JP2001056515A - Open/close detector for original reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the jamming of an original on an original reading position when the original is carried while an upper surface on an original platen is not perfectly closed by an original cover by detecting the open/close state of the upper surface of the original platen by the original cover and deciding whether or not original moving mode is performed. SOLUTION: Light radiated from an exposing lamp 23 is reflected by an original cover plate 10 on the original reading position in the original moving mode, and the reflected light is read by a CCD 26 (photoelectric conversion element). Since the level of the reflected light is changed in accordance with the open/close state and the surface condition of the plate 10, the open/close state of the original cover 4 can be detected by the comparison of a reference lever and a reflected light level. The surface condition such as the soiling of the plate 10, etc., can be grasped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an open / close detecting device for a document reading device for detecting the open / close state of a document conveying unit which can be opened and closed with respect to a document table.

[0002]

2. Description of the Related Art As a document reading device for reading image data to be supplied to an image forming apparatus such as a copying machine from a document, a document fixing mode for reading image data from documents manually placed one by one on a platen upper surface. There is a document reading apparatus which selectively executes a document movement mode for reading image data from a document automatically conveyed to the upper surface of a document table.

In the original fixing mode, the operator of the copying machine operates the original cover in a direction in which the upper surface of the original table is opened,
After placing the original on the exposed upper surface of the original platen, the upper surface of the original platen is closed by the original cover. When the start key is operated in this state, in the document reading apparatus, the scanner unit including the light source and the mirror is moved at a predetermined speed along the lower surface of the document table, and light emitted from the light source is reflected on the image surface of the document. The reflected light is read by the scanner unit as image data of the document.

In the document moving mode, an operator of the copying machine operates a start key after placing a document on a document tray with the document cover closed on the top of the document table. In the document reading device, documents on a document tray are transported one by one into a document transport path. The document conveying path is configured to pass through a document reading position on the upper surface of the document table. In the document moving mode, the scanner unit stops at a position facing the lower surface of the document table at the document reading position. Therefore, the image of the document conveyed in the document conveyance path is read by the scanner unit when passing through the document reading position.

In the original moving mode, in order to accurately read the image of the original at the original reading position, it is necessary to stably transport the original at least at the original reading position.
The document conveying path formed on the upper surface of the document table at the document reading position must be set at an appropriate interval. Therefore, in the document moving mode, the upper surface of the document table must be securely closed by the document cover integrally formed with the document conveying portion of the document reading device.

Therefore, in the conventional document reading apparatus, it is determined whether or not the upper surface of the document table is securely closed by the document cover based on a detection signal of a mechanical or optical sensor provided on the fulcrum side of the document cover. It is determined.

For example, in the configuration disclosed in Japanese Patent Application Laid-Open No. 5-336315, an opening / closing actuator shaft is provided so as to rotate in conjunction with opening / closing of a document cover, and respective actuators of a document detection sensor and a paper size detection sensor are provided. Rotation transmitting means is provided for rotatably holding the opening / closing actuator shaft and transmitting only rotation of the opening / closing actuator shaft in accordance with the opening operation of the document cover to each actuator of the document detection sensor and the paper size detection sensor. . With this configuration, when the document cover is closed, the respective actuators of the document detection sensor and the paper size detection sensor are rotated by the set document, the presence or absence of the document and the size of the document can be detected, and the document cover is opened. When the opening / closing actuator shaft rotates, the respective actuators of the document detection sensor and the paper size detection sensor are rotated thereby, and the opening / closing of the document reading cover can be detected from the output signals of the document detection sensor and the paper size detection sensor. It is possible to omit a detection sensor dedicated to open / close detection, which has been conventionally used, and to provide a document reading apparatus which is inexpensive and effectively uses space.

[0008]

However, a mechanical or optical sensor provided on the fulcrum side of the document cover,
Or, in the conventional method of determining the open / closed state of the upper surface of the original plate by the original cover based on the detection signal of the original size detection sensor for detecting the size of the original on the upper surface of the original plate, the influence of the range position of the sensor, sensitivity, etc. Therefore, even if the document cover is slightly floating from the top of the platen,
There has been a problem that it is erroneously determined that the upper surface of the platen is completely closed. In this case, when the document cover is lifted from the top of the document table, the interval of the document conveyance path at the document reading position is larger than the optimum interval for document conveyance. Is permitted, there is a problem that the document conveyed in the document conveyance path is jammed near the document reading position. In order to solve such a problem, the position of the sensor is changed and the sensitivity is improved. However, the jam of the original in the original moving mode executed in a state where the original cover is slightly opened is described. At present, it is not possible to reliably prevent the occurrence.

SUMMARY OF THE INVENTION An object of the present invention is to change according to the open / close state of the upper surface of a document table by a document cover, and to detect an interval of a document conveying path at a document reading position which causes a document jam. By determining the open / closed state of the upper surface of the original plate by the original cover based on the original document and determining whether or not to execute the original moving mode, the original is conveyed in a state where the upper surface of the original plate is not completely closed by the original cover. It is an object of the present invention to provide a document reading apparatus capable of reliably preventing a document from being jammed at a document reading position caused by the document reading.

[0010]

The present invention has the following arrangement as means for solving the above-mentioned problems.

(1) A document transport section for transporting a document onto a document table, a document pressing plate for pressing a document onto the document table during document transport, and a document reading apparatus for irradiating a document placed on the document table with light. A document reading device that includes a light source and document reading means for reading a document placed on the document table, and detects an open / close state of a document transport unit that can be freely opened and closed with respect to the document table; The document light source is a light source of an open / close detection device that irradiates light to the document holding plate, and the document reading unit is a detection unit that detects an open / closed state of the document conveyance unit according to the amount of reflected light from the document holding plate. .

In this configuration, the open / close state of the document feeder is detected by irradiating light from the document reading light source to the document pressing plate and detecting the amount of reflected light from the document pressing plate by the document reading means. Therefore, since the open / close state of the document feeder is detected by the existing device configuration of the document reading device, it is not necessary to newly add another component.

(2) The detecting means calibrates the detecting means based on the amount of reflected light from a standard reflecting plate provided at a predetermined position, and then moves to a position facing the document pressing plate. It is characterized in that the open / close state of the document feeder is detected.

In this configuration, before detecting the open / closed state of the document feeder, calibration of the document feeder open / close detector is performed. Therefore, the corrected original reading means
The open / closed state of the document feeder is accurately detected.

(3) The document pressing plate reflects light of a hue by which the detecting means can detect the open / closed state of the document feeder.

In this configuration, the light emitted from the light source is reflected by the document pressing plate, and the light reflected by the document pressing plate is a light having a hue capable of detecting the open / closed state of the document conveying unit. Therefore, the document reading section as the detecting means does not read the reflected light of the document pressing plate as an image of the document.

(4) There is provided storage means for storing reference data for judging the open / close state of the document feeder, and the detecting means compares the amount of light reflected by the document pressing plate with the reference data to thereby determine whether the document feeder is open or closed. It is characterized by detecting the open / closed state of.

In this configuration, the open / close state of the document feeder is detected by comparing the reference data stored in the storage means with the amount of reflected light from the document pressing plate. Therefore, even when the document feeder is slightly opened, the open / closed state can be accurately detected by comparing with the reference data.

(5) The storage means stores reference data corrected in accordance with the amount of reflected light from the original pressing plate when the original pressing plate is replaced.

In this configuration, each time the document pressing plate is replaced, the reference data is corrected and stored in the storage means. Therefore, even if the amount of reflected light varies due to variations in the manufacture of the document pressing plate, the open / closed state of the document feeder can be accurately detected.

(6) The reference data is characterized by the amount of light reflected by the original pressing plate in the maximum open state in which the original is conveyed in the original conveying section in a normal state.

In this configuration, the amount of reflected light from the original pressing plate is compared with the maximum open data in which the original is conveyed in the original conveying section in a normal state. Therefore, the appropriateness of the open / close state of the document transport unit is accurately determined based on whether or not the document can be transported normally, and the transport failure such as a paper jam can be determined without lowering the operation efficiency of the document reading light amount. It can be reliably prevented.

(7) The reference data is a reflected light amount of the document pressing plate at a limit value at which the detecting means can determine an open / closed state of the document conveying unit.

In this configuration, the amount of reflected light from the document pressing plate is compared with the limit amount of light that can detect the open / closed state of the document conveying unit. Therefore, if the open / close state of the document feeder cannot be detected, it can be easily determined that the document holding plate cannot reflect a predetermined amount of light due to contamination or the like.

(8) A warning means is provided for issuing a warning when the detection means detects the open state of the document feeder.

In this configuration, when the open state of the document feeder is detected, a warning is issued by the warning means. Therefore, the operator can easily recognize that the document feeder is in the open state.

(9) A warning means is provided for issuing a warning when the detection means cannot detect the open / close state of the document feeder.

In this configuration, if the open state of the document feeder cannot be detected, a warning is issued by the warning means. Therefore, the operator can easily recognize that the original pressing plate cannot reflect a predetermined amount of light due to contamination or the like.

(10) In the document transport section, the document is transported onto a document table after the detecting means detects the closed state of the document transport section.

In this configuration, the document is conveyed for reading the document after the open / close state of the document conveyance unit is detected. Therefore, when the original transport section is securely closed, the original is transported, so that a paper jam of the original does not occur.

[0031]

FIG. 1 is a front sectional view showing the configuration of a document reading apparatus according to an embodiment of the present invention. FIG.
FIG. 3 is a diagram showing a schematic configuration for explaining a document reading operation of the document reading device shown in FIG. 1; FIG. 3 is a front view and a side view showing the appearance of the document pressing plate. FIG.
3 is a right side view of the document reading device shown in FIG.

The original reading device 30 according to this embodiment is
The document table 20 is mounted on the upper surface of the image forming apparatus 40.
A document fixing mode for reading image data from a document manually placed one by one on the upper surface of the document and a document moving mode for reading image data from a document automatically conveyed to the upper surface of the platen glass 22 are selectively executed. .

The document reading device 30 is composed of a document conveying section 31 and a document reading section 32. Document feeder 3
Reference numeral 1 is provided integrally on the upper surface of the document cover 4, and includes a document tray 1, a peak-up roller 7, a paper feed roller 8, a paper feed pad 9, a document feed path 5, a PS (Paper Stop) roller 2,
Document holding plate 10, coil spring 11, transport roller 12,
Reverse conveyance path 6, flapper 15, discharge roller 3, gate 1
4, a reversing tray 13 and a paper discharge tray 16. The document reading unit 32 is disposed on the lower surface of the document table 20 so as to face the document conveying unit 31 inside the image forming apparatus 40, and includes the scanner unit 21, the platen glass 22, and the document table 2
0, a standard white plate 17, and the document cover 4. The scanner unit 21 includes an exposure lamp 23, a first reflection mirror 24a, a second reflection mirror 24b, and a third reflection mirror 24.
c, a lens 25, and a photoelectric conversion element (hereinafter, referred to as a CCD) 26.

The document reading device 30 is rotatable within a predetermined range with the back side as a fulcrum on the upper surface of the image forming device 40. The document cover 4 covers the upper surface of the transparent glass platen 20 provided on the upper surface of the image forming apparatus 40 in an openable and closable manner. The document table 20 has an area corresponding to the maximum document size that can be read by the image forming apparatus 40. A pressing member 4a made of an elastic material and a white film is attached to the lower surface of the document cover 4.
The document cover 4 is rotatable together with the document reading device 30 in a predetermined range with the back side as a fulcrum.

A standard white plate 5 which is a standard reflection plate is provided on the lower surface of the left end of the document table 20. Light emitted from an exposure lamp 23, which is a light source for reading a document, is reflected by a standard white plate 5, and the reflected light is read by a scanner unit 21 to perform shading correction, which is an initial setting of an optical system. Here, the shading correction is a correction for determining the irradiation light amount of the light source and correcting the read value of each pixel of the reading CCD so as to make the received light amount of each pixel constant.
Regarding this shading correction, since various techniques have been conventionally proposed, the details will not be described here. The use of the same standard white plate 5 in the original fixing mode and the original moving mode suppresses an increase in cost.

The document holding plate 10 is opposed to the intermediate portion with a gap provided on the upper surface of the platen glass 22. The document pressing plate 10 is provided for the purpose of smoothly transporting the document on the transport path, and therefore, as shown in FIG. 3, the entire width is wider than the maximum width of the transportable document, and the document pressing plate 10 Bending is performed on the upstream and downstream ends of the transfer so as not to be caught in the shape, and the shape is smooth. The document holding plate 10 is vertically swingable within a predetermined range around the rotation axis of the transport roller 12. The document holding plate 10 is urged downward by the elastic force of the coil spring 11. With this configuration, the gap between the document holding plate 10 and the platen glass 22 changes according to the thickness of the document, and the image surface of the document passing through the document reading position comes into close contact with the upper surface of the platen glass 22. As a result, the image of the document can be accurately read without causing distortion or the like even in the document movement mode.

Referring to FIG. 2, in the document reading device 30, the exposure lamp 23 and the first mirror 24a of the scanner unit 21 of the document reading unit 32 are operated until the document reading operation is performed.
It has moved to a position facing the lower surface of the standard white plate 5, and has stopped at this position. This position is the home position HP
The shading correction, which is the initial setting of the optical system, is performed at this position. In the document moving mode, the exposure lamp 23 and the first mirror 24a of the scanner unit 21 of the image forming apparatus 40 move to a position facing the lower surface of the platen glass 22, and stop at this position. This position is referred to as a home position HP2. At this position, the document holding plate 10 is irradiated with light from the exposure lamp 23, the reflected light reflected by the document holding plate 10 is read by the scanner unit 21, and the open / close state of the document cover 4 is determined. To detect.

The document reading process of the image forming apparatus 40 incorporating the document reading device opening / closing detection device of the present invention will be described. In the original fixing mode, the upper surface of the original table 20 is opened by rotating the front side of the original cover 4 upward, and the original is placed on the upper surface of the original table 20 by manual operation. By rotating
The upper surface of the document table 20 is closed. Thus, the document is fixed in a state where the document is pressed against the upper surface of the document table 20 by the pressing member 4a. When a start key (not shown) is operated in the image forming apparatus 40, shading correction is performed at the home position HP1. Immediately thereafter, the exposure lamp 23, the first mirror 24a, the second mirror 24b, and the third mirror 24c are set in parallel with the platen 20 in the scanner unit 21 disposed on the lower surface of the platen 20 inside the image forming apparatus 40. The document is moved, and the image of the document placed on the upper surface of the document table 20 is scanned by the light of the exposure lamp 23.
The light emitted from the exposure lamp 23 is reflected on the image surface of the original, and the reflected light is reflected by the first mirror 24a and the second mirror 24.
b, CCD via the third mirror 24c and the lens 25
An image is formed on the light receiving surface of the document 26, and the image of the document is read by the CCD 26.

In the document moving mode, when an operator sets a document on the document tray 1 in the image forming apparatus 40 and operates a start key (not shown), the home position HP1 is set.
Performs shading correction. Immediately thereafter, the exposure lamp 23 and the first mirror 24a of the scanner unit 21 of the image forming apparatus 40 move to the home position HP2 and stop at this position. As described above, at the home position HP2, the document holding plate 10 is irradiated with light from the exposure lamp 23, the reflected light reflected by the document holding plate 10 is read by the scanner unit 21, and the document cover 4 is read.
Detects the open / closed state of. When the original cover 4 is closed, the originals set on the original tray 1 are fed out one by one in order from the topmost one by the pickup roller 7 and fed into the original conveying path 5 by the paper feed roller 8. Paper. The PS roller 2 stops rotating between the document feeding timing and the document reading timing in the image forming apparatus 40, and the document fed from the document tray 1 has its front end contacted with the PS roller 2. The document is stopped in the document transport path 5 in the state where the original is moved. The PS roller 2 starts rotating in synchronization with the document reading timing of the image forming apparatus 40, and the document stopped in the document conveying path 5 is constituted by the platen glass 22 disposed on the upper surface of the image forming apparatus 40. The document is conveyed toward the original reading position. As the document passes through the document transport path 5 via the upper surface of the platen glass 22, the image surface of the document is relatively scanned by light emitted from the exposure lamp 23. The reflected light of the light emitted from the exposure lamp 23 on the image surface of the document is transmitted to the CCD 26 via the first mirror 24a, the second mirror 24b, the third mirror 24c, and the lens 25, as in the document fixing mode. An image is formed on the light receiving surface. Thus, the image of the document conveyed in the document conveyance path 5 is read by the CCD 26. The document that has passed through the upper surface of the platen glass 22 is transported by the transport roller 12 in the direction of the discharge roller 3.

The document reading device 30 is compatible not only with a single-sided document having an image surface on one side but also with a double-sided document having an image surface on both front and rear sides. That is, at the time of one-side reading for reading an image of one side of the document, the gate 14 moves upward, and the document fed from the document tray 1 passes through the document reading position and is discharged by the discharge rollers 16 by the discharge rollers 3. Is discharged. During double-sided reading for reading images on both sides of the document, the gate 14 moves downward, and the front end of the document fed from the document tray 1 is moved to the reversing tray 13 by the discharge rollers 3 after passing through the document reading position. After the document is guided and the rear end of the document passes through the flapper 15, the flapper 15 is moved downward, and the paper discharge roller 3 is driven to reverse. As a result, the document is again conveyed to the document reading position via the reversing conveyance path 6 with the front and back surfaces reversed.
The lever 14 and the flapper 15 have been moved upward by the time the front end of the document with its front and back reversed reaches the transport roller 12, and the document whose image reading on both front and back has been completed is
The paper is discharged to the paper discharge tray 16 by the paper discharge roller 3.

Also in the original moving mode, the original is read while the upper surface of the original table 20 is completely closed as shown by the original cover 4a shown by a solid line in FIG. However, when a thick original such as a notebook or a book is placed on the original platen 20 in the original fixed mode and the original is read, and the original placed on the original platen 20 is forgotten, the broken line in FIG. The upper surface of the document table 20 may be slightly opened like the document cover 4b. In this state, when the reading of the document is started, the document pressing plate 10 and the document cover 4 are moved together with the document reading device 3.
0, the original cannot be transported smoothly because the distance between the original pressing plate 10 and the platen glass 22 is wide, and the original transported in the original transport path is located near the original reading position. Jams may occur. Therefore, as described above, at the home position HP2,
The light emitted from the exposure lamp 23 is reflected on the document holding plate 10, and the reflected light is read by the CCD 26 of the scanner unit 21, thereby detecting the open / closed state of the document cover 4.

FIG. 5 is a diagram showing reference data of the reflected light level of the document pressing plate for detecting the open / close state of the document cover. 5A and 5B, the standard reflected light level indicates reference data of the reflected light level of the document pressing plate 10 when the document cover 4 is in the closed state. The surface state of the document holding plate 10 has some variation even in a new state, and the reflected light level is not the same. Therefore, the standard reflected light level is data that is corrected every time the document pressing plate 10 is replaced.

The reference reflected light level LV1, like the standard reflected light level, is reference data indicating that the document cover 12 is in the closed state. This data is the minimum reflected light that is conveyed in a normal state of the document. Indicates a level. Specifically, if the reflected light level of the document pressing plate 10 is equal to or higher than the reference reflected light level LV1 and equal to or lower than the standard reflected light level, it means that the original can be conveyed normally. By setting the reference reflected light level LV1 in this manner, even if the document cover 12 is slightly floating, the document can be conveyed if it does not affect the conveyance of the document.

The reference reflected light level LV2 is different from the data of the standard reflected light level and the reference reflected light level LV1, and is reference data indicating the surface state of the document pressing plate 10. That is, due to repeated conveyance of the original, the original pressing plate 1
When the scratches, dirt, dust, and the like adhere to the surface of the document 0, there is a possibility that the reflected light level of the document pressing plate 10 locally decreases. Thus, the reference reflected light level LV, which is reference data of a limit value at which the open / close state of the document cover 4 can be determined.
By providing 2, the state of the surface of the document holding plate 10 can be grasped, and if the surface of the document holding plate 10 cannot be determined to be opened or closed due to abrasion or dirt,
Cleaning or replacement can be prompted to the operator.

An example of determining the open / closed state of the document cover 4 and the surface state of the document pressing plate 10 based on the level of reflected light from the document pressing plate 10 will be described below. In the case of the state of the document cover 4a in FIG. 4, the state shown in the reflected light level A in FIG. That is, the reflected light level of the document pressing plate 10 is equal to or higher than the reference reflected light level LV1 and equal to or lower than the standard reflected light level. Therefore, it is determined that the document cover 4 is in the closed state, and the document is conveyed normally.

In the case of the state of the document cover 4b in FIG. 4, the state shown in the reflected light level B in FIG.
That is, a part of the reflected light level of the document holding plate 10 is equal to or higher than the reference reflected light level LV1 and equal to or lower than the standard reflected light level, and a part is equal to or lower than the reference reflected light level LV1 and equal to or higher than the reference reflected light level LV2. Therefore, it is determined that the document cover 4 is open, and the conveyance of the document is stopped.

The reflected light level C in FIG. 5B is equal to or lower than the reflected light level 1 and equal to or higher than the reference reflected light level LV2. Therefore, it is determined that the document cover 4 is open, and the conveyance of the document is stopped. In the case of the reflected light level C, the document cover 4 is more open than in the case of the reflected light level B.

The reflected light level D shown in FIG. 5B indicates that although the original cover 4 is not opened, dust adheres to a part of the surface of the original pressing plate 10, or a part of the surface Indicates that light cannot be reflected normally due to missing. In addition, the reflected light level E can be determined because the surface of the document pressing plate 10 is soiled due to friction with the document and the like, and a part of the reflected light level is lower than the reference reflected light level LV2. Indicates that it is gone. In these cases, cleaning the surface of the document holding plate 10 makes the surface clean and reusable. If the surface of the document holding plate 10 is not cleaned even after cleaning, replace the document holding plate 10 with a new one. At this time, the reflected light level of the new document pressing plate 10 is confirmed, and the standard reflected light level is corrected.

When the document holding plate 10 is slightly contaminated as a whole, even if the document cover 4 is closed, the state of the reflected light level C is such that the document cover 4 is open. Is determined, and the conveyance of the document may be stopped. In this case, the erroneous detection can be eliminated by cleaning the surface of the document holding plate 10 or replacing the document holding plate 10 with a new one.

In order to more reliably detect the open state of the document cover 4, the hue of the document pressing plate 10 is
It is desirable to use a hue such as white, which reflects light of a hue that makes it easy to determine the amount of light received at 26. If the hue of the document holding plate 10 is a hue in which it is difficult to determine the data received by the CCD 26, image processing or the like must be performed, and the processing becomes complicated.

FIG. 6 is a block diagram showing the configuration of the control section of the document reading device 30. The control unit 50 of the document reading device 30 is a CPU 5 having a ROM 52 and a RAM 53.
1, a master CP constituting a control unit of the image forming apparatus 40
U61, CCD 26, memory 27, motor 54, clutches 55 to 57, and solenoids 58 and 59 are connected. The CPU 51 compares the data input from the master CPU 61 with the reference value of the reflected light level stored in the memory 27 according to the reflected light level detected by the CCD 26, and according to a program pre-written in the ROM 52. , Motor 54, clutch 55 to 5
7 and the solenoids 58 and 59 are driven. The motor 54 generates a rotation to be supplied to the PS roller 2, the paper discharge roller 3, the pickup roller 7, the paper feed roller 8, and the transport roller 12. The clutches 55 and 56 are
Is selectively transmitted to the PS roller 2 and the pickup roller 7. The clutch 57 selectively transmits the rotation of the motor 54 to the discharge roller 3 in either the forward or reverse direction.
The solenoids 58 and 59 are connected to the gate 14 and the flapper 1
Swing 5 The memory 27 is a rewritable nonvolatile memory such as an EPROM.

FIG. 7 is a flowchart showing a processing procedure in which the control unit of the document reading device 30 detects the open / closed state of the document cover 4 in the document moving mode.

The operator sets a document on the document tray 1 (s1), and inputs printing conditions such as print density on an operation panel (not shown) of the image forming apparatus 40 (s2). An original reading process and a printing process are started by operating a start key 40 outside the figure (s3). The CPU 51
At home position HP1 shown in FIG. 2, light reflected from exposure lamp 23 and reflected by standard white plate 5 is read by CCD 26 of scanner unit 21 to perform shading correction, which is an initial setting of the optical system (s).
4). After the optical system is initialized by shading correction, the CPU 51 moves the scanner unit 21 to the home position HP2 shown in FIG. 2 (s5), and irradiates from the exposure lamp 23 and reflects the light reflected by the document pressing plate 10. The light is read by the CCD 26 of the scanner unit 21,
The reflected light level is detected (s6).

As described with reference to FIG. 5, if there is no gap between the document cover 4 and the document table 20, the reflected light level of the read document pressing plate 10 shows a normal value. If there is a gap between the document cover 4 and the platen 20, the document pressing plate 1
The reflected light level of 0 is affected by the illuminance around the image forming apparatus 40, and no normal value is detected. Therefore, the open / closed state of the document cover 4 can be detected by detecting the reflected light level of the document pressing plate 10 before reading the document. More specifically, the reflected light level of the document pressing plate 10 detected by the CCD 26 is stored in the memory 2.
If the level is equal to or higher than the reference reflected light level LV1 stored in the document 7 (s7), the CPU 51 determines that the document cover 4 is not opened, and starts transporting the document placed on the document table 1 (s8). Then, the CPU 51 causes the scanner unit 21 to read the document, and the master CPU 61 performs a printing process of the read document image (s9). It is determined whether or not to print the next document (s10).
The document is conveyed (s8), and the printing process is executed (s8).
9). If there is no document to be printed next (s10), the printing process ends.

If the reflected light level of the original pressing plate 10 detected by the CCD 26 is lower than the reference reflected light level LV1 stored in the memory 27 (s7), the reference reflected light level LV2 stored in the memory 27 is used. Compared to
If it is equal to or higher than the reference reflected light level LV2 (s11), CP
U51 indicates that the upper surface of the document table 20 is open or
The document cover 4 is raised from the upper surface of the image forming apparatus 40, a message indicating that it is determined that the document cover 4 is not in a state suitable for the operation in the document moving mode, and that it is necessary to confirm that the document has not been removed from the platen 20. Is displayed (s4). This message is performed, for example, on a display unit (not shown) of the image forming apparatus 40. When the image forming apparatus 40 includes a voice synthesizing unit and a speaker, the message may be reproduced by voice.

The operator confirms that he or she has forgotten to take the original, closes the original plate 20 securely with the original cover 4 (s13), and presses a start key (not shown) of the image forming apparatus 40 (s3).
The CPU 51 performs the shading correction again, and executes s4
The following processing is performed.

Further, the reflected light level of the original pressing plate 10 detected by the CCD 26 is compared with the reference reflected light level LV2 stored in the memory 27. If the reflected light level is lower than the reference reflected light level LV2 (s11), the CPU 51 proceeds to step S11. It is determined that dust is attached to the surface of the document holding plate 10, a part thereof is missing or dirty, and the surface of the document holding plate 10 is cleaned or the document holding plate 10 is replaced. Display the message as described above (s1
4).

When replacing the document holding plate 10 (s1
5) The operator replaces the original pressing plate 10 with a new one, irradiates the original pressing plate 10 with light from the exposure lamp 23, and corrects the standard reflected light level stored in the memory 27 (s16). Then, input of print conditions such as print density is performed again on an operation panel (not shown) of the image forming apparatus 40 (s2), and a start key (not shown) of the image forming apparatus 40 is operated to read a document and perform a printing process. Start (s
3).

When the operator does not replace the original presser plate 10 because the original presser plate 10 is out of stock, the user carries out an operation for performing a printing process on an operation panel (not shown). s15). In this case, the CPU 51 determines that the document cover 4 has not been opened, and starts transporting the document placed on the document table 1 (s8). And CP
U51 causes the scanner unit 21 to read the document, and the master CPU 61 performs the printing process of the read document image (s9). It is determined whether or not the next document is to be printed (s10). When printing, the document is conveyed (s10).
8), a printing step is performed (s9). If there is no original to be printed next, the printing process ends.

As described above, the original is always read normally unless the operator forcibly performs the original reading operation. Therefore, the CPU 51 determines whether the original cover 4 is open or closed or the original pressing plate. After confirming the state of 10, the document is started to be conveyed, the document image is read, and the document image is printed.

According to the above processing, when the document moving mode for the document set on the document tray 1 is started, the light emitted from the exposure lamp 23 to the document pressing plate 10 is reflected, and the reflected light is By causing the CCD 26 to read, the upper surface of the document table 20 is placed on the document cover 4.
To determine whether it is completely closed or not,
Only when the upper surface of the platen 20 is completely closed,
The document moving mode is executed. Therefore, the upper surface of the document table 20 is closed in an incomplete state, such as a state in which the document reading device 30 rises from the upper surface of the image forming device 40, and the guide is provided at the document reading position where the platen glass 22 is disposed. In a situation in which the document cannot be securely brought into close contact with the upper surface of the platen glass 22 by the plate 10, the document moving mode is not executed, and it is possible to reliably prevent image reading failure and document jam. . Even in such a situation, the copy operation in the original fixed mode is not restricted at all, so that, for example, a thick original such as a book can be copied without any trouble.

The configuration of the document reading device mounted on the upper surface of the image forming apparatus 40 does not necessarily have to be as described. For example, a document reading device that reads only one side of a document may be used. Further, the opening / closing detection device has been described by taking a document reading device mounted on the upper surface of the image forming apparatus 40 as an example. However, the present invention is not limited to this configuration. The opening / closing detection device having the configuration of the present invention can be implemented in a document reading device or the like connected to a computer, a printer, or the like.

[0063]

According to the present invention, the following effects can be obtained.

(1) The original reading light source irradiates the original pressing plate with light, the amount of reflected light from the original pressing plate is detected by the original reading means, and the open / closed state of the original conveying section is detected.
Since the open / close state of the document feeder is detected by the existing device configuration of the document reading device, it is not necessary to add another component. In addition, it is possible to prevent a document conveyance error.

(2) Before detecting the open / closed state of the document feeder, the open / closed state of the document feeder can be accurately detected by the corrected document reading means by calibrating the open / closed detector of the document feeder. Is done.

(3) The light emitted from the light source is reflected by the document pressing plate, and the light reflected by the document pressing plate is light of a hue capable of detecting the open / closed state of the document conveying unit.
The document reading section, which is the detecting means, does not read the reflected light from the document pressing plate as an image on the document and detects the open / closed state by easily detecting the reflected light at the document reading section without performing image processing or the like. Thus, the state of the document pressing plate can be quickly recognized.

(4) The reference data stored in the storage means,
By detecting the open / closed state of the document feeder by comparing the amount of light reflected from the document holding plate, even if the document feeder is slightly open, the open / closed state can be accurately detected by comparing with the reference data. Open / close detection can be realized quickly and inexpensively.

(5) The reference data is corrected and stored in the storage means each time the document pressing plate is replaced, so that even if the amount of reflected light varies due to variations in the manufacturing of the document pressing plate, the opening and closing of the document conveying unit can be performed. The condition is accurately detected.

(6) By comparing the amount of reflected light from the original pressing plate with the maximum open state data in which the original is conveyed in a normal state in the original conveying section, the suitability of the open / close state of the original conveying section can be determined. It is accurately determined based on whether or not the document can be conveyed normally, and it is possible to reliably prevent a conveyance failure such as a paper jam without lowering the operation efficiency of the original reading light amount. In addition, the reference data stored in the storage means allows the original to be transported to the minimum open state of the original cover, so that the original can be moved in the original moving mode while the original is placed on the original platen. If the original is scanned by the scanner or if the original cover is warped due to its life, etc., and there is no problem in performing the original transfer mode, the original can be conveyed without any problem, resulting in poor usability. Thus, it is possible to realize the detection of the opening / closing of the document cover.

(7) If the open / closed state of the document feeder cannot be detected by comparing the amount of reflected light from the document presser with the limit light amount that can detect the open / closed state of the document feeder, the document presser becomes dirty. Thus, it can be easily determined that the predetermined amount of light cannot be reflected. Further, since the scratches and dirt on the document holding plate can be detected based on the reference data stored in the storage means, the life of the document holding plate can be automatically recognized.

(8) When the open state of the document feeder is detected, a warning is issued by the warning means, so that the operator can easily recognize that the document feeder is open, and useless printing and It is possible to prevent the document from being damaged due to the document conveyance abnormality.

(9) If the open state of the document feeder cannot be detected, a warning is issued by the warning means, so that the operator can easily confirm that the document holding plate cannot reflect the predetermined amount of light due to contamination or the like. It can be recognized, and the maintainability of the document reading device is improved.

(10) The original is transported for reading the original after the open / close state of the original transport is detected, so that the original is transported when the original transport is securely closed. Therefore, paper jam of the document does not occur.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a configuration of a document reading apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of the document reading apparatus.

FIGS. 3A and 3B are a front view and a side view showing the appearance of a document pressing plate. FIGS.

FIG. 4 is a right side view of the document reading device.

FIG. 5 is a diagram showing reference data to be compared with a reflected light level of a document pressing plate.

FIG. 6 is a block diagram showing a configuration of a control unit of the document reading device 30.

FIG. 7 is a flowchart illustrating a processing procedure for detecting the open / closed state of the document cover.

[Explanation of symbols]

 4-document cover 10-document holding plate 23-exposure lamp 26-CCD

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H012 CB12 CB29 CD06 5C062 AB17 AB29 AB42 AC58 AD02 AF15 5C072 AA01 BA13 CA02 EA05 LA02 LA07 LA18 MB06 RA16 UA02 UA11 XA01

Claims (10)

[Claims] A document feeder for feeding a document onto a document table; a document holding plate for pressing the document onto the document table during document transfer; and a document reading light source for irradiating the document placed on the document table with light. And an original reading means for reading an original placed on the original platen, and an open / close detecting device of the original reading device for detecting an open / close state of an original conveying unit which can be opened and closed with respect to the original platen. The document is characterized in that the light source is a light source of an opening / closing detection device that irradiates light to the document holding plate, and the document reading unit is a detection unit that detects the open / close state of the document feeding unit according to the amount of reflected light from the document holding plate. An open / close detector for the reader. 2. The method according to claim 1, wherein the detecting unit corrects the detecting unit based on a reflected light amount of a standard reflecting plate provided at a predetermined position, and then moves to a position facing the document pressing plate, 2. The opening / closing detection device for a document reading device according to claim 1, wherein the opening / closing state of the document conveyance unit is detected. 3. The document reading apparatus according to claim 1, wherein the document pressing plate reflects light of a hue by which the detection unit can detect an open / closed state of the document conveying unit. Detection device. 4. A storage means for storing reference data for judging the open / close state of the document feeder, wherein the detector compares the amount of light reflected by the document pressing plate with the reference data to determine the open / close state of the document feeder. 4. The open / close detecting device for a document reading device according to claim 1, wherein the open / close state is detected. 5. The storage device according to claim 4, wherein the storage unit stores, when the document pressing plate is replaced, reference data corrected in accordance with the amount of reflected light from the document pressing plate.
2. The open / close detection device for a document reading device according to claim 1. 6. The reference data according to claim 4, wherein the reference data is a reflected light amount of a document pressing plate in a maximum open state in which the document is conveyed in a normal state in the document conveying section. Open / close detection device of the original reading device. 7. The document according to claim 4, wherein the reference data is a reflected light amount of a document pressing plate at a limit value at which the detection unit can determine an open / close state of the document conveyance unit. An open / close detector for the reader. 8. The document reading apparatus according to claim 1, wherein said detecting means includes a warning means for issuing a warning when detecting an open state of said document conveying section. Open / close detection device. 9. The document reading apparatus according to claim 1, further comprising: a warning unit that issues a warning when the detection unit cannot detect the open / close state of the document conveyance unit. Open / close detection device. 10. The document conveying section according to claim 1, wherein the document conveying section conveys the document onto a document table after the detecting section detects a closed state of the document conveying section. An opening / closing detection device for the document reading device according to the above.