JPH02288763A - Image scanner - Google Patents

Abstract

PURPOSE:To attain thin profile, small size and light weight by using a carrier means comprising a piezoelectric element causing a travelling wave in the travelling direction of an original to a carrier means. CONSTITUTION:A carrier means Y consists roughly of a vibrator element 18 comprising piezoelectric elements 11-13 and a ceramic member of the like, an AC generator 17, pressing rollers 9, 10 and a support base 19, and when the AC generator 17 applies a cos wave to the piezoelectric elements 11, 13 and a sin wave to the piezoelectric element 12, since the direction of polarization of the piezoelectric elements 11, 13 is opposite, the timing of the expansion contraction of the piezoelectric elements is retarded by 90 deg. each in the order of the piezoelectric elements 11, 12 and 13 and a travelling wave is caused from the left to the right in the vibrator element 18. Thus, the image scanner 1 is made thin in the profile.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a sheet φ-through φ type image scanner.

(Summary of the Invention) The image scanner of the present invention has a fixed image reading section and a sheet of paper that reads an original that is conveyed.
A through-type image scanner uses a conveying means made of a piezoelectric element that generates a traveling wave in the traveling direction of the document when conveying the document, and reduces the number of rollers or eliminates rollers by reducing the number of drive rollers for conveyance. It is characterized by being structured so that it can be achieved.

(Prior art and its problems) Conventional image scanners are handheld type (A), flat type, etc. as shown in Figure 5.
Bed type (B), sheet through type (C)
etc. They are divided according to their usage.

The hand-held scanner (A) has a small number of reading parts, and the scanner (A) is manually scanned to read images such as characters and figures drawn on a document.

Therefore, it is convenient for inputting image data only for a limited part of the area that you want to read, but since it is manual and only image data for a limited area can be input, it is difficult to input image data for a wide range of images such as A4 size. If you want to input image data, it is inconvenient and requires a large scanner (A) to accommodate it, making the machine itself very heavy, and inputting image data over a long straight distance. In some cases, it is difficult to input information in a uniform manner, resulting in extremely poor operability.

On the other hand, the flat bed type scanner (B) is a type in which the original is fixed and input, and is convenient for reading relatively large originals other than A4, but the device itself is large and requires heavy equipment. Therefore, it is not suitable when you want to use it on the disk side.

In addition, the sheet φ through type scanner (C) is
It is a type that reads by moving a reading sensor over a relatively large sheet-like document such as 4, and its characteristics are that it is suitable for reading relatively large documents over a wide range with good straightness; The product has the advantage of being smaller and lighter than the type scanner (B), but considering its use on the disk side,
As shown in the figure, since the drive roller 70 is required in the conveyance section, the thickness increases accordingly, and the area occupied including the document tray increases, and heavy parts such as the motor 72 that drives the drive roller 70 are required to carry it. The problem is that it is heavy due to its use, and as a result, there are restrictions on where it can be used.

Furthermore, as shown in FIG. 6, since the paper is fed by the frictional force between the drive roller 70 and the document paper It may not be possible to convey the material, or it may be necessary to use a large number of pressure rollers 71 to prevent this.
There were also problems with reading accuracy and space saving.

(Object of the Invention) The image scanner of the present invention has been made to solve the above-mentioned problems, and its purpose is to:
The sheet-through type image scanner, which moves and scans relatively large documents such as sheet-shaped A4 documents, has been made thinner, smaller, and lighter, making it more compact and more portable. At the same time, it is possible to improve reading accuracy by reliably feeding paper with little deterioration over time, and it is also possible to expand versatility by eliminating restrictions on where it can be used as much as possible.
There is a place that provides scanners.

(Structure and Effects of the Invention) In order to achieve the above object, the image scanner of the present invention includes a conveyance means for conveying a document for reading;
a detection mechanism that detects the distance that the original is being conveyed; and a detection sensor that irradiates light from a light source and reads information data written on the original when the original is detected by the detection mechanism. In the sheet-through type image scanner, the conveying means includes a piezoelectric element that generates a traveling wave in the traveling direction of the document.

The image scanner of the present invention having the above-described structure eliminates the need for a heavy motor by eliminating the driving roller and pressing roller from the conveyance means, and also achieves the labor savings of the driving roller and pressing roller. It is possible to achieve a compact size due to space saving and thinness and weight reduction.Moreover, since the structure does not require frictional force between the document paper and the drive roller, accurate images can be achieved by reliable document feeding without causing slipping phenomenon. The data is read, and overall it is possible to improve the reading accuracy and the versatility of the image scanner.

(Embodiment) An embodiment of the image scanner of the present invention will be described below with reference to the drawings.

Note that the same reference numerals are given to the same members shown in the conventional example, and the explanation thereof will be omitted.

1 to 6 show an embodiment of the image scanner of the present invention.

FIG. 1 is a block diagram showing an overall outline of the circuit configuration of an image scanner according to the present invention, and numeral 1 in the figure is a paper φ-through type image scanner.

As shown in the figure, this image scanner 1 reads an image drawn on a handwritten picture or drawing using an image sensor 50, and processes the image using a halftone processor circuit 51 serving as a binarization means and a CPU 52. Image input data is transferred to a host computer 60 such as a personal computer or word processor.
It is stored and accumulated in the internal memory and displayed on the display 60.
Displayed from a.

In addition, in the figure, 53 is an LED array as a light source that illuminates the surface of the document on which an image such as a picture is drawn.

54 is a rotary encoder for setting the image input range;
55 is a PIA circuit which is a control means for controlling the LED array 53 and the low-resolution encoder 54, 57 is a start switch, and 59 is a dip switch.

In addition, the PIA circuit 55, which is a control means, also controls the document paper
When it is transported close to, the transport control circuit 5 that drives the opening/closing lid control circuit 4 and the alternating current generating circuit 17 is driven and controlled by the human power signal from the photosensor 3 which is a detection means for detecting this. It is set.

Then, when the manuscript paper X is detected by the photo sensor 3,
The opening/closing lid control circuit 4 of the opening/closing lid 6 of the document insertion slot 2 is turned off by a command from the PIA circuit 55, the suction force by the electromagnet 7.7.8.8 is released, and the opening/closing lid is closed by a spring biasing means (not shown). 6 is automatically lifted upward by a predetermined width and held in an open state by a locking member such as a locking pawl. In this case, as the opening/closing means for the opening/closing lid 6, the opening/closing lid 6 may be automatically opened/closed by controlling the drive of a stepping motor or the like via a gear train or rope means, and in this example, the electromagnet 7 , 7°8.8.

In addition, 61 in the figure is an R3232C cable, and 62 is a D cable.
- RAM 63 is a program/ROM provided as a system Φ data compression means.

64 is an A/D shooting control circuit that manually adjusts the brightness of the image data, 65 is a RAM that stores the image data with adjusted brightness, and 66 is a line memory that stores image data for each line. be.

In addition, Figure 2 (a), (b) and Figure 3 (a), (
9, 10.9", and 10- shown in b) are pressure rollers or sliding protrusions for holding down the paper, and as shown in FIG. Press down to the extent that X does not bend.

In the figure, 14, 15, and 16 each indicate the polarization direction of the piezoelectric element.

That is, the conveyance means Y includes piezoelectric elements 11 to 13, a vibration element 18 made of a ceramic member, etc., and an AC generator 17.
The piezoelectric elements 11 to 13 are each coated with electrodes on the upper and lower surfaces thereof, and when an alternating current voltage is applied between the electrodes, the piezoelectric elements 11 to 13 move in the vertical direction. It is designed to expand and contract repeatedly.

14, 15, and 16 are the polarization directions of the respective piezoelectric elements 11 to 13, and if the polarization directions are reversed, the timing of expansion and contraction is also reversed.

Further, the vibrator 18 is made of a good conductor, and the holding table 19 is made of an insulator.

When the AC generator 17 applies a cosine wave to the piezoelectric elements 11 and 13 and a sine wave to the piezoelectric element 12, the piezoelectric element 1
Since the polarization directions of 1 and 13 are opposite, the timing of expansion and contraction of the piezoelectric elements is 9 in the order of piezoelectric elements 11, 12, and 13.
This results in a delay of 0 degrees, and a traveling wave is generated in the vibrator 18 from left to right. Then, the pressure roller 10 in contact with the vibrator 18 rotates clockwise.

Image session scanner 1 of the present invention configured as described above
The drive roller 70 and a large number of pressure rollers 7 are used as in the conventional case.
1 and a drive motor 72, etc., the image scanner 1 itself can be made thin as shown in FIG. By placing the image scanner 1 on the computer or disconnecting the R3232C connection, the image scanner 1 can be carried freely.

Also, a pressing roller, a driven protrusion 9. 10. 9.

Reference numeral 10' denotes a presser for preventing the original paper X from deflecting, and presses the original paper X between the pressing rollers 71, 71, . There is no need to utilize the document paper X, and mistakes in feeding the original paper X due to slippage are prevented, and image data can be read reliably, so that reading accuracy can be improved.

In addition, the image scanner 1 of the present invention has a structure in which the opening/closing cover 6 of the document insertion slot 2 is automatically opened when the document paper X is inserted, and is normally closed, so that document feeding is smooth. In addition to this, the intrusion of dust and the like can be prevented as much as possible when the image scanner 1 is not in use, and the inside of the image scanner 1 is protected.

As is clear from the above description, according to the invention of claim 1, the image scanner can be made thinner, smaller, lighter, and more compact, thereby improving portability. The piezoelectric element used also has little deterioration over time, and reading accuracy can be improved by constantly and reliably feeding the paper, and as a whole, improved reading accuracy and versatility can be achieved.

According to the second aspect of the invention, the document paper is transported smoothly, and the interior of the image scanner is sealed when not in use, preventing dust from entering from the outside. - Malfunction of the scanner is prevented and the inside of the image scanner is protected.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of the image scanner of the present invention, FIGS. 2(a) and 2(b) are perspective views and side views showing the operating state of the present invention, and FIG. 3(a) ,(
b) and 4 are side views showing the operating state of the piezoelectric element, 5 and 6 are perspective views showing the use of the image scanner of the present invention, and 7 and 4 are respectively side views showing the operating state of the piezoelectric element. 8(a) and 8(b) are a perspective view, a schematic side view, and a plan view, respectively, showing a conventional example. 1... Image-scanner 2... Document insertion slot (document insertion section) 3... Photo sensor (detection means) 4... Opening/closing lid control circuit 5... Conveyance means control circuit 6... Opening/closing lid 7.8...Electromagnet 9.10...Press roller 9-10''...Following projections 11-13...Piezoelectric elements 14-16...Electrode direction 17...AC generator 18... Vibrator 19... Holding stand 51... Image sensor, (detection means) 54...
Rotary encoder (distance detection means) X...Manuscript paper Y...Transportation means

Claims (1)

[Scope of Claims] 1. A conveyance means for conveying a document for reading, a detection mechanism for detecting the distance at which the document is conveyed, and when the document is detected by the detection mechanism, a means for conveying the document from a light source. In a sheet-through type image scanner that has a detection sensor that irradiates light and reads information data written on the document, the conveyance means includes a piezoelectric element that generates a traveling wave in the direction of travel of the document. An image scanner characterized by using a conveying means consisting of. 2. A document detection means that detects when the document approaches the conveying means; and a device connected to the detection means to open the document insertion section when the document approaches the document insertion section of the image scanner. The image scanner according to claim 1, further comprising an opening/closing mechanism.