JP2928895B2 - Hand scanner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hand scanner capable of performing high-precision reading while suppressing the reading speed of a document to a certain fixed speed or less.

[0002]

2. Description of the Related Art In personal computers and word processors, a hand scanner is used when inputting image data such as charts and graphs. FIG. 8 schematically shows the structure of a conventional hand scanner. The hand scanner 1 scans by moving forward in the direction A while keeping the start / copy button 2 depressed. At this time, the scanner roller 3 provided at the bottom rotates in the direction B. The rotation speed of the scanner roller 3 is detected by a rotary encoder unit 4 provided in the main body, and a document is read at a speed corresponding to this speed.

[0003]

The hand scanner 1 comprises:
If the rotation speed of the scanner roller 3 exceeds a certain speed, the reading of the original may not be completed in time, and the recorded image may be reduced. For this reason, it is urged by a manual or the like that it is necessary to pay sufficient attention in scanning so as not to be too fast.

However, since the scanner roller 3 has a light load structure, the scanning speed may be high depending on the person, and there is a problem that a recorded image is shrunk and a stable read image cannot be obtained.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hand scanner which suppresses a scanning speed from being too high, and can obtain a stable and highly accurate read image.

[0006]

According to the present invention, a scanner roller 3 is provided at the bottom of a casing so as to roll on a surface to be scanned by scanning, and the rotational speed of the scanner roller 3 is detected by a rotary encoder unit 4. In a hand scanner that reads a document on a surface to be scanned in accordance with this speed, one end of the scanner roller 3 rotates integrally with the central axis of the scanner roller 3 and is provided at a fixed position in the axial direction of the central axis. A clutch plate 10 integrally formed with a projection 16 having a spherical surface protruding on the side opposite to the scanner roller 3 in the axial direction, and slidably in the axial direction on the central axis, and
A brake plate 11 which is fitted non-rotatably about an axis and has a concave portion 17 in which a projection 16 is removably fitted in an engagement surface portion on the clutch plate 10 side, and an elastic body, A brake pad 12 attached to an end surface opposite to the clutch plate 10; and a friction plate 13 made of an elastic body and fixed at a position parallel to and opposed to the brake pad 12.
And a spring 15 that is interposed between the brake pad 12 and the friction plate 13 and generates a spring force in a direction separating the brake pad 12 and the friction plate 13.
The distance x1 between the brake pad 12 and the friction plate 13 in a state where the
The hand scanner is selected to be less than a projection amount X2 of the projection 16 in a state where the projection 16 is in contact with the engagement surface portion after detaching from the engagement surface portion.

[0007]

According to the present invention, when the scanner roller rotates above a certain speed, a braking force acts on the scanner roller. Even if the operator tries to move the hand scanner quickly, a heavy braking load is applied via the scanner roller. As a result, the operator can be informed that scanning cannot be performed at a speed higher than a certain speed, and the rotation speed of the scanner roller itself is limited, so that a stable read image can be obtained.

In particular, according to the present invention, when the rotational speed of the scanner roller 3 increases and sudden acceleration occurs, the clutch plate 10
The protrusion 16 formed on the brake plate 11 is separated from the concave portion 17 formed on the brake plate 11 against the spring force of the spring 15. As a result, the brake pad 12 made of an elastic body and the friction plate 13 made of an elastic body are compressed and distorted, so that a large frictional force is generated between the brake pad 12 and the friction plate 13, and the brake plate 11, and hence the scanner roller The rotation of 3 is stopped. Therefore, the scanner roller 3 can perform the reading operation at a rotation speed as high as possible within a range in which the image on the scanned surface can be read, and the performance of the hand scanner can be utilized.

[0009]

FIG. 1 is a perspective view of the external appearance of a configuration on which the present invention is based. A horizontally long cubic hand scanner 1 extending in a direction perpendicular to the scanning direction A is provided with a start / copy button 2 on an upper surface portion. A rotary encoder unit, a close contact sensor unit, and a scanner roller (not shown) are housed in the casing.

FIG. 2 is a front view showing the structure of the scanner roller 3. The scanner roller 3 is rotatably supported at the bottom of the casing of the hand scanner 1 and is provided so as to be able to roll when scanning on the surface to be scanned. The scanner roller 3 has central axes protruding from both ends and is rotatably supported by both central axes. The gear fitted to one central shaft and the gear fitted to the rotary shaft of the rotary encoder 4 are meshed. The rotation speed of the scanner roller 3 can be detected by the rotary encoder 4. At the end of the other central axis of the scanner roller 3,
As an idler, for example, an idler gear 5 is fitted,
A disk 6 made of a rubber disk is attached to a side surface of the gear 5.

A friction plate 7 made of a rubber disk is provided coaxially with the rubber disk 6. The rubber disk 7 is attached to a mounting bracket 8 provided on the main body of the hand scanner so as to be movable in the direction of the center axis of the scanner roller 3 on the side of the idler gear 5, and comes into surface pressure contact with the rubber disk 6. Or with a small gap. A solenoid 9 is connected to the mounting bracket 8. When the solenoid 9 is excited, the mounting bracket 8 moves rightward in FIG.
Come into surface contact with an appropriate pressure. Solenoid 9
Is released, the rubber disk 7 and the rubber disk 6 move away from each other to the left.

In the configuration shown in FIG. 2, a brake device is formed by the rotary encoder 4, the rubber disks 6, 7, the mounting bracket 8 and the solenoid 9, and a friction plate moving means is formed by the mounting bracket 8 and the solenoid 9. . When the hand scanner 1 is scanned, the scanner roller 3 rolls on the surface to be scanned. When the rotary encoder 4 detects that the rotation speed exceeds a certain speed, the solenoid 9 is excited based on the detection signal. As described above, the rubber disk 7 and the rubber disk 6 are pressed by this operation. As a result, a load is applied to the central axis of the scanner roller 3. As a result, when the hand scanner 1 is operated, a load in the braking direction is applied to the scanner roller 3 so that the rotation speed is suppressed, and the speed does not rise above a certain speed.
A stable read image can be obtained.

FIG. 3 is a front view showing the structure of the scanner roller 3 according to one embodiment of the present invention. Figure 2 shows the structure
And the corresponding parts have the same reference characters allotted. It should be noted that the brake device attached to the scanner roller 3 includes a clutch plate 10, a brake plate 11, a brake pad 12,
The friction plate 13, the support member 14, and the spring 15 are constituted.

In this hand scanner, as described above,
The rotation speed of the scanner roller 3 is detected by the rotary encoder unit 4, and the document is read at a speed corresponding to this speed.

FIG. 4 is an enlarged view of the brake device in a free state. The clutch plate 10, the brake plate 11, and the brake pad 12 are fitted on the central axis of the scanner roller 3, and the clutch plate 10 is rotatable integrally with the central axis and fitted at a fixed position in the axial direction of the central axis. Is done. The brake plate 11 is slidable in the axial direction with respect to the central axis, and
It is fitted so that it cannot rotate around the axis. Further, the brake pad 12 is attached to an end surface of the brake plate 11 on the side opposite to the clutch plate 10. The friction plate 13 is a brake pad 12
The same structural shape as that described above is used, attached to the support member 14, and fixed at a position facing the brake pad 12 in parallel with the spacing x1. A spring 15 is inserted between the friction plate 13 and the brake pad 12 to maintain the above-mentioned interval x1. That is, the spring 15 generates a spring force in a direction separating the brake pad 12 and the friction plate 13.

By interposing the spring 15 in this way, the brake plate 11 and the brake pad 12 are pushed rightward in FIG.
It is positioned in close contact with the clutch plate 10.

FIGS. 5, 6, and 7 show an enlarged view of the brake device in the brake operating state, a cross-sectional view of a joint portion between the clutch plate 10 and the brake plate 11, and an enlarged front view of the joint portion, respectively. Two projections 16 projecting hemispherically at rotationally symmetrical positions obtained by dividing the circumference of the peripheral portion into two equal parts are integrally provided on the engagement surface portion of the clutch plate 10. On the other hand, in the engagement surface portion of the brake plate 11, four recesses 17 for receiving the projections 16 are provided at rotationally symmetrical positions corresponding to the projections and equally dividing the circumference by four. In the state of FIG. 4 where the brake is not actuated, the projection 16 fits into the recess 17 as shown in FIGS. 6 (1) and (3) and FIG. 7 (1). In the state of FIG. 5 in which the brake is operated, as shown in (2) of FIG. 6 and (2) of FIG. 7, the projection 16 jumps out of the concave portion 17 and is pressed against the flat portion of the brake plate 11.

When the brake is not operating and the brake plate 11 is in a free state, the pressure F
p results. Since the projection 16 and the recess 17 are fitted,
The clutch plate 10 and the brake plate 11 are in surface contact with each other, and the rotation of the clutch plate 10 is transmitted to the brake plate 11.

In this state, it is assumed that the clutch plate 10 is rapidly accelerated as the rotation speed of the scanner roller 3 increases. The spring force Fp is very small,
Since the fitting portion 11 is spherical and easily detaches, the projection 16 of the clutch plate 10 is separated from the concave portion 17. Thereby, the brake plate 11 moves in the X 'direction in FIG. At this time, by setting x2> x1, and by setting the clutch plate 10 and the brake plate 11 to be rigid and the brake pad 12 and the friction plate 13 to be elastic, the brake pad 12 and the friction plate 13 have x2> x1.
-X1 distortion occurs.

As a result, the rotation of the brake plate 11 is stopped by the friction between the brake pad 12 and the friction plate 13. In this state, the clutch plate 10 receives in the X direction the resultant force of the reaction force due to the strain of the brake pad and the force F′p when the spring 15 contracts x2. This force is transmitted to the platen via the gear and acts as a braking force.

Since the depressions 17 of the brake plate 11 are provided at intervals of θ = 90 ° as shown in FIGS. 6 (1) to 6 (3), the operation state of the brake is as follows. Works. Then, in the state of FIG. 6 (3), it returns to the free state by the spring force F'p.

[0022]

As described above in detail, according to the present invention, by applying a braking force to the scanner roller as the speed of the scanner roller becomes equal to or higher than a predetermined speed, the roller of the hand scanner can be appropriately adjusted. A load is applied. As a result, the scanning speed can be suppressed so as not to be higher than a certain rotation speed, and stable read data can be obtained.

In particular, according to the present invention, when the rotational speed of the scanner roller 3 increases and sudden acceleration occurs, the clutch plate 10
Of the brake plate 11 is disengaged from the recess 17 of the brake plate 11, whereby the elastic brake pad 12 and the elastic friction plate 13 are distorted and compressed, and a large frictional force is applied between the brake pad 12 and the friction plate 13. Occurs, and the brake plate 11,
Therefore, the rotation of the scanner roller 3 is stopped. Thus, without requiring an electrical configuration, reading can be performed with the rotation speed of the scanner roller 3 as high as possible within a range in which an image on the surface to be scanned can be read, thereby improving the performance of the hand scanner. It can be fully demonstrated.

Further, according to the present invention, the projection 16 formed on the clutch plate 10 has a spherical surface, so that when the rotation speed of the scanner roller 3 increases and sudden acceleration occurs,
The protrusion 16 can be immediately separated from the concave portion 17, thereby reliably preventing the reading of the image on the surface to be scanned from becoming impossible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an appearance of a configuration which is a premise of the present invention.

FIG. 2 is a front view showing the structure of the scanner roller 3 having the configuration shown in FIG.

FIG. 3 is a front view showing the structure of the scanner roller 3 according to one embodiment of the present invention.

FIG. 4 is an enlarged view showing a free state of the brake device in FIG. 3;

FIG. 5 is an enlarged view showing a brake operation state of the brake device in FIG.

FIG. 6 shows a clutch plate 10 and a brake plate 11 in FIG.
FIG. 4 is a cross-sectional view of a joint portion of FIG.

FIG. 7 shows a clutch plate 10 and a brake plate 11 in FIG.
FIG. 4 is an enlarged front view of a joint portion of FIG.

FIG. 8 is a front view showing a schematic structure of a conventional hand scanner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hand scanner 3 Scanner roller 5 Idler gear 6 Disk 7 Friction plate 9 Solenoid 10 Clutch plate 11 Brake plate 13 Friction plate 15 Compression spring

Claims (1)

(57) [Claims] A scanner roller is provided at a bottom portion of a casing so as to roll on a surface to be scanned by scanning, and a rotation speed of the scanner roller is controlled by a rotary encoder unit.
In a hand scanner that reads a document on a surface to be scanned in accordance with this speed, one end of the scanner roller 3 rotates integrally with the central axis of the scanner roller 3 and determines the axial direction of the central axis. A clutch plate 10 integrally formed with a projection 16 having a spherical surface protruding on the opposite side to the scanner roller 3 in the axial direction, and slidably in the axial direction on the central axis and rotating around the axis. A brake plate 11 which is non-rotatably fitted to the clutch plate 10 and has a concave portion 17 in which the projection 16 is removably fitted in the engagement surface portion on the clutch plate 10 side; A brake pad 12 adhered to the end face opposite to 10; a friction plate 13 made of an elastic body and fixed at a position parallel to and opposed to the brake pad 12; A spring 15 for generating a spring force in a direction separating the brake pad 12 and the friction plate 13 from each other, and the brake pad 12 and the friction plate 13 in a state where the projection 16 is fitted in the recess 17. The distance x1 is selected to be less than the projection amount X2 of the projection 16 in a state where the projection 16 is separated from the concave portion 17 and is in contact with the engagement surface portion.