JP2845021B2 - Reading mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading mechanism,
In particular, it relates to a reading mechanism used in a facsimile, a copying machine, an image scanner, and the like.

[0002]

2. Description of the Related Art A conventional reading mechanism will be described with reference to the drawings.

FIG. 4 is a sectional view of a conventional reading mechanism. The reading roller 2 is pressed against the reading position 11 of the contact type image sensor 1. The reading roller 2 is connected to a motor 5 by a driving system 4 such as a gear train. When the motor 5 rotates, the reading roller 2 also rotates and conveys the document 3 in the sub-scanning direction. At this time, if the rotation speed of the motor 5 is synchronized with the reading speed of the photoelectric conversion unit of the contact type image sensor 1, the image of the document can be read.

[0004]

However, as described above, the conventional reading mechanism has a problem that a large space is required in order to convey a document by rotating a roller using a driving system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and an object of the present invention is to provide a novel reading mechanism capable of solving the above-mentioned problems inherent in the prior art. It is in.

[0006]

To achieve the above object, a reading mechanism according to the present invention comprises: a plurality of photoelectric conversion units arranged in a main scanning direction; a light source for irradiating a document surface;
A contact type image sensor comprising a photoelectric conversion unit and a driving base for driving the light source, the original being brought into close contact with a reading position, and reading the closely attached original; A transducer formed to be approximately the same length as the reading width of the piezoelectric transducer, a piezoelectric ceramic bonded to a target position with a central convex portion of the transducer sandwiched,
A high-frequency power source for applying a high-frequency voltage having a phase shift of 90 degrees to these piezoelectric ceramics is provided, and the apex of the central convex portion of the vibrator is located at the reading position of the contact image sensor.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a preferred embodiment of the present invention.

FIG. 1 is a sectional view showing an embodiment of the present invention.

Referring to FIG. 1, a contact image sensor 1 reads an image of a document 3 which is brought into close contact with a reading position 11. The vibrator 6 has a central portion 61 formed so as to protrude in a convex shape, and has a length in the main scanning direction in the contact type image sensor 1.
And the length is substantially the same as the reading width. The piezoelectric ceramics 71 and 72 are bonded to the vibrator at symmetric positions with respect to the vibrator center convex portion 61. The piezoelectric ceramic 7
The high-frequency power supplies 8 are applied with high-frequency voltages having phases shifted by 90 degrees from each other.

If the vibrator 6 is placed so that the apex of the central convex portion 61 coincides with the reading position 11 of the contact image sensor 1, the image of the original 3 sandwiched between the vibrator 6 and the contact image sensor 1 can be obtained. Can be read.

At this time, when a sine voltage having a phase shift of 90 degrees is applied to the piezoelectric ceramics 71 and 72, the apex of the central portion 61 of the vibrator performs an elliptical motion. This movement will be described with reference to the drawings.

As shown in FIG. 2, when a voltage having a phase shift of 90 degrees is applied to the piezoelectric ceramics 71 and 72, the vibrator 6 has f11 to f14 and f21 to f21 as shown in FIG.
Receive 24 forces. For this reason, at time t1, it is compressed from both sides and the vertex of the vibrator center part 61 is displaced in the A direction. Similarly, it is displaced in the B direction at time t2, in the C direction at time t3, and in the D direction at time t4, and performs an elliptic motion. A similar motion can be obtained with a sine wave for the voltage waveform, and a smoother elliptical motion occurs with the sine wave. Due to this elliptical motion, the original 3 in contact with the vertex of the vibrator center 61 obtains a driving force via frictional force and is conveyed in the E direction.

The speed at which the document 3 is conveyed depends on the magnitude of the elliptical motion of the vibrator center 61, and the magnitude of the elliptical motion depends on the voltage. Therefore, correct reading can be performed by adjusting the voltage so that the conveyance speed of the document 3 is synchronized with the reading speed of the contact image sensor 1.

The shape of the center portion 61 of the vibrator may be any shape such as a trapezoid, an arc, an ellipse, and a sine wave, as long as the ellipse vibration is easily generated. Also, the vibrator center portion 61
Can be realized with a height of about 3 to 5 mm.

[0015]

As described above, according to the present invention,
By combining a contact type image sensor and a vibrator with a convex center at the center where the piezoelectric ceramic is bonded,
A reading mechanism capable of carrying and reading a paper can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a high-frequency voltage waveform applied to a piezoelectric ceramic according to the present invention.

FIG. 3 is a diagram showing a motion of the vibrator of FIG. 1;

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Contact image sensor 11 ... Reading position 2 ... Roller 3 ... Document 4 ... Deceleration mechanism 5 ... Motor 6 ... Vibrator 61 ... Vibrator center 71 ... Piezo ceramic 72 ... Piezo ceramic 8 ... High frequency power supply

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor: Osamu Meika Inside NEC Corporation 5-7-1 Shiba, Minato-ku, Tokyo (56) References JP-A-5-328060 (JP, A) JP-A Heisei 5-160970 (JP, A) JP-A-5-278889 (JP, A) JP-A-2-288873 (JP, A) JP-A-1-313232 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04N 1/04-1/207

Claims (2)

(57) [Claims] A plurality of photoelectric conversion units arranged in a main scanning direction, a light source for irradiating an original surface, a driving base for driving the photoelectric conversion unit and the light source, and bringing the original into close contact at a reading position; A contact-type image sensor for reading a closely adhered document; a vibrator having a central portion formed in a convex shape and having a length substantially equal to the reading width of the contact-type image sensor; and a central convex portion of the vibrator. And a piezoelectric ceramic bonded in a symmetrical position with
A reading mechanism, comprising: a high-frequency power supply for applying a high-frequency voltage having a phase shift of 0 degrees, wherein a vertex of a center convex portion of the vibrator is positioned at a reading position of the contact image sensor. 2. The reading mechanism according to claim 1, further comprising: adjusting the high-frequency voltage so that a conveying speed of the document is synchronized with a reading speed of the contact image sensor.