JPS6265028A - Image forming device - Google Patents

Abstract

PURPOSE:To detect an original size from the opened state of an original pressing plate by installing a light emitting means and a photodetecting means on the bottom of a translucent platen and giving constitution combining an original size detection control means and a copying action control means to said means. CONSTITUTION:When the action control means 22 issues a command detecting an original size, an original size detection in the original size detection control means 21 starts. First the original pressing plate 2 is decided to be opened or not. If it is opened, the photodetecting elements of sensors 11-14 start reading, and data on the photodetecting element extracted by the prescribed time is stored. When the plate 2 is detected to be closed after an original P is set to a translucent plate 1p, data before said point is read out of memory. Thus the data immediately before the pressing plate 2 is closed can be read, and decides an original size. Then data stored in memory so far is erased, and outputted to the copying action control means 22.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an image forming apparatus having a detection means for determining the size of an original by using reflected light from an original to be copied.

[Prior art]

In a conventional image forming device, for example, a copying machine, the device for determining and detecting the size of the original to be copied by its reflected light is as follows: (1) A light-emitting and light-receiving element is arranged at a predetermined location within the original pressing plate that presses the original. and a means for reading out the size when the crimp plate is closed. Devices that use ``stages,'' etc., have been proposed to determine size by detecting differences in reflected light.

However, each of these conventional fittings has the following problems. In other words, 1) In the device described in item (1) of 1j, the element is disposed within the document pressure plate, which not only complicates the structure of the pressure bonding plate that opens and closes, but also reduces the shadow of the sensor when handling thin documents. appears in the copied image, and the size cannot be detected unless the pressure bonding plate is closed.

In addition, in the apparatus described in item (2) above, in order to utilize the difference between the light reflected by the pressure bonding plate and the light reflected by the document, the surface of the pressure bonding plate on the document side is colored so that the difference appears greatly. Not only does it require treatment, but it is also easily affected by dirt.

〔the purpose〕

The present invention has been made in view of the above problems, and includes a light emitting means and a light receiving means disposed below a transparent mounting table, and a combination of these with a document size detection control-1 stage and a copying operation control means. With this configuration, the drawbacks of the conventional image forming system are eliminated and the image forming device is equipped with a document size detection device that can detect the document size when the document pressure plate is open. +
The aim is to provide 2t.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

First, the configuration will be described with reference to FIGS. 1 to 4.

Reference numeral 1 denotes a translucent IJI loading stand that holds a rectangular transparent plate tp on the surface of which the original to be copied P is set as a frame; 2, the transparent IJI loading stand is pivotally supported on one long side of the placing stand L so as to be openable and closable; P through IJ
The original pressure bonding plate 3, which is in pressure contact with the I plate 1p, serves as an opening/closing detection means for detecting opening/closing of the pressure bonding plate 2.
A switch 11 is provided at one corner of the surface of the storage table l, and reflective sensors 11-14 are provided at predetermined locations below the storage stand l (see Fig. 2, 6, and 3) to emit light as a light emitting means. It is a combination of an element and a light-receiving element (both not shown) as a light-receiving means.

Furthermore, the planar layout of each reflective sensor 11-14 will be explained in detail with reference to FIG. The size of the original P to be copied is A3. B4.
Taking A4 (horizontal) and A4R (vertical) as an example, if each size is based on the front left corner 1st in the figure, then A3
Since the document P will be set at the positions indicated by the solid line for B4, the dashed line for A4, and the dashed-dotted line for A4R, each sensor 11-14 is placed at a location corresponding to each size. will be established. Therefore, the sensor outputs for each case where the original P is set at each of the above positions are as shown in the first table.

In other words, each of the sensors 11 to 14 is arranged so as to be able to discriminate four different sizes of the original P. It goes without saying that in order to increase the size of the document P, the number of sensors can be increased to accommodate the increase in size, thereby making it easier to discriminate the document P.

Also, as will be described later, as shown in FIG.
It is configured to read the reflected light when it is open.

Furthermore, in the block diagram shown in FIG. 4, 21 is a document size detection control means, 22 is an operation control means for controlling the copying operation, and 25 is a command line between the two control means 21 and 22. be.

Next, details of size detection will be explained with reference to the f:iSJ diagram and FIG. 5.

FIG. 5 is a flowchart showing an example of the control operation for document size detection in the above configuration, and the control operation will be described using this flowchart.

When the operation control means 22 receives a command to detect the document size, the control means 21 starts detecting the document size. First, in step 51, it is determined whether or not the original pressing plate (hereinafter referred to as "pressing plate") 2 is opened, and when it is opened, reading by the light receiving element of the sensor 11-14 is started (52).

Then, this data is stored in the memory (53), and if copying has not been started within a certain predetermined time period (54), for example, the data is sequentially stored in the memory until the pressure plate 2 is closed (56). In other words, the data of the light receiving element extracted every predetermined time (10 ns) is stored.Next, after the original P is set on the transparent plate IP, the pressure plate 2 is closed. is detected (56), the previous point (e.g. 1
(57), this makes it possible to read the data immediately before the pressure plate 2 is closed, and from this data it is possible to determine the document size (58). 59) and outputs it to the copying operation control means 22 (60).
), In addition, if the copying operation is started with the pressure plate 2 open, such as with a thick original or a real original, the copy start signal from the copying operation control means 22 should be judged 55),
The data in that state is read out from the memory 61), the size is determined 58), the memory is cleared 5.9), and the size is output (60).

It is preferable that the above-mentioned fixed time period for reading data before a certain period of time when the pressure plate 2 is closed is determined based on the time the operator spends on closing the pressure plate 2, depending on the configuration of the pressure plate 2 and the like.

In addition, in the single control example, the read data is stored as is (
53) in Figure 5, but each time.

The same thing happens even if you convert it to size and store it.

Furthermore, in this embodiment, the configuration is described in which the light emitting element and the light receiving element are combined as a set, but the detection part can be uniformly irradiated with a single light emitting element, and the copy document can be copied during the copying operation. Naturally, it can also be used as a light source that uniformly irradiates the light.

Note that in the present invention, since the document size is detected with the pressure plate 2 in an open state, there is a possibility that it may be affected by external light. It is also possible to do so.

In addition, if the light emitted from the light emitting element affects the copied image, turn off the light emitting element except when detecting the document size.
It can also be set to FF.

Furthermore, the presence or absence of the document P can also be detected by a sensor that detects documents of all sizes, such as the sensor 14 described in this embodiment.

〔effect〕

As described above, the present invention includes a reflective sensor that detects a document set on a transparent storage table from below, a document pressure plate opening/closing detection device, a document size detection control device, and a copying operation control device. Since we have provided an image forming device with a document size detection device of It is possible to eliminate the need for processing and to easily detect the size of thick originals such as books. Another advantage is that it is not affected by external light or dirt.

[Brief explanation of the drawing]

FIG. 1 is a side view showing members related to document setting in an embodiment of the present invention. Figure 82 is an explanatory side view showing the situation in which sensors are similarly arranged, Figure 3 is an enlarged plan view showing the relationship between the set position of each size of original and the sensor, and Figure 4 is an illustration of the original size detection device. The block diagram and the ptSS diagram are also flowcharts showing control operations for document size detection. P...Original to be copied 1...Transparent@Place 3...Stitch 11...Sensor 12...Sensor 13...・Sensor 14・・・Sensor diagram 1

Claims (5)

[Claims] (1) A transparent mounting table for setting a document to be copied, an openable/closable document pressure bonding plate for holding the document, a light emitting means and a light receiving means arranged below the placement table, and a means for detecting opening/closing of the pressure bonding plate. An image forming apparatus having a document size detection device, characterized in that the size of the document is determined based on the output data of the light receiving device before the time when the closing of the pressure bonding plate is detected by the opening/closing detection device. (2) The image forming apparatus according to claim 1, wherein the size of the original is determined based on the output data of the light receiving means before a predetermined time from the time when the closing of the original pressing plate is detected. (3) The image forming device according to claim 1 or 2, further comprising a control means for turning off the light emitting means at least during a copying operation. (4) An image forming apparatus according to claim 1 or 2, characterized in that the image forming apparatus has a light source that uniformly irradiates the original to be copied during a copying operation, and also serves as a light emitting means. (5) The light-receiving means includes a plurality of light-receiving elements, and at least one of the plurality of light-receiving elements is arranged at a position to detect originals of all sizes. The image forming apparatus according to any one of Item 4.