JP2856040B2 - Paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder such as a color printer having a paper return operation for sequentially printing a plurality of colors.

[0002]

2. Description of the Related Art Generally, a color printer of this type is shown in FIG. FIG. 7 is a side view in which a part of a thermal transfer type color printer is cut away. In the figure,
Reference numeral 1 denotes a box-shaped paper feeding case, and a hopper 3 on which photographic paper 4 is placed is urged upward by a compression spring 2 interposed on the bottom surface. Reference numeral 5 denotes a pair of separation claws provided at both ends of the front portion of the paper feeding case. Reference numeral 6 denotes a paper feed roller serving as a paper driving force adding unit.
The roller arm 7 is pivotally supported by the roller arm 7 and swings in the direction A to abut on the photographic printing paper 4 and is rotated clockwise in the drawing. 11 is a conveyance guide for forming a paper feed path 11a, 12 is an ink ribbon,
13 is a thermal head, 14 is a platen roller in contact with the thermal head, and 15 is a pair of paper feed rollers driven by a motor 16.

In such a configuration, when the sheet feeding operation is started, the roller arm 7 is driven to swing in the direction A, the sheet feeding roller 6 comes into contact with the printing paper, and the hopper 3 is urged upward. The photographic paper 4 is pressed against the paper feed roller 6, and the rotation of the paper feed roller 6 causes the photographic paper 4 to be conveyed to the transport guide 1.
It is pushed out to one side. Only one photographic paper 4 is taken out of the paper feed case 1 by the separation claw 5. The photographic paper 4 is the transport guide 1
When the roller arm 7 is guided by 1 and reaches the paper feed roller 15, the roller arm 7 swings in the B direction, and the paper feed roller 6 is retracted upward.
When the printing paper 4 is nipped by the paper feed roller 15, the platen roller 14 comes into contact with the thermal head 13 to start printing, and the printing paper 4 is transported in the E direction by the forward rotation of the motor 16. When the printing of the first color is completed, the platen roller 14 is separated from the thermal head 13, and the photographic paper 4 is conveyed in the F direction by the reverse rotation of the motor 16 to return the photographic paper 4 to the printing start position. Then, the printing paper 4 is transported again in the direction E, and printing of the second color is performed by the ink ribbon 12 of another color.

[0004]

As described above, a color printer requires a paper return operation in order to perform overprinting. The rear end of the photographic paper 4 when returning the paper is a paper guide 1
Just by imitating 1, you will be free. For this reason, the rear end of the photographic paper 4 abuts on the separation claw 5 in the paper feed case 1,
Due to the static electricity, the paper 4 is attracted to the photographic paper 4 stored in the paper feed case 1 and causes a paper jam.

Accordingly, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a paper feeder in which paper jam is prevented.

[0006]

In order to achieve this object, a paper feeding apparatus according to the present invention comprises a paper driving force applying means which can freely contact and separate paper stored in a paper feeding case. In a paper feeder for feeding paper sheets one by one to a paper feed path, the normal paper feed path is shut off, and the paper drive A reverse feed preventing member for opening a paper path is provided. When the paper is fed backward after the first printing , the paper is slid and retracted on the reverse feed preventing member, and then the next printing is performed. Feed the paper
Characterized in that that.

[0007]

According to the present invention, the paper feed path is blocked by the reverse feed prevention member except that the paper is fed to the paper feed path. The rear end does not enter the paper feed case.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. 1 is a perspective view of a paper feeding case of the paper feeding apparatus according to the present invention, FIG. 2 is a partially broken side view of the same, and FIG. 3 is a partially broken side view showing a paper returning state. In these figures, the same components as those of the prior art are denoted by the same reference numerals, and detailed description is omitted. Reference numeral 8 denotes a fixing member which is formed in a long shape with a thin plate-like spring material, and is detachably attached to the paper feeding case 1 so as to be bridged over the upper end surface of the front opening of the paper feeding case 1. It is attached, three notches 8a are provided, and hinge portions 8b are formed by bending vertically upward at both ends of the front part.

Reference numeral 9 denotes a thin plate reverse feed prevention member. At both ends, an engagement portion 9a with which the tip end of the roller arm 7 engages is provided, and the engagement portion 9a has a hinge 9b extending vertically downward. It is bent. The reverse feed preventing member 9 is supported by a pin 10 fitted in the hinge portion 9b and the hinge portion 8b of the fixing member 8 so as to be swingable about the pin 10. Normally covers the upper end surface of the front portion of the paper feed case 1 by its own weight, and shuts off the paper feed path 11 a to the paper guide 11.

Next, a paper feeding operation and a paper returning operation of the paper feeding device configured as described above will be described. In order to perform the paper feeding operation, the roller arm 7 is driven to swing in the direction A, as shown in FIG. 2, and the paper feeding roller 6 is brought into contact with the photographic printing paper 4 through the notch 8a of the fixing member 8. At this time, the roller arm 7
The lower end of the is engaged with the engaging portion 9a of the reverse feed prevention member 9,
The reverse feed prevention member 9 is rotated in the direction C about the pin 10 to open the paper feed path 11a. Open paper feed path 11
When the photographic paper 4 is sent out to the position a, the leading edge of the photographic paper 4 is nipped by the paper feed roller 15, and the paper feed roller 15 rotates to further feed the photographic paper 4, and the rear end of the photographic paper 4 is fed to the paper feed case. The roller arm 7 swings in the direction B at the time when the sheet is fed from the position 1, and the sheet feeding roller 6 is retracted upward. When the roller arm 7 swings in the direction B, the reverse feed prevention member 9 is disengaged from the roller arm 7 at the engaging portion 9a, and rotates in the direction D by its own weight to move the sheet feeding path 11a again. Cut off.

Since the paper feed path 11a is blocked by the reverse feed prevention member 9, even if the printing of the first color is completed and the photographic paper 4 is returned in the F direction in preparation for the printing of the second color,
The rear end of the printing paper 4 slides on the upper surface of the reverse feed prevention member 9,
Since the conveyance path is different from that at the time of paper feeding and does not enter the paper feeding case 1, it does not come into contact with the separation claw 5 or is not affected by static electricity or the like with the stored printing paper. , Electrostatic attraction is prevented.

FIGS. 4 to 6 show a second embodiment of the present invention. In the second embodiment, the fixing member 20 for pivotally supporting the reverse feed preventing member 9 is mounted on the printer apparatus main body side, that is, in a conventionally well-known case storage chamber in which the paper feed case 1 is stored. In the second embodiment, even if the roller arm 7 swings in the direction B, the roller arm 7 does not engage with the reverse feed prevention member 9.

In such a configuration, the roller arm 7
Is rotated in the direction A, and the paper feed roller 6 is pressed against the printing paper 4. At this time, since the reverse feed prevention member 9 does not engage with the roller arm 7, the paper feed path 11a remains shut off as shown in FIG. As shown in FIG. 5, when the photographic printing paper 4 is pushed out of the feeding case 1 by the feeding roller 6, the reverse feed preventing member 9 is pushed by the leading end of the pushed out printing paper 4 to the pin 1
The photographic paper 4 is sent out to the paper feed path 11a because the photographic paper 4 is rotated in the direction C against its own weight around 0. And
When the photographic paper 4 is completely fed out of the paper feed case 1, the reverse feed prevention member 9 again rotates in the direction D by its own weight to shut off the paper feed path 11a as shown in FIG. Therefore, even if the photographic paper 4 is returned in preparation for printing of the second and subsequent colors, the photographic paper 4 slides on the reverse feed prevention member 9 and, as in the first embodiment described above, Adsorption by static electricity is prevented without coming into contact with the separating claw 5 or without being affected by static electricity or the like with the stored printing paper.

In the first embodiment, the opening of the paper feed path 11a of the reverse feed preventing member 9 is performed by engagement with the roller arm 7, but the sheet is fed out as in the second embodiment. It may be carried out by using the photographic paper 4, and similarly, in the second embodiment, it may be carried out by engaging with the roller arm 7 as in the first embodiment.

[0015]

As described above, according to the present invention, the paper feeding path is interrupted and the paper driving force applying means engages with the paper driving force applying means when the paper driving force applying means abuts on the paper, thereby feeding the paper. A reverse feed preventing member for opening the path is provided, or the reverse feed preventing member is engaged with the paper fed by the paper driving force applying means to open the paper feeding path so that when the paper is returned. Since the paper does not enter the paper feeding case, the occurrence of paper jam is prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view of a paper feed case of a paper feed device according to the present invention.

FIG. 2 is a partially broken side view of the sheet feeding device according to the present invention, showing a sheet feeding state.

FIG. 3 is a partially broken side view of the paper feeding device according to the present invention, showing a paper returning state.

FIG. 4 is a partially cutaway side view of a second embodiment of the sheet feeding device according to the present invention.

FIG. 5 is a partially cutaway side view of a second embodiment of the sheet feeding device according to the present invention, showing a sheet feeding state.

FIG. 6 is a partially cutaway side view of a second embodiment of the paper feeding device according to the present invention, showing a paper returning state.

FIG. 7 is a partially cutaway side view of a conventional sheet feeding device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paper feed case 4 photographic paper 5 separation claw 6 paper feed roller 7 roller arm 8 fixing member 9 reverse feed prevention member 9 a engaging portion 11 a paper feed path 12 ink ribbon 13 thermal head 14 platen roller 15 paper feed roller

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B41J 11/00 B41J 13/00 B65H 3/06 340

Claims (1)

(57) [Claims] 1. A sheet feeding device for feeding the uppermost sheet one by one to a sheet feeding path one by one by a sheet driving force applying means capable of freely contacting and separating the sheets housed in a sheet feeding case. A reverse feed prevention member is provided to cut off and engage the paper driving force applying means when the paper driving force applying means abuts on the paper to open the paper feeding path . A paper feeder , wherein the paper is slid and retracted on the reverse feed prevention member when the paper is reversely fed, and then the paper is fed so as to perform the next printing .