JP3007753B2 - Document size detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document size detecting device used in an image forming apparatus such as a copying machine or a printer.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a printer using an electrophotographic system, an electrostatic latent image is formed on a photoreceptor by exposing and scanning an original placed on an original mounting table. Is performed. by the way,
The electrostatic latent image formed on the photoreceptor is subjected to visible image processing by a developing device and then transferred to a recording medium such as recording paper. Are fed out after being selected by the sheet feeding device. For this reason, in the related art, there is an apparatus provided with a function of automatically selecting the size of a recording medium according to the size of a document image to be copied, and also automatically selecting the size in the image forming apparatus itself. That is, this apparatus is provided with a structure for detecting the size of the document placed on the document placing table when selecting a recording medium, and has a structure shown in FIG. 10 as an example. This structure includes one side A1 in the longitudinal direction of the document and one edge A2 in the width direction corresponding to a direction perpendicular to the longitudinal direction.
Is set as a document placement reference edge, and an edge A1 located on one side in the longitudinal direction of the document placement table A is provided.
Is a document scale on which marks for aligning edges in the width direction of the document are marked. Then, at a position lower than the original placing table where there is no problem in moving the exposure scanning optical system and forming the exposure optical path, the size in the longitudinal direction and the size in the width direction of the original can be optically detected. The detection sensors B1 and B2 are arranged.
These detection sensors B1 and B2, as shown in FIG.
The light is emitted from the light emitting unit B3 toward the document on the document table A,
The detection light reflected on the document surface is received by a light receiving unit B via a lens B4.
5 is introduced. Therefore, the light emitting unit B
The arrangement relationship between 3 and the light receiving portion B5 is such that the optical path surface is parallel to the document placement reference edges A1 and A2 so that the size of the document in the longitudinal direction and the width direction can be detected. The detection sensors B1 and B2 divide the detection light beam emitted from the light emitting section B3 in a plurality of directions by a diffractive member, and detect the detection light beam when it is reflected on the document surface located in each optical path. The beam is incident on any of the light receiving portions B5, whereby the document size in the longitudinal direction and the width direction is detected. In FIG. 10, the reflection position of the detection light with respect to the size in the longitudinal direction and the width direction of the document that can be detected by the respective detection sensors B1 and B2 is indicated by a numeral in a circle. Further, the emission and incidence angles of the light emitting unit B3 and the light receiving unit B5 described above are set to about 6 to 13 degrees so that the non-detection sensitivity distance with respect to the document on the document table is determined. The non-detection sensitivity distance is a limit distance at which the sensitivity of the light receiving unit B5 in the detection sensors B1 and B2 can be obtained. If the distance is longer than this, optical detection of the document cannot be performed.
The detection of the detection sensors B1 and B2 is started by the closing angle of the document holding plate C provided to be able to be opened on the document table A. Therefore, the document holding plate C A switch D that operates according to the closing angle of the document pressing plate C is provided on the base end side of the document. For example, as shown in FIG. 12, the switch D is turned on when the position indicated by the reference symbol α, that is, when the document pressing plate C is almost completely closed, and the detection sensor B1,
B2 is operated, and is turned off when the position indicated by reference numeral β, that is, in the same state as when the document pressing plate C is almost fully opened, and the operation of the detection sensors B1 and B2 is stopped.

In such a structure, the document table A
Document placement reference edge A located on one side in the width direction of the document above
When one end of the original in the width direction is pressed against the original 2 and one end of the original in the longitudinal direction is applied to the original scale, the original is placed and set, and the original pressing plate C is closed. The sensors B1 and B2 start operating, and the sizes of the document in the longitudinal direction and the width direction are detected according to the positions of the detection sensors B1 and B2 incident on the light receiving unit B5, and the document size is determined. I have.

[0004]

In the above-described structure for detecting the size of the original, the detection sensor B
1. Depending on the position of the switch D that controls the operation of B2, accurate document size detection may not be possible. That is, at the closing angle of the document pressing plate C shown in FIG.
1. When the document pressing plate C is in the middle of setting the operation start and operation stop timings of B2 (the position indicated by reference numeral γ in the drawing), the operation stop position of the detection sensor C indicated by reference β has not been reached. This means that the detection sensors B1 and B2 are maintained in operation. Therefore, in this state, the reflected light is received not only from the original surface but also from the back surface of the original pressing plate C due to the variation in the sensitivity setting of the detection sensors B1 and B2. First, the reflected light from the document pressing plate C may be received in a state where it is confused with the detection light beam for detecting the document size. For this reason, a detection result that does not match the size of the actual document will be obtained. Also, in FIG.
As shown by the two-dot chain line, even when the orientation of the original on the original placing table is placed in a so-called oblique state, or when the original is not correctly pressed against the original placing reference edge. If the arrangement direction of the light emitting portion B3 and the light receiving portion B5 in the detection sensors B1 and B2 is parallel to the document placement reference edge, the document edge located at a position deviating from the position of the detection sensors B1 and B2 is detected. Therefore, the maximum size among the detected sizes is determined as the document size. As a result, a copied image may be obtained in which the copied document image is oblique on the recording medium or the image position is shifted and protrudes. In addition, the conventional image forming apparatus does not warn the operator of such a case, that is, a case where the original is set incorrectly. Therefore, once the original is set, the original pressing plate C is again set. Unless is opened, it is not possible to determine a document placement error, and to know the state only after obtaining a copy image, as a result, useless copying is performed.

In view of the above-mentioned problems in the conventional document size detection structure, it is an object of the present invention to accurately detect when a document is placed and set in an erroneous state, and in particular, to detect an erroneous state. An object of the present invention is to provide a document size detecting device having a structure capable of eliminating useless copying by making it possible to warn when a document has been placed and set.

[0006]

In order to achieve this object, a first aspect of the present invention is a document size detecting apparatus which determines a document size by detecting a size in a longitudinal direction and a size in a width direction of the document. A document placing table having a document placing reference edge at least one end of which is aligned in the width direction of the document, and provided so as to be openable with respect to the upper surface of the document placing table. A document pressing plate for pressing the document, means for detecting a closing angle of the document pressing plate, and a light emitting unit which is disposed at a position below the document mounting table where the size of the document in the longitudinal direction and the width direction can be detected; And a lens for splitting the detection light emitted from the light emitting unit toward the original and reflected on the original surface into a plurality of optical paths, and a light receiving unit on which the detection light is imaged by the lens. Detecting means for setting the optical path surface of the detection light beam between the light section and the light receiving section so as not to be parallel to the document mounting reference edge of the document mounting table; closing angle detecting means for the document pressing plate; and the detecting means Are respectively connected to the input side, and the output side is connected to the size display means and the display means of the document placement state, and the detection means is operated by a signal from the closing angle detection means, and the detection means Control means for judging the document size based on the signal and displaying the result and the document placement state, respectively.

According to a second aspect of the present invention, one of a plurality of beams of the detecting means arranged at a lower portion of the document table is near an end surface of the document table corresponding to one end in the width direction of the document and one end in the longitudinal direction of the document. And the arrangement direction of the light emitting unit and the light receiving unit is set so that the optical path surface of the detection light beam from the light emitting unit to the light receiving unit is oblique with respect to the end surface of the document table. I have.

Further, the invention according to claim 3 is characterized in that the emission / incident angle between the light emitting part and the light receiving part of the detecting means is set at 18 to 35 degrees.

According to a fourth aspect of the present invention, the control means uses an output signal from the detecting means obtained by detecting the end face of the document table and an output signal obtained by detecting the inside of the end face. The document size is determined and the result of the determination is output to a display unit.

Further, according to a fifth aspect of the present invention, when the closing angle detecting means is deactivated after the control means outputs a signal for displaying the result of judging the document size based on the output signal from the detecting means. The display of the determination result is reset, and when the closing angle detecting means is operated again, the document size is determined based on a signal from the detecting means.

[0011]

According to the present invention, the detection light beam emitted from the light emitting section and reflected on the original surface is divided into a plurality of parts, and the optical path surface of the detection light beam is set obliquely. One is emitted to the end face on the original placement reference edge side, and the other is emitted to the inside of this end face. Therefore, if no detection is made on the end face side, it is determined that the proper placement state is not achieved.

Further, according to the present invention, the document size is detected based on the completely closed state of the document pressing plate and a signal from the control unit .

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a layout diagram schematically showing a main part of an original size detecting apparatus according to an embodiment of the present invention. In FIG. 1, an original size detecting apparatus 1 includes an original placing table 2 and a detecting means 3 as main parts. Have. That is, in FIG. 2, the document placing table 2 is configured such that one end in the width direction of the document and one end in the longitudinal direction that is a direction perpendicular to the document placing edge are placed on the document placing reference edge 2.
A, 2B, and among these reference edges, the document placement reference edge 2B located at one end in the longitudinal direction is a document scale with a mark for positioning the edge in the width direction of the document. I have.

Below the document table 2, a detection means 3 for detecting the size of the document in the longitudinal direction and the width direction is provided. Although the details of the detection means 3 are not shown, the detection means 3 has the same structure as that shown in FIG. 11, and divides the detection light beam emitted from the light emitting section into a plurality of optical paths by a diffractive member, and is located in this optical path. The detection light beam reflected from the document surface is guided to a light receiving unit via a lens. In the case of the present embodiment, a plurality of the detection means 3 are arranged in the longitudinal direction of the document to apply the position of the detection light beam divided by diffraction to all of the positions along the longitudinal direction of the document. In the width direction, one is arranged because the number of divided detection light beams can be sufficiently applied.

Further, the optical path surface obtained between the emission surface and the incidence surface of the detection light beam between the light-emitting portion and the light-receiving portion in the above-described detection sensor 3 is inclined so as not to be parallel to the document placement reference edge. Is set. Therefore, when the reflection position is indicated by the number in a circle in FIG. 2 according to the arrangement direction of the light emitting unit and the light receiving unit, as shown by the position of the minimum number in each sensor 3, the detection light beam One is emitted toward an end face corresponding to one end in the longitudinal direction and the width direction of the document placing table 2, and the other detection light beam is emitted inward from this end face. Moreover, in the direction along the longitudinal direction of the document, the size of the document in the longitudinal direction is detected in the direction along the longitudinal direction of the document, and the state of the document when the document is shifted or tilted from the document placement reference edge is determined according to the arrangement direction of the light emitting unit and the light receiving unit. In addition, in the width direction of the document, it is possible to detect the size of the document in the width direction and the state in which the document is shifted or inclined from the document placement reference edge. In other words, when detecting the state of a document placed and set in a state shifted or inclined from the document placement reference edge, reflected light from the end face on the document placement reference edge side is not received, and the other end face is not detected. Is detected by any of the light receiving units, and the detection result indicates that the width of the detection light beam is smaller than the width of the original in the longitudinal direction detected by the detection sensor 3 positioned along the longitudinal direction on the original table. When the detection result by the detection sensor 3 in the direction does not match the size in the longitudinal direction, it is determined that the original is placed erroneously.

The emission / incident angle for setting the non-detection sensitivity distance to the document surface by the light-emitting unit and the light-receiving unit is set to 15 to 35 degrees, thereby setting the non-detection sensitivity distance (see FIG. 12). ) Is shorter than that of the related art, so that the document size can be detected only when a document pressing plate described later swings to a position where it can be considered that the document pressing plate is almost completely closed.

On the other hand, as shown in FIG. 1, a document holding plate 4 whose base end is supported by the image forming apparatus main body so as to be openable is provided on the upper surface of the document placing table 2. The document pressing plate 4 allows the document to be set on the document table 2 when opened, and when closed, presses the set document to the surface of the table. During the closing process, the operation of the detection sensor 3 is controlled. For this reason, the document holding plate 4
A switch 5 serving as a detecting means for detecting a closing angle of the document pressing plate 4 is disposed at a base end of the document pressing plate 4. The switch 5 is connected to a control means 6 described later, and the document pressing plate 4 When closed, a signal for operating the detection sensor 3 is output. The switch 5 outputs a signal to operate when the document pressing plate 4 swings to a position corresponding to the non-detection sensitivity distance of the detection sensor 3 as a timing for outputting a signal for operating the detection sensor 3. When the document holding plate 4 swings to a position corresponding to this distance or more, the detection sensor 3
Is not output for operating the device.

Accordingly, since the non-detection sensitivity distance of the detection sensor 3 is shortened, the document pressing plate 4 is displaced to a position corresponding to the non-detection sensitivity distance, and the detection sensor 3 is almost completely closed. Only then does the operation start. The detection sensor 3 for which such operation timing is set operates only when the document pressing plate 4 is completely closed, and stops the emission and incidence of the detection light beam by the detection sensor 3 when not completely closed. Therefore, the chance that the reflected light from the document holding plate 4 is confused with the document size detection light is reduced as compared with the conventional structure in which the light receiving state is maintained even when the document is not completely closed. I have.

On the other hand, the control means 6 controls the overall operation of the image forming apparatus. In FIG. 3, a main part is constituted by, for example, a microcomputer. The switch 5 for detecting the closing angle and the detection sensor 3 are connected via an I / O interface (not shown),
On the output side, a display unit 7 for displaying a paper size selected according to the original size and the magnification, a display unit 8A for displaying the original state, a transfer paper selection switch (not shown), and a copy start key (Start key) 8B An operation unit 8 further provided with a magnification setting key (not shown), a drive motor 9 of the image forming apparatus, and a paper feed unit 10 are connected to each other. In the control means 6, when the operator does not make an input relating to the selection of the size of the transfer paper by the operation unit 8 and is in a so-called automatic selection mode, when the detection sensor operation start signal is input from the switch 5, the detection sensor 3 is turned on. Is activated, the original size is determined according to the output signal from the detection sensor 3, and the result of the determination is output to the original size display section 7A. The control means 6 also determines the state of the document placed. In this case, if the detection position in the longitudinal direction of the document does not match the detection position in the width direction, It is determined that the placement of the document is incorrect. Therefore, for example, in a case where one edge in the width direction of the document is deviated from the document placement reference edge of the document table, taking into account that reflected light from the document placement reference edge side end face is not received. It can be determined that the size detection result in the longitudinal direction does not match the size detection result in the width direction with respect to this size, and the same determination is performed even when the document is placed diagonally. . Further, in the control means 6, when the document pressing plate 4 is opened and the detection sensor operation signal is not output from the switch 5 while the document size is being displayed, the document size data which has been detected so far is detected. And the display is reset, and when the original is placed again and the original pressing plate 4 is closed, when the operation signal of the detection sensor 3 is output from the switch 5, this detection result and the previous detection result Is displayed after being compared. When displaying the document size and the state of placement of the document, a signal for selecting a transfer sheet corresponding to the document size is output to the sheet feeding unit 10. When the transfer paper is selected, if the original is not placed properly and is shifted or tilted, it is displayed that the original is not placed properly and the original size obtained from the detection result is displayed. A signal for selecting a transfer sheet corresponding to the maximum size is output to the sheet feeder to prepare for the start of copying. Further, the control means 6 determines the size of the transfer paper based on the document size determined from the detection result in accordance with the magnification ratio input in the operation unit 8 and outputs the signal to the paper supply unit 10. At the same time, if there is no transfer paper of the determined size, this is displayed. When the signal from the switch 5 is not input, that is, for example, when a thick original such as a book is placed on the control unit 6, the control unit 6 cannot cover the original pressing plate 4. When the start key 8B is turned on in the operation unit 7, a drive signal to the main motor 9 of the image forming apparatus is taken in.
The detection and determination of the document size are performed.

Since the present embodiment has the above configuration,
The procedure will be described with reference to the flowchart showing the operation of the control means 6, as shown in FIG. That is, FIG. 4 shows a main routine for document size detection. In this routine, when the image forming apparatus is started, initialization for executing a copying process is performed. Then, the document placement state (indicated as set deviation in FIG. 4) and the document size are detected. The detection of the document placement state is shown in FIG. 5 and subsequent figures, and in each figure, the number given in the circle indicates the reflection position of the detection light beam shown in FIG. 2, and the reflected light from this position. When a beam is received, a signal from the detection sensor 3 is output. In the subroutine shown in FIG. 5, when an ON signal is input from the switch 5 which operates according to the closed state of the document pressing plate 4, a command for data reading is issued, and then the output signal from the detection sensor 3 is output. Is determined. In the subroutine shown in FIGS. 6 to 8, the output signal from the detection sensor 3 is determined by any one of the light receiving units of the detection sensor 3 located in the longitudinal direction and the width direction of the original on the original placing table 2. This is performed by determining whether or not the output is a signal. In the drawing, as to the input of the output signal from the light receiving section of the detection sensor 3, a state is shown in which the document size is determined according to the light receiving state from the reflection position shown in FIG. In the determination of the document placement state, when the reflected light beam from the end face side of the document placement reference edge including the document scale is received by the light receiving portion, the document is placed in the longitudinal and width directions. Since the edges correspond to the proper placement state in which the edges are pressed against the document placement reference edge and the document scale, the output is used to determine the document size, and data relating to the document size based on the determination result is registered. . . On the other hand, when a signal is output from a light receiving unit other than the end face side, it is determined that the edge of the document is not pressed against the document placement reference edge or the document scale, and A signal for instructing confirmation is output to display unit 8A.

When the detection of the original size and the detection of the original placement state (indicated as a set deviation in FIG. 4) are completed, the detected original size and change when the original placement state is proper. The selection of the transfer paper according to the magnification is executed. That is, the selection of the transfer paper is executed by the size detection processing in the routine shown in FIG. 4 based on the data relating to the document size based on the size in the longitudinal direction and the size in the width direction of the document described above. The choice is
In the subroutine shown in FIG. 9, it is determined whether or not the determined document size matches the size of the transfer paper accommodated in the paper feeding unit in the longitudinal direction and the width direction. When the size of the accommodated transfer paper in the longitudinal direction and the width direction matches the size of the original in each direction, the transfer paper of that size is selected and the transfer paper size is displayed. And a signal for feeding out the transfer paper is output to the paper feeding unit 10. On the other hand, if the size of the document in the longitudinal direction and the width direction from the detection result does not match the size in each direction on the side of the transfer paper housed in the paper feeding unit, that is, If the size in the longitudinal direction and the width direction does not match the size in the longitudinal direction and the width direction on the original side, the orientation of the original placed on the mounting table surface, for example, the orientation in the longitudinal direction is stored. A signal for indicating that the orientation of the transfer paper is not correct is output to the display unit 8A.

When the detection of the original size and the selection of the transfer paper size are performed, it is determined in the main routine shown in FIG. 4 whether or not a copy start key (start key) is input. Then, when it is inserted, control relating to the copying process is executed, and copying to transfer paper is executed. In the control of the copying process, data relating to the document size and the transfer paper size are held when copying is performed a plurality of times from the same document. The copying process is performed by performing size detection for each document placed and set on the table and selecting a transfer sheet. The detection of the document size based on the output signal from the detection sensor 3 is performed not only when the document pressing plate 4 is closed but also when a thick document is placed. In this case, as described above, the detection sensor 3 starts operating in accordance with the input of the copy start key (start key), takes in the document size data, and determines the document size. Has become. Further, in the document size detection, when the switch 5 is turned off, the document size data up to that point is reset, and when the switch 5 is turned on when the document holding plate 4 is closed again, the detected data is reset. The comparison is performed, and the result of the comparison is displayed on the display unit 8A.

Then, it is determined whether or not the copying process has been completed.
For example, the determination is made by comparing the value of the copy number count with the copy number command value, and when the determination is completed, post-processing for the control related to the copy process is executed. In this post-processing, for example, in addition to performing a binding operation of a transfer sheet after copying, a storage registration of data necessary for performing an initialization process in a copying process or a stop control of a mechanical component is performed. It is. In this post-processing, the control means 6
In the above, it is also possible to perform learning on the data used for detecting the document size and the document placement state.In this case, for example, updating of the document placement state determination criteria according to the frequency or It is possible to perform processing such as resetting the allowable range for the size determination criterion.

[0024]

As described above, according to the present invention, the emission surface of the detection light beam from the light-emitting portion by the detection means used for detecting the size in the longitudinal direction and the size in the width direction of the document, and The arrangement direction is set so that the optical path surface of the reflected light beam obtained on the incident surface to the light receiving unit is oblique so as not to be parallel to the original placing reference edge, and is emitted from the light emitting unit and reflected on the original surface. The detection light beam is divided into a plurality of parts, and one of them is emitted toward the end face located on the original placement reference edge side, and the other detection light beam is emitted inside the end face. Only when the reflected light at the end face is received, it can be determined that the placement of the document is appropriate. Therefore, when the detection light beam from the end face side is not received, it can be easily determined that the edge of the document is not pressed against the document placement reference edge and is not in a proper placement set. it can.

Further, according to the present invention, when the operation of the detecting means is controlled by the closing angle of the document pressing plate, the emission / incident angle of the detection light beam between the light emitting portion and the light receiving portion of the detecting means is determined by the document The value is set so that the non-detection sensitivity distance at which the document size can be detected only at the position corresponding to the case where the presser plate is completely closed is set, so that the detection means does not operate during the opening process. Can be Therefore, when the detecting means operates in the process of being opened, it is possible to prevent a situation in which reflected light from the document pressing plate is confused with a detection light beam for document size detection,
An accurate document size can be detected. Therefore, the operator can know the placement state of the document before the start of copying from the content displayed on the operation unit, so that it is possible to eliminate the need to increase unnecessary copying.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a schematic configuration of a document size detecting device according to an embodiment of the present invention.

FIG. 2 is a plan view for explaining an arrangement configuration of a detection unit in the document size detection device shown in FIG.

FIG. 3 is a block diagram for explaining a configuration of a control unit used in the document size detecting device shown in FIG.

FIG. 4 is a flowchart for explaining a main routine for explaining the operation of the control means shown in FIG. 3;

FIG. 5 is a flowchart showing a subroutine executed in the main routine shown in FIG. 4;

FIG. 6 is a flowchart illustrating a subroutine executed in the main routine shown in FIG. 4;

FIG. 7 is a flowchart for explaining a subroutine executed in the main routine shown in FIG. 4;

8 is a flowchart illustrating a subroutine executed in the main routine shown in FIG.

FIG. 9 is a flowchart illustrating a subroutine executed in the main routine shown in FIG.

FIG. 10 is a plan view for explaining an arrangement configuration of a detection unit in a conventional document size detection device.

FIG. 11 is a side view schematically showing a configuration of a main part of the detection means shown in FIG. 10;

FIG. 12 is a side view for explaining a problem in the document size detecting device shown in FIG. 10;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 document size detection device 2 document placement table 2A, 2B document placement reference edge 3 detection sensor serving as detection means 4 document holding plate 5 switch serving as closing angle detection means 6 control means 7 document size display section 8 operation section 8A document placement Position display section B1, B2 Detection sensor B3 Light emitting section B4 Lens B5 Light receiving section

Claims (5)

(57) [Claims] 1. A document size detecting device for determining a document size by detecting a size in a longitudinal direction and a size in a width direction of the document, wherein a document placement reference at least one end of the document in the width direction is aligned. An original mounting plate having an edge, an original pressing plate which is provided so as to be openable on the upper surface of the original mounting plate and presses the original when closed, and detects a closing angle of the original pressing plate A light-emitting unit and a light-emitting unit and a detection light emitted from the light-emitting unit toward the document and reflected by the surface of the document. A lens that divides the light into a plurality of light paths, and a light receiving unit on which the detection light is focused by the lens, and an optical path surface of a detection light beam between the light emitting unit and the light receiving unit is a document on the document table Detecting means set in a state not to be parallel to the mounting reference edge, closing angle detecting means of the document pressing plate and the detecting means are respectively connected to the input side, and size display means and the document mounting state on the output side. Control means for operating the detecting means in response to a signal from the closing angle detecting means, determining a document size based on a signal from the detecting means, and displaying the result and the document placement state, respectively. Means for detecting the size of a document. 2. A document size detecting apparatus according to claim 1, wherein one of a plurality of beams of the detecting means arranged at a lower portion of the document table corresponds to one end in the width direction of the document and one end in the longitudinal direction of the document. A document size in which the arrangement direction of the light emitting unit and the light receiving unit is set so that the light is emitted near the end surface of the mounting table and the optical path surface of the detection light beam from the light emitting unit to the light receiving unit is oblique to the end surface of the document table. Detection device. 3. The document size detecting device according to claim 1, wherein the light emitting portion and the light receiving portion of the detecting means have an emission / incident angle of 1 unit.
A document size detection device set at 8-35 degrees. 4. The document size detecting device according to claim 1, wherein the control means is obtained by detecting an output signal from the detecting means obtained by detecting an end face side of the document placing table and detecting an inner side of the end face. A document size detection device that determines a document size based on an output signal and outputs the determination result to a display unit. 5. The document size detecting device according to claim 1, wherein the control means outputs a signal for displaying a result of the document size determination based on an output signal from the detecting means, and then the closing angle detecting means operates. A document size detecting device that resets the display of the result of determination when released, and determines the size of the document based on a signal from the detecting device when the closing angle detecting device is operated again.