JPH01142564A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent the shock generated when a moving part is closed and the distortion of position accuracy of important members by arranging the important members such as an image forming part in a fixing part and shifting the center gravity of the moving part above the opening/closing center of the moving part when the moving part is closed to the fixing part. CONSTITUTION:The important members such as the image forming part 9 are arranged in the fixing part 2a. The title device is constituted so that the center gravity of the moving part 2b comes above its opening/closing center A when the moving part 2b is closed to the fixing part 2a. Under this constitution, an operator separates the moving part 2b from the fixing part 2a to open a sheet conveying route in case of jamming operation. Upon the completion of jamming operation, etc., the moving part 2b to the fixing part 2a and ends work are closed to end the operation. Thus the shock caused by closing is released to prevent the distortion of position accuracy of the important members.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to an image forming apparatus such as a copying machine, a printing machine, or a laser beam printer. Regarding equipment.

(B) Conventional technology Conventionally, image forming apparatuses (
(hereinafter referred to as a laser beam printer) is known, and the laser beam printer 1a is shown in FIG.
As shown in (b), the machine body 2' is configured so that it can be divided into two parts (upper and lower) when handling jams, etc., and the fixed part 2'a of the machine body 2' is used to store sheets. A cassette 3 for transporting sheets, a pair of registration rollers 7 for synchronously transporting sheets, a transfer/separation charger 17, a transport belt 20, and a fixing device 21 are disposed. A forming section 9 is provided.

(c) Problems to be solved by the invention By the way, in the laser beam printer 1a mentioned above,
Since heavy parts such as the image forming section 9 and the laser scanner section 19 are disposed in the moving section 2'b, the strength of the aircraft frame and the strength of the support device that supports the moving section 2'b so as to be openable and closable are limited. It is necessary to ensure sufficient durability, which increases the cost. Furthermore, opening and closing of the moving section 2'b may cause leakage of collected toner from the cleaner of the image forming section 9, as well as the risk of siltation when closing the moving section 2'b. There were problems such as a discrepancy in the positional accuracy between the laser scanner section 19 and the image forming section 9.

Therefore, in order to solve the above-mentioned problems, the present applicant devised a laser beam printer 1b in which an image forming section 9 and a fixing device 21 are arranged in a fixed section 2a of the machine body 2, as shown in FIG. However, in the printer 1b,
If the movable part 2b were to fall by mistake, a crack would occur and there would be a safety problem.

Therefore, the present invention prevents stiffness at the time of closing by starting the closing of the movable part against gravity, and also improves the positional accuracy of the important parts by arranging the important parts such as the image forming part in the fixed part. It is an object of the present invention to provide an image forming apparatus that prevents distortion.

(b) Means for solving the problem The present invention has been made in view of the above-mentioned circumstances. For example, as shown in FIG. Arrange important parts, and move part (2b)
When the movable part (2b) is closed to the fixed part (2a), the center of gravity of the movable part (2b) is located above the opening/closing center (A) of the movable part (2b). be.

(E) Effect Based on the above-mentioned configuration, when processing work such as jam removal, the operator moves the movable part (2b) from the fixed part (2a) to the nrM
Jt, the sheet conveyance path is opened, and after jam removal and the like are performed, the moving part (2b) is closed to the fixed part (2a), and the work is completed.

(F) Examples Examples of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the laser beam printer 1 has a body 2 consisting of a fixed part 2a and a movable part 2b supported by the fixed part 2a by an axis A so as to be openable and closable. A cassette 3 for storing sheets S is disposed above the fixed part 2a, and a paper feed roller 5 for feeding the sheets S from the cassette 3 is disposed in proximity to the cassette 3.
is installed. Further, downstream of the rollers 5, a pair of guides 6 constituting a sheet conveyance path is disposed on the moving portion 2b side, and the pair of guides 6 includes a pair of registration rollers 7 for conveying the sheet S synchronously. Further, an image forming section 9 is disposed downstream of the guide pair 6 on the side of the fixed section 2a, and the image forming section 9 includes a static elimination lamp 11 around the cylindrical photosensitive drum 10, and a secondary charging M12. , a developer M13, a post charger 15, and a cleaner 16. The transfer/separation charging tube 17 is placed close to the photosensitive drum 10 in the moving section 2.
b side, and the drum 10 is located on the fixed part 2a.
It is configured to be exposed by a laser signal from a laser scanner unit 19 provided on the side. Furthermore, downstream of the image forming section 9, a transport belt 20 is connected to a moving section 2b.
A fixing device 2 is provided downstream of the belt 20.
1 is arranged on the fixed part 2a side. A flapper (not shown) is disposed downstream of the fixing device 21,
A pair of paper ejection rollers 23 for ejecting the sheet S to a paper ejection tray 22 protruding from the machine body 2 is disposed downstream of the flapper. Further, on the side branched from the flapper, a pair of paper ejection rollers 26 is arranged to eject the sheet S to the paper ejection tray 25 formed by the outer surface of the moving section 2b.

Since the present embodiment has the above-described configuration, when the laser beam printer 1 obtains image information from an external device, the image information is emitted from a laser emitting unit (not shown).
Then, the image forming section 9 is exposed by the laser scanner section 19, and then the W! The R image forming section 9 forms an image by exposure. At this time, the sheet S is fed from the cassette 3 to the pair of registration rollers 7 by the paper feed roller 5, and is conveyed to the image forming section 9 by the pair of registration rollers 7 in synchronization with the image on the image forming section 9. Furthermore, an image is printed on the sheet S by the image forming section 9, and the sheet S is conveyed to the fixing device 21 by the unfeed belt 20. The sheet S has an image fixed thereon by the fixing device 21, is then guided to a pair of discharge rollers 23 or 26 by a flapper (not shown), and is discharged to a discharge tray 22 or 25 by the pair of rollers 23 or 26.

By the way, if the sheet S jams during conveyance, the operator rotates the moving section 2b of the machine body 2 in the direction of the arrow (see FIG. 1). As a result, the sheet conveyance path is opened (see FIG. 2), and the operator can easily remove the jammed sheet S. Then, when the operator rotates the moving part 2b counterclockwise and returns it to the predetermined position, the jam removal work is completed.

Note that in the above-described embodiment, the sheet conveyance direction is from top to bottom, but it is not limited to this, and as shown in FIG. It may be configured as follows. In the figure, arrow B indicates the front side of the laser beam printer 1', and 30 indicates a paper discharge tray that constitutes the upper surface of the body 2.

Furthermore, as shown in FIG. 4, if the cassette 3 is constructed so that it can be pulled out to the front side of the laser beam printer 1'', and the moving section 2b is also constructed so that it can be rotated toward the front side of the printer 1', It is possible to replenish sheets to the cassette 3 and remove the jam sheet 1-S from the front side of the printer 1', thereby improving operability.

(g) As described in detail, according to the present invention, important components such as the image forming section are disposed in the fixed section, so the weight of the moving section can be reduced.
The frame and support device of the moving part do not require great strength, which can reduce costs. In addition, when the movable part is closed to the fixed part, the center of gravity of the movable part is located above the center of closure of the movable part, which eases the pressure when closing and allows the position of important components to be adjusted. Prevents loss of accuracy.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing an image forming apparatus according to the invention, and FIG. 2 is a front sectional view showing the operation of the invention. 3 and 4 are front sectional views showing other embodiments of the present invention. Further, FIG. 5 is a front sectional view showing an image forming apparatus devised by the applicant. And the sixth
Figures (a) and (bl are front sectional views showing conventional examples. 1, 1', 1', 1 a, 1 b --- image forming apparatus, 2.2' -- body, 2 a, 2' a...fixed part, 2b, 2'b...movable part, A...opening/closing center.

Claims (1)

[Claims] (1) An image forming apparatus including a body configured of a fixed part and a moving part supported by the fixed part so as to be openable and closable, and in which the moving part is separated from the fixed part to open a sheet conveyance path, An important member such as an image forming unit is disposed in the fixed part, and the center of gravity of the moving part is located above the center of opening and closing of the moving part when the moving part is closed to the fixed part. An image forming apparatus characterized by the following.