JP2020196553A - Manuscript feeder and image reader - Google Patents

Abstract

To provide an automatic manuscript feeder capable of preventing breakage to a manuscript by detecting stitched manuscripts and stopping sheet feeding regardless of a state before sheet feeding.SOLUTION: The manuscript feeder includes: a manuscript loading part 101 for loading a manuscript; a manuscript feeding part comprised of a feeding roller 103, a separation conveyance roller 104 and a separation conveyance driven roller 105 for delivering the manuscript on the manuscript loading part to an image reading position; a feeding frame 190 arranged to guide the sheet conveyed by the feeding means; and manuscript height detection means S4 for detecting a height of the top sheet loaded on a loading surface. An upward guide shape has a wider space as it moves more toward the outside.SELECTED DRAWING: Figure 1

Description

The present invention relates to a document feeding device that separates and feeds documents placed on a platen one by one.

Conventionally, as an image reading device mounted on a copier or the like, an automatic document feeding device that separates and feeds documents placed on a document table one by one is used.

With the automatic document feeder as described above, the stapled document and the glued document, the so-called "bound document", cannot be normally separated and fed, and the documents of the automatic document feeder are separated. In the mechanism, the document may be wrinkled or torn. Further, if the bound originals are transported without being separated, they may cause clogging on the transport path.

Therefore, there is a device having a configuration for determining the presence or absence of a bound original by shielding the sensor from both sides of the original in the width direction of the original by the floating of the original when the bound original is fed. Further, by arranging a plurality of sensors side by side so as to be perpendicular to the document surface, it is possible to detect the height of the float when the bound document is fed and determine the presence or absence of the bound document. In addition, in that configuration, if there is a float before paper feeding, the height before paper feeding is added to the originally detected height to deal with the float before paper feeding. Can be detected. (See Patent Document 1).

Japanese Unexamined Patent Publication No. 2008-007280

However, in the configuration using the sensors from both sides, when the detection corresponding to the float before feeding is performed, the height to be detected is determined by the float closest to the sensor. Therefore, there is a problem that when a bound document is fed, if a place other than the one that floated before feeding is floated, it is determined that the floating amount does not exceed a predetermined amount and the bound document cannot be detected.

Therefore, an object of the present invention is to provide an automatic document feeding device capable of detecting a bound document, stopping the feeding, and preventing damage to the document regardless of the state before feeding.

In order to achieve the above object, the document feeding device according to the present invention is
It was conveyed by the document feeding unit including a document loading section for loading documents, a paper feeding roller / separation transport roller for feeding the document on the document loading section to an image reading position, and a separation transport driven roller, and the feeding means. It has a paper feed frame arranged so as to guide the sheets, and a document height detecting means for detecting the height of the highest sheet loaded on the loading surface, and the upper guide shape is the feeding. The feature is that the space becomes wider from the means to the outside.

According to the document feeding device according to the present invention, the bound document can be detected regardless of the state of the document before feeding the document, the document can be prevented from being damaged, and the usability of the image reading device is improved. It becomes possible.

Overall schematic view which shows the printer which concerns on 1st Embodiment Side view showing the height detection sensor (A) Schematic diagram showing a height detection sensor that is close to the document surface, (b) Schematic diagram showing a height detection sensor that is far from the document surface, (c) Between the document surface and the height detection sensor Graph showing the relationship between the distance between and the sensor output Explanatory drawing explaining that the bound document is floated Schematic diagram showing the shape of the paper feed frame Schematic diagram showing the relationship between the paper feed frame and the floating document when the bound document is fed. Schematic diagram showing the arrangement of the paper feed frame and the height detecting means The control block diagram according to the first embodiment Flowchart showing copy operation when bound original is fed (A) A view of a normal document to be fed from the width direction, and (b) a view of a bound document to be fed from the width direction. (A) Graph showing the output of the height detection sensor while feeding a normal document, (b) Graph showing the output of the height detection sensor while feeding a bound document. Side view which shows the height detection sensor which concerns on 4th Embodiment Perspective view showing the height detection sensor

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

In FIGS. 1 and 2, 100 is an automatic document transfer device. Reference numeral 101 is a document tray, and the document 102 is loaded by the user. A tray document presence / absence sensor S1 is arranged on the document tray 101 to detect whether the document 102 is loaded at a position where paper can be fed. A paper feed roller 103 is provided downstream of the document tray 101. The paper feed roller 103 is rotated by the paper feed motor M1 together with the separate transfer roller 104 to feed paper.

The paper feed roller 103 is normally retracted to an upper position, which is the home position, so as not to interfere with the document setting operation. When the paper feeding operation is started, the paper feeding roller 103 descends and comes into contact with the upper surface of the document 102. Since the paper feed roller 103 is pivotally supported by the arm 151, the paper feed roller 103 moves up and down as the arm swings.

The separation transfer driven roller 105 is arranged on the opposite side of the separation transfer roller 104, and is pressed against the separation transfer roller 104 side. The separate transfer driven roller 105 is formed of a rubber material or the like having slightly less friction than the separate transfer roller 104, and cooperates with the separate transfer roller 104 to produce one original document 102 fed by the paper feed roller 103. Separate and feed the paper one by one.

The separated sensor S2 is a sensor that detects the timing at which the document 102 passes through the separate transfer driven roller 105 and the separate transfer roller 104.

The resist roller 106 and the resist driven roller 107 align the tips of the documents fed by the separation section, and abut the tips of the separated documents toward the nip portions of the stationary resist roller 106 and the resist driven roller 107. , Create a loop in the document and align its tips. When the tips are aligned, the original is conveyed by the resist roller 106 and the resist driven roller 107. Then, the lead roller 108 and the lead driven roller 109 convey the document toward the scanning glass 116. A platen guide roller 110 is arranged on the opposite side of the scanning glass 116.

At this time, the image information on the surface of the document 102 passing over the scanning glass 116 is read by the CCD line sensor 126. The lead ejection roller 111 and the lead ejection driven roller 112 convey the document to the paper ejection roller 113 side. 117 is a jumping platform for scooping up the sheet from the scanning glass 116. The paper ejection roller 113 ejects the original to the paper ejection tray 114.

The resist roller 106, the lead roller 108, the lead discharge roller 111, and the paper discharge roller 113 are rotated by the transfer motor M2.

S4 is a document lift detection sensor installed on the upper part of the paper feed tray 101. Reference numeral 115 denotes an image reading device. The image reader 115 includes a lamp 119 that irradiates the surface of the scanned document with light, and a mirror 120 that guides the reflected light from the document 102 to the lens 125 and the CCD line sensor 126. The lamp 119 and the mirror 120 are attached to the carriage 123.

The carriage 123 is connected to the drive motor M3 by a timing belt 128, and moves in parallel with the platen glass 118 by the rotation of the drive motor M3. The diffused light from the document is guided to the lens 125 via the mirror 120, and is imaged on the light receiving portion of the CCD line sensor 126 by the lens 125. The CCD line sensor 126 photoelectrically converts the imaged reflected light with a light receiving element, and outputs an electric signal according to the amount of incident light.

FIG. 2 is a view of the arrangement of the document surface height detection sensor S4, the document 102, the paper feed roller 103, and the separate transfer roller 104 as viewed from the side in the horizontal direction with respect to the paper feed direction of the loaded document.

As shown in FIG. 2, the document surface height detection sensor S4 is installed on the upper part of the document surface, and measures the distance between the document surface height detection sensor S4 and the document surface loaded on the loading unit.

FIG. 3 is a diagram showing the input / output relationship of the document surface height detection sensor S4.

The document surface height detection sensor S4 includes a light emitting unit and a light receiving unit, and the light emitted from the light emitting unit of the document surface height detection sensor S4 is reflected on the document surface, and the light receiving unit of the document surface height detection sensor S4. Is received at. At this time, when the document surface is high as in the case of FIG. 3A, that is, when the distance between the document surface and the document surface height detection sensor S4 is short, the light flux reflected on the document surface is detected by the document surface height detection sensor S4. Since a large amount of light can be captured by the light receiving portion of the light receiving part, the amount of received light becomes large. On the other hand, when the document surface is low as shown in FIG. 3B, that is, when the distance between the document surface and the document surface height detection sensor S4 is long, the light flux reflected by the document surface is collected by the document surface height detection sensor S4. The light receiving part cannot capture a large amount, and the amount of received light becomes small. Therefore, as shown in FIG. 3C, the output of the document surface height detection sensor S4 is determined according to the distance. The bound document can be detected by setting the height to be detected with respect to the characteristic floating when the bound document is fed.

Here, consider a case where the document 102 is loaded as shown in FIG. 4A and the corners of the tips of the first and second sheets of the document are bound by the staple ST. At this time, the first sheet of the bound original is fed one by one by the paper feed roller 103 and the separation transfer roller 104 as usual. However, as shown in FIG. 4B, the second sheet of paper is stopped by the separate transfer driven roller 105. Then, as shown in FIG. 4C, the entire paper of the first sheet advances in the paper feeding direction, whereas the paper near the staple ST is stopped together with the second sheet, so that there is excess paper in the vicinity. become. This remainder becomes floating and appears when the bound document is fed.

The upper limit of the floating shape of this document is determined by the guide shape. When the document is further transported, the waist is crushed by the guide as in 4 (d), and the document changes to a second float.

FIG. 5 describes a paper feed frame 190, which is a feature of the embodiment.

As shown in FIG. 5A, the paper feed frame 190 is a guide member for guiding the originals when the originals loaded on the original tray 101 are fed separately and conveyed, and the guide shape has a paper feed roller. It is characterized in that the space increases from the vicinity of 104 to the upstream direction and from the main scanning center to the outside. As shown in FIGS. 5 (a) to 5 (c), the space becomes wider from the cross section AA to the cross section CC.

FIG. 6 shows a state in which a float of the original document is formed in the guide shape shown in FIG. 5, and the float is formed in a shape along the guide shape. Therefore, since it is possible to create a floating document at a desired position depending on the guide shape, the document height detection sensor S4 is arranged at a position where the floating amount of the document is the largest as shown in FIG. In order to detect the front-binding document and the back-binding document, one document height detection sensor S4 is arranged on each of the front side and the back side of the paper feed roller 103.

FIG. 8 is a functional block diagram of the present embodiment.

In FIG. 8, the CPU 403 determines whether or not the document is a bound document according to the output from the document surface height detection sensor S4. Further, according to the determination result, the paper feed motor M1 transport motor M2 and the read motor M3 are controlled via the motor control unit 402, and the paper feed roller 103 and the separate transport roller 104 are controlled. The threshold value of the document surface height detection sensor S4 is stored in the memory 401.

Next, a method of detecting a bound document bound by staples or the like will be described with reference to FIGS. 9, 10 and 11.

FIG. 9 is a diagram showing a flowchart relating to binding document detection in this embodiment.

The flowchart is controlled by the CPU 403 of FIG.

FIG. 10A is a view of the normal paper feeding status as viewed from the side in the horizontal direction with respect to the feeding direction. FIG. 10B is a view of the paper feed status of the bound document as viewed from the side in the horizontal direction with respect to the paper feed direction. FIG. 11A shows the output of the document surface height detection sensor S4 when the normal document is fed, and FIG. 11B is a diagram showing the output of the document surface height detection sensor S4 when the bound document is fed.

First, in step S601, it is determined whether or not the document 102 is loaded on the document tray 101.

In the following step S602, when a copy start instruction is given from an operation unit (operation panel) (not shown) with the document 102 loaded, the process proceeds to step S603 and the loaded document is fed. When the paper feeding is started, the process proceeds to step S604 and the output value of the document surface height detection sensor S4 is read.

Subsequently, in step S605, it is determined whether or not the value read in step S604 exceeds the detection threshold value of S4 stored in advance in the memory 401. At this time, as shown in FIG. 10A, when a normal document is fed to the document loading section, the paper feed document does not float, as in FIG. 11A, when the normal document is fed. The output of the document surface height detection sensor S4 is in a low state. Therefore, when the normal document is fed, the detection threshold value is not exceeded in step S605, and it is determined that the normal document is fed. In the case of normal document feeding, it is determined in step S606 whether the paper feed is the final document. If it is not the final document, paper feeding is continued, and if it is the final document, the process proceeds to step S607 to stop the paper feeding motor M1 and the transport motor M2, stop the paper feed motor M1 and the transport motor M2, and supply the paper. Stop the paper and end the operation.

Next, as shown in FIG. 10B, when the bound original is fed, the original is floated and the original surface is raised. At this time, if the detection threshold value set as in the case of feeding the bound document in FIG. 11B is exceeded, it is determined in step S605 that the bound document is bound. When it is determined that the document is bound, the process proceeds to step S607, the paper feed motor M1 and the transport motor M2 are stopped, the paper feed motor M1 and the transport motor M2 are stopped, the paper feed is stopped, and the operation is terminated.

In the present embodiment, when the bound original is fed, the height of the original surface is measured by measuring the height of the original surface by the amount of reflected light, so that the bound original can be detected with high accuracy. It is possible to stop feeding paper quickly and prevent damage to the original.

Next, a second embodiment of the present invention will be described, but the second embodiment differs from the first embodiment only in the configuration of the height detection sensor. Therefore, the same configuration as that of the first embodiment will be described by omitting the illustration or adding the same reference numerals to the drawings.

As shown in FIGS. 12A and 13, the paper feed frame 190 of the ADF 150 is provided with a height detection sensor 130. Similar to the height detection sensor S4 of the first embodiment, the height detection sensor 130 is arranged so as to overlap the loading surface when viewed from the height direction orthogonal to the loading surface of the document tray 101.

The lever document contact portion 96a of the lever 96 is arranged in the height detecting means arrangement range portion as shown in FIG.

As shown in FIG. 13, the height detection sensor 130 includes a lever 96 as a moving unit that rotates following the top-level document loaded on the document tray 101, and an encoder that detects the rotation angle of the lever 96. The rotary volume 99 and the like are provided. The first gear 98 is rotatably connected to the rotary volume 99, and the second gear 97 is meshed with the first gear 98. The second gear 97 is fixed to the shaft 95, and the lever 96 is fixed to the shaft 95. Therefore, when the lever 96 rotates following the uppermost document, the electrical resistance of the rotary volume changes, and the voltage detected by the CPU 81 changes. By this change in voltage, the height position of the top-level document can be detected. That is, the height detection sensor 130 transmits a signal based on the magnitude of the rotation angle of the lever 96 to the CPU 81.

As shown in FIG. 13B, when the top-level document of the bound document bound by the staple ST is fed by the paper feed roller 103, the top-level document is lifted and the height of the document is high. The position is partially raised. Since the lever 96 of the height detection sensor 130 is in contact with the upper surface of the document, the lever 96 rotates upward as the document floats. Then, when the height position of the document detected by the height detection sensor 130 based on the position of the lever 96 exceeds a predetermined threshold value, the CPU 81 determines that the document being fed is a bound document.

As described above, in the present embodiment, the height position of the document is detected according to the rotation angle of the lever, not the amount of the reflected light from the document. Therefore, the height position of the document can be stably detected regardless of the paper type and the basis weight of the document.

In the second embodiment, the height position of the document is detected by the lever 96 that is rotatably supported and the rotary volume 99 that detects the rotation angle of the lever 96, but the present invention is not limited to this. That is, the lever is not limited to the rotatable lever, and any lever may be used as long as it detects the height position of the document based on the position of the moving portion that moves following the top-level document. For example, the height position of the document may be detected by detecting the position of the float that abuts on the upper surface of the top-level document.

In any of the above-described forms, the description has been made using an electrophotographic printer, but the present invention is not limited thereto. For example, the present invention can be applied to an inkjet type image forming apparatus that forms an image on a sheet by ejecting an ink liquid from a nozzle.

101 Document loading section, 103 Paper feed roller, 104 Separation transfer roller,
105 Separation and Conveyance Driven Roller, 190 Paper Feed Frame, S4 Document Height Detection Means

Claims (5)

The document loading section for loading documents and
A document feeding unit including a paper feed roller, a separation transfer roller, and a separation transfer driven roller that feeds the document on the document loading unit to the image reading position.
A paper feed frame arranged to guide the sheets transported by the feeding means, and
Document height detecting means for detecting the height of the top sheet loaded on the loading surface, and
Have,
A document feeding device in which the upper guide shape sandwiches the feeding means and at least one place on the front side or the back side widens the space from the feeding means toward the upstream side and the outside in the cross section. The first aspect of claim 1, wherein the upper guide shape has two spaces on the front side and the back side of the feeding means, which are wider on the upstream side and outward in the cross section from the feeding means. Document feeding device. The document feeding device according to claim 1, wherein the document height detecting means is arranged at a place having the largest space in the main scanning cross section of the upper guide. The document feeding device according to claim 3, wherein the document height detecting means is arranged downstream of the paper feed roller. The document feeding device according to claim 3, wherein the document height detecting means is arranged in the vicinity of the separation and conveying roller.