JP2020148852A - Writing device and image forming apparatus - Google Patents

Abstract

To control the increase and decrease in the amount of air necessary for devices to be cooled to obtain an expected cooling effect.SOLUTION: The present invention is a writing device 30 that is arranged in an image forming unit A having a photoreceptor 20 and an air current generating device 26 generating an air current for cooling devices to be cooled, and for writing an electrostatic latent image in the photoreceptor 20. The writing device is formed with distribution holes 40a and the like to distribute the flow rate of the air current sent from the air current generating device 26 so as to correspond to the devices to be cooled in the image forming unit A.SELECTED DRAWING: Figure 3

Description

The present invention relates to a writing device and an image forming device.

Conventionally, as an image forming unit arranged in an image forming apparatus, there is a structure as shown in FIGS. 11 and 12. FIG. 11 is a perspective view showing a schematic configuration of a conventional image forming unit, and FIG. 12 is a top view thereof. Further, FIG. 13 shows a configuration of a writing device arranged in a conventional image forming unit, in which FIG. 13A is a front view thereof and FIG. 13B is a side view thereof.

The conventional image forming unit B shown in FIGS. 11 and 12 includes a photoconductor 20, a charging device 21, a writing device 50, a developing device 22, a transfer device 23, a cleaning device (not shown), a fixing device 25, and an air flow generator 26. And a waste toner device 29 is provided.

The conventional writing device 50 has an exposure device 32 made of an LEDA (light emitting diode array) and a support member 60 that supports the exposure device 32.
The support member 60 is formed in a downward U-shape that partitions a horizontally long gap γ in front view from the upper surface 32a of the exposure apparatus 32.

The air flow generator 26 cools the developing device 22 by sending and contacting the air flow F3 with the developing device 22 in order to prevent the surface of the toner in the developing device 22 from melting and the toners from aggregating with each other.
Further, a part of the air flow F4 sent out from the air flow generator 26 is divided through the gap γ of the writing device 50 and is flowed to the fixing device 25 or the like to be cooled.

However, in the conventional writing device 50, when the developing device 22 or the like is to be cooled rapidly, even if the air flow sent from the air flow generating device 26 is increased, a part of the increased air flow is generated. The flow is separated through the void γ of the writing device 50.

For this reason, the cooling efficiency is low because the air flow to be brought into contact with the developing device 22 or the like cannot be sufficiently increased, resulting in an increase in the size of the air flow generating device 26, which results in pressure on the layout and the device itself. Invites an increase in size and power consumption.

Patent Document 1 discloses an image forming apparatus that attempts to solve the above-mentioned conventional problems.

The image forming apparatus disclosed in Patent Document 1 has a configuration in which an air flow is formed at least between the exposure apparatus and the developing apparatus for the purpose of lowering the temperature of the image forming unit.

However, the configuration disclosed in Patent Document 1 has an unsolved problem that the cooling air flow cannot be sufficiently controlled to increase or decrease, and the desired cooling effect cannot be obtained.

Therefore, an object of the present invention is to provide a writing device capable of obtaining an desired cooling effect by controlling the increase / decrease of the air flow rate required for the devices to be cooled.

The present invention for solving the above problems is arranged in an image forming unit having a photoconductor and an air flow generator for generating an air flow for cooling the devices to be cooled, and is statically mounted on the photoconductor. In the writing device for writing the electro-occurrence image, a distribution hole is formed for distributing the flow rate of the air flow sent from the air flow generator according to the devices to be cooled in the image forming unit. ing.

According to the present invention, the desired cooling effect can be obtained by controlling the increase / decrease of the air flow rate required for the devices to be cooled.

It is an overview perspective view of the image forming apparatus equipped with the writing apparatus which concerns on 1st Embodiment. It is explanatory drawing which shows the schematic structure of the image formation unit which includes the writing apparatus which concerns on 1st Embodiment. It is a perspective view of the image formation unit which concerns on an example including the writing apparatus of the same above. It is a top view of the image forming unit which concerns on an example including the writing apparatus of the same above. (A) is a front view of the same writing device, and (B) is a side view thereof. It is a front view of the writing apparatus which concerns on 2nd Embodiment. It is a front view of the writing apparatus which concerns on 3rd Embodiment. It is a perspective view of the image formation unit including the writing apparatus which concerns on 4th Embodiment. It is a top view of the image formation unit including the writing apparatus which concerns on 4th Embodiment. It is a perspective view of the image formation unit including the writing apparatus which concerns on 5th Embodiment. It is a perspective view which shows the schematic structure of the conventional image formation unit. It is a top view of the conventional image forming unit. The configuration of the writing device arranged in the conventional image forming unit of the above is shown, (A) is a front view thereof, and (B) is a side view thereof.

The image forming apparatus equipped with the writing apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is an overview perspective view of an image forming apparatus equipped with the writing device according to the first embodiment, and FIG. 2 is an explanatory view showing a schematic configuration of an image forming unit including the writing device according to the first embodiment. is there. Further, FIG. 3 is a perspective view of the image forming unit including the writing device according to the first embodiment, and FIG. 4 is a top view of the image forming unit including the writing device according to the first embodiment. In FIGS. 3 and 4, the same or equivalent ones as described in FIG. 1 and the like are designated by the same reference numerals, duplicated explanations are omitted, and only the differences will be described.

In the image forming apparatus 10 shown in FIG. 1, the document conveying device 11 and the image reading device are placed in the upper part of the housing 12, and inside the housing 12, the image forming unit A1 according to an example, a paper feed table (not shown), and the like Are appropriately arranged.

As shown in FIGS. 2 to 4, the image forming unit A1 according to an example includes a photoconductor 20, a charging device 21, a writing device 30, a developing device 22, a transfer device 23, and a cleaning device (not shown) according to the first embodiment. ), A fixing device 25, an air flow generator 26, and a waste toner device 29.

The photoconductor 20 is formed in a drum shape and is rotated in one direction.
The charging device 21 uniformly charges the photoconductor 20 that is rotated.
The writing device 30 forms an electrostatic latent image based on image data by scanning a laser beam on the surface of the photoconductor 20 charged by the charging device 21.

The developing device 22 develops an electrostatic latent image formed on the photoconductor 20 by exposure by the writing device 30 with toner.
The transfer device 23 transfers the toner image formed on the photoconductor 20 by the development of the developing device 22 onto the printing paper P (see FIG. 2).
The fixing device 25 is for fixing the unfixed image transferred to the printing paper P.
The waste toner device 29 collects used toner.

The air flow generator (hereinafter, referred to as “cooling fan”) 26 has a function of generating and transmitting an air flow to be brought into contact with the devices to be cooled in the image forming unit A1.
In the present embodiment, it is one side AR of the image forming unit A1 and is arranged at a position between the developing device 22 and the photoconductor 20 in the transport direction α of the printing paper P.
The “devices to be cooled” include, for example, a developing device 22 and a fixing device 25.

In other words, the cooling fan 26 shown in the present embodiment is one side AR of the image forming unit A1 and is arranged on the side opposite to the fixing device 25 sandwiching the writing device 30 in the transport direction α.
Then, an air flow is sent from the cooling fan 26 in the width direction β orthogonal to the transport direction α. In other words, an air flow is sent from one side AR of the image forming unit A1 toward the other side AL.

As shown in FIGS. 3 and 4, the writing device 30 according to the first embodiment has a holding body 31 and an exposure device 32 held under the holding body 31.
The holding body 31 has a support member 33 that is horizontally elongated in the width direction β, and a distribution hole forming member 40 that is arranged on one surface 33a of the support member 33 that faces the developing device 22.

FIG. 5A is a front view of the writing device according to the first embodiment, and FIG. 5B is a side view thereof.
The distribution hole forming member 40 is formed in a horizontally long plate shape having the same total length as the support member 33, and is detachably arranged with respect to the support member 33. By making it removable, for example, it can be easily replaced with another distribution hole forming member having a different aperture ratio (described later).

In the distribution hole forming member 40, a plurality of distribution holes 40a to 40e for distributing and circulating the air flow sent from the cooling fan 26 are provided from one side AR in the delivery direction (width direction) β of the air flow. They are arranged at regular intervals toward the lateral AL.
The "constant interval" also includes an interval array that approaches at equal intervals or in a geometric progression from one side AR to the other side AL.

The distribution holes 40a to 40e are formed in a circular shape when viewed from the front, and the air flow sent from the cooling fan 26 is allowed to flow out from the one side 33a facing the developing device 22 to the other side 33b facing the fixing device 25. It is communicated so that it can be done.

In the distribution holes 40a to 40e shown in the present embodiment, the opening ratio of the distribution holes 40a to 40e gradually increases from one side AR in which the cooling fan 26 is arranged toward the other side AL in the air flow delivery direction (width direction) β. Is formed in.
The “opening ratio” is the opening ratio per area of the distribution holes 40a to 40e in the air flow delivery direction (width direction) β of the distribution hole forming member 40.

In the present embodiment, the inner diameter of the largest distribution hole 40e among the plurality of distribution holes 40a to 40e is set to less than 12 mm. That is, the user can insert a finger into the distribution hole to prevent the user from coming into contact with the writing device 30 and other electronic components arranged on the back side. This makes it possible to prevent problems such as electric shock of the user, short circuit of the board, and damage of components.
The inner diameter of less than 12 mm is a value set with reference to the inspection probe B of JIS C 0922. This probe is used as a test finger for various tests.

The reason why the aperture ratio is gradually increased in the air flow delivery direction (width direction) β is because it is considered that a pressure difference is generated from one side AR in which the cooling fan 26 is arranged to the other side AL. Is. Therefore, when such a pressure difference does not matter, it is not necessary to change the aperture ratio as described above.

Further, in the present embodiment, other devices are arranged so as not to block the flow path of the air flow flowing in and out of the distribution hole. As a result, the air flow flowing through the distribution hole is not obstructed, and the cooling effect is not reduced.

The operation of the image forming unit A1 having the above configuration is roughly as follows.
First, the surface of the photoconductor 20 is charged by the charging device 21. A latent image is formed on the surface of the charged photoconductor 20 by irradiating the surface of the photoconductor 20 with a laser beam corresponding to the image data by the writing device 30.

A toner image of the formed latent image is formed (developed) by the developing device 22, and the formed toner image is transferred to the printing paper P conveyed from the paper feed roller 28 by the transfer device 23.

After that, the printing paper P is conveyed toward the fixing device 25, fixed on the printing paper P by pressurizing and heating the toner image, and discharged by the paper ejection roller 27. Then, the cleaning device 24 cleans the surface of the photoconductor 20 and removes excess toner adhering to the surface.

When forming a full-color image, a latent image is formed for each color constituent color (for example, for each of cyan (C), magenta (M), yellow (Y), and black (Bk)). The toner image of the constituent colors is superimposed on the printing paper P and transferred.

The flow state of the air flow in the image forming apparatus 10 provided with the distribution hole forming member 40 having the distribution holes 40a to 40e formed as described above is as follows.
As shown in FIGS. 3 and 4, a part of the air flow F1 sent out by the cooling fan 26 directly reaches the developing device 22 and flows into contact with the developing device 22. Further, a part of the air flow F2 sent out by the cooling fan 26 flows through the distribution holes 40a to 40e of the distribution hole forming member 40 and flows into the fixing device 25.

At this time, by adjusting the opening ratio of the distribution holes 40a to 40e of the distribution hole forming member 40, the air flow rate reaching the fixing device 25 through the distribution holes 40a to 40e and the developing device 22 are reached. It is possible to control the increase / decrease of the air flow rate.

That is, by adjusting the opening ratios of the distribution holes 40a to 40e according to the purpose, the air flow rate reaching the devices to be cooled can be increased or decreased, and a desired cooling effect corresponding to those devices can be obtained. it can. As a result, it is possible to suppress the unnecessary increase in size of the cooling fan 26, the resulting pressure on the layout, and the increase in the power consumption of the cooling fan 26.
Further, by increasing the opening ratio of each distribution hole in the delivery direction of the air flow sent from the cooling fan 26, the devices to be cooled (fixing device 25) are uniformly (evenly) cooled. Can be done.
Further, since the plurality of distribution holes 40a to 40e are arranged at regular intervals from one side AR to the other side AL in the air flow delivery direction (width direction) β, the cooling target (Fixing device 25) can be cooled uniformly (evenly).

FIG. 6 is a front view of the writing device according to the second embodiment. In FIG. 6, the same or equivalent ones as described in FIG. 1 and the like are designated by the same reference numerals, duplicated explanations are omitted, and only the differences will be described.

The writing device 30A according to the second embodiment has an increased number of distribution holes formed in the distribution hole forming member 40.
Specifically, in the air flow delivery direction (width direction) β, nine distribution holes 40a to distribute and distribute the air flow sent from the cooling fan 26 from one side AR to the other side AL. The 40i are arranged at regular intervals from each other.

Each of the distribution holes 40a to 40i is formed in a circular shape when viewed from the front. Further, the fact that the air flow sent from the cooling fan 26 is communicated so as to flow out from the above-mentioned one side 33a facing the developing device 22 to the other side 33b facing the fixing device 25 is as described above. The same is true.

The distribution holes 40a to 40i shown in the present embodiment are also formed so that the opening ratio gradually increases from the one-sided AR in which the cooling fan 26 is arranged toward the other-sided AL.
With such distribution holes 40a to 40g, the flow rate of air reaching the devices to be cooled can be increased or decreased, and a desired cooling effect can be obtained for each device to be cooled.

FIG. 7 is a front view of the writing device according to the third embodiment. In FIG. 7, the same or equivalent ones as described in FIG. 1 and the like are designated by the same reference numerals, duplicated explanations are omitted, and only the differences will be described.

The writing device 30B according to the third embodiment has a reduced opening area of the distribution holes formed in the distribution hole forming member 40.
Specifically, in the width direction β, five distribution holes 40j to 40n having a circular shape in front view for distributing and distributing the air flow sent from the cooling fan 26 from one side AR to the other side AL are connected to each other. They are arranged at regular intervals.

The distribution holes 40j to 40n are communicated so that the air flow sent from the cooling fan 26 can flow out from the one side 33a facing the developing device 22 to the other side 33b facing the fixing device 25. , Similar to those described above.

The distribution holes 40j to 40n shown in the present embodiment are formed so that the opening ratio gradually increases in the air flow delivery direction (width direction) β, but even the largest distribution hole 40n is shown in FIG. The opening ratio is smaller than that of the distribution hole 40e described in the above.

FIG. 8 is a perspective view of the image forming unit including the writing device according to the fourth embodiment, and FIG. 9 is a top view of the image forming unit including the writing device according to the fourth embodiment. In FIGS. 8 and 9, the same or equivalent ones as described in FIG. 1 and the like are designated by the same reference numerals, duplicated explanations are omitted, and only the differences will be described.

In the writing device 30C according to the fourth embodiment, guide members 41a to 41e for guiding the air flow to the distribution holes 40a to 40e are arranged in the vicinity of the distribution holes 40a to 40e equivalent to those described above. are doing.

In the present embodiment, the guide members 41a to 41e are formed so as to protrude within a required angle range along the edges of the distribution holes 40a to 40e.
When laid out, each of the guide members 41a to 41e is formed in a semicircular shape along the edge of the distribution holes 40a to 40e on the other side AL side, and is projected in a side view elliptical shape. As a result, the air flow sent from the cooling fan 26 can be efficiently guided and distributed.
Needless to say, the guide member is not limited to the illustrated shape.

FIG. 10 is a perspective view of an image forming unit including the writing device according to the fifth embodiment.
In the image forming unit A2 according to another example shown in FIG. 10, a cooling fan 26A formed to have a width equal to the width of the writing device 30D according to the fifth embodiment is arranged so as to face the writing device 30D. It is the one with the installed configuration. From the cooling fan 26A, a substantially uniform air flow is sent out over the entire width of the writing device 30D. In this example, the cooling fan 26A is arranged above the developing device 22.

By arranging the cooling fan 26A so as to face the writing device 30D, the pressure change from the one-sided AR to the other-sided AL described in the above-described embodiment is not generated.

That is, the writing device 30D shown in this example is formed by keeping the opening ratio of each distribution hole constant in the sending direction of the air flow sent from the cooling fan 26A. Specifically, the distribution hole forming member 40 is formed with distribution holes 40k having the same aperture ratio between the one side AR and the other side AL.

The distribution holes 40k are circular in front view with the same inner diameter between the one-side AR and the other side AL in the air flow delivery direction (width direction) β, and are arranged at regular intervals from each other.
That is, as shown in this example, in a configuration in which the air pressure does not change between one side AR and the other side AL, the aperture ratio is formed so as to gradually increase in the air flow delivery direction (width direction) β. You don't have to.

A hole opening adjusting member for adjusting the opening area of the distribution hole may be provided.
That is, when it is mounted on a plurality of types of mass-produced machines, it is possible to reduce the cost by attaching a hole adjusting member having a shape corresponding to the desired cooling function of each model to a support member having a basic distribution hole. The cooling function of the model can be achieved.

For example, a holder having a basic distribution hole is molded with resin, and a mylar (opening adjustment member) having a shape that reduces or closes unnecessary distribution holes is attached to realize a desired function at low cost. it can.

Further, in the above-described embodiment, the one in which the distribution holes are formed in a circular shape is illustrated, but it goes without saying that other known shapes may be used.

10 Image forming device 12 Housing 20 Photoconductor 22 Developing device 23 Transfer device 24 Cleaning device 25 Fixing device 26 Cooling fan 27 Paper ejection roller 30 Writing device 32 Exposure device 32a Upper edge surface 33 Support member 33a One side 33b Other side 40a to 40n Distribution holes 41a to 41e Guide member 60 Support member A1 Image forming unit according to one example A2 Image forming unit according to another example AL Other side AR One side

JP-A-2007-140349

Claims (10)

Photoreceptor and
In a writing device for writing an electrostatic latent image on the photoconductor, which is arranged in an image forming unit having an air flow generating device for generating an air flow for cooling the devices to be cooled.
A writing device characterized in that a distribution hole is provided for distributing and distributing the flow rate of the air flow sent from the air flow generator according to the devices to be cooled in the image forming unit. .. The writing according to claim 1, further comprising an exposure apparatus and a holding body for holding the exposure apparatus, and a distribution hole forming member having a distribution hole formed therein is detachably arranged on the holding body. apparatus. The writing device according to claim 1 or 2, wherein a plurality of distribution holes are formed, and the opening ratio of each distribution hole is increased or decreased in the sending direction of the air flow sent from the air flow generator. .. The writing device according to claim 1 or 2, wherein a plurality of distribution holes are formed, and the opening ratio of each distribution hole is constant in the delivery direction of the air flow sent from the air flow generator. .. The writing device according to claim 3 or 4, wherein a plurality of distribution holes are spaced apart from each other. The writing device according to any one of claims 3 to 5, wherein the diameter of the largest distribution hole among the plurality of distribution holes is set to less than 12 mm. The writing device according to any one of claims 1 to 6, wherein other devices are arranged so as not to block the flow path of the air flow flowing in and out of the distribution hole. The writing device according to any one of claims 1 to 7, wherein a guide member for guiding an air flow to the distribution hole is arranged in the vicinity of the distribution hole. The writing device according to any one of claims 1 to 8, wherein an opening adjusting member for increasing or decreasing the opening area of the distribution hole is provided. An image forming apparatus comprising the writing apparatus according to any one of claims 1 to 9.