JPH04115663A - Picture forming device - Google Patents

Abstract

PURPOSE:To early and precisely detect the staining of a reflecting part for shading correction by comparing and discriminating reflected light from a light reflecting part for shading correction when a light transmitting body is made to be led/leave to/from an optical path. CONSTITUTION:Light is emitted from a light source 6 to an original pressing roller 4, received by a photoelectric conversion element 10, transmitted to a scanner circuit 11 and cones to be the first data for shading correction, and since the image forming position of the reflected light is deviated from the light receiving face of the photoelectric conversion element 10, the effect of the staining of the original pressing roller 4 does not appear. Next, a transparent glass plate 12 is returned to the first position deviated from an optical path S, the original pressing roller 4 is irradiated by the light from the light source 6, the second data for shading correcting are prepared, and since the reflected light is image-formed on the light receiving face of the photoelectric conversion element 10, the effect of the staining of the original pressing roller 4 appears in the data. After that, the first and the second data for shading correcting are compared and the staining of the original pressing roller 4 is judged. Thus, the staining of a reflecting part for shading correcting can be detected early and precisely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus such as a copying machine or a facsimile machine.

[Prior Art] In a conventional copying machine, shading correction data is created prior to reading image data from a document in order to correct non-uniform illuminance on the surface of the document in the main scanning direction.

In a copying machine that uses a fixed original exposure method, a light source illuminates a white plate placed on the front glass, and illuminance data (shading correction data) for the main scanning direction is created based on the reflected light. ing.

In addition, in an original moving type exposure type copying machine, light is irradiated from a light source onto an original pressing roller disposed above an original reading position, and shading correction data is created based on the reflected light.

[Problem to be Solved by the Invention] In any of the copying machines described above, if the white plate or the reflective surface of the document pressing roller becomes dirty, the influence of that dirt will appear in the shading correction data, so accurate shading correction cannot be performed. become unable to do so. For this reason, if the white plate or the reflective surface of the document suppression roller becomes dirty, stains such as vertical streaks will appear on the copied copy.

Conventionally, the operator determines whether the white plate or the reflective surface of the original suppression roller is dirty based on the appearance of vertical streaks on the copied copy.

For this reason, it is difficult to quickly and accurately determine whether the white plate or the reflective surface of the document suppression roller is dirty.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus that can quickly and accurately detect that a reflecting part for nading correction, such as a white plate or a document pressing roller, is dirty.

[Means for Solving the Problems] An image forming apparatus according to the present invention includes a light beam emitted from a light source and reflected by a shading correction light reflecting section in an optical path until the light is focused on a photoelectric conversion means by a focusing lens. , a light-transmitting body for shifting the imaging position disposed so as to be able to enter and exit the optical path; a driving device for moving the transparent body for adjusting the imaging position into and out of the optical path; a first illuminance data creation means for causing the shading correction light reflection section to be irradiated with light from a light source and for storing first illuminance data in the main scanning direction in the storage means based on the output of the photoelectric conversion means on which the reflected light is incident; The light body is moved out of the optical path, the light reflecting section for shading correction is irradiated with light from the light source, and the second illuminance data in the main scanning direction is stored in the storage means based on the output of the photoelectric conversion means on which the reflected light is incident. a second illuminance data creation means, a determining means for determining whether the light reflecting section for shading correction is dirty and 0 or not by comparing the first illuminance data and the second illuminance data; The present invention is characterized in that it includes a notification means that notifies the user when it is determined that the light reflecting portion has become dirty.

[Operation of the invention] Prior to reading image data from a document, a light transmitting body is introduced into the optical path, light is irradiated from the light source to the shading correction light reflection section, and the reflected light is incident on the photoelectric conversion means. Based on the output, first illuminance data in the main scanning direction is stored in the storage means.

Further, the transparent body is moved out of the optical path, light is irradiated from the light source to the shading correction light reflection section, and second illuminance data in the main scanning direction is stored based on the output of the photoelectric conversion means into which the reflected light is incident. stored in the means.

Then, by comparing the first illuminance data and the second illuminance data, it is determined whether or not the shading correction light reflection section is dirty, and when it is determined that the shading correction light reflection section is dirty. Then, a notification to that effect is made by the notification means.

[Embodiment] Hereinafter, an embodiment in which the present invention is applied to a copying machine using an original moving type exposure method will be described with reference to the drawings.

FIG. 1 and FIG. 2 schematically show the structure of a document supplying section and an exposure section of a copying machine using a moving document type exposure method.

A document (as shown) is sent to an image reading position on a contact lens 3 by carry-in rollers 1 and 2, advances over the contact lens 3 while being pressed onto the contact lens 3 by a document pressing roller 4, and is transferred by a carry-out roller 5. It will be carried out. Exposure is performed while the document passes through the image reading position on the contact lens 3. That is, light is irradiated from the light source 6 onto the original, and the reflected light from the original is reflected by the mirrors 7 and 8 and is focused by the condenser lens 9 onto the light receiving surface of the photoelectric conversion element 10. The output of the photoelectric conversion element 10 is then sent to the scanner circuit 1 and converted into a digital signal.

Shading correction data is created prior to reading image data of a document. That is, light is irradiated from the light source 6 onto the surface of the document pressing roller 4 (shedding correction light reflection section), and the reflected light from the document suppressing roller 4 is reflected by the mirror 7 and the mirror 8, and is photoconducted by the condensing lens 9. The light is focused on the light receiving surface of the conversion element 10. The output of the photoelectric conversion element 10 is sent to the scanner circuit 1, where it is converted into a digital signal, and illuminance data (shading correction data) in the main scanning direction is obtained. Then, when reading image data from a document, the read image data is corrected based on the shading correction data so that the illuminance in the main scanning direction is uniform.

light source 6, document pressing roller 4, mirror 7 and mirror 8,
The condensing lens 9 and the photoelectric conversion element 1° are arranged so that the light emitted from the light source 6 and reflected by the document pressing roller 4 is focused on the light receiving surface of the photoelectric conversion element 1o.

At a position below the optical path S between the mirror 8 and the condensing lens 9, a transparent glass plate 12 for shifting the image formation position by the lens 8 is placed at a first position away from the optical path S (indicated by a solid line in FIG. 1). (shown in FIG. 1) and a second position (indicated by a chain line in FIG. 1) perpendicular to the optical path S.

The transparent glass plate 12 is fitted into a frame 13, and this frame 1
One end of 3 is fixed to a rotating shaft 15 rotatably supported by a pair of supporting members 14.

One end of the rotating shaft 15 is bent into a crank shape. A crank-shaped end portion of the rotating shaft 15 is connected to an operating portion of a solenoid 17 via a bell crank 16 .

Normally, the transparent glass plate 12 is below the optical path S,
It is located at a first position substantially parallel to the optical path S. When the solenoid 17 is driven and the operating portion is retracted, the bell crank 16 rotates in the direction of arrow A around the fulcrum, and the rotating shaft 15 rotates in the direction of arrow B accordingly.

As a result, the transparent glass plate 12 swings around the rotating shaft 15 and stands up, reaching a second position perpendicular to the optical path S.

FIG. 3 shows a shading correction data creation processing procedure performed prior to reading image data of a document.

First, when the power of the copying machine is turned on (step S1),
The solenoid 17 is driven and the transparent glass plate 12 is located at a second position perpendicular to the optical path S (step S2).

Next, a first shading correction data creation process is performed (step S3). That is, the light source 6 irradiates the document pressing roller 4 with light. The reflected light from the document pressing roller 4 is reflected by the mirrors 7 and 8, passes through the transparent glass plate 12, enters the condensing lens 9, and is received by the photoelectric conversion element 10 by the condensing lens 9. Then, the output of the photoelectric conversion element 10 is sent to the scanner circuit 11, where it is converted into a digital signal, and illuminance data (first shading correction data) in the main scanning direction is obtained. The first shading correction data is stored in the storage means.

Since the reflected light from the document suppressing roller 4 passes through the transparent glass plate 12, the image formation position by the condenser lens 9 is shifted from the light receiving surface of the photoelectric conversion element 1o.

Therefore, even if dirt is generated on the document suppression roller 4,
The influence of dirt on the document suppression roller 4 no longer appears on the first shading correction data. An example of the first shading correction data is shown in FIG.

Next, the drive of the solenoid] 7 is stopped, and the transparent glass plate 12 is returned to the first position out of the optical path S (step S4). Then, the document suppressing roller 4 is irradiated with light from the light source 6, thereby performing a second shading correction data creation process (step S5).

In this case, the reflected light from the original pressing roller 4 is reflected by the mirrors 7 and 8, and is incident on the condensing lens 9 without passing through the transparent glass plate 12, and is converted into photoelectric information by the condensing lens 9. The light is focused on the light receiving surface of the element 10. The output of the photoelectric conversion element 10 is sent to the scanner circuit 11, where it is converted into a digital signal, and illuminance data (second shading correction data) in the main scanning direction is obtained. The second shading correction data is stored in the storage means.

Since the reflected light from the document pressing roller 4 does not pass through the transparent glass plate 12, the light is focused on the light receiving surface of the photoelectric conversion element 10 and is imaged on the light receiving surface of the photoelectric conversion element 10. Therefore, if dirt is generated on the original suppression roller 4, the fifth
As shown by a in the figure, the second shading correction data is affected by the dirt on the original suppression roller 4.

After this, the first shading correction data and the second shading correction data are compared (step S6).
. If both correction data are the same (step S7), it is determined that there is no dirt on the original suppression roller 4, and the copying becomes possible (step S8). When reading a document, shading correction is performed based on the first or second shape ink correction data.

If both data are not the same (step S?), it is determined that the document pressing roller 4 is contaminated, and a notification means such as a display lamp or a display device informs that fact (step S9). . This allows the operator to know that the document pressing roller 4 is contaminated, so that the operator can perform processing such as cleaning the document pressing roller 4.

In the above embodiment, the transparent glass plate 12 for shifting the image formation position by the lens 8 is arranged so as to be inserted into the optical path S between the mirror 8 and the condensing lens 9. The transparent glass plate 12 may be inserted at any point along the optical path S until the light reflected by enters the charge conversion element 10. Further, a lens may be used instead of the transparent glass plate 12. Further, the present invention can also be applied to a copying machine using a fixed-original exposure method.

[Effects of the Invention] According to the present invention, it is possible to early and accurately detect that the shading correction reflection section is dirty, and therefore,
Image stains due to stains on the shading correction reflection section can be prevented.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic configuration diagram showing a document supply section and exposure section of a copying machine, FIG. 2 is an enlarged perspective view showing a transparent glass plate and its driving mechanism, and FIG. A flowchart showing a shading correction data creation processing procedure performed prior to reading image data of a document;
FIG. 4 is a diagram showing an example of first shading correction data, and FIG. 5 is a diagram showing an example of second shading correction data. 4... Original pressing roller, 6... Light source, 9... Condensing lens, 10... Photoelectric conversion element, 12... Transparent glass plate, 17... Solenoid. Figure 3 and above

Claims (1)

[Claims] (1) An imaging position arranged so that the light emitted from the light source and reflected by the shading correction light reflection section can freely enter and exit the optical path in the optical path until the light is focused on the photoelectric conversion means by the condensing lens. A light transmitting body for shifting, a driving device for moving the light transmitting body for shifting the imaging position into and out of the optical path, a driving device for moving the light transmitting body for shifting the imaging position into and out of the optical path, and causing the light transmitting body to enter the optical path and irradiate the light reflection unit for shading correction with light from the light source, and a first illuminance data creation means for storing first illuminance data in the main scanning direction in a storage means based on the output of the photoelectric conversion means on which the reflected light is incident; a second illuminance data creation means for emitting light from a light source and storing second illuminance data in the main scanning direction in the storage means based on the output of the photoelectric conversion means on which the reflected light enters; the first illuminance data and the second illuminance; A determining means for determining whether or not the light reflecting section for shading correction is dirty by comparing the data with An image forming apparatus comprising: a notification means for providing notification.