JPH0520039Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an image reading device, and more specifically, the invention is related to an image reading device, in which a document is fed along a conveyance path, and the document is passed through a contact glass provided on the conveyance path. The present invention relates to an image reading device that reads images.

(Prior art) Image reading devices include a reading method in which an optical system moves relative to a fixed document to read an image for one page of the document, and a reading method in which the optical system is fixed and the document is moved relative to the optical system. There is a reading method that moves and reads the image of one page of the original.

Among these, image reading devices that use a reading method that moves the original without moving the optical system have, for example, a conveying path for the original 2 formed by a guide member 1, as shown in FIG. guide member 1
A contact glass 3 is fitted in the. Contact glass 3 is held by guide member 1. That is, the guide member 1 is divided into a front guide member 1a and a rear guide member 1b, and the front guide member 1a and the rear guide member 1b are separated by a predetermined distance in the direction in which the document 2 is conveyed. Stepped sections 4 and 5 are formed at the rear end of the front guide member 1a and the front end of the rear guide member 1b, and the contact glass 3 is held by the step sections 4 and 5. There is. The contact glass 3 is pressed from above against the stepped portions 4 and 5 at both ends in the sub-scanning direction by biasing members such as plate springs (not shown), thereby preventing the contact glass 3 from floating. A pressure plate 6 is disposed above the contact glass 3, and the pressure plate 6 brings the original 2 into close contact with the contact glass 3. When the original 2 is fed between the contact glass 3 and the pressure plate 6, light from a light (not shown) provided below the contact glass 3 is projected onto the original 2 through the contact glass 3. The reflected light is converted into a photoelectric converter (e.g. CCD).
(Charge Coupled Device) etc. to receive light and read the image.

However, in such a conventional image reading device, the guide member 1 is placed on the stepped portions 4 and 5;
Since the original was configured to be pressed down from above by a biasing member such as a leaf spring, when the original 2 was fed to the contact glass 3, the leading edge of the original 2
As shown by the broken line in FIG. 4, the front guide member 1
There was a problem that the contact glass 3 entered the gap between the contact glass 3 and the document 2, resulting in poor conveyance of the document 2.
This is particularly likely to occur when the gap between the front guide member 1a and the contact glass 3 becomes large due to vibrations, etc.
Even when a gap as shown in FIG. 5 is created between the front guide member 1a and the contact glass 3 due to the warpage, the document 2 will enter this gap and cause a conveyance failure.

(Purpose of the invention) Therefore, the present invention has the purpose of sandwiching the end of the contact glass between the tongue and the receiving part to smoothly guide the document from the front guide member onto the contact glass through the tongue, and to It is possible to prevent the contact glass from lifting or rattling due to warpage of the side guide member or the rear guide member, and prevent the original from entering between the front guide member and the contact glass, improving the transportability of the original. It is an object of the present invention to provide an image reading device that can improve the accuracy of document reading by correctly reading images.

(Structure of the Invention) In order to achieve the above object, the present invention conveys an original on a guide member, and scans light onto the original surface through a contact glass fitted in the middle of the guide member to create an image. In an image reading device that reads
The document conveyance direction guide member of the contact glass is provided with a tongue extending above the contact glass and a receiving portion extending below the contact glass. An inclined surface is formed that slopes upward from the front side toward the central portion, the inclined surface is brought into contact with the tongue of the guide member, and the end of the contact glass is sandwiched between the tongue and the receiving portion. It is characterized by the following.

Hereinafter, the present invention will be explained in detail based on embodiments.

1 to 3 are diagrams showing an embodiment of the present invention, which is applied to a facsimile machine.

In FIG. 1, reference numeral 11 denotes a facsimile device, and the facsimile device 11 includes a power supply and communication control section 13, an image recording section 14, an image reading section 15, etc. in a main body 12.

The communication control unit 13 controls communication with an external line, and also controls the operations of the image recording unit 14, the image reading unit (image reading device) 15, and the like. The image recording section 14 includes a light source 16, a liquid crystal shutter array 17,
It includes a lens 18, a photosensitive drum 19, a charging section 20, a developing section 21, a transfer section 22, a fixing section 23, a static eliminating section 24, and the like.

The light projected from the light source 16 is focused onto the photosensitive drum 19 by the lens 18, and this projected light is
A liquid crystal shutter array 17 disposed between a light source 16 and a lens 18 controls whether or not to illuminate the photosensitive drum 19 for each pixel. That is, the liquid crystal shutter array 17 is controlled pixel by pixel based on the received signal from the other party's facsimile machine and the read signal from the image reading section 15, and passes or blocks the light from the light source 16 and projects it onto the photosensitive drum 19. An exposed area and a non-exposed area are formed.

The photosensitive drum 19 is a cylindrical conductive support with a photoconductive material (e.g., Se, Se-Te, etc.) adhered to the surface.It is a good insulator in the dark and retains charge, but does not absorb light. When irradiated, the electrical resistance decreases and the surface charge dissipates quickly. That is, when the uniformly positively charged surface of the photosensitive drum 19 is irradiated with light, the charge on the exposed portion disappears, and an electrostatic latent image is formed on the surface of the photosensitive drum 19.

The developing section 21 includes a case 25 and a magnetic roll 26 rotatably supported within the case 25, and the case 25 is filled with toner. Toner is a developer, for example, 5μm plastic resin containing about 5% carbon.
It has a negative charge. The toner uniformly adheres to the magnetic roll 26, and when it rotates and approaches the photosensitive drum 19, the toner adheres to a portion of the photosensitive drum 19 that is charged to the opposite polarity to the toner and is developed. The transfer unit 22 applies positive corona to the back surface of the recording paper 27 that is fed between the photosensitive drum 19 and the transfer unit 22, and transfers the toner attached to the photosensitive drum 19 onto the recording paper 27. Fixing section 23
The recording paper 27 on which the toner has been transferred is subjected to processing such as heating to dissolve the toner, and is fixed on the recording paper 27 for permanent recording.

The charge eliminating section 24 eliminates the charge from the photosensitive drum 19 to erase the electrostatic latent image, and the charging section 20 uniformly applies a positive charge to the surface of the photosensitive drum 19. The recording paper 27 is stored in a cassette 28, and the recording paper 27 is stored in a cassette 28.
9 is sent out. The recording paper 27 sent out from the cassette 28 is fed by a feed roller 30, transferred and fixed, and then ejected to a copy tray 32 by a delivery roller 31. The recording paper 27 in the cassette 28 is placed on a bottom plate 33, and is urged toward the feed roller 29 by a spring 34.

The image reading section 15 includes a light source 35, a mirror 36, a contact glass 37, a pressure plate 38, a photoelectric conversion section 39, and the like, and reads an image written on a document 40.

A document table 41 is provided at the top of the main body 12 , and the document 40 placed on the document table 41 is separated one by one by a conveyance roller 42 and then sent to a reading section 44 by a feed roller 43 . The document 40 read by the reading section 44 is discharged onto a document tray 46 by a discharge roller 45 . Further, a separation plate 47 is provided above the conveyance roller 42, and works together with the conveyance roller 42 to separate the documents on the document table 41 one by one. The light projected from the light source 35 is transmitted through the contact glass 37 and reflected on the surface of the original 40 , and further reflected by the mirror 25 and introduced into the photoelectric conversion section 39 . The photoelectric conversion section 39 includes a lens, an image sensor, etc., and the light introduced into the photoelectric conversion section 39 is focused onto the image sensor by the lens. The image sensor decomposes the image information of one line of the document 40 into a plurality of pixels and photoelectrically converts the image information, and the image information converted into an electric signal is sent to the communication control section 13.

As shown in FIGS. 2 and 3, the contact glass 37 is fitted in the middle of a guide member 48, and the guide member 48 carries the document 40 separated one by one by the conveyance roller 42 and the separation plate 47 to the reading section. 44 and document tray 46. The guide members 48 include a front guide member 48a located on the front side of the contact glass 37 with respect to the conveyance direction of the document 40, and a rear side guide member located on the rear side of the contact glass 37 with respect to the conveyance direction of the document 40. 48b, and the front guide member 48a guides the originals 40 separated one by one from the original table 41 to the reading section 44. The rear guide member 48b guides the original 40, the image of which has been read by the reading unit 44, to the original tray 46. At the end of the front guide member 48a on the contact glass 37 side, there is a receiving part 49 bent downward in a step-like manner.
Similarly, a receiving portion 50 bent downward in a stepwise manner is formed at the end of the rear guide member 48b on the contact glass 37 side. The receiving portion 49 of the front guide member 48a and the receiving portion 50 of the rear guide member 48b extend to both lower ends of the contact glass 37 in the document conveyance direction, and hold the contact glass 37 from below.

Further, a tongue portion 51 extending above the contact glass 37 is formed at the end of the front guide member 48a on the contact glass 37 side, and the tongue portion 51 has a predetermined width and is approximately parallel to the front guide member 48a. It extends over the contact glass 37. A plurality of tongue portions 51 are formed at equal intervals in a direction perpendicular to the conveyance direction of the document 40 (main scanning direction).

On the other hand, the contact glass 37 has an inclined surface 52 formed at its upper end on the near side in the conveying direction, and the inclined surface 52 is inclined upward from the near side in the conveying direction toward the center (in the conveying direction). . The tongue portion 51 is in contact with this inclined surface 52, and the front end of the contact glass 37 in the conveying direction of the document 40 is sandwiched between the receiving portion 49 and the tongue portion 51, and the rear end thereof is held by the receiving portion 50. There is.

Note that the contact glass 37 is urged downward by a plate spring or the like (not shown), and the front guide member 48
a, it is pressed against the receiving parts 49 and 50 of the rear guide member 48b.

Next, the effect will be explained.

First, an image is read by the image reading section 15. That is, the original 40 placed on the original platen 41 is separated one by one by the transport roller 42 and the separation plate 47, and is transported on the front guide member 48a toward the contact glass 37, and further,
The contact glass 37 is conveyed by the feed roller 43. When the leading edge of the original 40 reaches the gap between the front guide member 48a and the contact glass 37, the leading edge of the original 40 is guided by the tongue 51 and advances to the inclined surface 52 of the contact glass 37, where it meets the front guide member 48a. It will not get into the gap with the contact glass 37. Therefore, the original 40 is smoothly guided onto the contact glass 37 without being caught in the gap between the front guide member 48a and the contact glass 37, and the original 40 is smoothly guided onto the contact glass 37.
0 transportability is improved. Further, since the tip of the contact glass 37 is sandwiched between the receiving portion 49 and the tongue portion 51, it is possible to prevent the front edge from lifting up due to warping of the front guide member 48a and the rear guide member 48b. , the transportability of the original 40 can be further improved. In addition to this, the original 40 can be read normally,
The accuracy of reading the original 40 can be improved.

When the original 40 is conveyed onto the contact glass 37 and the first line of the original reaches the reading section 44, the light source 35
More light passes through the contact glass 37 and the original 4
The projected light is reflected by the surface of the document 40. The light reflected from the surface of the original 40 contains the image information written on the original 40, is reflected by the mirror 36, and is introduced into the photoelectric conversion unit 39.
The light introduced into the photoelectric conversion section 39 is photoelectrically converted,
The image information is sent to the communication control unit 13 as an electrical signal. The original 40 whose image has been completely read is conveyed over the rear guide portion 48b by the ejection roller 45, and is ejected onto the original tray 46.

The image information read by the image reading section 15 is subjected to signal processing by the communication control section 13 and sent to the other party's facsimile device via an external line, or is recorded on recording paper 27 by the image recording section 14.

Recording of the image is performed in the image recording section 14. That is, the photosensitive drum 19 rotates in the direction of the arrow in FIG. 1, and is first given a positive charge in the charging section 20. Next, light is emitted from the light source 16, but this light is passed through and blocked for each pixel by the liquid crystal shutter array 17, and the liquid crystal shutter array 17 transmits the light from the other party's facsimile device via an external line. image information and image reading section 15
It is controlled by the communication control section 13 based on the image information read by. When the photosensitive drum 19 is irradiated with light, the positive charge in the exposed portion disappears, and an electrostatic latent image of image information is formed on the surface of the photosensitive drum 19 . Toner is attached to the surface of the photosensitive drum 19 by the magnetic roll 26, but the toner has a negative charge and is attracted to the positive charge of the photosensitive drum 19 and adheres to the surface of the photosensitive drum 19. Therefore, toner adheres only to the positively charged portion of the photosensitive drum 19 and is developed. The toner attached to the surface of the photosensitive drum 19 is transferred to the recording paper 2 in the transfer section 22.
7 and is fixed in the fixing section 23.
The recording paper 27 is transferred from the feed roller 29 to the cassette 2.
8 , and is discharged onto a copy tray 32 through a transfer section 22 and a fixing section 23 by a feed roller 30 and a discharge roller 31 .

Although the embodiment described above is applied to a facsimile device, the present invention is not limited to this, and can be applied to any device in general that uses an image reading device that conveys an original and reads an image.

Further, the width and length of the tongue portion are not limited to those of the above-mentioned embodiments, but may be appropriately set depending on the characteristics of the device, the paper quality of the document, and the like.

Further, in the above embodiment, a case was described in which the contact glass is held by the receiving part of the guide member, but the present invention is not limited to this, and the contact glass is held by a member other than the guide member, and the tongue is placed on the contact glass. It may be an extended version.

(Effects) According to the present invention, the document is smoothly guided from the front guide member onto the contact glass through the tongue, and the contact glass is prevented from lifting or rattling due to warping of the front guide member or the rear guide member. As a result, it is possible to prevent the document from entering between the front guide member and the contact glass, and it is possible to improve the conveyance of the document. In addition, since lifting and rattling of the contact glass can be prevented, the original can be read normally, and the accuracy of reading the original can be improved.

[Brief explanation of the drawing]

1 to 3 are views showing one embodiment of the image reading device of the present invention, and FIG. 1 is a front sectional view of a facsimile device to which the image reading device is applied, and FIG.
The figure is an enlarged sectional view of the main part of the image reading apparatus, and FIG. 3 is a perspective view of the main part of the image reading apparatus. Fourth,
FIG. 5 is a diagram showing a conventional image reading device.
The figure is an enlarged sectional view of the main part, and FIG. 5 is an enlarged sectional view of the main part when the guide member of the image reading device has a warp. 15... Image reading unit (image reading device), 35...
... light source, 36 ... mirror, 37 ... contact glass, 38 ... pressure plate, 39 ... photoelectric conversion section, 40
...Original, 41...Document table, 42...Transport roller, 43...Feed roller, 44...Reading section, 45
...Discharge roller, 46...Document tray, 47...
Separation plate, {48a... Front guide member, 48b
...Rear side guide member} (guide member), 49...
Receiving portion, 51... tongue portion, 52... inclined surface.

Claims (1)

[Scope of utility model registration request] In an image reading device that conveys an original on a guide member and scans the image by scanning light on the original surface through a contact glass fitted in the middle of the guide member, the front side of the contact glass in the original transport direction is used. The guide member is provided with a tongue portion extending above the contact glass and a receiving portion extending below the contact glass, and a tongue portion extending above the contact glass and a receiving portion extending below the contact glass. The contact glass is characterized in that an inclined surface is formed that slopes upward when the contact glass is directed, the inclined surface is brought into contact with the tongue of the guide member, and the end of the contact glass is sandwiched between the tongue and the receiving portion. image reading device.