JPH07193689A - Reader - Google Patents

Abstract

PURPOSE:To always match a focus onto a source document face by obtaining stably an optimum focus of a contact type image sensor. CONSTITUTION:A roll 3 is provided to a contact type image sensor 2, the roll 3 is in close contact with a lower face of an source document platen glass 1, and a compression spring pressing the contact type image sensor 2 onto the source document platen glass 1 is provided to a running body 4 supporting the contact type image sensor 2 in the vertical motion only. The interval with the source document platen glass 1 is kept constant by the use of the roll 3 during the movement of the running body 4 at reading.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading device for reading document image information using a contact image sensor.

[0002]

2. Description of the Related Art Conventionally, in a book-compatible scanner (reading device) for reading document image information with a document fixed,
The CCD image sensor was overwhelmingly advantageous over the contact image sensor. The reason is that the CCD image sensor has a deep depth of focus, and the corresponding process is fast.

However, due to the improvement of the contact type image sensor, the processing speed is now inferior to that of the CCD image sensor, and the RMLA (roof
It has been improved to 0.5-0.6 mm due to the development of mirrors, lenses and arrays.

[0004]

As described above, if the contact type image sensor is equivalent to the CCD image sensor in terms of performance, it is more advantageous to use the contact type image sensor in a book-compatible scanner. is there.

For example, in the outer shape, the thickness can be reduced to approximately half, the drive system is greatly simplified, and adjustment is almost unnecessary, and the image is not distorted by the reduction optical system.

However, although the contact image sensor has the above-mentioned advantages, if the support structure of the contact image sensor is not accurate, the optimum focus is not stable and accurate image information cannot be read. There is a problem that is not done.

An object of the present invention is to provide a reading device in which the optimum focus of the contact image sensor can be stably obtained and the original surface is always in focus.

[0008]

In order to achieve the above object, the present invention reads a document image information by using a contact type image sensor that reciprocates below the document table glass on which the document is placed. The apparatus is characterized by including a spacer that holds a constant distance between the document table glass and the contact image sensor, and a pressing member that presses the contact image sensor against the document table glass via the spacer. .

In the reading device, a traveling body that supports the contact-type image sensor so that it can move only up and down, and a distance between the platen glass and the contact-type image sensor that are provided in the contact-type image sensor are kept constant. A spacer,
It is characterized by comprising a pressing member which is provided on the traveling body and presses the contact type image sensor against the original platen glass via the spacer, and a driving body which moves the traveling body together with the contact type image sensor.

Further, in the above-mentioned reading device, the contact type image sensor is provided with a spacer for keeping a constant distance from the platen glass, and the spacer is provided between the bracket for supporting the tire rolling on the support and the contact type image sensor. A compression spring is provided, and a driver for moving the contact image sensor is further provided.

Further, the spacer is a roller which comes into rolling contact with the platen glass.

Further, the spacer is a sliding member made of a highly slippery material.

Further, the spacer is a convex portion projecting from a part of the housing of the contact image sensor.

[0014]

In the reading device having the above structure, the distance between the original platen glass on which the original is placed and the contact image sensor is kept constant by the spacer or the roller, and the contact image sensor is pressed by the pressing member or the compression spring. The gap is maintained by pressing and urging the sheet toward the platen glass.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front sectional view of an essential part of a first embodiment of the present invention, and FIG. 2 is a side sectional view of the first embodiment. Reference numeral 1 is an original table glass on which an original is placed. Is a known contact-type image sensor, 3 is a roller that is rotatably provided in the housing of the contact-type image sensor 2, and 4 is a box-like shape in which the contact-type image sensor 2 is freely stored only in the vertical direction. A traveling body 5 is a compression spring which is a pressing member for upwardly pressing the contact type image sensor 2 partly protruding from the upper opening of the traveling body 4, and 6 is a platen glass 1
Is an outer case that is fixed to the top.

Reference numeral 10 denotes a lead shaft which is a driving body which meshes with a receiving portion 4a on one side of the traveling body 4 and is rotated by the rotation of a motor (not shown) to move the traveling body 4 in a predetermined direction. Reference numeral 11 denotes a rail body that engages with the other side portion 4b of the traveling body 4 and guides the movement of the traveling body 4.

In the first embodiment, the contact type image sensor 2 is biased by the compression spring 5 so as to press the original platen glass 1 via the roller 3, and the roller 3 is the lower surface of the original platen glass 1. The depth of focus A is always kept constant by touching. The fluctuation of the object distance when the contact type image sensor 2 is read in the sub-scanning direction is
Even if the rail body 11 and the lead shaft 10 are deformed, the flatness of the platen glass 1 determines the flatness of the platen glass 1 and can be ignored.

At the time of reading, by rotating the lead shaft 10, the contact-type image sensor 2 moves in parallel with the traveling body 4 below the original platen glass 1. During this movement, in the contact image sensor 2, the roller 3 comes into contact with the original platen glass 1 while rolling to maintain a constant depth of focus A, so that the original surface is always optimally focused. As a result, good document reading is performed.

FIG. 3 is a front sectional view of an essential part of the second embodiment of the present invention, and FIG. 4 is a side sectional view of the second embodiment.
In the embodiment, similarly to the first embodiment, the roller 3 which contacts the lower surface of the original platen glass 1 in the housing of the contact image sensor 2 is used.
Is rotatably provided, 20 is a tire that rolls on the inner wall of the outer case 6 that is a support, 21 is a vertically movable bracket that rotatably supports the tire 20, and 22 is a contact image sensor 2 Is a compression spring interposed between a part of the housing of and the bracket 21.

A guide bracket 26 that meshes with the lead shaft 25 is provided on the lower surface of the housing of the contact image sensor 2.

In the second embodiment, at the time of reading, the contact image sensor 2 itself moves in parallel under the original platen glass 1 by the lead shaft 25 which is rotationally driven. During this movement, the contact type image sensor 2 can maintain a constant depth of focus A by the contact of the roller 3 with the platen glass 1. The fluctuation of the object distance when the contact type image sensor 2 is read in the sub-scanning direction can always absorb the distortion of the outer case 6 by being pressed against the platen glass 1. Further, the contact image sensor 2 receives the driving force directly by the lead shaft 25 without shifting in the sub-scanning direction.

As described above, in the second embodiment, as compared with the first embodiment, the contact type image sensor 2 itself has sufficient rigidity to simplify the drive mechanism, so that the traveling body and Parts such as rails can be deleted, cost can be reduced, and the external height of the device can be suppressed.

In FIG. 5, instead of the rollers 3 which are the spacers of the first and second embodiments, sliding brackets 30 which come into contact with the platen glass 1 are projected from both sides of the contact image sensor 2. . Considering the sliding resistance, the sliding bracket 30 is preferably made of a highly slippery material such as polyfluorinated ethylene resin.

FIG. 6 shows the contact type image sensor 2 in which the housing 31 is directly provided with a convex portion 31 which comes into contact with the original platen glass 1. At least the convex portion 31 may be made of the highly slippery material.

By using the sliding bracket 30 and the convex portion 31 instead of the roller 3 as a spacer as described above, the structure can be further simplified, and the size and cost can be reduced.

[0027]

As described above, according to the invention of claim 1, the reading device of the present invention is optimal because the distance between the platen glass and the contact image sensor can be kept constant by the spacer. A stable focus is obtained, and good originals can be read.

According to the second aspect of the present invention, since the traveling body moves while the contact type image sensor is held by the spacer with respect to the platen glass at a constant interval, stable reading can be performed.

According to the third aspect of the present invention, the contact type image sensor itself moves with respect to the platen glass while maintaining a constant space by the spacer, so that stable reading can be performed with a simple structure.

According to the fourth aspect of the present invention, since the rollers are used as the spacers, the contact resistance is small, and the distance between the platen glass and the contact image sensor can be reliably maintained for a long period of time.

According to the fifth and sixth aspects of the present invention, the space can be replaced by the roller and the protrusions or the sliding member made of a highly slippery material can be used to simplify the structure of the spacer and reduce the size. The cost can be reduced.

[Brief description of drawings]

FIG. 1 is a front sectional view of a main part of a first embodiment of a reading device of the present invention.

FIG. 2 is a side sectional view of the first embodiment.

FIG. 3 is a front sectional view of a main part in a second embodiment of the present invention.

FIG. 4 is a side sectional view of a second embodiment.

FIG. 5 is a perspective view of a contact image sensor showing another example of a spacer.

FIG. 6 is a perspective view of a contact image sensor showing another example of a spacer.

[Explanation of symbols]

1 ... Platen glass, 2 ... Contact image sensor, 3
... Roller (spacer), 4 ... Running body, 5,22 ... Compression spring (pressing member), 6 ... Outer case (supporting body), 10,25 ...
Lead shaft (driving body), 20 ... Tire, 21 ... Bracket, 30 ... Sliding bracket, 31 ... Convex part.

Claims (6)

[Claims] 1. A reading device for reading document image information by using a contact type image sensor which reciprocates under a document platen glass on which an original document is placed, and a gap between the document platen glass and the contact type image sensor. And a pressing member that presses the contact image sensor against the platen glass via the spacer. 2. A reading device for reading image data of a document by using a contact image sensor that reciprocates below a document table glass on which a document is placed, and supports the contact image sensor so that it can move only up and down. And a spacer provided on the contact type image sensor for maintaining a constant distance between the platen glass and the contact type image sensor; and a contact type image sensor provided on the running body via the spacer. A reading device comprising: a pressing member that presses against a platen glass; and a driving body that moves the traveling body together with a contact image sensor. 3. A reading device for reading document image information using a contact type image sensor that reciprocates under a document platen glass on which an original is placed, wherein the contact type image sensor is connected to the document platen glass. A spacer is provided to keep the spacing constant, and a compression spring is provided between the bracket for supporting the tire rolling on the support and the contact image sensor, and a driver for moving the contact image sensor is provided. A reading device characterized in that 4. The reading device according to claim 1, wherein the spacer is a roller that comes into rolling contact with the platen glass. 5. The reading device according to claim 1, wherein the spacer is a sliding member made of a highly slippery material. 6. The reading device according to claim 1, wherein the spacer is a convex portion projecting from a part of the housing of the contact image sensor.