JPS5937769A - Figure reader - Google Patents

Abstract

PURPOSE:To prevent a decrease in resolution in a subscan direction, by turning on a lamp for original illumination only for a short time synchronously with the read period of a solid-state image sensor. CONSTITUTION:The lamp 1 for illuminating an original 8 is turned on for a short time synchronously with the read period of a solid-state image sensor 3 having a unidimensional array for reading, and reducing the movement of the original 8. Namely, data OS on one picture element is read out by one driving clock signal phiR of the sensor 3. A light emission control signal phiL is delayed synchronously a specific time behind a one-line read synchronizing signal phiTG and used for on-off control over a fluorescent lamp 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image reading device that reads images such as figures, text, etc. and converts brightness information of the images into electrical signals.

A one-dimensional solid-state image sensor has traditionally been used as a typical means of reading figures and images. An example of an image reading device using a solid state image sensor is shown in FIGS. 1 and 2. FIG. FIG. 1 is a perspective view of a conventional device, and FIG. 2 is a side view thereof.

In the figure, 1 is a fluorescent lamp (lamp) for illuminating the original 8;
2 transfers the image of the original 8 to a one-dimensional array of solid-state
Image sensor (abbreviated as Itcho image sensor) 3
4 is a reflecting mirror. A document 8 is illuminated by a fluorescent lamp 1 and imaged by an imaging lens 2 onto an image sensor 3. Incidentally, reference numeral 9 is a row 2 for feeding the original, which drives the original 8 at a constant speed.

Since the reading speed of conventional devices was slow, a document drive method was used that sequentially moved the document line by line. However, as the reading speed increases, it is becoming difficult to move the original line by line at a high speed. Furthermore, when inputting a large original such as a book, it is still difficult to sequentially feed the original υ. Therefore, when reading an original at high speed or when reading an original with a large mass such as a book, a method of feeding the original at a constant speed can be considered.

In conventional apparatuses, when a document is fed at a constant speed, a drawback arises in that the resolution in the sub-scanning direction (original feeding direction) is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus that prevents a decrease in resolution in the sub-scanning direction when a document is fed at a constant speed, and reads a document at high speed and a document having a large mass such as a book.

When a document moving at a constant speed is read using a conventional device,
During the reading period, one digit moves, resulting in blurring of the digits and a decrease in resolution. Therefore, the present invention has developed a reading system.
In synchronization with the reading cycle of the solid-state image sensor of the dimensional array, the lamp for primary disaster illumination is emitted for a short period of time, and the movement of the original is stopped (reduced), similar to strobe photography, and the sub-image is This is intended to prevent a decrease in resolution in the scanning direction.

An embodiment of the present invention will be explained below with reference to FIG.

In the figure, the same reference numerals as in FIGS. 1 and 2 indicate the same or equivalent parts, 10 is a fluorescent lamp lighting control circuit, and 11 is a fluorescent lamp lighting control circuit.
is the image sensor control circuit.

The operation of these control circuits will be explained with reference to the timing chart of FIG.

φR is a basic clock signal υ for driving the image sensor 3, and data 08 for one pixel is read out for one clock. φTG is a synchronization signal for starting one line. φL is a light emission control signal fK which is delayed by a certain time from φTG and is synchronized with φTG. It is used to control the men-off of the fluorescent lamp. .

It is preferable that the light emission time TON be as short as the sensitivity of the image sensor 8 allows.

According to Honji fafU, even if the original is fed at a constant speed,
No reduction in resolution in the sub-scanning direction occurs.

According to the present invention, an original can be sent at high speed, a heavy original such as a book can also be sent, and the resolution in the sub-scanning direction does not deteriorate.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the conventional device, FIG. 2 is a side view of the conventional device, FIG. 3 is a diagram showing the configuration of an embodiment of the present invention, and FIG. 4 is a waveform diagram for explaining its operation. It is. l... Fluorescent lamp for illumination, 2... Imaging lens, 3...
・One-dimensional array solid state image sensor, 10... Fluorescent lamp lighting control circuit, 11... Image Figure 1 Figure 2

Claims (1)

[Claims] 1. In an apparatus for reading a graphical text box using a one-dimensional array of solid-state self-image sensors, the above-mentioned 1.
A figure reading device characterized in that a light source for illuminating a document is turned on in synchronization with the reading cycle of a solid state image sensor of a dimensional play. 2. In claim 1, the reading period of the solid-state image sensor of the one-dimensional array is shorter than the reading period of the solid-state image sensor of the one-dimensional array. A figure glare removing device characterized by turning on a light source for document illumination only for a period of time.