JPH0732446B2 - Image reader capable of moving and stationary reading - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a copying machine, facsimile machine, and other image reading devices.

[Conventional technology]

A specific example of such an apparatus is an image reading apparatus as shown in FIG.

The image processing of this is a platen (P) fixed type,
(I) a first mode in which the reading unit (optical system) is fixed and the upper surface of the unit is read while conveying the sheet material (original O) at a speed synchronized with the reading speed; and (ii) the sheet material is directly placed on the platen. And a second mode in which the reading section is scanned and reading is performed.

Here, in the first mode, the release sheet S is pressed against the platen P so as to be peeled off the sheet material O from the reading portion, but the leading edge of the sheet material rides over here and separates from the platen. Occasionally, a load is applied to the sheet material, which easily causes misalignment, damage, wrinkles, image blurring, and the like.

Therefore, a configuration has been devised in which the release sheet is passed across the upper portion of the reading unit to the opposite side (FIG. 5 (b)).

However, in such a configuration (FIG. 5 (b)), although the sheet is peeled off well, when reading through the transparent sheet, a density difference occurs between the first mode and the second mode. There is an inconvenience.

[Object of the Invention]

The present invention has been made in view of the drawbacks of the above-described conventional example, and an object of the present invention is to provide an image reading apparatus capable of eliminating the difference in reading density between the first mode and the second mode and performing good reading.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view of an embodiment of the present invention.

The section A is a sheet material conveying section, and the section B is an image processing section.

In the A section, 1 is a stacking tray for stacking documents. The tray 1 supports a document and is arranged so as to be lower on the document feeding side and inclined downward as it goes in the document feeding direction. As a result, the documents to be fed are stacked in the feeding direction. Further, at least a part of the tray 1 has a transparent window portion so that a discharged document discharged below the stacking tray 1 can be confirmed.

A pick-up roller 2 feeds a document to a downstream separating portion, and is fixed to the pick-up roller shaft 3. The shaft 3 is supported by a pick-up roller arm 4, and the arm 4 swings around a paper feed drive shaft 5. The rotation of the shaft 5 is transmitted to the shaft 3 by the timing belt 6 to rotate the pick-up roller 2. A feeding roller 7 fixed to the shaft 5 rotates in the arrow X direction (in the document feeding direction). Denoted at 8 is a separation drive shaft, and denoted at 9 is a separation roller fixed to the shaft 8 and rotates in the direction of arrow Y (original return direction).
Documents are separated one by one by the feeding roller 5 and the separating roller 9 and fed to the downstream conveying roller. 1,10a, 11,11
Reference numerals a, 12 and 12a are a pair of conveying rollers, which convey the document between the paper paths 13 and 14, respectively. The conveyance speed at this time matches the reading speed of the image reading apparatus, and good reading is performed.

Reference numeral 15 is a reflector, which is a white plate, and is attached to the vicinity of the upper part of the reading portion with a small distance from the platen gas 100. This distance is about 0.5 to 2 mm.

16 is a scraper (peeling) sheet which is a transparent member, and one end 16a thereof is fixed to the outer guide 13a of the path 13 and the other end 16b
Is free and is plugged into pass 14. The scraper sheet 16 is made of a transparent thin sheet elastic member, for example, a polyethylene terephthalate sheet (Mylar), and its thickness is preferably about 30 μ to 200 μ. Further, since the original passes through the upper part, it is more preferable if the conductive material such as indium is coated as a countermeasure against static electricity. The transparent member is positioned to face substantially the entire length of the processing section and contacts the processing surface to face it.

Reference numeral 17 is a pressure plate that can be opened and closed, and a pressure bonding sheet 17a is attached to the lower part of the pressure plate.

Reference numeral 20 is a leg, which enters the hole 120 of the B portion, and the upper portion is the hinge shaft 1
It is rotatably attached to the side plate 18 via 9 so that the B part can be erected and tilted.

S1 to S3 are sensors, S1 is a sensor for detecting the presence / absence of a document placed on the tray 1, and S2, S3 are for detecting the leading or trailing end of the document passing through the paths 13 and 14, respectively.

FIG. 2 is an explanatory diagram of the drive system. A motor 50 is fixed to the side plate 18a, and a motor pulley 51 is attached to the main shaft of the motor. Further, pulleys 52, 53, 54 are mounted on the shafts of the transport rollers 10, 11, 12, respectively. On the other hand, a paper feed drive pulley 55 is mounted on the paper feed drive shaft 5, a separation drive pulley 56 is mounted on the separation drive shaft 8 via a clutch 57, and a separation driven pulley 58 is fixed. There is. A belt 59 is stretched between the pulley 55 and the pulley 58.
A belt 60 (a double-sided belt also covers the pulley 56) is hung between the pulleys 51, 52, 53, 54 and 56, and the drive of the motor is transmitted.

Part B is an image processing part, 100 is a transparent platen glass, 101,1
02 and 103 are first to third mirrors, 104 is a lens, and 105 is
It is a CCD (charge coupled device or solid-state image sensor), and the image on the platen is formed on the CCD. Further, it has a hole portion 120 so that the leg 20 of the portion A can be inserted.

The operation of the above configuration will be described below.

First, the first mode (sheet material original mode) will be described.

(1) A large number of originals are set on the stacking tray 1 with the image side facing upward.

(2) Press the reading start key (not shown) on the operation section of the main body B section.

(3) When the start signal is input while the document presence sensor S1 is detecting the document, the motor 50 turns on and the transport rollers 10,1
Drive is transmitted to 1,12.

(4) Then (predetermined timer), the pick-up roller 2 descends, the clutch 57 turns on, and the separation roller 9, the feeding roller 7, and the pick-up roller 2 rotate.

(5) The uppermost one of the stacked documents is separated and enters the bus 13.

(6) When sensor S2 detects the leading edge of the document, the clutch
57 is turned off and the drive of the separation unit is stopped. The pick-up roller 2 also rises, and the document is pulled out by the rollers 10 and 10a. Take path 13.

(7) It is gripped by the rollers 11 and 11a and advances to the reading section.
When the leading edge of the document comes to the reading unit, the reading of the body B is started.
This timing comes a predetermined time after the sensor S2 is turned on.

(8) The tip goes inside the path 14 and is gripped by the roller pair 12, 12a. In the reading unit, reading proceeds in sequence.

(9) The document after the reading is completed is discharged onto the pressure plate 17. Feed the next original with sensor S3 OFF.

(10) Here, since the image surface faces downward, and the next original is stacked on it, the original page order is the same as when it was set, and the subsequent processing becomes easier.

(11) Sensor S1 indicates that the originals on Tray 1 are exhausted.
When the document is detected, the document being processed is completely discharged onto the pressure plate 17 and then stopped.

Next, the image reading process in the above operations (7) and (8) will be described in detail.

At this time, the document passes between the reflector 15 and the scraper sheet 16 with the image side facing down. Where the sflaper sheet
16 is supported by a cantilever, and the platen 100 faces diagonally downward.
Since it is supported so as to be pressed against the platen, it is in close contact with the platen 100 on the reading unit.

The reading here is performed via 161 sheets of the sflaper sheet. That is, normally, the light attenuation (passing light and reflected light) of 161 scraper sheets must be corrected in the same manner as in the book mode described later. Therefore, in this case, for example, in the sheet mode, the density can be corrected by making the main body lamp brighter than in the book mode. Further, the output from the CCD may be electrically corrected.

Next, the second mode (book mode) will be described.

(1) Rotate part A in the Z direction about the hinge shaft 19.

(2) Set the original on the platen 100.

(3) Press the start key (not shown).

(4) The first to third mirrors 101 to 103 of the B section start reading in the V direction.

(5) When reading is completed, it returns to the W direction.

(6) This operation is repeated a desired number of times.

That is, since the pressure plate 17 and the pressure bonding sheet 17a are included, it is possible to deal with a book (thick one) by rotating the hinge 19 around the center. Further, since the reading unit is based on the hinge unit, the distance between the hinge hole 120 and the reading unit is short, and the misalignment between the A and B portions is reduced.

Also, since the center of gravity is on the hinge side, the hinge portion can be simplified. Further, when the platen 100 is dropped from the standing state in the V direction, the platen 100 is buffered because the pressure plate 17 is located outward.

Further, in the book mode, unlike the sheet mode, since the scraper sheet is not used, the above-described correction is not performed. On the contrary, the correction may be performed when the scraper sheet does not exist on the basis of the sheet mode.

Now, the switching between the sheet mode and the book mode is performed by the sensor S1. That is, the sheet mode is automatically selected when the sensor S1 detects the document, and the book mode is automatically selected when there is no document.

Next, a specific method of correction will be described.

As shown in FIG. 6, when a start signal is input, it is determined whether or not the original is set on the tray. That is,
If S1 is ON, there is a document, and the following processing is performed in ADF MODE. If S1 is OFF, there is no manuscript and the following processing is BOOK
It is done in MODE.

In the book mode, the relationship between the set document density and the output density is as follows. FIG. 7A shows the document density and
It shows the relationship of the amount of light received by the CCD (straight line “Z”), that is, when the density is high, the amount of light is small.

FIG. 7B shows the relationship between the amount of light received by the CCD and the output voltage. That is, it indicates that the voltage is high when the light amount is large. And a predetermined Vs (slice level in Book mode)
When the voltage is higher than that, it is determined to be white, and when the voltage is low, it is determined to be black. For example, when the document density is Da, a → b → c → d and Vd> Vs, and it is determined that the document is white.

Scraper sheet 1 in ADF mode compared to BOOK mode
The sheet spectral amount decreases. That is, even if the original density is the same
The amount of light received by the CCD decreases. This is indicated by the straight line "Y" in FIG. 7 (a). Vs' is the slice level in ADF mode. If the same control is performed as in the book mode, then a → e → f → g when Da, Vg <Vs, and black is output, resulting in a difference between the book mode and the ADF mode. The following method is used to correct this.

(I) Increase the light intensity of the lamp.

Raise the light intensity of the lamp to prevent a decrease in light intensity for one scraper sheet. That is, one method is to move the straight line "Y" in the direction of the arrow and increase the lighting voltage of the lamp so as to coincide with "Z".

(Ii) Change the Vs setting.

Lower the slice level Vs of CCD voltage. That is, the second method is to move the Vs line in the downward direction to Vs'.

As mentioned above, when in ADF MODE, the density is corrected using the above method 1 or 2 (combination of 1 and 2 is also possible), and BOOK mode and A
It is possible to eliminate the difference in farming degree between DF modes.

On the contrary, the above correction may be applied to the BOOK mode based on the ADF mode as a standard.

As described above, according to the embodiment of the present invention, the first mode for reading through the excellent member and the second mode for not reading through the member.
There is no difference in density from the mode of 1, and good reading is performed.

Further, since the excellent member guides the sheet material, the sheet material can be satisfactorily conveyed.

〔The invention's effect〕

As described above, according to the present invention, the first mode for reading through the transparent member and the second mode for reading without passing through the transparent member.
There is no difference in density between the two modes, and good reading is performed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a sheet material conveying unit mounted on an image processing unit, FIG. 2 is a drive system explanatory diagram, FIG. 3 is a paper path explanatory diagram,
FIG. 4 is an explanatory view of the reading unit, FIG. 5 is an explanatory view of a conventional example, FIG. 6 is a flow chart of the present invention, and FIG. 7 is an original density-CC.
FIG. 6 is a diagram showing a relationship between D received light amount, CCD output voltage-CCD received light amount. 15 …… Reflector, 16 …… Scraper sheet (transparent member), A …… Sheet material conveying section, B …… Image processing section.

Claims (1)

[Claims] 1. A sheet document moving / reading mode comprising an automatic sheet document feeding device for feeding and moving a sheet document to a predetermined image reading position on a platen by the device to perform image reading by an optical system. In an image reading device capable of selecting a still image reading mode in which a sheet original is statically placed on a platen and an optical system is moved to perform image reading, a sheet original is interposed between the platen and the sheet original at the image reading position. A transparent member for guiding the moving sheet original, and means for performing density correction between the sheet original moving reading mode for reading through the transparent member and the original stationary reading mode for reading without passing through the transparent member. An image reading device capable of moving and stationary reading.