Image forming apparatus

Abstract: An image forming apparatus comprises a body perfor­ ming an image forming operation; and a receiving device provided on the rear part of the body for receiving a pa­ per feeding member (7), the receiving device comprising a guide member (20) which supports the paper feeding member (7) while shifting between a first position where the pa­ per feeding member (7) is brought into a sharply inclined state, and a second position where the paper feeding mem­ ber is kept in a fallen state. Since the guide member which is designed to be shifted in response to insertion, attachment and removal of the paper feeding member (7) is provided, the promoting force is added so that such opera­ tions are more smoothly performed.

Description: The present invention relates to an image forming apparatus as defined in the preamble of the claim 1. An image forming apparatus of that kind is known from US-A-3 877 809. The said apparatus comprises a body performing an image forming operation and a receiving device provided on a side part of said body for receiving a paper feeding member. The said receiving member includes a guide member which supports said paper feeding member in such a manner that it may be rotated between a first position where said paper feeding member is held in a sharply inclined state and a second position where it is kept in a fallen state. With the said structure, in order to reduce the size of the body as much as possible, it is necessary to excessively bend the paper conveying path which makes it difficult to achieve smooth paper feeding. Further, EP-A-0 121 908 discloses a similar apparatus using spring means to bias a paper support plate in an upward direction. For attachment and detachment said paper support plate has to be brought into a substantially horizontal state such that a fairly large space is required in the periphery of the body of the said apparatus for the said actionss. It is an object of the present invention to provide an image forming apparatus which is constructed in such a manner that on its operation side where the operation panel is installed a table or cassette for feeding paper may be inserted, attached and removed easily. The said object according to the present invention is achieved by a structure as defined in the claim 1. Advantageous further developments of the present invention are defined in the dependent claims. According to the present invention for attaching and detaching the paper feeding member is located at a position where it is brought into a sharply inclined state and for setting the paper feeding member to a paper feeding position it is located at a position where it is lowered to a fallen state from said sharply inclined state. As the paper feeding member shifts from said first position to said second position it is moved toward an inner part of the body of the apparatus. Moreover, the operations of insertion of the paper feeding member into the back side of the body, atttachment thereto and removal therefrom may be performed easily, since it is possible to perform it from the operation side. For further explaining the features and advantages of the present invention reference is now made to the accompanying drawings in which Fig. 1 is a schematic side view of a conventional image forming apparatus; Fig. 2 is a schematic side view of another conventional image forming apparatus; Fig. 3 is a schematic sectional side view of an image forming apparatus partially modified from that as shown in Fig. 2; Fig. 4 is a partially cutaway perspective view of an essential portion of an image forming apparatus according to the present invention; and Fig. 5 is an exploded side view showing a part of the construction of the image forming apparatus of Fig. 4; and Figs. 6 (a) and 6(b) are views showing the receiving device for attaching the paper feeding member in the image forming apparatus of Fig. 4. As shown in Fig. 1, conventionally, some image forming apparatuses (i.e., electronic copying machines or printers, etc.) generally include such a structure that a paper feed cassette 3 and a by-path table 4 are attached on the opposite side (B) (hereinafter, referred to as "back side") to the operation side (A) where an operation panel 2 of a body 1 which performs the image forming operation is provided. Further, as shown in Fig. 2, it has been proposed that another cassette, i.e., a feeder cassette 7 is attached on the back side (B) via a feeder 6 in addition to a paper feed cassette 5 to be inserted from the operation side (A). And, there has also been proposed such an apparatus (not illustrated) that the feeder cassette 7 is attached directly on the body 1, not through the feeder 6. For easier understanding, Fig. 3 schematically shows the construction of the image forming apparatus of the type as shown in Fig. 2. In Fig. 3, the shape of the feeder 6 is somewhat modified from that in Fig. 2 so that the feeder cassette 7 may be obliquely attached in consideration of the operating efficiency. In Fig. 3, Numeral 8 indicates paper feed rollers which guide a paper 9 from the paper feed cassette 5 onto a reversing transport path 10, and Numerals 11, 12, 13 and 14 indicate resist rollers, a printer drum, fix rollers and a discharge tray, respectively. Meanwhile, on the feeder 6 side are provided paper feed rollers 16 by which a paper 15 in the feeder cassette 7 attached to the feeder 6 is guided onto a transport path 17 toward the resist rollers 11. Numeral 18 indicates a spring which raises the front end portion of the paper 15 toward the paper feed roller 16 side. The by-path table 4 in Fig. 1 and the feeder cassette 7 in Fig. 3 are inserted at a sharp inclination relative to the body 1 and the feeder 6 respectively so that the operation may be performed with facility and each paper may be without fail brought in contact with the paper feed rollers. Thereafter, the by-path table 4 and the feeder cassette 7 are brought down to be positioned in the attached state as shown in Fig. 1 and Fig. 3 respectively, and they are brought from the attached state as shown in Fig. 1 and Fig. 3 into the sharply inclined state again when they are removed. According to the above-described constructions of the conventional image forming apparatuses, in order to insert the by-path table 4 or the feeder cassette 7 into the body 1 or the feeder 6 respectively and remove therefrom, an operator has to take the trouble to turn from the operation side (A) to the back side (B) of the apparatus, which gives the operator not a little inconvenience. Additionally, it is wholly left to the operation along a stationary guide member by the operator that the by-path table 4 or the feeder cassette 7 is inserted from the sharply inclined position, brought down into the attached state and lifted again to be removed, therefore it may be said that some practice is required for such operation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be explained with reference to the drawings. Fig. 4 shows application of the present invention to the image forming apparatus of the type as shown in Fig. 3. In Fig. 4, a stationary first guide member 19 which guides the upper side of the feeder cassette 7 is provided in the vicinity of each end of a shaft of the paper feed rollers 16 on each inner surface of side plates (i. e. , stationary support plates) 6a and 6b of the feeder 6. In addition, on each side plate is provided a slidable second guide member 20 which guides the underside of the feeder cassette 7 as opposing to the first guide member 19. Hereinafter, explanation will be made only on the second guide member 20 mounted on the side plate 6a. A L-shaped portion 22, a pin support portion 23 and a port ion 24 having a slide slot 25 constitute the second guide member 20, which is, as shown in Fig. 5, mounted on the side plate 6a in the following manner: A screw portion 27a of a first pin 27 is screwed into a tapped hole 28 of the pin support portion 23 from the outside of the side plate 6a through a guide slot 26 formed thereon as sandwiching the side plate 6a. At this time, a slide portion 27b of the first pin 27 is slidably fit in the guide slot 26. Thus, a first slide mechanism is constituted with the first pin 27 screwed into the tapped hole 28 of the pin support portion 23, and the guide slot 26. On the other hand, a screw portion 29a of a second pin 29 is screwed into a tapped hole 60 of the side plate 6a through the slide slot 25 as sandwiching the portion 24 having the slide slot 25, and the slide slot 25 is slided relative to a slide portion 29b of the second pin 29. Thus, a second slide mechanism is constituted with the above-mentioned portion 24 and the second pin 29. The first pin 27 is, as shown in Fig. 6 (a), given obliquely upward biasing force by a spring member 30, therefore when the feeder cassette 7 is not inserted, the second guide member 20 is slided to the top end of the guide slot 26 and brought in the raised state. The guide slot 26 is bow shaped, drawing an arc from the top end to the bottom , while the slide slot 25 takes shape of a bow or a straight line. Next, the action of the second guide member 20 will be explained with reference to Figs. 6 (a) and 6 (b). When the feeder cassette 7 is not inserted, the second guide member 20 remains lifted up due to the spring member 30 as shown in Fig. 6 (a). Accordingly, in this state, insertion of the feeder cassette 7 is performed from substantially just above. The insertion brings one end portion of the feeder cassette 7 in contact with the base of the L-shaped portion 22, resulting in that the second guide member 20 is shifted downward against the upward biasing force of the spring member 30 because of the weight of the feeder cassette 7. At this time, the slide portion 27b of the first pin 27 secured to the second guide member 20 is slided downward along the guide slot 26 of the side plate 6a. Simultaneously, the slide slot 25 of the second guide member 20 is slided downward while contacting to the slide portion 29b of the second pin 29 which is fixed to the side plate 6a through the second guide member 20. As a result, the second guide member 20 falls into the state as shown in Fig. 6 (b), and in this state, attachment of the feeder cassette 7 is completed. At this position, the upper front end of the feeder cassette 7 is brought into contact with the first guide member 19, therefore the feeder cassette 7 remains in the stopped state against such force as to rotate in the counterclockwise direction relative to the first pin 27 due to its weight. Next, when the feeder cassette 7 in the state as shown in Fig. 6(b) is removed from the feeder 6, the second guide member 20 is shifted upwardly in response to the upward force which is added at the time of the removal of the feeder cassette 7. In this case, the spring member 30 actuates so as to facilitate the upward motion of the second guide member 20. The feeder cassette 7 is thus smoothly brought to the position as shown in Fig. 6 (a) to be easily removed. As described above, the second guide member 20 shifts between the positions as shown in Figs. 6 (a) and 6 (b) in response to the insertion, attachment and removal of the feeder cassette 7, therefore in such displacement actions of the second guide member 20, the promoting force is designed to be added for facilitating the smooth insertion, attachment and removal operations. Consequently, the feeder cassette 7 can be conveniently inserted into and removed from the back side of the image forming apparatus by the operation on the operation side. In the above-described embodiment, only the case of attaching the feeder cassette 7 is explained, however, not limited thereto, the above construction is similarly applicable in the case of the by-pass table or other paper feed cassettes. Additionally, though the movable second guide member 20 and the spring member 30 and so on are adopted as auxiliary means in the present embodiment, another mechanism may be utilized in place of them. Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be noted here that various changes and modifications will be apparent to those skilled in the art.

Claims: An image forming apparatus comprising a body (1) performing an image forming operation and a receiving device provided on the rear part of said body for receiving a paper feeding member (7) and comprising guide members (19, 20) supporting said paper feeding member while shifting between a first position where said paper feeding member is brought into a sharply inclined state and a second position where said paper feeding member is kept in a fallen state, characterised in that said receiving device further comprises stationary supporting side plates (6a, 6b) having bowed guide slots (26) formed therein, that each side plate (6a, 6b) is provided with a slidable guide member (20) supporting the underside of said paper feeding member (7), that each guide member (20) includes a pin support portion (23), a slot portion (24) having a slide slot (25) formed therein and an L-shaped portion (22) for supporting said paper feeding member (7), that each guide member (20) has a pin (27) fixed to its pin support portion (23) for slidably extending into said bowed guide slot (26) in said side plate (6a, 6b), that each side place (6a, 6b) has a pin (29) fixed thereto for slidably extending into said slide slot (25) in said guide member (20) and that biasing means (30) are provided for biasing said guide members (20) toward said first position. An apparatus according to claim 1 , characterised in that said biasing means are spring means (30) exerting force on said guide member (20) to hold said first position and shift against said force when brought to said second position due to weight of said paper feeding member (7). An apparatus according to claim 2, characterised in that each spring means (30) is fixed at each end to said side plates (6a, 6b) and said pins (27) respectively. An apparatus according to claim 1, characerised in that said paper feeding member (7) is a paper feed cassette. An apparatus according to claim 1, characterised in that said paper feeding member (7) is a paper feed tray. An apparatus according to claim 1, characterised in that said body (1) is an electronic copying machine. An apparatus according to claim 1, characterised in that saiud body (1) is a printer. An apparatus according to claim 1, characterised in that the rear part of said body (1) is a paper feeder. An apparatus according to claim 1, characterised in that said receiving device further comprises stationary guide members (19) provided as opposing said movable guide members (20).

Inventors: SASABE JUNYA, SUGIMORI MASAO, SASABE, JUNYA, SUGIMORI, MASAO
Applicants: MITA INDUSTRIAL CO LTD, MITA INDUSTRIAL CO. LTD.
Application year: 1989
Main classification: G03G15
IPC codes: B65H1, G03G15