JPH04260066A - Image forming device - Google Patents

Abstract

PURPOSE:To promote the thermal decomposition of ozone generated when an image is formed, to improve removal efficiency by a filter at the same time and to prolong the life of the filter or to miniaturize the filter and make it light in weight without damaging safety for a human body. CONSTITUTION:A conductor 36 leading to a housing 11 from the neighborhood of a photosensitive body 12 through the upper part of a heating and fixing roller 31 is provided in a device main body 10. Besides, a suction fan 37 which generates an air current toward the outside of the housing 11 is provided in the conductor 36. Simultaneously, the filter 38 is provided in the discharging port of the conductor 36. Then, the load of the filter is reduced and the air current is rectified at the same time by reducing the ozone in the air by the thermal decomposition in the conductor 36. As the result, the removal efficiency of the ozone by the filter 38 is improved.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine, which aims to reduce ozone generated during image formation.

0002

[Prior Art] In conventional image forming apparatuses such as electrophotographic copying machines, ozone [
In order to remove O3], a honeycomb or mesh filter made of an ozone-adsorbing material is installed near the cooling fan, or a filter that decomposes ozone with a catalyst is installed, and the air inside the housing is exhausted through these filters. things were commonly done.

0003

Conventionally, ozone generated within the housing has been removed by exhausting the air inside the housing through a filter.

[0004]However, filters have a certain lifespan, and in order to effectively remove ozone, the filter must be replaced frequently, which reduces operability. There was a problem in that the volume of the device had to be increased, which prevented the device from being made smaller and lighter.

[0005] Furthermore, the wind speed distribution of the airflow passing through the filter is uneven, and the airflow does not pass perpendicularly to the filter.
If the air is rolled up and passes through the filter diagonally, the ozone filtration efficiency will be reduced, and the airflow will not hit the filter uniformly, resulting in uneven ozone concentration depending on the location of the filter. The degree of depletion of ozone also becomes uneven, and in areas where high concentrations of ozone are concentrated, it becomes impossible to filter partially, which has the problem of shortening the life of the filter.

Therefore, in the present invention, the ozone generated inside the housing is reduced to some extent before it passes through the filter, thereby reducing the burden on the filter, extending the life of the filter, making it smaller and lighter, and furthermore, By equalizing the air velocity distribution in the front, the objective is to improve the ozone removal efficiency of the filter and the filter life, reduce the negative effects of ozone on the human body, and provide a highly safe image forming device. do.

[Configuration of the invention]

[0008]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides an image forming apparatus having an image forming means for transferring an image formed on an image carrier to a transfer target member to obtain an image. a housing for housing the means, a corona discharge means for applying an electric charge to the image carrier, a heating fixing means for fixing the powder toner image transferred to the transferred object, and a heating fixing means for fixing the powder toner image transferred to the transfer object, A conductor forming an air path from above the fixing means to the casing; a suction means provided within the conductor for generating an airflow from near the corona discharge means toward the casing; and a suction means provided within the conductor near the outlet of the airflow. and an ozone removing means having a filtration means for filtering ozone.

[0009]

[Operation] The image forming apparatus according to the present invention is constructed as described above, and heat-decomposes ozone [O3] generated within the housing into oxygen [O2] within the conductor before passing through the filter, which is the filtering means. remove to some extent. This already reduces the ozone content in the airflow passing through the filter, reducing the burden on the filter and making it possible to extend the life of the filter or make it smaller and lighter. Furthermore, while the airflow reaches the filter from the vicinity of the corona discharge means, it is guided by a conductor, the wind speed distribution is made uniform, and the airflow passes through the filter almost perpendicularly, so that the ozone filtration efficiency of the filter is improved and the ozone is ejected outward from the image forming apparatus. Ozone emissions can be reduced more efficiently and safety for humans can be improved.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 shows the internal configuration of the entire apparatus. Inside the housing 11 of the apparatus main body 10, which is an image forming apparatus, image forming means such as charging, exposure, development, transfer, peeling, cleaning, neutralization, fixing, etc. 9 is built-in, and a document mounting table 3 on which a document D is set is provided on the upper surface of the casing 11.

The image forming means 9 has the following configuration. That is, a drum-shaped photoreceptor 12, which is an image carrier made of a negative organic photoconductor, is arranged approximately in the center of the housing 11, and a drum-shaped photoreceptor 12, which is an image carrier made of a negative organic photoconductor, is arranged around the photoreceptor 12 along the rotation direction. A charging charger 13 which is a corona discharge means, an exposure section 14a of an exposure device 14, a developing device 16, a transfer charger 17 and a peeling charger 18 which are corona discharge means, and a cleaning device 20, which are well known in the art. Static eliminators 21 are sequentially arranged. Note that a voltage of minus 6 [kV] is applied to both the charging charger 13 and the transfer charger 17, and a voltage of 500 [Hz], ±6 [kV] is applied to the peeling charger 18.
kV] is applied.

Further, on the right side of the housing 10, there are first and second paper feed cassettes 22a for storing paper P, which is an object to be transferred.
, 22b and a manual paper feed tray 22c are provided.

Further, 23 indicates each paper feed cassette 22a, 22b.
Alternatively, from the manual feed tray 22c to the pickup roller 2
This is a paper conveyance path that guides the paper P taken out by 4a, 24b, and 24c through the photoreceptor 12 to the paper discharge tray 26 on the left side of the housing 11. On the upstream side of the photoconductor 12 in the paper conveyance path 23, there are first and second separation rollers 27a and 27b, which align the leading edge of the paper P and synchronize the conveyance of the paper P with the rotational operation of the photoconductor 12. Registration roller pair 2 that transports paper while picking it up
8 is disposed, and on the downstream side there is a heat fixing unit which is a heat fixing means consisting of a conveyor belt 30, a heat roller 31a having a built-in heater lamp 32, and a press roller 31b in rolling contact with the heat roller 31a. A roller 31 and a pair of discharge rollers 29 are arranged further downstream thereof. Heat roller 31
a has a surface temperature of 180± due to the heater lamp 32.
The temperature will be raised to 20 [℃].

Next, reference numeral 34 denotes an ozone removing device which is ozone removing means, and a suction port 36a is formed in the vicinity of the photoreceptor 12, which is near the corona discharge means in the housing 11, and the ozone is removed through the upper part of the heat fixing roller 31. It has a conductor 36 that reaches the side surface of the housing 11. This conductor 36 is made of sheet metal and has good heat conduction.
Furthermore, in order to lengthen the residence time of the air flowing into the inlet 36a, a duct shape is formed with a wide angle toward the side wall of the housing 11, as shown in FIG. There is.

A suction fan 37 is provided within the conductor 36 as a suction means and generates an airflow in the direction of arrow x in FIG. 1 toward the outside of the casing 11 within the conductor 36.

Furthermore, on the side wall of the casing 11, which is the outlet of the air flow and the outlet of the conductor 36, a filter 38 with a honeycomb structure mainly composed of activated carbon is provided as a filtration means to filter ozone. .

Next, the exposure device 14 illuminates the document set on the document table 3 provided on the top surface of the main body 10 with an exposure lamp 41 whose back side is surrounded by a reflector 40.
The light image reflected from the original is transferred to a first reflecting mirror 42,
The light image transmitted through the lens 45 is guided to the lens 45 via the second reflection mirror 43 and the third reflection mirror 44 in order, and then the light image transmitted through the lens 45 is passed to the fourth reflection mirror 46 and the fifth reflection mirror 47.
, a sixth reflecting mirror 48, and a slit glass 49, and are guided to the photoreceptor 12 in this order.

Exposure lamp 4 surrounded by reflector 40
1 and the first reflection mirror 42 are connected to a first carriage (not shown) that is movable back and forth along the lower surface of the document table 3.
The second reflecting mirror 43 and the third reflecting mirror 44 are mounted on a second carriage (not shown) that moves in the same direction at half the speed of the first carriage. The first and second carriages move from left to right in the state shown in FIG. 1 with the carriage shaft and the like as guides, and irradiate light onto the original set on the original platen 3 to expose it. The body 12 is exposed to a light image corresponding to the image of the original by slit exposure.

Next, the operation will be described. When the power source (not shown) is turned on, the heater lamp 32 is turned on by the control device (not shown) to start preheating the human roller 31a, and the suction fan 37 is started by driving the motor (not shown). is rotated, and an airflow in the direction of arrow x is generated within the conductor 36. When the surface temperature of the heat roller 31a reaches 160[° C.], the apparatus body 10 is brought into a ready state.

Next, set the original on the original table 3, set the copy conditions such as the number of copies, paper size, etc. using the numeric keypad or the like on the control panel (not shown), and then press the copy button (not shown). When copying is started by turning on the main body 10 of the apparatus, the main body 10 enters an image forming operation, the exposure lamp 41 is turned on, and the first and second carriages are moved along the document table 3. By this movement, the light is scanned on the original, and the light reflected from the original passes through the lens 4 through the first to third reflection mirrors 42, 43, and 44.
5, and further passes through this lens 45 and is imaged on the photoreceptor 12 via fourth to sixth reflection mirrors 46, 47, 48 and slit glass 49. The surface of the photoreceptor 12 is charged by a charger 13 as it rotates, and an electrostatic latent image of the document is formed by this image formation. This electrostatic latent image is developed by supplying developer with the developing device 16.

On the other hand, at this time, the paper is sent from the first or second paper feed cassette 22a, 22b to between the photoreceptor 12 and the transfer charger 17, and the developer image on the photoreceptor 12 is transferred. Ru. The paper to which this image has been transferred has a release chart.
The photoreceptor drum 12 is peeled off from the photoreceptor 12 by the action of the roller 18, conveyed by the conveyor belt 30, sent to the heat fixing roller 31, where the image is fixed, and ejected to the paper ejection tray 26. , the next copy can be made through the cleaning device 20.

While copying is performed in this manner, ozone is generated near the photoreceptor 12 due to corona discharge by the charging charger 13, transfer charger 17, and peeling charger 18; This ozone-containing air surrounding the photoreceptor 12 rides on the airflow in the direction of arrow x generated by the suction fan 37 and is sucked into the conductor 36 from the suction port 36a. On the other hand, in the conductor 36, a portion corresponding to the upper part of the heat fixing roller 31 is heated to about 50 [°C] due to heat radiation from the heat fixing roller 31, so that the conductor 36
Ozone [O3] drawn into the chamber is easily thermally decomposed into oxygen [O2] as shown in equation 1 below.

[0023]

[Equation 1] Therefore, as shown by the solid line (a) in FIG. 3, the ozone content at point A in the conductor 36 immediately before the filter 38 is approximately 1 [p. p. m], and as shown in (b), the ozone content is about 1.5 [p. p. m ] is the conductor 36
This is reduced to about 2/3 of that of a conventional device without a .

After this, the air inside the conductor 36 has a uniform wind velocity distribution while passing through the conductor 36, rides on the air current in the direction of the arrow x, and the ozone content is almost uniform over the entire surface of the filter 38. It passes vertically through a filter 38, and the ozone is filtered out by the filter.

Note that the ozone removal device 34 in this embodiment
A comparison experiment was conducted on the ozone removal effect between the case where a conductor was used and the conventional case where only a filter was used without using a conductor, and the results shown in FIG. 3 were obtained. That is, as shown by the dotted line (d) in FIG. 3, in the conventional apparatus, the ozone content after ozone removal by the filter is 0.05 [p. p
．． m], whereas the ozone removal device 3 of this embodiment
4, the ozone content at point B after passing through the filter 38 is approximately 0.0, as shown by the solid line (c) in FIG.
3 [p. p. Good results were obtained in that the value was reduced to 2/3 or less of the conventional value. Also, the life of the filter has been improved compared to the conventional one.

As mentioned above, ozone [O3] generated during copying is thermally decomposed into oxygen [O2] while passing through the conductor 36, which is heated by heat radiation from the heat-fixing roller 31, and its concentration increases. is reduced, and thus the filter 38
Since the burden on the filter is reduced, the filter can be made smaller and lighter and have a longer service life without compromising safety to the human body.

On the other hand, air containing ozone is rectified while passing through the conductor 36, making its wind speed distribution uniform, and passing through the filter 38 almost perpendicularly, so that ozone can be filtered efficiently and the ozone concentration can be reduced. Safety is improved because of the ability to further reduce the amount of damage, and the life of the filter can be further extended by making the degree of wear of the filter more uniform.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and can be modified without changing the spirit thereof.
Conductor 3 that thermally decomposes and rectifies the airflow in the front
6, the filter may be of a catalytic type, and the position of the suction means within the conductor is arbitrary.

Furthermore, the material and shape of the conductor are not limited, but
If the conductor is formed into a duct shape with a wider area near the filter as in the embodiment, the volume of the conductor becomes larger, the residence time of air becomes longer, and the thermal decomposition of ozone is further promoted.

[0030]

[Effects of the Invention] As explained above, according to the present invention,
Ozone generated by corona discharge means is guided to the conductor,
By promoting thermal decomposition of ozone while it passes through this area, the ozone concentration can be reduced before it passes through the filter, reducing the burden on the filter, extending the life of the filter or making it more compact without compromising safety to the human body. It becomes possible to reduce the weight and improve maintainability by reducing the frequency of filter replacement. Furthermore, while the air containing ozone passes through a conductor, the airflow is rectified and the wind speed distribution is made uniform, which improves the ozone filtration efficiency of the filter, further improving safety for the human body, and improving the efficiency of the filter. The degree of wear is also made uniform, making it possible to further extend the life of the filter.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing the inside of a device main body according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing an ozone removal device according to an embodiment of the present invention viewed from above.

FIG. 3 is a graph showing the results of an ozone removal experiment using an example of the present invention.

[Explanation of symbols]

10...Device body 12...Photoreceptor 13...Electrical charger 17...Transfer charger 18...Peeling charger 31...Heat roller 34...Ozone removal device 36...Conductor 37...Suction fan 38...filter

Claims (1)

[Claims] 1. An image forming apparatus having an image forming means for transferring an image formed on an image bearing member to a transfer target member to obtain an image, comprising: a housing for housing the image forming means; and a case for applying an electric charge to the image bearing member. a corona discharge means for applying a corona discharge; a heat fixing means for fixing the powder toner image transferred to the transfer target;
A conductor forming an air path from at least the vicinity of the corona discharge means to the housing via above the heat fixing means; a suction means provided within the conductor for generating an airflow from the vicinity of the corona discharge means toward the housing; An image forming apparatus comprising: an ozone removing means having a filtering means provided in the conductor near the outlet of the air flow for filtering ozone.