Paper feed cassette and image forming apparatus

Abstract

The present invention provides a cassette device that can automatically cover the upper surface of the extended cassette extension with a cassette cover. [Solution] The cassette device 3 includes a cassette extension 12 that slides relative to the cassette body 11, a cassette cover 13 that closes the upper surface of the cassette extension 12, a cover biasing member that biases the cassette cover 13 toward a protruding position P6, a cover locking part 15 that locks the cassette cover 13, and a lock release part 16 that engages with the cover locking part 15. When the shortened cassette extension 12 and the cassette body 11 are housed in the housing 2, the lock release part 16 does not engage with the cover locking part 15, and the cover locking part 15 holds the cassette cover 13 in the pushed-in position. When the extended cassette extension 12 and the cassette body 11 are housed in the housing 2, the lock release part 16 engages with the cover locking part 15, releasing the lock on the cassette cover 13, and the cassette cover 13 slides to the protruding position P6.

Description

Technical Field

[0001] The present invention relates to a paper feeding cassette and an image forming apparatus.

Background Art

[0002] There is known a paper feeding cassette capable of accommodating papers of different sizes (Patent Document 1). The housing of this paper feeding cassette is configured by combining a main body portion and a movable housing that can be expanded and contracted. A cassette cover is attached to the housing via a locking portion of the main body portion, and an auxiliary tray that can be expanded and contracted is provided on the cassette cover. When accommodating large-sized papers in the housing, after the user pulls out the movable housing with respect to the main body portion, the user then pulls out the auxiliary tray with respect to the cassette cover. As a result, a part of the upper surface of the opened movable housing where the movable housing is disengaged forward from the cassette cover can be covered with the auxiliary tray.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described technology, when accommodating large-sized papers (media) in the housing, the user has to manually pull out the auxiliary tray, which is inconvenient for the user. If printing is performed with the upper surface of the movable housing open without pulling out the auxiliary tray, there is a risk that the user may touch the papers in the housing during printing or that foreign matters such as dust may enter the housing.

[0005] The present invention provides a cassette device and an image forming apparatus that can automatically cover the upper surface of an extended cassette extension portion with a cassette cover in consideration of the above circumstances.

Means for Solving the Problems

[0006] The paper feed cassette of the present invention comprises: a cassette body that slides between a storage position in which it is housed in the housing of an image forming apparatus and an extension position in which it is pulled out from the housing; a cassette extension portion provided on the leading end side of the cassette body in the extension direction and constituting a media cassette that houses media together with the cassette body, and sliding between a shortened position in which it fits inside the cassette body to form a shortened media cassette and an extended position in which it extends in the extension direction; a cassette cover that slides between a pushed-in position in which it is pushed into the housing and positioned above the media cassette and a protruding position in which it protrudes out from the housing and closes the upper surface of the cassette extension portion positioned at the extension position; a cover biasing member that biases the cassette cover toward the protruding position; and a locking mechanism provided on the housing for the cassette cover. The cassette includes a cover locking portion and a release portion provided on the cassette body that can engage with the cover locking portion. When the cassette extension portion is in the shortened position, the release portion does not engage with the cover locking portion during the process of sliding the cassette body from the pull-out position to the storage position, and the cover locking portion locks the cassette cover and holds it in the pushed-in position against the biasing force of the cover biasing member. When the cassette extension portion is in the extended position, the release portion engages with the cover locking portion during the process of sliding the cassette body from the pull-out position to the storage position, releasing the locking of the cassette cover by the cover locking portion, and the cassette cover slides from the pushed-in position to the protruding position, biased by the cover biasing member.

[0007] In this case, the cover lock portion has a locking claw portion that slides between a locking position that locks the cassette cover when it is positioned in the push-in position and an unlocking position that releases the locking of the cassette cover, and a locking biasing member that biases the locking claw portion toward the locking position, the locking claw portion has a locking inclined surface which is one surface on the protruding side of the cassette cover and a locking locking surface which is one surface on the push-in side of the cassette cover, and the cassette cover has the locking locking surface of the locking claw portion positioned in the locking position when it is positioned in the push-in position The unlocking part has a locking projection that engages with the locking claw, and the unlocking part has a release pressing part that slides between a pressing position that presses the locking inclined surface of the locking claw, which is positioned in the locked position, to slide the locking claw to the unlocking position, and a non-pressing position that releases the pressure on the locking claw, which is positioned in the shortened position, and a release biasing member that biases the release pressing part toward the non-pressing position, and the cassette extension part has a sliding rail that can press the release pressing part toward the pressing position, and when the cassette extension part is positioned in the shortened position, the release The depressure portion is not pressed by the sliding rail, but is biased by the release biasing member and slides from the pressed position to the unpressed position, and does not press the locking claw portion in the process of sliding the cassette body from the pull-out position to the storage position, the locking surface of the locking claw portion engages the locking projection and holds the cassette cover in the pushed-in position, and when the cassette extension portion is positioned in the extension position, the release pressing portion is pressed by the sliding rail and slides from the unpressed position to the pressed position against the biasing force of the release biasing member, and the cassette In the process of sliding the main body from the pull-out position to the storage position, the locking inclined surface is pressed, the locking claw is slid from the locked position to the unlocked position against the biasing force of the locking biasing member, the cassette cover is positioned in the protruding position by the biasing force of the cover biasing member, the cassette extension is positioned in the shortened position, and the cassette cover is positioned in the protruding position, the cassette cover is pushed by the cassette body sliding from the pull-out position to the storage position and slides from the protruding position to the pushed-in position,The locking projection slides along the locking inclined surface, causing the locking claw to slide to the unlocked position, and then overcomes the locking inclined surface to engage with the locking surface.

[0008] The image forming apparatus of the present invention comprises a cassette device as described above, and an image forming apparatus for forming an image on the medium fed out from the medium cassette. [Effects of the Invention]

[0009] According to the present invention, the upper surface of the extended cassette extension can be automatically covered with a cassette cover. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view showing an image forming apparatus according to one embodiment of the present invention. [Figure 2] This is a plan view of a cassette device according to one embodiment of the present invention, showing the state in which the media cassette has been pulled out and the first media has been placed inside. [Figure 3] This is a plan view showing a cassette device according to one embodiment of the present invention, in which a media cassette containing a first medium is placed in a storage position. [Figure 4] This is a plan view of a cassette device according to one embodiment of the present invention, showing the state in which the media cassette has been pulled out and the second media has been placed inside. [Figure 5] This is a plan view showing a cassette device according to one embodiment of the present invention, in which a media cassette containing a second medium is placed in a storage position. [Figure 6] This is a perspective view showing the cassette cover, etc., of a cassette device according to one embodiment of the present invention. [Figure 7] This is a front view showing the cassette cover, etc., of a cassette device according to one embodiment of the present invention. [Figure 8] This is a front view showing the cover lock and unlock parts of a cassette device according to one embodiment of the present invention. [Figure 9]This is a plan view showing the cover lock and unlock parts of a cassette device according to one embodiment of the present invention. [Figure 10] This is a plan view showing the state immediately before the cassette cover is unlocked, relating to the cover lock and unlocking parts of a cassette device according to one embodiment of the present invention. [Figure 11] This is a plan view showing the cassette cover in an unlocked state, representing the cover lock and unlocking parts of a cassette device according to one embodiment of the present invention. [Figure 12] This is a side view (cross-sectional view) illustrating the movement of the cassette cover of a cassette device according to one embodiment of the present invention. [Figure 13] This is a plan view showing the process of returning the cassette cover to the pressed-in position, relating to a cover locking and unlocking section of a cassette device according to one embodiment of the present invention. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the attached drawings. In the drawings, Fr, Rr, L, R, U, and D indicate front, rear, left, right, top, and bottom, respectively. Furthermore, the front-to-back, left-to-right, and up-to-down directions are mutually orthogonal. While this specification uses terms to indicate direction and position, these terms are used for convenience of explanation and do not limit the technical scope of the present invention. Also, the shapes and dimensions of the members in each figure are not precise but are schematic representations for illustrative purposes.

[0012] [Image forming apparatus] Referring to Figure 1, an overview of the image forming apparatus 1 according to this embodiment will be described. Figure 1 is a perspective view showing the image forming apparatus 1.

[0013] The image forming apparatus 1 includes a housing 2 having an approximately rectangular parallelepiped appearance. The housing 2 includes, for example, a metal frame and an exterior member made of synthetic resin fixed to the frame (both not shown). The image forming apparatus 1 includes a cassette device 3 including a media cassette 10 for accommodating a medium 9 (for example, single-sheet paper, resin sheet, etc.), and an image forming device 4 for forming an image on the medium 9 fed out from the media cassette 10. Further, a discharge tray 5 for receiving the medium 9 on which an image is formed (printed) is provided on the upper surface of the housing 2.

[0014] The cassette device 3 is provided at the lower part of the housing 2. Specifically, a cassette accommodation chamber 6 for accommodating the media cassette 10 which is the main part of the cassette device 3 is formed at the lower part of the housing 2 (see FIG. 2 described later). The media cassette 10 is detachably accommodated in the cassette accommodation chamber 6 through an opening formed at the lower front part of the housing 2. The media cassette 10 is formed to be able to accommodate media 9 of different sizes.

[0015] In this specification, the “media 9 of different sizes” includes, for example, a small-sized media 9 such as A4 size and a relatively large-sized media 9 such as legal size. The relatively large-sized media 9 is formed longer in the slide direction of the media cassette 10 (front-rear direction in this embodiment) than the small-sized media 9. Further, in this specification, the small-sized media 9 is referred to as “first media 9A”, the relatively large-sized media 9 is referred to as “second media 9B”, and in the description common to the first media 9A and the second media 9B, it is simply referred to as “media 9” and only arithmetic numbers are attached to the reference signs.

[0016] The image forming device 4 is provided above the cassette accommodation chamber 6 (cassette device 3) inside the housing 2. The image forming device 4 includes a toner container, a photosensitive drum, a charging device, a developing device, a transfer roller, an optical scanning device, a fixing device, etc. (all not shown), and forms an image on the medium 9 by an electrophotographic method. The image forming device 4 forms an image on the medium 9 fed out from the media cassette 10 and discharges the medium 9 on which the image is formed to the discharge tray 5.

[0017] The image-forming device 4 may form a full-color image or a monochrome image on the medium 9. Furthermore, while the image-forming device 4 is described as an electrophotographic printer, it is not limited to this; for example, it could be an inkjet printer. Also, the image-forming device 4 is not limited to a printer; for example, it could be a facsimile or copier.

[0018] [Cassette player] Next, the cassette device 3 will be described in detail with reference to Figures 2 to 9. Figure 2 is a plan view showing the media cassette 10 pulled out and the first medium 9A stored inside. Figure 3 is a plan view showing the media cassette 10 containing the first medium 9A placed in storage position P1. Figure 4 is a plan view showing the media cassette 10 pulled out and the second medium 9B stored inside. Figure 5 is a plan view showing the media cassette 10 containing the second medium 9B placed in storage position P1. Figure 6 is a perspective view showing the cassette cover 13, etc. Figure 7 is a front view showing the cassette cover 13, etc. Figure 8 is a front view showing the cover lock part 15 and the lock release part 16, etc. Figure 9 is a plan view showing the cover lock part 15 and the lock release part 16, etc.

[0019] As shown in Figure 2, the cassette device 3 comprises a cassette body 11, a cassette extension 12, a cassette cover 13, a cover biasing member 14, a cover locking part 15, and a lock release part 16.

[0020] <Cassette unit> The cassette body 11 is formed in a roughly tray-like shape with the front and top surfaces open. On the bottom surface of the cassette body 11 are a cursor for aligning the edges of the media 9 and a lift plate for lifting the media 9 and bringing it into contact with the paper feed device (neither of which are shown). On the back surface of the cassette body 11 protrudes a positioning projection 20 that fits into a positioning recess 6A formed in the rear of the cassette storage chamber 6. When the positioning projection 20 fits into the positioning recess 6A, the cassette body 11 is positioned in the correct location within the cassette storage chamber 6 (see Figure 3).

[0021] Slide rails (not shown) are interposed between the left and right outer surfaces of the cassette body 11 and the left and right inner surfaces of the cassette storage chamber 6. The slide rails may include, for example, an outer rail fixed to the inner surface of the cassette storage chamber 6, an inner rail fixed to the outer surface of the cassette body 11, and an intermediate rail interposed between the outer rail and the inner rail. The cassette body 11 is supported so as to be slidable in the front-rear direction relative to the housing 2 via the pair of slide rails. In detail, the cassette body 11 slides between a storage position P1 (see Figure 3) where it is housed in the housing 2 and an extraction position P2 (see Figure 2) where it is pulled out (forward) from the housing 2.

[0022] The storage position P1 is the position that allows the medium 9 stored in the cassette body 11 (medium cassette 10) to be fed towards the imaging device 4, and the withdrawal position P2 is the position that allows the medium 9 to be replenished in the cassette body 11 (medium cassette 10). Furthermore, when the cassette body 11 is positioned in the storage position P1, the positioning projection 20 fits into the positioning recess 6A, restricting the rearward sliding of the cassette body 11 (see Figure 3). In addition, the structure that slidably supports the cassette body 11 in the housing 2 is not limited to slide rails; for example, bosses protruding from a pair of left and right outer surfaces of the cassette body 11 may slidably fit into slide grooves formed on a pair of left and right inner surfaces of the cassette storage chamber 6 (not shown).

[0023] <Cassette extension> As shown in Figure 2, the cassette extension 12 is provided on the front side (the leading edge in the pulling direction) of the cassette body 11 and together with the cassette body 11 constitutes a media cassette 10 that houses the media 9. The cassette extension 12 has an extension body 21 which is formed in a substantially tray shape with the back and top surfaces open, and an extension adjustment part 22 provided in the center of the extension body 21 in the left-right direction.

[0024] The front of the extension body 21 forms the exterior of the lower front of the housing 2 when the media cassette 10 is housed in the housing 2 (see Figure 1). As shown in Figures 2 and 4, a pair of sliding rails 23 are provided protruding from the left and right outer surfaces of the extension body 21. The pair of sliding rails 23 are slidably supported by a plurality of guide protrusions 24 that protrude from the left and right inner surfaces of the cassette body 11. As shown in Figure 4, the left side surface of the left sliding rail 23 has a sliding inclined surface 23A and a sliding straight surface 23B, which come into contact with the release pressing part 42 of the lock release part 16, which will be described later. The sliding inclined surface 23A is formed on the front side of the sliding rail 23 and is inclined to the left from the front end toward the rear. The sliding straight surface 23B is the left side surface of the sliding rail 23 that extends backward from the sliding inclined surface 23A.

[0025] The extension adjustment section 22 is integrally provided with the bottom surface of the extension body section 21 and extends rearward from the bottom surface. The extension adjustment section 22 is slidably fitted into an adjustment guide groove 25 formed in the center of the cassette body 11 in the left-right direction.

[0026] The cassette extension 12 is supported so as to be slidable in the front-rear direction relative to the cassette body 11 by guiding the sliding rail 23 to a plurality of guide protrusions 24 and guiding the extension adjustment part 22 to the adjustment guide groove 25. In detail, the cassette extension 12 slides between a shortened position P3 (see Figure 2) where it is inserted into the cassette body 11 to form a shortened media cassette 10, and an extended position P4 (see Figures 4 and 5) where it is extended forward (in the pulling direction) to form a media cassette 10. The extension adjustment part 22 and the adjustment guide groove 25 are provided with temporary stoppers (not shown) that limit the sliding of the cassette extension 12 when it is positioned at the shortened position P3 or the extended position P4. The user slides the cassette extension 12 to the extended position P4 by pulling it at the shortened position P3 with a force exceeding the load of the temporary stopper, and slides it to the shortened position P3 by pushing it at the extended position P4 with a force exceeding the load of the temporary stopper. Furthermore, the structure for slidably supporting the cassette extension 12 on the cassette body 11 is not limited to the sliding contact rail 23 and the guide projection 24, but may also be a nesting type of sliding rail (not shown).

[0027] As shown in Figures 2 and 3, when the cassette extension 12 is positioned at the shortened position P3, the front-to-back dimension (total length) of the media cassette 10 is approximately the same as the front-to-back dimension (total length) of the cassette storage chamber 6 (or housing 2). Therefore, the entire media cassette 10 is almost entirely housed in the cassette storage chamber 6, and the front of the cassette extension 12 is approximately flush with the front of the housing 2 (see Figures 1 and 3). On the other hand, as shown in Figures 4 and 5, when the cassette extension 12 is positioned at the extended position P4, the total length of the media cassette 10 is longer than the total length of the cassette storage chamber 6 (or housing 2). Therefore, the front of the cassette extension 12 protrudes forward (outward) from the housing 2 (see Figure 5). The media cassette 10 with the cassette extension 12 positioned at the shortened position P3 houses the first media 9A, and the media cassette 10 with the cassette extension 12 positioned at the extended position P4 houses the second media 9B.

[0028] <Cassette cover> As shown in Figures 6 and 7, the cassette cover 13 has a flat cover body portion 26 and a pair of vertical cover plates 27 suspended from both sides of the cover body portion 26 in the left-right direction.

[0029] (Cover body) The cover body 26 is positioned along the top surface of the cassette storage chamber 6 (see Figure 7) and is provided to cover the top opening of the media cassette 10 (mainly the cassette extension 12). When viewed from above, the cover body 26 is formed in a roughly rectangular shape that covers the extension body 21 of the cassette extension 12 (see Figure 3). As shown in Figure 6, a cover-side base 30 is provided protruding from the rear end of the cover body 26, approximately in the center in the left-right direction. A housing-side base 31 is provided protruding from the top surface (housing 2) of the cassette storage chamber 6. The housing-side base 31 is positioned opposite the cover-side base 30 at a distance behind it (see also Figure 12, which will be described later).

[0030] As shown in Figure 7, both left and right ends of the cover body 26 are slidably inserted into cover guide grooves 32 recessed in a pair of left and right inner surfaces of the cassette storage chamber 6. At both left and right ends of the cover body 26, contact protrusions 33 are provided on the side end surface and bottom surface of the cover body 26, respectively, which contact the inner surface constituting the cover guide groove 32. The tips of the contact protrusions 33 are chamfered in an arc shape. The cassette cover 13 is supported so as to be slidable in the front-rear direction relative to the housing 2 by guiding both left and right ends of the cover body 26 into the cover guide grooves 32. In detail, the cassette cover 13 slides between a pushed-in position P5 (see Figures 2 to 4) where it is pushed into the housing 2 and positioned above the media cassette 10, and a protruding position P6 (see Figure 5) where it protrudes forward (outward) from the housing 2 and closes the upper surface of the cassette extension 12 positioned at extension position P4.

[0031] (Cover vertical plate) As shown in Figures 6 and 7, the pair of cover vertical plates 27 extend downward from positions offset inward from both ends of the cover body 26 in the left-right direction. The pair of cover vertical plates 27 are positioned between the left and right outer surfaces of the cassette body 11 and the left and right inner surfaces of the cassette storage chamber 6 (see also Figure 8, which will be described later). The pair of cover vertical plates 27 are positioned above the sliding rails 23 of the cassette extension 12 and are positioned approximately parallel to the left and right inner surfaces of the cassette storage chamber 6 with a gap in between. A locking projection 28 is provided on the outer surface (left surface) of the left cover vertical plate 27. The locking projection 28 is a rib formed to divide the cover vertical plate 27 approximately in half in the front-rear direction.

[0032] <Cover biasing member> As shown in Figures 6 and 7, the cover biasing member 14 is, for example, a compression coil spring, and is installed in a compressed state between the cover-side base 30 of the cassette cover 13 and the housing-side base 31 of the housing 2. The cover biasing member 14 biases the cassette cover 13 toward the protruding position P6 (forward). When the cassette cover 13 is biased by the cover biasing member 14 and moves to the protruding position P6, the cover-side base 30 abuts against the cover stopper 34 which protrudes from the top surface of the cassette storage chamber 6 (housing 2) (see also Figure 5). The cover biasing member 14 presses the cover-side base 30 against the cover stopper 34. This holds the cassette cover 13 in the protruding position P6 (see Figure 5).

[0033] <Cover lock section> As shown in Figures 8 and 9, the cover lock portion 15 is provided on the lower left side of the front of the housing 2 and is configured to lock the cassette cover 13. The cover lock portion 15 has a locking claw portion 40 and a locking biasing member 41.

[0034] (Lock claw part) The locking claw portion 40 has a shape in which a portion formed in a roughly rectangular parallelepiped shape is connected to the right side of a portion formed in a roughly triangular prism shape. The locking claw portion 40 has a locking inclined surface 40A, which is one surface on the protruding side (front) of the cassette cover 13, and a locking surface 40B, which is one surface on the pushing side (rear) of the cassette cover 13. As shown in Figure 9, the locking inclined surface 40A is one surface of the cassette cover 13 that is obliquely opposed to the cover vertical plate 27 and is inclined to the right from front to rear. The locking surface 40B is a plane that is bent relative to the locking inclined surface 40A and extends to the left, facing rear.

[0035] As shown in Figures 8 and 9, the locking claw portion 40 is housed in a locking chamber 35 formed in the lower left front part of the housing 2. The locking chamber 35 is a space with an opening on its right side (the side facing the cassette body 11). The rectangular parallelepiped portion of the locking claw portion 40 is supported in the locking chamber 35 in a state where it cannot be detached from the locking chamber 35 and can slide in the left-right direction. The locking claw portion 40 is provided with a triangular prism portion that can extend and retract from the opening of the locking chamber 35. In detail, the locking claw portion 40 slides between a locked position P11 (see Figures 8 and 9) in which it protrudes from the locking chamber 35 and locks the cassette cover 13 which is positioned in the pushed-in position P5, and an unlocked position P12 (see Figure 11, described later) in which it is housed in the locking chamber 35 and releases the locking of the cassette cover 13.

[0036] (Locking biasing member) As shown in Figures 8 and 9, the lock biasing member 41 is, for example, a compression coil spring, which is installed in a compressed state between the back surface of the lock inclined surface 40A of the lock claw portion 40 and the left inner surface of the lock housing chamber 35. The lock biasing member 41 biases the lock claw portion 40 toward the lock position P11. When the lock claw portion 40 is positioned at the lock position P11 and the cassette cover 13 is positioned at the push-in position P5, the locking projection 28 is locked to the lock locking surface 40B of the lock claw portion 40. This holds the cassette cover 13 in the pushed-in position P5.

[0037] <Unlock section> As shown in Figures 8 and 9 (and also Figure 10, which will be described later), the unlocking portion 16 is provided at the front end of the left wall portion of the cassette body 11 and is configured to engage with the cover lock portion 15. More specifically, the unlocking portion 16 is positioned between the cassette extension portion 12 and the cover lock portion 15 so as to be in contact with the sliding rail 23 and the lock claw portion 40. The unlocking portion 16 includes a release pressing portion 42 and a release biasing member 43.

[0038] (Release Pressing Part) The release pressing portion 42 is formed in a roughly triangular prism shape and has a release inclined surface 42A and a release straight surface 42B on the cassette extension portion 12 side (right side). As shown in Figure 9, the release inclined surface 42A is one surface that is diagonally opposite to the cassette body 11 and is inclined to the left from front to rear. The release straight surface 42B extends forward continuously from the release inclined surface 42A. The release inclined surface 42A is an inclined surface that is roughly parallel to the sliding inclined surface 23A of the sliding rail 23, and the release straight surface 42B is a plane that is roughly parallel to the sliding straight surface 23B of the sliding rail 23. In addition, a release recess 44 is formed as a recess on the front of the left side of the release pressing portion 42, and a release boss 45 protrudes from the rear of the left side of the release pressing portion 42.

[0039] The release pressing part 42 is housed in a release housing chamber 36 formed at the front end of the left wall of the cassette body 11. The release housing chamber 36 is a space with an opening at the rear of the left side (the side facing the locking claw part 40) and the entire right side. The release pressing part 42 is supported in the release housing chamber 36 in a state that allows it to slide in the left-right direction. The release pressing part 42 is provided so that it cannot be detached from the release housing chamber 36 by bringing the release inclined surface 42A or the release straight surface 42B, which is exposed from the right-side opening of the release housing chamber 36, into contact with the sliding rail 23. In addition, the release pressing part 42 is provided with a release boss 45 that can extend and retract from the left-side opening of the release housing chamber 36. In detail, the release pressing part 42 slides between a pressing position P21 (see Figure 10, described later) which presses the locking inclined surface 40A of the locking claw portion 40 located in the locked position P11 and slides the locking claw portion 40 to the unlocked position P12, and a non-pressing position P22 (see Figure 9) which releases the pressure on the locking inclined surface 40A of the locking claw portion 40.

[0040] (Release biasing member) As shown in Figure 9, the release biasing member 43 is, for example, a compression coil spring, which is installed in a compressed state between the abutment surface of the release recess 44 of the release pressing part 42 and the left inner surface of the release housing chamber 36. The release biasing member 43 biases the release pressing part 42 toward the non-pressed position P22. As will be described in detail later, when the cassette extension part 12 is positioned at the shortened position P3, the release pressing part 42 is held in the non-pressed position P22 by bringing the release inclined surface 42A into contact with the sliding inclined surface 23A of the sliding rail 23 (see Figure 9). When the cassette extension part 12 is positioned at the extended position P4, the release pressing part 42 is held in the pressed position P21 by bringing the release straight surface 42B into contact with the sliding straight surface 23B of the sliding rail 23 (see Figure 10, which will be described later). In other words, the left sliding rail 23 is formed so that the release pressing portion 42 can be pressed toward the pressing position P21 against the biasing force of the release biasing member 43.

[0041] [Operation of the cassette device] Next, the operation (function) of the cassette device 3 will be explained with reference to Figures 2 to 5 and Figures 10 to 13. Figure 10 is a plan view showing the state just before the lock on the cassette cover 13 is released. Figure 11 is a plan view showing the state after the lock on the cassette cover 13 has been released. Figure 12 is a side view (cross-sectional view) illustrating the movement of the cassette cover 13. Figure 13 is a plan view showing the process of returning the cassette cover 13 to the pushed-in position P5. Assuming that the initial state of the cassette device 3 is that the media 9 is not contained in the media cassette 10, the cassette body 11 is in the storage position P1, the cassette extension 12 is in the shortened position P3, and the cassette cover 13 is in the pushed-in position P5 (see Figure 3). Also, the locking claw 40 of the cover lock part 15 is in the locked position P11 and is engaged with the locking projection 28 of the cassette cover 13 (see Figures 8 and 9). Furthermore, the release pressing portion 42 of the lock release portion 16 is positioned in the non-pressed position P22, and the release inclined surface 42A of the release pressing portion 42 is in contact with the sliding inclined surface 23A of the sliding rail 23 (see Figure 9).

[0042] <When housing the first medium> Referring to Figures 2, 3, and 9, we will now describe the case in which the first medium 9A is placed in the media cassette 10 of the cassette device 3 in its initial state.

[0043] The user grasps the front of the cassette extension 12 and pulls the media cassette 10 forward. The cassette body 11 is moved from the storage position P1 to the pull-out position P2 (see Figure 2). The cassette extension 12, cassette cover 13, cover lock 15, and lock release 16 are maintained in their initial state. The user then places the first media 9A into the pulled-out media cassette 10 (cassette body 11 and cassette extension 12).

[0044] Next, the user pushes the media cassette 10 containing the first medium 9A into the cassette storage chamber 6 of the housing 2. The cassette body 11 moves from the pull-out position P2 to the storage position P1 (see Figure 3). During the process of the cassette body 11 moving to the storage position P1, the release press part 42 (release boss 45) located at the non-pressed position P22 does not interfere with the locking claw part 40 (see Figure 9). Therefore, the locking claw part 40 located at the locked position P11 engages with the locking projection 28 of the cassette cover 13, holding the cassette cover 13 in the pushed-in position P5 (see Figure 9). In other words, the state in which the media cassette 10 containing the first medium 9A is placed in the cassette storage chamber 6 is the same as the initial state.

[0045] As a result, the media cassette 10 containing the first medium 9A is placed inside the housing 2, and the image forming apparatus 1 becomes ready to form an image on the first medium 9A.

[0046] <When accommodating a second medium> Referring to Figures 2, 4, 5, and 10 to 12, we will now describe the case in which the second medium 9B is placed in the media cassette 10 of the cassette device 3 in its initial state.

[0047] The user pulls the media cassette 10 forward, moving the cassette body 11 from the storage position P1 to the pull-out position P2 (see Figure 2). Next, the user grasps the front of the cassette extension 12 and pulls the cassette extension 12 forward. The cassette extension 12 is positioned from the shortened position P3 to the extended position P4 (see Figure 4). As the cassette extension 12 moves to the extended position P4, the release pressing part 42 of the lock release part 16 is pushed to the left by the sliding rail 23 and moves relatively backward along the sliding inclined surface 23A and the sliding straight surface 23B (see Figures 4 and 10). The release pressing part 42 moves from a state where the release inclined surface 42A is in contact with the sliding inclined surface 23A to a state where the sliding straight surface 23B is in contact with the sliding straight surface 23B (see Figure 10). Furthermore, the release pressing part 42 is pushed to the left by the sliding rail 23 and moves from the non-pressed position P22 (see Figure 9) to the pressed position P21 (see Figure 10) against the biasing force of the release biasing member 43. The release pressing part 42 is pushed by the sliding rail 23 and embedded in the right-side opening of the release housing chamber 36, causing the release boss 45 to protrude from the left-side opening of the release housing chamber 36 (see Figure 10). The cassette cover 13 and the cover lock part 15 are maintained in their initial positions.

[0048] As shown in Figure 4, the media cassette 10 is extended in the front-to-back direction to accommodate the second media 9B. The user places the second media 9B into the media cassette 10.

[0049] Next, the user pushes the media cassette 10 containing the second media 9B into the cassette storage chamber 6 of the housing 2 (moving the cassette body 11 from the pull-out position P2 to the storage position P1 (see Figure 5)). As shown in Figure 10, during the process of pushing the cassette body 11 in (moving to the storage position P1), the release boss 45 of the release pressing part 42 located at the pressing position P21 contacts the locking inclined surface 40A of the locking claw part 40 located at the locking position P11. As shown in Figure 11, as the cassette body 11 is pushed in further, the release boss 45 moves backward along the locking inclined surface 40A while pushing the locking claw part 40 to the left. The locking claw part 40 is pushed to the left by the release boss 45 and moves from the locking position P11 (see Figure 10) to the unlocking position P12 (see Figure 11) against the biasing force of the locking biasing member 41. As the locking claw portion 40, positioned at the unlocked position P12, disengages from the locking projection 28 of the cassette cover 13, the cassette cover 13 moves from the pushed-in position P5 (see upper section of Figure 12) to the protruding position P6 (see middle section of Figure 12) under the biasing force of the cover biasing member 14. The cassette cover 13, positioned at the protruding position P6, abuts its tip (front end) against the front surface of the cassette extension portion 12, closing the upper opening of the cassette extension portion 12 that protrudes from the front of the housing 2 (see Figures 5 and middle section of Figure 12). With the cassette body 11 in the storage position P1, the release boss 45 continues to contact the locking inclined surface 40A of the locking claw portion 40, positioned at the unlocked position P12 (see Figure 11).

[0050] As a result, the media cassette 10 containing the second medium 9B is placed inside the housing 2, and the image forming apparatus 1 becomes ready to form an image on the second medium 9B.

[0051] <When changing from the second media to the first media> Referring to Figures 2 through 4, 9, 12, and 13, we will now describe the case in which the first medium 9A is stored in the media cassette 10 instead of the second medium 9B.

[0052] The user pulls the media cassette 10 forward, moving the cassette body 11 from the storage position P1 to the pull-out position P2 (see Figure 4). The release boss 45 of the release pressing part 42, located at the pressing position P21, moves forward from the locking inclined surface 40A of the locking claw part 40, and the locking claw part 40 is biased by the locking biasing member 41 to move from the unlocked position P12 to the locked position P11. The cassette cover 13 is held in the protruding position P6, and the front part of the cassette extension part 12 moves forward from the tip of the cassette cover 13. If the second media 9B remains in the media cassette 10, the user removes the second media 9B.

[0053] Next, the user pushes the cassette extension 12, which is positioned at extension position P4, backward to position it at shortened position P3 (see Figure 2). As the cassette extension 12 moves to shortened position P3, the release pressing part 42 of the unlocking part 16 moves relatively forward along the sliding contact linear surface 23B and the sliding contact inclined surface 23A. The release pressing part 42 is biased by the release biasing member 43 and moves from the pressed position P21 to the unpressed position P22, changing from a state where the release linear surface 42B is in contact with the sliding contact linear surface 23B to a state where the sliding contact inclined surface 23A is in contact with the sliding contact inclined surface 23A (see Figure 9). The release boss 45 is embedded in the left-side opening of the unlocking storage chamber 36.

[0054] As shown in Figure 2, the media cassette 10 is shortened in the front-to-back direction to accommodate the first medium 9A. The user places the first medium 9A into the media cassette 10.

[0055] Next, the user pushes the media cassette 10 containing the first media 9A into the cassette storage chamber 6 of the housing 2 (moving the cassette body 11 from the pull-out position P2 to the storage position P1 (see Figure 3)). As the cassette body 11 moves to the storage position P1, the front part of the cassette extension 12 abuts against the tip of the cassette cover 13 which is positioned at the protruding position P6 (see the middle section of Figure 12). The cassette body 11 is pushed in with the front part of the cassette extension 12 abutting against the tip of the cassette cover 13 (moving toward the storage position P1 (see the bottom section of Figure 12)). The cassette cover 13 moves together with the cassette body 11 as it moves from the pull-out position P2 to the storage position P1, from the protruding position P6 to the pushed-in position P5.

[0056] As shown in Figure 13, during the process of pushing the cassette cover 13 in (moving to the pushed-in position P5), the locking projection 28 of the cassette cover 13 contacts the locking inclined surface 40A of the locking claw portion 40 located at the locked position P11. As the cassette cover 13 is pushed in further, the locking projection 28 moves backward along the locking inclined surface 40A while pushing the locking claw portion 40 to the left. Once the locking projection 28 overcomes the locking inclined surface 40A, the locking claw portion 40 is biased by the locking biasing member 41 and moves to the locked position P11 (see Figure 9). The locking projection 28 is locked to the locking surface 40B, and the cassette cover 13 is held in the pushed-in position P5 (see Figure 9). Also, the release pressing portion 42 located at the non-pressed position P22 does not interfere with the locking claw portion 40, and the cassette body 11 is positioned at the storage position P1 (see Figure 9).

[0057] As a result, the media cassette 10 containing the first medium 9A is placed inside the housing 2, and the image forming apparatus 1 becomes ready to form an image on the first medium 9A.

[0058] In the cassette device 3 according to the embodiment described above, when the cassette extension 12 is positioned in the shortened position P3, the unlocking unit 16 does not engage with the cover locking unit 15 during the process of sliding the cassette body 11 from the pull-out position P2 to the storage position P1, and the cover locking unit 15 locks the cassette cover 13 and holds it in the pushed-in position P5 against the biasing force of the cover biasing member 14. Furthermore, when the cassette extension 12 is positioned in the extended position P4, the unlocking unit 16 engages with the cover locking unit 15 during the process of sliding the cassette body 11 from the pull-out position P2 to the storage position P1, releasing the locking of the cassette cover 13 by the cover locking unit 15, and the cassette cover 13 is biased by the cover biasing member 14 and slides from the pushed-in position P5 to the protruding position P6. With this configuration, when a first medium 9A such as A4 size is placed in the shortened media cassette 10, the cassette cover 13 can be held in the pushed-in position P5, and when a second medium 9B such as legal size is placed in the extended media cassette 10, the cassette cover 13 can be automatically placed in the protruding position P6. As a result, the top opening of the cassette extension 12 that extends outward from the housing 2 can be automatically covered with the cassette cover 13. Consequently, it is prevented from the user touching the medium 9 inside the cassette extension 12 (media cassette 10) during printing, or from foreign matter such as dust entering the media cassette 10.

[0059] Furthermore, in the cassette device 3 according to this embodiment, when the cassette extension 12 is positioned in the shortened position P3, the release pressing part 42 is not pressed by the sliding rail 23, but is biased by the release biasing member 43 and slides from the pressed position P21 to the unpressed position P22, and does not press the locking claw part 40 during the process of sliding the cassette body 11 from the pull-out position P2 to the storage position P1, and the locking surface 40B of the locking claw part 40 engages the locking projection 28 to hold the cassette cover 13 in the pushed-in position P5. Furthermore, with the cassette extension 12 positioned at extension position P4, the release pressing portion 42 is pressed against the sliding rail 23 and slides from the unpressed position P22 to the pressed position P21 against the biasing force of the release biasing member 43, pressing the lock inclined surface 40A in the process of sliding the cassette body 11 from the pull-out position P2 to the storage position P1, causing the lock claw portion 40 to slide from the locked position P11 to the unlocked position P12 against the biasing force of the lock biasing member 41, and the cassette cover 13 is biased by the cover biasing member 14 and positioned at the protruding position P6. Furthermore, when the cassette extension 12 is positioned in the shortened position P3 and the cassette cover 13 is positioned in the protruding position P6, the cassette cover 13 is pushed by the cassette body 11, which slides from the pull-out position P2 to the storage position P1, and slides from the protruding position P6 to the pushed-in position P5. The locking projection 28 slides on the locking inclined surface 40A, causing the locking claw portion 40 to slide to the unlock position P12, overcoming the locking inclined surface 40A and locking onto the locking surface 40B. With this configuration, the release pressing portion 42 and the locking claw portion 40 can be slid by utilizing the force that slides the cassette extension 12 (sliding rail 23) and the cassette body 11, without using a power source such as an electric motor. In addition, by positioning the cassette extension 12 in the shortened position P3 or the extended position P4 according to the size of the media 9 and returning the cassette body 11 (media cassette 10) to the storage position P1, the cassette cover 13 can be automatically moved to the appropriate position.

[0060] In the cassette device 3 according to this embodiment, the position where the entire cassette body 11 is pulled out from the housing 2 (cassette storage chamber 6) is defined as the pull-out position P2, but the present invention is not limited to this. For example, when the cassette body 11 is positioned at the pull-out position P2, the front half of the cassette body 11 may be pulled out from the housing 2 (cassette storage chamber 6), and the rear half of the cassette body 11 may be housed inside the housing 2 (cassette storage chamber 6) (not shown).

[0061] Furthermore, in the cassette device 3 according to this embodiment, the release pressing portion 42 was formed in a substantially triangular prism shape, but the present invention is not limited thereto. In other examples, the release pressing portion may be formed in a rod shape with a rounded tip that contacts the sliding rail 23, or it may be equipped with a roller that rotates while in contact with the sliding rail 23 (neither of which are shown). In addition, a roller that rotates while in contact with the locking inclined surface 40A of the locking claw portion 40 may be provided at the tip of the release boss 45 of the release pressing portion 42 (not shown).

[0062] Furthermore, in the cassette device 3 according to this embodiment, the locking claw portion 40 and the release pressing portion 42 are arranged side by side in the left-right direction and are slidable in the left-right direction, but the present invention is not limited thereto. For example, the locking claw portion 40 and the release pressing portion 42 may be arranged side by side in the up-down direction and be slidable in the up-down direction (not shown). In that case, the position and shape of the sliding contact rail 23 of the cassette extension portion 12 may be appropriately changed to match the release pressing portion 42 (not shown).

[0063] Furthermore, in the description of the above embodiment, the image forming apparatus 1 was a printer that forms images using an electrophotographic method, but it is not limited to this, and may be a printer that forms images using an inkjet method, for example (not shown). Also, the image forming apparatus 1 is not limited to a printer, but may be a facsimile machine, a copier, or the like.

[0064] The above description of embodiments illustrates one aspect of the cassette device and image forming apparatus according to the present invention, and the technical scope of the present invention is not limited to the above embodiments. The present invention may be modified, substituted, or transformed in various ways without departing from the spirit of the technical idea, and the claims include all embodiments that may fall within the scope of the technical idea. [Explanation of Symbols]

[0065] 1. Image forming apparatus 2 cabinets 4. Imaging device 9 Medium 10 media cassettes 11 Cassette Unit 12 Cassette extension 13 Cassette Covers 14 Cover biasing member 15 Cover lock section 16. Unlocking section 23 Sliding rail 28 Locking protrusion 40 Locking claw section 40A Rock Inclined Surface 40B Locking surface 41 Lock biasing member 42 Release Pressing Part 43 Release biasing member P1 Accommodation location P2 drawer position P3 Shortened position P4 extended position P5 Push position P6 protruding position P11 Lock position P12 Unlock Location P21 Pressing position P22 Non-pressed position

Claims

1. A cassette body that slides between a housing position where it is housed in the housing of the image forming apparatus and a pull-out position where it is pulled out from the housing to the outside, A cassette extension is provided on the leading end side of the cassette body in the pull-out direction, and together with the cassette body, constitutes a media cassette that houses the media, and slides between a shortened position that fits inside the cassette body to form a shortened media cassette and an extended position that forms a media cassette that extends in the pull-out direction. A cassette cover slides between a pushed-in position, where it is pushed into the housing and positioned above the media cassette, and a protruding position, where it protrudes outward from the housing and closes the upper surface of the cassette extension, which is positioned at the extension position. A cover biasing member that biases the cassette cover toward the protruding position, The housing is provided with a cover locking portion capable of securing the cassette cover, The cassette body is provided with a lock release part that can engage with the cover lock part, When the cassette extension is positioned in the shortened position, the unlocking portion does not engage with the cover lock portion during the process of sliding the cassette body from the pull-out position to the storage position, and the cover lock portion locks the cassette cover and holds it in the pushed-in position against the biasing force of the cover biasing member. A cassette device characterized in that, when the cassette extension is positioned in the extension position, the unlocking part engages with the cover locking part during the process of sliding the cassette body from the pull-out position to the storage position, thereby releasing the locking of the cassette cover by the cover locking part, and the cassette cover slides from the push-in position to the protruding position, biased by the cover biasing member.

2. The aforementioned cover locking portion is A locking claw slides between a locking position that engages the cassette cover positioned in the aforementioned push-in position and an unlocking position that releases the locking of the cassette cover, The locking biasing member comprises a locking claw portion that biases the locking claw portion toward the locked position, The aforementioned locking claw portion is The aforementioned cassette cover has a locking inclined surface which is one of the protruding sides, The cassette cover has a locking surface which is one side of the push-in side, The cassette cover has a locking projection that engages with the locking surface of the locking claw portion, which is positioned in the locked position when the cassette cover is in the pushed-in position. The aforementioned unlocking unit is A release pressing part slides between a pressing position that presses the locking inclined surface of the locking claw portion positioned in the locked position to slide the locking claw portion to the unlocked position, and a non-pressing position that releases the pressure on the locking inclined surface of the locking claw portion. The release biasing member biases the release pressing portion toward the non-pressed position, The cassette extension has a sliding rail that can press the release pressing portion toward the pressing position, When the cassette extension is positioned in the shortened position, the release pressing portion is not pressed by the sliding rail, but is biased by the release biasing member and slides from the pressed position to the unpressed position, and does not press the locking claw portion during the process of sliding the cassette body from the pull-out position to the storage position, and the locking surface of the locking claw portion engages the locking projection to hold the cassette cover in the pushed-in position. With the cassette extension positioned in the extension position, the release pressing portion is pressed against the sliding rail and slides from the unpressed position to the pressed position against the biasing force of the release biasing member, pressing against the lock inclined surface in the process of sliding the cassette body from the pull-out position to the storage position, causing the lock claw portion to slide from the locked position to the unlocked position against the biasing force of the lock biasing member, and the cassette cover is positioned in the protruding position, biased by the cover biasing member. The cassette device according to claim 1, characterized in that, when the cassette extension is positioned in the shortened position and the cassette cover is positioned in the protruding position, the cassette cover slides from the protruding position to the pushed-in position by being pushed by the cassette body which slides from the pull-out position to the storage position, the locking projection slides on the locking inclined surface, causing the locking claw to slide to the unlock position, overcomes the locking inclined surface, and is locked to the locking surface.

3. A cassette device according to claim 1 or 2, An image forming apparatus characterized by comprising an image forming apparatus that forms an image on the medium fed out from the medium cassette.

Images