JP2002010002A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader which can prevent the quality deterioration of read images caused by dust entered into a carriage, by inexpensively preventing the flying up of dust entered into the reader. SOLUTION: Since an adhesive tape 30 is provided on the original platen-side surface of the carriage 20, dust is collected by the tape 30 when the dust entered into this picture reader 1 from heat radiating holes 14 or structural gaps falls on the original platen-side surface of the carriage 20. Therefore, the dust can be prevented from flying up or entering into the carriage 20 even when the carriage 20 is moved and the quality deterioration of a read original can be reduced. Since the adhesive tape 30 is inexpensive, the price of the reader 1 does not rise.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an image reading apparatus.

[0002]

2. Description of the Related Art Conventionally, there has been known an image reading apparatus for reading images such as characters and photographs. As an image reading apparatus, as shown in FIG. 4, a platen 102 is arranged on one surface side of a box-shaped main body 101, and a document to be read on the platen 102 is placed on a flatbed type image reading apparatus. 100 is typical.

A flatbed type image reading apparatus 10
In the case of 0, for example, a line sensor 103 in which a plurality of imaging devices such as CCDs (Charge Coupled Devices) are arranged in the main scanning direction is used as an imaging unit. The original on the original table is read by moving the carriage 104 on which the line sensor 103 is mounted at a constant speed in the sub-scanning direction.

[0004]

However, in the image reading apparatus 100 as described above, a heat radiating hole 106 for radiating heat generated from the light source 105 and the like is formed. It cannot be eliminated. Therefore, it is difficult to prevent dust from entering the inside of the image reading apparatus 100 from the heat radiation holes 106 and gaps. Part of the dust that has entered the inside of the image reading apparatus 100 falls on the surface of the carriage 104 on the document table 102 side.

The carriage 104 has a reading window 107 and a reading slit 10 for collecting light from a document.
8 are formed. Therefore, dust that has entered the image reading apparatus 100 and dropped on the surface of the carriage 104 on the platen side soars with the movement of the carriage 104, and enters the inside of the carriage 104 through the reading window 107 and the reading slit 108 when dropped. There is a possibility that.

[0006] Immediately below the reading window 107 and the reading slit 108, a mirror 10 for reflecting light from an original is provided.
9 is provided, and the dust that has fallen into the carriage 104 adheres to the mirror 109. Lens 110 for condensing light on line sensor 103
Is set so that the original placed on the original platen 102 is focused, so that dust near the original platen adversely affects the image quality of the image read. That is, since the mirror 109 is located at a position close to the document table, dust adhering to the mirror 109 greatly affects the image quality of the read image.

On the other hand, to prevent dust from adhering to the mirror 109, the reading window 107 may be shielded by a transparent member, or the airtightness of the carriage 104 may be improved. However, the addition of a transparent member to shield the reading window 107 leads to an increase in cost, which is against the recent trend toward lower prices of computer peripherals as well as image reading apparatuses. Further, when the airtightness of the carriage 104 is increased, there is a problem that it is difficult to release heat generated from the light source 105 and the like.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image reading apparatus which is inexpensive and prevents dust that has entered the inside from flying up and prevents dust from entering the inside of the carriage, thereby preventing the quality of an image to be read from deteriorating. To provide.

[0009]

According to the image reading apparatus of the present invention, dust collecting means is provided on the surface of the carriage on the document table side. The dust collection means
This prevents dust that has fallen on the surface of the carriage on the platen side from flying up with the movement of the carriage. Therefore, it is possible to prevent the soaring dust from entering the carriage when falling and adhering to the mirror near the document table. Therefore, it is possible to prevent the image quality of the image to be read from deteriorating.

According to the image reading apparatus of the present invention, an inexpensive adhesive tape or adhesive resin can be used as the dust collecting means. Therefore, it is inexpensive and does not require a complicated manufacturing process for forming the dust collecting means.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; FIG. 1 shows an image reading apparatus according to an embodiment of the present invention. As shown in FIG. 1, the image reading device 1 includes a carriage 20 inside a box-shaped main body 10. A document table 11 is provided above the main body 10.

The main body 10 includes a main body case 12 made of resin,
And a main body frame 13 made of metal. The main body case 12 further includes an upper case 121 and a lower case 122.
And is divided into: The body case 12 and the body frame 13 are provided with a plurality of heat radiation holes 14 for releasing heat generated from the inside of the body, particularly, heat generated from the carriage 20.

The carriage 20 has a carriage case 21, in which a light source 22, a mirror 23, a mirror 24, a lens unit 25, and a line sensor 26 as an image pickup means are mounted. The carriage 20 is moved by the driving means 40 as shown in FIG.
1 in the sub-scanning direction.

The carriage case 21 includes a carriage frame 211 and a carriage cover 212. Carriage frame 211 and carriage cover 2
12 is a first housing portion 27, and the first housing portion 27 has a mirror 23, a mirror 24, and a lens portion 2.
5 and a line sensor 26 are accommodated. On the carriage cover 212, a second housing portion 28 for housing the light source 22 is formed. A reading window 28 for condensing light from the document 2 is provided on the platen side of the second storage unit 28.
a is formed. On the other hand, the light that has passed through the reading window 28a is
A reading slit 28b for allowing the light to enter the inside 7 is formed. The reading window 28a and the reading slit 28b constitute an opening.

The light source 22 is arranged in the main scanning direction perpendicular to the moving direction of the carriage 20, and uses a fluorescent lamp or the like. The light emitted from the light source 22 is transmitted to the reading window 2
8a, reflected on the surface of the original 2 such as paper,
The light enters the carriage 20 again from the reading window 28a via the reading slit 28b,
Is collected.

The mirrors 23 and 24 are provided to reflect light from the document 2 condensed on the line sensor 26 and to lengthen the optical path length. The mirror 23 is disposed immediately below the reading window 28a and the reading slit 28b. The lens unit 25 has a plurality of lenses, and collects light from the document 2 on the line sensor 26. The line sensor 26 includes a plurality of pixels such as CCDs on the carriage 2.
A charge accumulation type optical sensor linearly arranged in the main scanning direction perpendicular to the moving direction of 0 is used.

A document guide is provided around the document table 11 for positioning the document 2 to be read and restricting the movement of the document 2 when reading the document. In this embodiment, the upper case 121 of the main body 10 is used as a document guide. By placing the original 2 in contact with the original guide, that is, the end 121 a of the upper case 121 on the original platen side, the placement position of the original 2 is determined. A white reference 15 having a highly reflective uniform reflection surface is provided at an end of the document table 11 in the carriage movement direction.

A processing unit 60 as shown in FIG. 2 is mounted inside the main body 10. The processing unit 60 includes a CPU (Cent
ral Processing Unit) 61, RAM (Random Access M)
emory) 62, a ROM (Read Only Memory) 63, an image processing circuit 64, and an amplifier 65. C
The PU 61 controls the entire operation of the image reading apparatus 1 such as controlling the driving of the carriage 20, controlling the blinking of the light source 22, and processing image data created by the image processing circuit 64. The RAM 62 temporarily stores image data read by the line sensor 26 and the like. ROM63 has C
A computer program for controlling each unit of the image reading apparatus 1 by the PU 61 is stored.

The image processing circuit 64 includes an A / D converter 64
1, shading correction unit 642, gamma correction unit 643
And other correction units 644. A /
The D converter 641 converts an analog electric signal output from the line sensor 26 and amplified by the amplifier 65 into a digital electric signal. The shading correction unit 642 uses the data obtained by reading the white reference 15 before starting reading with respect to the digital signal output from the A / D converter 641, and uses the data obtained by reading the white reference 15 to change the sensitivity of each element of the line sensor 26 or The variation in the light amount of the light source 22 in the main scanning direction is corrected. The gamma correction unit 643 performs gamma correction by a predetermined gamma function, and converts a shading-corrected digital light amount signal into digital image data. The other correction unit 644 performs various conversions such as color correction, edge enhancement, and area enlargement / reduction. The digital image data created by the image processing circuit 64 is
The data is output from an interface 16 provided in the main body 10 to an externally connected image processing apparatus such as the personal computer 3.

The dust collecting means is attached to the surface of the carriage 20 on the original platen side as shown in FIG. In this embodiment, the adhesive tape 30 is used as the dust collecting means. For example, an adhesive tape 30 having an adhesive applied to both sides of the tape, such as a double-sided tape, is used.

The adhesive tape 30 is attached to the carriage cover 21
2 and on the surface of the second housing portion 28 on the side opposite to the original platen. The adhesive tape 30 is, as shown in FIG.
8 is mounted on the entire surface so as to cover the surface on the side opposite to the original platen.

As shown in FIG. 1 and FIG.
Numeral 0 is attached not only to the surface of the carriage cover 212 on the original table side except for the reading window 28a, but also to the inside of the second housing portion 28. The adhesive tape 30 of the second storage unit 28 is attached to a surface of the wall forming the second storage unit 28 facing the document table 11. That is, the reading window 28 a and the reading slit 28 on the side of the carriage case 21 facing the platen 11.
An adhesive tape 30 is attached to portions other than the portion b.

Next, the operation of the above-described image reading apparatus 1 will be described. Original 2 that the user wants to read
Is placed on a document table 11 and instructed to start reading of the document 2 to the image reading device 1 via an application program for controlling the image reading device 1 such as, for example, TWAIN activated on the personal computer 3. I do.

When the user issues an instruction to start reading the original 2, the CPU 61 turns on the light source 22. And
The CPU 61 controls the driving unit 40 to move the carriage at a constant speed in the sub-scanning direction. Light reflected by the document 2 is incident on the line sensor 26, and the incident light is converted into electric charges and accumulated. The accumulated electric charge is applied to the line sensor 2 by a driving signal generated at predetermined time intervals.
6, and the electrical signals for one line are sequentially output to the processing unit 60. Processing unit 60
The digital image data corrected by the image processing circuit 64 is output to the personal computer 3 via the interface 16. The original 2 is read by repeating the above processing while moving the carriage 20 in the sub-scanning direction at a constant speed.

As described above, according to the image reading apparatus 1 of the above embodiment of the present invention, the carriage 20
An adhesive tape 30 as dust collecting means is disposed on the surface of the document table side. Therefore, when dust that has entered through the heat radiation holes 14 or the structural gap of the image reading device 1 and falls on the surface of the carriage 20 on the document table side, the dust is collected by the adhesive tape 30. Therefore,
It is possible to prevent dust from flying up as the carriage 20 moves and dust from entering the inside of the carriage 20. In addition, it is possible to prevent dust that has entered the inside of the carriage 20 from adhering to the mirror 23, and to reduce a decrease in image quality of a document to be read. Further, since the adhesive tape 30 used as the dust collecting means is inexpensive, the price of the image reading device 1 does not increase.

As described above, in the above embodiment of the present invention, an example in which an adhesive tape is applied as dust collecting means has been described.
The present invention is not limited to an adhesive tape, and an adhesive resin or an adhesive film can be used.

In the above embodiment, an image reading apparatus for reading a reflection original such as paper has been described. However, the present invention can be applied to an image reading apparatus for reading a transparent original such as a negative film or a positive film. is there.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an image reading apparatus according to an embodiment of the present invention.

FIG. 3 is a view of the carriage viewed from an arrow III direction in FIG. 1;

FIG. 4 is a cross-sectional view illustrating a conventional image reading apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image reading apparatus 10 Main body 11 Document table 20 Carriage 22 Light source 26 Line sensor (imaging means) 27 1st accommodation part 28 2nd accommodation part 30 Adhesive tape (dust collection means)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H04N 1/107 F term (Reference) 2H108 AA01 CA01 CB01 2H109 CA22 5C062 AA02 AA05 AB17 AD06 BA06 5C072 AA01 BA13 DA04 EA05 LA02 MA01 MA04 XA01

Claims (3)

[Claims] A document table on which a document can be placed; a light source for irradiating the document with light; an imaging unit for converting light reflected by the document into an electric signal; and a sub-scanning direction parallel to the document table. And a carriage that accommodates the light source and the imaging unit therein and has an opening that receives light from the document, and that is housed in the carriage and reflects light from the document. An image reading apparatus, comprising: one or more mirrors leading to the image pickup means; and dust collecting means disposed on a surface of the carriage on the document table side. 2. An image reading apparatus according to claim 1, wherein said dust collecting means is formed of an adhesive tape. 3. The image reading apparatus according to claim 1, wherein said dust collecting means is formed of an adhesive resin.