JPH06175420A - Unit device, unit positioning method and picture image formation device - Google Patents

Abstract

PURPOSE:To provide a unit device of which packaging density is heightened, miniaturization is promoted and safety is improved by providing a safety means against overturning to prevent overturning of the unit at the time when the unit is removed from a frame body of a device main body. CONSTITUTION:A developer unit 10 supports screws 10b, 10c to stir a toner and carry it to a developing container 10a and a magnet sleeve 10d for development free to rotate. Additionally, on a bottom part of the developing container 10a, an engagement part 10f to engage with a rail on the side of a device main body is provided. On a bottom part central part of the developing container 10a, an arm 22 which is a safety means against overturning is installed free to rotate around a support shaft 23 as its center. A rotational angle of the arm 22 is limited by stopper pins 24a, 24b. In case of taking the developer unit 10 out of the device main body and placing it on a floor or on a desk, the arm 22 is rotated to a position shown by a two-point slanting line manually. Consequently, even when weight of the unit 10 is biased, it is possible to prevent overturning.

Description

Detailed Description of the Invention

[0001]

[Industrial applications]

(1) The present invention relates to a unit device in which various units are detachably mounted on a frame of an image forming apparatus such as an electrophotographic copying apparatus.

(2) The present invention relates to a method of positioning various units installed inside an image forming apparatus such as a copying machine or a laser beam printer, and more particularly to a frame provided so as to be movable and removable from the apparatus main body. The present invention relates to a unit positioning method for positioning a plurality of units on a body.

[0003]

[Prior art]

(1) Conventionally, there is an electrophotographic copying apparatus as an apparatus in which a unit having various functions is detachably attached to a frame of an image forming apparatus. For example, a full-color electrophotographic copying machine is equipped with a reader unit and a printer unit. The printer unit is provided with a process unit having various functions such as a transfer drum, a developing unit, and a fixing unit around the photosensitive drum. These process units are used for maintenance inspection and jam (paper jam) processing. It is configured to be removable from.

Description will be made with reference to, for example, the developing device unit shown in FIG. FIG. 12 is a cross-sectional view of a developing unit containing C (cyan) and Y (yellow) color toners. Screws 103 and 104 that convey and agitate toner as a developer and a carrier are rotatably supported with respect to the developing container 105 in the developing unit units 101 and 102, and further, inside to convey the toner to the photosensitive drum 106. A sleeve 107 having a built-in magnet roller is rotatably supported. In addition, a blade 108 for regulating the amount of toner coating on the sleeve 107 is fixed near the sleeve 107.

On the side of the main body of the apparatus, as shown in FIG.
A developing device rail 110 is supported on a stay 109 fixed to a frame (not shown) via a step screw 111 so as to be movable in the arrow direction of the drawing. A return spring 112 is connected between the stay 109 and the developing device rail 110 to urge the developing device rail 110 in one direction.
A pressure spring (leaf spring) 1 is attached to the developing device rail 110.
13 is fixed. A pressure cam 114 is provided at a position corresponding to the pressure spring 113, and the cam shaft 1
It is rotatably supported by 14a.

By rotating the pressure cam 114 by 180 °, the pressure spring 113 and the developing device rail 110 move in the direction of approaching the photosensitive drum 106, and the developing device units 101 and 102 are moved to predetermined positions and applied. Perform pressure positioning. As shown in FIG. 12, each color developing device unit includes a rail engaging portion 1 provided at the bottom of the developing container 105.
05a is fitted in the groove portion of the developing device rail 110, and is slid from the front side of the drawing to the back side of the drawing to be inserted into the apparatus main body. The thrust direction of each developing unit is fixed by fixing the developing container 105 and the rail 110 from the front side of the drawing with a screw or the like. in this way,
Each developing device unit is attached to and detached from the apparatus main body by engaging the rail engaging portion 105a with the developing device rail 110.

The basic structure of attachment / detachment is the same in units other than the developing unit. FIG. 14 shows a detachable structure of another unit. The predetermined unit (for example, fixing unit) 115 has a positioning pin 11 on the back side (left side in the drawing).
6. Unit side plates 117 are provided on the front side (right side in the drawing), and the unit side plate 117 has front positioning pins 118. A rail engaging portion 115a is formed on the bottom of the predetermined unit 115.

Further, front and rear side plates 119, 120 on the apparatus body side
A rail 121 is formed between the side plates 11 and 11.
Positioning holes 119a and 120a are formed in the holes 9 and 120, respectively. When the predetermined unit 115 is mounted on the main body of the apparatus, the rail engaging portion 115a is engaged with the rail 121 and slid from the right side to the left side in the drawing.
At this time, the positioning pins 118 and 116 have the positioning holes 1
19a and 120a are fitted to each other to position the unit, and the unit side plate 117 is attached to the front side plate 1 on the apparatus main body side.
The fixing of the predetermined unit 115 is completed by fixing it to the screw 19 with the screw 122.

(2) Conventionally, various units equipped in an image forming apparatus such as a copying machine or a laser beam printer are pulled out to the front side in the direction orthogonal to the sheet conveying direction to perform jam (paper jam) processing and maintenance. An example of Figure 16
It will be described with reference to FIGS. In FIG. 16, 201 is a fixing unit for fixing the image on the sheet by heat, pressure or the like. Reference numerals 202 and 203 denote front and rear side plates of the apparatus main body, and a stay 204 connecting the front side plate 202 and the rear side plate 203 also serves as a rail when the fixing unit 201 is attached and detached. As shown in FIG. 17, two pins 207 and 208 are provided on the front plate 205 and the rear plate 206 of the fixing unit 201, respectively. Side plate 202,
The fixing unit 201 is configured to be positioned by fitting it into a positioning hole (not shown) provided in the rear plate 203.

When the fixing unit 201 is pulled out to the right side of the arrow in FIG. 16, the bottom plate 209 of the fixing unit 201 and the stay 204 are in contact with each other, and the fixing unit 201 is moved to the left side of the arrow. When set by the above, the pins are positioned on the apparatus main body side by the pins 207 and 208 described above, so that a gap of α is formed between the bottom plate 209 and the stay 204 as shown in the figure.

FIG. 18 shows still another example, in which a plurality of units 211 and 212 are fixed to a frame 210, and the units 211 and 212 together with the frame 210 are on the front side of the apparatus (lower side in the drawing). Is configured to be pulled out to. The frame 210 includes the front and rear side plates 20 on the apparatus body side.
Positioning is performed by inserting pins 207 and 208 into 2,203. The plurality of units 211, 21
Driving force is transmitted from driving sources 213 and 214, respectively, to rotate rollers and the like in each unit.

[0012]

[Problems to be Solved by the Invention]

(1) However, in the above conventional technique (1),
Since each process unit equipped in the copying machine does not have a fall-prevention means, if the weight balance of each unit is imbalanced, the unit will fall over when it is removed, and the unit may be damaged, scratched, or soiled. There was a risk of it. For example, in the developing device unit, the weight is concentrated near the sleeve 107, the center of gravity is biased as shown in FIG. 15, and it falls in the arrow direction. As a result, the sleeve 107 may collide with a surface such as the floor and may be damaged.

In order to solve the above problems, a dedicated stand is provided for each unit, and each unit is placed on the dedicated stand. However, it is necessary to make a dedicated stand for each type of unit. Since it is cumbersome and the manufacturing cost is high, and the dedicated stand is not required when mounting the unit,
Problems such as the need for a space for accommodating a dedicated stand occur. It is also possible to widen the bottom to increase the stability of each unit, but the unit becomes large and there is no space in a device with a high packing density of each unit, so wide the bottom. Was difficult.

(2) However, the above prior art (2)
In the above, there were the following problems. First, as shown in FIGS. 16 and 17, in the method of projecting positioning pins at the front and rear of the unit and positioning them on the side plate on the apparatus main body side, if the number of units is one, there is not much problem. Assuming that there are a plurality of units on the frame and each unit has the above-mentioned configuration, when the number of units on the frame is n, the number of positioning pins is 4n and the number of parts increases. Manufacturing cost is high. Since it is necessary to pull out and mount the frame while fitting a large number of positioning pins, the operation feeling becomes very heavy. In order to reduce the weight of the operation feeling, if the length of the positioning pin is changed or the shape is changed by forming the taper portion at the tip end in the unit mounting direction, the same positioning pin is different in type. A large number of items are required, which is not convenient in terms of management or assembly. In the final set state, the unit is suspended by pins on the back side and the front side of the device body, and when the unit is pulled out from the device body, it is placed on the frame by its own weight. Only regulated, not fixed. Therefore, for example, when a liquid release agent (oil) for preventing the sheet from being wound around the fixing roller is mounted as in the fixing unit, the fixing unit is completely fixed. Unexpected external force may cause vibration or shock, resulting in oil leakage. If the amount of change in the above unit from the state without being fixed to the state in which it is suspended by the positioning pin is large, the liquid surface of the liquid oil will be violent and the oil will be spilled, and it is difficult to accurately grasp the liquid surface.

Further, when a plurality of units are completely fixed on the frame body and only the frame body is positioned on the front and rear side plates of the apparatus main body as shown in FIG. 18, the following problems occur. That is, if the driving sources for driving a plurality of units are the same, the driving force may be transmitted to each unit after being fixed to the frame, but if the driving sources are different depending on the feeling of each unit or the driving source is different, If the same unit is desired to be treated as an independent unit in terms of service maintenance and assemblability, a plurality of drive transmission places are required for the frame. Although the frame body and the rear side plate of the main body of the apparatus are accurately centered, the drive input portion of each unit on the frame body has a tolerance for stacking parts with respect to the rear side plate. Therefore, misalignment of the drive transmission portion becomes a problem, and shake may be transmitted depending on the unit.

The object of the present invention is to solve the above problems of the prior art (1).
It is to provide a unit device which solves the problem, improves the safety of the unit, promotes miniaturization, and increases the mounting density.

The object of the present invention is to solve the above problems of the prior art (2).
It is an object of the present invention to provide a unit positioning method that solves the above problem and realizes cost reduction, operability improvement, and safety improvement.

[0018]

A typical means for solving the above-mentioned problem (1) of the prior art and applied to the embodiments described below is a unit device which is attachable to and detachable from the frame of the device body. A fall prevention unit is provided for preventing the unit from falling when the unit is removed from the frame.

A typical means for solving the above-mentioned problem (2) of the prior art and applied to the embodiment described below is to position a plurality of units on a frame body which is movable and detachable with respect to the apparatus main body. In the unit positioning method for
The unit driving side is positioned by a plurality of sets of positioning means, and the non-drive transmission side is positioned by only one set of positioning means.

[0020]

According to the above means (1), when the unit is detached from the frame of the main body of the apparatus, even if the weight balance of the unit is imbalanced, the fall prevention means prevents damage, scratches, dirt, etc. due to the fall of the unit. Can be prevented.

According to the above means (2), the unit driving side is positioned by a plurality of sets of positioning means, and the non-drive transmission side is positioned by only one set of positioning means.

[0022]

[First Embodiment] An embodiment of the present invention to which the means (1) is applied will be described below with reference to the drawings. In this embodiment, a full-color electrophotographic copying apparatus is used as an image forming apparatus, and a developing unit is used as an example of a unit provided with a fall prevention unit. FIG. 1 is an explanatory diagram showing a fall prevention mechanism of a developing device unit, and FIG. 2 is a sectional explanatory diagram showing the overall structure of a copying apparatus.

First, the schematic structure of the copying apparatus will be described with reference to FIG. The copying apparatus includes a reader unit A that is a reading system and a printer unit B that is a recording system. First, the structure of the reader unit A will be described. The original on the platen 1 is scanned by the lamp 2 and the optical mirrors 3a, 3b, 3c to irradiate the original surface from the lamp 2, and the reflected light is passed through the lens 4 through the lens 4. An image is formed on a photoelectric conversion element 5 such as a CCD to convert image information from optical information into an electric signal.

Next, the structure of the printer unit B will be described. The printer unit B is equipped with a plurality of process means for forming an image by acting on the photosensitive drum 6 which is an image carrier and a recording sheet which is a recording material. Reference numeral 7 is a laser scanner unit having a laser oscillator, a polygon mirror, and the like, which irradiates a laser beam modulated according to the image information read by the reader unit A. The lenser light emitted by the laser scanner unit 7 is imaged on the photosensitive drum 6 that is uniformly charged in advance via the lens 8 and the reflection mirror 9 to form an electrostatic latent image (exposure). ). A developing device unit 10 is provided around the photosensitive drum 6, and developing devices 10Y, 10C, 10M, and 10K containing toners of respective colors, which are developers, are positioned at predetermined timings, and latent images corresponding to respective colors are provided. Each color toner is supplied to the image to develop the image.

On the other hand, the recording sheets are cassettes 11a and 11b.
Is fed by the pickup rollers 12a and 12b,
The sheets are separated one by one by the separation rollers 13a and 13b, and are conveyed by the intermediate conveying roller pair 14. Then, the skew is corrected by the registration roller 15 which is temporarily stopped, and after the toner image is subjected to a predetermined timing, it is conveyed to the transfer drum 16 which is a sheet carrier and electrostatically charged. The toner image is attracted and conveyed, and the toner image is transferred to the recording sheet at the transfer portion.

The recording sheet after the image transfer is separated from the transfer drum 16 by the separating claw 17, is conveyed to the fixing unit 19 by the conveying unit 18, the toner image is fixed on the recording sheet, and then the discharging roller 20. And is discharged to a discharge tray 21 provided outside the apparatus.

Next, the fall prevention mechanism of the developing device unit 10 will be described with reference to FIG. FIG. 1 shows a developing unit 10
FIG. The developing device unit 10 includes a developing container 10
Screws 10b and 10c for agitating and conveying the toner in a
In addition, the developing magnet sleeve 10d is rotatably supported, and a blade 10e for regulating the toner coat amount on the developing magnet sleeve 10d is provided. Further, at the bottom of the developing container 10a, there are provided two engaging portions 10f which engage with the rail on the apparatus main body side.

An arm 22 as a fall prevention means is attached to the center of the bottom of the developing container 10a so as to be rotatable around a support shaft 23, and the rotation angle of the arm 22 is regulated by stopper pins 24a and 24b. Has been done. Above arm 22
Is as shown by the two-dot chain line in the side view and bottom view of FIG.
First to prevent falling when the developer unit 10 is removed
The unit 10 is rotatably mounted between a position and a second position which does not interfere with the mounting of the unit 10 on the apparatus body as shown by solid lines in the front view and the bottom view. In particular, in the second position, the arm 22 is held at a position where it does not project in the longitudinal direction from the engagement portion 10f in the front view so that the rail on the apparatus main body side and the arm 22 do not interfere with each other during mounting.

When the developing device unit 10 is taken out from the apparatus main body and placed on the floor or desk, the weight of the unit 10 is reduced by manually rotating the arm 22 to the position shown by the chain double-dashed line in FIG. Even if it is biased, it can be prevented from falling. Further, when the developing device unit 10 is mounted on the main body of the apparatus, if the arm 22 is manually rotated to the position shown by the solid line in FIG. 1, the unit 10 can be mounted smoothly without interfering with the rail on the main body side. You can

According to the above construction, it is possible to prevent the unit from tipping over when it is detached from the main body of the apparatus, and it is possible to eliminate damage, scratches and dirt on the unit, thereby improving safety. Further, a dedicated stand or the like for mounting the unit is not necessary, and further miniaturization of the unit itself can be promoted and the mounting density of the device can be increased.

[Second Embodiment] Next, another example of the overturning prevention mechanism of the developing device unit 10 in the first embodiment will be described with reference to FIG.
And FIG. 4 will be described. Since the schematic structure of the copying apparatus is the same as that of the first embodiment, the same members are designated by the same reference numerals and the description thereof is omitted. In the first embodiment, the arm 22 which is the fall prevention means is manually rotated to the first position and the second position. It is configured to rotate to the first position and the second position.

In FIG. 3, a torsion coil spring 25 is attached to a support shaft 23, which is the center of rotation of the arm 22,
The arm 22 is constantly urged to rotate in the arrow direction, that is, to the first position. As a result, when the developing device unit 10 is removed, the arm 22 always tries to rotate to the first position, and when the unit 10 is taken out from the apparatus main body, the arm 22 is already set to the first position. It is possible to prevent falls.

Next, the operation of the arm 22 when the developing device unit 10 is mounted on the apparatus main body will be described with reference to FIG. FIG. 4 is a top view showing the relationship between the arm of the developing device unit 10 and the rail on the apparatus main body side. In FIG. 4A, a rail 28 provided between the front and rear side plates 26, 27 of the apparatus body
The engaging portion 10f on the back side of the developing device unit 10 is engaged with the groove. At this time, the arm 22 is biased to the first position by the torsion coil spring 25. In FIG. 4B, when the developing device unit 10 is further pushed along the rail 28, the outer circumference 22a of the arm 22 contacts the inner circumference 28a of the rail and resists the biasing force of the torsion coil spring 25. Starts to rotate.
In FIG. 4 (c), when the developing device unit 10 is further pushed in, the second arm 22 remains in contact with the inner wall of the rail 28.
It is rotated and held in the position, and the mounting operation of the unit is completed. The arm 22 when the developing device unit 10 is taken out
The order of the operation of is reversed from the above description.

According to the above construction, the arm can be rotated to the first and second positions according to the attaching / detaching operation of the unit, the operability can be improved, and the arm 22 can be mounted on the rail 28 in the mounted state. Since the spring is pressed by the elastic force of the spring 25, the shock of the unit can be absorbed and the accuracy of the device is improved.

[Third Embodiment] Next, another example of the overturning preventing mechanism of the developing device unit 10 in the first embodiment will be described with reference to FIG.
Will be described with reference to. Since the schematic structure of the copying apparatus is the same as that of the first embodiment, the same members are designated by the same reference numerals and the description thereof is omitted. In this embodiment, the overturning preventing means of the unit also serves as the retaining means in the attaching / detaching direction of the unit. FIG. 5 is a top view showing the relationship between the arm of the developing device unit 10 and the rail on the apparatus main body side.

In FIG. 5, an arm 29 is rotatably attached to the bottom of the developing unit 10 as in the first embodiment, and a torsion coil spring is used as in the second embodiment.
It is biased to the first position by 25. A lock portion 29a, which is partially cut, is formed at the tip of the arm 29, and an opening 28b is formed at a predetermined position on the side wall of the rail 28 on the apparatus main body side.

Next, the operation of the arm 29 when the developing device unit 10 is attached to the apparatus main body will be described. Figure 5
In (a), the engaging portion 10f on the back side of the developing device unit 10 is engaged with the groove of the rail 28 provided between the side plates 26, 27 of the apparatus main body. At this time, the arm 29 is biased to the first position by the torsion coil spring 25. In FIG. 5 (b),
When the developing device unit 10 is further pushed along the rail 28, the outer circumference 29b of the arm 29 contacts the inner circumference 28a of the rail, and the arm 29 starts to rotate against the biasing force of the torsion coil spring 25. In FIG. 5C, the developing device unit 10 is further added.
When the unit 10 is pushed in and the unit 10 strikes the side plate 27, the lock portion 29a of the arm 29 engages with the opening portion 28b of the rail 28 to prevent the unit 10 from coming off in the attaching / detaching direction. When the developing device unit 10 is removed, as shown in FIG. 5C, the button 30a, the spring 30b, the link 30c, the arm
The lock releasing mechanism 30 including 30d is provided on the apparatus main body side, and the button 30a is pushed down to release the engagement between the lock portion 29a and the opening portion 28b, so that the unit 10 can be removed.

According to the above construction, by changing the shapes of the arm as the fall prevention means and the rail on the apparatus main body side, it is possible to serve also as the unit retaining means, which simplifies the apparatus and reduces the cost. It can be promoted, and the work of fixing the unit with screws or the like becomes unnecessary.

[Fourth Embodiment] Next, another example of the fall prevention mechanism of the developing device unit 10 in the third embodiment will be described with reference to FIG.
And FIG. 7 will be described. Since the schematic structure of the copying apparatus is the same as that of the first embodiment, the same members are designated by the same reference numerals and the description thereof is omitted. The present embodiment shows another example of the unit device in which the overturning preventing means of the unit shown in the third embodiment also serves as the retaining means in the attaching / detaching direction of the unit, and is integrated with a stopper for retaining the unit. The formed release lever is used as a fall prevention means.

In FIG. 6, the developing device unit 10 is slidably suspended by engaging an engaging portion 10f with a rail 28 provided between the front and rear side plates 26, 27 of the apparatus main body. Positioning of the developer unit 10 in the vertical and horizontal directions is performed by positioning pins 10g protruding from the unit 10,
10h is a positioning hole provided on the side plates 26, 27 on the device body side.
It is performed by inserting into 26a and 27a, respectively.

A lever 32 is rotatably attached to the developing device unit 10 about a pin 31.
The rotation angle is regulated by 33 and 34 so as to rotate between the solid line position in the figure and the position indicated by the chain double-dashed line. A groove 32a for a stopper is formed in the lever 32, and the lever 32 has a groove 32a engaged with an edge portion of the front side plate 26 at a solid line position in FIG.

When the developing device unit 10 is to be removed from the main body of the apparatus, the grip 32b of the lever 32 is rotated in the direction of arrow A to the position shown by the chain double-dashed line in the figure, so that the groove The engagement state between the front plate 26 and 32a is released, and the unit 10 can be moved in the front-rear direction (left-right direction in the drawing).

FIG. 7 shows a state in which the lever 32 in FIG. 6 is rotated to the position shown by the chain double-dashed line. In FIG. 7, the tip 32c of the grip 32b of the lever 32 is formed flush with the bottom of the unit, and the pin 33 restricts further rotation. Therefore, when the developing device unit 10 is detached from the main body of the apparatus and placed on the floor or the like, even if the weight of the developing device unit 10 is uneven, it is possible to prevent the lever 32 from supporting and falling.

In the first to fourth embodiments, the developing device unit is used as the unit device.
The unit is not limited to this, and may be another unit (for example, a fixing unit, a transfer drum unit, etc.). Further, the image forming apparatus is not limited to the copying apparatus and may be another apparatus (for example, a laser beam printer).

[Fifth Embodiment] Next, an embodiment of the present invention to which the means (2) is applied will be described with reference to the drawings. This embodiment will be described using a full-color electrophotographic copying machine as an image forming apparatus. 8 is a sectional view of the fixing unit, FIG. 9 is a sectional view of the transport unit, and FIG.
FIG. 11 is a top view of the entire frame body, and FIG. 11 is a cross-sectional explanatory view showing the overall structure of the copying apparatus.

First, the schematic construction of the copying apparatus will be described with reference to FIG. The copying apparatus includes a reader unit A that is a reading system and a printer unit B that is a recording system. First, the structure of the reader unit A will be described. The original on the platen 41 is scanned by the lamp 42 and the optical mirrors 43a, 43b, 43c to illuminate the original surface from the lamp 42, and the reflected light is passed through the lens 44. CCD
An image is formed on the photoelectric conversion element 45 such as, and the image information is converted from the optical information into an electric signal.

Next, the structure of the printer unit B will be described. The printer unit B is equipped with a plurality of process means for acting on the photosensitive drum 46 as an image carrier and a recording sheet as a recording material to form an image. Reference numeral 47 is a laser scanner unit having a laser oscillator, a polygon mirror, and the like, which emits laser light modulated according to the image information read by the reader unit A. The laser light emitted by the laser scanner unit 47 is imaged through the lens 48 and the reflection mirror 49 on the photosensitive drum 46 that is uniformly charged in advance to form an electrostatic latent image (exposure). .

A developing device unit 50 is provided around the photosensitive drum 46, and developing devices 50Y, 50C, 50M and 50K containing toners of respective colors, which are developers, are positioned at predetermined timings, and the developing devices 50Y, 50C, 50M and 50K are positioned for each color. Toners of respective colors are respectively supplied to the corresponding latent images for development.

On the other hand, the recording sheets are fed from the cassette 51 by the pickup roller 52, separated one by one by the separating roller 53, and conveyed by the intermediate conveying roller pair 54. Then, the skew is corrected by the registration roller 55 which is temporarily stopped, and the toner image is conveyed to the transfer drum unit 56 at a predetermined timing and then electrostatically transferred onto the transfer drum 56a. The toner image is attracted and conveyed, and the toner image is transferred to the recording sheet at the transfer portion.

The recording sheet after the image transfer is separated from the transfer drum 56a by the separating claw 57 and is conveyed to the fixing device unit 59 by the conveying unit 58 to fix the toner image on the recording sheet, and then the discharging roller 60. And is discharged to a discharge tray 61 provided outside the apparatus.

In the above copying apparatus, the stay 63 of the frame is fixed to the accuride rail 62 supported by the front and rear side plates of the main body of the apparatus, and the transfer drum unit 56, the transport unit 58, and the fixing device are fixed on the stay 63. Unit 59 is installed. Jam (paper jam) while the recording sheet is being conveyed from the transfer drum unit 56 to the fixing unit 59
Or the transfer drum unit 56, the transport unit
58, the above-mentioned three units can be pulled out in a direction orthogonal to the sheet conveying direction (front side in the direction perpendicular to the paper surface of FIG. 11) when the parts inside the fixing device unit 59 are replaced or maintained. .

Next, a method of positioning each unit with respect to the frame will be described with reference to FIGS. 8 to 10. First, FIG. 8 shows a method for positioning the fixing unit 59 with respect to the frame body. Reference numerals 64 and 65 are front and rear plates of the apparatus main body, and the unit is positioned between the front and rear side plates 64 and 65. is there. The frame formed on the main body of the device is
6, the rear side plate 67, and the stay 63 passed between the front and rear side plates 66, 67. The stay 63 serves as a mounting surface when the fixing unit 59 is mounted.

The fixing unit 59 has a fixing unit 59a, a front side plate 59b, a rear side plate 59c and a bottom plate 59d.
d is passed between the front and rear side plates 59b and 59c, and penetrates the front side plate 59b and is fixed to the front side plate 66 of the frame. That is, the front side of the fixing device unit 59 is positioned and fixed to the frame body. Reference numeral 68 denotes a positioning pin provided on the front side plate 66 of the frame body, which is inserted into a positioning hole provided on the front side plate 64 of the apparatus main body for positioning. Reference numeral 69 denotes a positioning pin provided on the rear side plate 59c of the fixing unit 59, which is provided above the rear side plate 67 of the frame body, and is inserted into a positioning hole provided on the rear side plate 65 of the apparatus main body. Be positioned. As shown in FIG. 10, a drive transmission portion 59e for transmitting the drive force from the apparatus main body side is formed on the rear side plate 59c side of the fixing device unit 59 by a coupling.

Further, the front side plate 59b of the fixing unit 59,
The amount of protrusion of the rear side plate 59c from the bottom plate 59d is slightly different (the front side plate 59b is in contact with the stay 63 of the frame body, but the rear side plate 59c has a gap α with the stay 63). Has been formed). Therefore, the frame body is pulled out from the front side plate 66 side, and the positioning pins 68 and 69 are attached to the front and rear side plates 64 and 65 on the apparatus main body side.
When it is removed from the fixing unit, the gap α between the rear plate 59c of the fixing unit 59 and the stay 63 of the frame becomes 0, and the fixing unit becomes
59 is pulled out slightly tilted to the left.

When the fixing unit unit 59 is mounted on the main body of the apparatus, the positioning hole formed on the rear side plate 65 on the side of the apparatus main body is located above the positioning pin 69 provided on the rear side plate 59c on the unit side by α. Therefore, the fixing unit 59 can be installed in parallel by slightly lifting the back side (left side in the drawing). By assuring this gap α, the positional relationship between the positioning pin 69 and the positioning hole does not reverse, and an unreasonable force is not applied when the unit is mounted.

Further, when the fixing unit unit 59 is pulled out from the main body of the apparatus, the stay 63 of the frame is supported by the acryl rail 62, but the entire frame is cantilevered on the front side plate 66 side. The weight of the frame and the fixing unit 59 mounted on the frame causes the front side (right side in the drawing) to be lowered as a whole. At this time, since the fixing device unit 59 descends to the left as described above, the fixing device unit 59 can be kept substantially horizontal when being attached and detached by designing to cancel the inclination.

In the fixing device 59a of the fixing device unit 59, there may be a case where a liquid release agent for preventing the recording sheet from being wound around the roller is stored, and the above-mentioned gap α is provided. Thus, by keeping the fixing device unit 59 always horizontal, it is possible to prevent the liquid such as the release agent from spilling.

Next, a method of positioning the carrying unit 58 with respect to the frame will be described. In FIG. 10, the transport unit 58 includes transport rollers 58a and 58b, a shaft 58c, and the above-mentioned transport rollers.
It has a conveyor belt 58d stretched over 58a, 58b,
Transfer drum unit arranged on the upstream side in the sheet conveying direction
The recording sheet is conveyed to the fixing device unit 59 from 56. Roller shafts 58a ₁ and 58 of the transport rollers 58a and 58b
The b ₁ and the shaft 58c are rotatably supported by the front and rear side plates 70 and 71, and the front side plate 70 is fixed to the front side plate 66 of the frame body.
Above the end on the side plate 71 side after the roller shaft 58b ₁ is provided with a drive transmitting portion 58e provided with a coupling, for transmitting a driving force from the apparatus main body.

As shown in FIGS. 9 and 10, the positioning of the carrying unit 58 is performed by a positioning pin 72 formed on an extension of the roller shaft 58a ₁ of the carrying roller 58a on the drive transmission side (upper side of FIG. 10). Then, positioning is performed by inserting the positioning pin 73 provided on the rear side plate 71 into the positioning hole formed in the rear side plate 65 of the apparatus main body. The non-drive transmission side (Fig.
In FIG. 10 (the lower side of the drawing), the positioning pins 68 provided on the front side plate 66 of the frame body are inserted into the positioning holes provided on the front side plate 64 of the apparatus main body for positioning.

When the carrying unit 58 is pulled out to the front side (right side in FIG. 9), the positioning pins 72 and 73 are disengaged from the rear side plate 65 of the main body of the apparatus, but a long length provided at the upper edge of the rear side plate 67 of the frame body. Transport unit because it is supported by holes or U-shaped holes
58 can be pulled out in a stable state.

According to the above construction, the fixing device unit 59 and the transport unit 58 are positioned on the drive transmitting side by two sets of positioning pins, and the non-drive transmitting side is positioned by one positioning pin provided on the frame. It is being appreciated. The non-driving transmission sides of the fixing unit 59 and the transport unit 58 are completely fixed to the frame.

Therefore, the number of parts can be greatly reduced, the manufacturing cost can be reduced, the kinds of parts used can be suppressed to the minimum source, the parts can be easily managed, and the assembling property can be improved. In addition, the feeling of operation when attaching and detaching the frame is lightened, and the operability during jam handling and maintenance can be improved.
Furthermore, since the unit can be supported in a stable state, it is difficult for vibration and impact to be transmitted inside the unit, and safety can be improved.

In the fifth embodiment, positioning pins are provided at two positions on the drive transmission side of the fixing unit unit 59 and the transport unit 58 for positioning, but instead of the above units, positioning is performed on the frame side. Pins may be provided for positioning. Especially effective when each unit mounted on the frame is fixed to the rear plate of the frame with a certain degree of accuracy, and if there is no hindrance to drive transmission to each unit within that accuracy Is.

The unit mounted on the frame is not limited to the above unit, but may be another unit (for example, a developing unit). Further, the image forming apparatus is not limited to the copying apparatus and may be another apparatus (for example, a laser beam printer).

[0065]

【The invention's effect】

(1) As described above, according to the present invention, when the unit is removed from the frame of the apparatus main body, even if the weight balance of the unit is imbalanced, the fall prevention unit prevents damage, scratches, stains, etc. due to the fall of the unit. It is possible to improve safety. Further, a dedicated stand or the like for mounting the unit is not required, so that miniaturization of the unit can be promoted and the mounting density of the device can be increased.

(2) As described above, according to the present invention, the unit driving side is positioned by a plurality of sets of positioning means, and the non-drive transmission side is positioned by only one set of positioning means to reduce the number of parts. The manufacturing cost can be reduced by greatly reducing the cost. In addition, the number of types of parts used is kept to a minimum, part management is easy, and ease of assembly is also improved. In addition, the feeling of operation when attaching and detaching the frame becomes lighter,
It is possible to improve operability during jam handling and maintenance. Furthermore, since the unit can be supported in a stable state, vibrations and shocks are less likely to be transmitted inside the unit, and safety can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a fall prevention mechanism of a developing device unit.

FIG. 2 is a cross-sectional explanatory diagram showing an overall configuration of a copying apparatus.

FIG. 3 is an explanatory view showing another example of the overturn prevention mechanism of the developing device unit.

FIG. 4 is an explanatory diagram showing another example of a fall prevention mechanism of the developing device unit.

FIG. 5 is an explanatory diagram showing another example of the overturn prevention mechanism of the developing device unit.

FIG. 6 is an explanatory view showing another example of the overturn prevention mechanism of the developing device unit.

FIG. 7 is an explanatory diagram showing another example of the overturn prevention mechanism of the developing device unit.

FIG. 8 is a cross-sectional view showing a positioning structure of a fixing device unit.

FIG. 9 is a cross-sectional view showing a positioning structure of a transport unit.

FIG. 10 is a top view of the entire frame body on which the unit is mounted.

FIG. 11 is an explanatory cross-sectional view showing the overall configuration of the copying apparatus.

FIG. 12 is a sectional view showing a configuration of a conventional developing device unit.

FIG. 13 is an explanatory diagram showing a configuration of a mounting portion of a conventional developing device unit.

FIG. 14 is an explanatory diagram showing a positioning configuration of a conventional developing device unit.

FIG. 15 is an explanatory diagram showing a gravity center position of a conventional developing device unit.

FIG. 16 is a side view showing a positioning structure of a conventional fixing device unit.

FIG. 17 is a perspective view showing a positioning structure of a conventional fixing unit.

FIG. 18 is a top view showing a conventional positioning structure for a frame.

[Explanation of symbols]

 A ... Reader unit B ... Printer unit 1 ... Platen 2 ... Lamps 3a, 3b, 3c ... Optical mirrors 4, 8, 48 ... Lens 5 ... Photoelectric conversion element 6,46 ... Photosensitive drum 7, 47 ... Laser scanner unit 9, 49 ... Reflecting mirror 10,50 ... Developer unit 10a ... Developing container 10b, 10c ... Screw 10d ... Development magnet sleeve 10e ... Blade 10f ... Engaging part 10g, 10h, 68,69,72,73 ... Positioning pin 11a, 11b , 51 ... Cassettes 12a, 12b, 52 ... Pickup rollers 13a, 13b, 53 ... Separation rollers 14, 54 ... Intermediate conveying roller pair 15, 55 ... Registration rollers 16, 56a ... Transfer drum 17, 57 ... Separation claws 18, 58 ... Transport unit 19, 59 ... Fixing unit 20, 60 ... Ejection rollers 21, 61 ... Ejection trays 22, 29, 30d ... Arms 23 ... Spindles 24a, 24b ... Stopper pins 25 ... Torsion coil springs 26, 59b, 64, 66, 70 Front plate 27, 59c, 65, 67, 71 ... Rear plate 28 ... Rail 28a ... Opening 29a ... Lock part 30 ... Lock release mechanism 30a ... Button 30b ... Spring 30c ... Link 31, 33, 34 ... Pin 32 ... Lever 32a ... Groove 32b ... Grip part 56 ... Transfer drum unit 59a ... Fixing device 59d ... Bottom plate 58e, 59e ... Drive transmission part 62 ... Acculide rail 63 ... Stay

Claims (9)

[Claims] 1. A unit device attachable to and detachable from a frame body of a device body, comprising a fall prevention means for preventing a unit from falling when detached from the frame body. 2. The fall prevention means is movable to at least a first position for preventing a fall when the unit is removed and a second position for not disturbing the operation of the apparatus body when the unit is attached. The unit device according to claim 1. 3. The unit device according to claim 2, wherein the tipping prevention unit moves to the first position and the second position in accordance with an attaching / detaching operation of the unit device to / from the device body. 4. The unit device according to claim 1, wherein the fall prevention unit also serves as a retaining unit when the unit is attached. 5. An image forming apparatus comprising: an image bearing member; and a process unit having various unit devices according to claim 1, which act on the image bearing member or a recording material to form an image. 6. A unit positioning method for positioning a plurality of units on a frame body that is movable and attachable / detachable with respect to the apparatus body with respect to the apparatus body. A unit positioning method characterized in that positioning is performed by positioning means, and positioning on the non-drive transmission side is performed by only one set of positioning means. 7. The non-drive transmission side of the plurality of units is
The unit positioning method according to claim 6, wherein the unit is fixedly positioned with respect to the frame. 8. When the units having different drive sources exist in the plurality of units, the number of sets of positioning means on the unit drive side with respect to the apparatus main body is equal to or more than the number of different drive sources. The unit positioning method according to claim 6. 9. An image carrier, and a process unit that acts on the image carrier or a recording material to form an image by using various units positioned by the unit positioning method according to claim 6. An image forming apparatus having: