cannot recognize the size of the recording paper. For example, in the case of A3, A4, B4 sizes, etc., which are often used in daily work, a dedicated cassette is often used to feed paper, and in general, pins or irregularities indicating the size are provided on the cassette side to feed paper. The size is input to the copying machine. On the other hand, in the case of recording paper such as postcards, in most cases, it is not fed from the cassette, but is fed one by one from a separate manual feed port. . In the case of such manual paper feeding, it is not impossible to automatically detect the size of the recording paper fed by the copying machine, but it is extremely difficult in terms of configuration. Therefore, in the manual paper feeding, almost no device detects the paper feeding size.

In this way, if the document size is not detected and the document detection is canceled, the sizes of both the document and the recording paper are unknown, so the entire area must be copied to prevent image loss. For example, the maximum size is A3. In the case of a copying machine, when a postcard-sized original is copied while the postcard is manually fed and fed, the area B in FIG. 5 is not transferred as it is solidly developed on an image carrier such as a photoconductor. The part of the developer is directly collected by the cleaner.

FIG. 6 shows an example of a conventional electrophotographic apparatus. When the above is repeated, after the development by the developing device 17, the developer attached to the surface of the photoconductor 15 protrudes outside the recording paper 22. The solid black portion is scraped off by the cleaner 20 as it is, and part of it is scattered inside the machine to contaminate the inside, and eventually the capacity of the cleaner 20 cannot keep up, resulting in overflow and toner clogging. In addition, when a waste toner bottle having a small capacity is used, the bottle is filled up immediately, or the developing device itself consumes the developer abnormally, which is uncomfortable.

The present invention has been proposed in order to prevent the inconvenience in the use method as described above, and provides an extremely necessary and effective protection function for a copying apparatus having a document detecting means.

[Means and Actions for Solving Problems]

According to the present invention, in the paper feed mode in which the recording paper size cannot be detected, the above-mentioned inconvenience is prevented by forcibly executing the original size detection regardless of cancellation of the original size detection.

〔Example〕

 Hereinafter, the present invention will be described with reference to examples.

FIG. 1 is an external view of the apparatus of the embodiment. In FIG. 1, reference numeral 1 denotes a reader unit for reading a document, which has a structure as shown in FIG. In addition, 2 is according to the read signal,
A well-known laser beam printer mainly composed of an electrophotographic portion as shown in FIG. 6 is used as a printer portion for forming an image. Reference numeral 3 in FIG. 1 denotes a manual paper feed port, and the paper feed means is switched from the cassette 4 or 5 to the manual paper feed by tilting the manual paper feed port in the direction of the arrow.

Here, when the paper is fed from the cassette 4 or 5, the size of the paper and the orientation of the length and the width can be known by the pin provided on the cassette side at the joining surface between the cassette and the printer 2 which is not shown. It is configured like.

In addition, a CCD sensor 1 that is a document detection unit that optically scans the document table and detects the document size and position prior to copying.
3 and means for canceling document detection (not shown).

It should be noted that it is not necessary to detect the vertical and horizontal orientations of the paper, the vertical and horizontal orientations of the document, and the like.

Therefore, in the paper feed mode where the paper size can be detected by the shape of the cassette or deck, the image of the non-transfer portion corresponding to the outside of the detected recording paper size is detected when the original detection is cancelled. Should be converted to a white background signal on the reader or printer side, and when the original is large and the transfer part protrudes from the recording paper while detecting the original, the outside of the paper size may be converted to the white background signal. .

On the other hand, in the manual feed mode, the manual feed port 3 is tilted in the arrow direction in FIG. 1 so that the function of the releasing means can be forcibly disabled even if the original detection function is released. Then, the micro switch 23
It is turned off and its logic circuit is constructed as shown in FIG.

In this way, in the reader unit shown in FIG. 4, first, by pre-copy scanning for document detection,
The size of the original 7 is read once. Then, scanning for reading the original image is performed. At this time, the surface of the pressure plate 6 on the original side is a mirror surface, and the size of the pressure plate 6 is about A3, while the original and the manual feed are Both paper size,
Assuming the postcard size and the relationship shown in FIG. 5, the CCD sensor 13 in the reader section receives the black signal at the portion shown in FIG. . It should be noted that the pressure plate 6 is not limited to the mirror surface type, and a colored type is often used. In this case, the signal is black or a signal close to black. If this is output to the printer 21 as it is, the non-transfer portion without the recording paper will be contaminated with toner. However, since the size of the original 7 has been read once by pre-scanning, the portion (B) of FIG. 5 is recognized as the portion without the original,
The reader unit converts the black signal to a white background signal and outputs the signal, and as a result, it is possible to prevent the non-transfer portion of the printer 2 from being contaminated with toner.

In some cases, it may be desirable to reselect and use cassette paper feed in the reader unit 1 with the manual paper feed port 3 still tilted in the direction of the arrow.
Alternatively, when the selection key 5 is pressed, the logic may be such that the forced document detection is canceled even if the paper feed port 3 is tilted in the direction of the arrow. (See FIG. 3) Further, the safety level can be further increased by using the following processing together. That is, the manual feed port 3 is tilted in the direction of the arrow, and when the reader 1 enters the manual feed mode, a message for inputting the manual feed paper size is issued to the reader. By doing this, even if you accidentally use a document that is larger than the size of the bypass paper, you can cut the image part of the document that protrudes from the recording paper according to the input paper size information, which is safer. .

In addition, various other modes related to document detection, for example,
Of course, the detected original may be used in combination with a center moving mode for outputting the original at the center of the recording paper. In addition, in the present embodiment, the case of manual copying is mainly described, but in addition to this, a cassette for feeding special size paper is used, and since various sizes of paper can be loaded in one cassette, The same operation can be performed in the case of using a so-called universal cassette, in which it is impossible to give the information of the paper size to the reader section with a pin or the like.
Further, it goes without saying that the recording paper may be paper of an overhead projector, tracing paper, or the like.

Further, in the present embodiment, the digital image processing type copying machine including the reader section and the printer section has been described. However, the present invention can be applied in the same manner to a conventional analog copying machine having a document detecting function. Needless to say.

〔The invention's effect〕

As described above, in the case where the recording paper size cannot be automatically detected in advance, the present invention can prevent wasteful consumption of the consumable material for forming the visible image. Further, when it is applied to an electrophotographic apparatus, it is very effective for preventing contamination of the copying machine due to scattering of untransferred toner and clogging of the cleaner.

[Brief description of drawings]

FIG. 1 is an external view of an embodiment of the present invention, FIGS. 2 and 3 are explanatory views of the operation of the same embodiment, and FIG. 4 is a schematic view of a reader section of a device on which the present invention is based, and FIG. FIG. 6 is an operation explanatory diagram of the conventional example and the embodiment, and FIG. 6 is a schematic diagram of the conventional example. In the figure, 1 ... Reader 2 ... Printer section 3 ... Manual feed port 4,5 ... Cassette 6 ... Colored pressure plate or mirror pressure plate 13 ... Original detection means

Claims (4)

(57) [Claims] 1. A document size detecting means for detecting a document size prior to copying, a releasing means for canceling the detection of the document size by the document size detecting means, and a paper feeding means for supplying recording paper. In a copying machine provided with a recording paper size detecting means for detecting the recording paper size stored in the paper feeding means, when executing a paper feeding mode in which the recording paper size cannot be detected by the recording paper size detecting means. A copying apparatus comprising means for forcibly executing the document size detection. 2. The function of the releasing means for releasing the detection of the document size by the document size detecting means when the paper feed mode in which the recording paper size detecting means cannot detect the recording paper size is executed. The copying apparatus according to claim 1, further comprising means for disabling it. 3. The recording paper size detecting means is provided with a means for detecting the recording paper size when the paper feed mode in which the recording paper size cannot be detected is executed. The described copying machine. 4. The copying apparatus according to claim 1, wherein the paper feed mode in which the recording paper size cannot be detected is a manual paper feed, a universal cassette or the like paper feed mode.