JPH0218236A - Original conveying device - Google Patents

Abstract

PURPOSE:To maintain a belt in a normally clean state irrespective of a kind of an original without exerting a surplus load on a belt for conveying an original by providing a control means which is adapted to control so that a cleaning means is brought into contact with the belt for conveying an original based on a detecting signal from a stain detecting means. CONSTITUTION:When, during movement of a belt 22 for conveying an original, the stain of the belt 22 is detected by a stain detecting means 1a, based on a detecting signal therefrom, a control means X excites a solenoid 31 of a drive device 3 in a cleaning means (cleaning roller) 2. The control means rotates a lever 32 against the force of a spring 33, and brings the cleaning means 2, mounted to the tip of a lever 32, into pressure contact with the belt 22 for conveying an original. With this state, the stain of the belt 22 for conveying an original under movement is removed by the cleaning means 2. When the stain is decreased to a value lower than a given value, the control means X demagnetizes a solenoid 31, separates the cleaning means 2 from the belt 22 through the restoration force of the spring 33, releases a load on the belt 22, and maintains the belt 22 at a normally clean state.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention C relates to a document conveying device installed in an image forming apparatus such as a copying machine. The present invention relates to a document conveying device that has the function of

(B) Conventional Technology Conventionally, as shown in FIG. 6, a document conveying device 20' carries an original [P] on a paper feed tray 21 by a document conveying belt (hereinafter referred to as a belt) 22, and transfers it to a platen 20 of a copying machine M. It is configured to be placed on top. In addition, the belt 22 includes
A cleaning roller 30 is always in pressure contact and cleans dirt on the belt 22 when the belt 22 rotates.

→ Problems to be Solved by the Invention However, in a configuration in which the cleaning roller 30 is always in pressure contact with the belt 22, there is a drawback that the load applied to the belt 22 becomes large.

As a countermeasure against this problem, there is a method of automatically cleaning the belt 22 by moving the cleaning roller 30 toward and away from the belt 22 at regular intervals. However, the document conveying device handles a wide variety of documents, and the degree of dirt on the belt 22 varies depending on the type of documents. For example, there is a significant difference in the degree of dirt between a pencil original and a printed original. Therefore, if the number of cleaning cycles is set according to the case where the cleaning roller 30 is most likely to get dirty, the cleaning roller 30 will operate more frequently. As a result, the user has to wait when using the machine, resulting in a loss of time. On the other hand, if you match it with the printed original, there is a problem that it will become smudged when you print the pencil original or the second original.

Therefore, the present invention automatically reads the degree of contamination of the original FjlIWI conveyor belt, and only when the contamination exceeds a certain level,
The cleaning means is a document transport bell! It is an object of the present invention to provide a configuration in which the device is brought into pressure contact with the device, thereby solving the above-mentioned problems.

(b) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances. For example, as shown in FIG.
22) in a document transport device (20 m) comprising:
A dirt detection means (1a) for detecting dirt on the document conveyance belt (22), and a contamination detection means (1a) for detecting contamination on the document conveyance belt (22); A cleaning means (2) for cleaning the conveying belt (22) and a cleaning means (2) are controlled to approach and separate from the original feeding belt (22) based on the dirt detection by the dirt detecting means (1a). The invention is characterized by comprising means (X) for doing so.

(e) Effect Based on the above configuration, the original T14vR sending bell! -(22)
When the belt (22) moves, dirt on the belt (22) is detected by the dirt detection means (1a). And dirt detection means (
The cleaning means (2) is controlled based on the dirt detection in 1a), and when the dirt on the document stirring belt (22) reaches a predetermined level or more, the cleaning means (2) approaches and separates from the document conveying belt (22). to remove dirt. Further, when the dirt is below a predetermined level, the cleaning means (2) is separated from the document conveying belt (22) so as not to be a burden on the belt (22).

Note that the above-mentioned symbols in parentheses do not limit equivalent configurations.

(F) Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the document conveyance device J 20a of this embodiment includes a sensor 1a that reads dirt on the belt 22, and a cleaning device that is supported so as to be able to move toward and away from the belt 22 and that cleans the belt 22. It includes a roller 2 and a driving device 3 (FIG. 3) that operates the cleaning roller 2 to bring it into contact with and away from the belt 22.

In FIG. 1, the same reference numerals as in FIG. 6 indicate the same elements.

The belt roller 23 is located inside the belt 22 and applies a conveying force to the belt 22. Cleaning roller 2 is belt 2
It is supported so as to be able to move toward and away from the belt roller 23 with 2 in between. A reflective sensor 1a is provided opposite the belt roller 23. The sensor 1a is located on the extension line of the presser roller 26 in the belt movement direction (see FIG. 2). In other words, it is located at the position where it is most likely to get dirty, and constantly monitors the degree of dirt on the belt.

FIG. 3 shows the driving device 3 for the cleaning roller 2. As shown in FIG.

The drive device 3 is made up of a solenoid 31, a lever 32, and a spring 33. The roller 2 is rotatably supported at one end of the lever 32. The lever 32 is normally tensioned by a spring 33 and moves the roller 2 away from the belt 22. The plunger of the solenoid 31 is the lever 32
is rotatably connected to.

When the solenoid 31 is activated, the cleaning roller 2 is moved to the belt 2.
2. At the same time, gear 29 coaxial with roller 2 engages gear 27 coaxial with roller 23, as shown in FIG. Then, the belt motor 5 is started.

The cleaning roller 2 is located at a position corresponding to at least the presser roller 26 and the center rib 51. Since an adhesive sheet is pasted on the outer periphery of the cleaning roller 2, dirt on the belt 22 is transferred to the adhesive sheet and removed.

The original conveyance device fil 20m includes a cleaning roller control means
is programmed.

FIG. 4 shows the relationship between the output level of the sensor 1a constituting the dirt detection means and the dirt on the belt 22.

When the belt 22 is not dirty, the reflected light is strong and a high voltage is output, and as the dirt progresses, the voltage decreases.

The sensor 1a detects dirt on the belt 22, and if the dirt is above a certain level, it indicates that normal operation is not in progress (copying is not in progress, the original fat P is not on the platen 25, and the document feeder 20a is closed). After confirming that the machine is in a clean state, the solenoid 31 is turned on to start automatic cleaning. The presence or absence of a document can be checked using an open/close switch or the like to see if the original v4ts sending device 20a is opened or closed after copying in the book mode.

Furthermore, when the sensor 1a detects that the level of dirt is below a certain level, the motor 5 is stopped, the solenoid 31 is turned off, and the cleaning roller 2 is activated.・It is separated from 22 and returns to its original position, completing the cleaning.

Next, a second embodiment will be described in which a drum potential sensor 1b is provided in place of the sensor 1a constituting the dirt detection means described above.

In this embodiment, as shown in FIG. 1, a drum potential sensor 1b is arranged facing the photosensitive drum 13 of the copying machine M, and the drum potential sensor 1b is arranged to face the photosensitive drum 13 of the copying machine M. When a signal is sent to the copying machine M, the copying machine M scans the optical system 10 consisting of a mirror 11, a halogen lamp 12, etc., irradiates the belt 22 with a beam of light, and sends a bell! - Send the image on the surface of 22 to the photosensitive drum 13. Therefore, the potential of the drum 13 is measured by the drum potential sensor 1b, and the density of the belt 22, that is, the dirt is detected.If the density is above a certain level, the original 114 conveying device 1120m performs automatic cleaning as in the above embodiment. Start. Automatic cleaning is
This is the same as the first embodiment described above.

Further, a third embodiment in which a detection lens and a detection element are provided as dirt detection means will be described.

In this embodiment, as shown in FIG.
A detection lens 15 and a detection element 16 consisting of a CCD (solid-state image sensor) are arranged in the optical path between the mirrors 11 and 11 in the optical system 10 of the optical system 10, and the mirror 11 is detected at a constant count from the document feeder W20a. A reflected light image of the belt 22 created by scanning with an optical system 10 comprising a halogen lamp 12 and the like is focused on a detection element 16 through a detection lens 15, and the density of the belt 22 is detected.

If the highest density part of the image formed on the detection element 16 is above a certain level, the optical system 10 sends a signal to the document feeder 20a, and the original torn feeder 20g automatically cleans the belt as described above. Start.

(g) As described in detail, according to the present invention, the dirt detection means;
The cleaning means and the means for controlling the cleaning means to approach and separate from the document conveyance belt based on the detection ζ of the dirt detection means are provided, so that when the document conveyance belt becomes dirty for a certain period of time or more, the belt 1- If the original 114m transport belt is not very dirty, no load is placed on the belt, and the cleaning means is activated only if the belt becomes very dirty, regardless of the type of document. , it is possible to always maintain the document conveying belt in a clean state without applying an extra load.

[Brief explanation of the drawing]

FIG. 1 is a side view of a document conveying device installed in a copying machine according to an embodiment of the present invention, FIG. 2 is a plan view showing the arrangement of cleaning rollers, FIG. 3 is a side view thereof, and FIG. 4 is an original. A graph showing the relationship between the degree of dirt on the glass agitation belt and the output level of the sensor, FIG. 5 is a side view of a document conveying device installed in a copying machine according to another embodiment, and FIG. 6 is a diagram showing the conventional original. FIG. 2 is a side view showing the FJI transport device. 1B... Dirt detection means (sensor) 2A cleaning means (cleaning roller) 20a/Document transport device
22...Original T14 conveyor belt X-controlling means (cleaning roller control means)

Claims (1)

[Scope of Claims] 1. A document conveying device comprising a document conveying belt, comprising: a dirt detection means for detecting dirt on the document conveying belt; and a dirt detecting means for detecting dirt on the document conveying belt; A document conveyance device comprising: a cleaning device for cleaning a belt; and a device for controlling the cleaning device to move toward and away from the document conveyance belt based on the dirt detection by the dirt detection device. .