JPS6346867A - Image reader - Google Patents

Abstract

PURPOSE:To position a thick original as well as a sheet original with a high precision to obtain a vivid read image by driving wide and narrow platen area surfaces with a thick original placing reference rule member as the boundary. CONSTITUTION:A wide platen area surface I on which the thick original can be placed and a narrow platen area surface II are provided with a thick original placing reference rule member 27 of an image reader A as the boundary. When a sheet original automatic supply device B is brought down on a platen 2 of the reader A, the turned-down picture surface of the sheet original is illuminated with a lamp 4 in the course where it passes a slit aperture part while closely brought into contact with the area surface II, and the image of this reflected light is formed on a CCD array to obtain a corresponding time series picture element signal. In case of the thick original, the device B is opened and raised from the platen 2 to place the original, and the device B is pressed in by a press-fitting plate part 16 to optically scan the picture surface, thus photoelectrically reading the image.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention [Field of Industrial Application] The present invention relates to an image reading device such as a facsimile machine-image reader copying machine.

More specifically, the present invention relates to an image reading apparatus that includes a platen on which a thick original can be placed and an automatic sheet original feeding device that feeds the sheet original to the platen surface.

[Conventional technology]

sheet document automatic feeder
Various systems and forms of image reading apparatuses including feeders (hereinafter abbreviated as ADF devices) and the ADF devices are known. Figure 7 shows a typical example.

A is an image reading device, and the one in this example is of a photoelectric reading type with a built-in CCD reduction optical system. The image reading device B may be an image reading device or an image forming device of an analog imaging system using a contact sensor, a Calson process, etc., and B is an ADF device provided in the image reading device.

In the image reading device A, 1 is the main body of the device, 2
3 is a transparent platen plate such as a glass plate attached to a large window hole formed on the top plate of the machine housing; 3 is a CCD reduction optical system as an image reading means built into the machine housing; and 3 is a document illumination system. Lamp 4, movable tube 1-third mirror 5-7. Imaging lens 8, CCD array (line charge c
(upled device) Consists of 9 mag.

The lamp 4 and the movable first mirror 5 are always on standby at the position indicated by the solid line below the bottom surface on the left side of the platen 2 as their home position, and based on the image reading start signal, both 4 and 5 move together to the bottom surface of the platen 2. It moves forward toward the right side of the platen at a predetermined speed ■, and reaches a predetermined forward movement end point (indicated by a two-dot chain line
When it reaches point 5'), it turns into a backward motion and returns to its initial home position.

The movable second mirror 6 and the third movable mirror 7 are also always on standby with the position indicated by the solid line as their home position.
・In conjunction with the forward movement of the first mirror 5, both move forward 6' and 7' in the same direction as the ramp 4 and mirror 5 at a speed of V/2.
The lamp 4 and the mirror 5 move back in conjunction with each other to return to the initial home position.

In the ADF device B, reference numeral 11 denotes a sheet document set tray as a sheet document setting position, which is disposed on the right side of the image reading device A so as to protrude outward integrally with the main body of the device, and 12 is a base of the tray. A sheet original separation/feeding mechanism 13 is provided on the side, and 13 is a tilting mechanism that closes against the entire top surface of the platen 2 of the image reading device A around a fulcrum (hinge portion, not shown) on the rear side. The main body of the ADF device has a built-in housing that can be operated freely and rotated to open and open, a sheet original conveying belt mechanism 14, a sheet original discharging mechanism 15, and the like.

When automatically feeding sheet originals and reading images using ADF device B, sheet original 0 is stacked and set on sheet original setting tray 11 with the image side facing downward. The ADF device main body housing is closed on the platen z of the image reading device A and laid down as shown in the figure.

Based on the image reading start signal, the stacked document 0 on the tray 11 is
is fed by the rotation of the pickup roller 12a, and only the highest or lowest sheet document is separated into sheet documents by the sheet document 1 separation belt (or roller) mechanism 12b, passes through the conveyance roller 12c, and is transferred to the platen 2. , conveyor belt 1
4a.

The conveyor belt 14a is in contact with the top surface of the platen 2 and rotated in the direction of the arrow, and the above-mentioned introduced document is conveyed over the platen 2 from the right side of the platen to the left side by the rotational force of the conveyor belt 14a. be done. When the leading edge (left side) of the transported document reaches a predetermined reference position P on the left side of the platen 2, the rotation of the transport belt 14a is stopped. As a result, the sheet original is automatically conveyed and set at a predetermined position on the platen 2 with the image surface facing downward.

Next, the document illumination lamp 4 on the side of the image reading device A is turned on, and the forward movement of the lamp 4 and the movable first to third mirrors 5 to 7 is started, so that the downward image surface of the set document on the platen 2 is on the left side. The document is optically scanned sequentially from the side to the right side, and the illumination reflected light from the document surface is imaged on the CCD array 9 via the first to third mirrors 5 to 7 and the imaging lens 8, and sequentially enters the CCD array 9. As a result, the CCD array 9 sequentially photoelectrically reads the original image, and the CCD array 9 outputs a time-series electric digital pixel signal S corresponding to the original image.

In the case of a facsimile system, this time-series electrical digital pixel signal S is transmitted to the receiving device by wire or wirelessly,
In the case of an image reader, copying machine, etc., a display device such as a CR paper, or a storage device built into the image reading device or separate from the image reading device.

Sent to a laser beam printer, etc.

When the image reading process of the document on the platen 2 is completed, based on the completion signal, the transport bell (14a) on the ADF device B side is activated.
is rotated again, and as a result, the original on the platen 2 is ejected and conveyed to the left side of the platen 2, passes through the ejection rollers 15a and 15b of the ejection mechanism 15, and is deposited on the upper surface 13a of the ADF device main mechanism 13. The next sheet of the original on the tray 11 is placed onto the platen 2 through the automatic feeding tube in place of the ejection movement of this original, which is ejected with the upper surface as the ejection stacker section.

Wood that cannot be fed with the ADF device (book), O-2a
In the case of thick originals such as sheet originals with a thickness of about 3.3 ft (30 m) or thicker, or thick originals such as three-dimensional objects, move the ADF device main body housing to platen 2.
Open and raise it from the top centering on the fulcrum on the rear side. Then, set the original on the platen z with its left side aligned with the reference position P, with the image surface facing downward, and if possible, place the original on top of it using the A11)F device main body housing 13 as a document holder. Cover.

Next, when the image reading start button is pressed, the scanning optical systems 4 to 7 on the image reading device A side move back and forth, and the image reading of the original is performed in the same manner as in the case of the sheet original. In the case of a sheet original that can be fed directionally by the ADF device, the image can be read by manually placing the original at a predetermined position on the platen 2, as in the case of this thick original.

[Problem that the invention seeks to solve]

(1) This is a problem especially when used as a facsimile machine. When a thick document is placed on the platen, the placement reference member (scale member) cannot be placed on the platen.
It is difficult to accurately position RM because it has to be placed and set using as a guide.

(b) Sheet document 0 is also conveyed and positioned on the platen 2 depending only on the friction coefficient of the conveyor belt 14a, so skewing and misalignment occur due to slippage, making accurate positioning impossible, especially in low humidity environments. Trouble due to static electricity and unbalanced friction coefficient due to high humidity frequently occur.

With facsimiles, the image information that has been read cannot usually be confirmed by the sender, so if there is a positioning error like (a) or (b) above, information will be lost, causing great inconvenience to the recipient, and causing phone calls. Extra work is required, such as sending a contact message again.

(2) Since originals drawn with a pencil are also used, the conveyor belt 14a is easily soiled. This is because the conveyor belt is made of a material such as rubber in order to ensure a coefficient of friction for conveyance. For this reason, transparent paper or semi-transparent paper (for example, O
When a sheet such as a HP sheet or a second original drawing is read, the dirt on the surface of the conveyor belt 14a may be removed, resulting in a clean image. Not only is this difficult for the recipient to read, but unnecessary information is also transmitted, which increases communication time and increases communication costs.

The present invention aims to solve the above-mentioned problems, and provides a document positioning means suitable for facsimile machines and the like, and furthermore, a means for guaranteeing the reliability of the image quality of transparent/semi-transparent paper. It provides:

Summary: Structure of the Invention [Means for Solving Problems] The present invention provides an image reading system having a platen on which a thick original can be placed, and an automatic sheet original feeding device that feeds the sheet original to the surface of the platen. In the device, the platen is divided into a wide platen area surface where thick originals can be placed in the R position and a narrow platen area surface with the thick original placement reference ruler member as the boundary, and the platen is divided into a wide platen area surface where thick originals can be placed in the R position and a narrow platen area surface. To read a sheet original image, the sheet original is fed and moved by the apparatus at a predetermined speed with respect to the surface of the narrow platen area, and the image is read by a scanning optical system in a stationary state. An original is placed stationary on the surface of the wide platen area at a predetermined surface position with reference to the placement reference ruler member, and the scanning optical system is moved with respect to the still placed original.

The gist of the present invention is an image reading device characterized by having the following configuration.

[For production]

That is, since there is a placement reference member on the platen surface for thick originals, this is used to accurately position the original at a predetermined position on the wide platen area surface.

can be

For sheet documents that are automatically fed by an ADF device, the feeding posture of the sheet documents relative to the surface of the narrow platen area is determined only by the transport roller and discharge roller of the ADF device. It is possible.

By equipping the wide platen area where thick originals are placed with a document crimping plate that can be opened and closed freely, and by making the inner surface of the crimping plate a white surface using a stain-resistant white material, the ADF device automatically feeds the document into a narrow area. The inner surface of the guide plate, which corresponds to the back side of the sheet document that passes through the platen area, is made of a stain-resistant white material to provide a white surface, allowing for clean image reading even if the document is transparent/semi-transparent. can be set.

〔Example〕

1 to 6 show an embodiment of the present invention, and members common to those of the prior art example (FIG. 7) described above are given the same reference numerals and repeated explanations will be omitted.

ADF device device Machine Image reading device A Rotate the entire upper surface of the platen 2 of the image reading device A around the hinge portion 20 (FIG. 3) on the rear side as shown by the solid line in FIG. It can be rotated freely (Figures 1 and 2).

Inside the left side of the ADF device housing 13, there are built-in a pickup roller 12a, a sheet document 1 gl feeding mechanism 12b, a conveyance roller 12c, a slit opening 21, a paper discharge roller 15a, and the like.

FIG. 4 is a plan view of a portion of the platen 2 on the side of the image reading device A, and reference numeral 27 denotes a thick document placement reference ruler member provided near the left side of the upper surface of the platen 2 in parallel with the left side.

The upper surface of the platen 2 is divided by the ruler member 27 into a wide platen area surface I on which a thick original can be placed and set, and a narrow platen area surface (2). Reference numeral 28 denotes an auxiliary ruler member provided at right angles to the ruler member 27 on the upper surface of the rear side of the wide platen area surface I.

A sponge cushion layer 16b is provided as the document pressure bonding plate portion 16 on the lower surface side of the ADF device device housing 13 corresponding to the surface of the wide platen area, and a white sheet material 16 is further provided on the inner surface of the sponge cushion layer 16b.
C is laminated. This white sheet material 16C can be made of a material such as plastic, so it is hard to get dirty.

Also, the ADF mechanism 12a, 12b-12c# of the machine housing 13
21e The upper surface part 13b excluding the built-in part of 15a is used as a sheet original set tray part as a sheet original placement position of the ADF device, and therefore, the sheet original set tray part is located above the platen 2 of the image reading device A. It is a relationship.

Reference numeral 25 denotes a paper discharge tray as a sheet document discharge stacker, which is detachably disposed on the left side of the top plate of the image reading device A.

When using the ADF device to automatically feed sheet documents and read images, the ADF device should be folded down onto the platen 2 of the image reading device A (Fig. 102). The slit opening 21 on the B side faces the upper surface portion of the narrow platen area surface H near the left side of the platen 2 with this portion position as the image reading position MX. This image reading position corresponds to the home position of the movable first mirror 5. Sheet M document 0 is placed on the set tray section 13b with the image surface facing downward. The paper discharge tray 25 is kept attached to the image reading device A.

Based on the image reading start signal, the stacked document 0 on the tray 13b is fed by the rotation of the pickup roller 12a.
Only the uppermost original sheet is separated into single sheets by the mechanism 12b, and fed to the slit opening 21 at a predetermined speed via the conveyance roller 12c, with the downward image surface of the fed sheet original facing the slit opening 21. The discharge roller 15a passes closely to the upper surface of the narrow platen area surface H, and then the discharge roller 15a
As a result, the paper is ejected onto the paper ejection tray 25 with the image surface facing downward. That is, the sheet original is conveyed from the sheet original placement position 13b to the sheet output stacker section 25 via the sheet original image reading position 1X (21) without being reversed.

On the other hand, the movable mirror systems 5 to 7 including the illumination lamp 4 on the side of the image reading device A are kept stationary at the home position shown by the solid line, and the lamp 4 is turned on.

As a result, the downward image surface of the fed sheet document is illuminated by the lamp 4 in the process of successively passing through the slit opening 21 while closely contacting the upper surface of the narrow platen area surface H, and the image surface from the document surface is illuminated by the lamp 4. 1st~ when the reflected lighting light is stationary
The light is imaged and incident on the CCD array 9 via the third mirrors 5, 6, and 7 and the lens 8. As a result, the CCD array 9 sequentially photoelectrically reads the original image (sheet original moving reading mode), and the CCD array 9 outputs a time-series electric digital pixel signal S corresponding to the original image.

FIG. 5 is an enlarged view of the sheet document reading position X corresponding to the slit opening 21 of the ADF MB. The sheet is guided along the upper surface of the platen corresponding to the slit opening 21, and due to the stiffness of the sheet, the sheet slides in close contact with the upper surface of the platen. The paper is smoothly scooped up and guided toward the paper discharge roller 15a.

The inner surface (lower surface) of the sheet guide plate portion 24 at position X, that is, the back side of the slit opening 21, is treated with a white background 24&, and due to the presence of this white background portion 24a, it can be used even for transparent or translucent sheet originals. The image is designed to avoid background smudges. Moreover, since this white background @24a can be made of a material such as plastic, it is not easily soiled.

^To enlarge the inside of the DF mechanism 12ae12b*12c*21e15a, open and raise the upper part of the DF mechanism 12ae12b*12c*21e15a as shown in Fig. It is designed so that it can be opened, so that the jammed paper can be easily taken out and removed.

In the case of image reading of a thick original, open the ADF unit MB from above the platen 2 of the image reading unit MA (Fig. 3), place the original on the wide platen area surface, and place the left side of the original on the reference ruler member 27. Place the pressure bonding plate against the right side position Y and the back side against the auxiliary ruler member 28 so that they match and place the image surface facing downward, and if necessary, place the ADF device B over it and press the pressure bonding plate. It is held down with part 16 (16bφ160).

Next, when the image reading start button is pressed, the movable mirrors 5, 6, and 7 including the lamp 4 move forward from their home positions along the bottom surface of the platen 2 toward the right side of the platen, and move the platen 2 ( Wide platen area surface■
) The downward facing image surface of the RF11 set document above is sequentially optically scanned from the left side to the right side and photoelectrically read by the CCD array 9. Lamp 4, first to third mirrors 5 and 6
- When 7 reaches a predetermined forward movement end point 4 to 7, it is turned into a backward movement and returned to the initial home position.

In FIG. 1, the document 0 is sent by the pickup roller 12a in order from the topmost sheet, so it will be sent from the last page. Alternatively, the pickup roller L2a may be omitted and the single-sheet separation and feeding mechanism 12b may be provided with a pickup function so that the sheets are fed from the lowest page, that is, from the first page.

The auxiliary ruler member 28 may be omitted, and the reference for placing and setting a thick original (or a sheet original) for a wide platen area painter may be a so-called central reference.

Thus, it is possible to easily and accurately position a thick document at a predetermined position on the wide platen area on which the document is placed by means of the reference ruler member 27. The provision of the auxiliary ruler member 28 makes it even easier.

The sheet original is determined only by the transport roller 12C4 and the paper ejection roller 15a, regardless of the reading position of the thick original.
Accurate tip positioning and skew prevention are possible.

In addition, the inner layer 16c of the pressure bonding plate 16 is not made of rubber but is made of an opaque white plastic material, so it does not easily get dirty.Therefore, when reading transparent/semi-transparent originals, the image does not become smudged. Since it is placed outside the thick original reading area, the entire thick original reading area can be covered with the pressure bonding plate 16, and the image will not be partially smudged. It becomes impossible to cover the entire back surface of a thick document with the pressure bonding plate 16, and when a transparent/semitransparent thick document is used, the image will be smeared due to the influence of the back surface.

In addition, when reading a sheet document, it is read in the
The white background portion 24a does not need to be made of a rubber-based material, and can be made of a plasti-based material, so that it is not easily soiled.

Also, the scraper 2 is lower than the edge 2a of the platen 2.
3, the sheet document is scooped out, so that the sheet document feeding stability is also very high.

C. Effects of the Invention As described above, according to the present invention, various problems of the conventional device are solved, and high positioning accuracy and clean images can be obtained for both thick and sheet documents. can ensure that the intended objectives are well achieved.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view of an embodiment of the device of the present invention, Fig. 2 is an external oblique view of the entire device, Fig. 3 is a partially cutaway side view of the ADF device in the open and raised state, and Fig. 4 is A plan view of the platen portion, No. 5 VgJ is an enlarged view of the sheet original reading position portion, FIG. 6 is a longitudinal sectional front view with the inside of the ADF device opened, and FIG. 7 is a longitudinal sectional front view of the conventional device. A is an image reading device, B is an ADF device. Figure 2 A Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) In an image reading device that has a platen on which a thick original can be placed and a sheet original automatic feeder that feeds the sheet original to the platen surface, the platen is placed at the thick original placement reference ruler member. The platen area is divided into a wide platen area where thick originals can be placed and set, and a narrow platen area, and when a sheet original image is read using a sheet original automatic feeding device, the sheet original is transferred to the narrow platen by the device. An image is read by a scanning optical system in a stationary state while being fed and moved at a predetermined speed with respect to the area surface, and when reading a thick original image, the thick original is placed on the wide platen area surface with reference to the placement reference ruler member. What is claimed is: 1. An image reading device characterized in that the image reading device is configured to perform scanning by moving an optical system relative to the still placed original document and placing the original document stationary at a predetermined surface position.