JP2000214547A - Original size detecting device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original size detecting device and an original size detecting method capable of preventing the presence/absence of an original from being erroneously detected and accurately detecting original size. SOLUTION: A detection sensor 14 detecting the presence/absence of the original 20 detects the pressing surface 19 of an original cover 18 at a closed position C where the cover 18 is closed and does not detect the surface 19 at a half-opened position B where the cover 18 is half opened. The original 20 or the surface 19 of the cover 18 is detected at the positions B and C. Whether or not the original 20 is larger than specified size is decided based on the result of detection performed twice.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a document size detecting device and a document size detecting method.

[0002]

2. Description of the Related Art Conventionally, a stencil printing machine or a copying machine detects whether or not a document is present at a predetermined detection position on a transparent glass plate by a document detection sensor provided below a transparent glass plate on which the document is placed. There is an apparatus using a document size detecting device for determining a document size.

In this type of document size detection device, a reflection sensor is generally used as a document detection sensor, and the amount of light received by the document detection sensor differs depending on whether or not a document is present at a predetermined detection position on a transparent glass plate. The presence or absence of a document is thus detected. However, for example, when there is a solid black (large continuous black portion) of a document at a predetermined detection position, the amount of light received by the document detection sensor decreases, so that it is erroneously detected that there is no document, and the size of the document is reduced. An erroneous determination sometimes occurred.

[0004]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a document size detecting apparatus and a document size detecting apparatus capable of preventing erroneous detection of the presence or absence of a document and accurately detecting the document size. It is to provide a detection method.

[0005]

SUMMARY OF THE INVENTION The present invention provides a document size detecting device having the following configuration in order to solve the above technical problems.

The document size detecting device includes a transparent plate on which a document is placed, a document cover rotatably opened and closed between a closed position for pressing the document on the transparent plate and an open position retracted from the transparent plate. And placed under the transparent plate,
Light detection means for receiving reflected light from a detection position on the transparent flat plate and detecting whether or not the amount of received light is greater than a reference light amount, and placed on the transparent flat plate based on the detection result by the light detection means And a document size determining means for determining the size of the document. In the document size detecting device, the amount of light received by the light detection means from the document pressing surface of the document cover when the document is not on the transparent flat plate is such that the document cover is at the first position on the open position side. Sometimes, the light amount is smaller than the reference light amount, and when the document cover is at the second position on the closed position side, the light amount is larger than the reference light amount, and it is determined whether or not the document cover is at the first position. One position detecting means is provided. The light detecting means detects whether or not each light receiving amount when the document cover is at the first and second positions is larger than the reference light amount. The document size determining means determines the size of the document based on each detection result by the light detecting means when the document cover is at the first and second positions.

In the above arrangement, the reference light amount of the light detecting means is set to be smaller than the amount of light received by the light detecting means from the normal reflectance portion (non-solid black portion) of the document. The wavelength of the light used for the light detecting means is not limited to visible light, but also includes, for example, near infrared rays. If the document holding surface of the document cover is, for example, a surface having the same reflectance as the document, the amount of light received by the light detection means from the document holding surface of the document cover when there is no document on the transparent flat plate will be When the cover is at the first position on the open position side (it may be the open position itself), the light amount is smaller than the reference light amount, and the document cover is at the second position on the closed position side (it may be the closed position itself).
, It is possible to make it larger than the reference light amount. However, the document pressing surface of the document cover may be a light emitting surface that emits light when the document cover is at the second position (for example, a fluorescent surface that emits light by being irradiated with ultraviolet rays).

In the above configuration, the light detecting means can start the first detection when the document cover is at the first position based on the detection result by the first position detecting means. The light detecting means performs the second detection when the document cover is at the second position when the document cover is closed (for example, an operation of pressing a plate making start switch in a stencil printing machine, and a copy switch in a copying machine). (Pressing operation). Alternatively, after detecting that the document cover is at the first position, the process may be started after an appropriate time elapses when the document cover is considered to be closed.

According to the above configuration, when the document cover is at the first position on the open position side, if the amount of light received by the light detecting means is larger than the reference light amount, the document exists at the detection position on the transparent flat plate, If the amount of light received by the detecting means is smaller than the reference light amount, it is considered that the document does not exist at the detection position on the transparent flat plate, so that it can be determined whether the document size is larger or smaller than the predetermined size. However, when there is a portion of the document where the reflectance of the document is low, for example, a solid black at the detection position on the transparent flat plate, the amount of light received by the light detecting means is the reference light amount even though the document size is larger than the predetermined size. Therefore, the document size cannot be correctly determined by only one detection.

Therefore, the second detection result when the document cover is at the second position on the closed position side is used together. That is,
When the document cover is at the second position on the closed position side, the received light amount of the light detecting means is larger than the reference light amount by the pressing surface of the document or the document cover, regardless of whether the document size is larger or smaller than the predetermined size. Become. But,
In the case where there is a portion where the reflectance of the document is low at the detection position on the transparent flat plate, the amount of light received by the light detecting means is smaller than the reference light amount. Utilizing this second detection, it can be determined from the first detection result when the document cover is at the first position on the open position side whether the document size can be determined as it is or whether the determination needs to be reviewed. .

Therefore, erroneous detection of the presence or absence of a document can be prevented, and the size of the document can be accurately detected.

Preferably, the first position of the document cover is a predetermined position between the open position and the closed position.

According to the above arrangement, after the document cover is opened to the open position, and the document is placed on the transparent flat plate, and when the document cover reaches the first position while the document cover is being closed to start plate making and copying, the document cover is moved to the first position. The first position detecting means can detect the light, and the light detecting means can perform the first document detecting operation.

According to the above configuration, since the light detecting means operates immediately before the detection of the document size is required, the operation is not wasted. Since the document cover is considered to be completely closed after a lapse of a predetermined time after passing through the first position, the timer is started after the detection of the first position of the document cover, and after the lapse of the predetermined time, the detection light detecting means 2 It is also possible to perform the second document detection operation. Further, for example, in the case of illuminating the vicinity of the detection position on the transparent flat plate, by illuminating the document with the document cover being closed to some extent, it is possible to prevent the light detection means from malfunctioning due to external light or room light.

Preferably, the document size determining means includes
The light detecting means detects that the amount of light received when the document cover is at the first position is larger than the reference light amount, and the amount of light received when the document cover is at the second position is smaller than the reference light amount. At this time, a warning signal is output.

According to the above construction, when the document cover is at the first position, the light detecting means detects the document, but when the document cover is at the second position, the light detecting means also controls the document pressing the document cover. If the surface is not detected,
For example, when the document is shifted when the document cover is closed, the document size determination unit outputs a warning signal. With this warning signal, a warning message can be displayed, or the operation of stencil making or copying can be stopped in a stencil printing machine or copying machine incorporating a document size detecting device.

By the way, the second detection when the document cover is at the second position is started when an appropriate time is considered after the document cover is detected to be at the first position and the document cover is considered to be closed. In this case, even if the timer measurement is started after passing through the first position, the document cover may be rotated from the open position side (or the open position itself) to the closed position side before passing through the first position. Is detected,
A timer may be started.

Preferably, the first position detection sensor is
An angle sensor for detecting the opening / closing angle of the document cover.

According to the above arrangement, the angle sensor can detect not only the first position of the document cover as the first position detecting means but also the rotation of the document cover in the direction of the closed position. . Further, the second position of the document cover can be detected. Therefore, the configuration can be simplified.

In the case of a stencil printing machine, a stencil making error is not a waste of one copy, and therefore, the ability to detect the size of a document must be higher than that of a copying machine. The document size detecting devices having the respective configurations described above can accurately detect the paper size, and are particularly suitable for a plate making plate of a stencil printing machine.

The present invention also provides a document size detecting method.

The document size detecting method is to determine the size of the document based on whether or not the reflected light of the document placed on the transparent plate and pressed by the document cover can be detected by the light detecting means through a predetermined position of the transparent plate. This is a type of determination method.
When there is no original on the transparent plate and the original cover is at the first position retracted from the transparent plate, the light detecting means does not detect the original cover, and the original cover approaches the transparent plate. The light detecting means is configured to detect the document cover when in the second position. The document size determination method includes first to third steps. In the first step, when the document cover is at the first position, the detection result by the light detecting means is checked.
In a second step, when the document cover is at the second position, a detection result by the light detecting means is checked. In the third step, when there is detection by the light detecting means in both the first step and the second step, or when there is no detection by the light detecting means in both the first step and the second step Determines that the document is larger than a predetermined size, and when the first step does not detect the light by the light detecting means and the second step detects the light by the light detecting means, the document is smaller than the predetermined size. If there is a detection by the light detecting means in the first step and no detection by the light detecting means in the second step, it is determined that there is an abnormality.

According to the above-described method, erroneous detection of the presence or absence of a document is prevented by using two detection results of the first position where the document cover is not detected and the second position where the document cover is detected, and the size of the document is accurately determined. Can be detected.

The above document size detection method is particularly suitable for a plate making plate of a stencil printing machine.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an original size detecting apparatus according to an embodiment of the present invention will be described with reference to the drawings.

The document size detecting device is incorporated in a document table 10 of a stencil printing machine. As shown in the front view of the main part of FIG. 1 and the plan view of the main part of FIG. 2, the platen 10 generally includes a transparent flat plate 12, a document cover 18, a scanner 32 and a guide 30, and a document size detection sensor 14. And

The transparent flat plate 12 is a flat glass plate on which a document 20 is placed. A document scale plate 13 (shown only in FIG. 2) is provided on one side in the longitudinal direction (indicated by an arrow 90) of the transparent flat plate 12, and displays a document placement position according to the document size.

As shown in FIG. 1, a document cover 18 is rotatably fixed to the other side of the transparent flat plate 12 in the longitudinal direction. The document cover 18 is opened at an open position A approximately 90 degrees from a closed position C at which the document 20 placed on the transparent flat plate 12 is pressed.
It is designed to open up. A document cover angle sensor 17 (see FIG. 13) for detecting the opening / closing angle of the document cover 18 is provided at the rotation fulcrum 16 of the document cover 18 to detect the start of movement, the opening / closing direction, and the open / close position of the document cover 18. While the cover 18 rotates from the closed position C to the open position A, it can be detected that the cover 18 has passed a predetermined position, that is, a half-open position B.

Below the transparent plate 12, a scanner 32 and a guide 30 are arranged as shown in FIGS. The scanner 32 is a line sensor, and moves in the longitudinal direction 90 along the guide 30 in parallel with the transparent flat plate 12 to read the lower surface of the original 20 in contact with the transparent flat plate 12.

Further, a document size detection sensor 14 is arranged below the transparent flat plate 12. The document size detection sensor 14 is a reflection sensor arranged to face the transparent flat plate 12. As shown in FIG. 2, the document size detection sensor 14 sets A4 (2) when one edge of the document 22, 24, 26, 28 is placed at a predetermined position along the document scale plate 13.
97 x 210 mm) and letter size LTR (279
× 216 mm) outside the originals 22, 26,
A3R (297 × 420mm) and legal size L
It is arranged at a position inside the originals 24 and 28 of GR (216 × 356 mm).

The original size detecting sensor 14 receives the reflected light from the original 20 or the original pressing surface 19 of the original cover 18 when the original cover 18 is at the closed position C, and when the original cover 18 is at the half open position B, If the document 20 is at the detection position, the reflected light from the document 20 is received, and if the document 20 is not at the detection position, the reflected light from the document pressing surface 19 of the document cover 18 is received.

The original pressing surface 19 of the original cover 18 has a reflectance similar to that of a normal white original. The document size detection sensor 14 outputs a white level when the received light amount is larger than the predetermined threshold value, and outputs a black level when the received light amount is smaller than the predetermined threshold value. The predetermined threshold value is smaller than the amount of light received from a document having normal reflectance or the document pressing surface 19 of the document cover 18 at the closed position C, and
A value larger than the amount of light received from the document pressing surface 19 of the document cover 18 at the half-open position B without the document 20 on the document 2 is set.

Thus, when the document cover 18 is at the closed position C, the document size detection sensor 14 outputs a white level by light reflected from the document 20 having a normal reflectance or from the document pressing surface 19 of the document cover 18. . Document cover 18
Is in the half-open position B, if the originals 24, 28 of A3 or legal size are placed,
The document size detection sensor 14 outputs a white level by the reflected light from the light source 8. A4 or letter size manuscript 2
2 and 26, the reflected light from the originals 22 and 26 is not received and the reflected light from the original pressing surface 19 of the original cover 18 is smaller than the threshold value. 14 outputs a black level.

Therefore, when the document cover 18 is in the half-open position B
According to the combination of the outputs from the document size detection sensor 14 when the document is at the closed position C and when the document is at the closed position C, for example, it is possible to determine whether the documents 24 and 22 are A3 or A4 size as shown in Table 1.

[0035]

[Table 1]

That is, when there is a normal reflectance portion of the A3 size document 24 at the detection position of the document size detection sensor 18, the document cover 18 is in the half-open position B and the closed position C, The original size detection sensor 18 outputs a white level by the reflected light from the light source 24. In the case of an A3-size original 24 having a black portion having a reflectance smaller than a predetermined value at the detection position of the original size detection sensor 14,
When the document cover 18 is at the half-open position B or at the close position C, the black level is output by the reflected light from the document 24. On the other hand, in the case of the A4 size document 22, since there is no document 22 at the detection position of the document size detection sensor 14,
When the document cover 18 is at the half-open position B, a black level is output, and when the document cover 18 is at the close position C, a white level is output by light reflected from the document pressing surface 19 of the document cover 18. When the document cover 18 is at the half-open position B, it outputs a white level, and when it is at the closed position C, it outputs a black level.
When the document cover 8 is in the half-open position B, the document 24 of A3 size is placed.
It is considered that this is an abnormal state that does not normally occur, such as when the object has moved, so it is processed as an error. For example, a warning sound is issued, and a message is displayed on the display panel to place the original on the platen.

The same can be determined for the letter size and the legal size.

The control system for determining the document size is configured as shown in the block diagram of FIG. That is, the CPU 50 that controls the control includes the document cover angle sensor 17, the document size detection sensor 14, and the plate making start switch 52.
Are connected, and while a signal is input, a determination result of the document size, that is, a determination signal is output.

Next, the operation will be described.

The document cover 18 of the document table 10 is opened, and a document 20 for plate making is placed at a predetermined position on the transparent flat plate 12 along the document scale plate 13.

Then, the document cover 18 is closed. When the document cover 18 passes through the half-open position B while the document cover 18 is being closed, the document cover angle sensor 17 detects this and the document size detection sensor 14 performs the first detection.

Next, when the stencil making start switch 52 (see FIG. 3) of the stencil printing machine is pressed, usually the original cover 18 is pressed.
Is considered to be at the closed position C, the document size detection sensor 14 performs the second detection. Then, the CPU 50 determines the document size based on the detection result of the document size detection sensor 14 at the half-open position B and the closed position C, and outputs a determination signal on the determination result.

If the original size can be determined correctly,
Based on the determination signal, the scanner 32 scans the original 20 on the transparent plate 12 while moving along the guide 30 as in the conventional apparatus. At this time, the moving distance of the scanner 32 in the longitudinal direction 90 is controlled based on the determination signal, so that the scanner 32 does not move more than necessary for the A4 or letter-size originals 22 and 26, and the scanning is completed earlier. It may be.

On the other hand, if the document size cannot be determined correctly, the above-described error processing is executed based on the determination signal.

As described above, the document size detecting device used for the document table 10 can prevent erroneous detection of the presence or absence of a document and can accurately detect the document size.

It should be noted that the present invention is not limited to the above embodiment, but can be embodied in various other forms.

For example, if the document size detection sensor 14 is appropriately moved or a plurality of document size detection sensors 14 are provided at appropriate positions, the paper size can be classified into more types and determined.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of a document table using a document size detection device according to an embodiment of the present invention.

FIG. 2 is a plan view of a main part of the document table of FIG. 1;

FIG. 3 is a main block diagram of a control system.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 Document table 12 Transparent flat plate 13 Document scale plate 14 Document size detection sensor (light detection means) 16 Rotating fulcrum 17 Document cover angle sensor (first position detection means) 18 Document cover 19 Document holding surface 20 Document 21 Lower surface 22 A4 size Paper 24 A3 size paper 26 Letter size paper 28 Legal size paper 30 Guide 32 Scanner 50 CPU (document size determination means) 52 Plate making start switch 90 Arrow A Open position B Half open position C Close position

Claims (7)

[Claims] 1. A transparent flat plate (12) on which an original (20) is placed, a closed position (C) for pressing the original (20) on the transparent flat plate (12), and retracted from the transparent flat plate (12). A document cover (18) rotatably opened and closed between an open position (A) and a transparent plate (12);
Receiving reflected light from the detection position on the transparent flat plate (12),
A light detecting means (14) for detecting whether the amount of received light is greater than a reference light amount, and a document (20) placed on the transparent flat plate (12) based on the detection result by the light detecting means (14) Document size determining means (5)
0), the light detecting means (14) is provided with the original pressing surface (18) of the original cover (18) without the original (20) on the transparent flat plate (12). When the document cover (18) is at the first position on the side of the open position (A) when the amount of light received from the document cover (19) is smaller than the reference light amount,
8) is configured to be larger than the reference light amount when it is at the second position on the side of the closed position (C), and a first position for detecting whether or not the document cover (18) is at the first position. A detection unit (17), wherein the light detection unit (14) detects whether or not each light reception amount when the document cover (18) is at the first and second positions is larger than the reference light amount. The document size determining means (50) determines the size of the document (2) based on each detection result by the light detecting means (14) when the document cover (18) is at the first and second positions.
A document size detecting device for determining the size of 0). 2. The apparatus according to claim 1, wherein the first position of the document cover is a predetermined position between the open position and the closed position. 2. The document size detection device according to 1. 3. The document size determination means (50), wherein the light detection means (14) detects that the amount of light received when the document cover (18) is at the first position is larger than the reference light amount, and 3. The document size detecting device according to claim 1, wherein a warning signal is output when the light receiving amount when the cover is at the second position is smaller than the reference light amount. 4. The document size detecting device according to claim 1, wherein said first position detecting means is an angle sensor for detecting an opening / closing angle of said document cover. . 5. A stencil printing machine, characterized in that a stencil plate (10) is provided with the original size detecting device according to claim 1. 6. A light detecting means (14) detects reflected light of an original (20) placed on a transparent flat plate (12) and pressed by an original cover (18) through a predetermined position of the transparent flat plate (12). An original size determination method for determining the size of the original (20) depending on whether or not the original (20) can be obtained.
When the document cover (18) is at the first position retracted from the transparent flat plate (12), the light detecting means (14)
Does not detect the original cover (18), and when the original cover (18) is at the second position close to the transparent flat plate (12), the light detecting means (14) detects the original cover (18). A first step of examining a detection result by the light detecting means (14) when the document cover (18) is at the first position; and setting the document cover (18) to the second position. A second step of examining a detection result by the light detection means (14); and a detection by the light detection means (14) in both the first step and the second step, or the first step If there is no detection by the light detecting means (14) in both the second step and the second step, the original (2
0) is determined to be larger than the predetermined size, and if the first step does not detect the light detecting means (14) and the second step detects the light detecting means (14), the document (20) is determined to be smaller than the predetermined size, and if the first step has detected by the light detecting means (14) and the second step has no detection by the light detecting means (14), And a third step of determining an abnormality. 7. A stencil printing machine, wherein the size of a stencil document (20) is detected by the document size detection method according to claim 6.