JPH05165267A - Image forming device - Google Patents

Abstract

PURPOSE:To provide a small-sized, inexpensitive image forming device by reducing the number of detection switches to be used. CONSTITUTION:A pressing projection 25 is pressed against the energizing force of a first spring 54 to separate a push lever 53 from a striker lever 52. When a fixing unit 20 is opened, the pressing projection 25 is separated so that the striker lever 52 is separated from an interlocking switch 51 and the switch 51 is turned on. When the cover 30 of an original reading part is opened, a second spring 55 fixed to a spring fixing part 36 is separated so that the striker lever 52 is rotated by means of the energizing force Fs of a spring in the interlocking switch 51 and the interlocking switch 51 is turned on.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a laser printer or a plain paper copying machine, and more particularly to an image forming apparatus having a mechanism for detecting the state of constituent members.

[0002]

2. Description of the Related Art An image forming apparatus exposes an internal mechanism by opening to replace a consumable member, a maintenance cover for performing maintenance of each part, and an external cover when optically reading a document. It is equipped with a document reading section cover that blocks light, a detachable paper feed cassette that stores recording paper inside, and the like. Further, in an apparatus that forms an image by an electrophotographic method, a developing unit that stores toner for forming a toner image is arranged.

In the image forming apparatus having the above-mentioned structure, in order to ensure the safety of the operator or to perform the image formation in a normal state, the operating state of each member,
Alternatively, the remaining amount of toner is detected by an interlock mechanism including an interlock switch that is a detection switch, and when the device does not meet preset conditions, the operation of the device is forcibly stopped. ..

[0004]

However, in recent years, image forming apparatuses have been reduced in size and cost, and it is required to simplify the apparatus configuration and reduce the number of parts. In the image forming apparatus having the above configuration, when the interlock switch is arranged for each member such as the maintenance cover, the document reading unit cover, the sheet feeding cassette, and the developing unit, the number of interlock switches increases,
There are problems that the cost cannot be reduced and the device cannot be downsized.

SUMMARY OF THE INVENTION An object of the present invention is to provide a small-sized and low-cost image forming apparatus in which the number of detection switches used is reduced in order to solve the above problems.

[0006]

In order to solve the above-mentioned problems, the present invention comprises an openable and closable fixing unit cover arranged in a housing and an openable and closable original reading section cover arranged in the housing. In an image forming apparatus provided with the detection unit, a detection switch for detecting whether the fixing unit cover and the document reading unit cover are opened or closed, and an operating position for operating the detection switch in conjunction with opening of the fixing unit cover are provided. It is characterized in that it is provided with an operating lever that moves and a moving lever that moves the operating lever to the operating position in conjunction with opening of the original reading unit cover.

Further, the opening / closing detection of the fixing unit cover is continued after the image forming apparatus equipped with the opening / closing fixing unit cover arranged in the casing and the detachable paper feeding cassette arranged in the casing. And a detection switch for detecting attachment / detachment of the paper feed cassette, an operation lever that moves to an operation position that operates the detection switch in conjunction with opening of the fixing unit cover, and the paper feed cassette is pulled out. In particular, a moving lever for moving the operating lever to the operating position is provided.

Further, in an image forming apparatus equipped with an openable / closable original reading unit cover arranged in a housing and an agitator which rotates in a developing unit to agitate toner, the opening / closing detection of the reading unit cover and the above-mentioned A detection switch for detecting the remaining amount of toner in the developing unit; a first operation lever that moves to an operation position for operating the detection switch in conjunction with opening of the original reading unit cover; A second actuating lever that moves to the actuating position in association with the rotation of the agitator when the remaining amount of toner becomes less than or equal to a predetermined amount.

Further, in an image forming apparatus equipped with a detachable paper feed cassette disposed in a housing and an agitator which rotates in a developing unit to agitate toner, the attachment / detachment detection of the paper feed cassette and the development are performed. A detection switch for detecting the remaining amount of toner in the unit, a first operation lever that moves to an operation position that operates the detection switch in association with the pulling out of the sheet feeding cassette, and the remaining toner And a second actuating lever that moves to the actuating position in association with the rotation of the agitator when the amount becomes equal to or less than a predetermined amount.

Further, the drive mechanism of the second actuating lever is fixed to a first cam integrally formed with a drive gear for transmitting a rotational drive force to the agitator, and coaxially with the first cam. In addition, only when the second cam having a sliding surface of the same shape as the first cam and the remaining amount of the toner are less than or equal to a predetermined amount, the first cam is used to cope with the reduction of the driving load of the agitator. By contacting the first cam and the second cam with the actuator that makes the phase of the cam of the second cam coincide with the phase of the second cam, the second operating lever passes through the operating position when the phases coincide. For this reason, the second actuating lever is configured by a driven lever that transmits the swinging motion.

[0011]

According to the above means, the operating lever that moves to the operating position of the detection switch in conjunction with the opening of the fixing unit cover and the operating lever in conjunction with the opening of the document reading section cover are operated. The detection lever output corresponding to the operation of the fixing unit cover and the image reading unit cover can be output by the single detection switch by the moving lever that moves the operation position.

Also, an operation lever that moves to the operation position of the detection switch in conjunction with the opening of the fixing unit cover and a movement that moves the operation lever to the operation position in association with the withdrawal of the sheet cassette. With the lever, the detection signal output corresponding to the operation of the fixing unit cover and the sheet feeding cassette can be output by a single detection switch.

Further, the first operation lever which moves to the operation position of the detection switch in conjunction with the opening of the document reading section cover and the rotation of the agitator when the remaining amount of toner falls below a predetermined amount. Second to move to the operating position
With the operation lever of 1, the detection signal output corresponding to the operation of the document reading unit cover and the remaining toner amount can be output by a single detection switch.

The first operating lever which moves to the operating position of the detection switch in conjunction with the withdrawal of the paper feed cassette and the rotation of the agitator when the remaining amount of toner falls below a predetermined amount. With the second operating lever that moves to the operating position, a single detection switch can output a detection signal output corresponding to the operation of the paper feed cassette and the remaining amount of toner.

Further, a first cam integrally formed with the drive gear of the agitator, and fixed coaxially with the first cam,
Moreover, a second cam having a sliding surface of the same shape as the first cam, and an actuator for matching the phase of the first cam with the second cam only when the remaining amount of toner is less than or equal to a predetermined amount. , A detection signal synchronized with the rotation of the agitator is generated by the drive mechanism of the second actuating lever that is in contact with the first cam and the second cam and that has a driven lever that transmits a swinging motion when the phases match. , It can be output by the detection switch.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing the outline of a copying apparatus which is an embodiment of the present invention.

Reference numeral 1 is a main body portion, 20 is a fixing unit, 30 is a document reading portion cover, and 40 is a paper feed cassette. Fixing unit
By releasing the locking mechanism (not shown), 20
It is configured to be rotatable in the direction of arrow A about the rotation shaft 21, and the internal mechanism of the main body 1 is exposed in the rotated state. By rotating the fixing unit 20, the operator can perform maintenance such as replacement of the CTM (cleaning toner magazine) 2. Further, the document reading unit cover 30 is configured to be rotatable in the direction of arrow B about the rotation shaft 31, so that the operator can read the document reading unit cover.
Rotate 30 to remove jammed documents and contact glass 3
Can be cleaned. Also, the paper feed cassette 40 is
By pulling out in the direction of the arrow C, it is possible to separate from the main body unit 1, and the operator pulls out the paper feed cassette 40 to supply the recording paper 41, and the recording papers of other sizes are stored. It can be replaced with the paper feed cassette 40.

The original document (not shown) to be copied is inserted into the insertion port 32 of the original document reading cover and is conveyed at a constant speed by the conveying roller pair 33, and at the position opposite to the contact glass 34, it is emitted from the fluorescent lamp 35. It is irradiated with light. The reflected light R from the document enters the line sensor 37 via the mirror 36 and is detected.

A detection signal of the line sensor 37 is converted into image information in a control unit (not shown). Although detailed description is omitted, an electrostatic latent image based on image information is formed on the photoconductor belt 3 by a known electrophotographic method.
The electrostatic latent image is developed as a toner image by the developing unit 4 in which the developing roller 4c is pressed against the photosensitive belt 3. On the other hand, on the recording paper 41 conveyed from the paper feed cassette 40 in synchronization with the position of the toner image on the photosensitive belt 3,
The toner image is electrostatically transferred at the transfer position. The recording paper on which the toner image is transferred is conveyed to the fixing unit 20,
The toner image is fixed by being conveyed while being pressed against each other by a roller pair including a heating roller 22 and a pressure roller 23. The recording paper 41 on which the toner image has been fixed is discharged to the paper discharge tray 24.

FIG. 1 is a block diagram showing an example of an interlock mechanism for the fixing unit and the document reading section cover of this embodiment.

The interlock mechanism is a push button 51.
It is composed of an interlock switch 51 having a, a striker lever 52, a push lever 53, and the like. The interlock switch 51 applies an urging force F _S in the protruding direction to the push button 51a by a built-in spring.

FIG. 3 is an explanatory view of the interlock mechanism of FIG.

At the mounting position, the pressing projection 25 formed on the fixing unit 20 stops the push lever 53 at a position slightly separated from the striker lever 52 against the biasing force F1 of the first spring 54. When the fixing unit 20 for internal inspection or the like is opened, the pressing protrusion 25 separates from the push lever 53, so that the push lever 53 is counteracted about the rotating shaft 53a by the urging force F1 of the first spring 54. By rotating the striker lever 52 in a clockwise direction and contacting the striker lever 52, a force for rotating the striker lever in a counterclockwise direction is applied. At this time, the striker lever
A biasing force F2 in the clockwise direction is applied to 52 by the second spring 55, but the push lever 53 rotates the striker lever 52 in the counterclockwise direction by a certain angle against the biasing force F2. When the striker lever 52 is rotated counterclockwise, the push button 51a of the interlock switch 51 projects so that the contact is turned on and the interlock signal is output to a control unit (not shown).

A second spring 55 is fixed to the spring fixing portion 36 of the document reading section cover 30, and the document reading section cover 30 is in a fixed position at the striker lever 52.
The urging force F2 of the second spring 55 is applied to. The striker lever 52 presses the push button 51a of the interlock switch 51 by the urging force F2 and holds the striker lever 52 in a pressed position where an interlock signal is not output. When the original reading section cover 30 is opened for maintenance,
Since the second spring 55 is separated from the striker lever 52, the urging force F2 is removed. The striker lever 52 can be rotated counterclockwise by a slight external force when the urging force F2 is removed. For this reason,
The interlock switch 51 rotates the striker lever 52 to project the push button 51a by the biasing force F _S of the built-in spring, and outputs the interlock signal.

In the interlock mechanism having the above structure, an interlock signal is output when one or both of the fixing unit 20 and the document reading section cover 30 are opened, so that the apparatus operates in an incomplete state. The fixing unit 20 and the document reading section cover can be prevented.
Since the position of 30 and 30 can be detected by one interlock switch 51 and an interlock signal can be output, it is possible to reduce the number of interlock switches to be used, so that the cost and size of the device can be reduced. Becomes

FIG. 4 is a block diagram showing an example of an interlock mechanism for the fixing unit and the sheet feeding cassette of this embodiment.

The interlock mechanism has a push button 61.
It is composed of an interlock switch 61 having a, a striker lever 62, a push lever 63, and the like. Interlock switch 61, by the biasing force F _S of the built-in spring, and imparting a biasing force F _S in the projecting direction to the push button 61a.

The interlock mechanism shown in FIG. 4 has the same structure as the interlock mechanism described with reference to FIGS. 1 and 2. When the fixing unit 20 is opened, the push lever 63 causes the urging force F1 of the first spring 64.
The striker lever 62 is pressed by being rotated clockwise by the. By being pushed by the push lever 63, the striker lever 62 rotates around the rotation shaft 62a and separates from the push button 61a of the interlock switch 61. At this time, the interlock switch 6
The first push button 61a projects by the biasing force F _S and outputs an interlock signal.

Further, when the paper feed cassette 40 is pulled out in the direction of arrow C, the second spring 65 fixed to the spring fixing portion 45 is separated from the striker lever 62.
The striker lever 62 from which the biasing force F2 of the second spring 65 has been removed allows the striker lever 62 to rotate in the clockwise direction with a slight external force. Therefore, the interlock switch 61 causes the push button 61a to project by the biasing force F _S and outputs an interlock signal.

In the interlock mechanism having the above structure, the interlock signal is output when one or both of the fixing unit 20 and the paper feed cassette 40 is opened or pulled out, so that the apparatus is incomplete. It is possible to prevent the interlock switch from operating in such a state that the fixing unit 20 and the sheet feeding cassette 40 are position-detected by one interlock switch 61 and output an interlock signal. Since the number can be reduced, the cost of the device can be reduced and the device can be downsized.

FIG. 5 is a block diagram showing an example of an interlock mechanism for the remaining amount of toner in the document reading section cover and the developing unit of this embodiment.

The interlock mechanism is composed of an interlock switch 71, a first striker lever 72, a second striker lever 73, a drive mechanism for a second striker lever 73, which will be described later, and the like.

The pressing projection 37 formed on the document reading section cover 30 at a fixed position presses the first striker lever 72 against the counterclockwise rotational force generated by the urging force F1 of the first spring 74. It is held in place.
When the document reading section cover 30 is opened,
37 is separated from the first striker lever 72. The first striker lever 72 is released from the restraining force of the pressing protrusion 37, so that the first spring 7 is rotated about the rotation shaft 72a.
It is rotated counterclockwise by a predetermined angle by the urging force F1 of 4. At this time, the first striker lever 72 moves its tip to the detection position of the interlock switch 71.
Interlock switch 71 is the first striker lever
Detects that 72 is at the detection position and outputs an interlock signal.

The interlock switch 71 is formed in a substantially U shape, and is composed of a proximity switch capable of detecting an object in a non-contact state when there is an object between the opposing plates.

FIG. 6 is an exploded perspective view showing the structure of the drive mechanism of the second striker lever shown in FIG. Also,
7 and 8 are explanatory views showing the operating state of the drive mechanism.

The drive mechanism of the second striker lever 73 is
The drive gear portion 11a and the cam portion 11b are integrally formed, and includes a cam drum 11, a cam plate 12 that is in close contact with the cam drum 11, and a driven lever 13 that is coaxially fixed to the second striker lever 73 by a rotating shaft 73a. ing.

The cam drum 11 is provided with a through hole 11c through which the drive shaft 4b of the agitator 4a is loosely formed, and a hollow portion 11d is formed inside the cam portion 11b.
A pin 11e for hooking one end of the spring 14 is provided at a value. In addition, the cam plate 12 has a spring 14
A pin 12a for hooking the other end of the is set. The cam drum 11 and the cam plate 12 are assembled in a state where the pin 11e of the cam drum 11 and the pin 12a of the cam plate 12 are hooked at the ends of the springs 14 in the air discharge portion 11d. It is fixed to the end of the drive shaft 4b. Rotational driving force is transmitted to the drive gear portion 11a by a gear train (not shown).
The rotational driving force transmitted to 11a is transmitted to the drive shaft 4b via the cam plate 11 connected by the spring 14.

Here, when the agitator 4a is rotated in a state where the developing unit 4 contains a sufficient amount of toner, the spring 14 connecting the cam drum 11 and the cam plate 12 expands due to the resistance of the toner. Is configured. Further, when the spring 14 is extended, the cam portion 11b of the cam drum 11 and the cam plate 12 are
Further, the circular groove 11f and the circular groove 12b, which are formed in the same shape, are configured so that their phases do not match.

FIG. 7 shows a state in which the circular groove 11f of the cam portion 11b and the circular groove 12b of the cam plate 12 are out of phase with each other, and the outer peripheral portions of both members of the cam portion 11b and the cam plate 12 are shown. In addition, the second spring 75 is pressed by the urging force F2. The driven roller 13a of the driven lever 13 always keeps the cam portion 11b.
And the cam plate 12 slide on one circumferential surface. Therefore, the driven lever 13 is held in a fixed position without performing a driven motion.

Further, when the agitator 4a is rotated in a state where the remaining amount of toner in the developing unit 4 is less than or equal to a predetermined amount, the resistance force for agitating the toner decreases, so that it is necessary to rotate the agitator 4a. The rotational driving force is also reduced. At this time, the spring 14 contracts as compared with the state where the toner is sufficiently stored.
The phase of the circular groove 11f of 11b and the circular groove 12b of the cam plate 12 are configured to match each other.

FIG. 8 shows a state in which the circular groove 11f of the cam portion 11b and the circular groove 11b of the cam plate 12 are in phase with each other, and the driven lever which is in pressure contact with the cam portion 11b and the cam plate 12 is shown. Since the driven roller 13a of 13 slides along the circular grooves 11f and 12b, the driven lever 13 makes a reciprocating swing motion of a constant cycle and a constant stroke. The second striker lever 73 fixed coaxially with the driven lever 13 also performs a reciprocating swing motion, and the tip of the striker lever 73 passes the detection position of the interlock switch 71 at a constant cycle, and To be detected. Therefore, the interlock switch 71 outputs an interlock signal of a constant cycle to a control unit (not shown).

In the interlock mechanism having the above-described structure, the interlock signal is output at least when the original reading unit cover 30 is opened or when the toner in the developing unit 4 becomes less than the predetermined amount. ,
It is possible to prevent the apparatus from operating in an incomplete state, and it is possible to output the interlock signal by opening the document reading section cover 30 and the interlock signal by decreasing the toner amount by the same interlock switch 71. Since it is possible to reduce the number of interlock switches to be used, the cost and size of the device can be reduced, and the interlock signals are output from the interlock switch 71 in different output patterns. The control unit or the like can determine the cause of the interlock, and the alarm display to the operator or the like can be changed depending on the cause.

FIG. 9 is a block diagram showing the interlock mechanism for the remaining amount of toner in the paper feed cassette and the developing unit of this embodiment.

In FIG. 9, members corresponding to those described with reference to FIGS. 5, 6, 7 and 8 are designated by the same reference numerals, and the description thereof will be omitted or simplified.

When the paper feeding cassette 40 is in the home position, the pressing protrusion 46 of the paper feeding cassette 40 is not moved to the first striker lever 72.
To a position not detected by the interlock switch 71. Further, when the paper feed cassette 40 is pulled out, the pressing protrusion 46 is separated from the first striker lever 72. The first striker lever 72 released from the restraint of the pressing protrusion 46 rotates clockwise and is detected by the interlock switch 71.

Further, as described above, when the remaining amount of toner in the developing unit 4 becomes less than a certain amount, the second striker lever 73 makes a reciprocating swing motion and is detected by the interlock switch 71 at a certain period.

In the interlock mechanism having the above structure, the interlock signal is output at least when the paper feed cassette 40 is pulled out or the toner in the developing unit 4 becomes less than a certain amount. Can be prevented from operating in an incomplete state. further,
The interlock signal due to the removal of the paper feed cassette 40 and the interlock signal due to the decrease of toner can be output by the same interlock switch 71, so that the number of interlock switches to be used can be reduced. Cost reduction and downsizing are possible,
Further, since each interlock signal is output from the interlock switch 71 with a different output pattern, it is possible to determine the cause of the interlock by the control unit and the like, and the alarm display to the operator and the like can also be changed depending on the cause. It becomes possible.

[0049]

As described above, according to the present invention,
Detection mechanism for opening of the fixing unit cover or opening of the document reading section cover, detection mechanism for opening of the fixing unit cover, or removal of the paper feeding cassette, removal of the paper feeding cassette, or detection of toner in the developing unit. Since the detection mechanism for reduction can output the detection signal output corresponding to the state of two members by a single detection switch, the number of detection switches used for controlling the device can be reduced. Therefore, the cost and size of the apparatus can be reduced, and a signal corresponding to the toner decrease in the developing unit is caused to cause the second actuating lever to perform a swing motion in accordance with the drive load of the agitator. The drive mechanism allows the detection switch to output a detection signal in synchronization with the rotation of the agitator. Because, by the different output patterns from the detection signal state is detected and the output of the other members, it is possible to provide an image forming apparatus capable of determining an interlock caused by, for example, the control unit or the like.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of an interlock mechanism for a fixing unit and a document reading cover according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing an outline of a copying apparatus which is an example of the present embodiment.

3 is an explanatory view of an interlock mechanism shown in FIG. 1. FIG.

FIG. 4 is a configuration diagram illustrating an example of an interlock mechanism for the fixing unit and the sheet feeding cassette according to the present exemplary embodiment.

FIG. 5 is a configuration diagram showing an example of an interlock mechanism with respect to the remaining amount of toner of the document reading unit cover and the developing unit of the present embodiment.

6 is an exploded perspective view showing a configuration of a drive mechanism of the second striker lever shown in FIG.

7 and 8 are explanatory diagrams showing an operating state of the drive mechanism shown in FIG. 6.

FIG. 9 is a configuration diagram showing an example of an interlock mechanism with respect to the remaining amount of toner in the sheet feeding cassette and the developing unit of the present embodiment.

[Explanation of symbols]

4 ... Developing unit, 4a ... Agitator, 4b ... Drive shaft, 11 ... Cam drum, 12 ... Cam plate, 20
... Fusing unit, 30 ... Original reading section cover, 40 ... Paper feed cassette, 51,61,71 ... Interlock switch,
52,62 ... Striker lever, 53,63 ... Push lever, 72 ... First striker lever, 73 ... Second striker lever.

Claims (5)

[Claims] 1. An image forming apparatus including an openable / closable fixing unit cover arranged in a housing and an openable / closable original reading unit cover arranged in the housing, wherein the fixing unit cover and the original reading are provided. Detection switch for detecting the opening / closing of the unit cover, an operation lever for moving the detection switch in conjunction with the opening of the fixing unit cover, and the document reading unit cover are opened. An image forming apparatus comprising: a moving lever that moves the operating lever to the operating device in conjunction with the above. 2. An image forming apparatus comprising an openable / closable fixing unit cover arranged in a casing and a detachable paper feeding cassette arranged in the casing, the opening / closing detection of the fixing unit cover and the A detection switch for detecting the attachment / detachment of the paper feed cassette, an operation lever for moving the detection switch in conjunction with the opening of the fixing unit cover, and a paper feed cassette removal An image forming apparatus comprising: a moving lever that moves the operating lever to the operating position in conjunction with each other. 3. An image forming apparatus comprising an openable / closable original document reading unit cover arranged in a housing and an agitator that rotates in a developing unit to agitate toner, and the opening / closing detection of the reading unit cover and the agitator. A detection switch for detecting the remaining amount of toner in the developing unit, and a first operation lever that moves to an operation position that operates the detection switch in conjunction with opening of the document reading unit cover,
An image forming apparatus comprising: a second operation lever that moves to the operation position in association with rotation of the agitator when the remaining amount of the toner becomes less than or equal to a predetermined amount. 4. An image forming apparatus equipped with a detachable paper feed cassette disposed in a housing, and an agitator that rotates in a developing unit to agitate toner. A detection switch for detecting the remaining amount of toner in the unit, a first operation lever that moves to an operation position that operates the detection switch in association with the pulling out of the sheet feeding cassette, and the remaining toner An image forming apparatus, comprising: a second operating lever that moves to the operating position in association with rotation of the agitator when the amount becomes equal to or less than a predetermined amount. 5. A first cam integrally formed with a drive gear for transmitting a rotational driving force to the agitator, the drive mechanism for the second actuating lever being fixed coaxially with the first cam. In addition, only when the second cam having a sliding surface of the same shape as the first cam and the remaining amount of the toner are less than or equal to a predetermined amount, the first cam is used to cope with the reduction of the driving load of the agitator. By contacting the first cam and the second cam with the actuator that makes the phase of the cam of the second cam coincide with the phase of the second cam, the second operating lever passes through the operating position when the phases coincide. 6. The image forming apparatus according to claim 4, further comprising a driven lever for transmitting the swinging movement to the second actuating lever.