JPH0784323A - Document image forming device - Google Patents

Abstract

PURPOSE:To provide a document image forming device of low noise with a large blast quantity in spite of being compact and small in storage space so as to uniformly cool the inside of the case of a scanning means including a contact glass. CONSTITUTION:A document 1 placed on a contact glass plate 2 is scanned by a document scanning means 3 and read by a reading means while being illuminated by a lighting means 7. A document image forming device of such constitution has a scanning means 3 for scanning the placed document 1 by moving in the auxiliary scanning direction from the lower side of the contact glass plate 2, and plural axial fans 4 different in the rotating directions of propellers 5. Plural axial fans 4 are disposed in parallel in the main scanning direction of the scanning means 3, in an outside air sucking position from the home position side of the scanning means 3, and air is sent from plural axial fans 4 disposed in parallel. Cooling is thereby performed in such a way as to uniform the temperature in the case 6 of the scanning means 3 including the contact glass plate 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document image forming apparatus, and more particularly to an improvement of a document image forming apparatus having a structure for cooling a scanning means located in a casing including a contact glass such as a copying machine and an image scanner. .

[0002]

2. Description of the Related Art Generally, in a copying machine of an original image forming apparatus, especially in a digital color copying machine, a halogen lamp having a high color temperature is used as an illuminating means of the original,
As the scanner method, the field sequential scanning method is adopted,
Since one copy is made for every four scans, the halogen lamp having a high color temperature as a means for illuminating an original document has an extremely long lighting time, and the contact glass or the like tends to have an abnormally high temperature and become high in temperature. Further, in the digital color copying machine, in addition to the illumination means, parts including a lamp power source, a DC power source, a heating element such as a memory, etc. are built in the scanner casing. The necessity of lowering the temperature by cooling the inside of the housing is increasing.

Therefore, various cooling devices have been proposed for preventing the temperature rise of the contact glass or the like in a copying machine or the like. Although neither method is sufficient, it is generally attempted to prevent temperature rise by installing a cross fan for blowing air and blowing the blowing air toward the contact glass (Japanese Patent Publication No. 60
-27006, especially FIG. 2, JP-A-61-1
See, for example, Japanese Patent No. 179429, FIG. 4). On the other hand, while there is a demand like this, there is also a demand for noise reduction during driving as represented by BAM (Blue Angel Mark). Therefore, these demands have an antinomy factor, and as a result, they are extremely contradictory. As a measure for preventing a high temperature rise, it is difficult to adopt a method of simply adding a fan to improve cooling efficiency. As described above, copying machines and the like are expected to be downsized and to reduce noise, but a cooling device for preventing a temperature rise has a large storage space and generates a lot of noise. It was not easy to achieve.

[0004]

In the above-mentioned conventional document image forming apparatus, the cooling device for preventing the temperature rise in the housing of the scanning means including the contact glass is
There was a problem that the storage space was large and the noise was loud.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention is to solve such a problem. That is, an object of the present invention is to provide a document image forming apparatus that is small in size, has a large air flow rate even if the storage space is small, and has a low noise, and that uniformly cools the inside of the housing of the scanning unit including the contact glass. And

[0006]

In order to achieve the above-mentioned object, the present invention is to scan a document placed on a contact glass with a document scanning unit while illuminating it with a lighting unit to scan a document image with a reading unit. In a document image forming apparatus for reading a document, a scanning unit for moving a placed document from below the contact glass in the sub-scanning direction to scan the document and a plurality of axial fans having different propeller rotation directions are provided. The axial fans are arranged in parallel in the main scanning direction of the scanning means at a position where the outside air is sucked in from the home position side of the scanning means, and air is blown from a plurality of axial fans arranged in parallel, The document image forming apparatus is most characterized in that the original image forming apparatus cools the inside of the housing including the contact glass of the scanning means to be uniform. The main feature is that a plurality of axial fans are arranged substantially symmetrically with respect to the central axis of the frame of the housing along the sub-scanning direction. The main feature is that the air conditioning plate is provided in front of the axial fan near the optical axis of the reading means.

[0007]

In the original image forming apparatus constructed as described above, the casing including the contact glass sucks the outside air from the home position side of the scanning means by the plural axial fans arranged in parallel with the propellers rotating in different directions. Original image formation that evenly cools the inside of the housing of the scanning means including the contact glass by a device that is small in size, has a large amount of air to be blown even if the storage space is small, and is low noise by uniformly blowing the air inside the body to cool. To be able to provide the device.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a vertical sectional view showing a schematic configuration of an example of an image forming apparatus to which the present invention is applied, and FIG. 2 is a plan view thereof. In FIGS. 1 and 2, an electrophotographic copying which is an example of an original image forming apparatus. The machine has a contact glass 2 on which an original 1 is placed on an upper surface of a housing 6, and a scanning unit 3, an axial fan 4, and an illuminating unit are provided in a space defined by the housing 6 and the contact glass 2. 7, a reading means 8, a wind regulating plate 9 and the like are arranged. The original 1 placed on the contact glass 2 is illuminated from below the contact glass 2 by an illumination means 7 such as a halogen lamp having a high color temperature, and the original reflected light is imaged on the CCD 8c via the scanning means 3. It That is, the drive pulley 10 driven by a drive source (not shown)
And the wire that is wound around the other pulley 10a and travels, and the first carriage 3b and the second carriage 3e
Moves in the sub-scanning direction. The reflected light of the document is transmitted by the first mirror 3 mounted on the first carriage 3b and the second carriage 3e.
a, reflected by the second mirror 3c, and the third mirror 3d, and imaged on the CCD 8c by the imaging lens 8b of the reading means 8. As a result, the document image is scanned and read to form the document image. It has become.

On the back side of the scanning means 3, that is, the first carriage 3b and the second carriage 3e which move in the sub-scanning direction, an illumination power source 11, a DC power source 12, as a heat source,
The motor driver 13 and the like are stored. The amount of heat generated by these heat sources is smaller than that of the illumination means 7. In other words, the amount of heat generated from the illumination means 7 is large and is located directly below the contact glass 2, so that the contact glass 2 is overheated, causing a safety problem.
Therefore, in the present embodiment, the axial flow fan intensively blows air in the vicinity of the illumination means 7 and the contact glass to forcibly cool it.

That is, in this embodiment, the two axial fans 4a and 4b are arranged at the same height position on the wall surface on the left side of the drawing, that is, the wall surface on the home position side before the reading of the operation means 3, and the respective axes are arranged. Propeller 5 that constitutes the flow fans 4a and 4b
A characteristic is that a and 5b are formed in a shape having twists in opposite directions. In other words, one propeller 5a (forward rotation direction propeller) introduces outside air into the equipment by rotating in the forward direction indicated by arrow A, and the other propeller 5b (reverse rotation direction propeller) moves in the opposite direction indicated by arrow B. It is configured to introduce outside air into the equipment by rotating. As shown in FIG. 2, the axial fans 4a and 4b are arranged substantially symmetrically with respect to the central axis 6a of the frame of the housing 6 along the sub-scanning direction of the scanning means 3. Further, the axial fan 4a on the front side, which is the side where the illumination means 7 is located, has the reading means 8
Is arranged on the optical axis 8a.

Further, as shown in FIGS. 1 and 2, an air rectifying plate 9 is erected from a floor surface directly below the axial fan 4a to a lower portion of the fan 4a so as to prevent outside air introduced from the axial fan 4a. By this air conditioning plate 9, the upper side, that is, the contact 2
It is designed to be guided to the side and the front side (Fig. 4).
That is, the air conditioning plate 9 is arranged so as to be inclined so that the outside air introduced by the axial fan 4a is guided to the front side. According to the experiment by the present inventor, this outside air is adjusted to the outside air conditioning plate 9.
It has been found that the action of the positively moves it upward. Although the theoretical elucidation of the cause of such a phenomenon has not been made yet, it has been confirmed by experimental data that there is some applied relationship between the configuration and the result. In this embodiment, the air conditioning plate 9 is provided between the axial fan 4a and the third mirror 3d so that the air is circulated to the front side near the lead edge 2a.

FIG. 3 is an enlarged view of an essential part of FIG. 1. In FIG. 3, the air conditioning plate 9 extends upward from the bottom surface 6b of the housing 6 and reaches the vicinity of the propeller 5a in the forward rotation direction of the axial fan 4a. The propeller 5a in the forward rotation direction extends to the position shown in FIG.
Since it is configured to rotate outward in the direction, a part of the air blow in the lower part of the axial fan 4a is sent to the front.

FIG. 4 is a plan view showing a blown state. Since the blown air flows of the plurality of axial fans 4a and 4b are blown in the directions of arrows C1 to C4, the contact glass 2 is blown. Illuminating means 7 such as a halogen lamp having a high color temperature (not shown) flowing along the inner wall surface of the housing 6 including
Other than the above, the illumination power source 11, the DC power source 12, the motor driver 13 and the like stored on the back side can also be cooled. Since the heat source on the back side has less adverse effect on the contact glass as compared with the illumination lamp 7, the air conditioning plate is unnecessary.

FIGS. 5 (a), 5 (b) and 5 (c) and FIGS. 6 (d) and 6 (c) show the rotation of the propellers 5a and 5b of the axial flow fans 4a and 4b in the original image forming apparatus of the above-described embodiment. The direction and the effect of the air rectifying plate 9 are shown by comparing the strength and direction of the blown air. The strength of the air blown on the lower surface of the contact glass 2 is shown by the length of the straight line arrow in the figure, and the direction is shown by the direction of the straight line arrow. Further, each of the above propeller shapes is configured so that outside air can be introduced into the device when rotated in the direction of the arrow, and the figure shows the lower surface of the contact glass when each propeller is rotated in the outside air introduction direction. It shows the blast strength along with it.

That is, the embodiment shown in FIG. 5A is the axial fan 4
a and 4b propellers of the same shape, respectively, propellers 5b and 5b
And the case where the propellers 5b and 5b are rotated in the same direction is shown. The embodiment shown in FIG. 5 (b) is a propeller 5 of the same shape.
The case where the axial fans 4a and 4b having a and 5a rotate in the same direction is shown. When the propellers 5a and 5b having different shapes rotate in different directions from each other in the embodiment of FIG. 5 (c) and the embodiment of FIG. 6 (d), the embodiment of FIG. 6 (e) implements the embodiment of FIG. 6 (d). This is an example in which a wind regulating plate 9 is added to the example. When rotating in the same direction as in the embodiment of FIGS. 5 (a) and 5 (b),
There is a place with negative pressure, which is a problem. In the embodiment of FIG. 5 (c) and the embodiment of FIG. 6 (d), the strength of the air flow is more uniform than that of the embodiment of FIG. 5 (a) and the embodiment of FIG. 5 (b). Figure 6
In the embodiment of (e), since the air conditioning plate 9 is added, the strength of the blown air flows uniformly. That is, in FIG. 6 (d), the air on the side of the axial flow fan 4a is non-uniform, but it is made uniform by the action of the air conditioning plate 9 and is in an ideal state.

[0016]

Since the present invention is constructed as described above, contact air is drawn in from the home position side of the scanning means by a plurality of parallel-arranged axial fans having different propeller rotation directions. Since it is designed to uniformly blow air into the casing including the air conditioner, even if the size is small and the storage space is small, the amount of air blown is large and the inside of the casing of the scanning means including the contact glass is cooled evenly in a low noise device. It is now possible to provide a document image forming apparatus that does.

[Brief description of drawings]

FIG. 1 is a front vertical sectional view showing a main part of a document image forming apparatus showing an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is an explanatory view of a side cross-section in which a part of a main part of a document image forming apparatus showing an embodiment of the present invention is enlarged.

FIG. 4 is an explanatory diagram illustrating a blown state of the document image forming apparatus according to the embodiment of the present invention.

5 (a), (b), and (c) are explanatory diagrams of graphs comparing the effects of the original image forming apparatuses of the embodiments of the present invention.

6 (d) and 6 (e) are explanatory diagrams of graphs comparing the effects of the original image forming apparatuses according to the embodiments of the present invention.

[Explanation of symbols]

1 ... manuscript, 2 ... contact glass, 2a ...
Lead edge (LE), 3 ... Scanning means, 3a ...
1st mirror, 3b ... 1st carriage, 3c ... 2nd mirror, 3d ... 3rd mirror, 3e ... 2nd carriage, 4 ... Axial fan, 4a ... Axial flow Fan (close to the optical axis), 4b ... axial fan, 5 ... propeller, 5a ... forward rotation direction propeller, 5b ... reverse rotation direction propeller, 6 ... housing, 6a ...・ Center axis of frame, 6b ... bottom surface, 7 ... illuminating means, 8 ...
Reading means, 8a ... Optical axis, 8b ... Imaging lens, 8
c ... CCD, 9 ... Air conditioning plate, 10 ... Driving pulley, 11 ... Lighting power supply, 12 ... DC power supply, 13
... Motor driver.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 1/04 101 7251-5C

Claims (3)

[Claims] 1. A document image forming apparatus in which a document placed on a contact glass is scanned by a document scanning unit while being illuminated by an illumination unit directly below the contact glass and a document image is read by a reading unit. Further, it has a scanning means for moving the original document from below the contact glass in the sub-scanning direction to scan it, and a plurality of axial fan with different propeller rotation directions. -By arranging them in parallel along the main scanning direction of the scanning means at a position where the outside air is sucked in from the mu-position side, and by blowing air from a plurality of axial fans arranged in parallel,
An original image forming apparatus, characterized in that cooling is performed so that a temperature of a casing of the scanning means including the contact glass is uniform. 2. The original image forming method according to claim 1, wherein the plurality of axial fans are arranged substantially symmetrically with respect to the central axis of the frame of the casing along the sub-scanning direction. apparatus. 3. The original image forming apparatus according to claim 1, wherein an air conditioning plate is provided in front of the axial fan nearer to the optical axis of the reading means.