JPS5842349Y2 - paper detection device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a paper detection device for a non-impact printer such as a laser beam printer.

Conventionally, a paper running abnormality detection device uses a sensor 2.3 as shown in FIG. 1 or 2, and a micro switch as shown in FIG. There was one that used 6.

However, in these systems, it is necessary to use two independent types of sensors: a paper running abnormality detection sensor and a paper centration sensor.

The present invention uses one type of sensor to detect paper running abnormality and to detect paper set on a tractor.

Non-impact printers generally form an image on the paper surface while running a continuous slip (hereinafter referred to as paper), and since the paper length of one page is an integral multiple of 0.5 inch, the paper run is always 0. By focusing on the fact that the pitch of the paper sprocket holes is 0.5 inches, and by placing one type of senna in the middle of the sprocket holes, it is possible to detect paper running abnormalities and to detect paper set on the tractor. It is designed to make the user perform the following steps.

When the paper feed operation is stopped, it is detected that paper is set without detecting the sprocket holes, and during the paper feed operation, the paper feed operation is performed normally by checking the cycle of detecting the sprocket holes. The device is designed to detect when a person is present.

FIG. 4 shows the continuous paper 1 for information processing.

A reflective sensor 2 is placed on the back side of the paper 1 at a position midway between the center line of the feed hole 1a.

This may be the transmission type sensor 3 shown in FIG.

While the non-impact printer is printing, the paper 1 is continuously fed at a constant speed, but when it stops, it always reaches a position that is an integral multiple of 0.5 inches.

On the other hand, since the size of the feed hole 1a of the paper 1 is an integral multiple of 0.5 inches, the correspondence between the sensor 2 and the feed hole 1a is as shown in FIG.

The pattern is shown in the time chart of FIG.

In FIG. 5, tl is the time required to feed paper 1 by 0.5 inch.

When the paper is stopped, the reflective sensor 2 is in the middle position of the feed hole 1a, so the light emitted from the light emitting element 2a is reflected on the back surface of the paper 1 and reaches the light receiving element 2b, which turns on. .

Status S1 indicates that the paper feeding operation is stopped, and status S2 indicates that the paper feeding operation is in progress.

In the status of Sl, it is determined whether paper 1 is set by monitoring whether the sensor output is on or not, and in the period of S2, the paper feeding operation is performed by monitoring the time of t2. Determine whether it is being performed normally.

FIG. 6 shows an example of a specific logic circuit.

FIG. 7 shows the levels of the respective signals in FIG. 6.

In FIG. 6, the one-shot 12 is of a retriggerable type, and its set time t3 is set in the relationship t3 > t2.

The FEED signal is a signal that remains at logic 1 during paper travel.

In the time chart of FIG. 7, when the FEED signal is logic O, sigA becomes logic 1, indicating that paper 1 is not set at this time.

Also, when the FEED signal is logic 1, if the sprocket hole 1a cannot be detected within 13 hours, or the sprocket hole 1a
If there is no detection, or if there is an abnormality in paper feeding, one shot 12 will be turned off and the sig
B becomes logic 1.

According to the present invention, two types of checks, such as paper setting and normality of paper running, can be performed using one sensor output, so only one type of sensor is required, whereas two types were conventionally required.

[Brief explanation of the drawing]

1 and 2 are side views showing an example of a paper running abnormality detection sensor, FIG. 3 is a side view showing an example of a paper set detection sensor, and FIG. 4 is a front view showing continuous paper for information processing. Figure 5 is a timing diagram of the senna output in the present invention;
The figure is a block diagram of an embodiment of the logic circuit in the present invention.
FIG. 7 is a time chart explaining the operation of FIG. 6. FIG. 8 is a side view showing the mounting state of the senna according to the present invention. In the figure, 1 is a paper feed hole, 2 is a reflection type sensor, 3 is a transmission type sensor, 4 is a paper presser, 5 is a plate, and 6
6a is a microswitch, 6a is an actuator, 7 is a resistor, 8 is a capacitor, 9 is an operational amplifier, 10 is an AND gate, 11 is an inverter, 12 is a retriggerable one-shot, 13 is a tractor, and 14 is a tractor cover.

Claims (1)

[Scope of utility model registration request] In a non-impact printer that uses continuous slips for information processing with sprocket holes every 1/2 inch, when the paper stops at the correct position, the sprocket hole is detected at an intermediate position on the line connecting the centers of the front and rear sprocket holes. A paper detection device equipped with an optical sensor for detecting paper.