JPH11331496A - Image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize the appearance as much as possible by attaching plural mirrors to a casing by the form of supporting the back surfaces of the mirrors by the inner surface of the casing. SOLUTION: To the inner surface of a main case 11 in the casing 10, a first mirror M1, a second mirror M2, a third mirror M3 and a forth mirror M4 extended in a main scanning line direction are attached. The mirrors M1-M4 are held by the form of respectively fitting the back surfaces to recessed grooves 11A, 11B, 11C and 11D extended in a main scanning direction formed on the inner surface of the main case 11. Since the first mirror M1 - the forth mirror M4 are attached to the inner surface of the main case 11 in the casing 10 by the form of respectively supporting the back surfaces in such a manner, differently from a conventional image reader for which the end part of the mirror is passed through the side plate of a chassis and supported, the end parts of the respective mirrors M1-M4 are not projected from the casing 10. Thus, the appearance is miniaturized as much as possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source, which irradiates a document with light from a light source, reflects the light by a plurality of mirrors, guides the reflected light to an image forming lens, and forms an image on a image sensor. The present invention relates to an image reading apparatus configured to read image information on a document, and more particularly to a support structure for a plurality of mirrors.

[0002]

2. Description of the Related Art As one mode of an image reading apparatus mounted on a facsimile or a digital copying machine for reading image information on a document, a light source R, an imaging lens L, and a CCD image sensor S as shown in FIG. There is an image reading apparatus A including a first mirror M1, a second mirror M2, and a third mirror M3.

In this image reading apparatus A, a reflected light image obtained by irradiating a light from a light source R onto a document P first passes through an optical path indicated by an arrow a, and then a first mirror M1 and a second mirror M
2 and is incident on the third mirror M3. After being totally reflected by the third mirror M3, the second mirror M2 is again reflected.
The light is reflected by the first mirror M1, enters the image forming lens L, and is formed on the CCD image sensor S. The image signal is photoelectrically converted by the CCD image sensor S and read as image information.

According to the image reading apparatus A having the above configuration, the mirrors M1, M2 and M3 can be arranged close to each other while satisfying the required optical path length from the document P to the CCD image sensor S. Accordingly, the outer shape of the image reading device A can be reduced.

[0005]

As shown in FIG. 8, a light source R, an imaging lens L and a CCD image sensor S are mounted on a chassis B, and the first image reading apparatus A has a first mirror M1 and a second mirror M1. The second mirror M2 and the third mirror M3 are also assembled to the chassis B, respectively.

Here, a first mirror M1, a second mirror M2
And the third mirror M3, as shown in FIGS.
An end is penetrated through an opening Ca formed in the side plate C of the chassis B, and the end is pressed against an edge of the opening Ca by a leaf spring D screwed to the side plate Ca, thereby being attached to the chassis B. ing.

Thus, in the conventional image reading apparatus A,
On the side plate C of the chassis B, a plurality of mirrors M1,
Since the ends of M2 and M3 are penetrated and supported, the ends of the mirrors M1 to M3 protrude from the side plate C of the chassis B, and the width direction of the mirror in the image reading apparatus A (main scanning direction). Because of the large dimensions, it is difficult to reduce the size of the device, and there is a disadvantage that the appearance is inadvertently increased.

The present invention has been made in view of the above circumstances, and has as its object to provide an image reading apparatus capable of achieving the smallest possible appearance.

[0009]

In order to achieve the above object, an image reading apparatus according to the present invention includes a casing extending in a main scanning direction for a document, and a back surface of a mirror is supported on an inner surface of the casing. Thus, a plurality of mirrors are attached to the casing.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments. FIGS. 1 to 6 show an example in which the image reading apparatus according to the present invention is applied to an image reading apparatus mounted on a digital copying machine.

As shown in FIGS. 1 and 2, an image reading apparatus 1 according to the present invention comprises a casing 10 described later, a light source R, an imaging lens L, a CCD image sensor S, a first mirror M1, and a second mirror. M2, a third mirror M3, a fourth mirror M4 and the like are assembled.

Note that the image reading apparatus 1 in the embodiment is
The image information on the document P is read by moving in the sub-scanning direction with respect to the document P (see FIG. 2) set on the document table inside the housing of the digital copying machine (not shown). Device.

The casing 10 has a main case 11 extending in the main scanning direction with respect to the document P set on a document table (not shown). The main case 11 is made of aluminum. It is a long member made of an extruded material, and has a substantially concave cross section in which an upper portion and both ends are opened.

A side plate 12 is screwed to each end of the main case 11, and an upper cover 13 is screwed to the main case 10. The main case 10, the side plates 12, 12, and The upper cover 13 forms the casing 10.

As shown in FIG. 1, the casing 10 has lamp holders 20, 2 provided on side plates 12, 12, respectively.
The two light sources R, R are held via 0. The light sources R, R are small linear light sources composed of three-wavelength cold-cathode discharge tubes having emission wavelengths of red, green, and blue.

As shown in FIG. 2, the upper cover 13 is provided with a slit 13s for guiding the reflected light image from the document P to the inside of the casing 10. In order to prevent dust and the like from entering, a glass plate G is attached so as to cover the slit 13s.

As shown in FIG. 2, an imaging lens L is mounted on a main case 11 of the casing 10 via a lens mount 30 so that focus and magnification can be adjusted, and a CCD image sensor S is mounted. The circuit board 40 is mounted via the lens mount 30.

The CCD image sensor S is
A photoelectric conversion element array having sensitivity to each of red, green, and blue color lights is arranged in three rows at predetermined intervals, and is configured so that an image signal can be taken out independently for each color light.

Further, a CCD image sensor S is mounted on the circuit board 40, and a driving circuit for driving the image sensor S and an image signal output from the image sensor S are amplified, shaped, and shaped. A circuit for digital conversion is mounted, and a connector 41 for transmitting a digitized image signal from the image reading device 1 to a digital copying machine main body (not shown) is provided.

As shown in FIGS. 2 and 3, the casing 1
A first mirror M1, a second mirror M2, a third mirror M3, and a fourth mirror M4 extending in the main scanning line direction are attached to the inner surface of the main case 11 at 0.

These mirrors M1, M2, M3, M4 are:
The back surface is held in a concave groove 11A, 11B, 11C, 11D formed on the inner surface of the main case 11 and extending in the main scanning direction.

The first mirror M1 is connected to the main case 1
The left and right ends are pressed down from the front side by a pair of leaf springs 51, 51 (only one is shown in FIGS. 2 and 3) screwed to 1 and attached to the main case 11. .

Similarly, the second mirror M2 and the third mirror M3 are a pair of leaf springs 52, 52 screwed to the main case 11 (only one of them is shown in FIGS. 2 and 3).
The left and right ends of the fourth mirror M4 are pressed down from the front side by a pair of leaf springs 53, 53 (only one is shown in FIGS. 2 and 3) screwed to the main case 11. And is attached to the main case 11.

The main case 11 faces the left and right edges of each of the mirrors M1, M2, M3, M4 in order to regulate the longitudinal movement of each of the mirrors M1, M2, M3, M4. , Each groove 11A, 11B, 11C,
A stopper pin (not shown) is implanted in each of 11D.

Here, each of the mirrors M1 to M4 is a leaf spring 5
1 to 53, each groove 11A of the main case 11
11D, the displacement caused by the difference in the coefficient of thermal expansion between the main case 11 and each of the mirrors M1 to M4 is absorbed.

As shown in FIG. 4, the first mirror M1
Is arranged at an angle θ1 with respect to the optical axis H of the imaging lens L. Similarly, the second mirror M2 is arranged at an angle θ2, the third mirror M3 is arranged at an angle θ3, and the fourth mirror M4 is arranged at an angle θ4. ing. In this embodiment, θ1 is 40
°, θ2 is 72 °, θ3 is 8 °, and θ4 is 46.5.
° is set.

As shown in FIG. 5 as indicated by an optical path indicated by an arrow a, the irradiation light from the light sources R and R is reflected on the surface of the document P, and the reflected light image proceeds vertically downward and is totally reflected by the first mirror M1. , Are reflected by the second mirror M2 and the third mirror M3 and enter the fourth mirror M4.

Next, the light is totally reflected by the fourth mirror M4, and is again reflected by the third mirror M3, the second mirror M2, and the first mirror M.
After being reflected by 1 and entering the fourth mirror M4, the fourth mirror M4
The reflected light image reflected by the mirror M4 travels in the horizontal direction in the drawing, enters the imaging lens L, and is reduced and formed at a predetermined magnification on the photoelectric conversion element array of the CCD image sensor S.

The image signal photoelectrically converted and output by the CCD image sensor S is amplified, shaped and digitally converted by the circuit board 40, subjected to various kinds of image processing as required, and then passed through the connector 41. It is sent to the digital copier body (not shown).

Here, as shown in FIG. 6, the first mirror M
The first, second, third, and fourth mirrors M2, M3, and M4 are each set to have a minimum required size corresponding to the optical path (arrow a) of the reflected light image to the CCD image sensor S. The length of the mirror M1 is the longest, and then the length of the second mirror M2, the length of the third mirror M3, and the length of the fourth mirror M4 are reduced.

Further, as shown in FIG.
Each of the first, second, third, and fourth mirrors M2, M3, and M4 is formed to be shorter than the length of the main case 11 in the longitudinal direction, and is completely housed inside the casing 10.

In the image reading apparatus 1 configured as described above,
The first mirror M1, the second mirror M2, the third mirror M3, and the fourth mirror M4 are mounted on the inner surface of the main case 11 of the casing 10 in such a manner that the back surface is supported. Unlike the conventional image reading device that penetrates and supports the side plate, the ends of the mirrors M1 to M4 do not protrude from the casing 10, thereby achieving the smallest possible appearance. Becomes possible.

Further, in the conventional image reading apparatus, since the sharp mirror end protrudes from the side plate of the chassis, it is necessary to be careful in assembling the apparatus body into a pair, and the work efficiency is low. On the other hand, in the image reading device 1 according to the present invention, the mirrors M1 to M1
Since the end of the M4 does not protrude, it is easy to handle in assembling work and the like, and the work efficiency is improved.

Further, in the conventional image reading apparatus, an opening is provided in the side plate of the chassis so as to penetrate and support the end of the mirror. Light entering from this opening becomes stray light to improve reading accuracy. The image reading apparatus 1 according to the present invention has a disadvantage that the reading accuracy is impaired because the dust or the like that has been damaged or entered through the opening adheres to each of the mirrors M1 to M4, the imaging lens L, and the like. Since no opening is provided in the casing 10 for attaching a mirror, no light or dust enters the casing 10 carelessly.
Thus, it is possible to prevent the reading accuracy from being lowered.

Further, in the image reading apparatus 1 according to the present invention, the first mirror M1, the second mirror M2, the third mirror M3, and the fourth mirror M4 have minimum necessary dimensions corresponding to the optical path of the reflected light image. Since all the mirrors are longer than the chassis in order to penetrate and support the ends of the mirrors through the side plates of the chassis, a total of a plurality of mirrors are combined. The weight is reduced, and the image reading apparatus 1 configured to move in the sub-scanning direction as described above greatly contributes to a reduction in inertial weight.

In the above-described embodiment, the image reading apparatus which moves in the sub-scanning direction with respect to the fixed document is exemplified. Needless to say, the present invention can be effectively applied to an installed image reading apparatus.

The present invention is effectively applied not only to the image reading apparatus mounted on the digital copying machine shown in the embodiment but also to an image reading apparatus mounted on various devices such as a facsimile and an image scanner. Obviously you can get it.

[0038]

As described in detail above, the image reading apparatus according to the present invention includes a casing extending in the scanning direction for a document, and a plurality of sheets are provided in such a manner that the back surface of the mirror is supported on the inner surface of the casing. The mirror is configured to be attached to the casing. According to the above configuration, unlike the conventional image reading apparatus in which the end of the mirror penetrates the side plate of the chassis and is supported, the end of each mirror does not protrude from the casing, and thus the image related to the present invention is provided. According to the reading device, it is possible to achieve the smallest possible appearance.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing an image reading apparatus according to the present invention.

FIG. 2 is a sectional side view showing the image reading apparatus of the present invention.

FIG. 3 is an external perspective view of a main part showing a casing (main case) and a mirror of the image reading apparatus according to the present invention.

FIG. 4 is a conceptual diagram showing an arrangement of a plurality of mirrors in the image reading apparatus of the present invention.

FIG. 5 is a conceptual diagram showing an optical path in the image reading apparatus of the present invention.

FIG. 6 is a conceptual diagram showing mirrors and optical paths of the image reading apparatus according to the present invention.

FIG. 7 is a conceptual diagram showing a conventional image reading apparatus.

FIG. 8 is a conceptual diagram showing a conventional image reading apparatus.

FIG. 9 is a sectional side view showing a conventional image reading apparatus.

FIG. 10 is an external perspective view of a main part showing a conventional image reading apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Image reading apparatus, 10 ... Casing, 11 ... Main case, 12, 12 ... Side plate, 13 ... Upper cover, R ... Light source, M1 ... 1st mirror, M2 ... 2nd mirror, M3 ... 3rd mirror, M4 ... Fourth mirror, L: imaging lens, S: CCD image sensor, P: original.

Claims (2)

[Claims] An image information on a document is obtained by reflecting a reflected light image obtained by irradiating a document with light from a light source with a plurality of mirrors, guiding the reflected light image to an image forming lens, and forming an image on an image sensor. An image reading apparatus configured to read a plurality of mirrors, wherein the casing includes a casing extending in a main scanning direction with respect to the document, and the plurality of mirrors are attached to the casing so that an inner surface of the casing supports a back surface of the mirror. An image reading apparatus, comprising: 2. A method according to claim 1, wherein the length of the plurality of mirrors in the main scanning direction in each mirror is set to a minimum necessary size corresponding to an optical path from the light source to the image sensor. The image reading device according to claim 1.