JPH06209403A - Read mechanism - Google Patents

Abstract

PURPOSE:To obtain a read mechanism in which a vibrator of the read mechanism used for facsimile equipment, a copying machine and an image scanner is made thin and paper feed and read of a feed quantity are executed correctly. CONSTITUTION:A feed roller 2 is pressed to a read position 11 of a close contact image sensor 1, a feed quantity detection pattern 22 is pressed to a photoelectric conversion section 12 at the outside of a read width and an apex of a central projection 61 of a vibrator 6 is pressed into contact with a feed roller shaft 21. When high frequency voltages whose phases are deviated by 90 deg. are applied to piezoelectric ceramics 71, 72 bonded to the vibrator 6 respectively, the apex of the central projection 61 of the vibrator 6 is set to an elliptic motion. The roller shaft 22 is driven by a torque through a friction force by the elliptic motion and carries an original 3 in a subscanning direction. Furthermore, when a photoelectric conversion section 12 at the outside of a read width detects a feed quantity detection pattern 22, a voltage by a high frequency power supply 8 is stopped to stop carrying of the original 3 and reading is executed. The reading of the close contact image sensor 1 and the carrying of the original 3 are synchronized by repeating the processing above to execute 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 Conventionally, a reading mechanism of this type is shown in FIG.
The reading mechanism shown in the conventional example of FIG. 5, the second conventional example of FIG. 5, and the third conventional example of FIG. 6 is known. FIG. 4 is a cross-sectional view of the first conventional example. The reading roller 2 is pressed against the reading position 11 of the contact image sensor 1. The reading roller 2 is connected to a motor 5 by a drive system 4 such as a gear train. When the motor 5 rotates, the reading roller 2 also rotates, and the original 3 is conveyed in the sub scanning direction. At this time, the motor 5
The image of the original can be read by synchronizing the rotation speed of the with the reading speed of the photoelectric conversion unit of the contact image sensor 1. However, such a reading mechanism
A large space is required in order to rotate the roller 2 using a drive system and convey the document.

In order to solve this, a reading mechanism using the piezoelectric vibrator of the second conventional example can be considered. FIG. 5 of the second conventional example is a sectional view and a perspective view of a reading mechanism using a piezoelectric vibrator. In FIG. 5A, the pressing spring 91 of the contact image sensor 1 presses the feed roller 2 to the reading position 11 of the contact image sensor 1 via the document 3. Contact image sensor 1 is original 3
Read the image. The vibrator pressing spring 92 presses the roller shaft 21 of the feed roller 2 and the top of the central portion 61 of the vibrator 6. The vibrator 6 has a central portion 61 protruding in a convex shape, and the piezoelectric ceramics 71 and 72 are bonded to the vibrator at a target position with the vibrator central convex portion 61 interposed therebetween.
FIG. 5B is a perspective view of the second conventional example, in which the piezoelectric ceramics 71 and 72 are applied with a high frequency voltage having a phase difference of 90 degrees from each other by the high frequency power source 8. Piezoelectric ceramic 7
When sine voltages having a phase difference of 90 degrees from each other are applied to 1 and 72, the apex of the oscillator central portion 61 performs an elliptic motion. Due to this elliptic motion, the roller shaft 21 for feeding, which is in contact with the apex of the vibrator central portion 61, obtains a driving force via frictional force, and E
Rotate in the direction. The feed roller 2 is rotated by a vibrator 6 via a roller shaft 21. The original 3 is conveyed in the sub-scanning direction by the rotation of the feed roller 2. The conveyance speed of the document 3 depends on the rotation speed of the feed roller 2. The rotation speed of the feed roller 2 depends on the size of the elliptical motion of the vibrator central portion 61, and the size of the elliptical motion depends on the voltage. Therefore, the voltage is adjusted so that the feeding speed of the original 3 is synchronized with the reading speed of the contact image sensor 1, so that the correct reading is performed.

[0004]

In the conventional reading mechanism as described above, since the rotation of the roller shaft is obtained from the vibrator through friction, the contact state between them, that is, the surface state,
There is a drawback in that the rotational speed changes due to the change in the friction coefficient due to the pressing force, changes over time, etc., and the reading speed cannot be synchronized.

[0005]

A reading mechanism according to the present invention comprises a plurality of photoelectric conversion units arranged in the main scanning direction, a light source for illuminating an original surface, a drive base for driving the photoelectric conversion units and the light source. A close contact type image sensor is provided which is in close contact with the original at the reading position and is also provided outside the reading width of the original in the main scanning direction, and the original reading width of the close contact type image sensor is pressed to the reading position of the close contact type image sensor. A reading roller provided with a feed amount detection pattern on the portion pressed by the outer photoelectric conversion unit, a vibrator with a convex central part, and a central convex part of this vibrator sandwiched between them and bonded to the target position. The piezoelectric ceramic, a high frequency power source for applying a high frequency voltage with a 90 ° phase shift to the piezoelectric ceramic, and the apex of the central convex portion of the vibrator and the shaft of the reading roller are pressed.

[0006]

The present invention will be described below with reference to the drawings. 1A is a perspective view of an embodiment of the present invention, FIG.
(B) is a view in the direction of the arrow F of the present embodiment. In FIG. 1, the pressing spring 91 of the contact image sensor presses the feed roller 2 through the document 3 to the reading position 11 of the contact image sensor 1. The contact image sensor 1 reads the image of the document 3. The contact image sensor 1 also has a photoelectric conversion unit 12 and a light source in a portion outside the original reading width. The feed roller 2 has a position outside the original reading width of the contact image sensor 1 with respect to the photoelectric conversion unit 12,
A feed amount detection pattern 22 is provided. The feed amount detection pattern 22 is a black-and-white pattern in which the pitch matches the resolution of one sub-scanning line, and in the case of a facsimile, for example, 1 / 15.4 mm, 1 / 7.7 mm, 1 / 3.85.
Provided at a pitch of mm or the like. The photoelectric conversion unit 12 outside the original reading width of the contact image sensor 1 reads the feed amount detection pattern 22 of the roller 2. Oscillator pressure spring 9
2 presses the roller shaft 21 of the feed roller 2 and the top of the central portion 61 of the vibrator 6. The vibrator 6 has a central portion 61 protruding in a convex shape, and the piezoelectric ceramics 71, 72
Is bonded to the vibrator at a target position with the vibrator central convex portion 61 sandwiched therebetween. The piezoelectric ceramics 71 and 72 are applied with a high frequency voltage having a phase difference of 90 degrees from each other by a high frequency power source 8. When a sine voltage having a phase difference of 90 degrees is applied to the piezoelectric ceramics 71 and 72, the apex of the vibrator central portion 61 makes an elliptic motion.

This movement will be described with reference to the drawings. Figure 2
When a voltage with a phase difference of 90 degrees is applied to the piezoelectric ceramics 71 and 72 as shown in (a), the vibrator 6 receives forces f11 to f14 and f21 to f24 as shown in FIG. 2B. Therefore, at t1, the vertices of the oscillator central portion 61 are compressed from both sides and are displaced in the A direction. Similarly, an elliptic movement is performed by displacing in the B direction at t2, the C direction at t3, and the D direction at t4. As for the voltage waveform, a similar motion is obtained even with a sine wave, and a smooth elliptical motion occurs with the sine wave. Returning to FIG. 1, this elliptic motion causes the feed roller shaft 21 in contact with the apex of the central portion 61 of the vibrator to obtain a driving force via a frictional force and rotate in the E direction. The feed roller 2 is rotated by a vibrator 6 via a roller shaft 21. The original 3 is rotated by the feed roller 2
It is conveyed in the sub-scanning direction. At this time, the reading and the conveyance of the original 3 are synchronized by the feed amount detection pattern 22 of the feed roller 2 read by the photoelectric conversion unit 12 outside the original reading width of the contact image sensor 1.

FIG. 3 is a flow chart showing a control method for establishing synchronization. Piezoelectric ceramic 71,
When a sine voltage having a phase difference of 90 degrees from each other is applied to 72 to vibrate the vibrator 6, the roller 2 rotates and the original 3 is conveyed. When the roller 2 rotates by one line, the photoelectric conversion portion 12 outside the original reading width of the contact image sensor 1
Reads the feed amount detection pattern 22 of the roller 2. At this point, the sine voltage of the high frequency power source 8 is turned off, and the rotation of the roller 2 is stopped. Then, the contact image sensor 1 reads the original 3 for one line. When the reading is completed, the high frequency power source 8 is used again to piezoceramic 7
Applying sinusoidal voltages 90 degrees out of phase with each other to 1,72,
The roller 2 is rotated until the photoelectric conversion portion 12 outside the original reading width of the contact image sensor 1 reads the next feed amount detection pattern 22. If this is repeated, the document feed amount until the end of one page and the reading can be synchronized, and accurate reading can be performed. Transducer central part 6
The shape of 1 may be any shape such as a trapezoid, an arc shape, an ellipse shape, a sine wave shape, as long as it easily causes elliptical vibration. Further, the height of the vibrator central portion 61 can be realized by about 3 to 5 mm.

[0009]

As described above, according to the present invention, a contact image sensor having a photoelectric conversion portion and a light source outside the original reading width, and a feed amount to a position outside the original reading width with respect to the photoelectric conversion portion. By combining a reading roller with a detection pattern and a vibrator with a convex center bonded to a piezoelectric ceramic, it is possible to convey and read paper that is thin and does not require gears. This is effective in providing a reading mechanism capable of performing accurate reading regardless of the contact state of the child.

[Brief description of drawings]

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

FIG. 2 is a high frequency voltage waveform diagram (a) and an operation explanatory diagram (b) of the present embodiment.

FIG. 3 is a flowchart of this embodiment.

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

FIG. 5 is a sectional view (a) of a reading mechanism of a second conventional example.
It is a perspective view (b).

[Explanation of symbols]

 1 Contact image sensor 2 Roller 3 Original 4 Deceleration mechanism 5 Motor 6 Vibrator 8 High frequency power source 11 Reading position 12 Photoelectric conversion part 21 Feed roller 22 Feed amount detection pattern 61 Center part 71,72 Piezoelectric ceramic 91,92 Pressing spring

Claims (2)

[Claims] 1. A plurality of photoelectric conversion units arranged in the main scanning direction, a light source for illuminating a document surface, a drive base for driving the photoelectric conversion unit and the light source, and a document in close contact with each other at a reading position. And a contact type image sensor also provided outside the reading width of the document, and a portion pressed to the reading position of the contact image sensor and pressed to the photoelectric conversion portion outside the reading width of the document of the contact type image sensor. A reading roller with a feed amount detection pattern on the
A vibrator with a convex central part, a piezoelectric ceramic that is bonded to the target position by sandwiching the central convex part of the vibrator, and a high-frequency power source that applies a high-frequency voltage that is 90 degrees out of phase to the piezoelectric ceramic. A reading mechanism characterized in that a vertex of a central convex portion of the vibrator and a shaft of the reading roller are pressed. 2. The paper is conveyed and the feed amount is detected by combining the piezoelectric ceramics with a vibrator having a convex center portion to form a thin paper.
The reading mechanism described.