JPH05252347A - Color scanner - Google Patents

Abstract

PURPOSE:To obtain a color scanner capable of improving the resolution of a small original while maintaining a compact and light weight body at a low cost and setting up a proper magnification in accordance with the reading size of the original. CONSTITUTION:A moving member 38 is supported by an eccentric cam 52 and vertically moved by rotating an operation knob 60. On the uppermost position of the member 38, a magnification changing mirror 34 is retreated from an optical path and the smallest state of the magnification is set up (resolution 1600 dpi). On the intermediate position of the member 38, a mirror face 34A is arranged on the optical (800 dpi). On the lowermost position of the member 38, a mirror face 38B is arranged on the optical path and the largest state of the magnification is obtained (400 dpi). Since a lens 30 and a photodetecting element 32 are moved together with the mirror 34, light is made vertically incident upon the lens 30 and the element 32 in any magnification. A bracket 42 supporting lens 30 is guided to the a cam face 72 in accordance with the rotation of the cam 52 and moved to a focal position based upon each magnification change.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention linearly scans an image of a document placed on a document table and reads it by a light receiving element in which a predetermined number of pixels are arranged in the main scanning direction through a mirror and a lens.
The present invention relates to a color scanner for image processing.

[0002]

2. Description of the Related Art In recent years, with the spread of image processing computers, images are read by a reflection type flat bed scanner and are widely used for color page layout and creative design.

The feature of the reflection type flat bed scanner is that it is small, lightweight and inexpensive. Therefore, it is easily used in a relatively small design studio. The low-cost reflective flatbed scanner has a resolution of about 300 dpi to 400 dpi, and when an A4 size document is applied as an image size, it can be read by the entire light receiving element.

Therefore, when reading an image on a 35 mm size reversal film (slide film),
Since the magnification is the same as that of an A4 size original, the number of read pixels is small and the resolution is low when the image is enlarged and used. That is, the image is read by only a part of the light receiving element, and the smaller the original is, the lower the resolution in the case of enlarging and using it.

Here, when a large document size and a small document size are output on image-receiving papers of the same size and both are used in superposition, for example, when a photograph is added to a document, characters are not printed. A clear image can be output when scanned in A4 size, but since the image size of a 35 mm film photograph is originally small, it will be enlarged and used. When comparing the two, the photograph may appear blurred.

In order to increase the resolution, the original document may be enlarged and read. In a relatively high-class image scanner equipped with a means for enlarging the magnification of this document,
Applying a zoom lens. This zoom lens is generally the same as that used in copying machines.

However, since the zoom lens is expensive and not suitable for a low-cost reflective flatbed scanner, it is necessary to change the magnification with a simpler structure. As the magnification changing means, the optical path length from the document to the light receiving element may be changed.

According to this, the original can be enlarged only by moving the optical means such as a mirror, and even a small-sized original can be read over the entire area of the light receiving element.
The resolution can be increased.

[0009]

However, in the moving mechanism of the conventional optical means, the optical axis is vertically incident on the fixedly arranged light receiving element, and the optical path is kept constant regardless of the magnification. , The optical path length is changed. For this reason, it is necessary to secure the optical path length of the maximum magnification in advance, the entire apparatus becomes large, and the features of the reflection type flat bed scanner, which is small, lightweight and inexpensive, are impaired. Etc.) will not be met.

Further, the magnification change is arbitrarily selected by the operator regardless of whether the zoom lens is changed or the optical path length is changed, and it may not always be an appropriate magnification for the size of the original to be used.

In consideration of the above facts, an object of the present invention is to obtain a color scanner capable of enhancing the resolution of a small original while maintaining its small size, light weight and low cost.

In addition to the above object, it is another object to obtain a color scanner capable of setting an appropriate magnification according to a reading size on a document.

[0013]

According to a first aspect of the present invention, an image of a document placed on a document table is line-scanned and a predetermined number of pixels are arranged in the main scanning direction via a mirror and a lens. It is a color scanner for reading with a light receiving element and for image processing, reflecting the light by retracting the mirror on the optical axis and changing the optical path to increase or decrease the optical path length within a predetermined area and to change this optical path. Regardless of the moving means for moving the lens and the light receiving element so that the optical axis is incident at a right angle, the lens is moved in the optical axis direction based on the moving amount of the mirror and the light receiving element moved by the moving means to focus the light. And focusing means for adjusting.

The invention according to claim 2 is characterized by having a cam mechanism portion for simultaneously moving the moving means and the focusing means.

According to a third aspect of the invention, a color scanner for line scanning an image of an original placed on an original table and reading the image with a light receiving element having a predetermined number of pixels arranged in the main scanning direction for image processing. The magnification setting means for setting the magnification so that the resolution of the read image corresponds to the number of pixels of the light receiving element according to the size of the original, and the magnification setting means operated in conjunction with the magnification setting means. And an optical means for setting the magnification to a set value.

[0016]

According to the first aspect of the invention, the document is placed on the document table and the image recorded on the document is line-scanned.
The line-scanned image reaches the light receiving element via the mirror and the lens, and the image is read by the light receiving element for each main scanning.

Here, when the image to be placed on the document table is large (for example, A4 size), the light receiving element can read the image with the entire pixels arranged in the main scanning direction.

However, when the original placed on the original table is small or only a part of the original is applied (for example, a 35 mm reversal film or a part of A4 size original), the resolution is the same, and therefore the pixel of the light receiving element is It will be read in only a part of.

Then, the mirror is projected and retracted on the optical axis to extend the optical path length, and the image is enlarged and read by the light receiving element. At this time, if the optical path length is extended within a predetermined area, the lens and the light receiving element may be displaced from the optical path extension depending on the magnification. Therefore, the lens and the light-receiving element are moved integrally with the movement of the mirror by the moving means. As a result, the lens and the light receiving element can be arranged on the optical path extension whose direction has been changed by changing the magnification.
Further, based on this movement amount, the focusing means moves the lens in the optical axis direction to focus.

Since the lens and the light receiving element are moved and the focus is adjusted in conjunction with the movement of the mirror, the positioning is easier than the case where the mirror and the light receiving element are moved separately. The image can be read.

Further, since the optical path length can be extended within a predetermined area in this manner, the conventional features of small size and light weight are not impaired, and it is equivalent to a high-end model using expensive parts such as a zoom lens. Can be equipped with the function of.

According to the second aspect of the invention, in the cam mechanism section, the movement of the mirror and the light receiving element by the moving means and the movement of the lens by the focusing means are integrally moved. By driving the cam mechanism, it is not necessary to separately move the moving means and the focusing means, and the accuracy is improved.

According to the third aspect of the invention, usually, the operator arbitrarily sets the magnification change of the image. However, when it is desired to keep the resolution of the output image substantially constant, there is an appropriate magnification according to the read image size. That is, regardless of the size of the image, the image can be read over the entire area of the light receiving element (all pixels in the main scanning direction).

Here, the magnification setting means sets the magnification so that the resolution of the read image corresponds to the number of pixels of the light receiving element according to the document size. The optical means adjusts the magnification in cooperation with the magnification setting means. As a result, the image to be read is read at the optimum resolution, and workability is good.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a color scanner 10 according to this embodiment. A rectangular opening 14 is formed on the top surface of the casing 12 of the color scanner 10, and a transparent glass plate 16 is fitted therein. The original 18 is placed on the glass plate 16.

Corresponding to the glass plate 16, a cover 20 is provided on one side (short side) of the opening 14 so as to be opened and closed via a hinge (not shown). The lid 20 is a manuscript 1
8 is placed on the glass plate 16 and is closed (see the phantom line in FIG. 1).

As shown in FIG. 2, a plurality of scanning light sources 22 are arranged below the glass plate 16. The light source 22 has a cylindrical shape and extends in the width direction (main scanning direction) of the document 18. Original 1 which is the initial position of this light source 22
The image recorded on the document 18 can be line-scanned by moving from one end to the other end in the longitudinal direction of 8 along the surface of the glass plate 16 (sub-scanning).

The reflected image reflected by the light source 22 is reflected by the first mirror 24 that is moved integrally with the light source 22 and is deflected to the left in FIG. 2, and further the second and third mirrors 26, It is reflected by 28 and is deflected in the downward direction and the rightward direction in FIG. Here, the second and third mirrors 26, 28
Of the first mirror 24 are moved by half the movement amount of the first mirror 24 in the same time, whereby the optical path length to the lens 30 becomes constant in the scanning image of the entire area of the original 18.

It is also possible to adopt a structure in which all the members including the second and third mirrors 26 and 28 except the glass plate 16 and the original 18 of FIG. 2 are moved at the same time.

A light receiving element 32 is arranged downstream of the lens 30. The light receiving element 32 is composed of a CCD line sensor in which a plurality of pixels are arranged in the main scanning direction of the document 18, and reads an image line by line and supplies the image information to a controller (not shown). ing. Therefore, by scanning the document 18 line by line, the image is sequentially read line by line.

On the optical path between the third mirror 28 and the lens 30, mirror surfaces 34A and 3A having different reflection angles from each other.
A magnification changing mirror 34 having 4B is arranged so that it can appear and disappear. The magnification changing mirror 34 is attached to a bracket 36, and the bracket 36 is fixed to an intermediate portion of a moving member 38 arranged parallel to the optical axis.
Both ends of the moving member 38 in the longitudinal direction are housed in rail grooves (not shown) of a pair of rail members 40 arranged in the vertical direction in FIG. Therefore, the moving member 38 is guided by the rail groove of the rail member 40 and is movable in the vertical direction (arrow A direction) in FIG.

The lens 30 and the light receiving element 32 are also attached to the moving member 38 via brackets 42 and 44, respectively. Here, the bracket 42 that supports the lens 30 is provided with a hole 46 whose axial line is parallel to the moving member 38, and the moving member 38 is inserted therethrough. Therefore, the bracket 42 is movable relative to the moving member 38 in the longitudinal direction of the moving member 38. Further, the L attached to the bracket 42 and the moving member 38
Both ends of the tension coil spring 50 are attached between the bracket 42 and the bracket 48, and the bracket 42 is attached to the bracket 42 as shown in FIG.
Is urged in the right direction (direction of arrow B).

The moving member 38 is supported by the outer peripheral surface of the eccentric cam 52. The eccentric cam 52 has the eccentric shaft 5
4 extends in the vertical wall direction of the casing 12. A bracket 56 is arranged on the inner peripheral surface side of the vertical wall of the casing 12, a circular hole 58 is formed, and the eccentric shaft 54 is pivotally supported in the circular hole 58.

The eccentric shaft 54 penetrates the vertical wall of the casing 12 and projects outward. An operation knob 60 is fitted to the tip of the eccentric shaft 54 protruding outward, and the eccentric cam 52 can be rotated by rotating the operation knob 60.

Due to the rotation of the eccentric cam 52, the distance from the eccentric shaft 54 to the supporting point of the moving member 38 is changed, and the moving member 38 supported by the eccentric cam 52 by its own weight is Following this, it is moved in the vertical direction (arrow A direction) in FIG.

During operation of rotating the operation knob 60, it can be temporarily fixed at three positions by a click mechanism (not shown).

That is, at the first point (switch 1), the moving member 38 is at the uppermost position (solid line position in FIG. 2), the magnification changing mirror 34 is at the position retracted from the optical path, and the optical path length is the shortest. That is, the state becomes the state in which the magnification is the smallest. Therefore, the resolution of the output image based on the document 18 is high and is 1600 dpi. In this case, the mirrors present on the optical path are the first, second and third mirrors 24, 26,
28.

At the second point (switching 2), the moving member 38 is at the intermediate position in the vertical direction (the position indicated by the alternate long and short dash line in FIG. 2), and the mirror surface 34A of the magnification changing mirror 34 is located at the optical path. Thus, the magnification is twice that of the switching 1. Therefore, the resolution of the output image based on the original is 800 dpi.

At the third point (switch 3), the moving member 38 is at the lowest position (imaginary line position in FIG. 2), and the mirror surface 34B of the magnification changing mirror 34 is at the position on the optical path. , The highest magnification is achieved. Therefore, the resolution of the output image based on the original document 18 is low and is 400 dpi.

The reflection angle at the mirror surface 34A is an acute angle, and the fourth mirror 62 is arranged on the optical path in this reflection direction. The optical axis of the optical path reflected by the mirror surface 34A by the fourth mirror 62 is the third mirror 2 described above.
It is arranged to be parallel to the optical axis of the optical path reflected by 8.

On the other hand, the reflection angle at the mirror surface 34B is a right angle, and the fifth, sixth and seventh mirrors 64, 66 and 68 are arranged on the optical path in this reflection direction. With the fifth, sixth and seventh mirrors 64, 66, 68,
The optical axis of the optical path reflected by the mirror surface 34B is deflected clockwise every 90 ° (as a result, a deflection of 270 °) so as to be parallel to the optical axis of the optical path reflected by the third mirror 28. Is becoming

That is, the optical path length can be changed by changing the switching position of the operation knob 60. Here, the lens 30 and the light receiving element 32
Is moved along with the magnification changing mirror 34 by the movement of the moving member 38, so that it is vertically incident on the lens 30 and the light receiving element 32 in any optical path.

On the surface of the eccentric cam 52 opposite to the side on which the eccentric shaft 54 is attached, a cylindrical portion 70 is formed so as to project along the outer circumference of the eccentric cam 52. The dimension of the cylindrical portion 70 up to the tip of the protrusion changes in the axial direction and serves as a cam surface 72. A lower end portion of a bracket 42, in which the lens 30 is attached to the moving member 38, is in contact with. Therefore, as the eccentric cam 52 rotates, the bracket 42 is guided while being kept in contact with the cam surface 72 by the urging force of the tension coil spring 50, and is guided in the left-right direction (parallel to the optical axis) in FIG. Direction). This amount of movement is
It corresponds to the focal position with each magnification change. That is, as the magnification increases, it approaches the light receiving element 32 side.

The operation of this embodiment will be described below. First,
When scanning a document 18 of a relatively small size (for example, 35 mm film) for image processing, first, the document 1
8 is placed on the glass plate 16 and the lid 20 is closed.

Next, the magnification for receiving the original of this size using the entire area of the light receiving element 32 is set. In this case, the operating knob 60 is rotated and set to the switching 1 having the smallest magnification.

Here, when the scan start button is operated, the light source 22 and the first mirror 24 are moved in parallel with the glass plate 16 along the longitudinal direction of the document 18, and line scanning is performed. The line-scanned reflected light is divided into the second and third
The mirrors 26 and 28 of No. 2 reach the lens 30 as shown by the solid line in FIG.

The second and third mirrors 26, 28
Interlocks with the movement of the light source 22 and the first mirror 24,
The optical path length up to the lens 30 does not change because it moves half the distance in the same time.

As shown in FIG. 2, in the switching 1 state,
Since the magnification changing mirror 34 is not arranged on the optical path, the optical path length reaches the lens 30 in the shortest state. The scanning image is transmitted through the lens 30 and is received by the light receiving element 32. The image information received by the light receiving element 32 is output after being subjected to predetermined image processing. This output image is
Since the magnification is the smallest, the resolution is 1600 dpi and a clear image can be obtained. Since the document size is small and the amount of image information is small, the image processing does not take time.

Next, when scanning a relatively large document (A4 size, for example) 18, the light receiving element 32 needs to maximize the magnification so that the entire area of the document 18 is received. Therefore, the operation knob 60 is rotated to
Switch 3 is set.

When the operation knob 60 is rotated, the eccentric shaft 5
The eccentric cam 52 is rotated via 4. Therefore, the moving member 38 supported on the outer periphery of the eccentric cam 52 moves downward along the rail member 40 (see the imaginary line in FIG. 2), and the magnification changing mirror 34 moves to the lowermost position as the imaginary line in FIG. To the position. In this state, since the mirror surface 34B is on the optical path, the light reflected by the third mirror 28 is reflected by this mirror surface 34B and further the fifth, sixth, and seventh mirrors 64, 66, 68. Is reflected in the clockwise direction by 270 ° to reach the lens 30 direction. The optical axis in this case is parallel to the optical axis when the magnification changing mirror 34 is not on the optical path,
Its position is displaced downward in FIG. However, in this embodiment, since the lens 30 and the light receiving element 32 move together with the magnification changing mirror 34 by the same amount when the moving member 38 moves,
The light reflected by the seventh mirror 68 enters the lens 30 and the light receiving element 32 at a right angle.

By the way, when the magnification changes, the focal length also changes. Therefore, the eccentric cam 52 is formed with a cylindrical portion 70, and the bracket 42 of the lens 30 is in contact with the protruding tip of the cylindrical portion 70 by the urging force of the tension coil spring 50. Since the protruding tip of the cylindrical portion 70 is the cam surface 72, when the eccentric cam 52 rotates, the bracket 42
Can be moved in the axial direction of the eccentric cam 52.
Therefore, the lens 30 is moved along the optical axis. Since the cam surface 72 is formed in advance based on the set magnification, the lens 30 is moved so that the focal length matches.

The image information received by the light receiving element 32 is output after being subjected to predetermined image processing. The output image has the largest magnification and thus has a resolution of 400 dpi. However, since the size of the document 18 itself is large, the image quality is not deteriorated. Further, since the amount of image information is small, the image processing does not take time.

In the case of a document 18 of an intermediate size of the above-mentioned two types of documents, the operation knob 60 is set to the switching 2 to change the magnification changing mirror 3 as shown by the one-dot chain line in FIG.
The fourth mirror surface 34A is arranged on the optical path. At this time,
Since the lens 30 and the light receiving element 32 move at the same time, the light reflected by the mirror surface 34A and the seventh mirror 62 enters the lens 30 and the light receiving element 32 at a right angle.

As described above, by changing the magnification according to the size of the original, it is possible to shorten the image processing time for each size alone and obtain an appropriate resolution. Further, when the originals 18 having different sizes are used and output on the same image receiving paper, for example, the characters or logo of the catalog are A4 size.
In the case of reading from the size and adding a photograph to this catalog, the resolution (constant resolution: 400 dpi) has been constant in the past, so that a small-sized document (photograph) tends to be blurred. However, in the present embodiment, since the magnification is changed according to each size, it is possible to sharpen the image of a small size original without extremely lengthening the image processing time.

The compatibility table with the resolution of the output image in each size is shown below. In addition, ○ mark is conformity, X mark is nonconformity,
Δ means unfavorable.

[0056]

[Table 1]

In Table 1 above, x₍₁₎Has too few pixels,
A good image cannot be obtained. Also × ₍₂₎Has many pixels
However, there is a problem that the image processing time becomes long.

According to the present embodiment, the optical path length is changed in accordance with the change of magnification in order to solve the above-mentioned problems in a relatively small space, and the displacement of the optical path is changed accordingly, and the magnification changing mirror 34, lens 30 and Since the correction is performed by simultaneously moving the light receiving elements 32 by the same amount, the apparatus can be kept compact and expensive components such as a zoom lens are unnecessary.

Further, the smaller the magnification is, that is, the higher the resolution is, the smaller the number of reflections by the mirror is.
Little deterioration in image quality.

In the present embodiment, the operation of the operation knob 60 is left to the operator's judgment. However, as shown in FIG. 3, the operation knob 60 is provided with an instruction line 74 in advance and corresponds to the instruction line 74. Then, a panel 76 indicating the matching position of each size is attached to the casing 12, and the glass plate 16
By rotating the operation knob 60 to a position corresponding to the original placed on the document, an appropriate magnification can be set. Further, an automatic mode may be added so that the document size is automatically read and the magnification is automatically changed.

[0061]

As described above, the color scanner according to the present invention has an excellent effect that the resolution of a small original can be increased while maintaining the small size, the light weight and the low cost.

In addition to the above effects, there is an effect that an appropriate magnification can be set according to the reading size on the original.

[Brief description of drawings]

FIG. 1 is a perspective view of a color scanner according to this embodiment.

FIG. 2 is a side view showing a drive mechanism of an optical system for changing a magnification.

FIG. 3 is a front view of an operation knob according to a modification.

[Explanation of symbols]

 10 Color Scanner 18 Original Document 24 First Mirror 26 Second Mirror 28 Third Mirror 30 Lens 32 Photosensitive Element 34 Magnification Changing Mirror (Optical Means) 38 Moving Member (Movement Means) 40 Rail Member (Movement Means) 52 Eccentric Cam (Cam mechanism part) 60 Operation knob (magnification setting means) 62 Fourth mirror 64 Fifth mirror 66 Sixth mirror 68 Seventh mirror 70 Cylindrical part (focusing means) 72 Cam surface (focusing means) 74 Indicator line (magnification setting means) 76 panel (magnification setting means)

Claims (3)

[Claims] 1. A color scanner for line-scanning an image of a document placed on a document table, reading the image through a mirror and a lens with a light receiving element having a predetermined number of pixels arranged in the main scanning direction, and performing image processing. Then, by reflecting the light by the appearance of the mirror on the optical axis to change the optical path to increase or decrease the optical path length within a predetermined area and to make the optical axis incident at a right angle regardless of the change of the optical path, the lens and A color scanner comprising: moving means for moving the light receiving element; and focusing means for moving the lens in the optical axis direction to focus on the basis of the moving and retracting movement of the mirror by the moving means and the moving amount of the light receiving element. 2. The color scanner according to claim 1, further comprising a cam mechanism unit that simultaneously moves the moving unit and the focusing unit. 3. A color scanner for line scanning an image of a document placed on a document table, reading the image with a light-receiving element having a predetermined number of pixels arranged in the main scanning direction, and performing image processing. Magnification setting means for setting the magnification so that the resolution of the read image corresponds to the number of pixels of the light receiving element in accordance with the size, and an optical that operates in conjunction with the magnification setting means and has the magnification set by the magnification setting means. A color scanner having means.