JPS6024765A - Adjusting method for image scanner - Google Patents

Abstract

PURPOSE:To make the device precisely succeed an image signal output of two image sensors avoiding lacks and overlap of signals by changing start timing of the sensors. CONSTITUTION:Outputs of image sensors 15 and 16 are binerized by A/D conversion circuits 17 and 18, an outputs of the A/D conversion circuit 17 is stored in the front half section of an image signal memory 19, and an output of the A/D conversion circuit 18 is stored in the last half section of the memory. When a standard original 10 is to be read, a distance between standard marks 11 and 12 is detected by a distance detection circuit 20 from the output of the image signal memory 19. A start signal of the image sensor is outputted from a start timing control circuit 30 so that the results will be equal to normal values.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to an adjustment method for an image scanning device in which one line in the scanning direction of a document is divided and scanned by a plurality of reading devices.

(B) Prior art In conventional image scanning devices such as facsimile IJ, a document sent in the sub-scanning direction is divided in the main scanning direction and read and scanned by multiple reading devices. Misalignment, overlapping, and omission of images are likely to occur in adjacent parts of the range, and it is difficult to adjust these adjacent parts by mechanically adjusting the optical system. Furthermore, even if the optical system is once precisely adjusted, a shift of several bits can easily occur due to temperature changes, vibrations, etc., and it is cumbersome to adjust the optical system each time.

(c) Purpose of the Invention The present invention provides an image scanning device in which one line in the scanning direction of a document is divided and scanned by a plurality of reading devices, in which images are overlapped and extracted in adjacent portions of the scanning range of each reading device. This is to prevent such occurrences.

B) Structure of the Invention The present invention is an image scanning device in which one line in the scanning direction of a document is divided and read and scanned by a plurality of reading devices, and the output from an image sensor provided in each reading device is divided into two. An A/D conversion circuit that converts into values; an image signal memory that stores the image signal of this A/D conversion circuit; a circuit that detects the distance between the change points of the image signal; and a mJ image sensor that drives the image sensor. and a start timing control circuit that changes a start pulse to read and scan a reference document on which reference marks having a fixed positional relationship are provided on the paper, detect the distance between the reference marks on the image signal, and calculate the distance. This is an adjustment method for an image scanning device, characterized in that adjacent points between a plurality of reading devices are brought into alignment by changing a start pulse for driving the image sensor so that the image sensor reaches a predetermined value.

(e) Example An example of the present invention will be described below with reference to the drawings. The document (1) is conveyed in the sub-scanning direction (the direction indicated by the arrow) by the paper feed roller f21 +31 and the tension roller f41 +51. Then, read the manuscript (1) at the reading position (60
Irradiate with a trowel and a light source (7). The reflected light from the original (1) is read and scanned by a reading device (9) via a lens thread (8). As shown in FIG. 2, this reading device +91491 divides and scans one line of a document (1) in the main scanning direction. In this reading device (9), a plurality of photoelectric conversion elements are arranged in one row in the longitudinal direction.

Reference document 0 (1 is a reference mark on a white background)
'y:r is drawn across the center.

Figure 3 shows the accurately adjusted optical system of the above-mentioned Kikutsu manuscript O11.
In this case, (Al is the output of the image sensor responsible for the left half, (B) is the output of the image sensor responsible for the right half. tD in the figure) corresponds to the effective reading width. During the period of
Becomes 1. (al (bl each indicates the start timing of the image sensor.
short)' is the state written to memory. At this time,(
(1) The distance between 'tel' matches the distance between multiple marks, and there is no overlap or omission of signals at adjacent points.

Figure 4 shows the image signal when the optical system is misaligned (El
(Fl CG+ when the signal is lost at the adjacent point, (H)
(1) and (J) are the results when the signal loss is restored normally by delaying the start signal of the image sensor and adjusting the image scanning loading. As the optical system in charge of the right side in Figure 4 (Fl) shifts to the right (outward), the position corresponding to (el in Figure 3) moves to the left and becomes (fl), and in the image signal memory output CG+ , line segment opening 1111(dl'(f) is smaller than fdl'(e) in the normal case, and the corresponding signal is lost.

The timing of the image sensor's start signal and image signal output is determined by the structure of the image sensor. Therefore, by delaying the start signal of the image sensor by (m) as shown in FIG.
If you start at ', the image signal output will also be shifted by Q,
ffl will come to position (b). Then, the memory output written during the reading period (in Jl, the line segment distance (di') returns to normal, and the
is equal to , and there is no signal loss.

FIG. 5 is a block diagram of a circuit showing one embodiment of the present invention. In this figure, the output of the image sensor (151) and the output signal are respectively binarized by the A/D converter circuit aη081, and the output of the A/D converter circuit a71 is the image signal memo I709.
), and the output of the A/D conversion circuit am is accumulated in the latter half.

In the position adjustment mode (when reading a reference document), the distance between the reference marks from the output of the image signal memory 0 is detected by the distance detection circuit CD, and the start timing is controlled so that the result is equal to the normal value. Output the image sensor start signal from the circuit (a).

FIG. 6 is a circuit diagram showing an example of the distance detection circuit and the start timing control circuit (a) shown in FIG.
This figure is a timing chart for explaining the operation timing of FIG. 6.

Next, the present invention will be explained in more detail with reference to FIGS. 6 and 7.

When the basic document is set and the position adjustment mode is entered, the terminal 1 in Figure 6 becomes logic O, allowing the up/down counter Gυ to count, and the flip-flop ■ is set and reset via the inverter (c). Release the condition. Furthermore, AND gate (24103 is passed through, 5-state latch 6 gold is enabled, and at the same time, AND gate (to) is enabled.
open. Start signal for reading one line (Figure 7)
) is applied to the terminal (j+), and after resetting the counter (21+ 03 and the flip-flop (b)), the start signal for the image sensor of 051 in Fig. 5 is also applied to the terminal tel at the timing of fFl in Fig. 5S7. Then, the flip-flop (b) is set and the AND gate (c) is opened.The image sensor drive clock is applied to the terminal [dl, and the counter (
The count value is compared with the output of the up/down counter 0) by the magnitude comparator 1. The comparison output of the magnitude comparator (to) is set to be logic 1 only when both inputs are equal, so the count value of the counter (g) is 1 greater than the output of the up/down counter 01). At the moment when the inverter 01 flip-flop is opened, the AND gate (7) is closed and the counter stops counting. At this time, the terminal (f117) output becomes the signal shown in FIG. 7 (G), which becomes the start signal for the image sensor 161 in FIG. Figure 7 + D
Get +. This image signal is applied to the clock terminal ta+ of the flip-flop (25), and the clear terminal of the flip-flop is connected to the terminal fbl through an AND gate (incorporated).
A mask signal (FIG. 7(C)) is input from , and as a result, a signal corresponding to the line segment distance (FIG. 7(E)) is outputted to the AND gate. The readout clock of the image signal memory (Fig. 5 (1!n) is input to the terminal tc+, and through the AND gate, the readout clock of the image signal memory (Fig.
The period b+ is counted by the counter 211. This count value is determined by a magnitude comparator (company).
It is compared with a predetermined value N corresponding to the correct line segment distance.

The magnitude comparator (c) outputs logic 1 when the count value is smaller than N and is equal to or greater than logic O1. If the distance between the line segments of the image signal is smaller than a predetermined value, the count value of the counter c11 is Nyorimo smaller,
The output of the magnitude comparator (2) becomes logic O and opens the AND gate (+5) through the inverter (11).

After that, a line end signal (Fig. 7 (B)) indicating the end of reading one line is input from the terminal (h), and the signal enters the up count terminal of the up/down counter 0η via the AND gate (6) and increments the count by one. Proceed. As a result, the next time one line is read, in particular, the second sensor start signal is outputted with a delay of one sensor chlorine from the current reading. After reading several times in this way, the count value of the counter (21) becomes N.
When it becomes equal to, the magnitude comparator (goods)
The output of the flip-flop (22c2
3. Reset the flip-flop (2) via AND gate t2 (A) □□□, and then AND gate C3FJ@
3 (6) is closed to stop counting the up/down counter 0υ. Further, the enable terminal of the state latch (b) is set to logic 0 through the AND gate Gl, and the output of the up/down counter 0υ at that point is latched. In this way, the start timing of the image sensor is fixed when the distance between the lines of both signals reaches a predetermined value.

Up to now, the operation has been described when the line segment distance is smaller than the predetermined value N and is 0, but when it is larger than N, the arp-down counter c3]) is sequentially counted down and made smaller than N at one time. The rest is as already stated. 6- Stitch latch and AND gate are operated by backup power supply, and even after the main circuit power is turned off,
The count value corresponding to N is stored. Therefore, the next time the position is adjusted, the up/down counter 01) starts from the current count value. Terminal (1) is normally logic O and becomes logic 1 after entering the position adjustment mode. By changing the signal, it can be passed accurately without overlapping or missing signals,
There is no need for troublesome mechanical fine-tuning for image signal connections.

[Brief explanation of the drawing]

The drawings relate to the present invention; FIG. 1 is a schematic configuration diagram of an image scanning device viewed from the side, and FIG. 2 is a schematic configuration diagram viewed from the top. Figures 3 and 4 are waveform diagrams showing the output from the image sensor, and Figure 3 (-At (Bl
(C) is properly adjusted, Fig. 4 (G)) tF'
1 (Gl) If a positional shift occurs, the
l (, Tl are adjusted according to the present invention). Fig. 5 is a block diagram showing an embodiment of the present invention.
This figure is a circuit diagram showing an example of the distance detection circuit and start timing circuit of FIG. 5, and FIG. 7 is a timing chart diagram for explaining the operation timing of FIG. 6. (9)...reading device, (Ill...standard manuscript, (1
1), (121...Standard mark, (19, Scream...Image sensor, [171, +1 mark...A/D transformation circuit (G)...Both signal memory, ■... Distance detection circuit, (30)...Start timing control circuit. Fig. 1 Fig. 2 340 - Fig. 3 Fig. 5 Fig. 6 Fig. 7"7

Claims (1)

[Claims] (1) An image scanning device that divides and scans one line in the scanning direction of a document using multiple reading devices, which binarizes the output from the image sensor provided in each reading device.
a /D conversion circuit, an image signal memory that stores image signals from the A/D conversion circuit, a circuit that detects a distance between changing points of the image signal, and changes a start pulse that drives the image sensor. and a start timing control circuit, reads and scans a reference document in which reference marks having a certain positional relationship are provided on paper, detects the distance between the reference marks on the image signal, and reaches a predetermined value. An adjustment method for an image scanning device, characterized in that adjacent points between a plurality of reading devices are brought into alignment by changing a start pulse for driving the image sensor.