JPS63245061A - Image scanner - Google Patents

Abstract

PURPOSE:To contrive the reduction of the cost while eliminating the need for provision of a rotary encoder by detecting marks placed at a prescribed pitch driven by the rotation of a rotating and shifting means by means of a photo sensor. CONSTITUTION:For example, manual driving system is adopted for the driving system of mobile mechanism to drive rotating and shifting means 2a, 2b and an image scanner is moved in the subscanning direction, then the marks 11 of a prescribed pitch driven by the rotation of the driving means are detected by the photosensor 6 and a position detection signal in the subscanning direction is outputted. Then the position detection signal is given to a driving circuit controlling the read scanning as a timing signal of the read scanning and the read scanning of an electric signal by one line being the result of photoelectric conversion by a line type image sensor 5 is applied in the moving toward the subscanning direction. Thus, in adopting a DC motor or the manual drive as the driving source of the mobile mechanism, the provision of the rotary encoder is not required and the cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an image scanner used as an image information input device.

(Prior Art) Recently, as an image input device that can be relatively small and low-priced, a line-type image sensor and a line-type image sensor that moves in a direction perpendicular to the readout scanning direction, that is, in the sub-scanning direction, have been developed. An image scanner has been developed that is equipped with a moving mechanism that moves the image scanner to obtain image information by moving it flatly over the document. As a driving source for the above-mentioned moving mechanism, a stepping motor, a DC motor, or a manual method is considered.

In such an image scanner, it is necessary to appropriately set the readout scanning timing of one line's worth of electrical signals charged and converted by the line type image sensor and the movement timing in the sub-scanning direction by the moving mechanism. When a stepping motor is provided as a drive source for the movement IllI4, the timing and amount of movement in the sub-scanning direction by the movement mechanism are relatively accurately controlled by control signals from the control unit that performs the readout scan 54ii.

However, one purpose of this type of image scanner is to reduce the cost, and as a driving source for the moving mechanism, a stepping motor, which is relatively expensive, is avoided.
A D-C motor or manual type is desired.

However, in the case where a DC motor or manual means is used as the driving source, as in the case of the stepping motor type described above, the movement timing in the sub-scanning direction and That move! It is difficult to control Ht accurately.

Therefore, when a D-C motor or manual means is adopted as the drive source of the moving mechanism, a rotary encoder is incorporated into the moving mechanism, and the itqm section side that reads the position detection signal obtained from the rotary encoder and controls scanning. Therefore, it is necessary to adopt a timing control method in which reading scanning for one line is performed while movement in the sub-scanning direction is being performed.

(Problems to be solved by the invention) However, in order to reduce costs, it is necessary to install a relatively expensive rotary encoder even though a D-C motor or manual means is adopted as a drive source for the moving mechanism. However, there was a problem in that it was not possible to sufficiently reduce costs.

The present invention has been made based on the above circumstances, and provides an image scanner that can reduce costs by eliminating the need for a rotary encoder when a DC motor or manual means is adopted as the drive source of the moving mechanism. The purpose is to

[Structure 1 of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides an illumination means for illuminating a document, and converting an image of the document illuminated by the illumination means into an electrical signal. a line-type image sensor that moves over the document in a direction perpendicular to a reading scanning direction of the converted electric signal in the line-type image sensor; and a rotational movement means that rotates in accordance with the rotation of the rotational movement means. The gist of the present invention is to include a photosensor that detects marks at a predetermined pitch and outputs a position detection signal that serves as a timing signal for readout scanning of the line-type image sensor.

(Function) When the drive method of the movement #1 mechanism is, for example, a manual operation type, and the rotational movement means is driven and the image scanner is moved in the sub-scanning direction, a predetermined pitch that rotates according to the rotation of this rotational movement means is set. mark is detected by the photo sensor,
A position detection signal in the sub-scanning direction, in other words, a signal indicating the scanning density in the #1 scanning direction is output. This position detection signal is then given as a timing signal for the readout scan to the drive circuit side that performs the readout scan.
During movement in the sub-scanning direction, one line of electrical signals photoelectrically converted by the line-type image sensor is read out and scanned. Since the photosensor can be formed simultaneously in the manufacturing process of the line type image sensor, cost reduction is achieved.

(Example) Hereinafter, an example of the present invention will be described based on FIGS. 1 to 5. This embodiment is applied to a hand scanning type (manual type) image scanner.

First, the configuration of the image scanner will be described. As shown in FIG. 2, the image scanner 10 obtains image information by hand scanning a document 12 in the sub-scanning direction. As shown in FIG. 1, an O-ra 2a is mounted on the lower surface of the box 1 as a rotational movement means in the sub-scanning direction.
2b are attached at a required interval, and two rows of LED arrays 3 as illumination means for illuminating the original 12 are arranged in the frontage of the two rollers 2a and 2b11.

A rod lens array 4 for condensing light is erected at the center of the LεD7 rays 3 arranged in two rows.
A line type image sensor 5 is arranged on the back side of the screen.

Further, drive O-roughs a and 7b are fixed to the ends of the rotating shafts of the rollers 2a and 2b, respectively, and the drive rollers 7a and
A belt 9 is passed between the roller 17b and the driven rollers 8a and 8b. As shown in FIG. 4, a film on which marks 11 are printed at a predetermined pitch corresponding to the sub-scanning density is attached to the inner surface of the belt 9. A seven-dimensional sensor 6 for detecting the mark 11 is formed on an extension of the line image sensor 5 at an appropriate distance from the line image sensor 5. The photosensor 6 is formed at the same time as the line image sensor 5 is manufactured.

FIG. 5 shows a control circuit for reading and scanning electrical signals as image data detected by the line image sensor 5. In the figure, 13 is a control section, and 14 is the line image sensor 5. The driving circuit 15 is a position detection signal (sub-scanning speed signal) generating means constituted by the photosensor 6 and the mark 11 provided on the belt 9.

Next, the effect will be explained.

The LED array 3 is turned on, and the image scanner 10
When the original 12 is hand-scanned in the sub-scanning direction at a predetermined speed, the original image is converted into an electrical signal by the line image sensor 5.

At the same time, the mark 11 rotating at a speed corresponding to the moving speed in the sub-scanning direction is detected by the photosensor 6, and the photosensor 6 outputs a position detection signal in the sub-scanning direction, in other words, a position detection signal in the sub-scanning direction. A signal indicating the scanning density is output. Then, the drive circuit 14 is driven by this signal,
While the image scanner 10 moves by a predetermined pitch in the u1 scanning direction, one line of image data photoelectrically converted by the line type image sensor 5 is read out and scanned,
The information is taken into the control unit 13.

In this way, the original 1if by the line image sensor 5
The conversion of the image data to one line of image data, the movement of the image scanner 10 by a predetermined pitch in the sub-scanning direction, and the reading scan of one line of image data during the movement by this predetermined pitch are sequentially repeated. , the two-dimensional image data is 1. II Ogoribe 13 is incorporated.

[Effects of the Invention] As explained above, according to the present invention, marks at a predetermined pitch that rotate in accordance with the rotation of the rotary moving means can be formed using a photosensor that can be formed simultaneously in the manufacturing process of a line-type image sensor. By detecting the position, it is possible to obtain a position detection signal that is the timing signal for readout scanning of the line image sensor. There is an advantage that an encoder is not required and costs can be reduced.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1 to 5 show an embodiment of the image scanner according to the present invention. FIG. The figure is a side view, FIG. 3 is a plan view showing a line type image sensor and a photosensor portion, and FIG. 4 is a plan view showing a mark portion at a predetermined pitch.
FIG. 5 is a block diagram showing a control circuit for reading and scanning a line type image sensor. 2a, 2b: Roller (@Rotating means), 3: LED array (illumination means), 4: Rod lens array, 5 Two-line image sensor, 6: Photo sensor, 9: Belt, 11: Mark at specified pitch, 12 :Manuscript.

Claims (1)

[Claims] an illumination means for illuminating a document; a line-type image sensor for converting an image of the document illuminated by the illumination means into an electrical signal; and a reading scanning direction of the converted electric signal in the line-type image sensor over the document. A rotational movement means for moving in orthogonal directions and a mark at a predetermined pitch that rotates in accordance with the rotation of the rotational movement means are detected and a position detection signal is outputted as a timing signal for readout scanning of the line image sensor. An image scanner comprising a photosensor.