JPS6359160A - Handy type image scanner - Google Patents

Abstract

PURPOSE:To uniformize the read image density by detecting the speed of a scanner to an original scanning direction so as to vary the scanning drive timing of a sensor. CONSTITUTION:The original 12 is moved in a speed (v=l/t; l is original relative movement per time t) relatively by the movement of the scanner 1, a roller 5 is turned by an angular velocity in response to the original relative moving speed and an encoder 2 is turned at an angular velocity accordingly. Dark/light slits formed around the encoder 2 are detected by a photodetector 41 and a pulse is generated in the timing in response to the angular velocity of the encoder, that is, the scanning speed of the original. Since the scanning drive timing of the sensor is variable in this way, the image of the original is reproduced with fidelity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a handheld image scanner that reads images such as characters, zeros, figures, graphs, and the like.

[Conventional technology]

Conventionally, image scanners are used in copiers, facsimile machines, electronic whiteboards, various image readers, etc., and are either of the type where the AC is fixed on the sensor unit side, which consists of a sensor, lens, light source, etc., and the document side is automatically fed, or where the document side is fixed. There is a type that moves the sensor unit (y) side, but in any case, the entire device is fixed, and originals such as documents must be set on the document table. There is a need to set up the manuscript.

[Problem that the invention seeks to solve]

Recently, word processor, electronic 7-eye ring system.

Use an electronic editing device to input partial text, figures, graphs, etc., edit them, and then print them out.

7. A machine for filing and transferring is required. Therefore, with a conventional fixed scanner, it is necessary to prepare a document, which is troublesome. For example, from a part of a newspaper, and fragile from a part of a magazine.

It would be very convenient to have an image input device (b) that can freely and conveniently read images from parts of posters, etc. When making cards or postcards using a word processor, etc., it would be very convenient to have a device that allows you to input partial pictures.

However, when hand-held scanners are moved manually, the scanning speed of the scanner in the document scanning direction cannot be kept constant, and this causes the problem of non-uniform image density.

The present invention solves these problems.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention detects, for example, the speed i of the scanner in the document scanning direction, and changes the scan drive timing of the sensor based on the detected data, so that the scanned image can be read. Equalize density.

[Effect]

If the above-mentioned measures increase the speed of the scanner in the document scanning direction, for example, the data pulse from the speed detection means can be used to speed up the scanning drive timing pulse of the sensor using, for example, a PLL (phase lock loop). Conversely, if the speed of the scanner in the document scanning direction becomes slow, the scan drive timing pulse of the sensor is slowed down. By doing this, the scanning resolution can be made uniform in both the main scanning and sub-scanning directions, and the problem of non-uniform density of read images can be solved.

〔Example〕

FIG. 1 is a schematic cross-sectional view of an image scanner according to an embodiment of the present invention, in which 1 is a scanner housing, which includes a system control circuit, an image frame memory, an image data output interface, a reflection mirror 10, an image sensor 9, and a cell. Focklen, (8, center of rotation axis supported by the housing 6.6
A cylindrical roller 51 that rotates around the center and is long in the direction perpendicular to the paper surface; an LED (light emitting diode array) 7 as a light source that efficiently illuminates originals such as documents using a reflecting mirror; The roller 4 rotates around 3.3 by contact with the roller 5, and the encoder 2 as a speed detection means rotates around 3 so that the rotation angle is the same as that of the roller 4.

This is the scanning direction of the scanner with respect to the document 12 in the direction perpendicular to the paper surface. LED, -1! The Le7oc lens, image sensor, and reflection mirror are all set long inside the housing in a direction perpendicular to the plane of the paper. Therefore, the scanning drive direction of the image sensor is perpendicular to the abrasive surface. The rollers 5 are arranged at the four corners of the housing, similar to the positions of automobile tires. This configuration is not necessarily necessary, and if the space h of the encoder 2 can be secured, the roller 5 on the right side of the drawing may be integrated in the direction perpendicular to the plane of the paper.

FIG. 2 shows an example 21 of the image sensor section used in the present invention, in which the sensor scan drive circuit has a 22-digit shift register configuration, and the 22-digit scan start timing is controlled by a 23-digit start pulse input fi device, every one line scan. is input. 24
and 25 are input terminals for a clock and its inverted clock that control the scan drive timing in the shift register and the ON and OFI timings of the switch 50, respectively.

26 power supply terminals, 27 data output terminal and amplifier.

It passes through an integrator 28 and becomes an analog signal. These are a switch that controls a 29-digit integrator, a 31-digit photodiode, and a 32-digit capacitor. This is an output terminal for an end pulse indicating the end of 33-digit one-line scanning.

FIG. 3 is a multiple block diagram of an embodiment of the present invention, in which the system control section 36 includes R, OM, RAM, CPU, and other logic circuits. The analog output from the 37 sensors 21 is converted into digital. The digital data, which has been binarized or multi-valued, is transferred to the frame memory 38, and image data is outputted via a suitable interface. There are 40 control path lines that supply control signals for each device and take in speed detection data from the Aiike detector.

FIG. 4 is the next diagram illustrating the key points of the present invention. Due to the movement of the scanner 1, the original 12 moves at a relative speed υ = t/l (t is the amount of relative movement of the original per 6 hours), and the roller 5Fi rotates at an angular velocity according to the relative movement speed of the original. .

Accordingly, the encoder 2 also rotates at a certain angular velocity. A bright and dark slit formed around the encoder 2 is detected by an optical detector 41, and pulses are generated at a timing corresponding to the angular velocity of the second encoder, that is, the scanning speed of the document. A portion 77 in the drawing is a portion where circuits such as pulse shaping are omitted. , 42, the so-called PLL part, the clock from 24' is 8 times the clock frequency of 48.

23' is input to the terminal 23 of the image sensor section, and 2a
'hz Also, the inverted clock of terminal 24.24 is terminal 2
5 is input. Therefore, the number of bits per line of the sensor is approximately N.

In this embodiment, an encoder and an optical detector are used as means for detecting the speed of the scanner in the document scanning direction, but other means such as a magnetic encoder may be used.

Roller 5 is used to prevent the scanner from meandering. It is clear that another child actor could be hired for this as well.

〔Effect of the invention〕

As described above, according to the present invention, the inconvenient problems associated with hand-held scanners can be solved.

That is, when the scanning drive timing of the sensor is always constant, the analog output from the sensor becomes smaller as the scanning speed of the scanner with respect to the document becomes faster, and vice versa. Therefore, in the case of the edge of the brush, the image density is smaller in the former case and larger in the latter, so that when printing out, etc., the output image becomes lighter and darker at the edge of the brush than the original document. In the present invention, since the scanning drive timing hi of the sensor is variable, the image of the original original can be faithfully reproduced. Therefore, the warp c1. ! li collection device, 7
6 is expected to be applied to eye ring devices, etc.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a mechanism of an embodiment of the present invention. FIG. 2 is a circuit diagram of a configuration example of an image sensor adopted in an embodiment of the present invention. FIG. 3 is a general system configuration block diagram of an embodiment of the present invention; FIG. 4 is a detailed schematic block diagram for explaining the present invention. Figure 1 Figure 2

Claims (1)

[Claims] In a handheld image scanner that is composed of at least an image sensor, a light source, a lens, etc. and scans images such as characters, figures, graphs, etc. of documents, the speed of the image scanner in the document scanning direction of the documents, etc. is detected. 1. A handheld image scanner comprising means for changing the scan drive timing of the sensor based on data from the detection means.