JPH05165117A - Image forming device - Google Patents

Abstract

PURPOSE:To detect the position and the size of an original without requiring a photodetector or the like other than a read means and to simplify parts or circuit configuration by irradiating the original with light from the above thereof and detecting the position and the size of the original by the light shielded by the whole of the original. CONSTITUTION:A scanner is provided with a lamp 41 from which the original 12 on a contact glass 11 is irradiated with the light, a mirror 42 changing the direction of the reflected light thereof, a lens system 43 and a CCD 44. A light emitting plate 9 is constituted of a fluorescent plate, integrally fitted to the same plane surface as a shading plate 7, and moved by plural rollers 13 which are rotated. Besides, a recording paper is selected by a paper selection part according to the original to be recorded. Since the original 12 is recorded on the recording paper by detecting the position and the size of the original by the scanner which reads the original with the light from the plate 9 and selecting the recording paper according to the position and the size, it is surely recorded without omitting the content thereof even when the position of the original is deviated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a facsimile machine or a digital copying machine.

[0002]

2. Description of the Related Art For example, an automatic document feeder (ADF) is used to recognize the size of a document to be copied by a digital copying machine.
Judgment based on the size of the original tray, or using the yellow original cover, and with the original sandwiched between the original cover and the contact glass, irradiate light from the bottom of the contact glass, The size of the original is judged based on the difference in the reflected light (Japanese Patent Laid-Open No. 59-100464), and the size of the original is detected from the light blocked by the original by providing a set of a plurality of light emitting elements and light receiving elements. (JP-A-61-113054). Further, a set of a plurality of light emitting elements and light receiving elements is provided at the stop position of the original to detect whether the original is set at a normal position (Japanese Patent Laid-Open No. 2-284573).

[0003]

As described above, when the size of a document is judged by the size of the width set of the document tray in the digital copying machine and copying is performed, when there are documents of different sizes. However, they are all unified into a large one. Therefore, it is necessary to change the setting of the width of the document tray for each document, and the operation is troublesome.

Further, when the size of the original is automatically recognized by using the original pressing cover, the size of the yellow original cannot be recognized.

Further, in the case of recognizing the size of a document by using a combination of a plurality of light emitting elements and light receiving elements, many elements as a scanner used for reading a document must be used, which complicates the circuit. Will end up.

Further, when the original is set at a position other than the designated position, it is currently transmitted or copied as it is regardless of the state. For this reason, some of the manuscripts were transmitted or copied with some parts missing, and the fact was not noticed in some cases.

The present invention has been made to solve the above drawbacks, and provides an image forming apparatus capable of accurately recognizing the position and size of an original with a simple structure and performing recording without omission. The purpose is that.

[0008]

SUMMARY OF THE INVENTION An image forming apparatus according to the present invention includes a light emitting plate that emits light from the upper surface of a document and a reading device that receives the light emitted from the light emitting plate to detect the position and size of the document. And a paper selection unit for selecting the size of the recording paper according to the position and size of the document detected by the reading unit.

Further, it is preferable that the light emitting plate is provided adjacent to the shading plate, and the shading plate and the light emitting plate are alternately set at the same position by the sliding means.

[0010]

According to the present invention, light is emitted from the light emitting plate provided on the upper surface of the original, and the position and size of the original are detected by the light intercepted by the reading means. The size of the recording paper is selected according to the detected position and size of the document, and the read document is recorded.

Further, if the light emitting plate is provided adjacent to the shading plate and the shading plate and the light emitting plate are slid so as to be alternately set at the same position, the position when performing the shading correction is improved. The shading correction and the position and size of the original can be determined without taking the above steps.

[0012]

1 is a block diagram showing an embodiment of the present invention. As shown in the figure, the copying machine includes a CPU 1 for managing the entire apparatus, a memory 2 for storing various information, a signal processing unit 3, a scanner 4, a recording unit 5, an ADF 6, a shading plate 7, and a shading drive unit 8. Besides, it has a light emitting plate 9 and a paper selection unit 10. As shown in FIG. 2, the scanner 4 has a lamp 41 that irradiates the original 12 on the contact glass 11 with light, a mirror 42 that changes the direction of the reflected light, a lens system 43, and a CCD 44. The light emitting plate 9 is composed of a fluorescent plate which emits fluorescent light, is integrally attached to the same plane as the shading plate 7, and can be moved by a plurality of rollers 13 rotated by a shading drive unit 8. .. The sheet selection unit 10 selects a recording sheet according to the document to be recorded.

The original 12 is produced by the copying machine constructed as described above.
When reading and recording, first the shading plate 7
Is placed in the light receiving optical path range of the light from the CCD 44, and the signal processing unit 3 performs shading correction of the light receiving system. Next, the roller 13 is rotated by the shading driving unit 8 to move the shedding plate 7 and the light emitting plate 9 so that the light emitting plate 9 is within the light receiving optical path range as shown in FIG. .. After that, the original 12 is sent by the ADF 6 so that the front end of the original 12 is in the light receiving optical path range of the light from the CCD 44. In this state, the lamp 41 of the scanner 4 is turned on, and is turned off after a fixed time, for example, 1 second. As a result, the light emitting plate 9 on the original 12 is
Light is radiated only from the portion of the original 12 that is not blocked. This light passes through the mirror 42 and the lens system 43 to CC
It is incident on D44. When the light from the light emitting plate 9 is incident on the CCD 44, as shown in FIG. 3A, the CCD 44 sends out an output signal that makes a portion corresponding to the position and size of the original 12 low. This output signal is amplified and binarized by a constant level threshold value B, and the portion outputting the low level output is stored in the memory 2 as a read valid bit.

Thereafter, the shading drive unit 8 moves the shading plate 7 and the light emitting plate 9 again to return the shading plate 7 to the light receiving optical path range of the light from the CCD 44, and AD
The original 12 is once returned to the outside of the reading range of the scanner 4 by F6. Then, the paper selection unit 10 selects a recording paper corresponding to the read valid bit previously stored in the memory 2, and while the original 12 is fed by the ADF 6, the contents of the original 12 are read by the scanner 4 and copied onto the selected recording paper.

When the original 12 is recorded on the recording paper in this way, the scanner 4 for reading the original detects the position and size of the original by the light from the light emitting plate 9, and performs recording according to the position and size. Since the paper is selected and recorded, even if the position of the document is deviated, it is possible to reliably perform recording without loss of contents. Further, when the shading correction is performed, the shading plate 7 and the light emitting plate 9 are integrally attached so as to be movable, so that the light emitting plate 9 can be attached without taking up a space.

In the above embodiment, the case where a fluorescent plate which emits fluorescent light is used as the light emitting plate 9 has been described, but an EL plate utilizing electroluminescence is used and light is directly emitted from the light emitting plate 9. good.

FIG. 4 shows that the cover 14 for holding the original 12 has an EL.
An example in the case of a copying machine in which the light emitting plate 9a made of a plate is attached and the scanner 4 moves. In this case, the original 12 is placed on the contact glass 11 and the cover 14 is closed. When this original 12 is placed on the contact glass 11,
For example, as shown in the explanatory view of FIG. 5, it is assumed that the original 12 is inclined with respect to the light emitting plate 9a.

In this state, first, a voltage is applied to the light emitting plate 9a to cause it to emit light. Then, the light from the light emitting plate 9a is read by the CCD 44 while moving the scanner 4 from the position of X = 0 in the X direction without turning on the lamp 41 of the scanner 4.
When the scanner 4 reaches the X1 position, the light from the light emitting plate 9a is blocked by the end 12a of the original 12 and the end 12a of the original 12a is blocked.
To detect. The coordinates X1 and Y1 of this position are stored in the memory 2. When the scanner 4 further moves, the light incident on the CCD 44 changes according to the contour of the document 12,
When the edge 12b of the original 12 is reached, the state of change of the light incident on the CCD 44 changes, and the edge 12b of the original 12 is detected. The coordinates X2 and Y2 of this position are also stored in the memory 2. In this manner, the scanner 4 is sequentially moved to move the end portion 12 of the original 12
c, 12d are detected, and the coordinates X3, Y3 of the end 12c and the coordinates X4, Y4 of the end 12d are also stored in the memory 2.

When the edge 12d of the original 12 is detected and all the light from the light emitting plate 9a enters the CCD 44, the light from the light emitting plate 9a is turned off. Then memory 2
The recording sheet of the dimension closest to the lengths X1 to X4 and the widths Y2 to Y3 from the coordinates of the respective ends of the original 12 stored in the sheet selection section 10 is selected by the sheet selection section 10, and the lamp 4 of the scanner 4 is selected.
The original 12 is read while 1 is turned on and the scanner 44 is moved from the position X4 to the position X1, and is copied onto the selected recording paper.

In this way, even if the original 12 is not set at a predetermined position, the content of the original 12 can be accurately copied without omission.

[0021]

As described above, according to the present invention, the light is emitted from the upper surface of the document and the position and the size of the document are detected by the light blocked by the reading device as a whole. The position and size of the document can be detected without the need for a light receiving element other than the above, and the parts and circuit configuration can be simplified.

Further, since the size of the recording paper is selected and the original is recorded according to the detected position and size of the original, good recording is always performed without missing regardless of the setting condition of the original. Can be obtained.

Further, when performing the shading correction, the light emitting plate is integrally formed adjacent to the shading plate so that the shading correction and the position and size of the original can be determined without taking a space. It can be carried out.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a layout view of a light emitting plate of the above embodiment.

FIG. 3 is an explanatory diagram showing the output of the CCD in the above embodiment.

FIG. 4 is a layout view of another embodiment.

5 is an operation explanatory diagram of the embodiment shown in FIG.

[Explanation of symbols]

 1 CPU 2 Memory 4 Scanner 7 Shading Plate 9, 9a Light Emitting Plate 10 Paper Selection Section 44 CCD

Claims (2)

[Claims] 1. A light emitting plate which emits light from the upper surface of a document,
A reading unit that receives the light emitted from the light emitting plate to detect the position and size of the document, and a sheet selection unit that selects the size of the recording paper according to the position and size of the document detected by the reading unit. An image forming apparatus characterized by being provided. 2. The image forming apparatus according to claim 1, further comprising a light emitting plate adjacent to the shading plate, and a slide means for alternately setting the shading plate and the light emitting plate at the same position.