JPH10243184A - Scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small sized scanner by which a curved original such as a book original is scanned in an excellent way. SOLUTION: A main roller 22 and a sub roller 24 are provided in the subscanning direction at a prescribed distance, and the both are connected via a belt transmission device consisting of a belt 28 and a tension roller 30 so as to drive both the rollers in the same direction interlocking with each other. Then a position sensor 34 that senses rotation is provided at a connected part of both the rollers. Thus, when at least one of the main roller 22 and the sub roller 24 is turned while being in contact with an original 44, the other roller is turned in interlocking with the one roller and the position sensor 34 senses the motion so as to sense a moving amount in the subscanning direction. Or a gear transmission device may be used in place of the belt transmission device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanner,
In particular, while manually moving over the original surface,
The present invention relates to a small scanner that reads a two-dimensional image.

[0002]

2. Description of the Related Art In a handy scanner that reads a two-dimensional image of a document while moving along the document while illuminating the document with a light source, a light from a document surface incident from a reading opening (scan slit) is transmitted through a lens. Via a line sensor (CCD). When a flat document such as a photograph is scanned by a handy scanner of this type, a reading portion of the document is hidden under the scanner, it is difficult to grasp the reading position, and an error in the reading range is likely to occur. In order to eliminate such inconvenience, a thin scanner has been proposed in which the dimension in the sub-scanning direction is shortened so that the portion hidden by the scanner is reduced, and the scanner is used in a vertical type so as to be substantially perpendicular to a document. .

[0003]

However, in a scanner having a short dimension in the sub-scanning direction, as shown in FIG.
When scanning a curved surface such as the book 70, there is a disadvantage that the main roller 72 for detecting the movement amount is easily separated from the scan surface. On the other hand, below the scanner 74, in addition to the main roller 72, an auxiliary roller 76 is provided with a scan slit therebetween. The auxiliary roller 76 moves the scanner 74 in the sub-scanning direction (the direction indicated by the arrow A in the figure). The main roller 72 is free to rotate independently of the main roller 72 without any interlocking relationship with the main roller 72.

Therefore, it is necessary to make the main roller 72 run carefully while confirming that the main roller 72 is always in contact with the original surface (scan surface) during scanning, and the operation is inconvenient. If the user moves away, the movement of the scanner 74 and the rotation of the main roller 72 do not cooperate with each other, resulting in a partial loss or distortion of the image, which causes a problem of deterioration of the scanned image.

The present invention has been made in view of such circumstances, and has as its object to provide a small-sized scanner capable of favorably scanning a curved surface of a book or the like.

[0006]

In order to achieve the above object, the present invention illuminates an original with a light source, and transmits light from the original through a reduction optical system while moving the original in the sub-scanning direction. A scanner that scans a two-dimensional image of the original by guiding it to an image sensor and that is provided at a predetermined distance in the sub-scanning direction from a first roller that can rotate while contacting the original during scanning. A second roller that is rotatable while contacting the document during scanning, and a first roller and a second roller that are connected via a power transmission member, and that are linked to rotate in the same direction. And a position detecting means for detecting a position in the sub-scanning direction based on rotation of the first and second rollers interlocked by the transmission mechanism.

According to the present invention, the first roller and the second roller are provided at a predetermined distance in the sub-scanning direction, and both are connected by a power transmission member such as a belt or a gear. , The rotational force is transmitted to the other roller via the transmission mechanism, and both rollers rotate in the same direction. The position in the sub-scanning direction is detected by the position detecting means based on the rotation. With this, if at least one of the first roller and the second roller is rotating while being in contact with the document,
It is possible to detect the movement in the sub-scanning direction, and it is possible to prevent the image from being partially missing or distorted.

The two rollers are preferably arranged at a distance greater than the irradiation area of the illumination light across the scan slit so as not to block the illumination light emitted from the light source through the scan slit. Further, according to the present invention, the first roller and the second roller rotate in the same direction in conjunction with each other,
By detecting the movement of any one of the first roller, the second roller, and the power transmission member, it is possible to detect the position in the sub-scanning direction.

Further, by making the amount of movement of the first roller equal to the amount of movement of the second roller, the position in the sub-scanning direction can be accurately detected. In particular, if both rollers have the same shape, components can be shared, and there is an advantage that blurring of the transmission system can be reduced.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a scanner according to the present invention. FIG.
1 is a side perspective view of a handy scanner showing an embodiment of a scanner according to the present invention. This scanner 10
A reflective optical unit 14, a lens 16, a CCD image sensor 18, a signal processing board 20, and the like are provided in a casing 12, and a main roller (corresponding to a first roller) 22 and a sub roller ( A second roller 24 is provided at a predetermined distance in the sub-scanning direction (indicated by an arrow A in the figure). Incidentally, reference numeral 2 in the figure
6 is a CCD substrate.

The main roller 22 and the sub roller 24 are
8 and a tension roller 30 are connected via a belt transmission mechanism. The rotational force of one roller is transmitted to the other roller via a belt 28, and the two rollers always rotate in the same direction in conjunction with each other. It has become. The belt transmission mechanism is provided on both sides or one side of the side surface of the main roller 22 and the sub roller 24.

A transmission path of the belt transmission mechanism is provided with an impeller 32 for detecting rotation.
Is provided with a position detection sensor 34 for detecting the number of rotations. The position detection sensor 34 detects the number of rotations of the impeller 32, and detects the amount of rotation of the main roller 22 and the auxiliary roller 24, that is, the amount of movement of the scanner 10 in the auxiliary scanning direction. The same roller is used for the main roller 22 and the auxiliary roller 24, so that parts can be shared. Thereby, the main roller 2
The amount of movement due to the rotation of 2 and the amount of movement due to the rotation of the auxiliary roller 24 become equal, and blurring of the transmission system is reduced.

The reflecting optical unit 14 is composed of a combination of two optical blocks 36 and 38, and each optical block 36 and 38 is formed of a transparent optical plastic. A light source 40 for illumination is incorporated in a side surface of the optical block 36 on the left side in FIG. 1, and light emitted from the light source 40 passes through the inside of the optical block 36 and is emitted from the illumination light emission surface 36a. .

A scan slit 42 is formed substantially at the center of the bottom surface of the casing 12, and the light emitted from the illumination light exit surface 36a is applied to the original 44 via the scan slit 42. . The light source 40 is, for example, a light emitting diode (LED) array, a fluorescent lamp, or the like. Main roller 22 and sub roller 2
Reference numeral 4 is arranged at a distance greater than or equal to the irradiation area of the illumination light across the scan slit 42 so as not to block the illumination light emitted through the scan slit 42.

The opposing surfaces of the optical blocks 36 and 38 are respectively provided with reflecting surfaces 52 and 54 having a length L1.
And a reflecting surface 56 having a length L2 (> L1) orthogonal to this,
58 are formed. The two blocks are arranged such that reflection surfaces of the same length face each other in parallel, and are fixed to the casing 12 by a fixing member (not shown). With this arrangement, a reflective optical system is formed that includes a pair of parallel reflecting surfaces 52 and 54 having a length L1 and a pair of parallel reflecting surfaces 56 and 58 having a length L2 (> L1).

The two optical blocks 36 and 38 are arranged at a predetermined distance (W) apart from each other, and a reflecting surface 52 and a reflecting surface 5 are provided.
An opening corresponding to a light incident port is formed at the intersection of 8 and an opening corresponding to a light exit is formed at the intersection of the reflection surface 54 and the reflection surface 56. The entrance and exit are formed in such a size that they do not hinder the reflection of each of the reflection surfaces 52, 58, 54, 56.

As described above, by restricting the width of the entrance, it is possible to prevent unnecessary light from entering while securing necessary light. Further, there is an advantage that an appropriate amount of emitted light can be obtained in accordance with the width of the emission port. If the width of the exit is small, the amount of light in the sagittal direction is reduced and the resolution is reduced. Therefore, it is necessary to determine the width of the exit so that a sufficient amount of light in the sagittal direction can be obtained.

The reflected light from the document 44 illuminated by the light source 40 is guided into the casing 12 from the scan slit 42 and enters the reflection optical unit 14 from the entrance. The light incident on the reflection optical unit 14 is reflected rightward by 90 degrees in the drawing on the reflection surface 56, and thereafter,
Reflecting surfaces 54, 58, 52, 56, 58, 54, 56, 5
The light is reflected in the order of 2 and 58, and is finally emitted from the reflection optical unit 14 from the emission port.

A lens 16 and a CCD image sensor 18 are provided above the exit of the reflection optical unit 14. With such an optical arrangement, an optical path of a reduction optical system for guiding the reflected light from the document 44 illuminated by the light source 40 to the CCD image sensor 18 via the reflection optical unit 14 and the lens 16 is formed. The CCD image sensor 18 is provided with a light receiving portion for a predetermined number of pixels in a direction (perpendicular to the paper) perpendicular to the traveling direction of the scanner 10 (direction indicated by arrow A in the figure). The image light formed on the light receiving surface 18 is charged in each light receiving unit and converted into signal charges in an amount corresponding to the light intensity.

Light incident on the light receiving surface of the CCD image sensor 18 is converted into an electric signal corresponding to the light intensity, and the electric signal is guided to the signal processing board 20. Then, in the signal processing board 20, a two-dimensional image of the document 44 is obtained by operating a known image signal processing circuit in synchronization with a signal of the amount of movement in the sub-scanning direction from the position detection sensor 34.

In addition, on the signal processing board 20, in addition to the image signal processing circuit, various electronic circuits such as a light source driving circuit for turning on / off the light source 40 and a memory for storing image data are formed. Next, the operation of the handy scanner configured as described above will be described. Scanner 10
Is placed on a document 44 and a start switch (not shown) is pressed to cause the document 44 to travel rightward (sub-scanning direction) in FIG. 1 so that at least one of the main roller 22 and the sub-roller 24 Rotates in contact with. When the document 44 is flat, both rollers rotate while contacting the document 44. In this case, the distance between the scanner 10 and the surface of the document 44 is kept constant by the two rollers, and the moving direction of the scanner 10 is regulated, so that the scanner 10 moves smoothly in the sub-scanning direction.

Then, the position detecting sensor 3 based on the rotation of the impeller 32 interlocked with the main roller 22 and the sub-roller 24.
4, the amount of movement of the scanner 10 is detected, and the light from the document 44 is sequentially captured by the CCD image sensor 18 via the above-described reflection optical unit 14 and the lens 18 while grasping the position of the scanner 10. When the movement of the reading range is completed, the start switch is released and the reading is completed. Thus, a two-dimensional image of the document 44 can be obtained.

Further, even when the scan target is a curved surface such as a book (see FIG. 3), the main roller 22 and the auxiliary roller 2
If any one of the rollers 4 contacts the original and rotates, the rotational force is transmitted to the other roller via the transmission mechanism, and both rollers rotate in the same direction. The position detection sensor 34 detects the position in the sub-scanning direction based on the rotation. As a result, if at least one of the main roller 22 and the auxiliary roller 24 is rotating while being in contact with the document, the amount of movement in the sub-scanning direction can be detected, and the occurrence of partial missing or distortion of the image can be detected. There is an advantage that can be prevented.

In the above embodiment, the case where the main roller 22 and the auxiliary roller 24 are connected by the belt transmission mechanism has been described as an example. However, other transmission mechanisms may be employed instead of the belt transmission mechanism. FIG. 2 shows an example in which a gear transmission mechanism is employed instead of the belt transmission mechanism shown in FIG. As shown in FIG. 2, the main roller 22 and the sub roller 2
4 is connected via a connection gear 60 and is configured to rotate in conjunction with the same direction. And the connecting gear 60
The position detection sensor 34 is provided on the gear 62 in a part of the main roller 22 to detect the rotation of the main roller 22 and the auxiliary roller 24. With such a configuration, if at least one of the main roller 22 and the sub-roller 24 is rotating while being in contact with the document 44, the amount of movement in the sub-scanning direction can be detected, and a partial lack of an image or The occurrence of distortion can be prevented.

In each of the above-described embodiments, the case where rotation is detected from a part of the connection system between the main roller 22 and the sub-roller 24 has been described. The rotation of the main roller 22 or the sub roller 24 may be directly detected by providing a sensor 34 or the like. In the above embodiment, the pair of optical blocks 36, 3
8 has been described as an example in which an optical path for guiding light from the document 44 to the lens 16 is formed, but the invention is not limited thereto.
The optical path may be formed using a mirror.

[0026]

As described above, according to the scanner of the present invention, the first roller and the second roller which are arranged at a predetermined interval in the sub-scanning direction are connected by the power transmission member, and one of the rollers is connected. The other roller is also configured to rotate in conjunction with the rotation of the roller, and the position in the sub-scanning direction is detected based on the rotation. Therefore, at least one of the first roller and the second roller is driven by the original. If it rotates while contacting with the camera, movement in the sub-scanning direction can be detected.

Thus, it is sufficient that at least one of the rollers is in contact with the document surface during scanning, so that the operation of moving the scanner is facilitated, and there is an advantage that occurrence of partial loss or distortion of an image can be prevented. .

[Brief description of the drawings]

FIG. 1 is a side perspective view of a handy scanner showing an embodiment of a scanner according to the present invention.

FIG. 2 is a side perspective view of a handy scanner according to another embodiment of the present invention.

FIG. 3 is a side view showing an example of a usage mode of the handy scanner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Scanner 12 ... Casing 14 ... Reflective optical unit 16 ... Lens 18 ... CCD image sensor 22 ... Main roller (1st roller) 24 ... Sub-roller (2nd roller) 28 ... Belt 30 ... Tension roller 32 ... Impeller 34 ... Position detection sensor 40: light source 44: original 60: connecting gear

Claims (6)

[Claims] 1. A scanner for illuminating a document with a light source, guiding light from the document to an image sensor through a reduction optical system while moving the document in the sub-scanning direction, and reading a two-dimensional image of the document. A first roller that is rotatable while contacting the document during scanning travel; and a first roller that is provided at a predetermined distance from the first roller in a sub-scanning direction and that is rotatable while contacting the document during scanning travel. A second roller, a transmission mechanism for connecting the first roller and the second roller via a power transmission member, and linking the two to rotate in the same direction; and the first and second linkages interlocked by the transmission mechanism. And a position detecting means for detecting a position in the sub-scanning direction based on rotation of the roller. 2. The scanner according to claim 1, wherein the power transmission member is a belt or a gear. 3. An illumination light emitted from the light source is applied to the original via a scan slit for taking in light from the original into the reduction optical system, and the first roller and the second roller 2. The scanner according to claim 1, wherein the scanner is disposed at a distance greater than a region irradiated with the illumination light across the scan slit so as not to block the illumination light emitted from the slit. 4. The apparatus according to claim 1, wherein the position detecting means includes: a first roller;
2. The scanner according to claim 1, wherein a movement of any one of a second roller and the power transmission member is detected. 5. The scanner according to claim 1, wherein the amount of movement in the sub-scanning direction with respect to the amount of rotation of the first roller is equal to the amount of movement in the sub-scanning direction with respect to the amount of rotation of the second roller. . 6. The scanner according to claim 1, wherein the first roller and the second roller use members having the same shape.