JP2012151620A - Image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress leakage of magnetic noise from an imaging device more securely than in a conventional image reading device.SOLUTION: An image reading device 10 irradiates an original with light to scan it, and causes a lens device 3 to image the reflected light from the original in an imaging device 4 located therebehind. The imaging device 4 is covered with a shield case 9, which includes a front wall 931 having an opening 930; the lens device 3 includes a lens holding barrel 30 including a conductive ring 35 that is close to an aperture part Sq and includes a diaphragm aperture 351 for narrowing down light incident to be imaged in the imaging device 4 in a range permitting the light to pass; the front wall 93 is externally fitting-engaged to the opening 930 at a position next to the conductive ring 35 having the diaphragm aperture 351; and at least one of the front wall 93 of the shield casing 9 and a lens device-mounting member 5 is disposed conductively to the conductive ring 35.

Description

  The present invention relates to an image reading apparatus that scans an original while irradiating the original with light and forms reflected light including image information from the original on an imaging device behind the lens apparatus by a lens device.

A typical example of this type of image reading apparatus is shown in FIG. An image reading apparatus 10 ′ in FIG. 12 is obtained by mounting the following on an image reading apparatus frame F. That is,
An original placing glass plate G1 and an original panning glass plate G2,
A first scanning unit U1 disposed below the glass plates G1 and G2 to illuminate a document on the glass plate G1 or G2 and reflect reflected light from the document in the document sub-scanning direction X;
A second scanning unit U2 that reflects the reflected light from the first scanning unit U1 back to the opposite side in the sub-scanning direction X;
The lens device 3A and the imaging device 4 behind the lens device 3A.
The lens device 3A is an optical system that focuses the reflected light from the second unit U2 on the imaging device 4.

  An automatic document feeder (not shown) that also serves as an opening / closing cover is connected to a frame F by a hinge (not shown) that can be opened and closed.

The first scanning unit U1 includes an illuminating lamp 11 that irradiates a document on the glass plate G1 or G2 and a mirror 12 that reflects reflected light from the document in the document sub-scanning direction X.
The second scanning unit U2 includes mirrors 21 and 22 that reflect the reflected light from the first scanning unit U1 back to the opposite side in the sub-scanning direction X.

  According to this type of image reading apparatus, the document placement glass plate G1 is moved while the first and second scanning units U1 and U2 are moved in the document sub-scanning direction X from the document reading start position by a scanning unit driving mechanism (not shown). The original placed thereon can be optically scanned and reflected light including image information reflected from the original can be imaged on the imaging device 4 by the lens device 3A. At this time, the second scanning unit U2 moves at half the speed of the first scanning unit U1, and the distance from the document to the imaging position of the imaging device 4 is kept constant.

  Alternatively, the original can be conveyed along the glass plate G2 by the automatic document conveying device, and the scanning units U1 and U2 can be arranged at a fixed position for document panning to read the original.

In any case, the image information read by the imaging device 4 is subjected to necessary processing by an image processing unit (not shown) or the like, and is output from the image processing unit.
Such an image reading apparatus 10 ′ is used as a part of a copying machine, a part of a multifunction machine having both functions of a copying machine and a facsimile machine, and is connected to a personal computer or via a computer. Connected to a printer.

  The image information output from the image processing unit is used for forming a copy image of a document, transmitting document image information to a partner facsimile machine, displaying an image on a computer display, and printing an image by a printer.

  In any case, the image pickup apparatus employs a photoelectric conversion element such as a charge coupled device (CCD), and such a photoelectric conversion element emits electromagnetic wave noise when reading an image. The electromagnetic wave noise may cause malfunction of the device itself using the imaging apparatus, or may adversely affect office devices such as peripheral printers, medical devices, and the like, and may cause malfunctions in some cases.

  For this reason, such an imaging apparatus is generally covered with a shield housing for suppressing electromagnetic noise emission.

  However, today, in order to improve the reading speed, the reading clock in the imaging device is increasing more and more. For this reason, it has become impossible to sufficiently prevent electromagnetic wave noise leakage simply by covering the imaging device with a shield housing.

  In order to cope with this problem, the interval between the set screws of the shield housing is reduced, or a part called a ferrite core for preventing electromagnetic wave leakage or an expensive part such as a gasket is employed.

  However, even if the interval between the setscrews of the shield housing is reduced or the above expensive parts for preventing electromagnetic wave leakage are used, the original is scanned while being irradiated with light, and the original In an image reading device that forms an image on the imaging device behind the lens device using reflected light including image information with the lens device, an opening for securing an optical path in the lens device is required, and electromagnetic waves leak from a large opening provided for this purpose. It is difficult to solve the problem.

  The shield housing that covers the image pickup device has a double structure with a light shielding cover from the lens device to the image pickup device, or a large housing that covers the light incident side end (front end) of the lens device. (For example, JP-A-8-32762) has also been proposed.

JP-A-8-32762

  However, even if a double structure as described above or a large shield housing is adopted, it is difficult to solve the problem of electromagnetic waves leaking from a large opening for securing an optical path in the lens apparatus, and the cost is increased.

  Therefore, the present invention can scan the original while irradiating the original with light, and can form reflected light including image information from the original on the imaging apparatus behind the lens apparatus with the lens apparatus. Provided is an image reading apparatus covered with a shield housing for suppressing electromagnetic wave noise leakage, which can more reliably suppress electromagnetic wave noise leakage as compared with a conventional image reading apparatus of the same type. This is the first problem.

  Further, the present invention can scan the original while irradiating the original with light, and form reflected light including image information from the original on the imaging apparatus behind the lens apparatus by the lens apparatus. An image forming apparatus including an image reading device covered with a shield casing for suppressing electromagnetic wave noise leakage, and comparing electromagnetic wave noise leakage from an imaging device of the image reading device with a conventional similar image reading device. It is a second object to provide an image forming apparatus that can be more reliably suppressed and can form an image satisfactorily with less influence of electromagnetic noise.

In order to solve the first problem, the present invention provides:
The document can be scanned while irradiating the document with light, and reflected light including image information from the document can be imaged on the imaging device behind the lens device by the lens device, and the imaging device can suppress electromagnetic noise leakage. An image reading device covered with a shield housing for
The shield housing includes a front wall that takes a front position from the imaging device in the optical axis direction of the lens device, and the front wall includes an opening,
The lens holding lens barrel of the lens device has a diaphragm aperture that faces the diaphragm portion of the lens device and has a diaphragm aperture that is narrowed in a range that allows light to enter the lens device and form an image on the imaging device. Including the sex part,
The front wall is externally engaged with the opening at a portion facing the conductive portion of the lens holding barrel,
The lens device is attached to a lens device attachment member,
At least one of the front wall of the shield housing and the lens device mounting member is placed in a conductive state with a conductive portion having the aperture opening.

According to the image reading device of the present invention, the lens holding barrel of the lens device faces the lens aperture position of the lens device and allows light to enter the lens device and form an image on the imaging device. It includes a conductive portion having a diaphragm aperture that is narrowed to the extent permitted.
In other words, the conductive member faces the stop portion where the optical path of the lens device is constricted, that is, the portion having the smallest optical path cross-sectional area in the effective optical path, and enters the lens device and forms an image on the imaging device. It has an aperture stop that is narrowed in a range that allows light to pass through.

  The shield housing for suppressing electromagnetic wave noise leakage covering the imaging device is externally engaged with the lens holding lens barrel portion of the front wall facing the conductive portion having the aperture opening, At least one of the front wall of the shield housing and the lens device mounting member is in conduction with the conductive portion having the aperture opening.

  Accordingly, leakage of electromagnetic wave noise from the image sensor can be suppressed not only by the shield housing but also by the shield housing and the conductive portion having the aperture opening, and securing the optical path in the lens apparatus, which has been a problem in the past. Electromagnetic noise leakage from the large opening can be eliminated accordingly.

  Thus, a conventional image reading apparatus of the same type, that is, scanning the original while irradiating the original with light and forming reflected light including image information from the original on the imaging apparatus behind the lens apparatus by the lens apparatus. The image pickup device can more reliably suppress electromagnetic wave noise leakage than an image reading device covered with a shield housing for suppressing electromagnetic wave noise leakage.

  At least one of the shield housing and the lens device mounting member may be placed in a conductive state in the image reading device frame in order to more reliably suppress electromagnetic noise emission.

Examples of the image reading apparatus according to the present invention include the following image reading apparatuses (1) to (6).
<Image Reading Device (1)>
The lens holding lens barrel has a main body formed of a non-conductive material (for example, synthetic resin), and a conductive portion having the aperture opening is built in the lens holding lens barrel main body. At least one hole is formed in the main body wall, and at least one of the front wall of the shield housing and the lens device mounting member has a protrusion, and the protrusion has the lens holding lens barrel body. An image reading apparatus which is placed in a conductive state through a hole in a wall and has a conductive portion having the aperture opening.

In the image reading device (1),
(A) When the shield housing has a protrusion, and the protrusion passes through a hole in the lens holding barrel main body wall and is in conduction with the conductive portion,
(B) When the lens device mounting member has a protrusion, and the protrusion passes through a hole in the lens holding barrel main body wall and is in a conductive state with the conductive portion,
(C) Each of the shield housing and the lens device mounting member has a protrusion, and the protrusion penetrates through a hole corresponding to each protrusion of the lens holding barrel main body wall and the conductive portion. The case where it is in a conductive state can be illustrated.
In the case of (c), the shield housing is placed in a conductive state with the lens device mounting member via a conductive portion.

<Image Reading Device (2)>
The lens holding lens barrel has a main body formed of a non-conductive material (for example, synthetic resin), a conductive portion having the aperture opening is built in the lens holding lens barrel main body, and has the aperture opening. The conductive portion has at least one protrusion passing through at least one hole formed in the lens holding barrel body wall, and at least one of the front wall of the shield housing and the lens device mounting member. One is an image reading apparatus which is placed in a conductive state with the protrusion passing through the hole formed in the lens holding lens barrel body wall.

In the image reading device (2),
(A) When the shield housing is in a conductive state with the protrusion of the conductive portion,
(B) When the lens device mounting member is in a conductive state on the protrusion of the conductive portion,
(C) The case where each of the said shield housing | casing and the said lens apparatus attachment member is made into the conduction | electrical_connection state to the projection part of the said electroconductive part corresponding to them can be illustrated.
In the case of (c), the shield housing is placed in a conductive state with the lens device mounting member via a conductive portion.

<Image Reading Device (3)>
The lens holding barrel including the conductive portion having the aperture opening is formed of a conductive material, and at least one of the front wall of the shield housing and the lens device mounting member is attached to the lens holding barrel. An image reading device engaged so as to be conductive.

  In this image reading apparatus, when both of the front wall of the shield casing and the lens apparatus mounting member are engaged with the lens holding barrel in a conductive manner, the shield casing is the lens holding mirror. The lens apparatus mounting member is placed in a conductive state via the body, and thus through the conductive portion.

<Image Reading Device (4)>
In the image reading device (3), at least one hole is formed in a lens barrel wall of the lens holding lens barrel, and at least one of the front wall of the shield housing and the lens device mounting member is a protrusion. And at least one of the front wall of the shield housing and the lens device mounting member is attached to the lens holding lens barrel because the protrusion is inserted and engaged with the hole of the lens barrel wall. An image reading device engaged so as to be conductive.

<Image Reading Device (5)>
In the image reading device (3), at least one counterbore portion is formed on a lens barrel wall of the lens holding barrel, and at least one of the front wall of the shield housing and the lens device mounting member is An image reading device in which at least one of the front wall of the shield housing and the lens device mounting member is engaged with the lens holding barrel by being fitted and engaged with the counterbore portion.

  In the image reading devices (3) to (5), the lens holding barrel may be formed of, for example, a black anodized aluminum material in order to suppress optical noise from entering the imaging device.

  In any case, examples of the image pickup apparatus in the image reading apparatus according to the present invention include an apparatus in which the image pickup element employs a photoelectric conversion element such as a charge coupled device (CCD). However, another type of image sensor may be used.

In order to solve the second problem, the present invention provides an image forming apparatus including the image reading apparatus according to the present invention.
Since the image forming apparatus according to the present invention includes the image reading apparatus according to the present invention, electromagnetic wave noise leakage from the image pickup apparatus of the image reading apparatus can be more reliably suppressed as compared with a conventional image reading apparatus of the same type. Therefore, an image can be formed satisfactorily with less influence of electromagnetic noise.

  According to the present invention, the original can be scanned while irradiating the original with light, and reflected light including image information from the original can be imaged on the imaging device behind the lens device by the lens device. Provided is an image reading apparatus covered with a shield housing for suppressing electromagnetic wave noise leakage, which can more reliably suppress electromagnetic wave noise leakage as compared with a conventional image reading apparatus of the same type. be able to.

  According to the present invention, the original can be scanned while irradiating the original with light, and reflected light including image information from the original can be imaged by the lens device on the imaging device behind the lens device. Is an image forming apparatus provided with an image reading device covered with a shield housing for suppressing electromagnetic wave noise leakage, and electromagnetic wave noise leakage from the imaging device of the image reading device is similar to a conventional image reading device of the same type As compared with the above, it is possible to provide an image forming apparatus that can suppress more reliably and can form an image favorably with less influence of electromagnetic noise.

1 is a diagram illustrating an example of an image forming apparatus including an example of an image reading apparatus according to the present invention. It is a figure which shows the outline of the internal structure of the image reading apparatus shown in FIG. FIG. 3 is a perspective view of a lens device, a shield housing, and the like in the image reading apparatus of FIG. 2. 4A is an exploded perspective view of the lens device and shield housing of FIG. 3, and FIG. 4B is a perspective view of a lens device mounting plate. FIG. 4 is an exploded perspective view of the lens device shown in FIGS. 2 and 3. FIG. 4 is a cross-sectional view of the lens device, the imaging device, the lens device mounting plate, and the like shown in FIGS. 2 and 3. FIG. 7 is a horizontal cross-sectional view along the optical axis of the lens device and the imaging device of FIG. 6. It is a figure which shows the other example of an electroconductive part. FIG. 9 is a cross-sectional view of a lens device, an imaging device, a lens device mounting plate, and the like that employ the conductive portion of FIG. 8. It is a perspective view of the further another example of a lens apparatus. It is sectional drawing of the lens apparatus of FIG. 10, an imaging device, a lens apparatus attachment plate, etc. It is a figure which shows the prior art example of an image reading apparatus.

FIG. 1 shows an example 100 of an image forming apparatus provided with an example 10 of an image reading apparatus according to the present invention.
An image forming apparatus 100 in FIG. 1 is an image forming apparatus in which an image reading apparatus 10 is mounted on a printer unit 20.

  The printer unit 20 can form a copy image of a document based on the image information of the document read by the image reading device 10, and can also form an image based on image information supplied from a computer, a facsimile machine, etc. (not shown). You can also

The printer unit 20 can form an image on a recording sheet Sh such as a recording sheet by an electrophotographic method.
The printer unit may form a monochrome image or may form a color image, but the present example can form a color image.

  The printer unit 20 is a so-called tandem color printer in which a yellow image forming unit Y, a magenta image forming unit M, a cyan image forming unit C, and a black image forming unit K are arranged along the intermediate transfer belt b. The toner image formed by each image forming unit is primarily transferred to the intermediate transfer belt b, and the toner image that is primarily transferred over the belt b is supplied from one of the cassettes C1 to C4 of the sheet supply unit CS. The recording sheet Sh can be secondarily transferred, fixed by the fixing device f, and discharged onto the discharge tray T.

The image reading apparatus 10 is equipped with an automatic document feeder ADF, and has substantially the same structure as the image reading apparatus 10 ′ shown in FIG. 12 except for the points described below (shield housing and the like).
In the image reading apparatus 10, the same reference numerals as those of the image reading apparatus 10 ′ are assigned to the same parts and portions as the parts and parts of the image reading apparatus 10 ′.

  Similar to the image reading device 10 ′, the image reading device 10 is arranged on the glass plate G1 or G2 by being placed below the glass plate G1 for document placement and the glass plate G2 for document panning and the glass plates G1 and G2. The first scanning unit U1 that reflects the reflected light from the document in the document sub-scanning direction X, and the second scanning unit that reflects the reflected light from the first scanning unit U1 back to the opposite side in the sub-scanning direction X U2, the lens device 3 and the imaging device 4 behind the lens device 3 are included.

The image reading device 10 can read a document placed on the document placement glass plate G1 in the same manner as the image reading device 10 ′, and is placed on the document placement tray T1 by the automatic document feeder ADF. The placed document S is transported to the discharge tray T2 along the glass plate G2 by a document transport mechanism (not shown), and the scanning units U1 and U2 are arranged at fixed positions for document panning to read the document. You can also.
Image information read by the image reading apparatus 10 is supplied to the printer unit 20 or to an external computer, facsimile machine, or the like.

In the image reading device 10, the imaging device 4 employs a CCD (charge coupled device) as an imaging device, and a CCD substrate 41 on which the CCD is mounted is disposed behind the lens device 3.
As shown in FIGS. 5 and 6, the lens device 3 includes a synthetic resin lens holding barrel (lens barrel body) 30 and a conductive ring 35 and a two-lens 321 from the front side in the optical axis Lc (see FIG. 6) direction. The second group lens 32 consisting of 322 and the first group lens 31 consisting of one lens are press-fitted in this order, and the third group lens 33 consisting of two lenses 331 and 332 and the fourth group lens 34 consisting of one lens from the rear side. Are press-fitted in this order.

  The lens device 3 employs a double Gauss type lens composed of 6 lenses in 4 groups in which a diaphragm portion Sq is provided between the 2 group lens 32 and the 3 group lens 33. The optical path is narrowed in the vicinity of the stop.

The conductive ring 35 is disposed so as to face the throttle portion Sq.
The conductive ring 35 has a small aperture 351 that is narrowed in a range that allows light to be incident on the lens device 3 from the scanning unit U2 and imaged on the imaging device 4 to pass therethrough.

  As shown in FIG. 5 and FIG. 6, one slit-shaped hole 301 is formed on the upper surface side and one slit-shaped hole is also formed on the lower surface side of the wall of the lens holding lens barrel 30 of the lens device 3. 302 is formed.

  The lens device 3 is attached to the conductive lens device mounting plate 5 with its lens holding barrel 30. As shown in FIG. 4B, the lens device mounting plate 5 has an opening 51 into which the lower portion 30a of the front end portion of the lens holding barrel 30 is fitted and an opening 52 into which the lower portion 30b of the rear end portion of the lens holding barrel 30 is fitted. Have.

  The lens holding lens barrel 30 is fitted into the openings 51 and 52 of the lens device mounting plate 5 at the lower portions 30a and 30b, and is further provided with a protrusion standing on a portion 53 between the openings 51 and 52 of the mounting plate 5. 531 (see FIG. 6) is inserted into the lens barrel from the hole 302 on the lower surface side of the lens holding lens barrel, and is in contact with the conductive ring 35 so as to be electrically conductive.

  As shown in FIGS. 3 and 4A and the like, the lens device mounting plate 5 is attached to the conductive adjustment plate 6 so that the position thereof can be adjusted in the optical axis Lc direction. The conductivity adjusting plate 6 is attached to a conductive reinforcing plate 7 (see FIG. 2) so that the front / rear and left / right inclinations of the lens device 3 can be adjusted. The reinforcing plate 7 is electrically conductive to the image reading device frame F. Is attached to the bottom plate fb.

  As shown in FIG. 6, a substrate support member 8 for supporting the CCD substrate 41 of the imaging device 4 is attached to the rear end portion of the lens device attachment plate 5, and the CCD substrate 41 is supported by the substrate support member 8. Has been.

Further, a light shielding cover 300 for preventing light noise intrusion is provided from the rear end of the lens device 3 to the CCD substrate 41.
Furthermore, a shield housing 9 for suppressing electromagnetic wave noise leakage from the imaging device 4 is provided.

  As shown in FIGS. 3 and 4, the shield housing 9 includes a top wall 91, both side walls 92 descending from the top wall periphery, a front wall 93 and a rear wall 94. Yes. The shield housing 9 covers from the upper part of the light shielding cover 300 from almost the middle of the lens device 3 to the rear side of the imaging device 4, and is screwed to the lens device mounting plate 5, the reinforcing plate 7, and the like.

  As shown in FIGS. 4A and 6, an arch-shaped opening 930 is formed in the front wall 93 of the shield housing 9, and a protruding portion 931 protrudes integrally from the opening edge. The protrusion 931 is inserted into the lens barrel through the hole 301 on the upper surface side of the lens holding lens barrel 30 and is in contact with the conductive ring 35 so as to be electrically conductive.

  Thus, the shield housing 9 is electrically connected to the image reading device frame F via the reinforcing plate 7 and the like at the rear, and the lens device mounting plate 5 via the conductive ring 35 in the lens holding barrel at the front. Furthermore, it is electrically connected to the image reading device frame F.

  According to the image reading device 10, the lens holding lens barrel 30 of the lens device 3 faces the diaphragm portion Sq of the lens device 3 and enters the lens device 3 to allow passage of light to be imaged on the imaging device 4. And a conductive ring 35 having a diaphragm opening 351 squeezed at.

  More specifically, the conductive ring 35 faces the portion where the optical path of the lens device 3 is constricted, and is narrowed in a range that allows the light that is incident on the lens device 3 and imaged on the imaging device 4 to pass therethrough. And a small aperture 351.

The shield housing 9 for suppressing electromagnetic wave noise leakage is fitted and fitted through an opening 930 to a lens holding barrel portion whose front wall 93 faces the conductive ring 35 having the aperture opening 351. The front wall 93 of the body 9 and the lens device mounting plate 5 are in conduction with the conductive ring 35.

  Therefore, electromagnetic wave noise leakage from the CCD substrate 41 is suppressed not only by the shield housing 9 but also by the shield housing 9 and the conductive ring 35 having the narrowed aperture opening 351 (with a small opening area). Therefore, the problem of electromagnetic wave noise leakage from a large aperture for securing an optical path in the lens apparatus, which has been regarded as a problem in the past, can be solved accordingly.

FIG. 7 is a horizontal sectional view along the optical axis Lc of the lens apparatus and the imaging apparatus of FIG. 6, and as can be seen from this figure, the opening through which the light of the shield housing passes is more optically focused than the lens apparatus 3. If it is provided at the front position A or the position B facing the CCD substrate on the rear side of the lens device 3 in the direction, the opening must be enlarged, but the shield housing 9 is provided at the position C facing the diaphragm Sq. Therefore, it can be seen that it can be formed smaller than the positions A and B.
Thus, electromagnetic noise leakage can be more reliably suppressed as compared with a conventional image reading apparatus of the same type.

  In the lens device 3 of FIG. 6, the conductive ring 35 in the lens holding lens barrel 30 is a circular ring having no protrusions at the peripheral edge, but instead of this ring 35, as shown in FIG. Alternatively, a ring 35 ′ may be employed in which a protrusion is protruded from the peripheral edge. The ring 35 ′ is the same as the ring 35 except for the protrusions 352 and 353. An opening 351 having the same dimensions as the ring 35 is also provided.

  When this ring 35 ′ is employed, as shown in FIG. 9, the protrusion 352 of the ring 35 ′ protrudes from the hole 303 formed on the upper surface side of the lens holding barrel 30, and the protrusion 352 has the shield housing 9. The protrusion 931 at the opening edge of the front wall 93 is brought into contact so as to be conductive, and the protrusion 353 of the ring 35 ′ is protruded from the hole 304 formed on the lower surface side of the lens holding barrel 30 and the lens device mounting plate 5. May be brought into contact with each other so as to be conductive.

  Even with this configuration, electromagnetic wave noise leakage can be more reliably suppressed as compared with the conventional image reading apparatus of the same type as in the case of FIG.

  The lens holding barrel in the lens apparatus may be formed of a conductive material. FIG. 10 shows a lens apparatus 3 ′ in which the lens holding barrel 30 ′ is formed of an aluminum material that has been black anodized. This lens device 3 ′ may be employed instead of the lens device 3.

  The lens holding lens barrel 30 'is integrally formed as a whole, and has a counterbore 30c on the upper surface side and a counterbore 30d on the lower surface side. As shown in FIG. 11, the same lens groups 31, 32, 33, and 34 as in the lens apparatus 3 are fitted and arranged inside the lens barrel.

  The lens holding lens barrel 30 ′ has a configuration in which the conductive ring 35 in the case of the lens apparatus 3 is also integrally formed, and the portion 35 ′ corresponding to the conductive ring 35 is disposed so as to face the diaphragm portion Sq. It has a small aperture 351 ′ that is narrowed in a range that allows light that is incident on the lens device 3 ′ from the scanning unit U2 to be imaged on the imaging device 4 to pass therethrough.

  The lens barrel 30 ′ is fitted into the openings 51 ′ and 52 ′ of the lens device mounting plate 5 as in the case of the lens device 3, and further, a portion 53 ′ between the openings 51 ′ and 52 ′ of the mounting plate 5 is formed. What is necessary is just to insert and engage with the lower counterbore part 30d of the lens barrel 30 'to set a conductive state between them.

Further, the edge of the opening 930 of the front wall 93 of the shield housing 9 (in this case, the opening edge with no protrusion) is fitted into and engaged with the upper counterbore 30c of the lens barrel 30 ′, and the gap between the two. What is necessary is just to set a conduction | electrical_connection state.
Even with this configuration, electromagnetic wave noise leakage can be more reliably suppressed as compared with the conventional image reading apparatus of the same type as in the case of FIG.

  In the lens device 3 ′, the shield housing 9 and the lens device are attached to the spot facing portions 30c and 30d in which the conduction setting between the shield housing 9 and the lens device mounting plate 5 and the lens holding lens barrel 30 ′ is formed in the lens barrel 30 ′. This is performed by engaging the plate 5, but the projection (not shown) from the shield housing 9 and the lens device mounting plate 5 is engaged and conducted in a hole (not shown) formed in the lens holding lens barrel 30 ′. May be.

  An image reading apparatus that optically reads a document image, and can be used to provide an image reading apparatus that can more reliably suppress electromagnetic wave noise leakage from an imaging apparatus as compared with a conventional image reading apparatus of the same type. .

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 10 Image reading apparatus F Image reading apparatus frame 9 Shield housing 93 Front wall 930 Front wall opening part 931 Protrusion part 20 Printer part 3, 3 'Lens apparatus Sq Diaphragm part 30, 30' Lens holding barrel 31, 32, 33, 34, 35 Lens group 35, 35 ′ Conductive ring 351 Conductive ring opening 352, 353 Conductive ring protrusion 301, 302, 303, 304 Lens holding lens barrel hole 30c, 30d Lens Counterbore part 4 of holding lens barrel 30 'Imaging device 41 CCD substrate 5 Lens device mounting plate

Claims (8)

The document can be scanned while irradiating the document with light, and reflected light including image information from the document can be imaged on the imaging device behind the lens device by the lens device, and the imaging device can suppress electromagnetic noise leakage. An image reading device covered with a shield housing for
The shield housing includes a front wall that takes a front position from the imaging device in the optical axis direction of the lens device, and the front wall includes an opening,
The lens holding lens barrel of the lens device has a diaphragm aperture that faces the diaphragm portion of the lens device and has a diaphragm aperture that is narrowed in a range that allows light to enter the lens device and form an image on the imaging device. Including the sex part,
The front wall is externally engaged with the opening at a portion facing the conductive portion of the lens holding barrel,
The lens device is attached to a lens device attachment member,
An image reading apparatus, wherein at least one of the front wall of the shield housing and the lens device mounting member is in conduction with a conductive portion having the aperture opening.   The lens holding lens barrel has a main body formed of a non-conductive material, a conductive portion having the aperture opening is built in the lens holding lens barrel main body, and at least one of the lens holding lens barrel main walls is provided. And at least one of the front wall of the shield housing and the lens device mounting member has a protrusion, and the protrusion penetrates the hole of the lens holding lens barrel body wall. The image reading apparatus according to claim 1, wherein the image reading apparatus is placed in a conductive state with the conductive portion having the aperture opening.   The lens holding barrel has a main body formed of a non-conductive material, and a conductive portion having the aperture opening is built in the lens holding barrel main body, and the conductive portion having the aperture opening is The lens holding lens barrel body wall has at least one protrusion penetrating through at least one hole, and at least one of the front wall of the shield housing and the lens device mounting member is the lens holding member. The image reading apparatus according to claim 1, wherein the protrusion is formed in a conductive state through the hole formed in the lens barrel body wall.   The lens holding barrel including the conductive portion having the aperture opening is formed of a conductive material, and at least one of the front wall of the shield housing and the lens device mounting member is attached to the lens holding barrel. The image reading device according to claim 1, wherein the image reading device is engaged so as to be conductive.   At least one hole is formed in the lens barrel wall of the lens holding barrel, and at least one of the front wall of the shield housing and the lens device mounting member has a protrusion, and the protrusion Is inserted and engaged with a hole in the lens barrel wall, so that at least one of the front wall of the shield housing and the lens device mounting member is engaged with the lens holding lens barrel in a conductive manner. Item 5. The image reading apparatus according to Item 4.   At least one counterbore portion is formed on the lens barrel wall of the lens holding barrel, and at least one of the front wall of the shield housing and the lens device mounting member is fitted and engaged with the counterbore portion. 5. The image reading apparatus according to claim 4, wherein at least one of the front wall of the shield housing and the lens device mounting member is engaged with the lens holding barrel in a conductive manner.   7. The image reading apparatus according to claim 4, wherein the lens holding barrel is formed of an aluminum material that has been subjected to black alumite treatment. An image forming apparatus comprising the image reading apparatus according to claim 1.

Images