JP2000253209A - Picture reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To read picture of high quality without blurring and shifting of the picture at high speed by providing a bearing holding part fixing a bearing connected so that it can move in the scanning direction, a mirror holding part fixing a mirror and a reinforcing plate reinforcing the bearing holding part and the mirror holding part, in a second carriage. SOLUTION: Since a reinforcing plate 20 reinforces the bearing holding part 18 and the mirror holding part 19 of a second carriage, the strength of single bodies on the bearing holding part 18 of the second carriage and the mirror holding part 19 of the second carriage and the fitting strength of the mirror holding part 19 of the second carriage to the bearing holding part 18 of the second carriage are sufficiently reinforced. Thus, the change of an angle between the center line of the bearing 14 and the mirrors 7 and 8 and that between the mirrors 7 and 8 are reduced at the movement of the second carriage 6, the length of an optical path from a reading start position to a reading end position becomes constant and the picture of good reading precision is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image reading apparatus for reading an image described in an original, a magazine, or the like.

[0002]

2. Description of the Related Art In an image reading apparatus in which a manuscript, a magazine, and the like are placed on a manuscript glass and an image is read from the manuscript and the magazine,
Conventionally, a device provided with a first carriage for holding one mirror and a second carriage for holding two mirrors has been widely used.

FIG. 7 is a schematic view showing a main part of a conventional image reading apparatus.

In FIG. 7, 1 is a document glass on which a document is placed, 2 is a first carriage, and 3 and 4 are first carriages 2.
5 is a mirror mounted on the first carriage 2, 6 is a second carriage, 7 and 8 are mirrors mounted on the second carriage 6, 9 is a lens for focusing light, and 10 is a lens 9. An optical coupling element (hereinafter, abbreviated as a CCD) that receives the light passing through and converts the intensity of the light into an electric signal, and 11 is an optical path from the original to the CCD. Note that 2-A and 6-A indicate the reading start positions of the first carriage 2 and the second carriage 6, and 2-B and 6-B indicate the reading end positions of the first carriage 2 and the second carriage 6.

FIG. 8 is a perspective view of the second carriage 6 as viewed obliquely from above, FIG. 9 is a plan view of the second carriage 6, and FIG. 10 is a sectional view of a mirror holding portion of the second carriage 6.

8 and 9, reference numeral 12 denotes a bearing holding portion of the second carriage 6, 13 denotes a mirror holding portion of the second carriage 6, and 14 denotes fixed to both ends of the bearing holding portion 12 of the second carriage in the longitudinal direction. The bearing 15 is a shaft guide fixed to the mirror holding portion 13 of the second carriage 16.
Is a main shaft that passes through the bearing 14 and slides with the bearing 14, 17 is a sub-shaft that supports a shaft guide 15, and the second carriage 6 is supported by the main shaft 16 and the sub-shaft 17, and has a reading start position and a reading start position. Slide between end positions. Here, the mirror holding unit 13 of the second carriage is different from the bearing holding unit 12 of the second carriage in FIG.
13-a, 13-b and 13-c.

[0007] The operation of the conventional image reading apparatus thus configured is as follows.

An original is placed on an original glass 1 and illuminated by lamps 3 and 4. The light reflected from the original is reflected at 90 ° at the mirror 5 and further reflected at 90 ° at the mirror 7.
And reflected by the mirror 8 at 90 °. After that, the light is
And then enters the CCD 10. For one line of reading, the elements of the CCD 10 provided with 400 to 600 pixels per inch convert the intensity of light proportional to the density of the original into the magnitude of an electric signal. In this way, the image is read line by line of the document. In order to perform the reading operation line by line from the leading end to the trailing end of the document, the first carriage 2 moves from the reading start position to the reading end position, and at the same time, the second carriage 6 is moved to half of the first carriage 2. To move at the speed of.

Here, in order to read a high-quality image without fluctuation of the read image and image displacement, the first carriage 2 is required.
When the second carriage 6 moves, the optical path length is constant from the reading start position to the reading end position, and the image is always read at the set position 2-a of the first carriage. For this purpose, the angle between the center line of the bearing of the second carriage 6 and the mirror shown in FIG. 9 and the angle between the mirrors 7 and 8 shown in FIG.
It is necessary that the bearing holding portion 12 of the second carriage and the mirror holding portion 13 of the second carriage do not vibrate.

[0010]

However, in the above-described conventional configuration, when the bearing holding portion 12 of the second carriage 6 and the mirror holding portion 13 of the second carriage 6 are made of resin,
In addition to these weaknesses, the mounting strength of the mirror holding portion 13 of the second carriage to the bearing holding portion 12 of the second carriage is also weak. Therefore, when the second carriage 6 moves,
The angle between the center line of the bearing 14 and the mirrors 7, 8 and the angle between these mirrors 7, 8 tend to change from 90 °. Also,
The bearing holding part 12 of the second carriage and the mirror holding part 13 of the second carriage vibrate, and as a result,
There has been a problem that the read image fluctuates and the image is shifted.

On the other hand, when the bearing holding portion 12 of the second carriage and the mirror holding portion 13 of the second carriage are made of metal such as aluminum, the second carriage 6
The weight of the carriage becomes heavy, and it cannot cope with an increase in the moving speed of the carriage.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image reading apparatus capable of reading a high-quality image at high speed without image fluctuation and image shift.

[0013]

According to the present invention, there is provided a first carriage having one mirror for receiving light from a scanning surface, and an optical path to an optical coupling element which receives light from the mirror of the first carriage. An image reading apparatus comprising: a second carriage having two mirrors to be formed; wherein the first carriage and the second carriage can be driven in a scanning direction, wherein the second carriage is movable in the scanning direction. A bearing holding portion of a second carriage for fixing a bearing connected to the mirror, a mirror holding portion of a second carriage for fixing the mirror, and both a bearing holding portion of the second carriage and a mirror holding portion of the second carriage Characterized in that it is provided with a reinforcing sheet metal for reinforcing the above.

With this configuration, it is possible to read a high-quality image at high speed without fluctuation or displacement of the image.

[0015]

According to the first aspect of the present invention, a first carriage having one mirror for receiving light from a scanning surface, and a light from the mirror of the first carriage to an optical coupling element. Second with two mirrors forming the optical path of
An image reading apparatus comprising a carriage, wherein the first carriage and the second carriage are drivable in a scanning direction, wherein the second carriage fixes a bearing connected to the scanning carriage so as to be movable in the scanning direction. A bearing holding portion of the carriage,
An image reading apparatus, comprising: a mirror holding portion of a second carriage for fixing the mirror; and a reinforcing sheet metal for reinforcing both the bearing holding portion and the mirror holding portion of the second carriage. As a result, the strength of the bearing holding portion of the second carriage and the mirror holding portion of the second carriage and the strength of attaching the mirror holding portion of the second carriage to the bearing holding portion of the second carriage are increased. The angle between the bearing center line and the mirror and the angle between the two mirrors of the second carriage can be kept within a range of 90 ° ± several minutes, and the bearing holding portion of the second carriage and the mirror holding portion of the second carriage Has the effect of suppressing the vibration of

According to a second aspect of the present invention, the angle between the mirror of the mirror holding portion and the center line of the bearing is set to 90 °, and the reinforcing sheet metal is screwed to the bearing holding portion and the mirror holding portion. 2. The image reading apparatus according to claim 1, wherein a diameter of a fixing hole of the reinforcing sheet metal to the bearing holding portion is larger than an outer diameter of the screw. Thus, the angle between the mirror of the mirror holding portion and the center line of the bearing can be reliably set to 90 °.

According to a third aspect of the present invention, there is provided the image reading apparatus according to the first or second aspect, wherein a reinforcing sheet metal is attached with reference to a back surface of the mirror holding portion. Can be easily set to 90 °, and the screw can be screwed to a position that is effective for improving the strength of the mirror holding portion.

Hereinafter, embodiments of the present invention will be described.

FIG. 1 is a perspective view of a second carriage of an image reading apparatus according to an embodiment of the present invention as viewed obliquely from above, FIG. 2 is an exploded perspective view of the second carriage as viewed from below, and FIG. Is an exploded perspective view showing a state before the reinforcing sheet metal of the second carriage is mounted by combining the bearing holding part of the second carriage and the holding part of the second carriage, and FIG. 4 shows a state where the second carriage is mounted on a jig. It is a perspective view. Note that the same components as those in the related art are denoted by the same reference numerals, and description thereof is omitted.

1 to 4, reference numeral 18 denotes a bearing 1 at both ends.
4, a bearing holding portion of the second carriage 6 having two mirrors 7 and 8, and a bearing holding portion 18 of the second carriage 6 having two mirrors 7 and 8. It is a reinforcing sheet metal for reinforcing both of the mirror holding portions 19.

The reinforcing sheet metal 20 is provided with holes 20-a and 20-b corresponding to the positioning pins 19-a and 19-b of the mirror holding portion 19 of the second carriage. When the portion 18 and the mirror holding portion 19 of the second carriage are combined, they have a planar shape in which they are restricted and arranged in an L-shape. Auxiliary sheet metal 20
The procedure for attaching the second carriage to the bearing holder 18 and the second carriage to the mirror holder 19 is as follows.

First, the positioning pins 18-a and 18-b of the bearing holding portion 18 of the second carriage and the holes 19-c and 19-d of the mirror holding portion 19 of the second carriage are fitted and positioned. As shown in FIG. 3, the bearing holding section 18 of the second carriage and the mirror holding section 19 of the second carriage are combined. In this state, the positioning pins 19-a and 19-b of the mirror holding portion 19 of the second carriage and the holes 20-a and 20-b of the reinforcing metal plate 20 are fitted and positioned to hold the mirror of the second carriage. Screws 21 are screwed into bosses 19-e to 19i provided on the portion 19, and then bosses 18-c and 18-c provided on the bearing holding portion 18 of the second carriage.
Screw the screw 22 into d. In addition, screw holes 20-c are formed in the reinforcing sheet metal 20 at positions corresponding to the bosses 19-e to 19-i, 18-c, and 18-d, and screws 21 and
22, the reinforcing sheet metal 20 is fixed to the mirror holding portion 19 of the second carriage and the bearing holding portion 18 of the second carriage.

Next, the shaft 24 provided on the jig 24
The bearings 14 fixed to both ends of the bearing holding portion 18 of the second carriage in the longitudinal direction are inserted into -a, and the shaft guide 15 fixed to the mirror holding portion 19 of the second carriage is connected to the projection 24 of the jig 24. -B
The jig 24 is set with the second carriage 6 in which the bearing holding portion 18 of the second carriage, the mirror holding portion 19 of the second carriage, and the reinforcing sheet metal 20 are combined. At this time, the shaft 24-a and the bearing 1 of the bearing holding portion 18 of the second carriage are used.
Since the diameters of the two are set so that there is almost no gap between them, the center line of the shaft 24-a substantially coincides with the center line of the bearing 14. Next, as shown in FIG.
The angle between the center line of the bearing 14 and the mirror of the mirror holding portion 19 of the second carriage is set to 90 ° by using an autocollimator 25 which is an angle measuring device installed on the upper surface 4. In this setting method, the mirror holding unit 19 of the second carriage is
While rotating in the direction of arrow A or arrow B at
The adjustment is performed so that the straight line L of FIG. 5 displayed on the display window 25-a is within several scales. In the display of FIG. 5, the straight line L is aligned with the -2.5 scale, and the mirror angle is (9
0 ° -2.5 minutes). At this time, since the bearing holding portion 18 of the second carriage is made of resin, the L-shaped corner thereof is slightly deformed when a force is applied.
Even if it is fixed to the reinforcing sheet metal 20 by the
The rotation of the mirror holding portion 19 of the carriage in the A or B direction is possible. In the state set within 90 ° ± several minutes as described above, the screw 23 is inserted into the screw hole 20- of the reinforcing sheet metal 20.
c and screwed into each of the bosses 18-e to 18-j and tightened. Here, the angle between the center line of the bearing 14 and the mirrors 7 and 8 of the mirror holding portion 19 of the second carriage is set to 90 degrees.
° so that the screw holes 20-c of the reinforcing sheet metal 20 can be adjusted.
Is larger than the outer diameter of the screws 22 and 23. Also, the second
By mounting the reinforcing sheet metal 20 with reference to the back surface of the mirror holding portion 19 of the carriage, the angle between the bearing center line and the mirror can be easily set to 90 °, which is effective for improving the strength of the mirror holding portion 19 of the second carriage. Screws can be tightened in certain places.

In the above construction, both the bearing holding portion 18 of the second carriage and the mirror holding portion 19 of the second carriage can be reinforced by the reinforcing sheet metal 20 to increase the strength of each. Even if the bearing holding part 18 and the mirror holding part 19 of the second carriage are made of a member made of synthetic resin, sufficient strength can be provided. Therefore, the entire carriage is significantly reduced in weight as compared with a case where the bearing holding portion 18 of the second carriage and the second carriage 6 are made of metal such as aluminum in order to increase the strength.

When reading an image, the first carriage 2
The second carriage 6 moves at half the speed of. FIG. 6 is a configuration diagram of a drive system of the image reading device according to the embodiment of the present invention. 6, the first carriage 2 and the second carriage 6 are driven by a first carriage driving gear 26, a second carriage driving gear 27, and a first carriage driving gear 26 to reciprocate the first carriage 2 as a driving mechanism. A first carriage driving belt 28 and a second carriage driving belt 29 rotated by the second carriage driving gear 27 to reciprocate the second carriage 6 are provided. The first carriage drive belt 28 is fixed to the first carriage 2 at a portion indicated by 2-b in the figure, and the second carriage drive belt 29 is fixed to the second carriage 6 at a portion indicated by 6-b. Here, by setting the pitch diameter of the second carriage driving gear 27 to half the pitch diameter of the first carriage driving gear 26, the second carriage 6
Travel at half the speed of.

Since the bearing holding portion 18 of the second carriage 6 and the mirror holding portion 19 of the second carriage are reinforced by the reinforcing sheet metal 20, the bearing holding portion 18 of the second carriage and the mirror of the second carriage 6 are reinforced. The strength of the holding unit 19 alone and the second strength of the mirror holding unit 19 of the second carriage
The mounting strength of the carriage to the bearing holding portion 18 is sufficiently enhanced. Therefore, when the second carriage 6 moves, the angle between the center line of the bearing 14 and the mirrors 7, 8 and the angle change between the mirrors 7, 8 can be kept within 90 ° ± several minutes, and the second Vibration of the bearing holding portion 18 of the carriage and the mirror holding portion 19 of the second carriage is prevented. Therefore, the optical path length is constant from the reading start position to the reading end position, and a high-quality image with good reading accuracy can be obtained. In addition, since the second carriage 6 is made of resin to reduce the weight, the carriage can be moved at a high speed.

[0027]

According to the present invention, there is provided a reinforcing sheet metal for reinforcing both the bearing holding portion of the second carriage and the mirror holding portion of the second carriage, and the angle between the mirror of the mirror holding portion of the second carriage and the bearing center line is provided. When the second carriage is moved, the reinforcing sheet metal is fixed to the bearing holding portion of the second carriage and the mirror holding portion of the second carriage in a state where is set to 90 °. The angle between the two mirrors of the mirror holding part of the two carriages is 90 °
Can be controlled within a few minutes. Further, since vibration of the bearing holding portion of the second carriage and the mirror holding portion of the second carriage is prevented, a high-quality image with good reading accuracy can be obtained. Further, by using the reinforcing sheet metal, the bearing holding portion of the second carriage and the mirror holding portion of the second carriage can be made of resin, so that the weight of the carriage can be reduced and the speed of the carriage movement can be increased.

[Brief description of the drawings]

FIG. 1 is a perspective view of a second carriage of an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is an exploded view of a second carriage of the image reading apparatus according to the embodiment of the present invention.

FIG. 3 is an exploded view of a second carriage of the image reading apparatus according to the embodiment of the present invention.

FIG. 4 is a perspective view showing a state where the second carriage is attached to a jig.

FIG. 5 is a diagram showing a scale display of an autocollimator.

FIG. 6 is a configuration diagram of a drive system of the image reading apparatus according to the embodiment of the present invention.

FIG. 7 is a schematic diagram showing a main part of a conventional image reading apparatus.

FIG. 8 is a perspective view of a second carriage of the conventional image reading apparatus.

FIG. 9 is a plan view of a mirror holding unit of a second carriage of the conventional image reading apparatus.

FIG. 10 is a sectional view of a mirror holding portion of a second carriage of the conventional image reading apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Original glass 2 First carriage 3, 4 Lamp 5 Mirror 6 Second carriage 7, 8 Mirror 9 Lens 10 CCD (optical coupling element) 11 Optical path 12 Bearing holding part of second carriage 13 Mirror holding part of second carriage 14 Bearing REFERENCE SIGNS LIST 15 shaft guide 16 main shaft 17 sub shaft 18 bearing holding portion of second carriage 19 mirror holding portion of second carriage 20 reinforcing sheet metal 21, 22, 23 screw 24 jig 25 autocollimator 26 first carriage drive gear 27 second carriage Drive gear 28 First carriage drive belt 29 Second carriage drive belt

Claims (3)

[Claims] 1. A first carriage having one mirror for receiving light from a scanning surface, and two mirrors for receiving light from a mirror of the first carriage and forming an optical path to an optical coupling element. An image reading apparatus comprising: a second carriage, wherein the first carriage and the second carriage can be driven in a scanning direction, wherein the second carriage fixes a bearing connected to be movable in the scanning direction. An image reading apparatus comprising: a bearing holding unit; a mirror holding unit that fixes the mirror; and a reinforcing sheet metal that reinforces both the bearing holding unit and the mirror holding unit. 2. An angle between a mirror of the mirror holding portion and a center line of the bearing is set to 90 °, and the reinforcing sheet metal is connected to the bearing holding portion and the mirror holding portion via a screw,
2. The image reading apparatus according to claim 1, wherein a diameter of a fixing hole of the reinforcing sheet metal to the bearing holding portion is larger than an outer diameter of the screw. 3. The image reading device according to claim 1, wherein the reinforcing sheet metal is attached with reference to a back surface of the mirror holding portion.