JPH0489741A - Sheet conveyance device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sheet conveyance device such as an electrophotographic copying machine and an inkjet recording device that conveys a sheet at high speed.

(Prior art) Conventionally, in a high-speed recording method, the distance from the cassette to the timing sensor is kept as short as possible, and the recording paper is fed at a speed considerably faster than the process speed. By feeding the recording paper, the distance between the recording sheets was widened, and the timing with the image forming unit was determined at the timing roller, and the recording paper was conveyed.

In addition, as a means of utilization, in order to reduce the variation in the starting position of the recording paper from the cassette to separation without increasing the speed too much, shortening the interval or using a transmission type sensor to improve responsiveness, etc. It was being transported.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional example, extremely increasing the conveyance speed causes problems in conveyance, and tends to cause tip breakage, skewing, etc.

In addition, it is difficult to reduce the variation in the starting distance between the separation roller and the recording paper due to the structure, and after the previous recording paper has passed, the next recording paper is detected before the actuator of the detection means returns. rushes in and causes a jam.

However, if the actuator is shortened in order to speed up the return of the actuator, disadvantages arise such as the recording paper slipping under the actuator.

Furthermore, if a transmission type detection means is used to improve responsiveness, the cost will be high.

The present invention has been made in order to solve the problems of the prior art described above, and its purpose is to provide a sheet conveying device that does not cause jams at the detection means even when the sheet conveying speed is increased. It is provided at a cost.

(Means for Solving the Problems) In order to solve the above problems, the present invention includes an interlocking means whose tip abuts the sheet and swings in conjunction with the passage of the sheet, and a movement of the interlocking means. A sheet conveyance device comprising a detection means having a sensor for sensing the sheet, wherein the interlocking means contacts the sheet, and a swinging surface of the interlocking means forms a predetermined angle with respect to the conveyance direction of the sheet. shall be.

Further, it is also preferable that the sheet contacting portion of the interlocking means has a shape that forms a predetermined angle with respect to the conveying direction of the sheet.

(Function) In the sheet conveying device configured as described above, since the swinging surface of the interlocking means is disposed at a predetermined angle with respect to the sheet conveying direction, the interlocking mechanism interlocks with the movement per unit length of the sheet. The amount of movement of the means is increased, and therefore the time required for one swing of the interlocking means is reduced.

(Embodiment) FIGS. 1 and 2 show a first embodiment of the present invention.

In Figure 1, 2 is recording paper as a sheet, 1 is a cassette in which recording paper 2 is loaded, and 3 is recording paper 2 in cassette 1.
4 is a pair of separating rollers 5 that separates the recording paper 2 sent out from the feeding roller 3 into one sheet;
6 is a pair of conveyance guides with a certain interval, 6 is a pair of conveyance rollers, 7 is a registration roller that sends out the fed recording paper 2 at a certain precise timing, and 8 is a sign that the recording paper 2 has arrived. 9 is a conveyance belt that conveys the recording paper 2 at a constant speed, 10 is a recording head that discharges ink to form an image, and 11 is a pair of paper ejection rollers. , 12 is a stand on which the recording paper 2 is placed one by one on the manual feed tray, 13 is a manual feed roller that feeds the recording paper 2 placed on the manual feed tray 12;
4 is a manual feed sensor that detects that the recording paper 2 placed on the manual feed tray 12 is at a predetermined position.

FIGS. 2(a) and 2(b) are diagrams showing the main parts of the first embodiment of the present invention, and 22 is a groove-shaped sensor 26 as a sensor.
It is a mounting plate to which the actuator 24 is attached, and also serves as a stopper for the actuator 24 as an interlocking means.

25 is a return spring that biases the actuator 24 downward at all times when no paper is passed; 23 is the actuator 24;
The actuator shaft is the center of swing and is attached to the conveyance guide 5. Here, the mounting plate 22. Return spring 25. Actuator 24 Actuator shaft 23. The groove-shaped sensor 26 constitutes the detection means 8.

Next, the operation of this embodiment will be explained using FIGS. 1 and 2. In the above configuration, the feed roller 3 is operated by a drive source (not shown) to feed the recording paper 2 from the cassette 1 to the separation roller 4, and the recording paper 2 is separated into one sheet by the separation roller 4 and guided by the conveyance guide 5. , and are transported by transport rollers 6. When the detection means 8 is reached, the actuator 24, which had been urged downward by the return spring 25 of the detection means 8, is moved to the actuator shaft 2 by the recording paper 2.
3 swings upward A, the actuator 24 blocks the groove sensor 26, and the state is ON (state with sheet).
becomes.

At this time, the drive timings of the registration roller 7, conveyance belt 9, and paper ejection roller 11 are determined, and the detection means 8 is turned on.
In this state, the recording paper 2 is fed several mm, forms a loop, stops for a certain period of time, and then is conveyed by the registration rollers 7.

Thereafter, the recording paper 2 is conveyed by a conveyance heald 9 and a registration roller 7, and is discharged by a conveyance guide 5 and a pair of paper discharge rollers 11. For manual paper feeding, the manual feed tray 12
When a sheet of recording paper 2 is loaded by the user and the leading edge turns on the manual feed sensor 14, the manual feed roller 13 is operated and the paper is fed, and thereafter the same operation as on the cassette side is performed.

As shown in FIG. 2(b), the present invention having the above configuration is capable of switching the detection means from ON to OFF by setting the swinging surface E of the actuator 24 at a predetermined angle θ with respect to the recording paper 2.
The amount of movement B of the recording paper 2 up to is reduced by B' (=B
cos θ), the distance between recording sheets can be made smaller, and high speeds can be handled. Note that if the angle θ with respect to the recording paper 2 exceeds the MAX 45°, a jam may occur, so θ needs to be set to 45° or less. In this example, θ=4
It is carried out at 5° (= MAX), and B, B
The difference between ' is B - B ' = B - B cos 45
If the cape is 0.3B and B is set to approximately 23mm, (
B-B') is approximately 7 mm, and the distance between recording sheets can be shortened by 7H.

In contrast to the first embodiment in which the actuator 24 is lowered from the upper surface of the mounting plate 22, the same effect can be obtained by lowering the actuator 24 from the lower surface of the mounting plate 22.

In addition, as shown in FIG. 3, the contact portion F of the actuator 24
is at a predetermined angle, for example 4, with respect to the conveying direction C of the recording paper 2.
A similar effect can be obtained when the shape is made to form an angle of 5°.

Further, the same effect can be obtained with an actuator using a microswitch or the like.

(Effects of the Invention) As explained above, by attaching the interlocking means whose tip end contacts the sheet and swings in conjunction with the passage of the sheet at a predetermined angle to the sheet, the interlocking means can be oscillated once. The time required for the movement is reduced, and sheet conveyance can be carried out at higher speeds at a lower cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a sheet conveying device embodying the present invention, FIG. 2(a) is a longitudinal sectional view of the detection means, FIG. 2(b) is a view of the detection means viewed from above, and FIG. 3 FIG. 2 is a top view of a detection means according to another embodiment of the present invention. Explanation of symbols 2... Recording paper (sheet) 24... Actuator (interlocking means) 26... Groove sensor (sensor) 8... Detection means C... Sheet conveyance direction E.
... Swinging surface F of actuator (interlocking means) ... Seat contact part

Claims (2)

[Claims] (1) A sheet conveyance device comprising a detection means having an interlocking means whose leading end abuts the sheet and swings in conjunction with the passage of the sheet, and a sensor that detects the movement of the interlocking means, the interlocking means A sheet conveying device characterized in that the means is in contact with the sheet, and the swinging surface of the interlocking means forms a predetermined angle with respect to the conveying direction of the sheet. (2) The sheet conveying device according to claim 1, wherein the sheet contacting portion of the interlocking means has a shape forming a predetermined angle with respect to the conveying direction of the sheet.