JPH10143028A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of accurately detecting the amount of toner remaining in an image forming unit. SOLUTION: When the image forming unit is properly installed in a main body base 11 (device main body), a residual toner detecting sensor 91 is moved to an installed position. On the other hand, when the image forming unit is improperly installed in the main body base 11 (device main body) or removed therefrom, the sensor 91 is moved to a noninstalled position. Further, a sensor supporting member 922 is turned according to the movement of the residual toner detecting sensor 91 and the other end 922b of the sensor supporting member 922 pushes or leaves the working part 94a of a presence detecting sensor 94 to detect the fact that the image forming unit is properly installed in the main body base 11 or not. Then, the residual toner detecting sensor 91 detects the amount of the toner remaining in the image forming unit, on the assumption that it is judged that the image forming unit is properly installed in the main body base 11 by the presence detecting sensor 94.

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 (laser printer, copying machine) in which an image forming unit for developing an electrostatic latent image formed on a photosensitive drum with toner is detachably attached to an apparatus main body. Machine, facsimile machine, etc.), in particular, a toner remaining detection sensor for detecting the amount of toner remaining in the image forming unit, and a presence / absence detecting sensor for detecting whether or not the image forming unit is attached to the apparatus main body. Related to the arrangement structure.

[0002]

2. Description of the Related Art In an image forming apparatus of this kind, for example, a laser printer, a copying machine, a facsimile machine, etc., an electrostatic latent image is formed by irradiating a photosensitive drum with a laser beam based on given image information. Further, after the toner is developed by the developing unit, the image is transferred onto the recording paper. Therefore, if the image forming apparatus is operated without the image forming unit in which the photosensitive drum and the developing unit are integrated in the apparatus main body, the laser beam that should be irradiated on the photosensitive drum is applied to the photosensitive drum. There is a possibility that the light is not irradiated and enters the eyes of the user and damages the eyes of the user. Therefore, conventionally, a presence / absence detection sensor for detecting whether or not the image forming unit is mounted is attached to the apparatus main body side, and when it is determined that the image forming unit is not mounted, a laser beam is used. Is prohibited from forming an electrostatic latent image.

Further, in order to develop the electrostatic latent image with toner, it is necessary that a certain amount or more of toner remains in the developing section, and it is possible to prevent recording paper from passing when the toner is insufficient. To this end, a residual toner detection sensor for detecting the residual amount of toner in the developing unit constituting the image forming unit is provided on the apparatus main body side.

[0004]

The presence / absence detection sensor of the above two types of sensors is intended to detect whether or not the image forming unit is mounted on the apparatus main body. Only low detection accuracy is required. In other words, for the presence / absence detection sensor, it can be said that the tolerance of mounting accuracy of the image forming unit to the apparatus main body is relatively large. Therefore, a relatively low detection accuracy sensor such as a contact switch is used as the presence / absence detection sensor. Even if the imaging unit is slightly deviated from the proper mounting position due to, for example, oblique insertion, image formation is not performed. The attachment of the unit to the apparatus main body was detected by the presence / absence detection sensor.

On the other hand, since the toner residual detection sensor needs to accurately detect the amount of toner remaining in the image forming unit, a sensitive sensor such as a photo interrupter has been conventionally used as the toner residual detection sensor. Even if the mounting state of the image unit to the apparatus main body is slightly deviated from an appropriate mounting position, the amount of toner remaining in the inserted image forming unit cannot be accurately detected.

As described above, in the conventional image forming apparatus, sensors having different tolerances regarding the mounting accuracy of the image forming unit to the apparatus main body are independent of each other, and furthermore, the sensors are attached to the apparatus main body without any relation. As described above, despite the fact that the image forming unit is obliquely inserted and deviated from a proper mounting position as described above, the presence / absence detection sensor detects that the image forming unit is mounted on the apparatus main body, and ,
As described above, as a result of detecting the amount of toner while being deviated from the proper mounting position, there is a problem that the residual amount of toner is erroneously detected.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has a sensor for detecting whether or not the image forming unit is attached to the apparatus main body, and a method for detecting the amount of toner remaining in the image forming unit. An object of the present invention is to provide an image forming apparatus capable of accurately detecting the amount of residual toner in an image forming unit by relating the arrangement relationship with a detection sensor.

[0008]

According to the first aspect of the present invention, an image forming unit for developing an electrostatic latent image formed on a photosensitive drum with toner is detachably mountable to an apparatus main body. The amount of toner remaining in the image forming unit is detected by a toner remaining detection sensor provided on the side of the image forming unit, and the image forming unit is mounted on the apparatus main body by a presence / absence detecting sensor provided on the apparatus main body side. In order to achieve the above object, the image forming apparatus detects whether or not the toner remaining detection sensor has a mounting position and a non-mounting position corresponding to a mounting state of the image forming unit to the apparatus main body. And whether the presence / absence detection sensor is mounted on the apparatus main body according to the position of the toner remaining detection sensor. It is configured to detect.

According to the present invention, the residual toner detection sensor is
The imaging unit moves to the mounting position when it is properly mounted on the main body of the apparatus, whereas it moves when the imaging unit is improperly mounted on the main body or is removed from the main body of the apparatus. Move to the mounting position. Then, based on the movement of the toner remaining detection sensor, the presence / absence detection sensor accurately detects whether or not the image forming unit is properly mounted, not limited to whether or not the image forming unit is mounted on the apparatus main body.

The invention according to claim 2 further comprises an urging means for urging the residual toner detection sensor toward the non-mounting position.

In the present invention, the urging means urges the toner residual detection sensor toward the non-mounting position, and when the properly mounted image forming unit is removed from the apparatus main body, the urging force causes the toner residual detection sensor to be urged. Moves to the non-mounting position side.

Preferably, the detection result by the toner remaining detection sensor is determined to be valid only when the mounting of the image forming unit to the apparatus main body is detected by the presence / absence detection sensor. The amount of toner remaining in the image forming unit is detected.

In the present invention, the amount of residual toner in the image forming unit is detected by the toner residual detecting sensor on the assumption that the image forming unit is determined to be properly mounted by the presence / absence detecting sensor. The conventional problem of detecting the amount of residual toner while being improperly attached to the apparatus main body is prevented.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an image forming apparatus according to an embodiment of the present invention; .

FIG. 1 is an external perspective view showing one embodiment of an image forming apparatus according to the present invention. Also, FIG.
FIG. 2 is a side view of the image forming apparatus of FIG. 1. This image forming apparatus is a multifunction peripheral having both a facsimile function and a copying function.

This image forming apparatus, as shown in FIG.
A frame structure 10 including a main body base 11 and an upper frame 12 is provided. In this frame structure 10, a bearing portion 111 is provided so as to protrude upward above a main body base 11 serving as an apparatus main body and on the back side (the left-hand side in the drawing). A rotation shaft 121 provided on the motor 12 is rotatably inserted. That is, in this embodiment, the upper frame 12 is
A so-called shell-type structure that can be opened and closed with respect to the device 1 is adopted. It is configured such that the image unit 20 can be inserted or taken out. Further, the recording paper in the JAM state inside the apparatus can be easily taken out. The image forming unit 20 has a conventionally well-known configuration except that the image forming unit 20 is detachably mounted inside the main body base 11. That is, an original image read by a contact image scanner or an image transmitted from a facsimile machine outside the apparatus is exposed to a photosensitive drum to form an electrostatic latent image of the image as described later, and The toner image is developed by a developing unit provided along the peripheral surface of the body drum, and the toner image is transferred by a transfer roller to a recording paper conveyed from a recording paper insertion tray as described later.

On the upper frame 12, as shown in FIG.
An automatic document feed unit 30 that reads an image of a document with a contact image sensor while automatically feeding the document is attached. The automatic document feeder unit 30 is connected to a document feeder housing (hereinafter simply referred to as “housing”) 31 directly attached to the upper frame 12, and connected to an end 311 on the rear side of the housing 31 by an arrow in FIG. A document feed guide (hereinafter, simply referred to as a “guide”) 32 rotatable with respect to the housing 31 in the direction α. Normally, the guide 32 rotates in the direction of the arrow (+ α) due to its own weight, opposes the housing 31 in proximity, and when the two document conveying rollers 312 and 313 disposed on the upper surface side of the housing 31 and the guide 321 rotate, While the original inserted in the original insertion tray 40 is sandwiched between the original transport rollers 312, 313, and 321, the original transport path OP indicated by a dashed line in FIG.
Along the front of the device. In this embodiment, the original transport rollers 312, 313, and 321 are driven to rotate, but these original transport rollers 312, 31
The document can also be conveyed by driving at least one of the rollers 3 and 321 to rotate and driving another document conveying roller.

A contact type image sensor 33 is mounted on the front side of the housing 31 so that the image of the original conveyed as described above is extended by one line extending in a direction perpendicular to the plane of FIG. Each time the document is read, the whole image of the document can be read when the document passes through the contact image sensor 33.

Returning to FIGS. 1 and 2, the description will be continued. In this image forming apparatus, the operation cover 51 is configured to cover the automatic document transport unit 30 configured as described above from above.
Further, a plurality of switches 52 such as a numeric key switch and a start button, and a display unit 53 for displaying a telephone number of a facsimile transmission destination and an operation state of the apparatus are attached to the front side of the operation cover 51. Thus, the operation unit 50 is configured. For this reason, the operator can perform a facsimile process and a copy process by pressing an appropriate switch 52 as needed, and can confirm an operation based on the display contents on the display unit 53.

A recording paper insertion tray 60 for inserting recording paper is mounted on the upper cover 12 side.
The recording paper inserted into the recording paper insertion tray 60 is shown in FIG.
Are transported along the recording paper transport path RP indicated by the two-dot chain line. That is, the recording paper is conveyed inside the apparatus, and after the image is recorded by the image forming unit 20 based on the original image read as described above and the image information transmitted from outside the apparatus, the recording paper is Conveyed.

The original and recording paper conveyed to the front side of the apparatus as described above are discharged from the front side of the apparatus to a tray unit 70 mounted toward the main body base 11. The tray unit 70 includes a tray frame 71 detachable from the main body base 11 of FIG.
And trays 72 and 73 which can be inserted and removed in two stages. In the image forming apparatus according to this embodiment, the upper tray 72 is used as a document discharge tray, while the lower tray 73 is used as a recording paper discharge tray.

It should be noted that on the outer peripheral side of the frame structure 10,
A plurality of covers 81 and 82 are attached to protect the inside of the apparatus.

FIG. 5 shows an image forming unit with a main body base 11.
FIG. 3 is a partial plan view in a state where an image forming unit 20 is removed from (apparatus main body). FIG. 6 is a cross-sectional view taken along the line AA of FIG. 5, and the illustration of the image forming unit 20 is omitted in FIG.
While FIG. 2B shows a case where the device is improperly mounted or is detached from the main body base 11, FIG.
This shows a case where the image forming unit 20 is properly mounted on the main body base 11. The details will be described below with reference to these drawings.

Reference numeral 112 in these figures denotes a support member for supporting the image forming unit 20 in the main body base 11.
Is attached. In addition, a part of the support member 112 includes
An opening 113 is provided, and the remaining toner detection sensor 91 can freely move in and out of the opening 113. That is, the residual toner detection sensor 91 is
6 (a) and 6 (b) according to the mounting state of the image forming unit 20 by the sensor mounting mechanism 92 provided on the lower side of FIG.
It is possible to reciprocate between the positions shown in FIG. This will be described in detail below.

The sensor mounting mechanism 92 includes a support member 11
2, the projection 921 extending downward from the curved bottom 112a side.
And a sensor support member 922 that swings in a seesaw shape with its tip 921a as a fulcrum.
1 is fixedly supported. Also, the sensor mounting mechanism 92
In this case, an urging member 923 such as a leaf spring is provided between the support member 112 and the sensor
21 with respect to the tip 921a) of the toner residual detection sensor 9
1A, and urges the residual toner detection sensor 91 in a direction protruding from the opening 113 as shown in FIG. For this reason, the image forming unit 20 is
1 is improperly attached to or detached from the main body base 11 (in this specification, such a state is referred to as a “non-attached state”).
The entire residual toner detection sensor 91 protrudes from the opening 113 due to the urging force of. Note that the position of the toner residual detection sensor 91 in the non-mounting state is referred to as a “non-mounting position” (FIG. 7A).

On the other hand, the image forming unit 20 is
(In this specification, such a state is referred to as a “mounted state”).
As a result, the toner residual detection sensor 91 moves backward while being opposed to the urging member 923. Note that the position of the toner residual detection sensor 91 in this mounting state is referred to as a “mounting position” (FIG. 2B).

As described above, in this embodiment, the toner residual detection sensor 91 is connected to the main body base 1 of the image forming unit 20.
1 (installation position) corresponding to the mounting state
(b)) and the non-mounting position ((a) in the same figure), and the sensor support member 922 also swings around the fulcrum (the tip 921a of the protrusion 921) in accordance with the movement.

The sensor support member 922 swinging in this manner
On the other end 922b side, as shown in FIG.
The presence / absence detection sensor 94 is fixedly arranged above the position 22b. Then, when the image forming unit 20 is not mounted ((a) in the figure), the other end 922b of the sensor support member 922 is separated from the operating portion 94a of the presence / absence detection sensor 94, and the presence / absence detection sensor 94 is It is in the OFF state, and it is possible to detect that the image forming unit 20 is in the non-mounting state. Conversely, when the image forming unit 20 is in the mounted state (FIG. 13B), the other end 922b of the sensor support member 922 pushes the operating portion 94a of the presence / absence detection sensor 94 upward to detect the presence / absence. The sensor 94 is turned on, and can detect that the image forming unit 20 is in the mounted state.

As described above, in this embodiment, when the image forming unit 20 is properly mounted on the main body base 11 (apparatus main body), the residual toner detection sensor 91 moves to the mounting position, whereas The image unit 20 is the main body base 11
When it is improperly attached to the (apparatus main body) or when it is detached from the main body base 11 (apparatus main body), it is configured to move to the non-mounting position. The presence / absence detection sensor 94 can accurately detect whether the image forming unit 20 is properly mounted on the main body base 11 (apparatus main body).

In this image forming apparatus, the image forming unit 20 is moved by the presence / absence detection sensor 94 to the main body base 11.
Since it is controlled that the residual toner amount in the image forming unit 20 is detected by the toner residual detection sensor 91 on the premise that it is determined that the image forming unit is properly attached to the (apparatus main body), the image forming unit The conventional problem that the amount of residual toner is detected while the device 20 is improperly attached to the main body base 11 (apparatus main body) can be effectively prevented, and the amount of remaining toner can always be accurately detected. Can be.

Further, when this type of sensor is usually mounted on the apparatus main body, additional components such as a mounting member and a spring are required for each sensor. In the above embodiment, the sensor support by the movement of the toner residual detection sensor 91 is required. Since the ON / OFF operation of the presence / absence detection sensor 94 is directly switched by the rotation operation of the member 922, the number of the additional components can be reduced, and the cost of the apparatus can be reduced. By arranging the presence / absence detection sensor 94 directly below the toner remaining detection sensor 91, the presence / absence detection sensor 94 is directly turned on by the movement of the toner remaining detection sensor 91.
N / OFF operation is also possible.

In the above-described embodiment, the image forming apparatus in which the image forming unit 20 having the photosensitive drum and the developing unit is detachably mounted on the apparatus main body (main body base 11) has been described. The configuration of the unit 20 is not limited to this. For example, the present invention is also applied to an image forming apparatus in which a photosensitive drum is previously mounted on the apparatus main body and an image forming unit having a developing unit is detachable. It is possible. That is, according to the present invention, the image forming unit for developing the electrostatic latent image formed on the photosensitive drum with the toner is detachable from the apparatus main body, and furthermore, the toner residual detecting sensor provided on the apparatus main body side is used. While detecting the amount of toner remaining in the image forming unit,
The present invention is applicable to all image forming apparatuses that detect whether or not the image forming unit is mounted on the apparatus main body by a presence / absence detection sensor provided on the apparatus main body side.

[0033]

According to the present invention, when the image forming unit is properly mounted on the apparatus main body, it moves to the mounting position, whereas the image forming unit is improperly mounted on the apparatus main body. When the toner residual detection sensor is configured to move to the non-mounting position when it is removed from the apparatus main body, or when the toner residual detection sensor moves, the image forming unit is moved relative to the apparatus main body by the presence / absence detection sensor. Since it is configured to detect whether or not the image forming unit is properly mounted, it is possible to detect the amount of toner remaining in the image forming unit in a state where the image forming unit is properly mounted to the apparatus main body, The detection can be accurately performed.

In particular, according to the third aspect of the present invention, on the premise that it is determined by the presence / absence detection sensor that the image forming unit is properly mounted on the apparatus main body, the inside of the image forming unit is detected by the residual toner detection sensor. Since the residual toner amount is detected, it is possible to effectively prevent a problem that the residual toner amount is detected while the image forming unit is improperly mounted on the apparatus main body.

[Brief description of the drawings]

FIG. 1 is an external perspective view illustrating an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a side view of the image forming apparatus of FIG.

FIG. 3 is a side view illustrating a frame structure of the image forming apparatus of FIG. 1;

FIG. 4 is a diagram illustrating a state of attachment of the automatic document feeder unit to the upper frame.

FIG. 5 is a partial plan view of the image forming unit with the image forming unit removed from a main body base (apparatus main body).

FIG. 6 is a sectional view taken along line AA of FIG. 5;

[Explanation of symbols]

 Reference Signs List 11 main body base (apparatus main body) 20 image forming unit 91 residual toner detection sensor 92 sensor mounting mechanism 94 presence / absence detection sensor 922 sensor support member 923 urging member

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Keiji Ban, Inventor 1-2-2, Tamazo, Chuo-ku, Osaka-shi Inside Mita Kogyo Co., Ltd. (72) Hidemasa Kizen 1-2-28, Tamazo, Chuo-ku, Osaka-shi Inside Mita Kogyo Co., Ltd. (72) Susumu Taniguchi 1-2-28 Tamazo, Chuo-ku, Osaka-shi Inside Mita Kogyo Co., Ltd. (72) Masayuki Mizuno 1-2-28 Takuma-zo, Chuo-ku, Osaka Mita Industry Co., Ltd.

Claims (3)

[Claims] 1. An image forming unit for developing an electrostatic latent image formed on a photosensitive drum with toner is detachable from an apparatus main body, and the image forming unit is provided with a toner residual detection sensor provided on the apparatus main body side. An image forming apparatus that detects an amount of toner remaining in an image forming unit and detects whether or not the image forming unit is mounted on the apparatus main body by a presence / absence detection sensor provided on the apparatus main body side. The toner remaining detection sensor is configured to move between a mounting position and a non-mounting position in accordance with a mounting state of the image forming unit to the apparatus main body, and the presence / absence detection sensor is configured to detect the toner presence. An image forming apparatus for detecting whether or not the image forming unit is mounted on the apparatus main body according to a position of a residual detection sensor. 2. The image forming apparatus according to claim 1, further comprising: urging means for urging the residual toner detection sensor toward the non-mounting position. 3. Only when the presence / absence detection sensor detects that the image forming unit is attached to the apparatus main body, the result of detection by the toner remaining detection sensor is determined to be valid, and the image formation is performed based on the detection result. 2. The image forming apparatus according to claim 1, wherein an amount of toner remaining in the unit is detected.