JP2007065212A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of appropriately deciding the service life of an ozone processing member. <P>SOLUTION: The image forming apparatus, having an ozone removal member 97 decomposing and removing ozone produced during image formation, is equipped with a paper passage counter 103 which counts passing sheets of paper; a control means 100 of detecting the ozone removing member 97 entering replacement period, when the count number of the paper passage counter 103 reaches a specified value; and a display part 104 which performs display urging replacement of the ozone removal member 97 on receiving commands from the control means 100, and is further equipped with a paper type detection sensor 101, which detects the type of transfer paper, and the control means 100 makes the specified value different with the type of paper. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic image forming apparatus, and more particularly to an image forming apparatus characterized by ozone removal technology.

The corona charger, which is the mainstream of the charging system of image forming apparatuses, is provided by applying a high voltage of about 4 kV to 10 kV to a metal wire having a diameter of about 50 to 100 μm, ionizing the atmosphere, and being separated from the corona charger. Charge is applied to the photosensitive member. In the process, unnecessary ozone is generated due to corona discharge. Since a corona charger is also used in the transfer device of the image forming apparatus, ozone is similarly generated.
In recent years, charging devices and transfer devices that generate less ozone, such as roller chargers, have been used. However, if multiple charging devices and transfer devices are provided, such as color image forming devices, the amount of ozone generated Will become more. Since ozone is not preferable for those who work around the image forming apparatus, an ozone processing (decomposing and removing) member represented by an ozone filter has been conventionally mounted. The ozone filter has a reduction in processing capacity according to the amount of ozone adsorbed, and needs to be replaced at a certain period.

Conventionally, when the count value of the sheet passing counter reaches a predetermined value, it is determined that the life of the ozone filter has come to be replaced with a new one. However, it has been found that if the lifetime of the ozone filter is judged uniformly only by the count of the paper passing counter, it does not match the substance. In other words, it was replaced even though it still functioned sufficiently, and on the contrary, although it had reached the end of its life, it was still used.
An object of the present invention is to provide an image forming apparatus capable of accurately determining the lifetime of an ozone treatment member.

In order to achieve the above object, according to a first aspect of the present invention, there is provided an image forming apparatus having an ozone removing member for decomposing and removing ozone generated during image formation, and a paper passing counter for counting the number of paper passing, Control means for detecting that the replacement time of the ozone removal member has been reached when the count number of the counter reaches a predetermined value, and a display unit for displaying a prompt for replacement of the ozone removal member in response to a command from the control means And a paper type detection sensor for detecting the paper type of the transfer paper, wherein the control means varies the predetermined number of counts depending on the paper type detected by the paper type detection sensor.
According to the second aspect of the present invention, in the image forming apparatus having an ozone removing member for decomposing / removing ozone generated at the time of image formation, the sheet passing counter for counting the number of passing sheets and the count number of the sheet passing counter are set to a predetermined value. A control means for detecting that the time for replacement of the ozone removal member has been reached, a display section for displaying a prompt for replacement of the ozone removal member in response to a command from the control means, and detecting the size of the transfer paper A paper size detection sensor that performs the control, and the control unit varies the predetermined value of the count according to the paper size detected by the paper size detection sensor.

  According to the present invention, in an image forming apparatus having an ozone removing member for decomposing / removing ozone generated during image formation, a sheet passing counter for counting the number of sheets to be passed, and a count number of the sheet passing counter are predetermined values (replacement cycle). Control means for detecting that it is time to replace the ozone removal member, and a display unit that displays a prompt to replace the ozone removal member in response to a command from the control means. A paper type detection sensor for detecting the paper type is provided, and the control unit includes a paper size detection sensor for detecting the size of the transfer paper by changing the predetermined value depending on the paper type, and the control unit is configured to detect the paper size. Thus, the lifetime of the ozone treatment member can be accurately determined by making the predetermined value different.

Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a functional block diagram of an image forming apparatus according to an embodiment of the present invention. With a CPU 100 as a center, a paper type detection sensor 101, a paper size detection sensor 102, a paper passing counter 103, and a display unit 104 are provided.
When the count value of the sheet passing counter 103 reaches a predetermined value (replacement cycle count number), the CPU 100 detects that an ozone filter replacement time described later has come, and the display unit 104 receives an instruction from the CPU 100 to A message prompting replacement is displayed. At this time, the CPU 100 changes the predetermined value depending on the paper type detected by the paper type detection sensor 101. Further, the CPU 100 changes the predetermined value depending on the paper size detected by the paper size detection sensor 102. Details thereof will be described later.
FIG. 2 is a mechanical configuration diagram of the image forming apparatus according to the embodiment of the present invention. A charging device 2, an exposure device 3, a developing device 4, a transfer / separation device 5, a cleaning device 6, a charge removal value 7, and the like are provided around a photosensitive drum 1 as an image carrier. Further, a registration roller 8 is provided on the upstream side of the paper conveyance path, and a paper conveyance unit 9 and a fixing device 10 are provided on the downstream side.
The photosensitive drum 1 is rotated in the direction of arrow A by a driving device (not shown). The charging device 2 is a corona charger that uniformly charges the surface of the rotating photosensitive drum 1 by corona discharge. The corona charger applies a high voltage of 4 kV or more to a wire having a diameter of 50 to 100 μm to cause corona discharge. Due to this discharge phenomenon, the atmosphere near the wire is ionized and the surface of the photosensitive drum 1 is ionically charged.
The exposure apparatus 3 forms an electrostatic latent image on the surface of the photosensitive drum 1 by irradiating a laser beam or the like based on an image signal sent from a PC or the like. The electrostatic latent image is conveyed to a developing area which is an area facing the developing device 4 as the photosensitive drum 1 rotates. The developing device 4 attaches charged toner carried on the developing roller to the electrostatic latent image on the photosensitive drum 1 and develops the toner image. The developed toner image is conveyed to a position facing the transfer device 5 as the photosensitive drum 1 rotates.
On the other hand, a transfer sheet P as a transfer material is sent out from a sheet feeding device (not shown) at a predetermined timing and is sandwiched between registration rollers 8. The registration roller 8 sends out the sandwiched transfer paper P at a timing at which the toner image on the photosensitive drum 1 can be superimposed.

The transfer device 5 is disposed below the photosensitive drum 1 so as to face the non-contact surface, and applies a charge having a polarity opposite to that of the toner to the back surface of the transfer paper P conveyed to the transfer region by corona discharge. The corona discharger 5a as a transfer charger for bringing the transfer paper P and the photosensitive drum 1 into close contact with each other and transferring the toner image onto the transfer paper P, and the corona discharge as the separation charger for canceling the charge of the transfer paper P by corona discharge. It consists of an electric appliance 5b.
The photosensitive drum 1 that has passed through the region facing the transfer device 5 is mechanically scraped and removed by the cleaning blade of the cleaning device 6 after the residual toner remaining on the surface thereof. And is prepared for the next image forming process.
The paper transport unit 9 includes a drive roller 91 that is rotated by a drive unit (not shown), a driven roller 92, a paper transport belt 93, a transport tank 94 that serves as a path for air flow to be sucked, a suction device 95, a paper transport guide plate 96, and an ozone filter. 97 and so on. Due to the suction force of the suction device 95, the transfer paper P sent from the transfer device 5 onto the paper transport belt 93 is sucked toward the surface of the paper transport belt 93, moves with the paper transport belt 93, and moves to the fixing device 10. It is conveyed toward.
The fixing device 10 includes a fixing roller 10a having a heater and a pressure roller 10b that rotates while contacting the fixing roller 10a with a predetermined pressure. The transfer paper P sent from the paper transport belt 93 is placed between the two rollers. Sandwich. When the transfer paper P is sandwiched in this way, the toner image adhering to the surface is fixed on the transfer paper P by a synergistic action of heating and pressurization. The transfer paper P on which the toner image is fixed is discharged out of the apparatus by a paper discharge device composed of a transport roller pair 11a and a paper discharge roller pair 11b.

FIG. 3 is a perspective view of the paper transport unit, and FIG. 4 is a perspective view schematically showing how ozone is removed in the paper transport unit. As shown in FIG. 3, a plurality of driving rollers 91, driven rollers 92, paper transport belts 93, transport tanks 94, and suction devices 95 are arranged in the body width direction.
As shown in FIG. 4, the paper transport belt 93 has a large number of minute through holes, and is rotated by the drive roller 91 in the direction of arrow B in the figure while being stretched by the drive roller 91 and the driven roller 92. It moves endlessly by driving. The suction device 95 sucks air from the back surface of the paper transport belt 93 through the transport tank 94 to generate suction force at a large number of minute through holes provided in the paper transport belt 93. As described above, the transfer paper P is sucked to the paper transport belt 93 by this suction force.
The suction device 95 also has a function of discharging heat generated by the fixing device 10 and ozone generated by corona discharge of a plurality of corona chargers (charging device 2 and transfer / separation device 5). As indicated by the arrows in the figure, the internal atmosphere (heat and ozone) is a suction device 95 through a plurality of minute through holes provided in the conveyance guide 96 through a conveyance tank 94 in addition to a plurality of minute through holes in the conveyance belt 93. And is discharged out of the apparatus after passing through an ozone filter 97 provided at the outlet of the transfer tank 94.
Ozone has a strong oxidizing power, greatly affects the deterioration of rubber and metal and photoconductors, and the user feels odor and irritation in the nose and throat. It is necessary to discharge. Further, since the ozone filter 97 has a reduced processing (ozone decomposition / removal) capability according to the amount of ozone adsorbed, it needs to be periodically replaced.

<Example 1>
In the first embodiment, the CPU 100 changes the predetermined value (replacement cycle count) of the paper passing counter 103 for replacing the ozone filter 97 according to the paper type detected by the paper type detection sensor 101.
FIG. 5 is a characteristic diagram of the first embodiment. Specifically, it shows the relationship between the number of sheets of transfer paper with different paper types and the amount of ozone discharged. It is assumed that the ozone filter 97 is replaced when the ozone discharge amount becomes 0.04 ppm. It can be seen that the replacement cycle count of the paper passing counter 103 until the replacement is approximately three times as large as 20000 for plain paper and 60000 for recycled paper.
From the above, when recycled paper is passed, the replacement frequency count of the ozone filter 97 is set to three times that of plain paper, so that the ozone filter 97 can be replaced many times in an environment where recycled paper is mainly used. The ozone filter 97 can be used efficiently until the lifetime is reached.
The difference in ozone discharge amount depending on the type of transfer paper in the experiment of Example 1 is considered because recycled paper contains more components that adsorb or decompose ozone added during paper manufacture.

<Example 2>
In the second embodiment, the CPU 100 changes the predetermined value (replacement cycle count) of the paper passing counter 103 that replaces the ozone filter 97 according to the paper size detected by the paper size detection sensor 102.
FIG. 6 is a characteristic diagram of the second embodiment. Specifically, it shows the relationship between the number of passing sheets of transfer paper of different sizes and the amount of ozone emission obtained in advance by experiments. It is assumed that the ozone filter 97 is replaced when the ozone discharge amount becomes 0.04 ppm. It can be seen that the number of replacement cycle counts until the replacement is approximately twice as large as 20000 for wide paper corresponding to the A1 width and 10,000 for narrow paper corresponding to the A3 width.
From the above, when the narrow paper corresponding to the A3 width is passed, the replacement period count number of the ozone filter 97 is ½ times the wide paper corresponding to the A1 width (the wide paper corresponding to the A1 width is passed). When paper is used, the ozone filter 97 replacement cycle count is twice that of the wide paper corresponding to the A3 width). In an environment where paper is mainly used, the ozone filter 97 is replaced more frequently than the narrow paper. The ozone filter 97 can be efficiently used until the lifetime is reached.
The difference in ozone discharge amount according to the paper width in the experiment of Example 2 is that the transfer paper having the ozone processing capacity is above the ozone generation source having the same width as the maximum width of the transfer charger 5a and separation charger 5b. It is thought that it depends on whether it passes.
In addition, since the minute through-holes provided in the paper transport belt 93 and the paper transport guide plate 96 are the only in-machine atmosphere discharge path, the ozone treatment capability is also provided for ozone generated by corona discharge of the charging device 2. It is thought that it depends on how wide a certain transfer paper passes over the minute through hole.
If the path for exhausting ozone generated in the machine to the outside of the machine and the transfer path of the transfer paper are crossed multiple times, the atmosphere in the machine with a high ozone concentration is brought into contact with the transfer paper having ozone adsorption ability multiple times. In addition, the ozone filter 97 can be used efficiently, and the replacement period of the ozone filter 97 can be lengthened.

1 is a functional block diagram of an image forming apparatus according to an embodiment of the present invention. 1 is a mechanical configuration diagram of an image forming apparatus according to an embodiment of the present invention. FIG. 6 is a perspective view of a paper transport unit portion. It is a see-through | perspective perspective view which shows a mode that ozone is removed in a paper conveyance unit. 2 is a characteristic diagram of Example 1. FIG. 6 is a characteristic diagram of Example 2. FIG.

Explanation of symbols

97 Ozone filter (ozone removal member)
100 CPU (control means)
101 Paper type detection sensor 102 Paper size detection sensor 103 Paper feed counter 104 Display unit

Claims (2)

  In an image forming apparatus having an ozone removing member for decomposing / removing ozone generated during image formation, a paper passing counter for counting the number of paper passing, and when the count of the paper passing counter reaches a predetermined value, A control means for detecting that the replacement time has been reached, a display section for receiving a command from the control means to prompt the replacement of the ozone removal member, a paper type detection sensor for detecting the paper type of the transfer paper, The image forming apparatus is characterized in that the control means varies the predetermined value of the count according to the paper type detected by the paper type detection sensor.   In an image forming apparatus having an ozone removing member for decomposing / removing ozone generated during image formation, a paper passing counter for counting the number of paper passing, and when the count of the paper passing counter reaches a predetermined value, A control means for detecting that the replacement time has been reached, a display section for displaying a prompt for replacement of the ozone removing member in response to a command from the control means, and a paper size detection sensor for detecting the size of the transfer paper. The image forming apparatus is characterized in that the control unit varies the predetermined value of the count according to the paper size detected by the paper size intelligent sensor.

Images