JPH0515468Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention consists of a paper loading table that can be raised and lowered to hold paper, and a paper loading table that engages with the topmost paper on the loading table to sequentially load the sheets of paper. The present invention relates to a paper feeding device equipped with a feeding means for feeding paper, and relates to one that supplies paper to an image forming apparatus such as a copying machine, for example.

[Conventional technology]

Generally, copy paper is supplied to an image forming device such as a copying machine using a box-shaped cassette that is attached to the cassette loading slot, but this cassette is limited in the amount of paper that can be stored at one time, and depends on the paper size. It is troublesome to have to replenish paper frequently.

Therefore, a large-capacity paper feeding device is attached to the cassette loading opening, and paper is sequentially fed from a paper loading table loaded with a large amount of paper to the entrance roller of the cassette loading opening using a paper feeding means such as a roller or an endless belt. Proposed.

This is not limited to the type that docks in the cassette loading slot, but also for copying machine paper feed devices where the paper tray is raised toward the paper feed means as the paper gradually decreases. It is necessary to provide means for detecting the presence or absence of paper, and level detection means for detecting when the decrease in paper has reached a certain amount.

Conventionally, this paper presence/absence detection means, for example, an empty sensor, is buried in the lower part of the paper table to detect whether or not paper is placed thereon. Further, the level detecting means, for example, a level sensor, is engaged with the topmost sheet of paper, and when the amount of paper decrease reaches a predetermined amount, a signal is sent to a driving means that raises the paper tray. There is.

On the other hand, the paper feeding means is activated by a signal from the copying machine or by itself detecting that no paper is prepared at the entrance of the copying machine, and feeds out the paper.

In addition, the driving means, the paper presence/absence detection means, and the level detection means are arranged in parallel at the same level position, and when the paper presence/absence detection means is turned ON (or OFF), the level detection means is turned OFF.
It is also possible to detect out of paper when it is turned on (or ON).

[Problem that the invention attempts to solve]

However, if the device is activated when a paper feed instruction signal is received regardless of the state of the paper feeding device, there is a risk that the device will be activated during paper replenishment or paper jam processing. Even if this problem is resolved by installing a special safety switch, if a paper feed instruction signal is issued while the paper tray is moving from the replenishment position to the paper feed position,
The paper feeding means cannot feed out the paper, causing problems such as being treated as a paper jam.

Therefore, it is conceivable to treat the instruction signal sent to the paper feeding means as invalid until the level sensor that detects the amount of paper engages with the paper. However, in this case, the level sensor detects a certain amount of level drop even while the paper is being fed, and the paper feed instruction signal is treated as invalid while the paper loading table is raised.
This is inconvenient because it is necessary to interrupt the copying operation and wait, and the continuous copying operation is frequently interrupted.

At the same time, if the timing between the copying machine and the paper feeding device is set so that paper is prepared for a predetermined copying process after a certain period of time from the paper feeding instruction signal, the level sensor detects when the amount of paper is decreasing during this time. The paper feed cycle per sheet must be set assuming the most inopportune case in which the paper is detected, the paper table is raised, the paper feed means is activated, and the paper is sent to the copying process. The problem is that it becomes long.

On the other hand, the driving means, the paper presence/absence detection means, and the level detection means are arranged in parallel at the same level position, and when the paper presence/absence detection means is turned ON (or OFF), the level detection means is activated.
If the paper out state is detected when it is OFF (or ON), malfunctions may occur in the raising and lowering of the paper tray due to installation errors in each means, curvature of the paper, or tilt of the paper tray. There is a problem that occurs.

[Purpose of invention]

This idea allows paper to be fed continuously and smoothly without invalidating or delaying the paper feed instruction signal when the paper tray is moved up due to a decrease in the amount of paper. The purpose is to obtain a paper feeding device that does not cause this problem.

[Example of idea]

An embodiment of this invention will be described below based on the drawings.

As shown in FIG. 1, a paper feeder B is attached to a cassette loading port 1 of a copying machine A. The copying machine A has a well-known configuration, and has a copying optical system, a transfer/printing mechanism, etc. incorporated therein. Further, the cassette loading port 1 is provided with an entrance roller (paper feeding roller) 2. Normally, when the paper feeder B is not used, a cassette loaded with paper is loaded into the cassette loading slot 1, and the entrance roller 2 engages with the top paper of the cassette to feed it out and send it to the feed roller 3. ing.

The paper feeding device B is composed of a paper ejection section B1 that fits into the cassette loading port 1, and a paper storage section B2 that stores and stacks paper.

The paper delivery section B1 is composed of a delivery guide 4 that guides the paper delivered from the paper storage section B2 to the entrance roller 2.

The paper storage section B2 is a paper mounting table 6 that stores and stores paper.
and a paper feeding means 7 that engages with the uppermost paper on the paper table 6, and the individual structures thereof are widely known.

The paper loading table 6 is supported in a guide groove 9 provided in a paper storage frame 8 so as to be able to rise and fall freely, and is wound around and supported by a drive pulley 11 connected to a drive motor M via a suspension member 10 such as a wire or belt. ing.

Therefore, by rotating the drive pulley 11 in either the forward or reverse direction, the paper table 6 can be raised or lowered. The paper feed means 7 is composed of rollers, endless belts, etc., and engages with the uppermost paper on the paper table 6, and its rotation feeds the paper toward the paper delivery section B1.

The sheets fed out from the paper storage section B2 may be separated one by one and fed out, or they may be fed continuously in multiples, but in the case shown, the sheets being fed out are separated one by one by the corner claws 12. There is.

Further, a sensor S1 is disposed on the unloading guide 4 below the entrance roller 2, and when this sensor S1 does not detect paper, that is, when no paper is prepared on the entrance roller 2, the paper feeding means 7 is driven. The paper is fed out from the paper storage section B2.

At the same time, this sensor S1 determines that the paper is jammed when the paper does not arrive after a predetermined period of time after the paper feeding means 7 is activated, and lowers the paper tray 6.

As shown in Fig. 2, an empty sensor ES is used as a paper presence/absence detection means to detect whether or not paper is stocked on the paper tray 6, and detects the amount of decrease in the topmost paper on the paper tray 6. A level sensor LS serving as a level detection means is arranged at a position where it engages with the uppermost paper on the paper table 6.

These two sensors ES and LS may be optical sensors, so-called photosensors, or microswitches, but in this embodiment, photosensors are used because of their good responsiveness.

The two sensors ES and LS attached to the machine frame at the top of the paper table 6 are connected to levers E1 and L1, respectively.
is extended so as to engage with the topmost paper on the paper table 6. At the same time, the paper feed means 7 is swingable (bearing on a bracket) or supported on a guide groove in the vertical direction so as to follow the topmost paper as the number of paper decreases. It can be moved in any direction.

As shown in FIG. 3, a recessed part 14 for empty detection is formed on the surface of the paper table 6 facing one lever E1, and the sensor ES and the lever E1
Paper empty is detected by the recessed portion 14 and the recessed portion 14. Also sensor LS and lever L1
The paper level is detected by

Furthermore, the empty sensor ES is installed at a lower position (head d) than the level sensor LS, so that the empty sensor ES side responds quickly to the rise of the paper table 6.

The paper loading table 6 is controlled to move up and down as follows by turning ON and OFF the sensors ES and LS.

(a) When ES=OFF and LS=OFF, raise the paper loading table 6.

(b) When ES=ON and LS=OFF, raise the paper loading table 6.

(c) When ES=ON and LS=ON, the paper table 6 is kept stationary.

(d) When ES=OFF and LS=ON, there is no paper.

Both sensors ES and LS configured in this way operate as follows. (1) First, the paper loading table 6 is lowered to the lowest position, the paper is loaded, and a loading completion signal is given, for example, by closing the opening/closing door. At this time, as shown in FIG. 3A, since ES=OFF and LS=OFF, the paper table 6 rises. (2) When the paper feeding means 7 comes into contact with the uppermost paper as shown in FIG. 3B due to the rise of the paper mounting table 6, the state becomes ES=ON and LS=OFF. (The illustrated embodiment starts the paper feeding means 7 in this state, and stops the paper feeding means 7 when the leading edge of the paper reaches the sensor S1.) (3) As shown in FIG. 3C, ES=ON, LS=
When ON, the lifting of the paper loading table 6 is stopped. (4) As paper decreases, ES=ON, LS=
When it is OFF, a level is lowered and an instruction signal to raise the paper loading table 6 is issued. (5) As shown in Figure 3 C, ES=
ON, and when LS=ON, the lifting of the paper loading table 6 is stopped. After that, operations (4) and (5) are repeated as the amount of paper decreases. (6) When ES=OFF, LS=OFF, paper mounting table 6
rise. (7)When ES=OFF and LS=ON, a paper out signal is generated. (In the illustrated embodiment, the paper loading table is automatically lowered to the paper loading position in response to a paper out signal.)
In this way, the signals of the empty sensor ES and the level sensor LS are set, and the paper feed means 7, the empty sensor ES, and the level sensor are
LS are arranged so that when the paper loading table 6 is raised, the uppermost paper first engages with the paper feeding means 7, then the empty sensor ES, and then the level sensor LS. OFF, that is, when there is no paper, or when the paper loading table 6 is lowered even though there is paper, the paper feed instruction signal is disabled so that the paper feed means 7 is not activated by the paper feed instruction signal from the sensor S1 mentioned above. The paper feed instruction signal and the ON state of the empty sensor ES are connected to the drive motor of the paper feed means 7 via an AND element.

In other words, as shown in FIG. 4, the output of the sensor S1 is inverted by the inverting element 13, the output of the inverting element 13 and the output of the empty sensor ES are input to the AND gate 15, and the output of the AND gate 15 is fed. It is connected to the drive motor of the paper means 7, so that the paper feed means 7 feeds paper when the empty sensor ES is in the ON state.

Therefore, the paper loading table 6 is moved from the paper supplying position to the paper feeding means 7.
When moving to the paper feeding position where it engages with the uppermost paper, the paper feeding means 7 and the uppermost paper first engage with each other, as shown in FIG.
Next, push up the empty sensor ES,
Turn on the paper as shown in Figure 3B.
Further, when the paper mounting table 6 rises, the level sensor LS turns ON as shown in FIG. Then, the paper tray 6 overruns and then stops.

The paper feed instruction signal is treated as valid in the states of FIG. 3B and FIG.

When the amount of paper decreases and the level sensor LS turns OFF as shown in Figure 3 B, the paper loading table 6 is advanced, and when the level sensor LS turns ON, its drive is cut off, overrunning the paper loading table 6. stops. During the process of raising the paper tray 6, the paper feed instruction signal is always treated as valid, and the paper is fed to the copying machine A without delay in supply timing. When there is no paper on the paper tray 6, or when a paper jam occurs and the paper tray 6 is lowered, the empty sensor ES turns OFF, and at this time, the paper feed instruction signal is treated as invalid and the paper feed is stopped. The paper means 7 is set inactive.

According to the embodiment described above, as the paper loading table 6 moves up and down, the uppermost paper is transferred to the paper feeding means 7,
Since the empty sensor ES and the level sensor LS are arranged to engage in this order, when the empty sensor ES detects the presence of paper, the paper feed means 7 and the top paper are engaged in a state where paper can be fed. At the same time, the empty sensor ES is used to set the paper feed means 7 in the active and inactive states, so that during the process of repeatedly feeding the paper using the level sensor LS, the paper is fed reliably and without any waiting time according to the paper feed signal. can be supplied.

[Effect of idea]

According to the paper feeding device according to the present invention, there is a paper mounting table that can be raised and lowered, a paper feeding means that engages with and feeds out the topmost paper on the paper mounting board, and detects the presence or absence of paper by detecting the topmost paper. A paper feeding device comprising a paper presence/absence detection means and a level detection means for similarly detecting the amount of reduction in paper, and which raises a paper loading table toward the paper feeding means based on a paper reduction signal from the level detection means, As the paper tray rises, the paper feeding means first engages with the topmost paper on the paper tray, then the paper presence/absence detection means detects the topmost paper, and then the level detection means detects the topmost paper. In addition, while the paper presence/absence detection means detects the presence of paper on the paper tray, a control means is provided which allows the drive of the paper feeding means even if the paper decrease signal is output from the level detection means. Even when the paper tray is raised due to a paper amount reduction signal from the level detection means, there is no need to invalidate or delay the paper feed instruction signal, and the paper is continuously and smoothly fed, and the paper tray is raised and lowered. This has the effect of preventing malfunctions from occurring.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, with Fig. 1 being an explanatory diagram of the overall structure, Fig. 2 being an explanatory diagram of the main parts of the sensor,
3A to 3D are explanatory diagrams of the operating state, and FIG. 4 is a circuit diagram of the signal system. 6...Paper loading table, 7...Paper feeding means, ES...Empty sensor (paper presence/absence detection means), LS...Level sensor (level detection means).

Claims (1)

[Scope of claim for utility model registration] A paper loading table that can be raised and lowered to hold paper;
A paper feeding means that engages with the uppermost sheet of paper on the paper tray and feeds out the sheets one after another; and a paper feed device that detects the presence or absence of paper on the paper tray by detecting the uppermost sheet of paper on the paper tray. and a level detection means for detecting the amount of paper decrease on the paper mounting table by similarly detecting the uppermost paper on the paper mounting table, and detecting a paper reduction signal from the level detection means. In the paper feeding device that raises the paper loading table toward the paper feeding means based on the above, as the paper loading table rises, the paper feeding means first engages with the uppermost paper on the paper loading table, and then the paper The presence/absence detection means detects the topmost paper, and then the level detection means detects the topmost paper, and the paper presence/absence detection means detects the topmost paper on the paper tray and outputs the presence of paper. The paper feeding device further comprises a control means for permitting the driving of the paper feeding means even when a paper reduction signal is output from the level detection means.