JP2664252B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a copying machine or a printer, and more particularly, to a cassette for loading sheets (hereinafter referred to as sheets) used in the image forming apparatus. Related to an automatic unloading mechanism.

2. Description of the Related Art Conventionally, a paper cassette used in a copying machine, a printer, and the like can be detached from a main body of the apparatus in order to supply paper or change a paper size. Also,
There are two types of attachment and detachment of the paper cassette to and from the device body: a type that pulls out in the direction of the side of the device body and a type that pulls out in the direction of the front surface of the device body.

2. When replenishing paper, the paper can be supplied without removing the cassette from the main unit.

3. Easy operation since cassette operation is front operation.

For these reasons, the type of pulling out the cassette in the front direction (hereinafter referred to as front loading) is increasing.

Further, in the case of a front loading type cassette, the paper storage section in the cassette must be protruded to the front side of the apparatus main body, and in order to improve the operability in which the moving distance of the cassette is long, the apparatus main body is improved. There has been proposed an auto-loading apparatus in which insertion and withdrawal of a cassette into and out of a cassette are automatically performed by providing driving means.

In the auto-loading device, when the paper in the cassette runs out, it is detected and displayed at an appropriate place on the main body of the device.

(C) Problems to be Solved by the Invention However, in the above-described copying machine of the auto-loading apparatus, when a sheet runs out during copying of a plurality of sheets or the like, a short time after the machine is stopped, no paper is displayed by a display. There is a drawback that the operator is still semi-automatic in terms of replenishing the paper in the cassette, such as when the operator knows that the printer is in the state and then ejects the cassette by pressing the eject key to replenish the paper. Also, if you let an empty cassette be automatically unloaded,
When the cassette is pushed in without replenishing the sheets, there is a problem that the cassette projects again and gets in the way.

Therefore, the present invention provides an automatic loading apparatus that automatically ejects a cassette from the apparatus body when paper in a cassette runs out during copying, and prevents re-ejecting of a cassette when an empty cassette is pushed in. It is an object of the present invention to provide an image forming apparatus provided with:

(D) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances, and a cassette for stacking sheets, an apparatus main body that incorporates this cassette and feeds paper, An image forming apparatus configured to cause the sheet to be carried out of the apparatus main body and provided with driving means provided in the apparatus main body, and sheet presence / absence detecting means for detecting presence / absence of a sheet in the cassette; A cassette unloading control unit that operates the drive unit so that the cassette is unloaded from the apparatus main body in response to a sheet absence detection signal of the presence / absence detection unit; and the cassette unloading control unit operates the drive unit. Thereafter, when the cassette is returned into the apparatus main body, the cassette is unloaded by the drive unit regardless of the sheet absence detection signal of the sheet presence / absence detection unit. The operation is controlled to be stopped.

(E) Operation Based on the above configuration, when the sheets in the cassette are exhausted and the absence of the sheet is detected by the sheet presence / absence detection means, the cassette drive means is controlled by the sheet absence detection signal of the sheet presence / absence detection means. The cassette is unloaded from the apparatus body under the control of the means. After refilling the empty cassette that has been carried out with sheets, the cassette is pushed into the apparatus main body, so that image formation can be resumed.

In the state in which the empty cassette is carried out by driving the driving means, for example, when there is no sheet to be replenished, etc., even if the empty cassette is pushed into the apparatus main body, the empty cassette is driven by the driving means. The unloading operation is controlled by the cassette unloading control means so as to stop.

(F) Example Hereinafter, an example of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the copying machine 1 has a transfer device 5 in the apparatus main body 2 for automatically attaching and detaching the cassette 3. A paper feed roller 6 composed of a plurality of half-moon rollers disposed close to and above the transport device 5 is fixed to a rotatable shaft 7 and feeds the paper S in the cassette 3 to the photosensitive drum 9. Things. The toner image formed on the photosensitive drum 9 by a known means is transferred to a fed sheet S. The transferred sheet S is fixed by a fixing device (not shown) and then discharged outside the apparatus.

As shown in FIG.
It has a pair of frame bodies 11, 12, and one of the frame bodies 12 is provided with a motor 13 that can rotate forward and backward. Gears 15 and 16 are fixed to a shaft 13a which is connected to the output shaft of the motor 13 and is pivotally supported by the two frame members 11 and 12, respectively. A gear 19 meshed with the gear 15 is provided at one end of a shaft 17 pivotally supported by the frame 12.
A sprocket 21 around which a chain 20 is wound is fixed to the other end of the shaft 17. The chain 20 includes a sprocket 23 pivotally supported on the frame 12 by a shaft 22.
In addition, a drive pin 25 having a free end facing inward and a flag 26 for position detection are provided at appropriate positions of the chain 20.

The photo interrupter sensors 27 and 2
9 are provided, respectively, and the sensor 27 detects that the drive pin 25 is at the back standby position by the flag 26,
The sensor 29 detects the drive pin 25 by the flag 26 at the front standby position shown in the figure. Rails 11a, 12a having a plurality of guide rollers 30 at the lower inside of the frames 11, 12
Each of the rails 12a is provided with a microswitch 31 for detecting that the cassette 3 has been inserted.

At both ends of a shaft 33 pivotally supported by the other frame 11, a gear 35 meshing with the gear 16 and a sprocket 36 similar to the sprocket 21 are fixed, respectively, and connected to the sprocket 36 by a chain 38. The sprocket 37 is pivotally supported on the frame 11 by a shaft 39. The sprocket 37 has a drive pin facing the drive pin 25.
25 are provided.

On the both sides of the front end of the cassette 3, there are formed L-shaped grooves 40 in side view, which engage with the drive pins 25. When the drive pins 25 are at the front standby position in FIG.
When the drive pin 25 is inserted into the transfer device 5, the drive pins 25 can enter from the opening 40 c of the groove 40.

As shown in FIG. 4, the apparatus main body 2 is provided with a paper presence detection mechanism (sheet presence detection means) A for detecting the presence or absence of the paper S in the cassette 3. The paper presence / absence detection mechanism A includes a detection lever 43 rotatably supported around a shaft 42 and a sensor 45. When the paper S is loaded in the cassette 3, the detection is performed. One end 43a of the lever 43 is placed on the upper surface of the sheet S by its own weight, and the other end 43b is in a state where the optical path of the sensor 45 is shielded. The front end of the middle plate 46 on which the paper S in the cassette 3 is placed is urged upward by a spring 47, and the urging force brings the paper S into contact with the separator 49.

When the sheet S in the cassette 3 runs out, one end 43a of the detection lever 43 falls into a notch 46a formed in the middle plate 46, and the detection lever 43 rotates counterclockwise about the shaft 42 in the figure. I do. By this rotation, the other end of the detection lever 43
43b is retracted from the sensor 45 and gives an OFF signal to notify the control section C (see FIG. 6) of the apparatus main body 2 that the paper S in the cassette 3 has run out. As shown in FIG. 6, the control unit C is connected with the motor 13, the sensors 27 and 29, the microswitch 31, the sensor 45, and an eject key 47 used when the cassette 3 is carried out. .

In the image forming apparatus configured as described above, when the sheets S are stacked on the cassette 3 and mounted on the apparatus main body 2, with respect to the approach direction of the opening 40c of the groove 40 of the cassette 3 (see FIG. 2). When the cassette 3 is inserted into the transfer device 5 in this state, the drive pin 25
Is inserted into the groove 40, and at the same time, the microswitch 31 is turned on by the bottom of the cassette 3.

The control unit C that has received the ON signal of the micro switch 31
The motor 13 is driven to rotate the drive pin 25 together with the chain 20. The rotation of the drive pin 25 causes the drive pin 25 to
The cassette 3 is moved in the direction of arrow E (see FIG. 2) and inserted into the transport device 5 by the linear movement of the drive pin 25 after that.

When the cassette 3 is transported to the back standby position, the chain
The flag 26 provided with 20 is detected by the sensor 27, and the control unit C that has received the detection signal stops the rotation of the motor 13, whereby the cassette 3 is mounted at a predetermined position in the apparatus main body 2.

When the cassette 3 is carried out (ejected), the eject key 47 shown in FIG. 6 is operated by the operator to input an eject signal to the control section C. Upon receiving this signal, the control section C reverses the motor 13 and causes the chain 20 to rotate. And the drive pin 25 is rotated in the opposite direction. The other wall surface 40b of the groove 40 is pressed by the drive pin 25 due to the reverse rotation and the movement of the drive pin 25 in the reverse direction, the cassette 3 is moved in the direction of arrow D in FIG. Then, the rotation of the motor 13 is stopped by a command from the control unit C. In this state, the cassette 3 is located at the front standby position, and the drive pins 25 are stopped in a state where the cassette 3 can be removed (see FIG. 1).

Next, when the paper S in the cassette 3 mounted in the apparatus main body 2 runs out during copying, the detection lever shown in FIG.
As described above, one end 43a of the sensor 43 falls into the notch 46a of the middle plate 46 and rotates counterclockwise in the drawing to turn off the sensor 45 and output a signal indicating no paper S (no sheet). The signal without the sheet S is input to the control unit C.
The automatic unloading of the cassette 3 by detecting the state of the absence of the sheet S, and the cassette 3 after the replenishment of the sheet S by the operator.
Will be described with reference to a control flowchart shown in FIG.

First, when the operator turns on the power, the sensor
27, the current position of the cassette 3 is checked (S1
01). In this case, since the cassette 3 is mounted on the apparatus main body 2, the drive pin 25 is at the back standby position and the sensor 27 is ON, it is checked whether the micro switch 31 is ON (S102). Since this is ON, it is checked whether the copy key (not shown) is pressed (S103).
If the copy key is not pressed, the eject key 47 is pressed to move the cassette 3 out of the machine (outside the main body 2).
The motor 13 is driven in the direction of unloading (the direction opposite to the arrow E).

After the copy key is pressed and the copying operation is started, the presence or absence of the sheet S in the cassette 3 is checked before the next copying is performed (S121). When there is no more paper S in the cassette 3, after confirming that the operation of the apparatus main body 2 is completed, the motor 13 for driving the cassette 3 is rotated in the discharge direction of the cassette 3 (S1).
07).

Next, it is checked that the sensor 29 is ON (S108), and the drive pin 25
Moves to the front standby position, the sensor 29 is turned on and the motor 13 is turned off (S109). Next, it is checked whether or not the micro switch 31 is ON (S110). If it is ON, the same check is continued until it is turned OFF. At this time, the operator confirms that the cassette 3 has stopped, and
And pull out the cassette 3 until the micro switch 31 is turned off.
Push it in until 31 turns on. Then, the micro switch 31
Is changed from ON to OFF and further changed from OFF to ON (S110) (S111), and the motor 13 is rotated in the loading direction of the cassette 3 (S113).

Next, when the sensor 27 is ON and the eject key 47
Is checked (S114) (S115). At this time,
The sensor 27 is OFF if the cassette 3 has not moved to the apparatus position (back standby position).
Is turned on (S116). This is ON unless the cassette 3 is removed by the operator before the drive pin 25 is engaged with the cassette 3. Therefore, it is checked whether the sensor 27 is ON and the eject key 47 is ON (S117). (S118) Since the eject key 47 is OFF, the processes from S114 and S115 are repeated.

Meanwhile, the cassette 3 moves to the mounting position and the sensor
Since the sensor 27 is ON, the sensor 27 is ON and the eject key 47 is OFF (S114) (S115), the motor 13 is turned OFF (S11).
9), the cassette 3 is in the mounted state. As described above, the sheet S is supplied by the operator.

On the other hand, as shown in the control flowchart of FIG. 3, the cassette 3 is pushed into the apparatus main body 2 and the micro switch 31 is turned on regardless of whether or not the paper S has been supplied (S110, 111). Motor for driving cassette
13 is rotated in the cassette 3 loading direction (S113). The subsequent operation is as described above, during which the operation of the motor 13 is controlled irrespective of the signal of the sheet S presence / absence detection means (sheet presence / absence detection mechanism A) in the cassette 3.

By performing such control, when there is no paper S to be replenished at the time when the cassette 3 has run out and the cassette 3 has run out, the cassette 3 is left in the unloaded state. The cassette 3 is once carried into the apparatus main body 2, and the cassette 3 can be taken out by the eject key 47 and replenished with the paper S when necessary.

Although the above-described embodiment is an example in which the front loading apparatus is applied to a copying machine, the present invention is not limited to this, and it is needless to say that the front loading apparatus can be applied to other image forming apparatuses such as a printer and a facsimile. However, the present invention is not limited to this and can be applied to other loading mechanisms.

(G) Effects of the Invention As described above, according to the present invention, when the absence of sheets in the cassette is detected by the sheet presence / absence detecting means, the cassette is carried out of the apparatus main body, and the carried out empty space is removed. When the cassette is pushed into the apparatus main body in a state where the cassette is not replenished with sheets, the cassette unloading control means controls the drive means so as not to operate, so, for example, when there is no sheet to the empty cassette unloaded. By pushing an empty cassette into the apparatus main body, it is possible to eliminate such a problem that the empty cassette projects from the apparatus main body and hinders the operator.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a main part of an image forming apparatus of the present invention, FIG. 2 is a vertical sectional side view of a copying machine (image forming apparatus) to which the present invention is applied, and FIG. FIG. 4 is a control flowchart showing one embodiment of control of the auto-loading mechanism of the image forming apparatus of the present invention. FIG. 4 is a longitudinal side view of a paper presence / absence detection mechanism in a cassette. FIG. It is a block diagram of a control part concerning the invention. S: sheet (paper), A: paper presence / absence detection mechanism (sheet presence / absence detection means), C: control unit (cassette unloading control means), 2: apparatus main body, 3: cassette, 13: motor ( Driving means), 27, 29 ... sensor, 31 ... micro switch.

Claims (1)

(57) [Claims] 1. A cassette for loading sheets, a main body of the apparatus for feeding paper by incorporating the cassette, and a cassette for moving the cassette in and out of the main body of the apparatus and provided in the main body of the apparatus. Driven means, sheet presence detection means for detecting the presence or absence of sheets in the cassette,
In the image forming apparatus having a sheet, by the sheet presence detection signal of the sheet presence detection means,
A cassette unloading control unit for controlling the operation of the driving unit in a direction in which the cassette is unloaded from the apparatus main body, wherein the cassette unloading control unit operates the driving unit after the image forming operation of the apparatus main body is completed. When the cassette is returned into the apparatus main body after controlling and operating the driving unit, the cassette unloading operation by the driving unit is stopped regardless of the sheet absence detection signal of the sheet presence / absence detecting unit. An image forming apparatus characterized in that the image forming apparatus is controlled as follows.