JP3501544B2 - Contact image sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact-type image sensor for irradiating light emitted from a light source used in an image reading apparatus or the like and receiving reflected light from a document.

[0002]

2. Description of the Related Art Conventionally, an image reading device reads an image, a character, etc. written on a manuscript or the like and converts it into an image signal, and is used in a facsimile, an image sensor device, a copying machine and the like. Such an image reading apparatus has a main function of converting light reflected from a document or the like into an electric signal by a photoelectric conversion element, and a light source may be used to obtain the reflected light. As this photoelectric conversion element, there are CCD and MOS type sensors, a one-dimensional reading line sensor is used, and a contact type image sensor for directly reading the width of a document has been used recently.
In this case, as the light source, a plurality of LEs having the same width are used.
A D-chip, a thin linear fluorescent lamp, or the like is used, and a light source for one line is arranged in parallel with the line sensor to irradiate the original with light from the light source and to reflect the reflected light from the original. This image signal is supplied to an external device by receiving light by the line sensor, performing photoelectric conversion, and converting the pixel signal from each pixel of the line sensor into a time-series image signal. Then, for example, in the case of a facsimile, it is transmitted to an external facsimile apparatus via a transmission line, and the external facsimile apparatus converts the transmitted image signal into a monochrome printer signal and prints it out.

In an image reading apparatus equipped with a light source used together with the contact image sensor, as a method of positioning the image sensor and the light source, as shown in FIG. 6, a linear light source 1 such as a fluorescent lamp is provided at both ends. The socket 3 provided is provided with a light source mounting stupid hole D. FIG. 7 shows an external view of the frame 6 with the light source 2 attached.
It is fixed by screwing with the stupid hole D as an index. Further, FIG. 8 shows a partial sectional view of FIG. 7.

In FIG. 8, the light source 1 has a socket 3 fixed with a screw at a fool hole D, and when the light source 1 is turned on,
The original 7 is illuminated through the transparent glass plate 6 on the upper side. The light flux reflected from the original is transmitted through the glass plate 6 and focused by the lens array 5, and through the through hole provided in the frame 2, the photoelectric conversion element of the line sensor provided on the wiring board 8. It is projected to 4. 9 is frame 2
Is a chassis that covers the bottom of the lens, and 10 is a light shield plate that shields the light emitted from the light source 1 so that it does not directly enter the lens array 5. In this way, the image reading device converts the original image into an image signal by irradiating the original 7 sliding on the glass plate 6 with the photoelectric conversion element 4 of the image sensor to read the reflected light, and the photoelectric conversion element 4 is used. By reading the read one-dimensional image signal as the original 7 slides, the two-dimensional image signal can be output.

As a conventional example, there are various forms other than the above-mentioned optical path. For example, a contact type image sensor is arranged and fixed on the upper part of FIG.
There is also used a mode in which light from the above is radiated to the original through the transparent hole in the gap of the contact image sensor and the reflected light is read by the image sensor.

[0006]

However, as a method of positioning the image sensor and the light source in the above-mentioned conventional example, the processing position (pitch) accuracy of the mounting screw hole tap on the frame 2 and the socket portion 3 of the light source 1 are determined. Due to the accuracy of the processing position (pitch) of the mounting hole D, the mounting hole D of the socket portion 3 of the light source 1 needs to be loose relative to the diameter of the mounting screw. Therefore, the positioning accuracy of the frame 2 and the light source 1 is at least the light source 1 with respect to the diameter of the mounting screw.
The diameter of the mounting hole D for mounting the socket 3 becomes worse by the amount of looseness. For example, when M3 is used as the mounting screw, the mounting hole D of the socket 3 of the light source 1 needs to have a diameter of about 4 mm, and the positioning accuracy is ± 0.5 mm.

When the positioning accuracy of the light source 2 with respect to the frame 2 is poor, the effective irradiation distance of the light source 1 needs to be long by at least the backlash.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, to position the light source frame
The contact type image sensor attached to the frame
Position the socket of the light source against the end of the ram
A positioning surface for determining the position is provided.
Is the positioning in the X direction orthogonal to the longitudinal direction of the frame
Plane A, and the Y direction parallel to the longitudinal direction of the frame
Socket of the light source, which is composed of a surface B for positioning
The surface A and the surface B are provided on the frame.
By abutting the positioned surfaces A and B,
Positioning of the frame and the light source is performed .

The present invention further includes a front end portion of the frame.
A surface C on which the socket of the light source is placed is provided,
Make sure that the bottom surface C of the racket is brought into contact with the surface C of the frame.
Positioning of the frame and light source by
Is characterized by. Furthermore, attach the socket of the light source to the frame.
Fixed by pressing and fixing to the positioning surface A of the frame
A member is provided .

[0010]

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

FIG. 3 is an external view of the end portion of the frame 2 according to this embodiment. If the frame 2 is a contact type, it has a slender dimension in the Z direction, accommodates a light source, fixes an image sensor on the upper part of the frame 2 in the drawing, and places an original or the like having an image to be read on it and slides it. Move. Therefore, in terms of dimensions, it is important to position the light source and the image sensor, and the frame 2 serves as an intermediary. In this frame 2, an abutting surface A in the X direction and an abutting surface B in the Y direction are provided. An external view of the light source 1 housed in the frame 2 is shown in FIG. As shown in FIG. 4, the socket 3 of the light source 1 is provided with an abutting surface A in the X direction and an abutting surface B in the Y direction, and the surfaces A and B of the frame 2 and the socket 3 are in surface contact with each other. As in the above, they are positioned closely.

1 and 2 show an embodiment of assembly of the present invention. FIG. 1 is a perspective view of a contact image sensor in which a light source 1 such as a fluorescent lamp is positioned inside a frame 2. FIG. 2 is a side view showing the internal structure of the contact image sensor.

1 and 2, 1 is a light source for illuminating an original, 2 is a frame for holding each component, 3 is a socket portion for positioning the light source, 4 is a photoelectric conversion element, and 5 is an original image. An array of short-focus image forming elements for forming an image on the photoelectric conversion element, 6 is a cover glass, 7 is a document, A is an abutting surface in the X direction, and B is an abutting surface in the Y direction.

Further, FIG. 5 shows a state in which the light source 1 and the socket portion 3 are fixed to the frame 2. The frame 2 and the socket portion 3 are fixed by a pointed set screw 51 in the X direction of the A surface and the Z direction of the C surface, respectively on the front end and the rear end. The Y direction can be fixed at the same time by the pointed set screws 51 depending on the distance between the sockets 3 of the light source 1 and the setup of the frame 2.

In such a structure, the light source 1 has the frame 2
It is positioned and fixed to, but if the light source 1 is turned on,
The irradiation light emitted from the light source passes through the cover glass 6 and the original 7
Irradiate. The irradiation light produces reflected light according to a black-and-white or color image of the original 7, and the reflected light passes through the cover glass 6 and is transmitted by the short-focus imaging element array 5 to a CCD line sensor or M
An image is formed on the photoelectric conversion element 4 such as an OS type line sensor. The photoelectric conversion element 4 photoelectrically converts into an electric signal according to the amount of reflected light, converts the pixel signal of each pixel into an image signal of one line, and reads an image in accordance with sliding of the original 7,
It is output as a two-dimensional image signal. Thereafter, the image signal is subjected to image signal processing such as shading correction and binarization conversion by the image processing circuit in the wiring board 8 and output.

Reference numeral 9 denotes a chassis similar to the conventional example, which is provided with a light shielding plate or a light shielding film for directly shielding the light from the light source 2 to the short focus image forming element array 5, and the frame 2 has a short reflection light. An elongated light transmitting hole is provided for an optical path from the focus imaging element array 5 to the photoelectric conversion element 4. Also,
FIG. 3 is a single component view of the frame 2 as described above,
It shows an abutting surface A in the X direction and an abutting surface B in the Y direction.

FIG. 4 is a single component diagram of the light source 1 as described above, and shows the abutting surface A in the X direction and the abutting surface B in the Y direction of the socket portion 3. Then, the respective A-side and B-side comrades of the same figure are abutted against each other for positioning.

In the above embodiment, the example in which the photoelectric conversion element 4 is provided below the frame 2 has been shown. However, the arrangement of the light source and the arrangement of the photoelectric conversion element 4 are particularly effective for the irradiation light and reflected light of the light source. It is important to reach the photoelectric conversion element and how to accurately secure the effective irradiation distance of the light source. For this reason, the positioning is performed via the frame 2, and therefore the frame 2 and the light source 1 are arranged. Positioning is extremely important because it affects the distance of the optical path. In that case, the positioning means and the positioning fixing means shown in the present embodiment are particularly effective.

The arrangement of the light source, the frame, and the photoelectric conversion element is not limited to the above-mentioned embodiment, and the arrangement of the light source and the frame may be arranged according to the arrangement shown in the conventional example or other arrangements. The same effect can be obtained as long as it is fixed by abutting positioning.

Although an example of using a fluorescent lamp as a light source has been shown, even when an LED chip is used as a light source, when the chip fixing portion is fixed to the frame, a butting and positioning portion is provided for each and fixed. Of course, it may be fixed. In this case, since the LED itself has a narrow irradiation angle, the dimensions and accuracy of the abutting and positioning part are particularly required, but by using the present invention, the problems of the conventional example can be sufficiently solved and the irradiation becomes accurate, A higher quality image signal can be obtained.

[0021]

As described above, according to the present invention,
Positioning of the light source 1 with respect to the frame 2 becomes easy, and since the positioning is fixed by abutting, it is possible to reduce assembly cost and improve reliability.

Further, since the reliability of positioning is improved, it is not necessary to overspec the effective irradiation distance of the light source, the cost of the light source component is reduced, and the light source mounting space does not need to have a margin in the longitudinal direction. The contact image sensor unit can be made compact.

[Brief description of drawings]

FIG. 1 is a diagram in which a light source is positioned inside a frame according to an exemplary embodiment of the present invention.

FIG. 2 is a side view of an internal structure according to an embodiment of the present invention.

FIG. 3 is a single component diagram of a frame according to an embodiment of the present invention.

FIG. 4 is a single component diagram of a light source according to an embodiment of the present invention.

FIG. 5 is a conceptual diagram showing a fixing mode of a frame and a light source according to an embodiment of the present invention.

FIG. 6 is a single component diagram of a light source showing a conventional example.

FIG. 7 is an external view in which a light source is positioned inside a frame of an image reading apparatus according to a conventional example.

FIG. 8 is a sectional view of a frame portion of an image reading apparatus according to a conventional example.

[Explanation of symbols]

1 light source 2 frames 3 Light source socket 4 Photoelectric conversion element 5 Array of short-focus imaging element 6 cover glass 7 manuscript 8 wiring board AX direction abutting surface B Y direction abutting surface D Light source mounting hole

Claims (3)

(57) [Claims] 1. A contact image sensor for positioning a light source and mounting it on a frame, wherein an end portion of the frame is provided.
To position the light source socket by butting it against
Positioning surface is provided, and the positioning surface is
Surface A for positioning in the X direction orthogonal to the longitudinal direction of the frame,
And positioning in the Y direction parallel to the longitudinal direction of the frame
The surface B of the light source, and the surface of the socket portion of the light source.
Positioning A and surface B respectively provided on the frame
By abutting the facing surfaces A and B, the frame
A contact-type image sensor characterized by positioning a light source and a light source . 2. The socket of the light source is attached to an end of the frame.
Is provided with a surface C on which the socket portion is placed, and the bottom surface of the socket portion.
By abutting C on the face C of the frame,
A contract characterized by positioning the frame and the light source.
Contact image sensor according to Motomeko 1. 3. The light source socket portion on the frame
To fix the frame by pressing it against the positioning surface A of the frame.
The constant member is provided, The claim 1, 2 characterized by the above-mentioned.
The contact type image sensor described in.