JPH0326623A - Sheet feeder - Google Patents

Abstract

PURPOSE:To eliminate supply of electric signals from a main body printer to a sheet feeder by providing a middle connection gear integrated with an idle gear for transmitting the power of a platen to the idle gear, forming teeth surfaces only in part of the circumference of the middle connection gear, and composing to rotate a pickup roller for a constant quantity. CONSTITUTION:A sheet biting a platen 3 is fed by a roller pressure between a pressure roller and the platen 3. In the meanwhile, while the supplied sheet 11 is under a pickup roller 8, the pickup roller 8 rotates by friction of the sheet, and the pickup roller 8 is not rotated after the end of the paper passes the underside of the roller. In this case, for a gear ratio of 1:3 between a platen gear 4 and a sheet feed gear 5, a middle connection gear 6 makes one round by a line feed instruction for 13.5'' to be newly engaged with a gear 7 and rotates the pickup roller 8 for feeding a new sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power transmission mechanism for a sheet feeder.

[Conventional technology]

A device that automatically feeds paper sheets one by one to a printer is called a sheet feeder. Conventional sheet feeders have a step motor on the sheet feeder side as a driving source, and the rotation of the step motor rotates the big up roller that takes out the paper from the hopper, feeding the paper to the rear of the platen. After feeding the paper to the rear of the platen, rotate the platen and bring the paper to the printing position.

A one-way clutch is provided between the pickup roller and the step motor, and after the paper is caught on the platen, the pickup roller idles according to the movement of the paper and does not act as a brake. In other systems, the power from the platen is taken out to the sheet feeder side using a gear connection, and a spring clutch is provided between the shaft and the shaft that drives the pickup roller.
The rotation of the platen rotates the pickup roller and takes out the paper. After the paper is stuck to the platen, the spring clutch is released to stop the rotation of the big up roller and the platen is used to feed the paper. [Problem to be solved by the invention] Therefore, a circuit for driving a step motor or a spring clutch is required, and inevitably a power supply and other cable connections from the printer are required. [Means for Solving the Problems] The present invention transmits the power of the platen to the idle gear, and has an intermediate gear paired with the idle gear. The mechanism is to rotate the roller a certain amount. [Example] Next, an example of the present invention will be described with reference to the drawings. Figure 1 shows the transmission structure to the roller section of the present invention. 1 rotates the platen 3 via the idle gear 2 using the LF motor of the printer body. It has a platen gear 4 on the shaft opposite the platen. The gear 5 on the sheet feeder is connected to an intermediate gear 6 which has teeth only on a part of its circumference.
Gear 6 is transmitted to gear 7, and pick rollers 8, 8
Rotate ′. The intermediate gear 6 feeds the paper with the big roller 8, and has teeth cut enough to rotate the big roller until the leading edge of the paper is caught between the pressure roller under the platen and the platen, and the other circumferences are It is made so that gear 7 can idle by reducing its diameter. The paper stuck to the platen is fed by the roller pressure between the pressure roller and the platen. While the fed paper is under the pick roller 8, the pick roller 8 rotates due to the friction of the paper, but when the edge of the paper passes under the roller, the pick roller 8 does not rotate. Normally the platen diameter is φ36.38 and 4 times per circumference.
．． It is 5~. Platen gear 4 and seat feed gear 5
If the gear ratio is 1:3, if a line feed command is sent for 13.5'', the interlocking gear 6 will go around once, engage the gear 7 again, rotate the big roller 8, and feed a new sheet of paper. The paper is guided by stacked side plates 9 and 9', and both ends of the paper are held down by claws 10 and 10' at the tips of the plates.The entire paper is pressed from below against the rollers by a spring, and the paper is held down by the claws. The paper used in such sheet feeders is usually 1" long, so if you set the printer's form feed length to 13.5", it will feed out only the top sheet. Paper is fed continuously at intervals. After stacking the paper on the sheet feeder, by turning the platen knob 12 by hand, the paper is fed out and wrapped around the platen until it reaches a desired position. TOF of the printer at that position
(If the top of form is set, the form feed length (13.5") is sent. If a line feed command is sent, the next sheet will be fed to the same position. There is no need to supply power or electrical signals from the printer to the sheet feeder.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention. 1... LF motor, 2... Idle gear, 3...
Braten, 4...Platen gear, 5...Sheet feeder gear, 6...Interlock gear, 7...Gear, 8...
・Big up roller, 9...Side guide, 10・
...Claw, 11...Paper, 12...Platen knob.

Claims (1)

[Claims] The platen gear and sheet feeder gear are compatible.
It has a gear ratio that causes the sheet feeder gear to rotate once when the platen rotates a little longer than the paper length on the circumference of the platen, and a gear with approximately the same diameter and a tooth shape for a certain period of time is directly connected to that gear. A sheet feeder that has a pickup roller on the shaft of the gear that is in contact with the partially toothed gear.