JPH01133467A - Picture reader - Google Patents

Abstract

PURPOSE:To attain correct picture reading by providing an interval holding means to hold constantly the distance of the picture reading surface of a picture reading means and an original of an original mounting part. CONSTITUTION:An original mounting part 3 is horizontally arranged on the upper surface of a device main body 2. A picture reading means 7 is moved in the horizontal direction at the lower side of a conveyed body 6 to constitute the original mounting part 3 and one of an original conveying means 4 and the reading scanning for the original on the original mounting part 3 and the original conveyed by the conveyed body 6 is executed. The picture reading means 7 is driven by a driving part 8. The distance between the picture reading means 7 and the original mounting part 3 is constantly held by an interval holding means 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an image reading device used in an image reading section of an electronic copying machine or the like.

(Prior Art) Generally, in an electronic copying machine, image information attached to a document is read and scanned by an image reading means equipped with an exposure lamp, a Selfox lens as an imaging lens, and a reading sensor. The read image information is used for image formation.

A conventional example of an image reading device equipped with such an image reading means will be described with reference to FIG.

An image reading device 100 shown in the figure has a guide roller 102 attached to one end side of an image reading means 101 incorporating various elements such as the Selfox lens, and this guide roller 112 is brought into sliding contact with a rail 103. , one guide bar 104 is provided on the other end side of the image reading means 111.
The image reading means 101 is connected to a wire 105 which is loosely fitted into the image reading means 101 and arranged along the other end side.

Then, the wire 105 is driven by a drive means (not shown), and the image reading means 101 is made to travel along the guide bar 104 in the direction A' or direction B' in the figure. A reading operation is performed on a document placed on a glass (glass) 106.

In such an image reading device 100, when a contact sensor is used as a reading sensor and image information is formed on the sensor surface of the contact sensor using a Selfox lens,
Since the depth of focus of the Selfox lens is shallow, it is necessary to make the positional relationships between the document placement section 106 and the Selfox lens, and between the document placement section 106 and the contact sensor highly accurate.

However, in the case of the image reading device 100 described above, the positional accuracy of the SELFOX lens and contact sensor with respect to the document placement section 106 depends on the rigidity of the guide bar 104 and the adjustment of the assembly accuracy of the guide bar 104ζ with the document placement section 106. As a result, there are problems in that the diameter of the guide bar 104 increases and the difficulty in assembling increases.

(Problems to be Solved by the Invention) As described above, in the conventional device, there are problems in that the device becomes larger and difficulty in assembly cannot be avoided.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an image reading device that can read images accurately without depending on the assembly precision of each element of the device and without increasing the size of the device. That is.

[Structure of the Invention] (Means for Solving the Problems) The present invention includes a document placement section on which a document with image information attached is placed, and a document placement section that scans the document placed on the document placement section. In an image reading device comprising an image reading means for forming an image using image information read from a document, a distance maintaining means for maintaining a constant distance between an image reading surface of the image reading means and the document on the document placement section. It is constructed by having the following.

(for production) The operation of the apparatus having the above configuration will be explained below.

When this device reads image information attached to a document, the image reading means scans the document placed on the document placement section and reads image information from the document.

At this time, the distance between the image reading surface of the image reading means and the document placement section is maintained constant by the distance maintaining means, so that the positional accuracy between the image reading means and the document can always be maintained.

(Example) The present invention will be explained in detail below.

The image reading device 1 shown in FIG.
(hereinafter referred to as "exposure glass") 3, document conveying means 4 incorporated on the side of this exposure glass 3, and said exposure glass 3.
A platen cover 5 covers an original P to which image information is attached and is placed in a fixed state, and the lower side of a conveying body (platen roller) 6 forming part of the exposure glass 3 and the original conveying means 4. An image reading means 7 that moves in the horizontal direction and reads and scans the original on the exposure glass 3 and the original P transported by the transporter 6, a drive section 8 that drives the image reading means 7, and the image reading means. 7 and the exposure glass 3 is provided.

The platen cover 5 is connected to the main body 2 of the apparatus by a connecting means so as to be openable and closable as shown in FIG. 7, which will be described later.

Here, the distance maintaining means 20 will be explained in detail with reference to FIGS. 2 and 3.

This spacing holding means 20 is a pressing traveling mechanism section comprising a leaf spring 22 provided on the bottom side of the image reading means 7 and a traveling roller 24 rotatably supported by the leaf spring 22 and traveling on the rails 15a, 15b. 16, and two sets of hemispherical guide members 23a provided on the image reading surface 7A side of the image reading means 7.

23b, 23c, and 23d, the pressing traveling mechanism section 16
By urging the image reading means 7 in the direction of the arrow Z shown in FIG. It is possible to maintain a certain positional relationship.

Further, on both sides of the platen roller 6 of the document conveying means 4, there are bearing members 25a whose lower surfaces have the same height as the lower surface of the exposure glass 3, as shown in FIG.

25b is the guide member 23a, 23b, 23c.

23d, and even when the image reading means 7 moves below the platen roller 6, the pressing traveling mechanism section 16 and the guide member 23a
, 23b, 23c, and 23d, the image reading means 7 can always maintain a constant positional relationship with respect to the platen roller 6.

Then, the exposure glass 3 and the bearing material 25a as described above,
25b, even when the image reading means 7 moves from the bottom side of the exposure glass 3 to the bottom side of the platen roller 6 or vice versa, the image reading means 7 does not vibrate up and down. As shown in FIG. 3, the exposure lamp 26. CCD sensor 27
．． This makes it possible to prevent damage to the SELFOC lens 28 and the like and the occurrence of a locked state during movement.

Next, the driving section 8 will be explained with reference to FIG. 4.

The drive unit 8 includes a single wire 9 connected in an endless manner by a joint member 10, and a drive boo 911 and five driven pulleys arranged in a substantially U-shape inside the device main body 2. A wire portion 13 is provided, which is constructed by passing a hook over a group of pulleys 12a to 12e. The image reading means 7 is arranged perpendicularly to the parallel portion of the wire section 13, and the image reading means 7 and the wire 9 are connected by fixing members 14 provided at both ends of the image reading means 7. There is.

Further, below the parallel portion of the wire portion 13, a pair of rails 15a are provided along the running direction of the wire 9.

15b is arranged, and the traveling rollers 24 of the pressing traveling mechanism section 16 constituting the spacing holding means 20 provided below both ends of the image reading means 7 run on these rails 158.15b.

The drive section 8 further includes a drive mechanism section 17 that drives the wire section 13.

As shown in FIG. 2, the drive mechanism section 17 includes a pulse motor 18, a drive pulley 19 connected to the drive shaft of the pulse motor 18, a driven pulley 11a coaxial with the drive boo 911, a drive pulley 19, The timing belt 21 is provided stretched between the driven pulleys 11a.

When the pulse motor 18 rotates in the forward and reverse directions, this rotation is transmitted to the driven pulley 11a and the driving pulley 11, and these pulleys 111, 11a rotate in the six directions or direction B shown in FIG. The reading means 7 is driven in the A' force direction and in the B' direction.

Next, travel control of the image reading means 7 will be explained with reference to FIGS. 5 and 6.

As shown in FIG. 5, a protruding plate 35 is provided outward from the side surface of the image reading means 7, and a position sensor 36 is disposed facing the travel area of the protruding plate 35. Note that this position sensor 36 is shown in FIG. 6 (a>, (
b), (C)k: Arranged at a position corresponding to the platen roller 6 as shown.

When the protruding plate 35 reaches the position shown by the two-dot chain line in FIG. 5, that is, the position facing the position sensor 36, the position sensor 36 is turned on, and at any other position, it is turned off. It is set as follows.

Here, the document reading position of the image reading means 7 will be explained.

As shown in FIG. 6(b), the image reading means 7 is connected to the device main body 2.
The reading start position in the original fixed mode is when the exposure glass 3 is located below the leftmost side of the exposure glass 3.
As shown in FIG. 6(a), the home position is when the protruding plate 35 of the image reading means 7 is located just in front of the position sensor 36, and furthermore, as shown in FIG. The position where the protruding plate 35 faces the position sensor 36 is the reading position in the document transport mode.

When the power is turned on, if the position sensor 36 is off, the image reading means 7 is moved in the six directions of arrow A' shown in FIG. 6(a), and the position where the position sensor 36 is turned on is the home position. When the power is turned on, if the position sensor 36 is on, the image reading means 7 is moved in the B′ force direction, and this position sensor 36
The position where is turned off is the home position.

At the home position described above, shading correction is performed before reading. The moving distance of the image reading means 7 from the home position to the reading start position in the document fixing mode or from the home position to the document transport mode is determined by counting the number of pulses of the pulse motor 1B. There is.

Also, switching between document fixing mode and document transport mode is as follows:
It is done as follows.

That is, the platen cover 5 is fixed at a position where its upper surface faces the entrance of the document transport means 4, as shown in FIG. 7(b), and the document P is placed on the platen cover 5. When this document is inserted into the document transport means 4, a document detection switch (not shown) provided in the document transport means 4 is turned on, and in this state, a start key provided on the operation panel (not shown) of the image forming apparatus 1 is pressed. Then, the image reading device 1 determines that the mode is document transport mode, and the image reading means 7
moves to the original scanning start position after shading correction,
Reading of the document P conveyed by the platen roller 6 is started.

In the case described above, if the document detection switch is off, the image reading device 1 determines that it is in the document fixing mode, performs shading correction after manual input of the start key, and then switches to the document fixing mode as shown in FIG. 6(b). The platen cover 5 is moved to the reading start position in the closed state shown in FIG. 7(a).
It is designed to start reading the original @P fixed below.

Note that the image reading device 1 shown in FIG.
an image forming apparatus 6 equipped with a, 61b and a paper ejection tray 62;
0 is integrated with the image reading device 1.
and the image forming device 60, for example, a document P in a fixed arrangement is created.
The electronic copying machine constitutes an electronic copying machine that performs reading and image formation on both the document and the document being transported.

Next, the operation of the apparatus having the above structure will be explained, mainly focusing on the operation of the image reading means 7 and the interval keeping means 200.

First, the operation of the image reading means 7 in the document fixing mode will be explained.

After the platen cover 5 is opened wide as shown in FIG. 7(C) and the document P with image information attached is fixedly placed on the exposure glass 3, the platen cover 5 is opened as shown in FIG. 7(a). a
Return to m state. Then press the start key on the operation panel. At this time, since the document detection switch of the document conveying means 4 remains off, the image reading device 1 determines that it is in the document fixing mode. ) is moved from the home position shown in FIG. 6(b) to the reading start position in the document fixing mode, and reading of the document P is started.

In this reading operation, the rail 15a acts on the leaf spring 22 of the pressing travel mechanism section 16.

Due to the reaction force f from 15b, the hemispherical guide member 23
Since the anoff 123d is pressed against the lower surface of the exposure glass 3, the distance between the image reading surface 7A of the image reading means 7 and the lower surface of the exposure glass 3 is determined by the warpage of the exposure glass 3 and the image reading means 7. is always constant regardless of the assembly accuracy of the CCD sensor 27. of the image reading means 7. This original IP can be read and scanned while the distance of the SELFOX lens 28 to the original P on the exposure glass 3 is always kept constant.

On the other hand, the operation in the document transport mode is as follows. The platen cover 5 is opened to face the entrance of the document transport means 4 as shown in FIG. 7(b), and the document is inserted into the document transport means 4 from above the platen cover 5. Then, the original detection switch provided in the original transport means 4 is turned on, and in this state, the start key on the operation panel is pressed.

As a result, the image reading device 1 determines that it is in document transport mode, and
After the shading correction, the image reading means 7 is conveyed by the drive section 8 to the reading start position shown in FIG. 6(C), and starts reading the document conveyed by the platen roller 6.

At this time, the guide member 23a of the image reading means 7.

23b, 23c, and 23d are bearing members 24 on the platen roller 6 side due to the pressing force of the leaf spring 22 of the pressing traveling mechanism section 16.
a, 24b, the exposure lamp 26 of the image reading means 7 is
．． The CCD sensor 27 and the self-ox lens 28 always maintain a constant positional relationship with respect to the document conveying surface of the platen roller 6.

Roughly speaking, even when the image reading means 7 is moved by switching between the document fixing mode and the document transport mode, the lower surface of the exposure glass 3 and the lower surfaces of the bearing members 24a and 24b are installed at the same height. Image reading means 7 passing through this joint end
There is almost no impact on the guide members 23a, 23b, 23c, 23d due to the exposure lamp 26.
CCD sensor 27. It is possible to prevent damage to the SELFOX lens 28 and the like and occurrence of a locked state.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the invention.

[Effects of the Invention] According to the present invention described in detail above, the distance between the image reading surface of the image reading means and the document can always be kept constant by the action of the distance maintaining means, and the assembly of each element of this device is easy. It is possible to provide an image reading device that exhibits stable reading operations without depending on accuracy and without increasing the size of the device in the future.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention, FIG. 2 is a cutaway sectional view showing the arrangement of the image reading means, exposure glass, and bearing material in the same device, and FIG. 3 is an image reading device of the same device. FIG. 4 is a perspective view showing the image reading means of the device and its driving section; FIG. 5 is a partial cross-sectional view showing the positional relationship between the device, the exposure glass, and the document; FIG. 5 is the relationship between the image reading device and the position sensor of the device. Perspective views showing FIGS. 6(a), (b),
7(C) is an explanatory diagram showing the home position of the image reading means, the reading position in document fixing mode, and the reading position in document transport mode in the same apparatus, FIGS. 7(a) and 7(b), respectively. (C) is a perspective view showing the closed state, paper feeding state, and open state of the platen cover in a device that combines an image reading device and an image forming device, respectively, and FIG. 8 shows the configuration of the image reading means of the conventional device. FIG. P... Document, 1... Image forming device, 3... Document placement section, 7... Image reading means, 7A... Image reading surface, 20... Interval holding means.

Claims (2)

[Claims] (1) A document placement section on which a document with image information attached is placed, and an image reading means that scans the document placed on the document placement section and uses the image information read from the document for image formation. What is claimed is: 1. An image reading apparatus comprising: a distance maintaining means for maintaining a constant distance between an image reading surface of the image reading means and a document on the document placing section. (2) The distance maintaining means includes a guide member disposed on the image reading surface side of the image reading means, and a pressing traveling mechanism that presses the guide member toward the document placement section. The image reading device according to scope 1.