JPH0322195Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to a paper feeding device that sandwiches recording paper between two rolls and feeds the recording paper by rotation of the rolls.

<Prior Art> Conventionally, in a paper entry mechanism consisting of two gate rollers and a paper guide plate arranged parallel to each other in contact with each other as shown in FIG. 3, the upper gate roller 12 and the lower gate roller 11 are There were also cases where one side was made of a rubber-based material with a high coefficient of friction, and there were cases where one side was made of a rubber-based material and the other material was made of a combination of materials such as steel. In either case, there were cases in which the leading edge of the paper came into contact with a rubber-based roller having a high coefficient of friction before reaching the contact point between the two gate rollers. The advance of the paper is then obstructed there, and the paper cannot reach the contact point between the two gate rollers. In other words, variations occurred in the initial position of the leading edge of the paper, making it impossible to obtain high printing position accuracy.

<Purpose> The purpose of this invention is to ensure that the leading edge of the paper always reaches the contact point of the two gate rollers without getting caught on the way.
The purpose is to eliminate variations in the initial position of the leading edge of paper and obtain high printing position accuracy.

<Embodiment> The present invention is composed of a gate roller with a large coefficient of friction, a gate roller with a small coefficient of friction, and upper and lower paper guide plates. An embodiment will be explained using FIGS. 1 and 2. The lower gate roller 1 is made of a material with a high coefficient of friction, and is connected to a drive source (not shown). On the other hand, the upper gate roller 2 is made of a material with a small coefficient of friction. First, the pick-up roller 7 rotates to take out a sheet of paper from the paper cassette 6 and send it to the gate roller.
At this time, the upper paper guide plate 3 and the lower paper guide plate 4 are
5a to the surface of the upper gate roller 2.

The upper gate roller 2 is provided with grooves 8 at multiple locations over its entire width, and the tip of the comb-like upper guide plate 3 is inserted into these grooves, so that the upper guide plate 3 and the upper gate roller 2 The gap between the two is virtually zero. In other words, the leading end 5a of the paper 5 is guided onto the surface of the upper gate roller 2 until the end. The tip of the lower guide plate 4 is placed as close as possible to the contact points of the two gate rollers. Also, in order to reduce the angle with the paper coming in from the paper cassette 6, it is bent in the middle to smoothly connect the point where the paper comes in and the point where the paper comes out. It is also possible to connect them with a curved line. The gap between the tip of the lower guide plate 4 and the upper guide plate 3 is made as small as possible within a range sufficient for one sheet of paper to pass through, thereby regulating the degree of freedom of the paper so that the paper does not come off the surface of the upper gate roller 2. do. When the paper is further fed by the pick-up roller 7, the leading edge of the paper slides on the surface of the upper gate roller 2 and reaches the contact point between the two gate rollers as shown in FIG. Because the friction coefficient of the upper gate roller 2 is small, the leading edge of the paper
5a always reaches the contact point of the two gate rollers without getting hit on the way. In other words, the initial position of the leading edge of the paper can be kept constant. Then, the leading edge 5a of the paper comes into contact with the lower gate roller 1 for the first time at this contact point. Through the above operations, the positional accuracy of the leading edge of the paper has been reduced from about ±1 mm to ±0.5 mm, and the inclination of the paper has been reduced from about ±0.5° to ±0.1°. Even when manually feeding cut sheets without using a paper cassette, the same effect can be obtained by changing the feeding of the pick-up roller 7 shown in FIGS. 1 and 2 to manual feeding.

<Effects> As described above, according to the present invention, the recording paper fed by the pick-up roller is forcibly reduced to a friction coefficient by the lower paper guide member extending toward the gate roller side, which has a smaller friction coefficient. can be placed along the surface of a small gate roller.

Therefore, the recording paper slides on the surface of the gate roller, which has a small coefficient of friction, and reaches the surface parallel to the contact line between the pair of gate rollers, so that printing starting from the leading edge of the recording paper is oriented with respect to the paper surface. It is done accurately without being slanted or out of place.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is a sectional view showing its operating state, and FIG. 3 is a diagram showing a conventional example. 1, 11... lower gate roller, 2, 12... upper gate roller, 3, 13... upper paper guide plate, 4,
14... Lower paper guide plate, 5, 15... Paper, 6, 1
6...Paper cassette, 7,17...Pick-up roller.

Claims (1)

[Claim for Utility Model Registration] In a paper feeding device that feeds the recording paper stacked in a paper cassette one by one by a pick-up roller, one is made of a material with a large friction coefficient and the other is made of a material with a small friction coefficient. a pair of gate rollers 1 and 2, which are made of a material and transport the recording paper after the leading edge of the recording paper 5 fed by the pick-up roller 7 hits the contact line; and the paper cassette. 6 and the gate rollers 1, 2, and guide the recording paper 5 fed by the pick-up roller 7 to the contact line of the gate rollers 1, 2. The paper guide means includes an upper paper guide member 3 that guides the front surface of the recording paper 5, and a lower paper guide member 4 that guides the back surface of the recording paper 5, Until it hits the contact line, the recording paper 5 is moved by the gate roller 2 having a small coefficient of friction.
The tip of the lower paper guide member 4 is moved along the surface of the gate roller 2 having a small coefficient of friction.
A paper feeding device characterized by extending close to the side.