JPH0556217A - Reduction optical mechanism for image scanner - Google Patents

Abstract

PURPOSE:To change an optical path with the movement of a lens, to obtain two kinds of reduction optical magnification, to cope with the size of the width of an original and to always obtain a large number of picture elements. CONSTITUTION:This mechanism is provided with a fluorescent lamp tube 1, a first mirror 5 reflecting reflected light from an original 2, a second mirror 6, a lens 8 integrally supported by a third mirror 7 and a line sensor 9. Two mirrors 11 and 12 are newly provided on the upper and lower parts of a carriage 10 so that another optical path different from the optical path obtained at the time of no movement of the lens 8 can be obtained when the lens 8 integrally supported by the third mirror 7 is moved along a feeding screw 13 by the driving force of a motor 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reduction optical mechanism of an image scanner capable of changing an optical path length.

[0002]

2. Description of the Related Art FIG. 3 is a cross-sectional view schematically showing an optical path and a layout relationship of respective parts in a reduction optical mechanism of a conventional image scanner.

In the figure, 1 is a fluorescent tube as a light source, 2
Is a manuscript (or photo or printed matter) with letters or pictures, 3
Is a cover for pressing the original 2 and preventing transmission of light emitted from the fluorescent tube 1, 4 is a transparent glass plate for placing the original 2, and 5 is an original illuminated by the fluorescent tube 1. A first mirror for reflecting the reflected light reflected by the two surfaces at a right angle, 6 a second mirror for reflecting the reflected light from the first mirror 5 at a right angle, and 7 a second mirror This is a third mirror for reflecting the reflected light from the mirror 6 at a right angle.

Further, 8 is a lens for forming an image of the reflected light from the third mirror 7 as information of the original 2, and 9 is an image formed by the lens 8 for converting the image into an electric signal. The line sensor 10 includes the fluorescent tube 1, the first mirror 5, the second mirror 6, the third mirror 7, and the lens 8.
And a carriage for holding the line sensor 9 and configuring the whole as one system.

Next, the operation of the above configuration will be described. Now, as shown in FIG. 3, the light emitted from the fluorescent tube 1 is reflected by the surface of the original 2 and advances through the slit opening 10a in the upper part of the carriage 10 in the direction of the arrow along the alternate long and short dash line to form the first mirror 5 Reflect at a right angle and proceed to the left.
Subsequently, this reflected light is reflected at a right angle by the second mirror 6 and travels downward, and is reflected at a right angle again by the third mirror 7 and enters the right lens 8 side.

The reflected light incident on the lens 8 is imaged as information of the original 2 and further enters a line sensor 9 on the right side, where the information of the original 2 is converted into an electric signal.

In this way, the entire reduction optical mechanism held by the carriage 10 moves in the direction of the arrow A in the figure, and the information of the original 2 is sequentially read by the line sensor 9, whereby the length of the original 2 is increased. The reading of one sheet of information according to is completed.

[0008]

The reduction optical mechanism of the conventional image scanner is constructed as described above, and since the lens 8 is fixed at a fixed position, the information from the document 2 is large or small depending on the size of the document. However, since the image is formed by the line sensor 9 at a constant magnification, the density of the read information of one line is constant as long as it is read at the same magnification.

If one line of short information is magnified and read twice by processing on an electric circuit, the density of the information will be reduced to 1/2, and a dense document such as a picture or a photograph will be read. In some cases, there was the inconvenience that the roughness was noticeable in the details.

The present invention has been made to solve the above problems, and provides a reduction optical mechanism of an image scanner capable of accurately reading in detail even minute information of a document such as a picture, a photograph, and a character. It is an object.

[0011]

In order to achieve the above object, in the present invention, a light source, a first mirror for reflecting the reflected light which is emitted from the light source and reflected on the original surface, and the first mirror are provided. Second mirror for reflecting the reflected light from the second mirror, a third mirror for reflecting the reflected light from the second mirror, and a lens for forming an image of the reflected light from the third mirror In a reduction optical mechanism of an image scanner equipped with a line sensor for converting this image formation into an electric signal in a carriage, in particular, the third mirror is fixed to the carriage without fixing the third mirror to the carriage. The lens and the lens are supported so as to be movable integrally, and driving means for moving the third mirror and the lens in the left-right direction is provided. When the third mirror and the lens are moved, the second mirror is moved. From A mirror for reflecting the reflected light, but on the top and bottom of the new carriage two mirrors of the mirror for reflecting the third mirror reflects the light reflected from the mirror.

[0012]

According to the present invention, the optical path when the third mirror and the lens integrally supported with the third mirror are not moved, the reflected light emitted from the light source and reflected on the original surface is the first mirror. , The second mirror, the third mirror, the lens, and the line sensor, and the optical paths when the third mirror and the lens are moved by the driving means are the first mirror and the second mirror. The order of the optical paths is the mirror, the bottom mirror of the carriage, the top mirror of the carriage, the third mirror, the lens, and the line sensor. Even in this case, it is possible to always reflect the reflected light traveling downward from the vertical direction to the center of the lens. Therefore, it is possible to select two types of reduction optical optical paths according to the document size, and it is possible to obtain high pixels corresponding to the width of the document.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing the configuration of a reduction optical mechanism of an image scanner according to the present invention. The same or corresponding parts as in FIG. 3 showing a conventional example are designated by the same reference numerals and detailed description thereof will be omitted. ..

As shown in FIG. 1, the third mirror 7 is not fixed to the carriage 10 as in the conventional example,
The lens 8 is integrally supported by the lens 8 and the connecting member 8b, and the lens 8 is moved left and right on a feed screw 13 rotatably supported on the bottom of the carriage 10 via an arm 8a attached to the lower portion of the lens 8. It is supported so that it can be moved to.

Reference numeral 14 denotes a motor which is a drive source, and the driving force generated by the motor 14 is transmitted to the end portion of the feed screw 13 to cause the feed screw 13 to move.
Is configured to be rotatable.

Numerals 11 and 12 are mirrors for reflecting the reflected light and changing the optical path length, which are arranged on the upper and lower portions of the carriage 10.

Next, the operation of the above configuration will be described. First, a normal reading state will be described with reference to FIG. In this case, the reading method is the same as the conventional reading method. Now, the light emitted by the fluorescent tube 1 which is the light source is
The slit opening 1 of the carriage 10 is reflected by the surface of the original 2
0a travels in the direction of the arrow following the alternate long and short dash line, is reflected at a right angle by the first mirror 5, and travels to the left. Next, this reflected light is reflected at a right angle by the second mirror 6, travels downward, is reflected at a right angle by the third mirror 7, and the lens 8 on the right side is reflected.
Incident on.

The reflected light incident on the lens 8 enters the image forming surface of the line sensor 9 arranged on the right side of the carriage 10, and the information of the original 2 is converted into an electric signal.

In this way, the entire reduction optical mechanism composed of the functional parts held by the carriage 10 moves in the direction of arrow A in the figure, so that the line sensor 9 sequentially reads the information of the document 2. Reading of one document is completed.

Next, the operation for changing the optical path length will be described. First, when the motor 14 is driven by driving the motor 14, the feed screw 13 rotates, and by the rotation of the feed screw 13, the arm 8a movably supported on the feed screw 13 moves to the right. .. Therefore, the lens 8 supported by the arm 8a and the third mirror 7 supported by the connecting member 8b also move to the right along with the movement of the lens 8 and the third mirror 7.
Moves from the state shown in FIG. 1 to the state shown in FIG.

As described above, when the lens 8 and the third mirror 7 move rightward in the carriage 10, the reflected light reflected at a right angle by the second mirror 6 is reflected by the third mirror 7 in FIG. As a result of moving to the right from the state shown in FIG. 2, it is reflected by the mirror 11 and the reflected light advances toward the mirror 12. Then, the reflected light reflected by the mirror 12 travels toward the third mirror 7 that has moved to the right, and is reflected at a right angle by the third mirror 7. Further, the reflected light reflected by the third mirror 7 enters the lens 8. The following optical paths enter the line sensor 9 as before the movement shown in FIG.

As illustrated in the above embodiment, according to the present invention, the optical path can be changed by the movement of the lens in the carriage, and two types of reduction optical magnifications can be easily obtained. Corresponding to, a high pixel count can always be obtained.

[0023]

As described above, according to the present invention, by moving the lens in the carriage, it is possible to select two types of reduction optical optical paths according to the size of the original, and the width of the original is large. There is an effect that a high pixel corresponding to the height can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration of a reduction optical mechanism of an image scanner according to the present invention.

2 is a cross-sectional view showing a state where a lens and a mirror in FIG. 1 are moved.

FIG. 3 is a cross-sectional view schematically showing an optical path and an arrangement relationship of respective parts in a reduction optical mechanism of a conventional image scanner.

[Explanation of symbols]

 1 Fluorescent Tube 5 First Mirror 6 Second Mirror 7 Third Mirror 8 Lens 9 Line Sensor 10 Carriage 11, 12 Mirror 13 Feed Screw 14 Motor

Claims (1)

[Claims] 1. A light source, a first mirror for reflecting the reflected light emitted from the light source and reflected on the original surface, a second mirror for reflecting the reflected light from the first mirror, and A third mirror that reflects the reflected light from the second mirror, a lens for forming an image of the reflected light from the third mirror, and a line sensor for converting the formed image into an electric signal are provided. In a reduction optical mechanism of an image scanner provided in a carriage, a driving means for integrally supporting the third mirror and the lens and moving the third mirror and the lens in the left and right direction, A mirror for reflecting the reflected light from the second mirror when the third mirror and the lens move, and a mirror for reflecting the reflected light from this mirror and reflecting it to the third mirror. Image suki Reducing optical mechanism of the canna.