JP2543950B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a copying machine.

[Prior Art] Conventionally, when a person who uses an image forming apparatus places an original on an original placing plate of the image forming apparatus, it may be misaligned. Alternatively, when closing the document pressing cover, the document may be displaced due to wind pressure.

[Problems to be Solved by the Invention] However, in the conventional image forming apparatus, whether the original is placed at an accurate position on the original placing plate or the original is misaligned, the image is formed without any concern. ing.

Therefore, a part of the image of the image-formed copy may be missing.

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the conventional image forming apparatus described above, and an object of the present invention is to provide an image forming apparatus that can form an image normally even when a document is placed with a slight deviation.

[Means for Solving the Problem] The present invention according to claim 1 collects a document placing plate on which a document is placed, a document scale for aligning the document, and reflected light of light emitted from a light source on the document. In an image forming apparatus including an image forming mechanism having a lens body that emits light and projects the light onto a photoreceptor, and a paper feeding unit that supplies paper, a document that is provided in the vicinity of the document scale and detects displacement of document placement The misregistration detection sensor, the correction control unit that controls the lens body or the paper feeding unit in the image forming mechanism to correct the image forming operation according to the output of the document misregistration detection sensor, and the document misregistration detection sensor A plurality of document detection sensors provided as separate members for detecting the document size, and when the document deviation detection sensor detects document deviation, the document detection sensor detects the misaligned document. The image forming apparatus corrects the known detection size correctly by the output of the document misregistration detection sensor and determines the size of the sheet to be supplied based on the correction.

[Operation] In the present invention according to claim 1, the document misregistration detection sensor is
The deviation of the placement of the original placed on the original placing plate is detected, and the correction control unit controls the lens body or the paper feeding unit based on the detection signal to form an image accurately, and further The detection size detected by the document detection sensor with respect to the misaligned document is correctly corrected by the output of the document misregistration detection sensor, and the size of the paper to be supplied is determined based on the corrected size.

[Examples] The present invention will be described below with reference to the drawings illustrating the examples.

FIG. 1 is a plan view centering on a document placing plate of an embodiment of an image forming apparatus according to the present invention, and FIG. 2 is a document misregistration detecting sensor and a document size detecting device according to the embodiment. FIG. 3 is a vertical sectional view of the same embodiment, with a perspective view centering on a document size detection sensor and the like.

In FIG. 1, reference numeral 2 is an original placing plate 1 on which an original is placed.
It shows an area in which originals of sizes A5, B5, A4, B4, A3, etc. are placed. A document scale 3 for aligning documents is provided on one side of the document plate 1.

A sensor holding frame 4 for holding the document size detecting sensors 51, 52, 53, 54, 55 at predetermined intervals as shown in FIG. 2 is located below the document placing plate 1. . The predetermined interval is a predetermined interval as shown in FIG. 1, which is capable of detecting various document sizes as conventionally known.

Further, as shown in the drawing, a document shift detection sensor 6 is attached to a sensor holding frame portion 4a at one end of the sensor holding frame 4, that is, near the document scale 3. The reason for this is that if the document is placed with a large deviation, it is considered that the user did not intentionally shift the document, but the user intentionally shifted the document and placed it. Because it is not considered. This is also for facilitating the later-described correction. It should be noted that the distance from the document mounting side edge portion 3a of the document scale 3 is x, and the distance between the upper edge (on the drawing) edge m of the A5 size document mounting area and the document size detection sensor 54 is y. Then, the distance x is y ≦ x
It is desirable to satisfy the relationship. That is, for example, when the deviation of the A5 size document 19 is detected, the document size detection sensor 54 is always turned on. In such a case, the document size determination means (CPU) uses a conventionally known logical determination. This is to allow the document size (A5) that is one step smaller than the determined document size (B5 because the document size detection sensor 54 is on) to be output as a result after the determination. When another document size is detected, it is determined that the document size is one step lower. In this way, the position of the document deviation detection sensor 6 and the document size detection sensors 51 to 55 are
By setting the positions of (1) to (3) in a predetermined relationship, the size of the document can be properly detected. If the original size detection sensors 51 to 55 are different in distance from the upper edge of each original area such as A5, the maximum distance is set. Also,
The relation between y and x is substantially and slightly changed depending on the effective diameter of the sensor.

The structure of the document misregistration detection sensor 6 is composed of a combination of a light emitting element and a light receiving element similar to the known document size detection sensor. The position of the document misalignment detection sensor 6 may be provided outside the document placing plate 1, that is, provided on the document scale 3 below the hole.

As shown in FIGS. 2 and 3, the sensor holding frame 4 is held by a first optical moving body 10 holding a light source 7, a reflection mirror 8 and the like. Therefore, the first optical moving body 10
Can be moved according to the movement of the. Reference numerals 11 and 11 are guide members for supporting the movement, and 12 is a wire for causing the movement. In FIG. 3, the lens body 13 collects the document reflected light A reflected through the first optical moving body 10 and the second optical moving body 9, and irradiates the photosensitive drum 14 as a light receiving body with a single lens or the like. Lens means.

Around the photosensitive drum 14, a developing device 15 and a paper feeding means 1
6, a transfer separator 17, a cleaning device 18, etc. are arranged. Further, in the figure, 19 is an original placed on the original placing plate 1, and 20 is an original pressing cover for pressing the original 19.

The document deviation detection sensor 6 held by the sensor holding frame 4 is connected to the correction control means 21. The correction control means 21 determines whether there is a deviation in the document placement according to the output of the document deviation detection sensor 6 and is a part of the image forming mechanism 100, for example, the lens body 13 or the paper feeding means 16 or the like. For correcting the image forming operation. In the figure, 13a is a drive means for moving the lens body 13. Reference numeral 16a is a paper feed mechanism drive means for moving the paper feed means 16. The correction control means 21 is usually realized by using a microcomputer.

Next, the operation of the above embodiment of the present invention will be described with reference to FIG. 5 showing the operation.

A person who uses the image forming apparatus, as shown in FIG.
A document 19 is placed on the document plate 1. Then, the document pressing cover 20 is closed. Then, the known document pressing cover closing operation detector 23 detects the closing operation via the detection rod 22 mounted on the main body of the apparatus near the mounting portion of the document pressing cover 20 (step S1). Accordingly, the document size detection sensors 51 to 55 operate, and the document displacement detection sensor 6 operates (step S2). That is, the document misalignment detection sensor 6 emits light toward the document 19. If the original 19 is displaced, the light is not reflected, and if the original 19 is not displaced, the light is reflected.
Therefore, the document misalignment detection sensor 6 can detect the misalignment of the document 19 by receiving the reflected light. Also, the document size detection sensors 51 to 55
Irradiate toward 19. Depending on the size of the manuscript 19,
The sensors turn on or off.

Therefore, the document size detection sensors 51 to 55 detect the document size as described above (step S3). Further, the document misalignment detection sensor 6 detects whether or not the document 19 is misaligned (step S4).

The correction control unit 21 controls a part of the image forming mechanism 100 based on the output of the document shift detection sensor 6 (step S5). For example, when the document 19 is displaced (step S4), the correction control means 21 shifts the lens body 13 obliquely to the photosensitive drum 14 side through the lens body drive means 13a as shown in FIG. Change the magnification (L1 / L2) and slightly reduce the correction so that the image is not missing (step S
Five). Here, L1 is the size of the original document 19, and L2 is the distance from the end of the original document scale 3 to the far end of the original document 19.

As another method, the correction control means 21 performs lateral shift correction of the lens body 13 as shown in FIG. 7 through the lens body drive means 13a so that the image is not lost (step S5). ).

Furthermore, as another method, the correction control means 21 is
As shown in FIG. 8, the paper feeding mechanism driving means 16a is driven to control the paper feeding means 16, and for example, the paper feeding cassette or the like is displaced so that the paper 24 is normally moved by the displacement x of the original document 19. It can be sent in a state where it is displaced from the correct position. In this way, the image can be prevented from being missing (step S5).

Furthermore, as another method, the correction control means 21 is
The correction can also be performed by twisting the reflection mirror 50 that irradiates the photoconductor drum 14 with the image light that has passed through the lens body 13.

If the original 19 is not misaligned (step S4),
No correction is made by the correction control means 21.

Finally, as shown in FIG. 3, the first optical moving body 10 and the second optical moving body 9 are moved to form an image (step S6).

 The present invention can also be implemented in the variable power mode.

In addition, the document size detection sensor does not make the document size judgment as one paragraph, and always uses a known logic to
The size may be determined.

[Advantages of the Invention] As is clear from the above description,
The image forming apparatus according to the second aspect of the present invention includes the document misalignment detection sensor that detects the misalignment of the document placement, and the correction control unit that controls a part of the image forming mechanism based on the detected misalignment. Even if the placement of the document is shifted, it is possible to form the image without missing the image.

According to the third aspect of the present invention, an image can be formed by further appropriately determining the document size.

[Brief description of drawings]

FIG. 1 is a plan view centering on a document placing plate in an embodiment of the image forming apparatus according to the present invention, and FIG. 2 is a perspective view centering on the first optical moving body in the embodiment, 3 is a vertical cross-sectional view of the same embodiment, FIG. 4 is a vertical cross-sectional view centering on the original cover of the same embodiment, FIG. 5 is a flow chart for explaining the operation of the same embodiment, and FIG. FIG. 7 is a diagram showing the relationship between the document placing plate and the paper for explaining the operation of the embodiment,
FIG. 7 is another relationship diagram of the document placing plate and the paper for explaining the operation of the embodiment, and FIG. 8 is a document placing plate and the paper for explaining the operation of the embodiment. It is another relationship diagram of. 1 ... Original plate, 3 ... Original scale 4 ... Sensor holding frame, 51-55 ... Original size detection sensor 6 ... Original deviation detection sensor 10 ... First optical moving body, 13 ... Lens body 14 ... Photoreceptor, 16 ... Paper feeding means 21 ... Correction control means, 100 ... Image forming mechanism

Continuation of the front page (56) Reference JP-A-60-46576 (JP, A) JP-A-60-168165 (JP, A) JP-A-63-96649 (JP, A) JP-A-1-261666 (JP , A) JP 56-88153 (JP, A) JP 61-6673 (JP, A) JP 59-2032 (JP, A) JP 60-70436 (JP, A) JP 61-289338 (JP, A) JP-A-62-170948 (JP, A) Actually opened 62-193251 (JP, U) Actually opened 59-73745 (JP, U)

Claims (1)

(57) [Claims] 1. A document placing plate for placing a document, a document scale for aligning the document, a lens body for collecting reflected light of the document emitted from a light source and projecting it onto a light receiving body, and a paper sheet. In an image forming apparatus having an image forming mechanism having a sheet feeding unit for feeding, a document deviation detection sensor provided near the document scale for detecting a deviation of document placement, and an output of the document deviation detection sensor Among the image forming mechanism, a plurality of correction control means for controlling the lens body or the paper feeding means to correct the image forming operation and a plurality of document size detecting sensors provided as separate members are provided for detecting the document size. When the document deviation detection sensor detects a document deviation,
An image characterized in that a detection size detected by the document detection sensor with respect to the misaligned document is correctly corrected by the output of the document misregistration detection sensor, and the size of the sheet to be supplied is determined based on the correction. Forming equipment.