JPS638640A - Detecting method for size of original - Google Patents

Abstract

PURPOSE:To attain the accurate detection of original size without being influenced due to the state of an original image by executing the detecting operation of the original size by a sensor on the way of closing an original press and then executing the detecting operation again in the closed state of the original press. CONSTITUTION:An output signal from an optical sensor 37 is kept at the low level until the original press 41 is almost completely closed and then turned to the high level. An output signal from a NOR gate 44 is kept at the high level until the half closed state of the original press 41 is detected by a photointerrupter 43, and after detecting the half closed state, the output signal from the NOR gate 44 is turned to the low level. After depressing a print key 45, an AND gate 46 is opened and a high level signal is outputted from the gate 46. Thereby, an output signal from an XOR gate 47 is held at the high level until timing T1, held at the low level from the timing T1 to timing T2 and then turned to the high level again after the timing T2, so that no existence of an original on a position corresponding to the optical sensor 37 can be identified.

Description

[Detailed Description of the Invention] Industrial Application Fields The present invention relates to a document size detection method, and more specifically, to self-help and accurate detection of the size of a document set on a contact glass. The present invention relates to a method for detecting the size of an original document.

<Prior Art> Conventionally, there has been a strong demand for multi-functionality in OAIffi devices such as copying machines, and as one of these, devices having a self-help variable magnification function are increasingly being provided.

In order to achieve the automatic magnification change function described above, it is necessary to have a function to automatically detect the size of the document, and for this purpose, document size detection devices are provided. Specifically, ■ It has one light emitter that is turned ON and OFF when the document holder is opened and closed, and two light receivers, and the light from the light emitter is reflected by the document and received by both light receivers. (Refer to Japanese Unexamined Patent Application Publication No. 1978-78849) that automatically detects the size of the document based on the combination of light reception conditions in the copying machine; The size of the document can be detected automatically by driving the detection means when the document holder is placed in a half-open state (Japanese Unexamined Patent Publication No. 58-173733).
(Refer to Book II) is provided.

<Problems to be Solved by the Invention> In the above #1 configuration, the document size is detected using only one light emitter and two photoreceptors, so if the number of types of III increases. The problem is that it cannot be addressed.

Furthermore, even if there are only a few types of documents, if there is a high-density area such as solid black around the edges of the document, the document may be detected as having a size that excludes the high-density area. There is a problem with becoming.

In addition, in the above configuration (■), since the detection means are arranged according to the type of document, the size of the document can be detected even if the number of types of document to be detected increases. However, since the document detection operation is performed only when the document holder is half-open, if there is a high-density area at the edge of the document, it is detected that the document is of a size that excludes the high-density area. The problem is that it ends up being

If the document size is erroneously detected as described above, an incorrect magnification ratio will be selected due to the natural magnification ratio, resulting in a problem that it will not be possible to obtain the desired copy image. It turns out.

<Object of the invention> This invention was made in view of the above problems,
It is an object of the present invention to provide a document size detection method that can accurately detect the document size without being affected by the state of the document image.

Means for Solving the Problems> In order to achieve the above object, the document size detection method of the present invention provides a method for detecting the size of a document at a predetermined position where it is possible to distinguish usable documents of various sizes from other types of documents. After installing the document detection sensor and performing the document size detection operation with the document detection sensor while closing the document holder,
The document size detection operation is performed again with the document holder closed.

However, the sensor for detecting the document may be one that can be moved following the movement of the optical section.

With the document force and noise detection device configured as described above, if you set the document in the specified position and close the document holder before exposing the document by moving the optical part, the document holder will be automatically closed while the document holder is closed. In this step, the document detecting sensor detects whether the document is nice, and then the document size is detected again with the document holder closed, and the final document size can be detected based on the results of both detections.

To explain in more detail, if there is a high-density area at the edge of the document, and it is determined that there is no document in the high-density area while closing the document holder, if the document is left unattended, the document is really not present. It is not possible to determine whether it does not exist or whether a high concentration part exists but cannot be detected. However, since the document size is detected even when the document holder is closed, if there is really no document present, the white reflective part of the document holder is detected and a high-density area of the document is detected. In this case, the white reflective portion of the document holder is not detected, so by taking this detection bundling into consideration, the document size of the page can be detected.

When performing the above action, it is preferable if the sensor can be moved following the movement of the optical part, since no special drive source is required to move the sensor. J3 can prevent the occurrence of shadows caused by the sensor.

<Example> Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

FIG. 7 is a perspective view showing an embodiment of a device for carrying out the document size detection method, and shows a first moving frame (1), a second moving frame (2), and a long body (3). have.

The first moving frame (1) includes a light source (11) and a reflecting mirror (
12), and the second moving frame (2) supports the reflecting mirrors (21) and (22). Then, connect one end of both moving frames fll+21 to the guide shaft (
13) and the other end to the guide rail (
14) By supporting it on the upper surface, it is possible to reciprocate.

To explain in more detail, the optical section composed of the light source (11) and reflecting mirrors (12), (21), and (22) is
Wire (15) with both ends fixed in place on the device body
Guide pulley (16017), tension pulley (1)
8), and while winding it around the drive drum (19),
The driven pulley (2) installed at a predetermined position on the second moving frame (2)
3), and is further fixed at a predetermined position on the first moving frame (1), so that it can be moved back and forth. Therefore, the above movement speed is such that the first movement frame (1) is the second movement frame (2).
) will be twice as much.

The elongated body (3) has a pair of rods f31 and (32) rotatably connected to each other by a shaft (33),
The tip of one of the rods (31) is rotatably connected to a predetermined position of the device body by a shaft (34), and the end of the rod (31) is connected to the first transfer frame (1) by a shaft (not shown). It is rotatably connected to a predetermined position. Then, the light emitting body (38) is attached to the specified position of the rod (31) (32) by the member (36).
), and an optical sensor (37) consisting of a photoreceptor (39)
Multiple pieces are installed facing diagonally upward. The rods (31, 32) have a hollow center, and lead ridges connected to each optical sensor (37) are guided through the hollow.

Figure 6 shows the optical sensor (
37) is a diagram illustrating the position, and is attached in correspondence with the position where documents of various standard sizes are set, and corresponding to a part of the area of each document that protrudes from the document one size smaller. Specifically, the mounting positions of the optical sensors (37) are as follows: optical sensor (37a) that is compatible only with A3 size originals, optical sensor (37b) that is compatible with only A3 size originals, and FOLIO size originals. ,A
Optical sensor (37c) that only supports 3 sizes, FOLIO size, and B4 size originals, Optical sensor (37d) that only supports A3 size, FOLIO size, B4 size, and A4 size originals, A3 size, FOL10 Optical sensor (3
7e).

Furthermore, each of the optical sensors (37) is mounted close to the bottom surface of the contact glass on which the original is set, so there is no need to make the directivity of the light emitting body (38) very high.
You can get 1J cheaply.

4 and 5 are diagrams that do not directly show the configuration for detecting the state of the document holder (41).
) Attach the action piece (42) to the predetermined position of the action piece (42).
) is attached to the main body of the copying machine to identify the half-open state based on the operating state of the copying machine.

FIG. 1 is an electrical circuit diagram (not showing the electrical configuration) of a device for implementing the document size detection method of the present invention, and shows the output signal from the optical sensor (37) and the photointerrupter (43). The output signal is supplied to the NOR gate (44), and the output signal from the optical sensor (37) and the output signal from the print key (45) are supplied to the AND gate (46), and further, The output signal from the NOR gate (44) and the output signal from the AND gate (46) are supplied to an XOR gate (47).

Next, the document size detection operation will be described in detail with reference to FIGS. 2 and 3.

FIG. 2 is a signal waveform diagram corresponding to a case where the peripheral edge of the document does not have a high moisture area, and timing T1 indicates the point when the document presser is half-open, and timing T2 indicates the point when the document presser is closed. There is.

In this case, place the document slightly outside the periphery of the document. ? As shown in FIG. 2A, the output signal from the optical sensor (37) is at a low level until the document holder (41) is almost fully opened, and then becomes a high level.

In addition, as shown in Figure 2B, a photo interrupter (4
The output signal from the NOR gate (44) is high until the half-open state of the document holder (41) is detected by 3), and the output signal from the NOR gate (44) is high after the half-open state is detected.
The output signal from the terminal becomes low level (see Figure 2C).

Before the print key (45) is operated, the AN
The D gate (46) is closed and outputs a low level signal, but after the print key (45) is operated, the AN
The D gate (46) is opened and outputs a high level signal (see second diagram, E).

Therefore, the output signal from the XOR gate (47) is
It is at a high level until timing T1, and at timing T
1 to timing T2 (see FIG. 2C), and becomes high level again after timing T2, indicating that there is no document at the position corresponding to the optical sensor (37). can be identified.

FIG. 3 is a signal waveform diagram corresponding to a case where the peripheral edge of the document has a high-density portion, in which timing T1 indicates when the document presser is half-open, and timing T2 indicates when the document presser is fully open.

In this case, as shown in FIG. 3A, the output signal from the optical sensor (37) located slightly outside the periphery of the document is transmitted until the document holder (41) is almost fully opened, and thereafter. It is at a low level throughout.

In addition, as shown in Figure 3B, a photo interrupter (4
The output signal from the NOR gate (44) is at a high level until the half-closed state of the document holder (41) is detected by 3), and after the half-open state is detected, the output signal from the NOR gate (44=
) becomes low level (see Figure 3C)
.

Before the print key (45) is operated, the AN
The D gate (46) is closed and outputs a low level signal, and the print key (45) is operated to output the AND gate (4).
6) outputs a low level signal even after it is opened (see Figure 3, E).

Therefore, the output signal from the XOR gate (47) is
Timing] It is at a high level until 1, it is at a low level from timing T1 to timing T2, and it is at a low level after timing T2 (see Figure 2 C).
It can be determined that a document is present at the position corresponding to the optical sensor (37).

Note that the output signals of the optical sensors other than the optical sensors located inside the boundary portion do not change when the document holder is half-open or fully open, so the XOR gate (47 ) remains at low level after timing T1.

Therefore, the document size can be accurately detected based on the output signal level from the XOR gate corresponding to each optical sensor (37).

(Margins below) Table 1 Also, since the optical sensor (37) is attached to rods (31) and (32) that mutually rotate into a bent state following the movement of the optical part, the exposure operation of the original There is absolutely no negative impact on the.

It should be noted that the present invention is not limited to the above-mentioned embodiments. For example, it is possible to detect the completely closed state of the document holder (41) with a sensor and automatically perform the document size detection operation. In addition, various design changes can be made without changing the gist of this light.

<Effects of the Invention> As described above, the present invention detects the document size based on the output signal of the optical sensor when the document holder is in the half-open state and the output signal of the optical sensor when the document holder is in the fully open state. Therefore, it is possible to accurately detect the document size without being affected by whether or not there is a high-density portion at the periphery, which is a unique effect.

[Brief explanation of the drawing]

Fig. 1 is an electric circuit diagram showing the electrical configuration of the device for carrying out the document size detection method; Figs. 2, J3, and 3 are signal waveform diagrams explaining the document size detection operation; and Fig. 4 is the document size detection method. FIG. 5 is a schematic side view showing the configuration for detecting the state of the document presser; FIG. 6 is a diagram illustrating the mounting position of the optical sensor; FIG. 7 is a perspective view showing an embodiment of an apparatus for implementing the document size detection method. (1)...First moving frame, (11)...Light source constituting the optical section, (12) (21)...
)(22)...Reflecting mirror constituting the optical section, (37)
・・Optical sensor, (41) ・・Document holder, (43)・
··Photo-interrupter,

Claims (1)

[Claims] 1. The original can be read by moving the optical part. Various types of equipment that can be used for exposure Distinguish size originals from other types of originals Can be placed in place for document detection Attach the sensor and close the document holder. Inside, a sensor for document detection detects the original. After performing the document size detection operation, the document Check the document size again with the presser foot closed. Manuscripts characterized by performing intellectual actions Size detection method. 2. The sensor for document detection moves the optical part. It is something that can be moved by following The manuscript size described in claim 1 Detection method.