JPH0435737B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a document size detection method, and more specifically, to automatically and accurately detect 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.

<Conventional technology> There has been a strong demand for multi-functionality in office equipment such as copying machines, and products with automatic magnification and automatic paper selection functions are becoming available. .

In order to achieve the above-mentioned automatic scaling function and automatic paper selection function, it is necessary to have a function to automatically detect the size of the document, and for this purpose, a document size detection device is provided. Specifically, it has a coloring member at a predetermined position of the document holder, a light emitter that illuminates the coloring member, and a light receiver that receives reflected light from the coloring member, and furthermore, it has a coloring member at a predetermined position to perform a copying operation. It has a drive means for retracting the photoreceptor before performing the printing, and automatically detects the size of the document based on signals from the photoreceptor corresponding to the portions blocked by the document and the portions not blocked by the document. Composition (Unexamined Japanese Patent Publication No. 1983-
(Refer to Publication No. 22424), and a plurality of optical sensors are attached to predetermined positions of a long body that can be bent and expanded in accordance with the movement of a movable frame that supports an optical part, and a plurality of optical sensors are attached to predetermined positions of a long body that can be bent and expanded to follow the movement of a movable frame that supports an optical part, and the document is detected before the movable body starts operating. A structure that automatically detects the size of the document depending on which optical sensor detects the document before closing the presser foot (patent application)
60-148780) is provided.

<Problems to be Solved by the Invention> In the above configuration, not only is a special drive mechanism required to retract the photoreceptor, but also the exposure of the original is There is a problem that time is required to retract the photoreceptor before starting the process, and the time from when a predetermined key operation is performed to when the exposure of the document is completed becomes long.

Furthermore, the above configuration has the advantage that it does not require any special evacuation operation and can shorten the time from when a predetermined key operation is performed until the exposure of the original is completed. .

However, since the point at which the document size should be detected is set in advance as one point for each size of document, depending on the state of the document image at this point (for example, a bold portion may appear at this point). If the document exists, etc.), it will be determined that the document does not exist even though the document does exist, and there is no guarantee that the document size is reliably detected accurately.

<Objective of the Invention> The present invention has been made in view of the above-mentioned problems, and provides a document size detection method that can accurately detect the document size almost unaffected by the condition of the document image. It is intended to.

<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 document size at each predetermined position where documents of various sizes that can be used can be distinguished from other types of documents. After carrying out the document size detection operation with a plurality of document detection sensors attached as their respective home positions positioned at the home positions, the size detection is performed using these sensors from the home position. The document is moved at least once within the range of the document to be processed, the document size is detected at the moved location, and if the document is detected at at least one of the home position and the moved location, the document size is detected. This method is characterized by detecting the document size based on data.

However, the sensor for detecting the document may be moved following the movement of the optical section, or may be moved independently of the movement of the optical section.

<Operation> With the document size detection method configured as described above, the document size is detected by determining which sensor is detecting the document while the document detection sensor is in the home position. Then, in a state in which the sensor is moved, the document size is detected by determining at least once which sensor is detecting the document, and when the document size is detected by any of the detection operations, The detected size can be obtained as the document size. The detection operation by the sensor described above is performed at the home position and at the moving location, but since the moving location is within the range of the original whose size is to be detected from the home position, the moving distance is short. It is possible to quickly and reliably detect the document size.

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. Even if the configuration requires a special drive source to perform the document size detection operation, the document size detection operation described above can be performed.

<Examples> Hereinafter, examples will be described in detail with reference to the accompanying drawings showing examples.

FIG. 1 is a perspective view showing an embodiment of an apparatus for carrying out the document size detection method, and includes a first moving frame 1, a second moving frame 2, and a long body 3. As shown in FIG.

The first moving frame 1 includes a light source 11 and a reflecting mirror 1.
The second movable frame 2 supports the reflecting mirrors 21 and 22. and,
One end of both the moving frames 1 and 2 is connected to the guide shaft 13.
and engage the other end with the guide rail 1.
By supporting it on the upper surface of 4, it is possible to reciprocate.

To explain in more detail, the optical section composed of the light source 11 and the reflecting mirrors 12, 21, 22 has a wire 15 fixed at both ends at predetermined positions in the main body of the device, and a wire 15 connected to guide pulleys 16, 17 and a tension pulley. 18 and the driving drum 19, and is also wound around a driven pulley 23 attached to a predetermined position on the second moving frame 2, and further fixed at a predetermined position on the first moving frame 1, thereby making it reciprocate. Therefore, the above moving speed is the first moving frame 1.
is twice that of the second moving frame 2.

The long body 3 has a pair of rods 31 and 32 as a shaft 3.
They are rotatably connected to each other by 3, and
The tip of one rod 31 is rotatably connected to a predetermined position of the device main body by a shaft 34, and the other end is rotatably connected to a predetermined position of the first moving frame 1 by a shaft (not shown). are doing. And the rod 31,
An optical sensor 3 consisting of a light emitting body 38 and a light receiving body 39 is attached to a predetermined position of 32 by a mounting member 36.
7 are installed facing diagonally upward. Note that both rods 31 and 32 have a hollow central portion, and lead wires connected to each optical sensor 37 are guided through this hollow portion.

FIG. 2 is a diagram explaining the mounting position of the optical sensor 37 with respect to the rods 31 and 32, and corresponds to the position where various standard size originals are set. It is installed accordingly.

Furthermore, since each of the optical sensors 37 is mounted close to the bottom surface of the contact glass on which the original is set, there is no need to make the directivity of the light emitting body 38 very high, so that the cost can be reduced.

With the above configuration, the first
In a state where the moving frame 1 is located at the home position, the optical sensor 37 is operated while the document holder (not shown) is being closed, and it is determined which optical sensor 37's photoreceptor 39 has received the reflected light from the document. This allows the first document size detection to be performed. After the first document size detection is performed, the optical sensor 37 is moved a predetermined distance as shown by the two-dot chain line in FIG. In this state, the second document size detection can be performed in the same manner as described above.

The first and second document size detection operations described above are performed while the document holder (not shown) is being closed, and there is no need to open and close the document holder twice.

Therefore, even if a bold portion or the like is located at the position corresponding to the optical sensor 37 on the original, it can be determined with certainty that the original exists, and the exact original size can be determined based on the result of this determination. Detection can be performed.

For example, the determination as to which of the above two detection results to adopt may be based on whether or not the detection level by the optical sensor 37 has changed after the first determination.
If there is no change, maintain the detection level and
If the black level changes to the white level, the detection level after the change is retained; if the white level changes to the black level, the detection level before the change is retained,
It is conceivable to detect the document size based on this retained data, but it is not limited to such a determination; for example, the document size may be detected only based on a detection level equal to or higher than a predetermined reference level. It is also possible.

Thereafter, by moving both the moving frames 1 and 2 forward, the original can be exposed. In this case, the elongated body 3 follows the forward movement of the first moving frame 1 and is bent around the shaft 33, so that
The forward movement of the first moving frame 1 is not obstructed.

Further, when moving backward, the elongated body 3 extends in the opposite direction to the above, so that the backward movement of the first moving frame 1 is not obstructed in this case as well.

In the above embodiment, the moving frames 1 and 2 must be moved in order to detect the document size, but in a copying machine, the optical section is set to the home position when the power is turned on. To confirm the position, move frames 1 and 2
Since it is necessary to move the optical sensor 37 back and forth, this mechanism can be applied when moving the optical sensor 37, and there is no problem that the control becomes particularly complicated.

The moving distance of the optical sensor 37 is within the size range determined by the standard document size (for example, about 5 mm)
If so, it is possible to accurately detect the size of a normal original, and the moving distance at the end of the moving frame 1 for this purpose is, for example, approximately 10 mm to 50 mm.
It can be set within the range of mm. However, if the size of the documents to be identified is small and the difference between them is large, the moving distance can be set to a large value.

It should be noted that the present invention is not limited to the above-mentioned embodiments. For example, a plurality of optical sensors 37 may be mounted in a direction perpendicular to the exposure direction, and a plurality of optical sensors 37 may be mounted at a predetermined distance independently of the moving frames 1 and 2 by a drive source (not shown). In addition to adopting a configuration in which the document size is moved, it is also possible to detect the document size at three or more locations.In this case, when the white level is determined by any of the detection operations, the The detection level is held, and the document size is detected based on the held data. In addition, various design changes can be made without changing the gist of the invention.

<Effects of the Invention> As described above, the present invention determines the presence or absence of a document at at least two points separated by a predetermined distance, and when a document is detected at any of the points, it detects the presence or absence of a document based on the detection data. Since the document size is detected using the sensor, it is possible to accurately detect the document size without being affected by the condition of the document image.Furthermore, since the distance to move the sensor is short, the above-mentioned accurate size detection is possible. , which has the unique effect of being able to be carried out quickly.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of an apparatus for carrying out a document size detection method, and FIG. 2 is a diagram illustrating the mounting position of an optical sensor. DESCRIPTION OF SYMBOLS 1... First moving frame, 11... Light source forming an optical section, 12, 21, 22... Reflecting mirror forming an optical section, 37... Optical sensor.

Claims (1)

[Scope of Claims] 1. In an apparatus that exposes a document to light by moving an optical part, each predetermined position at which a usable document of various sizes can be distinguished from other types of documents is defined as a respective home position. After performing the document size detection operation with the multiple attached document detection sensors located at the home position, move these sensors from the home position within the range of the document whose size should be detected. The document is moved at least once, and the document size is detected at the moved location. If the document is detected at at least one of the home position and the moved location, the document size is detected based on the detection data. A document size detection method characterized by performing detection. 2. The document size detection method according to claim 1, wherein the sensor for detecting the document is moved to follow the movement of the optical section. 3. The document size detection method according to claim 1, wherein the sensor for detecting the document is moved independently of the movement of the optical section.