JP2011105418A - Sheet thickness discriminating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet thickness discriminating device capable of discriminating sheet thickness in a simple constitution. <P>SOLUTION: The sheet thickness discriminating device includes a guide 50 for guiding the fore end of a sheet P between conveying rollers, the pair of conveying rollers for conveying the sheet guided from the guide in the predetermined direction, and a detection means 60 for detecting the fore end of the sheet. Two or more conveying rollers are arranged on the axis. The detection means 60 is arranged on the upstream side to which the sheet P is conveyed and in a vicinity of the position at which the conveying rollers are brought into contact with each other, or on the upstream side to which the sheet P is conveyed, and in a vicinity of the position at which the conveying rollers are brought into contact with each other via the sheet P. The detection means 60 discriminates the thickness of the sheet P according to the result of detection of the fore end of the sheet P when the sheet is butted on the pair of conveying rollers. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a sheet thickness discrimination device.

  As a configuration of an apparatus for discriminating the thickness of a sheet, there is one as disclosed in Patent Document 1. The configuration of this patent document measures the value of a current flowing through a motor when a sheet is conveyed by a loop forming roller and the leading edge of the sheet is abutted against a registration roller.

JP 2004-18127 A

  However, the configuration measures the current flowing through the motor, and there are variations in the measured value and the thickness of the paper, so it was necessary to take a large amount of sampling of the measured value.

In order to solve the above-described problems, the present invention provides a guide for guiding the leading edge of a sheet between conveyance rollers, a pair of conveyance rollers for conveying a sheet guided from the guide in a predetermined direction, and a pair of conveyance rollers. Detecting means for detecting the leading edge of the sheet,
Two or more of each conveyance roller is arranged on the axis, and the detection means conveys the sheet on the upper side of the river and near the position where the conveyance rollers contact each other, or on the upper side of the river on which the sheet is conveyed and via the sheet. It is arranged in the vicinity of the position where the rollers come into contact with each other, and the detecting means determines the thickness of the sheet based on the detection result of the leading edge of the sheet when abutting against the pair of conveying rollers.

  The invention according to claim 2 is characterized in that a sheet passage detecting means for detecting passage of the sheet is arranged on a side of the detecting means on which the sheet is conveyed. Further, in the invention described in claim 3, the guide gradually narrows toward the conveyance roller, and regulates the conveyance of the sheet having a thickness greater than or equal to the introduction portion that smoothly conveys the sheet to the conveyance roller side. And a restricting portion.

  With the above configuration, according to the present invention, the thickness of the sheet can be determined with a simple configuration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of an image reading apparatus to which the sheet thickness discriminating apparatus of the present invention is applied. This apparatus is an image scanner that can be connected to a print output apparatus such as an LED printer that reads a large-size sheet up to A0 size, for example, and is also used in a copier in which the scanner section and the printer section are integrated.

  The image scanner includes a main body 10 that reads data written on a sheet P, a lid 30 that can be lifted up and down by a link mechanism 20 in the direction of arrow a corresponding to the thickness of the sheet P, and a sheet. It is comprised with a pair of conveyance roller 40 which conveys P. In addition, the data described on the sheet P refers to images, characters, or data including these.

  The main body 10 includes a reading unit 11, and a feed roller 12 and a discharge roller 13 disposed so as to sandwich the reading unit 11. The reading unit 11 is a reduction optical system, and is an image in which a first mirror M1, a second mirror M2, a third mirror M3, a fourth mirror M4, a projection lens L, and an imaging element are arranged in a line. The sensor S, two light sources (L 1, L 2), and a fixed base 11 are included.

  In order to allow the light of the light source reflected on the sheet P to reach the image sensor S, the first mirror M1, the second mirror M2, the third mirror M3, and the fourth mirror M4 have a predetermined angle on the fixed base 11. Are arranged. With such a configuration, the light of the light source (L1, L2) reflected on the sheet P is projected through the first mirror M1, the second mirror M2, and the third mirror M3, the fourth mirror M4, respectively. The light is condensed by the lens L and read by the image sensor S.

  The lid 30 includes a front pressing roller 31, a platen roller 32, and a rear pressing roller 33. The front pressing roller 31 is disposed on the sheet insertion side, and is attached to a position facing the feeding roller 12 when set to a position for reading the sheet P. Further, the rear presser roller 33 is disposed on the sheet discharge side, and is attached to a position facing the discharge roller 13 when set to a position for reading the sheet P. Further, the front presser roller 31 and the rear presser roller 33 are provided with two or more small rollers (not indicated) on the axis.

  Further, as shown in FIG. 2, the gap on the lid 30 side into which the sheet P is inserted becomes narrower toward the pair of transport rollers 40 so that the sheet P can be easily inserted into the pair of transport rollers 40. And a restricting portion 52 that restricts the conveyance of the sheet P having a thickness greater than or equal to a predetermined thickness. In addition, a sheet passage detection unit 70 that detects passage of the sheet P is disposed at a conveyance portion (no reference numeral) that faces the restriction portion 52.

  The platen roller 32 guides the sheet P sent from the front pressing roller 31 to the upper side of the contact glass, and fits the sheet P on the contact glass, that is, the reading position (reading surface). The feed roller 12 and the front pressing roller 31 constitute a pair of transport rollers 40.

  As with the front pressing roller 31 and the rear pressing roller 33, the feeding roller 12 and the discharge roller 13 are provided with two or more small rollers (not shown) on the axis, and further, the feeding roller 12 has a small roller (not shown). ) And a small roller (not indicated) of the front pressing roller 31, and a small roller of the discharge roller 13 and a small roller (not indicated) of the rear pressing roller 33 are arranged to face each other.

  Next, the thickness discrimination apparatus for the sheet P of the present invention will be described. As shown in FIG. 2, the sheet P thickness discriminating apparatus includes a guide 50 that guides the leading end of the sheet P between a pair of transport rollers 40, a sheet P guided from the guide 50, and a pair that transports the sheet P in a predetermined direction. And a detection means 60 for detecting the leading edge of the sheet P conveyed to the pair of conveyance rollers 40.

  In this embodiment, the pair of transport rollers 40 includes a feed roller 12 of the main body 10 and a front pressing roller 31 of the lid 30. The detection means 60 is provided at a position where the small roller of the feed roller 12 and the small roller of the front pressing roller 31 are not arranged to face each other. More specifically, the detection means 60 is provided on the upper side of the river where the sheet P is conveyed and in the vicinity of the position where the feed roller 12 and the front pressing roller 31 are in contact with each other, or on the upper side of the river where the sheet P is conveyed and the sheet. It is arranged in the vicinity of the position where the conveying rollers contact each other via P.

  Next, the operation will be described. When the leading edge of the sheet P is abutted between the small roller of the feeding roller 12 and the small roller of the front pressing roller 31, the sheet passing detection means 70 detects the leading edge of the sheet P as shown in FIG. When the detection means 60 detects the leading edge of the sheet P, it is determined that the thickness of the sheet P is thin. This determination is made by a control means (not shown).

  When the leading edge of the sheet P is abutted between the small roller of the feed roller 12 and the small roller of the front pressing roller 31, the sheet passage detecting means 70 detects the leading edge of the sheet P as shown in FIG. When the leading end of the sheet P is detected and the leading end of the sheet P is not detected, the leading end of the sheet P is in the following state. The leading edge of the sheet P deviates from the portion that bites into the original nip, and the leading edge of the sheet P is sandwiched between the small roller of the feed roller 12 and the small roller of the front pressing roller 31. From this, it is determined that the thick sheet P is being conveyed.

  Further, as shown in FIG. 3C, when the leading end of the sheet P is not detected by the sheet passing detection means 70 and the detection means 60, it is determined that the thickness of the sheet P read by the image reading apparatus exceeds.

  In this way, the thickness of the sheet P can be reduced only by the operation of abutting the leading end of the sheet P between the small roller of the feed roller 12 and the small roller of the front pressing roller 31 with a simple configuration. Can be determined.

1 is a schematic diagram of an image reading apparatus to which a sheet thickness determination apparatus of the present invention is applied. 1 is a schematic view of a sheet thickness discriminating apparatus according to the present invention. It is a figure which shows operation | movement of the sheet thickness discrimination | determination apparatus of this invention, (a) is a figure which shows the state which conveyed the thin sheet, (b) is a figure which shows the state which conveyed the thin sheet, (c) is a prescription | regulation. The figure which is going to convey the sheet | seat of the above thickness.

DESCRIPTION OF SYMBOLS 10 Main body part 20 Link mechanism 30 Lid 40 A pair of conveyance roller 50 Guide 60 Detection means 70 Sheet passage detection means P Sheet

Claims (3)

A guide for guiding the leading edge of the sheet between the conveying rollers, a pair of conveying rollers for conveying the sheet guided from the guide in a predetermined direction, and a leading edge of the sheet conveyed to the pair of conveying rollers are detected. Detecting means,
Two or more of each of the conveying rollers are disposed on the axis,
The detection means is located near the upstream side where the sheet is conveyed and the position where the conveyance rollers contact each other, or near the upstream side where the sheet is conveyed and the position where the conveyance rollers contact via the sheet. Placed in
The sheet thickness discriminating apparatus characterized in that the detecting means discriminates the thickness of the sheet based on a detection result of the leading edge of the sheet when abutting against the pair of conveying rollers.   2. The sheet thickness discriminating apparatus according to claim 1, wherein passage detection means for detecting passage of the sheet is disposed on a side of the detection means on which the sheet is conveyed.   The guide is gradually narrowed toward the conveyance roller, and includes an introduction unit that smoothly conveys the sheet to the conveyance roller side, and a regulation unit that regulates conveyance of the sheet having a predetermined thickness or more. 3. The sheet thickness discriminating apparatus according to claim 1, wherein the sheet thickness is discriminated.

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