JP2008102412A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To bring a cleaning web into uniform contact with the surface of a body to be cleaned, by using a non-contact optical detecting means for detecting the outside diameter of a cleaning web without damaging the cleaning web. <P>SOLUTION: An optical detecting means disposed so as not to touch the cleaning web on a feed-out roller or wind roller is used as a detecting means. A control means determines a drive period for the feed-out roller or wind roller based on an output from the optical detecting means, thereby controlling the fed-out out amount or wound amount of the cleaning web. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a printer or a copying machine, and more particularly to an image forming apparatus provided with a mechanism for cleaning an object to be cleaned by a winding web that can be wound.

  A cleaning web that comes into contact with the surface of the object to be cleaned; a feed shaft that feeds the cleaning web; a take-up shaft that winds the cleaning web; and a detecting means that detects the outer diameter of the feed shaft or the take-up shaft. Japanese Patent Application Laid-Open No. 2004-228561 describes a web cleaning device that controls the amount of web feeding or the amount of winding of a cleaning web according to a signal from a detection means.

JP 58-182673 A

  In the configuration described in Patent Document 1, since the roller constituting the detection means is always pressed against the cleaning web, the web surface is wavy, the contact state with the surface of the object to be cleaned becomes unstable, and cleaning is performed. There is a disadvantage that unevenness occurs.

  The present invention detects a cleaning web that comes into contact with the surface of the object to be cleaned, a feed roller that feeds the cleaning web, a take-up roller that winds the cleaning web, and an outer diameter of the feed roller or the take-up roller. In the image forming apparatus, comprising: a detection unit; and a control unit that controls a feeding amount or a winding amount of the cleaning web based on an output of the detection unit. The detection unit is arranged on the feeding roller or the winding roller. An optical detection means provided in non-contact with the cleaning web, and the control means determines a driving cycle of the feed roller or the take-up roller based on an output of the optical detection means, and sends out the cleaning web. It is characterized by controlling the amount or winding amount.

  According to the present invention, since the non-contact optical detection means is used to detect the outer diameter of the cleaning web, the cleaning web can be uniformly brought into contact with the surface of the object to be cleaned without damaging the cleaning web.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  First, the overall configuration of a laser beam printer using an electrophotographic system to which the present invention is applied will be described with reference to FIG.

  In FIG. 2, the photosensitive drum 1 of the laser beam printer P starts to rotate in the arrow direction based on the printing operation start signal from the controller C. The photosensitive drum 1 rotates at a speed corresponding to the printing speed of the printer P and continues to rotate until the printing operation is completed. When the photosensitive drum 1 starts to rotate, a high voltage is applied to the corona charger 2 and, for example, a positive charge is uniformly charged on the surface of the photosensitive drum 1.

  The photosensitive region charged by the corona charger 2 is image-exposed with a beam from the exposure device 3, and an electrostatic latent image is formed on the surface of the photosensitive drum 1. When the photosensitive region holding the electrostatic latent image reaches a position facing the developing device 4, toner is supplied to the electrostatic latent image, and for example, a positive portion is removed from the portion on the photosensitive drum 1 where the charge is lost by beam irradiation. The charged toner is attracted by electrostatic force to form a toner image on the photosensitive drum 1.

  The web paper W set on the paper hopper 5 is synchronized with the timing at which the toner image formed on the photoconductive drum 1 reaches the transfer position by the web conveying roller 6. It is conveyed toward the middle.

  The toner image formed on the photosensitive drum 1 is transferred onto the web paper W by the action of the transfer unit 7 that applies a charge having a polarity opposite to that of the toner image to the back side of the web paper W.

  Thus, the web paper W set in the paper hopper 5 is conveyed to the fixing device 10 via the web conveyance roller 6, the transfer unit 7, the web conveyance suction belt 8 and the buffer plate 9. The web paper W reaching the fixing device 10 is preheated from the back side by a preheating plate 11 incorporating a heater (not shown), and then formed by a heating roller 13 and a pressure roller 14 incorporating a heater lamp 12. The toner image is nipped and conveyed while being heated and pressurized at the nip portion, and the toner image is melted and fixed on the web paper W.

  The web paper W sent out by the heating roller 13 and the pressure roller 14 is sent out of the machine by the web paper feed roller 15 and subjected to processing such as cutting by a post-processing device (not shown).

  On the other hand, the photoreceptor area that has passed the transfer position is prepared for the next printing operation through the static eliminator 16, the static eliminator lamp 17, the cleaning device 18, the pre-charger 19, and the static eliminator lamp 20. Here, the static eliminator 16 is used to pull back a portion where the surface potential polarity of the photoconductor has been reversed from positive to negative by the action of the transfer device 7, and the photoconductor pulled back to the positive polarity is The electricity is once removed by the electricity removing lamp 17 and cleaned by the cleaning device 18.

  Prior to the charging step in the corona charger 2, the photosensitive region that has passed the cleaning device 18 is charged and discharged again by the pre-charger 19 and the charge-removing lamp 20, and the condition of the surface of the photosensitive member is adjusted.

  In FIG. 2, reference numeral 21 denotes an operation panel for displaying information based on the state of the printer P during a printing operation and for setting printing conditions. Further, the buffer plate 9 described above absorbs the slack and tension generated on the web paper W when a web paper W has a transport speed difference between the web transport suction belt 8 and the fixing rollers 13 and 14. belongs to. Reference numeral 22 denotes a cleaning web which is provided so as to be able to come into contact with the surface of the heating roller 13 and is supported by the feeding roller 23 and the winding roller 24 so as to be rewound. It is for performing the application | coating of the mold release agent to.

  Next, based on FIG. 1, the structure of the winding mechanism of a cleaning web is demonstrated.

  In FIG. 1, a driving motor 26 is connected to the winding roller 24 of the cleaning web 22, and the winding roller 24 is driven by a driving pulse from a driving circuit 28. As the drive motor 26, a stepping motor is usually used.

  The optical sensor 25 as a detecting means for detecting the outer diameter of the take-up roller 24 is provided so as not to contact the cleaning web 22 on the take-up roller 24, and the take-up roller via the control circuit 27 and the drive circuit 28. Drive pulses corresponding to the outer diameter of 24 are generated.

  For example, when the detected outer diameter at the start end is 50 mm, the length of the cleaning web 22 wound up in one round is about 160 mm. Assuming that the number of pulses of the drive motor 26 for rotating the winding roller 24 once is 20000 pulses, and the drive pulse period at this time is 500 ms, the occurrence of offset of the heating roller 13 can be prevented. 160 mm ÷ (500 ms × 20000) ≈ The cleaning web 22 is wound up at a winding speed of 0.016 mm / s.

  Here, when the detected outer diameter is 60 mm, the drive pulse period may be 600 ms. That is, when the outer diameter is 60 mm, since one round is about 190 mm, 190 mm ÷ (600 ms × 20000) ≈0.016 mm / s, and the cleaning web 22 is wound at a constant speed.

  As the outer diameter of the take-up roller 24 increases, the drive pulse period of the drive motor 26 is extended, so that the cleaning web 22 can always be taken up at a constant speed without winding the cleaning web 22 more than necessary. As a result, the service life can be extended.

  In the above description, the description is based on the configuration for detecting the outer diameter of the take-up roller 24. However, the outer diameter of the feed roller 23 is detected, and the take-up control of the cleaning web 22 is performed based on the detected outer diameter. May be.

  In that case, the remaining diameter (remaining length) of the cleaning web 22 is calculated by detecting the outer diameter of the feed roller 23, and the remaining length is subtracted from the entire length of the cleaning web 22, thereby cleaning the web 22. Use length is required. The outer diameter of the winding roller 24 can be calculated from the thickness of the cleaning web 22, the length used, and the core diameter of the winding roller 24.

  Further, according to the present invention, since the absolute value of the outer diameter of the take-up roller 24 can be continuously detected, for example, when the customer replaces the cleaning web 22, it can be removed and replaced before the end of its life. Even when the cleaning web 22 in use is loaded, the winding speed of the cleaning web 22 can always be made constant, the occurrence of the offset of the heating roller 13 can be prevented, and the cleaning web 22 It is possible to extend the service life, and as a result, it is possible to provide an apparatus with high quality and improved productivity and operability.

  In addition, when the printing speed of the printer is increased or the dimensional relationship of the cleaning web is changed, the necessary cleaning web winding speed can be maintained without changing the main configuration. This can be applied by changing the calculation formula and changing the pulse period of the drive motor.

It is a schematic block diagram of the cleaning web winding mechanism which shows one Example of this invention. 1 is a schematic configuration diagram of an image forming apparatus.

Explanation of symbols

13 Heating roller (object to be cleaned)
DESCRIPTION OF SYMBOLS 22 Cleaning web 23 Sending roller 24 Winding roller 25 Detection means 26 Drive motor 27 Control circuit 28 Drive circuit W Web paper

Claims (1)

A cleaning web that comes into contact with the surface of the object to be cleaned; a feed roller that feeds the cleaning web; a take-up roller that winds up the cleaning web; and a detection means that detects an outer diameter of the feed roller or the take-up roller; And an image forming apparatus including a control unit configured to control a feeding amount or a winding amount of the cleaning web on the basis of an output of the detecting unit. The optical detection means is provided in a non-contact manner, and the control means determines a driving cycle of the feed roller or the take-up roller based on an output of the optical detection means, and feeds or winds the cleaning web. An image forming apparatus characterized by controlling the amount.

Images