JP3151028B2 - Image forming device - Google Patents

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 and 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.
Judging from the size of the original tray, using a yellow original cover, irradiating light from below the contact glass with the original sandwiched between the original cover and the contact glass, The size of the document is determined based on the difference in the reflected light (Japanese Patent Laid-Open No. 59-1000046), or a plurality of light-emitting elements and light-receiving elements are provided, and the size of the document is detected from the light blocked by the document. (Japanese Patent Laid-Open No. 61-11305)
No. 4). Further, a plurality of sets of light emitting elements and light receiving elements are provided at the stop position of the document to detect whether or not the document is set at a normal position (Japanese Patent Laid-Open No. 2-284573).

[0003]

As described above, when the size of an original is determined by the digital copying machine based on the size of the width set of the original tray, copying is performed. Even though they are all unified into large ones. Therefore, it is necessary to change the setting of the width of the document tray for each document, and the operation is troublesome.

When the size of a document is automatically recognized by using a document holding cover, the size of a yellow document 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, the circuit becomes complicated because many elements as a scanner used for reading the document must be used. Would.

Further, when a document is set at a position other than the designated position, the document is currently transmitted or copied irrespective of its state. For this reason, the original was transmitted or copied with a part of the original missing, and this was sometimes not noticed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantages, and an object of the present invention is to provide an image forming apparatus capable of accurately recognizing the size of a document with a simple structure and performing recording without missing. It is the purpose.

[0008]

An image forming apparatus according to the present invention is provided under a contact glass on which a document to be read is placed.
Section so that it can be moved freely
Irradiates light, receives the reflected light, and places it on the contact glass.
Reading means for reading an image of an original, and a contact glass
Move freely along the contact glass on top of the upper document
Having a light emitting plate provided, and reading a document with a reading device
Sometimes, the light receiving optical path range of the light emitted from the reader to the light emitting plate
To receive the light emitted from the reader by the leading edge of the document.
Light from the reader when sent to the optical path range for a certain time
Illuminate, the luminous plate emits light from the irradiated part,
The reader receives the light from the light-emitting plate and detects the size of the original.
It is characterized by putting out .

A light emitting plate is provided adjacent to the shading plate, and the shading plate and the light emitting plate are slid by sliding means.
To the light receiving optical path range of the light emitted from the reading device.
It is desirable to move.

It is desirable that the light emitting plate is a fluorescent plate. Further, the light emitting plate may have a light source.

In another image forming apparatus according to the present invention,
Moveable to the bottom of the contact glass on which the original to be taken is placed
Irradiates the original on the contact glass with light,
Receiving the reflected light, the image of the original on the contact glass
And reading means for reading the
Light source attached to the cover that holds
The original is placed on the contact glass and
When the bar is closed, the light emitting plate emits light and the reading device
Move the reading device in the reading direction without irradiating light.
Receives light from the light emitting plate that is not blocked by the original
The reading range of the document is detected.

[0012]

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

Further, when the light emitting plate is provided adjacent to the shading plate, and the shading plate and the light emitting plate are slid to be set alternately at the same position, it is difficult to perform shading correction. The shading correction and the determination of the position and size of the document can be performed without taking any necessary steps.

[0014]

FIG. 1 is a block diagram showing an embodiment of the present invention. As shown in the figure, a 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 drive unit 8, a light emitting plate 9 And a paper selection unit 10.
The scanner 4 has a contact glass 11 as shown in FIG.
A lamp 41 for irradiating the upper document 12 with light and its reflected light
Mirror 42, lens system 43 and CCD 44 for changing the direction of
And The light emitting plate 9 is made of a fluorescent plate that emits fluorescent light,
It is integrally mounted on the same plane as the shading plate 7,
A plurality of rollers 1 rotated by a shading drive unit 8
3 makes it possible to move. Paper selection unit 10
Selects the recording paper according to the document to be recorded.

With the copying machine constructed as described above, the original 12
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 drive unit 8 to move the shading plate 7 and the light emitting plate 9 so that the light emitting plate 9 enters the light receiving optical path range as shown in FIG. . Thereafter, the ADF 6 sends the document 12 so that the leading end of the document 12 enters 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 predetermined time, for example, one second. As a result, the light emitting plate 9 on the original 12
The light is radiated only from a portion of the document 12 which is not blocked. This light passes through the mirror 42 and the lens system 43
D44. When 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 at which a portion corresponding to the position and size of the document 12 has a low level. The output signal is amplified and binarized by a constant level threshold value B, and a portion outputting a low level output is stored in the memory 2 as a read valid bit.

Thereafter, the shading driving section 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
The document 12 is returned once outside the reading range of the scanner 4 by F6. Then, the paper selecting unit 10 selects a recording paper corresponding to the read valid bit previously stored in the memory 2, reads the contents of the original 12 by the scanner 4 and copies it onto the selected recording paper while sending the original 12 by the ADF 6.

When the document 12 is recorded on the recording paper in this manner, the position and size of the document are detected by the light from the light emitting plate 9 by the scanner 4 for reading the document, and the recording corresponding to the position and size is performed. Since the paper is selected and recorded, even if the position of the document is shifted, it is possible to reliably record without losing the contents. Also, when performing shading correction, the shading plate 7 and the light emitting plate 9 are integrally mounted so that they can be moved, so that the light emitting plate 9 can be mounted without taking up space.

[0018] The above embodiment uses the EL plate has been described using an electroluminescent the case of using the fluorescent plate which emits fluorescence as a light emitting plate 9, directly onset light from the light emitting plate 9
You may do it.

FIG. 4 shows an example in which the cover 14 for holding the original 12 is EL.
An example of a copier in which a light emitting plate 9a made of a plate is attached and a scanner 4 moves is shown. In this case, the original 12 is placed on the contact glass 11 and the cover 14 is closed. When the original 12 is placed on the contact glass 11,
For example, as shown in the explanatory diagram of FIG. 5, it is assumed that the document 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 emit light. The light from the light emitting plate 9a is read by the CCD 44 while the scanner 4 is moved in the X direction from the position of X = 0 without turning on the lamp 41 of the scanner 4.
When the scanner 4 reaches the position X1, 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 is
Is detected. 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 light reaches the end 12b of the original 12, the state of change of light incident on the CCD 44 changes, and the end 12b of the document 12 is detected. The coordinates X2 and Y2 of this position are also stored in the memory 2. In this way, the scanner 4 is sequentially moved to move the
c and 12d are detected, and the coordinates X3 and Y3 of the end 12c and the coordinates X4 and Y4 of the end 12d are also stored in the memory 2.

Then, the end portion 12d of the document 12 is detected and emitted.
When all the light from the light plate 9a is incident on the CCD 44, the light from the light emitting plate 9a is turned off. Then, memory 2
The paper selection unit 10 selects a recording paper having a length closest to the length from X1 to X4 and the width from Y2 to Y3 from the coordinates of each end of the original 12 stored in the
The document 12 is read while the scanner 1 is turned on and the scanner 44 is moved from the position X4 to the position X1, and is copied onto a selected recording sheet.

In this way, even when the document 12 is not set at a predetermined position, the contents of the document 12 can be copied accurately without losing the contents.

[0023]

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

Also, the size of the recording paper is selected according to the detected size of the original, and the original is recorded.
Regardless of the setting state of the original, a good record without any missing can always be obtained.

Further, when performing the shading correction, the light emitting plate is integrated adjacent to the shading plate so that the shading correction and the determination of the position and size of the original can be performed without taking up space. It can be carried out.

Further , the light emitting plate may be constituted by a fluorescent plate,
By providing a light source on the plate, the size of the original can be reliably detected.
Can be issued.

[Brief description of the 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 embodiment.

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

FIG. 4 is a layout diagram of another embodiment.

FIG. 5 is an operation explanatory view of the embodiment shown in FIG. 4;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 CPU 2 Memory 4 Scanner 7 Shading plate 9, 9a light emitting plate 10 Paper selection unit 44 CCD

Claims (3)

(57) [Claims] 1. A contact glass on which a document to be read is placed.
Movably provided at the bottom of the contact glass
Irradiates the original with light, receives the reflected light, and contacts
Reading means for reading an image of an original on a lath, and a contact
Move along the contact glass to the top of the original on the glass
A light emitting plate provided freely, and when reading a document with the reading device, the light emitting plate is moved from the reading device.
Move to the light receiving optical path range of the irradiated light, and read the leading edge of the original.
When the light emitted from the sampling device is sent to the light path
Light is emitted from the reader for a certain period of time, and the light-emitting plate
The reader emits light from the light-emitting plate,
An image forming apparatus for detecting the size of a document by receiving light . 2. A light emitting plate is provided adjacent to a shading plate, and the shading plate and the light emitting plate are irradiated from a reader.
The image forming apparatus according to claim 1, further comprising a slide unit that alternately moves to a light receiving optical path range of the light . 3. A contact glass for placing a document to be read.
Movably provided at the bottom of the contact glass
Irradiates the original with light, receives the reflected light, and contacts
Reading means for reading an image of an original on a lath, and a contact
Attached to the cover that holds the original placed on the glass
And a light emitting plate with a light source, the original is placed on the contact glass and the cover is closed.
To emit light from the light-emitting plate and not emit light from the reader
In this state, the reading device is moved in the reading direction and blocked by the original.
Receives light from the light emitting plate that is not
An image forming apparatus comprising: