Patent Description:
Conventionally, in the image reading apparatus mounted in a copying machine or the like, one in which a reading unit is provided inside an automatic document (original) feeder (ADF) for feeding originals while separating the originals one by one has been known. In the case where the reading unit is provided inside the AFD, in order to clean a glass surface opposing the original and the eliminate (clear) an original jam, a conveying passage is constituted openably so that the glass surface of the reading unit is exposed to an outside of the image reading apparatus in some cases. In Japanese Laid-Open Patent Application <CIT>, a constitution in which in order to expose the glass surface of the reading unit to the outside of the image reading apparatus, a conveying guide member provided below the conveying passage of the ADF is rotated is disclosed.

<CIT> discloses a document reading apparatus having the features in the preamble of claim <NUM>. <CIT> discloses further prior art.

However, in the constitution disclosed in <CIT>, a use makes access the glass surface of the reading unit from below the ADF. In such a case, there is a need to clean the glass surface in a manner such that the user looks into the reading unit from below the ADF, and therefore, there was a problem that the glass surface is not readily cleaned.

A principal object of the present invention is to provide an image reading apparatus capable of facilitating cleaning of a glass surface of a reading unit and to provide an image forming apparatus including the image reading apparatus.

The above object is solved by an image reading apparatus according to claim <NUM>. Further advantageous embodiments are disclosed in the dependent claims.

In the following, embodiments according to the present invention will be described with reference to the drawings.

First, a schematic structure of an image forming apparatus <NUM> according to an embodiment will be described using <FIG>. The image forming apparatus <NUM> of this embodiment is a color electrophotographic apparatus including, as image forming means, an image forming mechanism 1B including four image forming portions PY, PM, PC and PK. The image forming apparatus <NUM> forms an image on a sheet S on the basis of image information received from an original reading apparatus <NUM> provided at an upper portion of an apparatus main assembly 1A or from an external device. As the sheet which is a recording material, it is possible to use a variety of sheet materials different in size and material, including papers such as plain paper and thick paper, a plastic film, a cloth, a surface-treated sheet material such as coated paper, special-shaped sheet materials such as an envelope and index paper, and the like.

The image forming apparatus <NUM> includes a main controller <NUM>. The main controller <NUM> includes a CPU as an executing means for executing a control program for the image forming apparatus <NUM>, an ROM for storing a program, an RAM for temporarily storing data, and an input/output circuit for inputting and outputting signals between itself and an outside. The CPU reads the program from the ROM and then executes the program, and provides instructions to respective portions of the image forming apparatus <NUM> through the input/output circuit, so that the CPU controls an operation of the image forming apparatus <NUM>. For example, the main controller <NUM> is electrically connected to a controller 2C of the original reading apparatus <NUM>. The main controller <NUM> receives the image information read from an original by reading units <NUM> and <NUM> through the controller 2C and then is capable of performing an image forming operation (copying) for forming, on the sheet S, an image based on the received image information.

The image forming portions PY, PM, PC and PK are units for forming toner images of yellow, magenta, cyan and black, respectively. The image forming portions PY to PK are also called process units or image forming stations. The four image forming portions PY to PK have the substantially same constitution except that colors of toners used for forming the toner images are different from each other. Each of the image forming portions PY to PK includes a photosensitive drum <NUM> which is a photosensitive member formed in a drum shape, and as process means actable on the photosensitive member and for executing an electrophotographic means, such as charging device <NUM>, a developing device <NUM>, and a drum cleaner <NUM>. Below each of the image forming portions PY to PK, an exposure device <NUM> as the process means (exposure means) for exposing the associated photosensitive drum <NUM> to light is provided. Above each of the image forming portions PY to PK, a supply container <NUM> for supplying a developer to an associated developing device <NUM> is mounted detachably mountable to the apparatus main assembly 1A.

Above the image forming portions PY to PK, an intermediary transfer unit <NUM> is provided. The intermediary transfer unit <NUM> includes an intermediary transfer belt <NUM> which is an intermediary transfer member constituted by an endless flexible member, and a plurality of rollers for stretching the intermediary transfer belt <NUM>. The plurality of rollers includes an inner secondary transfer roller <NUM>. On an outer periphery side, a secondary transfer roller <NUM> is provided at a position opposing the inner secondary transfer roller <NUM> while sandwiching the intermediary transfer belt <NUM> therebetween. As a nip between the secondary transfer roller <NUM> and the inner secondary transfer roller <NUM>, a transfer portion (secondary transfer portion T2) where an image is transferred from the intermediary transfer belt <NUM> onto the sheet S is formed. On an inner peripheral side of the intermediary transfer belt <NUM>, at a position opposing each photosensitive drum <NUM>, a primary transfer roller <NUM> is provided while sandwiching the intermediary transfer belt <NUM> therebetween. Further, on the outer peripheral side of the intermediary transfer belt <NUM>, a belt cleaner <NUM> is provided.

At a lower portion of the apparatus main assembly 1A, a sheet feeding portion for feeding sheets S is provided. The sheet feeding portion includes a cassette <NUM> provided detachably mountable to the apparatus main assembly 1A and a feeding unit for feeding the sheets S, stacked and accommodated in the cassette <NUM>, while separating the sheets S one by one. On a feeding passage from the sheet feeding portion to the secondary transfer portion T2, a feeding roller pair <NUM> and a registration roller pair <NUM> are provided.

On a side downstream of the secondary transfer portion T2 with respect to a sheet feeding direction, a fixing device <NUM> is provided. The fixing device <NUM> includes a fixing roller <NUM> as a heating member, a pressing roller <NUM> as a pressing member, and an unshown heating means for heating the fixing roller <NUM>. As the heating means, it is possible to use a halogen lamp and a heating unit of an electromagnetic induction type. On a side further downstream of the fixing device <NUM>, a discharging roller <NUM> as a discharging means for discharging the sheet S, on which the image is formed, to an outside of the apparatus main assembly 1A is provided. At an upper surface portion of the apparatus main assembly 1A, a discharge tray <NUM> as a stacking portion on which the sheets, on which the images are formed, are to be stacked is provided. This embodiment employs a constitution of a so-called in-body discharge type in which a space in which the sheets S, on which the images are formed, are to be discharged and stacked is formed between the apparatus main assembly 1A and the original reading apparatus <NUM> with respect to an up-down direction (vertical direction in the case where the image forming apparatus <NUM> is installed on a horizontal surface).

When the main controller <NUM> receives image information and an execution instruction of an image forming operation, the main controller <NUM>, execute the image forming operation in a following manner. First, in each of the image forming portions PY to PK, rotation of the photosensitive drum <NUM> is started, and then the surface of the photosensitive drum <NUM> is electrically charged uniformly to a predetermined polarity and a predetermined potential by the charging device <NUM>. The surface of the photosensitive drum <NUM> is irradiated with (exposed to) laser light modulated depending on an image signal (video signal) based on the image information, so that an electrostatic latent image corresponding to a component image of an associated color of yellow, magenta, cyan and black is written (formed) on the photosensitive drum <NUM>. The resultant electrostatic latent images are developed with develops containing toners of the respective colors, so that toner images of yellow, magenta, cyan and black are prepared on the photosensitive drums <NUM>. The toner images carried on the photosensitive drums <NUM> are primary-transferred from the photosensitive drums <NUM> onto the intermediary transfer belt <NUM> by the primary transfer rollers <NUM>. At this time, the toner images of the respective colors are superposed on each other on the intermediary transfer belt <NUM>, so that an image as a full-color image is formed on the intermediary transfer belt <NUM>. A deposited matter such as transfer residual toner remaining on the surface of the photosensitive drum <NUM> without being transferred onto the intermediary transfer belt <NUM> is removed by the drum cleaner <NUM>. The image formed on the intermediary transfer belt <NUM> is conveyed to the secondary transfer portion T2 by rotation of the intermediary transfer belt <NUM>.

In parallel to a toner image forming process in each of the image forming portions PY to PK, one sheet S is fed from the cassette <NUM> and is conveyed to the registration roller pair <NUM> through the feeding roller pair <NUM>. The registration roller pair <NUM> corrects oblique movement of the sheet S, and thereafter conveys the sheet S to the secondary transfer portion T2 so that arrival of the image, carried on the intermediary transfer belt <NUM>, at the secondary transfer portion T2 and arrival of the sheet S at the secondary transfer portion T2 are synchronized with each other. In the secondary transfer portion T2, the image is transferred (secondary-transferred) from the intermediary transfer belt <NUM> onto the sheet S under application of a bias voltage to the secondary transfer roller <NUM>. A deposited matter such as the toner remaining on the intermediary transfer belt <NUM> without being transferred on the sheet S is removed by a belt cleaner <NUM>.

The sheet S passed through the secondary transfer portion T2 is conveyed to the fixing device <NUM>. The fixing device <NUM> heats and presses the image on the sheet S while nipping and feeding the sheet S in a nip (fixing nip) between the fixing roller <NUM> and the pressing roller <NUM>. By this, the toner is melted and color-mixed and then is fixed, so that the image fixed on the sheet S is obtained. The sheet S passed through the fixing device <NUM> is discharged by discharging roller <NUM>, so that the sheet S is stacked on a discharge tray <NUM>. By this, a series of image forming operations is ended.

Incidentally, in this embodiment, the color electrophotographic apparatus of the intermediary transfer type was described as an example, but the image forming apparatus <NUM> may include an image forming means of a direct transfer type in which a toner image formed on an image bearing member is transferred onto the sheet S without through the intermediary transfer member. Further, an image forming type is not limited to the electrophotographic type, and the image forming apparatus <NUM> may also include, as the image forming means, a printing unit of an ink jet type or an offset printing mechanism.

The original reading apparatus <NUM> which is an example of the image reading apparatus will be described using <FIG>. The original reading apparatus <NUM> includes a scanner portion (main body portion, lower portion unit) <NUM> and an ADF <NUM> provided on an upper portion of the scanner portion <NUM> and used as an upper unit supported rotatably by the scanner portion <NUM>. The original reading apparatus <NUM> is capable of executing an operation for reading image information from a static original placed on an original supporting platen glass of the scanner portion <NUM> (fixed reading operation) and an operation for reading the image information while feeding a sheet as an original by the ADF <NUM> (moving (skimming-through) reading operation).

The scanner portion <NUM> includes the original supporting platen glass on which the original is to be placed and a reading unit <NUM> for reading the image information of the original placed on the original supporting platen glass while moving below the original supporting platen glass in a sub-scan direction (left-right direction) in <FIG>. Further, the scanner portion <NUM> includes a glass <NUM> as a transparent member. The reading unit <NUM> is capable of reading the image information by optically scanning the original, fed by the ADF <NUM>, through the glass <NUM>.

The reading unit <NUM> includes a sensor substrate <NUM> on which a CCD image sensor as a light receiving element is mounted, an illumination portion <NUM> for illuminating the original with light, and a reduction optical system including a plurality of mirrors <NUM> and for imaging reflected light from the original onto an imaging surface of the light receiving element. In this embodiment, the reading unit <NUM> of a CCD type is shown, but a reading unit <NUM> of a CIS type in which the reflected light from the original is imaged on an imaging surface of a CMOS sensor, provided opposed to the original, through a <NUM>:<NUM> magnification optical system. The image information read by the reading unit <NUM> is transmitted to a controller 2C through a signal line <NUM>.

The ADF <NUM> includes an original tray <NUM>, a discharge tray <NUM>, an ADF main body 10A in which an original conveying passage P1 is formed, and a reading unit <NUM> provided along the original conveying passage P1. In the ADF main body 10A, as a sheet feeding (conveying) member for feeding (conveying) the sheet, a feeding roller <NUM>, a separation roller pair <NUM>, conveying roller pairs <NUM>, <NUM> and <NUM>, and a discharging roller pair <NUM> are provided along the original conveying passage P1. The original tray <NUM> is a stacking portion on which sheets are to be stacked, and the discharge tray <NUM> is a discharge portion where the sheet from which the image information is read is discharged. The original tray <NUM> is positioned above the discharge tray <NUM>, and as viewed from a point of view of <FIG> (in a state viewed in a sheet widthwise direction), the original conveying passage P1 is curved in a U-shaped which open toward one side of the horizontal direction.

The reading unit <NUM> includes a contact image sensor (CIS) <NUM> as a reading portion, a reading frame <NUM> for holding the CIS <NUM>, and a glass <NUM> (see also <FIG>). The glass <NUM> is a transparent member opposing the original conveying passage (sheet conveying passage) P1, and the CIS <NUM> functions as a reading portion for reading the image information from the original (sheet), conveyed along the original conveying passage P1, through the transparent member.

The reading frame <NUM> and the glass <NUM> form a substantially rectangular parallelopiped-shaped space for accommodating the CIS <NUM>. The CIS <NUM> includes a sensor substrate 112c on which a CMOS image sensor as a light receiving element is mounted, an illumination portion for illuminating the original with light, and a lens 112b for constituting a <NUM>:<NUM> optical system for imaging the reflected light, from the original, on an imaging surface of the light receiving element (see also <FIG>). In this embodiment, the reading unit <NUM> of a CIS type is shown, but an image sensor unit of a CCD type may be used as the reading unit <NUM>. The image information read by the reading unit is transmitted to the controller 2C through an electric wire <NUM>. A wiring path of the electric wire <NUM> will be specifically described.

An original feeding (conveying) operation by the ADF <NUM> will be described using <FIG>. When a user sets an original bundle on the original tray <NUM> and provides a start instruction of a reading operation through an unshown operating portion, the sheets are fed from the original tray <NUM> by the feeding roller <NUM> in an order from an uppermost original. The fed sheet is conveyed in a state in which the sheets are separated one by one by the separation roller pair <NUM> and then conveyed along the original conveying passage P1 while successively delivered by the conveying roller pairs <NUM>, <NUM> and <NUM>.

Then, when the original passes through the glass <NUM> of the scanner portion <NUM>, image information of a first side of the original is read by the reading unit <NUM>. Similarly, when the original passes through the glass <NUM>, image information of a second side opposite from the first side of the original is read by the CIS <NUM> of the reading unit <NUM>. The original from which the pieces of image information are read is discharged to an outside of the ADF main body 10A by the discharging roller pair <NUM> and then is stacked on the discharge tray <NUM>.

In the following description and drawing, the vertical direction in a state in which the image forming apparatus <NUM> is installed on the horizontal surface is referred to as a "Z-direction". A sheet widthwise direction perpendicular to the original feeding direction of the original fed along the original conveying passage P1 is referred to as an "X-direction". The X-direction is a main scan direction during image reading and may preferably be a direction (horizontal direction) perpendicular to the Z-direction. The horizontal direction as viewed in the X-direction is referred to as a "Y-direction". The X-direction, the Y-direction, and the Z-direction are directions crossing each other and may preferably be directions perpendicular to each other.

Incidentally, as shown in <FIG>, the ADF <NUM> includes an upper portion cover <NUM> as a cover unit constituting an upper surface portion of the ADF main body 10A. The upper portion cover <NUM> is rotatably supported by a frame of the ADF main body 10A through a supporting portion 147a, and is rotatable about an axis (first rotational axis) extending in the X-direction. The upper portion cover <NUM> is provided with a conveying guide <NUM> as an opposing guide (upper-side guiding surface) forming the original conveying passage P1 between itself and a guiding surface (lower-side guiding surface) of a rotation guide <NUM> supported by the ADF main body 10A. As shown in <FIG>, in a state in which the upper portion cover <NUM> is closed, a state in which a part of the rotation guide <NUM> is covered with the upper portion cover <NUM> is formed. Here, in the state in which the upper portion cover <NUM> is closed, entirety of the rotation guide <NUM> may also be covered with the upper portion cover <NUM>. Further, the upper portion cover <NUM> is provided with the feeding roller <NUM>, one (upper-side roller in the figure) of the separation roller pair <NUM>, and one (upper-side roller in the figure) of the conveying roller pair <NUM>. Accordingly, when the upper portion cover <NUM> is rotated from a closed position shown in <FIG> to an open position shown in <FIG>, a part of the original conveying passage P1 is opened, so that the rotation guide <NUM> is exposed to an outside of the ADF <NUM>, and thus a state in which the rotation guide <NUM> is capable of being rotated as described later.

Incidentally, during repetition of the moving reading operation of the original reading apparatus <NUM>, foreign matters including dust such as paper powder, and contaminants such as paste (adhesive) and ink which have been deposited on the original are deposited on the glasses <NUM> and <NUM> in some cases. When the moving reading operation is performed in a state in which the foreign matters are deposited on the glasses <NUM> and <NUM> within reading ranges of the reading units <NUM> and <NUM>, stripe images which do not originally exist on the original are read at positions corresponding to the foreign matters. This phenomenon is caused by a shadow created by blocking an optical path, during reading by the reading units <NUM> and <NUM>, with the foreign matters deposited on the glasses <NUM> and <NUM> (hereinafter, this phenomenon is referred to as an "image stripe(s)").

In order to eliminate an occurrence of the image stripe, removal of the foreign matters, causing the occurrence of the image stripe, through appropriate cleaning of the glasses <NUM> and <NUM> is effective. As regards the reading unit <NUM> of the scanner portion <NUM>, the glass <NUM> of the reading unit <NUM> is exposed by rotating the ADF <NUM> upward, and therefore, the glass <NUM> can be cleaned from above. On the other hand, the reading unit <NUM> of the ADF <NUM> is disposed inside the ADF main body 10A. As shown in <FIG>, in this embodiment, the reading unit <NUM> is disposed in an inside region of the original conveying passage P1 formed below the rotation guide <NUM> and curved in a U-shape. For that reason, a constitution for exposing the glass <NUM> to the outside (means for enabling access to the glass <NUM>) is needed.

Here, as a method of exposing the glass <NUM> of the reading unit <NUM> to the outside, a constitution in which the reading unit <NUM> is supported by the rotation guide <NUM> and is rotated integrally with the rotation guide <NUM> would be considered. However, in such a constitution, the reading unit <NUM> is rotated integrally with the rotation guide <NUM>, and therefore, when the rotation guide abuts against another member, impact depending on an entire weight of a rotatable unit including the reading unit <NUM> and the rotation guide <NUM> generates. The reading unit <NUM> is a precise device in which an electronic circuit including a light receiving element, and optical elements constituting an illumination portion and a <NUM>:<NUM> optical system or a reduction optical system are provided. For that reason, in the case where the rotation guide <NUM> is rotated for exposing the glass <NUM> to the outside, when large impact is exerted on the reading unit <NUM>, there is a possibility that inside component parts are broken or displaced.

Therefore, as described in the following, in this embodiment, a constitution in which not only the rotation guide <NUM> as a rotatable conveying guide is provided but also the reading unit <NUM> is made rotatable, independently of the rotation guide <NUM>, about a rotational axis different from the rotational axis of the rotation guide <NUM> is employed. By rotating the rotation guide <NUM> and the reading unit <NUM>, the glass <NUM> which is a surface opposing a sheet (object to be read) of the reading unit <NUM> is exposed to the outside. By this, the impact exerted on the reading unit <NUM> when the reading unit <NUM> is moved for performing the cleaning of the glass <NUM> or jam clearance can be reduced. Further, by employing a constitution in which the reading unit <NUM> is made rotatable independently of the rotation guide <NUM>, stress exerted on the electric wire connecting the reading unit <NUM> and the controller 2C to each other can also be reduced.

In the following, specific constitutions of the reading unit <NUM> and a periphery thereof will be described while citing embodiments.

First, an embodiment <NUM> will be described using <FIG>. <FIG> is a side view showing a part of components of the ADF <NUM>. In this embodiment, in the case where the ADF <NUM> is viewed in the X-direction from a front surface side of the image forming apparatus <NUM>, members positioned inside the original conveying passage P1, and a base conveying guide <NUM> and an arm <NUM> are shown in <FIG>. <FIG> is a sectional view of the reading unit <NUM> cut along a plane perpendicular to the X-direction.

As shown in <FIG> and <FIG>, to a bottom (opening of the reading frame <NUM> having a substantially U-shape in cross section) of the reading unit <NUM> in which the CIS <NUM> is incorporated, the glass <NUM> is stuck. Further, to each of opposite end portions of the glass <NUM> with respect to the X-direction (longitudinal direction of the CIS <NUM>, main scan direction), a gap sheet <NUM> is stuck.

<FIG> shows a state of an IV-IV cross section of <FIG>. Incidentally, the IV-IV cross section is a cross section obtained by cutting the reading unit <NUM> along a plane (plane extending in the X-direction and a sheet thickness direction D2 at a scanning position) perpendicular to a sheet feeding direction D1 at the scanning position of the reading unit <NUM>. As shown in <FIG> and <FIG>, each of the two gap sheets <NUM> stuck to (mounted on) the opposite end portions of the glass <NUM> with respect to the X-direction abuts against a shading plate <NUM> which is an opposing member opposing the glass <NUM>. As a result, in a region (original passing region) between the gap sheets <NUM> with respect to the X-direction, as shown in <FIG>, a gap corresponding to a thickness of the gap sheets <NUM> is ensured between the glass <NUM> and the shading plate <NUM>. That is, the gap sheets <NUM> function as a gap forming member for forming a gap between the glass <NUM> and the opposing member in contact with the opposing member opposing the glass <NUM>. The gap forming member is not limited to the gap sheets <NUM> when the member ensures (defines) a width (range) of the gap, and for example, a projection projecting toward the glass <NUM> may be formed integrally with the reading frame <NUM>.

Incidentally, the shading plate <NUM> is mounted on the base conveying guide <NUM> which is a conveying guide opposing the reading unit <NUM>, and the base conveying guide <NUM> is mounted on the frame of the ADF <NUM>. That is, the shading plate <NUM> and the base conveying guide <NUM> are members fixed to the frame of the ADF <NUM>.

Further, a pressing portion <NUM> for pressing the reading unit <NUM> is provided so stat the reading unit <NUM> is stably at rest at abutment positions of the glass sheets <NUM> (<FIG>).

The pressing portion <NUM> is provided at an upper portion (on a side opposite from the glass <NUM>) of the reading unit <NUM>. The pressing portion <NUM> includes a resin cover 114a as a contacted portion contacted to a pressing surface 141a (<FIG>) provided on the bottom of the rotation guide <NUM>, and a compression spring 114b as an elastic member interposed between the resin cover 114a and the reading frame <NUM>.

The rotation guide <NUM> includes a shaft portion 141c rotatably supported by the frame of the ADF <NUM> and is rotatable about a rotational axis A1 (second rotational axis). In this embodiment, the rotational axis A1 is provided at an upstream end (one-side end portion with respect to the Y-direction) of the rotation guide <NUM> with respect to the sheet feeding direction of the sheet fed from the feeding roller <NUM> toward the separation roller pair <NUM>, but may also be provided at another position. Further, a supporting portion is not limited to the shaft portion 141c when the supporting portion is a supporting portion for rotatably supporting the rotation guide <NUM>, and the rotation guide <NUM> may be provided with a hole (bearing portion) in which a shaft-shaped portion provided on the frame of the ADF <NUM> is engageable. The rotation guide <NUM> is rotatable between a position for guiding a lower surface of the original fed along the original conveying passage P1 (see <FIG>, hereinafter, this position is referred to as a closed position) and a position moved upward from the closed position (see <FIG>, hereinafter, this position is referred to as an open position). The closed position is a position (third position) where the rotation guide <NUM> covers the reading unit <NUM> as viewed from above, and the open position is a position (fourth position) where the rotation guide <NUM> exposes the reading unit <NUM> to the outside as viewed from above. The rotation guide <NUM> is held at the closed position by engaging a fixing portion 141d, provided at a free end portion thereof, with a conveying guide <NUM> fixed to the ADF main body 10B.

In a state in which the rotation guide <NUM> is positioned at the closed position, the pressing surface 141a of the rotation guide <NUM> contacts the resin cover 114a of the pressing portion <NUM>. Then, by elasticity of the compression spring 114b generated by pressing of the resin cover 114a, the reading unit <NUM> is pressed toward the shading plate <NUM>. By this, a position of the reading unit <NUM> with respect to the sheet thickness direction D2 is stabilized, so that this contributes to reading of the image information with high accuracy.

The reading unit <NUM> includes a shaft portion <NUM> rotatably supported by the frame of the ADF <NUM>, and is rotatable about another rotational axis A2 (third rotational axis) different from the rotational axis A1 of the rotation guide <NUM>. Incidentally, the supporting portion is not limited to the shaft portion <NUM> when the supporting portion is capable of supporting the reading unit <NUM>, and the read frame <NUM> may be provided with a hole (bearing portion) with which a shaft-shaped portion provided to the frame of the ADF <NUM> is engageable. The reading unit <NUM> is rotatable between a position where the image information is readable from the original fed along the original conveying passage P1 (see <FIG>, hereinafter, this position is referred to as a reading position) and a position where the glass <NUM> is exposed to the outside (see <FIG>, hereinafter, this position is referred to as a maintenance position). The reading position is a position (first position) of the reading unit <NUM> where the glass <NUM> which is a transparent member is in a state opposing the original conveying passage P1, and the maintenance position is a position (second position) of the reading unit <NUM> where the glass <NUM> is in an exposed state as viewed from the outside of the ADF <NUM>.

In a state in which the reading unit <NUM> is positioned at the reading position, the glass <NUM> opposes the shading plate <NUM> or the base conveying guide <NUM> through the original conveying passage P1 and is hidden behind the reading frame <NUM> as viewed from above with respect to the vertical direction. The maintenance position is a position of the reading unit <NUM> where at least a part (preferably a range encompassing a reading range of the CIS <NUM> or entirety of the glass <NUM>) of the glass <NUM> is exposed to the outside when the ADF <NUM> is viewed in a predetermined direction (for example, from above with respect to the vertical direction).

The shaft portion <NUM> is provided so as to project from opposite end portions of the reading frame <NUM> toward the outside in the X-direction (longitudinal direction), and is held by a holding portion B1 provided. Accordingly, the rotational axis A1 of the rotation guide <NUM> and the rotational axis of the reading unit <NUM> is substantially parallel to each other and substantially extend in the X-direction. The holding portion B1 is a recessed portion (opening) rotatably holding the shaft portion <NUM>, and the holding portion B1 in this embodiment is an elongated circular hole (groove portion) extending in the sheet thickness direction D2. The holding portion B1 as the elongated circular hole is, for example, provided on a side plate (plate-like member extending in the Y-direction and the Z-direction on a side out of an original passing region with respect to the X-direction) constituting the frame of the ADF <NUM>.

The rotational axis A1 of the rotation guide <NUM> is provided at an end portion of the rotation guide <NUM> on one end side (right-hand side of <FIG>) with respect to the Y-direction, and on the other hand, the shaft portion <NUM> in this embodiment is provided at an end portion of the reading unit <NUM> on the other end side (left-hand side of <FIG>) with respect to the Y-direction and on an upper side with respect to the Z-direction. For this reason, the reading unit <NUM> is rotated counterclockwise (in a first rotational direction) in <FIG> from the reading position toward the maintenance position, and on the other hand, the rotation guide <NUM> is rotated clockwise (in a second rotational direction) in <FIG> from the closed position toward the open position. Thus, when a constitution in which the rotational direction of the rotation guide <NUM> and the rotational direction of the reading unit <NUM> are opposite to each other is employed, there is also an advantage such that a rotation range of the reading unit <NUM> is easily ensured without being influenced by the rotation guide <NUM> in the open position. Incidentally, the rotational direction of the rotation guide <NUM> during the open thereof is opposite to a rotational direction of the upper portion cover <NUM>.

Next, the arm <NUM> will be described. The arm <NUM> is a member which is rotatably supported by the frame of the ADF <NUM> and which moves the reading unit <NUM> from the reading position to the maintenance position by being rotated in interrelation with rotation of the rotation guide <NUM> from the closed position to the open position. That is, the arm <NUM> is an example of an interrelating mechanism for moving the reading unit <NUM> in interrelation with the rotation of the rotation guide <NUM>. The arm <NUM> in this embodiment is a member which is rotated about the rotational axis A1 common to the arm <NUM> and the rotation guide <NUM> and which is rotatable independently of the rotation guide <NUM>.

As shown in <FIG>, the rotation guide <NUM> is provided with an arm contact portion 141b, and the arm <NUM> is provided with a contacted portion 131e to which the arm contact portion 141b is contactable. In a state in which the rotation guide <NUM> is positioned in the closed position and the reading unit <NUM> is positioned in the reading position, the arm contact portion 141b is spaced from the contacted portion 131e. Further, on a free end side of the arm <NUM>, arc profiles 131a, 131b and 131c as contact portions for urging (pressing) the reading unit <NUM>. Details of the arc profiles 131a, 131b and 131c will be described later.

In this embodiment, a constitution in which the arm <NUM> is interrelated with the rotation guide <NUM> only within an integral range and in which a rotation range of the arm <NUM> is narrower than a rotation range of the rotation guide <NUM> is employed. Specifically, at the closed position of the rotation guide <NUM>, the arm contact portion 141b of the rotation guide <NUM> does not contact the arm <NUM>, and at an intermediary position during rotation of the rotation guide <NUM> toward the open position, the arm contact portion 141b contacts the arm <NUM> (<FIG>). For this reason, compared with the case where the arm <NUM> is rotated integrally with the rotation guide <NUM>, a rotation locus of the arm <NUM> becomes small, so that a space required for disposing the arm <NUM> therein can be made small.

An operation in which the reading unit <NUM> is moved from the reading position to the maintenance position when a maintenance operation is performed will be described. Incidentally, an operator (user or maintenance person) opens the upper portion cover <NUM> in advance by rotating the upper portion cover <NUM> upward from the closed position shown in <FIG>.

First, in the state shown in <FIG>, in order to ensure a rotation space of the reading unit <NUM>, the operator holds the rotation guide <NUM> and then rotates the rotation guide <NUM> about the rotational axis A1 in the clockwise direction in <FIG>. Thus, as shown in <FIG>, not only the rotation guide <NUM> is spaced upward from the reading unit <NUM> but also the arm contact portion 141b approaches the contacted portion 131e of the arm <NUM>.

When the rotation guide <NUM> is further rotated, as shown in <FIG>, the arm contact portion 141b contacts the contacted portion 131e of the arm <NUM>, so that the arm <NUM> is rotated about the rotational axis 1A in the clockwise direction in <FIG>. By the rotation of the arm <NUM>, the arc profiles 131a and 131c provided on the free end side of the arm <NUM> contact and urge (press) the reading unit <NUM>, and thus rotate the reading unit <NUM> about the shaft portion <NUM> in the counterclockwise direction in <FIG>.

By this, the reading unit <NUM> is moved from the reading position shown in <FIG> to the maintenance position shown in <FIG>.

The operator is capable of easily performing an operation such as cleaning of the glass <NUM> or the like for the reading unit <NUM> moved to the maintenance position. The rotation guide <NUM> can be constituted so that the reading unit <NUM> is held at the maintenance position through the arm <NUM> by being retained at the open position, for example, by a self-weight thereof. Incidentally, as described later specifically, when the reading unit <NUM> reaches the maintenance position, the pressing portion <NUM> of the reading unit <NUM> abuts against an abutment surface 142a (<FIG>) of the conveying guide <NUM> fixed to the frame of the ADF main body 10A.

When the operation such as the cleaning of the glass <NUM> or the like is ended, in the state of <FIG>, the operator rotates the rotation guide <NUM> in the counterclockwise direction in <FIG> from the open position toward the closed position. Then, the arm <NUM> is rotated in the counterclockwise direction in <FIG> with the rotation of the rotation guide <NUM>. Further, the reading unit <NUM> is rotated in the clockwise direction in <FIG> from the maintenance position toward the reading position while being supported by the arm <NUM>. Then, when the rotational guide <NUM> reaches the closed position, the reading unit <NUM> is returned to the state of <FIG> in which the reading unit <NUM> is held at the reading position. That is, in this embodiment, the reading unit <NUM> is moved from the reading position to the maintenance position in interrelation with the opening operation of the rotation guide <NUM>, and is moved from the maintenance position to the reading position in interrelation with the closing operation of the rotation guide <NUM>.

Thus, the reading unit <NUM> is constituted so as to be rotatable about the rotational axis different from the rotational axis of the rotation guide <NUM>, so that when the reading unit <NUM> is moved for performing the cleaning of the glass <NUM> or the jam clearance, the impact exerted on the reading unit <NUM> can be reduced.

Further, in this embodiment, the holding portion B1 on a mating side (frame side of the ADF <NUM>) to the shaft portion <NUM> of the reading unit <NUM> is constituted as the elongated circular hole extending in the sheet thickness direction. In order to make the reading unit <NUM> rotatable separately from the rotation guide <NUM>, the holding portion B1 may also be constituted as a cylindrical hole corresponding to the shaft portion <NUM>. However, in this embodiment, the holding portion B1 is constituted as the elongated circular hole, so that in addition to rotation of the reading unit <NUM>, movement of the reading unit <NUM> in the sheet thickness direction D2 is allowed. By this, while regulating a positional deviation of the reading unit <NUM> in the sheet feeding direction D <NUM>, a variation in position of the reading unit <NUM> due to a part tolerance or the like of the ADF <NUM> can be absorbed by movement of the shaft portion <NUM>. The variation in position of the reading unit <NUM> is absorbed, so that the glass <NUM> can be more stably positioned relative to the shading plate <NUM> through the gap sheet <NUM>.

Further, as indicated by an arrow in <FIG>, in a state in which the reading unit <NUM> is rotated to the maintenance position, corresponding to a length of the holding portion B1, the reading unit <NUM> can be raised, and therefore, an operation property such as a maintenance property can be improved. At this time, when the abutment surface 142a of the conveying guide <NUM> is constituted as an inclined surface with inclination along the holding portion B1, the abutment surface 142a also functions as a guide when the reading unit <NUM> is raised. Incidentally, in this embodiment, a constitution in which the longitudinal direction of the elongated circular hole which is the holding portion B1 substantially coincides with the sheet thickness direction D2 of the reading unit <NUM> at the reading position was employed. The holding portion B1 is not limited thereto, but may also be an elongated circular hole extending in a direction, different from the sheet thickness direction D2, within directions crossing the sheet feeding direction D1 as viewed in the X-direction.

Next, a wiring path to the reading unit <NUM> and an advantage thereof in this embodiment will be described.

As described above, the reading unit <NUM> is electrically connected to the controller 2C (<FIG>) of the original reading apparatus <NUM> through the electric wire <NUM>. The electric wire <NUM> is not only a signal line for transmitting, to the controller 2C, the image information read by the reading unit <NUM> but also an electric power line for supplying electric power to the reading unit <NUM>. In this embodiment, as the electric wire <NUM>, a flexible flat cable (FFC) is used.

As shown in <FIG> and <FIG>, the electric wire <NUM> is connected to the sensor substrate 112c inside the reading unit <NUM> and is led out to the outside of the reading unit <NUM> through an opening (outlet <NUM>) provided in the reading frame <NUM>. On the outside side of the reading unit <NUM>, the electric wire <NUM> is wired inside the ADF main body 10A while being guided by a guiding member mounted on the frame of the ADF <NUM> and is connected to the controller 2C of the scanner portion <NUM>. Accordingly, the electric wire <NUM> includes an inner unit portion 150a held in the reading unit <NUM>, a main body-side portion 150b held by the frame of the ADF main body 10A, and an intermediary portion 150C connecting the inner unit portion 150a and the main body-side portion 150b. The intermediary portion 150c is a portion between the outlet <NUM> of the reading unit <NUM> and an inlet <NUM> (opening for receiving the electric wire <NUM> or guiding member for holding the electric wire <NUM>) on the ADF main body 10A. Incidentally, in order to facilitate flexure of the intermediary portion 150c, the electric wire (FFC) <NUM> is disposed so that a widthwise direction of the electric wire <NUM> in the intermediary portion 150c is substantially parallel to the X-direction which is a main scan direction of the reading unit <NUM>.

When the reading unit <NUM> which is a movable member relative to the frame of the ADF main body 10A is moved, the electric wire <NUM> is flexed, so that movement of the reading unit <NUM> is allowed. That is, when the reading unit <NUM> is rotated from a reading position shown in <FIG> to a maintenance position shown in <FIG>, principally the intermediary portion 150c of the electric wire <NUM> is flexed by following a change in attitude of the reading unit <NUM>, so that the rotation of the reading unit <NUM> is allowed. Further, as shown in <FIG>< when the reading unit <NUM> positioned in the maintenance position is raised along the holding portion B1, the intermediary portion 150c of the electric wire <NUM> extends (by which flexure due to an excessive length is eliminated), so that upward movement of the reading unit <NUM> is allowed.

Here, in this embodiment, by employing a constitution in which the reading unit <NUM> is rotatable separately form the rotation guide <NUM>, stress exerted on the electric wire <NUM> when the reading unit <NUM> is rotated can be reduced. This will be described below.

As shown in <FIG>, the electric wire <NUM> is led out from an inside to an outside the reading unit <NUM> through the neighborhood of the rotational axis A2 of the reading unit <NUM>. As viewed in the X-direction, a distance from the reading unit <NUM> to the outlet <NUM> through which the electric wire <NUM> is led out is shorter than at least a distance from the rotational axis A1 (second rotational axis) of the rotation guide to the outlet <NUM>. For that reason, compared with the case where the reading unit <NUM> is mounted on the rotation guide <NUM>, a movement amount of the outlet <NUM> when the reading unit <NUM> is rotated becomes small. Further, the neighborhood of the rotational axis A2 may preferably refers specifically to the case where the electric wire <NUM> passes through a position of the rotational axis A2 overlaps with the shaft portion <NUM> in a state in which these portions are viewed in the X-direction. Further, an arrangement such that of four corner portions of the reading frame <NUM> having a substantially rectangular shape as viewed in the X-direction, one corner portion closest to the outlet <NUM> through which the electric wire <NUM> is led out and one corner portion closest to the shaft portion <NUM> are the same is suitable.

Thus, in the case where the electric wire <NUM> is wired through the neighborhood of the rotational axis A2 of the reading unit <NUM>, when the reading unit <NUM> is rotated about the rotational axis A2, the electric wire <NUM> is flexed principally in the neighborhood of the rotational axis A2 (see <FIG>). That is, the electric wire <NUM> is flexed so that the inner unit portion 150a of the electric wire <NUM> is rotated about the neighborhood of the rotational axis A2 as a supporting point. For that reason, a fluctuation in distance from the outlet <NUM> of the electric wire <NUM> on the reading unit <NUM> side to the inlet <NUM> of the electric wire <NUM> on the ADF main body 10A side is small. When this fluctuation is large, there is a liability that the electric wire <NUM> is broken or disconnected by tension. For that reason, it would be considered that an excessive length of the intermediary portion 150c is increased by taking a fluctuation amount into consideration, but when the excessive length of the intermediary portion 150c is increased, this increase leads to an increase in cost and upsizing of the apparatus. On the other hand, in this embodiment, the fluctuation amount of the distance from the outlet of the electric wire <NUM> on the reading unit <NUM> side to the inlet of the electric wire <NUM> on the ADF main body 10A side is small, and therefore, even when the excessive length of the intermediary portion 150c is set at a small value, breakage or the like does not readily occur, so that the increase in cost and upsizing of the apparatus can be prevented.

Incidentally, in the case where a constitution in which the reading unit <NUM> is rotated integrally with the rotation guide <NUM> is employed, wiring of the electric wire <NUM> through the neighborhood of the rotational axis A2 becomes difficult. This is attributable to the following circumstances. First, the conveying guide for guiding the sheet, such as the rotation guide <NUM> is a relatively large member extending along the sheet conveying passage. For that reason, when such a large member is intended to be rotated, it is natural that the rotational axis of the conveying guide is disposed in the neighborhood of an upstream end or a downstream end of the conveying guide with respect to the feeding direction of the sheet to be guided. On the other hand, the reading unit is disposed at a position (below the rotation guide <NUM> in the case of the reading unit <NUM>) apart from the guiding surface of the conveying guide so as not to prevent the feeding of the sheet, and therefore, it becomes difficult that the outlet of the electric wire from the reading unit is disposed in the neighborhood of the rotational axis of the conveying guide. Further, in the neighborhood of the conveying guide, the feeding roller for feeding the sheet is disposed in many cases, so that when the reading unit is intended to be disposed while avoiding interference with the feeding roller, it becomes further difficult that the outlet of the electric wire from the reading unit is disposed in the neighborhood of the rotational axis of the conveying guide. With an increasing distance of the outlet of the electric wire, from the reading unit, from the rotational axis of the conveying guide, a fluctuation amount of the distance from the outlet of the downstream on the reading unit side to the inlet of the electric wire on the ADF main body side when the conveying guide is rotated becomes large. As a result, a breakage risk of the electric wire <NUM> arises.

On the other hand, in this embodiment, the reading unit <NUM> employs a mechanism rotatable separately from the rotation guide <NUM>, and therefore, the electric wire <NUM> can be wired through the neighborhood of the rotational axis A2 of the reading unit <NUM>. Further, the rotational axis A2 of the reading unit <NUM> can be disposed below the guiding surface of the rotation guide <NUM>. As a result, as described above, the breakage of the electric wire <NUM> can be made hard to occur.

Next, a constitution in which an operating property when the reading unit <NUM> is moved while being made rotatable in a wide rotation range is capable of being improved will be described using <FIG> and <FIG>.

The reading unit <NUM> assumes an attitude in the reading position such that the glass <NUM> faces downward with respect to the Z-direction and assumes an attitude in the maintenance position such that the glass <NUM> is exposed to the outside as viewed from above with respect to the Z-direction. That is, in this embodiment, the transparent member faces downward with respect to the vertical direction in a state in which the reading unit is positioned in the first position and faces upward with respect to the vertical direction in a state in which the reading unit is positioned in the second position.

When a degree of inclination of the glass <NUM> relative to the horizontal direction in the reading position is excessively large, a degree of flexure of the original conveying passage P1 becomes large, so that feeding of thick paper or the like becomes difficult, and therefore, an angle of the inclination of the glass <NUM> is, for example, <NUM> degrees or less, preferably <NUM> degrees or less. For that reason, the reading unit <NUM> is constituted so as to be rotatable between the read position and the maintenance position with a rotation range of, for example, <NUM> degrees or more, preferably <NUM> degrees or more, more preferably <NUM> degrees or more.

In the case where the reading unit <NUM> is rotated within such a rotation range, in a constitution in which an operator directly puts one's hand on the reading unit <NUM>, the hand is liable to be caught between the rotated reading unit <NUM> and another portion of the ADF <NUM>, so that there was room for improvement in operating property.

As described above, in this embodiment, the free end portion of the arm <NUM> interrelated with the rotation of the rotation guide <NUM> is contacted to the reading unit <NUM> from below, so that the reading unit <NUM> is rotated in interrelation with the rotation guide <NUM> (see <FIG> and <FIG>). At this time, the arm <NUM> is rotated in a rotational direction opposite to the rotational direction of the reading unit <NUM>, so that the reading unit <NUM> is moved from the reading position to the maintenance position while changing a contact position of the arm <NUM> with the reading unit <NUM>. For this reason, the operating property can be improved while enabling the rotation of the reading unit <NUM> within a wide rotation range.

Further, the reading unit <NUM> can be made movable from the reading position to the maintenance position with a small operating force to the extent possible, so that an operation load can be alleviated. In the following, this will be specifically described.

<FIG> shows a positional relationship between the reading unit <NUM>, the rotational axis A1 of the arm <NUM>, and the rotational axis A2 of the reading unit <NUM> when the arm <NUM> is first contacted to the reading unit <NUM>. In order to rotate the reading unit <NUM> in the counterclockwise direction by the contact of the arm <NUM> from below, it is efficient to bring the arm <NUM> into contact with the first contact surface 110a which is a surface (where the glass <NUM> is disposed) on a lower side of the reading unit <NUM> in the reading position.

Then, in order to consider that the arm <NUM> is contacted at which position of the first contact surface <NUM>10a, three points a, b and c will be considered. A chain double-dashed line passing through each of the points is a rotation locus about the rotational axis A1 for an associated point, and an arrow represents a tangential direction (direction of a load when the reading unit <NUM> is pressed at the associated point) thereof.

In the case where the arm <NUM> is contacted to the reading unit <NUM> at the point a, a load direction substantially extends toward the rotational axis A2 of the reading unit <NUM>, and therefore, efficiency is poor for rotating the reading unit <NUM>. In the case where the arm <NUM> is contacted to the reading unit <NUM> at the point c, rather, moment in the clockwise direction in <FIG> which is a direction opposite to a direction in which the operator intends to rotate the reading unit <NUM> acts on the reading unit <NUM>. On the other hand, as at the point b, in the case where the arm <NUM> is contacted to the reading unit <NUM> at a position, on the first contact surface <NUM>10a, apart from the rotational axis A2 on a right-hand side in the figure, the reading unit <NUM> is rotated even when the load required to press the reading unit <NUM> by the arm <NUM> is relatively small.

<FIG> shows a maximum angle at which the reading unit <NUM> can be rotated by pushing the first contact surface 110a from below. If the arm <NUM> is contacted to the first contact surface 110a at a point d, when the reading unit <NUM> is rotated to a position where the first contact surface 110a is vertically disposed, at the point d, the arm <NUM> cannot further press the reading unit <NUM>. In order to further rotate the reading unit <NUM>, as shown at a point e, a constitution in which the arm <NUM> contacts and presses the reading unit <NUM> at the second contact surface 110b different from the first contact surface 110a is employed.

In this embodiment, in view of the above, a constitution in which the arm <NUM> is provided with the two contact portions (131a, 131c) and in which the two contact portions are successively contacted to the first contact surface 110a and the second contact surface 110b, respectively, is employed.

In the following, such a constitution will be described. As shown in <FIG>, at the free end portion of the arm <NUM> in this embodiment, the three arc profiles 131a, 131b and 131c are provided.

From the rotational axis A1 toward an outside with respect to a radial direction, these arc profiles are referred to as a first arc profile 131a, a second arc profile 131b, and a third arc profile 131c. The first arc profile 131a and the third arc profile 131b are arcuately curved surfaces which are each projected toward a downstream side of the rotational direction (the clockwise direction in <FIG>) of the arm <NUM> when the arm <NUM> presses the reading unit <NUM>. The first arc profile 131a is a first projection for pressing the first contact surface 110a (first surface) of the reading unit <NUM>. The third arc profile 131c is a third projection for pressing the second contact surface 110b (second surface) of the reading unit <NUM>. The second arc profile 131b is an arcuately curved surface which is concaved between the first arc profile 131a and the third arc profile 131c and which forms a space for receiving a corner portion 110c between the first contact surface 110a and the second contact surface 110a. Incidentally, in this embodiment, the first contact surface 110a and the second contact surface 110c are adjacent two surfaces (surfaces crossing perpendicularly each other) of the reading unit <NUM> which has a substantially rectangular shape as viewed in the X-direction, but surfaces extending in directions crossing each other at an angle different from a right angle may be the first surface and the second surface, respectively.

In this embodiment, the first contact surface 110a of the reading unit <NUM> is a surface of the glass sheet <NUM> (gap forming member) sticked to the glass <NUM>. The arm <NUM> is prevented from directly contacting the glass <NUM>, whereby a possibility that the glass <NUM> is changed is reduced. Incidentally, as shown in <FIG>, a contact position of the arm <NUM> with the gap sheet <NUM> is deviated from an abutment region of the shading plate <NUM> against the gap sheet <NUM> in the X-direction. For that reason, even when the surface of the first contact surface 110a of the gap sheet <NUM> to which the arm <NUM> is repetitively contacted is roughened, accuracy of a gap width (range) formed between the glass <NUM> and the shading plate <NUM> is not lowered.

As shown in <FIG>, when the arm <NUM> is rotated in interrelation with the rotation of the rotation guide <NUM>, first, the first arc profile 131a contacts the first contact surface 110a of the reading unit <NUM> and causes the reading unit <NUM> to start to rotate from the reading position. At this time, the third arc profile 131c does not contact the second contact surface 110b of the reading unit <NUM>.

When the arm <NUM> is further rotated and thus an angle of the reading unit <NUM> reaches a predetermined angle, the third arc profile 131c contacts the second contact surface 110b, and the first arc profile 131a is separated from the first contact surface 110a. Then, the third arc profile 131c presses the second contact surface 110b, so that as shown in <FIG>, the reading unit <NUM> is rotated to the maintenance position.

When the reading unit <NUM> reaches the maintenance position, as shown in <FIG>, the pressing portion <NUM> of the reading unit <NUM> abuts against the abutment surface 142a of the conveying guide <NUM> fixed to the frame of the ADF main body 10A. At this time, by elasticity of the elastic member (compression spring 114b) provided on the pressing portion <NUM>, an impact of abutment of the reading unit <NUM> against the conveying guide <NUM> is alleviated. That is, the pressing portion <NUM> performs not only positioning action on the reading unit <NUM> during the image reading but also a function of a buffer when the reading unit <NUM> is moved to the maintenance position.

Thus, a constitution in which the contact position between the arm <NUM> and the reading unit <NUM> is switched depending on the rotation angle of the reading unit <NUM> is employed, so that while the reading unit <NUM> is made rotatable in the wide rotation range, an operation load can be alleviated. Further, a recessed arc profile 131c is provided between the two projections of the arm <NUM> contacting the first contact surface 110a and the second contact surface 110b of the reading unit <NUM>, and therefore, the arm <NUM> and the reading unit <NUM> are not put in a locked state by the two projections. That is, the corner portion 110c between the first contact surface 110a and the second contact surface 110b is accommodated in a space inside the arc profile <NUM>1c, so that the state between the arm <NUM> and the reading unit <NUM> is smoothly shifted from a contact state between the first arc profile 131a and the first contact surface 110a to a contact state between the third arc profile 131c and the second contact surface 110b.

Further, in this embodiment, the three arc profiles 131a, 131b and 131c are smoothly connected to each other (i.e., a tangential direction is not changed discontinuously), and therefore, even when the contact position of the reading unit <NUM> is switched between the respective profiles, smooth rotation can be realized.

Incidentally, in this embodiment, the case where each of the two projections and the recess between the two projections is constituted by the arcuate curves was described, but these portions may also be constituted as curves other than the arcuate curves.

In the embodiment <NUM>, the constitution in which the reading unit <NUM> is rotated in interrelation with opening and closing of the rotation guide <NUM> through the arm <NUM> moved in interrelation with the opening and closing of the rotation guide <NUM> was described. The present invention is not limited thereto, and a constitution as shown in <FIG> in which the arm <NUM> is not provided and in which the operator directly rotates the reading unit <NUM> by one's hand(s) may be employed. In this case, in order to move the reading unit <NUM> to the maintenance position, the operator first rotates the rotation guide <NUM> from the closed position to the open position while holding the rotation guide <NUM>, and then rotates the reading unit <NUM> from the reading position to the maintenance position while holding the reading unit <NUM>.

Further, as another constitution in which the reading unit <NUM> is rotated in interrelation with the opening and closing of the rotation guide <NUM>, a constitution in which a part of the rotation guide <NUM> is contacted to the reading unit <NUM> in a manner such that the arm <NUM> is formed integrally with the rotation guide <NUM> may be employed. Incidentally, in the embodiment <NUM>, the constitution in which the arm <NUM> is rotatable relative to the rotation guide <NUM> and in which the rotation range of the arm <NUM> is narrower than the rotation range of the rotation guide <NUM> is employed, and therefore, as described above, downsizing of the apparatus can be realized compared with this modified embodiment.

In the embodiment <NUM>, the case where the arm <NUM> is disposed on one side of the reading unit <NUM> and the rotation guide <NUM> with respect to the X-direction was described, but the arm <NUM> may be disposed on each of opposite sides with respect to the X-direction. In that case, a torsional load is not readily exerted on the reading unit <NUM> and the rotation guide <NUM>.

An embodiment <NUM> will be described using <FIG>. This embodiment is different from the embodiment <NUM> in that a constitution in which in a state in which the rotation guide <NUM> is moved to the open position in advance, the operator holds and operates the operating portion of the arm <NUM> and thus rotates the reading unit <NUM> is employed. In the following, elements represented by reference numerals or symbols common to the embodiments <NUM> and <NUM> are regarded as those having substantially the same constitutions and functions, and an element different from those in the embodiment <NUM> will be principally described.

As shown in <FIG>, the arm <NUM> in this embodiment is provided with an arm operating portion 131d as an operating portion (lever, handle). The arm operating portion 131d is disposed, for example, so as to project upward from the guiding surface of the rotation guide <NUM> on a front side of the image forming apparatus <NUM> relative to the rotation guide <NUM> in order to facilitate access by the operator in a state in which the upper portion cover <NUM> is opened. The arm operating portion 131d will be described as being rotated integrally with another portion of the arm <NUM>, but may be connected rotatably relative to the aforementioned another portion so as to be interrelated with the aforementioned another portion only in a predetermined rotation range.

In the case where the reading unit <NUM> is moved from the reading position to the maintenance position during a maintenance operation, the operator opens the upper portion cover <NUM> in advance, and then moves the rotation guide <NUM> to the open position. In this state, the operator puts one's hand on the arm operating portion 131a and rotates the arm <NUM> in the clockwise direction in <FIG>.

Then, as shown in <FIG> and <FIG>, the arc profiles 131a and 131c provided on the free end portion side of the arm <NUM> contacts and presses the reading unit <NUM> and rotates the reading unit <NUM> about the shaft <NUM> in the counterclockwise direction in the figures. By this, the reading unit <NUM> is moved from the reading position shown in <FIG> to the maintenance position shown in <FIG>. Thus, the reading unit <NUM> is constituted so as to be rotatable independently of the rotation guide <NUM>, so that it is possible to reduce impact received by the reading unit <NUM> when the reading unit <NUM> is moved when cleaning of the glass <NUM> or the jam clearance is performed.

Further, in a process in which the arm <NUM> is rotated, similarly as in the embodiment <NUM>, to two arc profiles 131a and 131c provided on the arm <NUM> successively contact the first contact surface 110a and the second contact surface 110b. At this time, the operator may only be required to operate the arm operating portion 131d in the case where the reading unit <NUM> is moved to the maintenance position, so that a possibility that the operator's hand is caught between the reading unit <NUM> and ADF main body 10A is low. Accordingly, the operating property can be improved while making the reading unit <NUM> rotatable within a wide rotation range.

Incidentally, also in this embodiment, the reading unit <NUM> is constituted so as to be rotatable independently of the rotation guide <NUM>, so that a breakage risk of the electric wire <NUM> when the reading unit <NUM> is rotated is capable of being reduced.

An embodiment <NUM> will be described using <FIG> and <FIG>. This embodiment is different from the embodiment <NUM> in that in position of a rotational axis of the reading unit <NUM> and a rotational direction of the reading unit <NUM> are different from those in the embodiment <NUM>. In the following, elements represented by reference numerals or symbols common to the embodiments <NUM> and <NUM> are regarded as those having substantially the same constitutions and functions, and an element different from those in the embodiment <NUM> will be principally described.

As shown in <FIG>, the reading unit <NUM> includes the shaft portion <NUM> and is rotatable about a rotational axis A3 (third rotational axis) different from the rotational axis A1 of the rotation guide <NUM> as the conveying guide. In this embodiment, the rotational axis A3 of the reading unit <NUM> is provided on one side of the Y-direction of the reading unit <NUM> (negative side of the Y-direction) and at an end portion on an upper side of the Z-direction. That is, in this embodiment, the second rotational axis is provided at an upstream-side end portion of the conveying guide with respect to the sheet feeding direction (leftward direction in <FIG>) of the sheet guided by the conveying guide. The third rotational axis is provided at the upstream-side end portion of the reading unit with respect to the sheet feeding direction of the sheet guided by the conveying guide.

For this reason, the rotation guide <NUM> is rotated clockwise about the rotational axis A1 from the closed position toward the open position, and the reading unit <NUM> is rotated clockwise about the rotational axis A3 from the reading position to the maintenance position. Thus, even in a constitution in which the rotational directions of the rotation guide <NUM> and the reading unit <NUM> when the glass <NUM> as the transparent member is exposed to the outside are the same, it is possible to achieve effects similar to the effects of the embodiments <NUM> and <NUM>. Whether the rotational directions of the rotation guide <NUM> and the reading unit <NUM> are made the same direction or different directions is selected depending on a specific constitution of the ADF <NUM>, such as a positional relationship of these members with members provided at a periphery of these members, or the like.

Incidentally, in this embodiment, the position of the rotational axis A3 of the reading unit <NUM> is different from those in the embodiments <NUM> and <NUM>, and therefore, it is preferable that a wiring path of the electric wire <NUM> connected to the reading unit <NUM> is also changed from those in the embodiments <NUM> and <NUM>. As shown in <FIG>, the electric wire <NUM> is led out from the inside to the outside of the reading unit <NUM> through the neighborhood of the rotational axis A3 of the reading unit <NUM>. At this time, the electric wire <NUM> is different from the electric wire <NUM> in the embodiment <NUM>, and is led out to the negative side of the Y-direction (downstream side of the sheet feeding direction in the reading position) and then is guided and wired by a guiding member <NUM> provided on the frame of the ADF main body 10A.

A distance from the rotational axis A3 of the reading unit <NUM> to an outlet where the electric wire <NUM> is led out from the reading unit <NUM> is shorter than at least a distance from the rotational axis A1 of the rotation guide <NUM> to the outlet. Further, the neighborhood of the rotational axis A3 is suitable when the electric wire <NUM> passes through a position where the rotational axis A3 overlaps with the shaft portion <NUM> in a state in which the rotational axis A3 is viewed specifically in the X-direction. Further, it is suitable that of four corner portions of the reading frame <NUM> which has a substantially rectangular shape as viewed in the X-direction, one corner portion is closest to the outlet through which the electric wire <NUM> is led out and is closest to the shaft portion <NUM>.

Thus, in the case where the electric wire <NUM> is wired through the neighborhood of the rotational axis A3 of the reading unit <NUM>, when the reading unit <NUM> is rotated about the rotational axis A3, the electric wire <NUM> is principally flexed in the neighborhood of the rotational axis A3 (see <FIG>). For that reason, a fluctuation in distance from the outlet of the electric wire <NUM> on the reading unit <NUM> side to the inlet <NUM> (opening through which the electric wire <NUM> is received or a guiding member for holding the electric wire <NUM>) of the electric wire <NUM> on the ADF main body 10A side is small. Accordingly, even in the constitution of this embodiment, it is possible to reduce a possibility of breakage of the electric wire <NUM>.

An embodiment <NUM> will be described using <FIG>. This embodiment is different from the embodiment <NUM> in position of the rotational axis of the rotation guide <NUM> and the rotational direction of the rotation guide <NUM>. In the following, elements represented by reference numerals or symbols common to the embodiments <NUM> and <NUM> are regarded as those having substantially the same constitutions and functions, and an element different from those in the embodiment <NUM> will be principally described.

As shown in <FIG>, the rotation guide <NUM> as the conveying guide is provided rotatably about a rotational axis A4 (second rotational axis). The rotational axis A4 is provided at an end portion of the rotation guide <NUM> on a downstream side (left-hand side in <FIG>, positive side of the Y-direction) with respect to the sheet feeding direction of the sheet guided by the rotation guide <NUM>. That is, in this embodiment, the second rotational axis is provided at the downstream-side end portion of the conveying guide with respect to the sheet feeding direction of the sheet guided by the conveying guide. The third rotational axis is provided at a downstream-side end portion of the reading unit with respect to the sheet feeding direction of the sheet guided by the rotation guide.

For this reason, the rotation guide <NUM> is rotated counterclockwise about the rotational axis A4 in <FIG> from the closed position toward the open position, and the reading unit <NUM> is rotated counterclockwise about the rotational axis A2 in <FIG> from the reading position toward the maintenance position. Even in such a constitution, it is possible to obtain effects similar to the effects of the embodiments <NUM> and <NUM>.

A modified embodiment will be described using <FIG>. In this modified embodiment, the position of the rotational axis A4 of the rotation guide <NUM> and the rotational direction of the rotation guide <NUM> in the embodiment <NUM>, and the position of the rotational axis A3 of the reading unit <NUM> and the rotational direction of the reading unit <NUM> in the embodiment <NUM> are combined with each other. That is, in this modified embodiment, the second rotational axis is provided at the downstream-side end portion of the conveying guide with respect to the sheet feeding direction of the sheet guided by the conveying guide. The third rotational axis is provided at the upstream-side end portion of the reading unit with respect to the sheet feeding direction of the sheet guided by the conveying guide.

For this reason, the rotation guide <NUM> is rotated counterclockwise about the rotational axis A4 in <FIG> from the closed position toward the open position and the reading unit <NUM> is rotated clockwise about the rotational axis A3 in <FIG> from the reading position toward the maintenance position. Even in such a constitution, it is possible to obtain effects similar to the effects of the embodiments <NUM> and <NUM>.

An embodiment <NUM> will be described using <FIG> and <FIG>. This embodiment is different from the embodiment <NUM> in that a plurality of arm members are contacted to the first contact surface and the second contact surface of the reading unit. In the following, elements represented by reference numerals or symbols common to the embodiments <NUM> and <NUM> are regarded as those having substantially the same constitutions and functions, and an element different from those in the embodiment <NUM> will be principally described.

The ADF <NUM> in this embodiment includes an arm <NUM> as a first arm member and an arm <NUM> as a second arm. The arms <NUM> and <NUM> are rotatably supported by the frame of the ADF main body 10A and are rotated about the rotational axis A1. The arms <NUM> and <NUM> overlap with each other as viewed in the X-direction. Further, the arms <NUM> and <NUM> can be rotated by operating the arm operating portion 131d. Even in such a constitution, an effect similar to the effect of the embodiment <NUM> can be achieved.

In the case where the arm operating portion 131d is rotated in the clockwise direction from a state of <FIG>, first, the arm <NUM> is rotated and contacted to the first contact surface 110a of the reading unit <NUM>. Then, at the time when the arm <NUM> is rotated by a predetermined angle, the arm <NUM> starts rotation and is contacted to the second contact surface 110b of the reading unit <NUM>. By this, as shown in <FIG>, the reading unit <NUM> is rotated to the maintenance position. Thus, the arms <NUM> and <NUM> press a plurality of surfaces of the reading unit <NUM>, so that it is possible to realize rotation of the reading unit <NUM> in a wide rotation range. Further, by employing a constitution in which the two arms <NUM> and <NUM> which overlap with each other are interrelated with each other with a time difference, it is possible to reduce a space necessary to arrange the arms <NUM> and <NUM>.

An embodiment <NUM> will be described using <FIG> and <FIG>. This embodiment is different from the embodiment <NUM> in that a reading unit-side contact surface to which the arm member is contacted is made a curved surface and thus a rotation range of the reading unit is ensured. In the following, elements represented by reference numerals or symbols common to the embodiments <NUM> and <NUM> are regarded as those having substantially the same constitutions and functions, and an element different from those in the embodiment <NUM> will be principally described.

As shown in <FIG>, the reading unit <NUM> in this embodiment includes an arm contact surface 110d different from the surface on which the glass <NUM> is disposed. The arm contact surface 110d is substantially arcuate curved surface which projects toward an upstream side of the rotational direction (downstream direction in <FIG>) of the arm <NUM> in a state in which the arm contact surface 110d is viewed in the X-direction. On the other hand, a free end of the arm <NUM> is formed in a substantially linear shape along a rectilinear line passing through the rotational axis A1. The arm contact surface 110d is the curved surface which is substantially continuous at least between a first contact point d1 (<FIG>) and a second contact point d2 (<FIG>).

The first contact point d1 is a position where the reading unit <NUM> is contacted to the arm <NUM> in a state in which the reading unit <NUM> is positioned in the reading position. The second contact point d2 is a position where the reading unit <NUM> is contacted to the arm <NUM> in a state in which the reading unit <NUM> is positioned in the maintenance position.

When the arm <NUM> is rotated in the clockwise direction in <FIG>, the arm <NUM> rotates the reading unit <NUM> from the reading position to the maintenance position while continuously changing a contact position to the arm contact surface 110d from the first contact point d1 to the second contact point d2. Therefore, according to the constitution of this embodiment, even when the arm <NUM> is formed in a simple shape, an effect similar to the effect of the embodiment <NUM> can be obtained, so that a degree of design freedom can be enlarged.

In the above-described embodiments, the constitution in which the present invention is applied to the image reading apparatus installed at an upper portion of the apparatus main assembly of the image forming apparatus was described. The present invention is not limited thereto, and is also applicable to an image reading apparatus which is independent of an image forming apparatus.

According to the present invention, it is possible to facilitate cleaning of the glass surface of the reading unit.

Claim 1:
An image reading apparatus (<NUM>) for reading image information from a sheet, comprising:
a cover unit (<NUM>) provided rotatably about a first rotational axis and including an upper surface of said image reading apparatus (<NUM>);
a sheet conveying member (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) configured to convey the sheet along a sheet conveying passage (P1);
a conveying guide (<NUM>) provided rotatably about a second rotational axis different from the first rotational axis and configured to guide the sheet fed by said sheet conveying member (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>); and
a reading unit (<NUM>) which includes a transparent member (<NUM>) and a reading portion (<NUM>) configured to read, through said transparent member (<NUM>), an image on the sheet fed by said sheet conveying member (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>),
wherein said cover unit (<NUM>) is rotatable between a closed position where said cover unit (<NUM>) forms the sheet conveying passage (P1) in cooperation with said conveying guide (<NUM>) and an open position where the sheet conveying passage (P1) is open, characterized in that
the reading unit (<NUM>) is provided rotatably about a third rotational axis different from the first rotational axis and the second rotational axis,
wherein in a state in which said cover unit (<NUM>) is positioned in the open position, said transparent member (<NUM>) is exposed to an outside of said image reading apparatus (<NUM>) by rotation of said conveying guide (<NUM>) and said reading unit (<NUM>).