JP3005112B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital copying machine having a reduction optical system using a CCD line sensor as a reading element.
The present invention relates to an image reading device such as an image scanner and a facsimile.

[0002]

2. Description of the Related Art In recent years, with digital copiers and the like, as the processing speed has been increased, the reading speed of a reading unit has been increased.
Pixel clocks in CD line sensors also tend to be faster. As a result, the amount of heat generated by the CCD line sensor increases, the dark current increases, the S / N ratio decreases, and the image is adversely affected. That is, according to a data book or the like regarding a CCD linear image sensor, for example, FIG.
Since the dark-time output characteristic as shown in (1) and (2) above indicates that an increase in the ambient temperature increases the dark-time output, the S / N decreases as the temperature rises.

Therefore, in this type of image reading apparatus, a scanner cooling fan 1 is provided as shown in FIG.
By introducing outside air into the machine, the IPU plate 2, VPU
The vicinity of the CCD line sensor 4 is cooled together with the circuit board such as the plate 3. In FIG. 1, reference numeral 5 denotes an image forming lens for forming a light image reflected from a document on the contact glass 6 through the mirror optical system 7 and forming the image on the CCD line sensor 4.

[0004]

However, a general method using the cooling fan 1 is not preferable because it causes a noise problem in recent environmental problems. Since the use of the cooling fan 1 means that outside air is taken into the device, a dust filter for preventing the mirror optical system 7 and the like from being contaminated and an ozone filter for exhaust from the device to the outside are required. , Resulting in high costs.

On the other hand, when only the heat radiation of the CCD line sensor is considered, it is considered that a heat radiation plate may be attached to the surface of the CCD line sensor by bonding or screw fixing. But,
If the heat sink is fixed in this manner, a force (load) acts in a direction in which the surface of the CCD line sensor is peeled off, which is not preferable. In addition, if the coefficient of thermal expansion between the radiator plate and the CCD line sensor is different, the CCD line sensor may be distorted or cracked when thermally expanded, which is not preferable from this aspect.

[0006]

A reading substrate formed by soldering a CCD line sensor onto a printed circuit board is provided on a bracket, and an imaging lens for the CCD line sensor is mounted on the reading substrate to position the CCD line sensor with respect to the bracket. An image provided with an adjustable lens block, and a reduced reading optical system in which the bracket and the lens block are relatively displaced so that the optical axis of the imaging lens is aligned with the reading line of the CCD line sensor. In the reading device according to the first aspect of the present invention, a fixed portion fixed to the bracket, a displacement portion guided by a window formed in the bracket and movable in an optical axis direction, and a cover glass surface on a surface of the CCD line sensor. An elastic member having a high thermal conductivity having a pressing portion in contact with the light-transmitting portion corresponding to the reading line is provided.

According to the present invention, the CC can be moved in the optical axis direction by being guided by a window formed in the bracket.
A rigid member having high thermal conductivity having a pressing portion in contact with the cover glass surface of the D line sensor surface and a light transmitting portion corresponding to the reading line is provided, and one end is fixed to the bracket, and the rigid member is connected to the CCD line. A leaf spring member having high thermal conductivity and pressed against the sensor was provided.

According to the third aspect of the present invention, the CCD can be moved in the optical axis direction by being guided by a plurality of shaft members for maintaining a distance and a position between the bracket and the reading substrate.
A heat conductive and rigid heat radiating plate having a pressing portion in contact with the cover glass surface of the line sensor surface and a light transmitting portion corresponding to the reading line is provided, and one end is fixed to the bracket, and the heat radiating plate is connected to the CCD. A spring member for pressing the line sensor is provided.

[0009]

The radiation of the CCD line sensor is performed through an elastic member, a rigid member, or a heat radiating plate having high thermal conductivity pressed against the cover glass surface on the surface of the CCD line sensor. A cooling means for taking in is unnecessary, and problems such as noise and high cost are eliminated.
Further, since these elastic members and the like are only in pressure contact with each other and are not fixed to the CCD line sensor by bonding or the like, there is no problem of giving stress, distortion, cracking and the like.

[0010]

An embodiment of the present invention will be described with reference to FIG. FIG. 1 shows the vicinity of an imaging lens 11 and a CCD line sensor 12 in a reduced reading optical system of a scanner as shown in FIG. The imaging lens 1
Reference numeral 1 is mounted and held on a lens block 13 whose front and rear lenses are open. On the other hand, the CCD line sensor 12 is soldered on a printed board 14 to form a reading board 15. A cover glass 16 is provided on the surface of the CCD line sensor 12. Furthermore, this CC
The D-line sensor 12 is formed in a substantially U-shape when viewed from the side, and is fixedly supported by a screw or the like (not shown) on the back side of the bracket 17.

The bracket 17 is for adjusting the optical axis of the imaging lens 11 so as to coincide with the reading line of the CCD line sensor 12.
Is inserted into the bracket 17, and an adjustment displacement mechanism is provided between the bracket 17 and the lens block 13. That is, a compression spring 18 is provided on one side between the bracket 17 and the lens block 13,
On the other side, a pair of a wedge screw 19 and a ball 20 is provided, and by moving the wedge screw 19 back and forth, the optical axis can be finely adjusted.

Here, a window 17a is formed in a part of the bracket 17 near the optical axis and through which light condensed by the imaging lens 11 is formed. An elastic member 21 is formed near the window 17a. Is provided. The elastic member 21 is made of a leaf spring having a high thermal conductivity.
a displacement portion 21a which is guided in the optical axis direction and is movable in the optical axis direction, a pressing portion 21b which comes into contact with the surface of the cover glass 16, and a light transmitting portion formed in the pressing portion 21b corresponding to the reading line of the CCD line sensor 12. And both ends are fixed to the inner surface of the bracket 17 as fixing portions 21d.

According to such a configuration, the CCD line sensor 12 is radiated by the bracket 17 via the cover glass 16 and the pressing member 21 having high thermal conductivity. Therefore, a cooling fan for taking in cooling air into the scanner is not required, and heat radiation of the CCD line sensor 12 can be secured. Therefore, the problem of noise is eliminated, and a dustproof filter and an ozone filter are not required, so that the cost can be reduced. Further, the pressing portion 21b is moved to the CCD line sensor 1 by the spring property of the pressing member 21 itself.
(Cover glass 16) Since it is only in pressure contact with the surface and is not fixed with adhesive or screws, CC
There is no stress on the D-line sensor 12 and no distortion or cracking.

Next, an embodiment of the present invention will be described with reference to FIG. The same parts as the parts shown in the above-mentioned embodiment are denoted by the same reference numerals (the same applies to the following embodiments). In this embodiment, it can be said that the elastic member 21 is substantially divided into two members. First, the pressing portion 22b guided by the window 17a and movable in the optical axis direction and in contact with the surface of the cover glass 16 and the pressing portion 22b A rigid member 22 having high heat conductivity and having a substantially U-shape having a light transmitting portion 22c formed corresponding to the reading line of the CCD line sensor 12 is provided in 22b. On both sides of the rigid member 22, one end is fixed to the bracket 17, and a leaf spring member 23 having high thermal conductivity for pressing the rigid member 22 toward the CCD line sensor 12 is provided.

According to such a configuration, the CCD line sensor 12 is mounted on the bracket 17 via the cover glass 16, the rigid member 22 having high heat conductivity and the leaf spring member 23.
Will be dissipated. Therefore, an effect similar to that of the above embodiment can be obtained. In particular, according to the present embodiment,
Since it is composed of two parts, the rigid member 22 and the leaf spring member 23,
Unlike the elastic member 21 of the above-described embodiment, it is not necessary to form a complicated shape for giving the elastic force to itself.

An embodiment of the present invention will be described with reference to FIG. In this embodiment, first, a plurality of shaft members 24 for maintaining the distance and the positional relationship between the bracket 17 and the reading board 15 (printed board 14) are illustrated and fixed with screws 25. Thus, a heat radiating plate 26 having an opening 26a for these shaft members 24 and guided movably in the optical axis direction is provided. The heat radiating plate 26 has high thermal conductivity and high rigidity, and is formed so as to correspond to the pressing portion 26b in contact with the surface of the cover glass 16 and the reading line of the CCD line sensor 12 in the pressing portion 26b. And a light transmitting portion 26c. On both sides of the heat radiating plate 26, one end is fixed to the bracket 17, and a spring member 27 for pressing the heat radiating plate 26 toward the CCD line sensor 12 is provided. The spring member 27 is an example of a leaf spring, but may be a coil spring or the like.

According to such a configuration, the CCD line sensor 12 includes the cover glass 16 and the heat-radiating plate 2 having high thermal conductivity.
6 dissipates heat. Therefore, an effect similar to that of the above embodiment can be obtained. In particular, according to this embodiment, since the heat radiation plate 26 is used, no special thermal conductivity is required on the spring member 27 side, and the degree of freedom of the material and the structure is increased.

[0018]

Since the present invention is constructed as described above, the heat of the CCD line sensor is dissipated by an elastic member having high thermal conductivity brought into pressure contact with the cover glass surface of the CCD line sensor, or by heat. It is performed through a highly conductive rigid member and a leaf spring member, or a heat conductive and rigid heat radiating plate, so that cooling means such as a cooling fan for taking in outside air for heat radiation of the CCD line sensor becomes unnecessary. Noise and high cost can be solved, and these elastic members are only in pressure contact with each other, and are not fixed to the CCD line sensor by bonding or the like.
Problems such as applying stress to the CCD line sensor, distorting the CCD line sensor, and generating cracks do not occur.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of the invention described in claim 1;

FIG. 2 is a partially cutaway side view showing one embodiment of the invention described in claim 2;

FIG. 3 is a partially cutaway plan view showing one embodiment of the invention described in claim 3;

FIG. 4 is a temperature characteristic diagram of a dark output voltage of a general CCD.

FIG. 5 is a schematic configuration diagram of a scanner showing a conventional example provided with a cooling fan.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Imaging lens 12 CCD line sensor 13 Lens block 14 Printed board 15 Reading board 16 Cover glass 17 Bracket 17a Window 21 Elastic member 21a Displacement part 21b Press part 21c Light transmission part 21d Fixed part 22 Rigid member 22b Pressure part 22c Light transmission part 23 Leaf spring member 24 Shaft member 26 Heat radiating plate 26b Pressing portion 26c Light transmitting portion 27 Spring member

Claims (3)

(57) [Claims] 1. A reading board formed by soldering a CCD line sensor onto a printed board is provided on a bracket, and an image forming lens for the CCD line sensor is mounted on the reading board. The lens is adjustable in position with respect to the bracket. A block, and relatively displacing the bracket and the lens block to move the optical axis of the imaging lens to the CCD.
In an image reading apparatus provided with a reduced reading optical system adapted to a reading line of a line sensor, a displacing portion movable in an optical axis direction guided by a fixing portion fixed to the bracket and a window formed in the bracket. And the CC
An image reading apparatus, comprising: an elastic member having a high thermal conductivity having a pressing portion in contact with a cover glass surface on a surface of a D line sensor and a light transmitting portion corresponding to the reading line. 2. A lens which is provided with a reading board formed by soldering a CCD line sensor on a printed board and held on a bracket, mounts an image forming lens for the CCD line sensor, and is adjustable in position with respect to the bracket. A block, and relatively displacing the bracket and the lens block to move the optical axis of the imaging lens to the CCD.
In an image reading apparatus having a reduced reading optical system adapted to a reading line of a line sensor, the image reading apparatus is movable in the optical axis direction by being guided by a window formed in the bracket, and is in contact with a cover glass surface of the CCD line sensor. A highly heat-conductive rigid member having a pressing portion and a light-transmitting portion corresponding to the reading line is provided, and one end is fixed to the bracket to press the rigid member toward the CCD line sensor. An image reading apparatus comprising a leaf spring member. 3. A lens which is provided with a reading board formed by soldering a CCD line sensor on a printed board and held on a bracket, and which is provided with an imaging lens for the CCD line sensor and whose position can be adjusted with respect to the bracket. A block, and relatively displacing the bracket and the lens block to move the optical axis of the imaging lens to the CCD.
In an image reading apparatus having a reduced reading optical system adapted to a reading line of a line sensor, light is guided by a plurality of shaft members for maintaining a distance and a position between the bracket and the reading substrate. A heat conductive and rigid heat radiating plate having a pressing portion movable in the axial direction and in contact with the cover glass surface of the CCD line sensor surface and a light transmitting portion corresponding to the reading line is provided, and one end is fixed to the bracket. An image reading apparatus further comprising a spring member for pressing the heat radiating plate toward the CCD line sensor.