JPH06209404A - Read mechanism - Google Patents

Abstract

PURPOSE:To obtain a read mechanism in which the read mechanism used for facsimile equipment, a copying machine and an image scanner is made thin and original feed and precise reading are executed. CONSTITUTION:A belt 8 is pressed to a read position 11 of a close contact image sensor 1 and an apex of a central projection 41 of a vibrator 4 is pressed into contact with the belt 8. When high frequency voltages whose phases are deviated by 90 deg. are applied to piezoelectric ceramics 51, 52, the apex of the central projection 41 of the vibrator 4 is set to an elliptic motion. The belt 8 is driven by a torque through a friction force by the elliptic motion and carries an original 3 in a subscanning direction and the original 3 is set between the close contact image sensor 1 and the belt 8. On the other hand, while a pattern 81 printed on the belt 8 is detected by a feed quantity sensor 9, a high frequency voltage is applied and the original is carried by one line and the close contact image sensor 1 reads a picture of the original 3 by one line. Precise reading is executed by alternately repeating the carrying of the original 3 and the reading.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading mechanism used in facsimiles, copying machines, image scanners and the like.

[0002]

2. Description of the Related Art As shown in FIG. 4, in a conventional reading mechanism, a pressing spring 12 of a contact image sensor 1 sets a reading position 11 of the contact image sensor 1 on a central portion 41 of a vibrator 4 via an original 3. When pressed, the contact image sensor 1 reads the image of the document 3. The vibrator 4 has a central portion 41 protruding in a convex shape, and the piezoelectric ceramic 51,
Reference numeral 52 is bonded to the vibrator 4 in a symmetrical position with the convex portion of the central portion 41 of the vibrator interposed therebetween. Piezoelectric ceramics 51, 5
A high frequency power source 6 applies high frequency voltages 2 to each other that are 90 degrees out of phase with each other. When a sine voltage having a phase difference of 90 degrees is applied to the piezoelectric ceramics 51 and 52, the apex of the vibrator central portion 41 makes an elliptic motion. Due to this elliptical movement, the original 3 in contact with the apex of the central portion 41 of the vibrator obtains a driving force via frictional force and is conveyed in the sub-scanning direction. The feed amount of the original 3 is the dummy roller 2 pressed by the original 3.
1, 23 and an encoder 23 connected to a dummy roller,
Detected by 24. The document 3 is conveyed at a speed of the vibrator 4
It depends on the size of the elliptic movement of the central portion 41 of the. In addition,
The size of the elliptical motion depends on the voltage. The original document 3 is fed while detecting the feed amount by the encoders 23 and 24, the feeding is stopped after advancing by one line, and the contact image sensor 1 reads. If the document 3 is conveyed and the contact image sensor 1 repeats the reading alternately, correct reading can be performed.

[0003]

In the above-mentioned conventional reading mechanism, the elliptic movement of the central portion of the vibrator is small, so that it is difficult to make the leading edge of the document bite between the vibrator and the contact image sensor. In order to bite the leading edge of the document, it is necessary to make the elliptic motion of the central portion of the vibrator larger than the thickness of the document, but this is technically impossible. Further, it is impossible to press the dummy roller to the reading position of the contact image sensor. Therefore, in order to read the entire length of the original, it is necessary to place two pairs of dummy rollers and encoders on the front and rear sides in the sub-scanning direction with the contact image sensor interposed therebetween, which has a disadvantage of requiring a large space.

[0004]

A reading mechanism according to the present invention comprises a contact type image sensor for reading an original by contacting it at a reading position, and a belt having a pattern pressed to the reading position of the contact type image sensor. ,
Position the belt and slide the belt 1
A pair of rollers, a feed amount detection sensor for reading the pattern of the belt, a vibrator having a convex central part, and a pair of piezoelectric ceramics bonded in symmetrical positions with the central convex part of the vibrator sandwiched therebetween. And a high frequency power source for applying a high frequency voltage with a 90 degree phase shift to the piezoelectric ceramic, and presses the apex of the central convex portion of the vibrator and the belt.

[0005]

The present invention will be described below with reference to the drawings. FIG. 1A is a sectional view of an embodiment of the present invention. The pressing spring 12 of the contact image sensor 1 presses the reading position 11 of the contact image sensor 1 against the belt 8. The pressing springs 42 and 43 press the central portion 41 of the vibrator 4 and the pressing block 44 via the belt 8. The vibrator 4 has a central portion 41 protruding in a convex shape, and the piezoelectric ceramics 51 and 52 are bonded to the vibrator 4 at a target position with the central portion 41 interposed therebetween. Piezoelectric ceramics 51, 52
Are applied with a high frequency voltage having a phase difference of 90 degrees from each other by a high frequency power supply 6. When a sine voltage having a phase difference of 90 degrees is applied to the piezoelectric ceramics 51 and 52, the apex of the central portion 41 of the vibrator 4 makes an elliptic motion. This exercise is shown in Figure 2.
This will be described with reference to FIG. When a voltage having a phase difference of 90 degrees as shown in FIG. 2 is applied to the piezoelectric ceramics 51 and 52, the vibrator 4 f11 to f14 and f21 to f21 to
Receives the force of f24. Therefore, at the time of t1, B direction,
At time t3, it is displaced in the C direction, and at time t4, it is displaced in the D direction to perform an elliptic motion. A similar motion can be obtained even if the voltage waveform is a sine wave, and a smooth elliptical motion is generated in the sine wave.
Due to this elliptic motion, the belt 8 in contact with the apex of the central portion 41 of the oscillator 4 obtains a driving force via frictional force and rotates in the E direction. At this time, the belt 8 is stably rotated in a fixed direction, and the original can be bited. Since the coefficient of friction between the belt 8 and the original 3 is set to be larger than the coefficient of friction between the paper guide 82 and the original 3, the original 3 is conveyed in the E direction by the thrust of the belt 8 via the frictional force. It

FIG. 1B is a perspective view of an embodiment of the present invention. A pattern 81 corresponding to the sub-scanning resolution is printed outside the reading width of the contact image sensor 1 in the sub-scanning direction of the belt 8 driven by the rollers 71 and 72.
The pattern 81 has a pitch of 1/7.
7 mm, or 1 / 3.85 mm, or 1 / 15.4 mm
The black and white pattern. The feed amount detection sensor 9 uses a reflective photo interrupter (not shown) to read the black and white of the pattern 81. The pattern 81 can be read by the feed amount detection sensor 9 to detect the feed amount of the belt 8. The feed amount of the original 3 is also detected corresponding to the feed amount of the belt 8. Here, while the feed amount detection sensor 9 detects the feed amount of the document 3, the high frequency power source 6 applies a sine voltage to the piezoelectric ceramics 51 and 52 to convey the document 3 for one line. 1 line manuscript 3
After the document is conveyed, the document is stopped and the image of the document 3 is read by the contact image sensor 1 for one line. Correct reading can be performed by alternately repeating the conveyance of the document 3 and the reading by the contact image sensor 1. The shape of the central portion 41 may be any shape such as a trapezoidal shape, an arc shape, an elliptical shape, or a sine wave shape, as long as it is easy to generate elliptical vibration. The height of the central portion 41 is 3 to 5 mm.
It can be achieved in a certain degree. Alternatively, the belt 8 may be a thin metal belt, the pattern 81 may be a slit, and the feed amount detection sensor 9 may be a transmissive photointerrupter. Further, as the feed amount detection function, a function incorporated in the end portion of the contact image sensor 1 may be used.

[0007]

As described above, according to the present invention, by combining the contact image sensor, the vibrator having the convex central part to which the piezoelectric ceramic is adhered, the belt, and the feed amount detection sensor, There is an effect that it is possible to provide a thin reading mechanism that can carry and read, and that does not require gears. Further, unlike the conventional example, since two pairs of dummy rollers and an encoder are not required, the size can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view (a) of an embodiment of the present invention and a perspective view (b) of the present embodiment.

FIG. 2 is a waveform explanatory diagram of the present embodiment.

FIG. 3 is an operation explanatory diagram of the present embodiment.

FIG. 4 is a sectional view of a conventional reading mechanism.

[Explanation of symbols]

 1 Contact image sensor 3 Original 4 Transducer 6 High frequency power supply 8 Belt 9 Feed length detection sensor 12, 42, 43 Pressing spring 41 Central part 44 Pressing block 51, 52 Piezoelectric ceramic 71, 72 Roller 81 pattern

Claims (2)

[Claims] 1. A contact type image sensor for reading a document in close contact at a reading position, a belt on which a pattern is pressed at the reading position of the contact type image sensor, the belt, and the belt. A pair of rollers that move, a feed amount detection sensor that reads the pattern of the belt, a vibrator having a convex central part, and a pair of adhesive bonded in a symmetrical position with the central convex part of the vibrator sandwiched therebetween. And a high-frequency power source that applies a high-frequency voltage with a 90-degree phase shift to the piezoelectric ceramic, and presses the apex of the central convex portion of the vibrator and the belt. 2. The reading mechanism according to claim 1, wherein the pattern printed on the belt forms a black and white pattern for reading the progress of the feed amount at a predetermined pitch length at right angles to the belt traveling direction. .