JP3415940B2 - Printer paper feeder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper supply device for a printer. 2. Description of the Related Art In a paper feeder of a printer for feeding cut sheets, when the paper is placed on a feed plate (also called a table or a hopper) located at a rear portion of the printer, the paper is fed. The sheet is conveyed to the print head one by one by contacting the feed roller located at the end of the plate and rotating the feed roller. However, the feed roller may take out two sheets in an overlapping state, and it is desirable to prevent such two sheets from being conveyed as they are in an overlapped state (double feeding of sheets). For this reason, a friction plate called a pressure plate or a friction separator is disposed immediately adjacent to or in contact with the feed roller at a position immediately downstream of the feed plate, and prevents double feeding of paper by utilizing friction. It has been implemented. In this case, when two sheets are fed between the feed roller and the pressure plate in an overlapping state, one sheet in contact with the feed roller is transported by the feed roller, and the other sheet is pressed by the pressure plate. , And stop by the friction between them, and are prevented from proceeding further, so that double feeding of paper is prevented. For example, Japanese Patent Application Laid-Open No. 63-242844 discloses a friction separator which is positioned to sandwich a sheet supplied from a hopper (feed plate) with a feed roller in order to prevent double feeding of sheets. It is disclosed that. The mounting angle of this friction separator is variable. The reason why the mounting angle of the friction separator is made variable is to accommodate paper having different thicknesses and rigidities. Japanese Patent Application Laid-Open No. 61-221223 discloses the provision of a friction pad which is close to or in contact with a feed roller in order to prevent double feeding of sheets. In this publication, a paper feed table (feed plate) is configured to be able to move up and down by a rack and a pinion mechanism. The feed roller moves up and down following the elevation of the sheet feeding table, and the friction pad moves up and down according to the elevation of the feed roller. As a result, the position of the friction pad changes, so that when the thickness of the sheet changes, the position of the friction pad can be changed to prevent paper feeding errors and double feeding. [0006] In such a paper supply apparatus for a printer, there is a problem in which a paper feed error or a double feed of paper occurs depending on the thickness and flexibility of the paper or the strength of the waist. Because of the difference, it is required to make the positions of the feed plate and the pressure plate variable. However, as disclosed in the first publication, when the angle of the friction separator is made variable, the traveling direction of the paper passing between the friction separator and the feed roller changes, and another feeder located ahead of the friction separator is changed. It may not be pinched properly by the rollers. In addition, when there is a guide for assisting the running of the paper at the end of the friction separator, it is necessary to change the position of the guide according to the friction separator. As described in the above-mentioned second publication, the position of the friction pad is changed by raising and lowering the sheet feeding table, moving the feed roller up and down, and further moving the friction pad up and down. Then, since these three members move up and down in combination with each other, the mutual positional relationship between these three members does not substantially change. In addition, since a configuration in which a rack and a pinion mechanism are mounted on the paper feed table is required, there is a problem that the size of the paper supply device increases. SUMMARY OF THE INVENTION An object of the present invention is to provide a paper feeding apparatus for a printer which can prevent paper feeding errors and double feeding according to the type of paper used, and can reliably feed paper. That is. According to the present invention, there is provided a paper supply apparatus for a printer, comprising a feed roller, a paper sheet disposed close to or in contact with the feed roller, and a paper sheet passing between the feed roller. And a feed plate 16 for supplying paper between the feed roller and the pressure plate, and one end of the feed plate. Is urged toward the feed roller by a spring, and a support shaft 28 provided at the other end of the feed plate is inserted into an elongated hole 30 provided in a housing of the apparatus and is movable along the elongated hole. A lever 32 for setting the angular position of the feed plate, so that the feed plate is substantially rotatable about the one end.
Is provided. In the above configuration, the feed plate is rotatable substantially around one end on the feed roller side, and the angle between the pressure plate and the feed plate can be reliably changed. Therefore, for example, when relatively thick paper is used, the angle between the pressure plate and the feed plate is increased, and when relatively thin paper is used, the angle between the pressure plate and the feed plate is increased. , The feeding error and the double feeding can be prevented for thick and thin paper. FIG. 1 is a cross-sectional view of a main part of the paper supply apparatus of FIG. 2, and FIG. 2 is a perspective view showing a paper supply apparatus 10 utilizing the present invention. FIG. 3 is a sectional view taken along line III--III in FIG.
FIG. 4 is a partial plan view of FIG. 3. FIGS. 5 and 6 show a state where the printer 50 is combined with the paper supply apparatus 10. The paper supply device is the outer housing 12
A member for supplying paper to the print head of the printer 50 is provided in the outer housing 12. As shown in FIG. 2, the paper supply device 10
Has an inclined housing 12a which is a part of the outer housing 12, which has a box-like shape with one open side, and has side walls 12b, 12c and a rear wall 1.
2d. There are top walls 12e, 12f that protrude inward from the tops of the side walls 12b, 12c. As shown in FIGS. 1 and 2, a feed plate 16 is disposed along the inner surface of the rear wall 12d. The feed roller 1 is provided inside the outer housing 12.
8 and a pressure plate 20 are arranged. The pressure plate 20 is disposed close to the feed roller 18 and has a rubber material 20a adhered to a surface facing the feed roller 18, and the rubber material 20a provides a desired friction.
The pressure plate 20 is urged toward the feed roller 18 by a spring 22, and contacts the feed roller 18 when there is no sheet between them. The feed plate 16 is disposed obliquely,
One end 16 a of the feed plate 16 is urged toward the feed roller 18 by a spring 24. Paper 2
6 can be placed as a bundle on the feed plate 16, and the paper 26 enters between the one end 16 a of the feed plate 16 and the feed roller 18 and comes into contact with the pressure plate 20. A support shaft 28 extending horizontally is integrally provided at the other end 16b of the feed plate 16. On the other hand, the side walls 12b and 12c of the housing 12a have elongated holes 3
0 is provided. The elongated hole 30 is provided near the horizontal and with an inclination corresponding to the inclination of the inclined housing 12a. The support shaft 28 is inserted into the elongated hole 30 and is movable along the elongated hole 30. In this case, one end 16 of the feed plate 16
Since a is biased toward the feed roller 18 by the spring 24, the position of the same end 16a is substantially fixed, so that the feed plate 16 is substantially rotatable about the one end 16a. It is. Accordingly, the angle θ between the pressure plate 20 and the feed plate 16 is variable. further,
An angle setting lever 32 is provided on the top walls 12e and 12f of the housing 12a. As shown in FIGS. 1 and 3, the lever 32 is slidable in the direction in which the elongated hole 30 extends along the top walls 12e and 12f, and a part of the sliding surface has a saw-tooth shape. An engagement surface 34 is provided. The lever 32 has a knob 32a, and the lever 32 can be operated by a human hand. Lever 32
(Therefore, the other end 16b of the feed plate 16) is stopped at a position corresponding to each tooth of the sawtooth. The lever 32 has an integrally formed spring-like tongue 36 which is formed on the top walls 12e, 12f.
Resiliently engage the lower surface of the top wall 12e,
It is urged in the direction of contact with 12f. The fork leg 38 of the lever 32 extends through the opening in the top walls 12e, 12f into the housing 12a and
Of the support shaft 28 is sandwiched. Therefore, when the lever 32 is moved, the feed plate 16 rotates,
The zero and fork-shaped legs 38 absorb the extra movement and allow the feed plate 16 to rotate substantially about one end 16a. As shown in FIG. 4, the housing 12a
Scales 40 are formed on the top walls 12e and 12f in parallel with the lever 32. On the scale 40, reference characters such as postcards corresponding to thick paper, plain paper, and Japanese paper corresponding to thin paper are written. In the embodiment, when the lever 32 is moved in the direction of the postcard, the feed plate 16 is moved.
Moves in the direction in which the angle θ increases, and conversely, when the lever 32 is moved in the direction of Japanese paper, the feed plate 16 moves in the direction in which the angle θ decreases. In the case of thick paper, double feeding of the paper is relatively unlikely to occur, but a relatively large feeding force is required. When the angle θ is small, the feed force needs to be relatively large, but when the angle θ is large, the feed force may be relatively small. Therefore, in the case of a thick sheet, the sheet can be reliably supplied without applying an excessive feeding force by moving the feed plate 16 in the direction in which the angle θ increases. Further, in the case of thin paper, the double feed of the paper is relatively easy to occur, and the double feed of the paper is more likely to occur as the angle θ is larger. Accordingly, in the case of a thin sheet, the feed plate 16 is moved in the direction in which the angle θ becomes smaller, so that the double feed of the sheet can be reliably prevented. As described above, according to the present invention,
Paper feeding errors and double feeding can be prevented according to the type of paper used from thick to thin paper, and paper can be supplied reliably.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a main part of the present invention, showing a part of the paper supply device of FIG. FIG. 2 is a perspective view showing a sheet supply device according to the embodiment of the present invention. FIG. 3 is a sectional view taken along line III-III in FIG. 2; FIG. 4 is a partial plan view of FIG. 3; FIG. 5 is a perspective view showing a state where the printer is combined with the paper supply device of FIG. 2; FIG. 6 is a perspective view showing a state where the printer is combined with a paper supply device. [Description of Signs] 12, 12a ... Housing 16 ... Feed plate 18 ... Feed roller 20 ... Pressure plate 28 ... Support shaft 30 ... Slot 32 ... Lever

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-18233 (JP, A) JP-A-4-235835 (JP, A) JP-A-63-185743 (JP, A) JP-A-55-185 84730 (JP, A) JP-A-7-330183 (JP, A) JP-A-61-221023 (JP, A) JP-A-63-242844 (JP, A) Japanese Utility Model Laid-Open No. 63-41035 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B65H 1/02 B41J 13/00

Claims (1)

(57) [Claim 1] A feed roller (18) is disposed close to or in contact with the feed roller, and applies friction to a sheet passing between the feed roller and the feed roller. A pressure plate (20) for preventing double feeding of sheets, and a feed plate (16) for feeding sheets between the feed roller and the pressure plate, one end of the feed plate being a spring. , The support shaft (28) provided at the other end of the feed plate is inserted into an elongated hole (30) provided in the housing of the apparatus, and is movable along the elongated hole. And
Accordingly, the feed plate is rotatable substantially around the one end, and a lever (32) for setting an angular position of the feed plate is provided.