JPH10190910A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dust from flowing into a housing part accompanying cooling air, to prevent the contamination of an optical means and to miniaturize a blowing means by arranging a photoelectric conversion means and a cooling means on the outside of the housing part. SOLUTION: A first mirror base 10, a second mirror base 11 and a condensing lens 12 are arranged inside a frame body 1. On the outside of the frame body 1, a CCD unit 16 and a cooling fan 17 which is the blowing means, etc., are arranged. The dust-proof member of sponge or the like is held between metal sheets, where a CCD sensor which is the photoelectric conversion means is fixed and the sticking of the dust to the light-receiving surface side of the CCD sensor is prevented. Thus, the cooling air from the fan 17 efficiently cools the CCD sensor and heat generation components on a sensor board, the dust included in the cooling air does not reach the mirror bases 10 and 11, and the condensing lens 12 and good images are obtained at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device.

[0002]

2. Description of the Related Art In recent years, digital copying machines in which an electrophotographic copying machine is regarded as an image input / output device of a computer and image input and image output are digitized have become widespread. The image input unit of this digital copying machine converts the image information into an electric signal by using a photoelectric conversion element such as a CCD sensor to read the image and sends it to the image output unit. Therefore, the interface between the image input unit and the image output unit is connected to a signal line. It is possible to put them both in completely different frames and to place them in different places. Therefore, in the digital copying machine, the image input unit is independent of the image output unit, and the contamination of the image input unit due to the scattering of the developer in the image output unit, which is a problem in the conventional analog copying machine, can be reduced.

As a light source for an image input section of such a digital copying machine, a halogen lamp is often used because of its rising speed and a large amount of light. However, a halogen lamp generates a lot of heat, and it is necessary to send cooling air from the outside into the image input unit to cool it. Further, in order to prevent dust from entering the image input unit, an electrostatic filter must be provided at the cooling air intake.

[0004] As a light source replacing the halogen lamp, a fluorescent lamp is currently receiving attention. Fluorescent lamps not only generate less heat than halogen lamps, but also increase the amount of light in recent years, and can be sufficiently used for image reading units of high-speed copying machines and color copying machines. In addition, it becomes possible to eliminate the means for cooling the light source, which is necessary when a conventional halogen lamp is used.

[0005]

However, the temperature rise due to heat generation of a CCD sensor and a sensor driving circuit (hereinafter, referred to as a CCD unit) used for obtaining an image signal is as follows.
When the CCD is driven at a high speed, it is still a technical problem that cannot be overcome. Therefore, a cooling fan is required to cool the CCD unit.

Further, in an analog copying machine, an original image is read in units of slits, whereas in a digital copying machine, C is read.
Since an original image is read by one line (several microns in width) of the CD sensor, even a small amount of dust on the image reading optics adversely affects the output image. Further, since the image input unit and the image output unit can be easily separated, for example, only the image input unit may be placed in a dusty environment,
It is necessary to provide dustproof means such as an electrostatic filter at an intake port of a cooling fan or the like of the CCD unit, which has led to an increase in cost of the image reading apparatus.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and comprises a document table on which a document is placed, and photoelectric conversion means for reading an image on the document and outputting an image signal. An optical unit that guides an image on the document to the photoelectric conversion unit, a storage unit of a dustproof structure that stores the optical unit, and a cooling unit that cools the photoelectric conversion unit,
The photoelectric conversion unit and the cooling unit are arranged outside the storage unit.

[0008]

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

(First Embodiment) FIG. 1 shows an image reading section of a digital copying machine embodying the present invention. In FIG. 1, reference numeral 1 denotes a frame, and 2 denotes a platen glass as a document table. The platen glass 2 is fixed to the frame body 1, and an elastic body such as rubber or sponge (not shown) is sandwiched in a gap between the two to form a storage unit having a dustproof structure.
The frame 1 itself is formed by assembling a sheet metal or the like into a substantially box shape and fixed by welding, screwing, or the like. Alternatively, in order to increase the airtightness of the frame itself so that external dirt, dust, and the like do not enter the frame as much as possible, the frame may be formed of an aluminum die-cast or plastic molding.

Inside the frame 1, a first mirror base 10, a second mirror base 11, and a condenser lens 12 are arranged. The first mirror base 10, the second mirror base 11, and the condenser lens 12 constitute optical means. Outside the frame 1, a CCD unit 16, a cooling fan 17 as a blower, and the like are arranged. The first mirror base 10 includes a first mirror base 20, a light source 21 including a fluorescent lamp, a reflection mirror 22,
23, 24 and a first mirror 25. Also, 2
Reference numerals 6 and 27 denote sliders for the first mirror base 10 to slide on the optical rail 30.

The second mirror base 11 is provided on the second mirror base 4.
0, a second mirror 41, and a third mirror 42, and the second mirror 41 and the third mirror 42 are arranged such that the normals of their reflection surfaces are orthogonal to each other. 45 and 46 are the second
The mirror base 11 is a slider for slidingly traveling on the optical rail 30. The condenser lens unit 12 includes a plurality of lens groups and is disposed inside the frame 1.

Next, a detailed view of the CCD unit 16 and the cooling fan 17 arranged outside the frame 1 is shown in FIG. A dustproof member such as sponges 55 and 56 is sandwiched between a first sheet metal 51 directly fixed to the frame 1 and a second sheet metal 52 to which a CCD sensor 54 serving as a photoelectric conversion unit is fixed. The dust is prevented from adhering to the light receiving surface side 57 of 54. The first sheet metal 51 and the second sheet metal 52 are CC
After determining the optical position of the D sensor 54, the D sensor 54 is connected by the solders 63 and 64.

The CCD sensor 54 is connected to a sensor board 58 which is a processing means for performing primary processing of a signal output from the CCD sensor 54. Sensor board 5
Behind 8, there is provided a duct 61 which is an introduction means for guiding wind from a cooling fan 60 fixed to the frame 1.

Next, the operation of the image reading apparatus will be described. The light 68 emitted from the light source 21 of the first mirror base 10 shown in FIG. 1 is reflected and condensed by the reflection mirrors 22, 23, and 24 and irradiates the original. The illuminated image on the document is reflected by the first mirror 25, is turned back by the second mirror 41 and the third mirror 42 on the second mirror base 11, and is incident on the condenser lens 12. Image on top.

As described above, the light source 21, the respective mirrors, and the condenser lens 12 are arranged in the space surrounded by the platen glass 2 and the frame 1, and the CCD sensor 5 which is a heat-generating component.
4. The sensor board 58 is arranged outside the frame 1. As a result, the temperature inside the image input unit is greatly increased due to heat generation, and a portion that requires cooling and a portion that hardly raises temperature and dislikes dust can be spatially separated.

When the CCD sensor 54 is driven at a high speed, C
The specific components on the CD sensor 54 and the sensor board 25 generate heat, and unless these are appropriately cooled, the original image cannot be accurately converted into an image signal. Therefore, in the present image reading apparatus, as shown in FIG. 2, the duct outlets 82 and 83 for guiding the air from the cooling fan are arranged around the heat-generating component 80 on the CCD sensor 54 and the sensor board 58 so that the cooling can be performed efficiently. It is supposed to do.

In this way, the cooling air from the fan 17 can efficiently cool the heat-generating components 80 on the CCD sensor 54 and the sensor board 58, and the dust contained in the cooling air will A good image can always be obtained, irrespective of the lens.

(Second Embodiment) FIG. 3 shows an image reading apparatus according to a second embodiment of the present invention. In FIG. 3, the condenser lens 12, the CCD unit 16 and the like are connected to a CCD base 100.
The CCD lens unit 101 is disposed on the upper side and constitutes the CCD lens unit 101.

The CCD lens unit 101 is suspended from the frame 1 at three points by a simple mechanism 110 using springs and screws.
Tilt adjustment can be performed. If the condenser lens 12 and the CCD unit 16 are unitized as described above, CC
The mechanism required for adjusting the positions of the D lens unit 101 and the D lens unit 101 before assembling them into the main body can be reduced in size.

Also in this embodiment, as in the first embodiment, the CCD unit 1 which generates a large amount of heat and needs to be cooled.
6 and each mirror part which does not generate much heat and dislikes dust can be spatially separated. Then, a discharge port of a duct for guiding wind from a cooling fan is arranged around a specific heat-generating component on the CCD sensor and the sensor board, so that cooling is performed efficiently.

In the present embodiment, the condenser lens 12 is located outside the frame (that is, not located in the space of each mirror), but the condenser lens forms the third space by the cover 120. This space can also be separated from the space in which the CCD unit 16 is arranged, so that the condenser lens 12 can be prevented from being exposed to dust generated by the cooling air of the CCD unit 16.

[0022]

As described above, according to the present invention, a document table on which a document is placed, photoelectric conversion means for reading an image on the document and outputting an image signal, and photoelectric conversion means for converting the image on the document to the photoelectric conversion means Optical means, a storage part of a dustproof structure storing the optical means, and a blowing means for cooling the photoelectric conversion means, wherein the photoelectric conversion means and the blowing means are arranged outside the storage part. .

And, by having such a configuration,
It is possible to prevent dust from flowing into the storage unit due to the cooling air, and prevent contamination of the optical unit. Further, the size of the air blowing means can be reduced, thereby reducing the power consumption and vibration of the entire apparatus, preventing noise, and performing high-quality image reading. Further, it is not necessary to use expensive dustproof means such as an electrostatic filter, so that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an image reading apparatus according to an embodiment.

FIG. 2 is a configuration diagram of an image reading apparatus according to an embodiment.

FIG. 3 is a configuration diagram of an image reading apparatus according to the embodiment.

[Description of Signs] 1 Frame 2 Platen Glass 10 First Mirror Stand 11 Second Mirror Stand 12 Condensing Lens 17 Cooling Fan 21 Light Source 54 CCD Sensor 58 Sensor Board 61 Duct

Claims (7)

[Claims] 1. A document table on which a document is placed, a photoelectric conversion unit that reads an image on the document and outputs an image signal, an optical unit that guides the image on the document to the photoelectric conversion unit, and the optical unit An image reading apparatus, comprising: a storage unit having a dustproof structure storing therein, and a blowing unit for cooling the photoelectric conversion unit, wherein the photoelectric conversion unit and the blowing unit are arranged outside the storage unit. 2. The image reading apparatus according to claim 1, wherein processing means for performing predetermined processing on the image signal is arranged outside the storage section. 3. An image reading apparatus according to claim 1, wherein said optical means comprises a reflection mirror and a lens. 4. The image reading apparatus according to claim 3, wherein the storage section includes a first storage section storing the reflection mirror and a second storage section storing the lens. 5. The image reading apparatus according to claim 1, wherein a light source for irradiating the original is further disposed inside the storage section. 6. The image reading apparatus according to claim 1, further comprising an introduction unit for guiding the wind blown from the blowing unit to the photoelectric conversion unit. 7. The image reading apparatus according to claim 2, further comprising an introduction unit for guiding wind blown from the blowing unit to the photoelectric conversion unit and the processing unit.