JP2853924B2 - Image scanner reduction optics - Google Patents

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 applied to an image scanner.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing an optical path of a reduction optical mechanism and an arrangement of components in a conventional image scanner.
Cover to prevent light transmission, 4 is the original 2
, A mirror for reflecting and refracting light to change the angle of the optical path, and 12 for performing photoelectric conversion of reflected light from the original 2 via the mirror 8 to convert image information into an electric signal. In addition, a CCD line sensor 13 for supplying to a printer or a display device, etc., 13 is a light-shielding plate for protecting the light source 1 and restricting the amount of reflected light from the original 2 with a slit 13a, and 14 is for transmitting information of the original 2 , C
A lens for forming an image on the CD line sensor 12, 1
5 holds the above 1, 5, 6, 7, 8, and 12 ;
It is a frame configured as one system.

Next, the operation will be described. Light L ₀ illuminated on the original 2 by the light source 1 becomes reflected light L ₁ and travels along the slit opening 13 a of the light shielding plate 13 according to the dashed line.
The reflected light L ₁ is next to L ₂ is refracted at a right angle by a mirror 5, is guided to the mirror 6, is led further to the refracted at right angles L _3, and the mirror 7, is further refracted at a right angle L _4, incident on the lens 14, here reduces the drawn image to the original 2, the light goes straight becomes L ₅ represents, refracted at a right angle by the mirror 8 becomes L _6, imaging on the CCD line sensor 12 Incident on the surface. Here, the reflected light from the document 2 is photoelectrically converted, and the image information is converted into an electric signal. Frame 1
5, the entire reduction optical mechanism is indicated by an arrow A in the figure.
By moving in the direction, the CCD line sensor 12 sequentially reads the information of the document 2 line by line, and the reading of one piece of picture information according to the length of the document is completed. The information converted into the electric signal is supplied to a display device such as a printer or a monitor, and is output as an information signal.

[0004]

Since the conventional reduction optical mechanism is configured as described above, the optical path length is fixed, and the information from the original is always irrespective of the size of the original. An image is formed on the line sensor at a fixed magnification. Therefore, in a document having a short one-line width, the image width on the line sensor is also short, so that the number of absolute pixels is small, and the number of pixels per unit length is also small. There was a problem that the details fell and roughness became noticeable in the details.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide an optical mechanism that can accurately read original information such as pictures, photographs, and characters in detail.

[0006]

SUMMARY OF THE INVENTION A reduction optical mechanism according to the present invention simultaneously moves a lens for forming an image of light and a mirror integrated with the lens and moves the lens.
By rotating another mirror linked to the to change the optical path, and using another three mirrors to reflect and refract light,
The optical path length can be changed.

[0007]

The mirror integrated with the lens according to the present invention is capable of always refracting light going vertically downward from before and after movement to the center of the lens.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In Figure 1, the 6 to perpendicularly refract reflect incident light L _2, together with the connecting rod 17 to the shaft 17a as a fulcrum pivot
Rotatably supported mirrors, 7 causes a right angle refracted reflect incident light L _3, mirror moves linearly a lens 14 integrally with 9-11 receives the light L ₂ to straight by the rotation of the mirror 6 Further, a mirror for extending the optical path length after several refraction reflections , 16 is an arm, one end of which is a long groove 1
Connected to lens 14 via pin 14a that fits into 6a
The other end is connected to the distal end of the connecting rod 17 and the proximal end of the mirror 6.
It is connected to the connection portion via a pin 6a,
The mirror 6 is rotated in conjunction with the linear movement.

Next, the operation will be described. In FIG. 1, light emitted from a light source 1 to a document 2 is reflected,
The slit openings 13a of the shield plate 13 straight in the direction of arrow L _1, refracted at a right angle by the mirror 5, the process proceeds in the direction of the arrow L _2. The light further refracted by 90 ° at the mirror 6 advances as L ₃ , refracts at 90 ° at the mirror 7, advances as indicated by an arrow L ₄ , and enters the lens 14. Lens Light emitted from the 14 further straight as an arrow L _5, and further 90 ° refracted by the mirror 8, as the process proceeds, the light line sensor 12 in the arrow L ₆
And converts the image information of the original 2 into an electric signal. As the reduction optical mechanism constituted by the frame 15 moves linearly in the direction of arrow A in the figure, the line sensor 12 sequentially reads the image information of the document 2 and when the length reaches the designated length, one sheet The reading of the document is completed. In the state of FIG. 1, there is no particular change in the optical path and the optical path length as compared with the conventional reading, but it slightly changes in the state of FIG.

FIG. 2 shows a state in which the lens 14 has moved horizontally to the right as compared to the state shown in FIG. At this time, arm 1
The lens 6 holds the lens 6 at a position rotated clockwise by about 45 °. Light arrow L ₂ in this state, go straight to the mirror 9, where reflected and travels straight in the direction of arrow L _3. The light reflected by the mirror 10 is refracted degree 90 ° by the mirror 11 to go straight in the direction of arrow L _4, straight in the direction of arrow L _5,
The light enters the mirror 7. Hereinafter, the same optical path as that of FIG. 1 is followed.
Therefore, by moving the position of the lens 14, the optical path length is switched in conjunction with this.

[0011]

As described above, according to the present invention, two types of reduction optical paths according to the size of the original can be selected simply by moving the lens. There is an effect that a high pixel can be obtained. Also, the second optical path system is formed in conjunction with the movement of the lens.
Therefore, a highly reliable optical path length can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a reduction optical mechanism according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a state in which a lens and a mirror have been moved from FIG. 1 in one embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional reduction optical mechanism.

[Explanation of symbols]

1 light source, 2 originals, 3 covers, 4 glass plates, 5
11 mirror, 6a rotation axis, 12 line sensor, 1
3 Shielding plate, 14 lenses, 15 frames, 16 arms.

Claims (1)

(57) [Claims] 1. A reduction optical mechanism of an image scanner in which light emitted from a light source and reflected by a document is introduced into a photoelectric conversion unit through an optical system including a plurality of mirrors and a lens. It is provided with two optical path systems, rotates in conjunction with the movement of the lens, and
Mirror provided to selectively use one of the road systems
Reduction optical system of the image scanner, characterized in that.