JPH0611953A - Structure for installing screen lamp in image forming device - Google Patents

Abstract

PURPOSE:To enable easy installation of a screen lamp by turning a belt-shaped photoreceptor along rollers, and installing the screen lamp while using the rollers as references. CONSTITUTION:A front vertical plate 10 and a rear vertical plate 11 are connected in parallel to each other by a plurality of connecting horizontal bars 12 to form a photoreceptor supporting frame 13 and a belt-shaped photoreceptor 15 is wound to the frame 13 via a plurality of rollers 14. In this case, the photoreceptor 15 turns in contact with the upper surface of of each of the pair of rollers 14, 14 and a screen lamp 28 is pressed against the lower surface of a rotating bush supporting the pair of rollers 14, 14. Therefore, not only the space (cavity) between the screen lamp 28 and the upper surface of the photoreceptor 15 is always kept at a predetermined value, but also the work of installing the screen lamp 28 is facilitated since the screen lamp 28 can be installed simply when pressed against the lower surface of the rotating bush.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting a screen lamp for forming a screen-shaped non-charged portion on a photosensitive member in an image forming apparatus used for an electrophotographic copying machine, a printer, a facsimile or the like.

[Prior art]

As an image forming apparatus, an image forming apparatus such as a primary charging device, an image exposing section, a developing device, a transfer charging device, and a cleaner is arranged around the image carrier, and the primary charging device is used to The surface is uniformly charged and then imagewise exposed to form an electrostatic latent image, the electrostatic latent image is developed into a visible image by a developing machine, and the visible image is transferred onto a sheet by a transfer charger. It is known that the paper is sent to a fixing device to be fixed and the residual toner on the image carrier is cleaned with a cleaner.

In such an image forming apparatus, since the reproducibility of an original having continuous gradation such as a photographic original is poor, the structure shown in FIG. 6 is used to improve the reproducibility. That is,
Image exposure unit 2 and developing unit 3 on the back surface of belt-shaped photoreceptor 1
A screen lamp 6 composed of a screen 4 and a light source 5 is disposed between and, and the surface of the belt-shaped photoconductor 1 uniformly charged by a charger 7 is irradiated with an original image by an image exposure unit 2 to expose the electrostatic latent image. An electrostatic latent image is formed into an image by forming an image, and then forming a screen-shaped non-charged portion by illuminating a screen-shaped optical pattern from the screen lamp 6 from the back surface of the belt-shaped photoreceptor 1. After that, the electrostatic latent image is developed into a visible image by the developing device 3 to improve the reproducibility of an original having continuous gradation.

[0004]

SUMMARY OF THE INVENTION With such a device,
The screen 4 of the screen lamp 6 and the belt-shaped photoreceptor 1
Has a narrow cavity latitude, and the screen lamp 6 needs to be accurately positioned and attached to the belt-shaped photosensitive member 1. Since the installation work of the screen lamp 6 is very troublesome, the assembling work is very troublesome. Or, the replacement work of the screen lamp 6 becomes very troublesome. Therefore, an object of the present invention is to provide a screen lamp mounting structure for an image forming apparatus, which is capable of solving the above-mentioned problems.

[0005]

Image formation in which a screen lamp 28 is attached at an intermediate position between a charging area and a developing area on the back surface side of the belt-shaped photosensitive member 15 with a roller 14 for guiding the belt-shaped photosensitive member 15 as a reference. Screen lamp mounting structure for the device.

As a result, the belt-shaped photosensitive member 15 is moved to the roller 14
Since the screen lamp 28 is mounted on the roller 14 as a reference, the screen lamp 28 can be easily mounted so that the gap between the belt-shaped photosensitive member 15 and the screen lamp 28 becomes a predetermined value. Front vertical plate 1
0 and the rear vertical plate 11 are connected in parallel to each other by a connecting horizontal rod 12 to form a photoconductor support frame 13, and a belt-shaped photoconductor 15 is rotatably attached to the photoconductor support frame 13 along a plurality of rollers 14. A charging device 18, an image exposure unit 19, a developing device 20, a transfer device 21 and the like are sequentially arranged around the belt-shaped photoconductor 15 to form an image forming apparatus, and the charging area and the development in the photoconductor supporting frame 13 are performed. The pair of rollers 14 and 14 are attached to the intermediate position of the region with a narrow attachment pitch, and the screen lamp 2 is provided with the pair of rollers 14 and 14 as a reference.
8 is a screen lamp mounting structure in an image forming apparatus to which 8 is mounted.

As a result, the belt-shaped photosensitive member 15 is irradiated with light by the screen lamp 28 between the pair of rollers 14, 14 having a narrow mounting pitch, so that the belt-shaped photosensitive member 15 may wave (vibrate) in the irradiation area. , The gap between them exceeds the depth of the screen lamp 28,
Part of the pattern does not come off.

[0007]

EXAMPLE As shown in FIG. 5, a front vertical plate 10 and a rear vertical plate 11
Are connected in parallel by a plurality of connecting horizontal rods 12 to form a photoconductor supporting frame 13, and a belt-shaped photoconductor 15 is wound around the photoconductor supporting frame 13 via a plurality of rollers 14.
The photoconductor support frame 13 can be inserted into and pulled out from the apparatus main body by sliding guide rails 16, 16 provided on the left and right along a rail 17 provided on the apparatus main body side. A charger 18, an image exposure unit 19, and
A developing device 20, a transfer device 21, a peeling device 22, a peeling claw 23, a cleaner 24, and the like are provided so as to sequentially face the periphery of the belt-shaped photoconductor 15, and the belt-shaped photoconductor 15 uniformly charged by a charger 18. The surface of the sheet is irradiated with an original image by the image exposure unit 19 to form an electrostatic latent image, the electrostatic latent image is developed into a visible image by the developing machine 20, and the visible image is fed from the paper supply path 25. It is configured such that the transferred paper is transferred by the transfer device 21 and peeled by the peeling claw 23 and then sent by the transport 26 to the fixing device 27 for fixing. A screen lamp 28 is disposed between the image exposing portion 19 and the developing device 20 on the photoconductor supporting frame 13 so as to face the back surface of the belt-shaped photoconductor 15.

As shown in FIGS. 1 to 4, the screen lamp 28 has a lamp housing 3 containing a lamp.
0 is provided with a screen 31 on the upper portion thereof, a lamp body 33 is provided with a cover 32 on the upper portion of the lamp housing 30, and substantially T-shaped side plates 34, 34 are attached to both longitudinal end faces of the lamp body 33. The lamp housing 3 of the main body portion 35 is provided with a resin main body portion 35.
The mounting plate 36 made of metal is attached to the side surface of 0 by thermal crimping, the supporting pin 37 is provided at one end in the longitudinal direction of the mounting plate 36, and the mounting piece 38 is integrally formed at the other end. The left and right side plates 34, 34 are formed to form the front and rear vertical plates 1.
A pair of rollers 14 and 14 which are horizontally extended across 0 and 11 are attached as a reference. That is, the bolt 41 is screwed onto the rear vertical plate 11 through the notch groove 40 in the vertical direction of the support plate 39 to attach the support plate 39 to the inner surface of the rear vertical plate 11, and to support the upper bent piece 39a of the support plate 39. The pin 37 is placed, and the bolt 43 is screwed into the screw hole 44 of the mounting piece 38 from the vertically elongated hole 42 of the front vertical plate 10 to temporarily hold the screen lamp 28, and the support plate 3
9 to move one side plate 34 to the pair of rollers 14
Bushing 14 for rotatably supporting the rear vertical plate 11
A bearing bush 14a for pressing the bolt 41 against a and tightening the bolt 41 and moving the other side in the longitudinal direction of the screen lamp 28 upward to rotatably support the other side plate 34 on the pair of rollers 14 and 14 on the front vertical plate 10. , The bolt 43 is tightened, and the screen lamp 28 is attached with the pair of rollers 14, 14 as a reference. The support plate 39 may be biased upward by a spring or the like.

Because of this, the belt-shaped photoreceptor 15
Rotates while contacting the upper surfaces of the pair of rollers 14, 14,
Since the screen lamp 28 is mounted by being pressed against the lower surfaces of the rotating bushes 14a, 14a that support the pair of rollers 14, 14, the gap (cavity) between the screen lamp 28 and the upper surface of the belt-shaped photosensitive member 15 is always predetermined. In addition to the value, the screen lamp 28 is simply pressed against the lower surface of the rotating bush 14a, which facilitates the mounting work.

Further, since the belt-shaped photoconductor 15 rotates while contacting with the upper surfaces of the pair of rollers 14, 14 having a narrow mounting pitch, when the belt-shaped photoconductor 15 passes a portion facing the screen lamp 28, it is wavy. The belt-shaped photoreceptor 1 by the screen lamp 28 without vibrating.
The flatness of the irradiation surface of No. 5 can be maintained well, the depth of focus of the screen lamp 28 is not exceeded, and the pattern is not partly omitted.

In the above embodiment, the screen lamp 28 is provided between the image exposing section 19 and the developing device 20, but it may be provided between the charging device 18 and the image exposing section 19, or the pair of rollers 14 are provided. May be attached so as not to rotate, and the side plate 34 of the screen lamp 28 may be pressed against the lower surface thereof to be attached.

[0012]

Since the belt-shaped photoconductor 15 is rotated along the roller 14 and the screen lamp 28 is mounted with the roller 14 as a reference, the gap between the belt-shaped photoconductor 15 and the screen lamp 28 is set to a predetermined value. The screen lamp 28 can be easily attached so that Since the belt-shaped photosensitive member 15 is irradiated with light by the screen lamp 28 between the pair of rollers 14 having a narrow mounting pitch, the belt-shaped photosensitive member 15 does not undulate (vibrate) in the irradiation region, and the belt-shaped photosensitive member 15 is not undulated. The gap does not exceed the depth of the screen lamp 28, and the pattern is not partially removed.

[Brief description of drawings]

FIG. 1 is a front view of a screen lamp mounting portion.

FIG. 2 is a left side view of a screen lamp mounting portion.

FIG. 3 is a right side view of a screen lamp mounting portion.

FIG. 4 is an exploded perspective view of a screen lamp mounting portion.

FIG. 5 is a front view of the image forming apparatus.

FIG. 6 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 10 Front Vertical Plate 11 Rear Vertical Plate 12 Connection Horizontal Rod 13 Photoconductor Support Frame 14 Roller 15 Belt-Shaped Photosensitive Body 18 Charger 19 Image Exposure Section 20 Developing Machine 21 Transfer Machine 28 Screen Lamp

Claims (2)

[Claims] 1. A belt-shaped photosensitive member 15 is provided with a plurality of rollers 14.
The belt-shaped photoconductor 15 is provided with a charger 18, an image exposure unit 19, a developing unit 20, and a transfer unit 2 around the belt-shaped photoconductor 15.
In the image forming apparatus in which 1 and the like are sequentially arranged, a screen lamp 28 is provided at an intermediate position between the charging area and the developing area on the back surface side of the belt-shaped photoconductor 15, and the roller 14 that guides the belt-shaped photoconductor 15 is used as a reference. A structure for mounting a screen lamp in an image forming apparatus characterized by being mounted. 2. The front vertical plate 10 and the rear vertical plate 11 are connected in parallel with each other by a connecting horizontal rod 12 to form a photoconductor support frame 13, and the belt-shaped photoconductor 15 is attached to the photoconductor support frame 13.
Is provided rotatably along a plurality of rollers 14, and a charging device 18, an image exposure unit 19, a developing device 20, a transfer device 21 and the like are sequentially arranged around the belt-shaped photoconductor 15 to form an image forming apparatus. The pair of rollers 14 and 14 are mounted at a narrow mounting pitch at an intermediate position between the charging area and the developing area on the photoconductor support frame 13, and the screen lamp 28 is mounted with the pair of rollers 14 and 14 as a reference. A screen lamp mounting structure in a characteristic image forming apparatus.