JPH0158088B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feeding device for electrophotographic copying machines, printing machines, etc.

2. Description of the Related Art Conventionally, cut sheet-shaped recording paper used in copying machines and the like has recording paper cassettes that can be stored according to their sizes, and a user selects one of these cassettes as necessary and loads the paper into the machine. At this time, it is necessary to determine which type of recording paper is currently loaded in the cassette inside the machine and determine the movement of the optical system, etc., so an optical means such as an optical sensor or a micro Mechanical means such as switches are used.

Of these, optical means, that is, a light emitting part on one side,
A sensor is installed on the other side to detect the light, and the method of detecting the light by changing the state of blocking the light depending on the type of cassette is durable because there is no mechanical contact. However, since the conventional sensor was fixed to the cassette loading section, it may not be possible to insert the cassette correctly, or if the paper cassette is inserted facing one side due to mechanical play between the paper feed table and the paper cassette. It may not be possible to read the type information, which may cause malfunction.

On the other hand, a mechanism that uses a plurality of microswitches to discriminate between cassettes has also been used.

An example of a conventional cassette discrimination method using a plurality of microswitches will be explained.

Figure 1 shows the conventional method before loading the cassette and the second stage.
The figure shows the cassette being loaded. As shown in the figure, a plurality of micro-switches 1 as detectors are fixed to the front end of a cassette loading table 3 as a paper feed table, and a protrusion 4 is provided on the front end surface of each cassette 2. The determination is made by pressing the actuator 5 of the micro switch 1 that indicates.

Originally, the micro switch 1 is in the ON state when the actuator 5 is between the operating position X and the operating limit position Y, as shown in FIG. Therefore, in the conventional system, the microswitch is fixed, and the actuator 5 of the microswitch 1 is pushed by the protrusion 4 on the cassette so that it is located between X and Y shown in FIG.
If the actuator 5 is not pushed into this X-Y position, the switch will not turn on, and if it is pushed too far, there is a high possibility that the microswitch 1 itself will be damaged.

For this purpose, positioning foot 6 (second
) to the front surface of the protrusion 4, and the precision of the fixing position of the micro switch 1 has also been made strict, so that the front end of the protrusion 4 will be within the range between X and Y in Fig. 3 even when assembled. The conventional method was to make the position of each microswitch adjustable, and then assemble the cassette while adjusting it once the cassette was inserted.

However, in such a conventional configuration, it is difficult to accurately process or adjust the dimensions between the positioning foot 6 and the front surface of the protrusion 4, which are relatively long distances, and the dimensions between the hole 7 and the micro switch 1, which are combined with the positioning foot 6. It was necessary to do so, which caused an increase in costs. Furthermore, even if the adjustment is made once, there is a problem in that if there are variations in the structure of the cassette itself, the reliable operation of the microswitch is impaired. As a countermeasure, it was considered to lengthen the actuator 5 of the microswitch to increase the distance between X and Y, thereby increasing the adjustment allowance, but this could not be said to be a sufficient improvement.

The present invention eliminates these conventional drawbacks and provides a paper feeding device that does not require high processing precision, does not require adjustment, and does not damage the detector.

That is, the present invention includes a paper feed tray, a recording paper cassette that is attached to and removed from the paper feed tray, and a recording paper cassette that is provided on the paper feed tray side and that is pushed and attached by the recording paper cassette when the recording paper cassette is attached to the paper feed tray. a movable plate that moves to follow the cassette against a biasing member; a plurality of detectors mounted and supported on the movable plate for reading type information of the recording paper cassette mounted on the paper feed tray; and a recording paper cassette side. A paper feeder, characterized in that the paper feeder is provided with an operating member that selectively acts on a plurality of detectors on the movable plate to make the detectors sensitive when the recording paper cassette is mounted on the paper feeder. The gist is the device.

A specific example of the present invention will be explained with reference to FIGS. 4 and 5. FIG. 4 shows the state before the cassette is loaded, and FIG. 5 shows the state while the cassette is being loaded.

Here, a micro switch 11 as a detector for cassette discrimination is attached to a movable mounting plate 12, and the mounting plate 12 is attached to a cassette loading base 1 as a paper feeding base.
It is installed at the front end of 3 so as to be pressed by a spring member 14 as a biasing member. On the other hand, the front end surface 16 of the cassette 15 has a protrusion 17 which is an operating member for operating the corresponding micro switch.
and another protrusion 18 which pushes the mounting plate 12 against the spring member 14.

With this configuration, the cassette 15 is loaded onto the loading table 13.
When loaded, the protrusion 17 pushes the actuator 19 of the micro switch, and the protrusion 18
pushes the movable mounting plate 12 itself in the direction of arrow Z.

With this configuration, even if the positioning accuracy of the cassette 15 is somewhat poor or the cassette is forcibly pushed in, the mounting plate 12 itself can escape in the Z direction, so there is no need to apply excessive force to the micro switch 11, and it will not break. be prevented from being Moreover, in order to operate the actuator 19 reliably, precision is required only for the difference in length between the protrusions 17 and 18, and high precision can be easily achieved structurally. Furthermore, since a plurality of microswitches constitute one unit, there is no need to position each microswitch one by one as in the prior art, and there is an advantage that the assembly process is simplified.

Next, another specific example according to the present invention is shown in FIGS. 6 and 7.
This will be explained along the diagram. 6A and 6B are views before loading the cassette, and FIGS. 7A and 7B are views during loading.

In this example, a protrusion 2 is provided on the front end surface 16 of the cassette 15.
This configuration is the same as the example shown in FIGS. 4 and 5, except that only one 0 is provided and the microswitch mounting plate 12 is rotatably mounted on the shaft 21. That is, when the cassette 15 is loaded, the projection 20 pushes the actuator 19 of the corresponding microswitch 11, and further rotates the entire microswitch mounting plate 12 in the Z direction against the force of the spring member 14. In this case, the protrusion 20 is attached to the mounting plate 1.
2, the actuator 19 will operate reliably even if there is some variation, and even if it is pushed in too much, the microswitch will escape due to the rotation of the mounting plate 12, and no damage will occur. .

In the illustrated example, cassette selection protrusions 17 (FIGS. 4 and 5) and 20 (FIGS. 6 and 7) for the micro switch 11 are provided on the front end surface 16 of the cassette 15.
For example, two micro switches 11 are provided with two protrusions and are turned on at the same time.
The type of cassette may be determined based on a combination of the following.

The protrusions 17 and 18 or the protrusion 20 may be formed in a shape that acts on the actuator 19 of the microswitch 11 or the microswitch mounting plate 12, and may be provided on the side or bottom surface of the cassette 15. Further, in particular, the protrusion 18 may be provided on the microswitch mounting plate 12.

As described above, according to the present invention, the following advantages can be obtained.

(1) The type of cassette can be read accurately even if the cassette is loaded at an angle due to mechanical play between the cassette loading section and the cassette.

(2) Even if the cassette is not inserted correctly to the predetermined position, the type of cassette can be read accurately.

(3) Since the detector group has an escape configuration, it will not break. (4) There is one or no place that requires precision, which reduces manufacturing costs.

(5) There are no malfunctions due to variations in cassette dimensions.

(6) After installing the switch, there is no need to adjust the position of the detector for each machine, improving assembly efficiency.

[Brief explanation of drawings]

Figures 1A and B are a plan view and a side view of a conventional paper feeding device before the cassette is stored, Figures 2A and B are a plan view and a side view of the conventional paper feeder while the cassette is being stored, and Figure 3 is a side view of the conventional paper feeder. Figures 4A and 4B are diagrams showing the operating range of the microswitch, and Figures 4A and 4B are a plan view and a side view of the sheet feeding device according to an embodiment of the present invention before it is stored in the cassette.
Figures A and B are a plan view and a side view showing the state during storage of the cassette, Figures 6A and B are a plan view and side view showing the state of another embodiment before the cassette is stored, and Figures 7A and B.
FIG. 2 is a plan view and a side view showing a state in which the cassette is being stored. 1 and 11 are micro switches as detectors,
2 and 15 are recording paper cassettes, 3 and 13 are cassette loading tables as paper feed trays, 4, 17, 18, and 20 are projections, 5 and 19 are actuators, 6 is a positioning foot, 7 is a hole, and 12 is a movable A mounting plate, 14 a spring member as a biasing member, and 16 a front end surface.

Claims (1)

[Scope of Claims] 1. A paper feed tray, a recording paper cassette that is attached to and removed from the paper feed tray, and a recording paper cassette that is provided on the paper feed tray side and that is pushed by the recording paper cassette when the recording paper cassette is attached to the paper feed tray. a movable plate that moves to follow the cassette against a biasing member; a plurality of detectors mounted and supported on the movable plate for reading type information of the recording paper cassette mounted on the paper feed tray; The recording paper cassette is provided on the cassette side and selectively acts on the plurality of detectors of the movable plate to make the detectors sensitive when the recording paper cassette is mounted on the paper feed tray. Paper feed device.