JPH0290781A - System for correcting offset of optical reader - Google Patents

Abstract

PURPOSE:To easily perform offset correction by storing a correct main scan/ subscan offset correction quantity in an EPROM at the stage of test adjustment, and outputting vertical and horizontal gate signals by correcting the main scan/ subscan offset quantity simultaneously with the application of a power source at a stage of using. CONSTITUTION:The main scan/subscan offset correction quantities of an optical reading unit and an original or a frame plate 7 are stored in a nonvolatile memory 6 in advance as reference values at the stage of test adjustment, etc., of an optical reader when starting up. The main scan/subscan offset quantities of the original or the frame plate 7 and the optical reading unit are compared with the reference value at the stage of using the optical reader when starting up, and the horizontal gate signal and the vertical gate signal are outputted by correcting the main scan/subscan offset quantity. In such a way, it is possible to automatically perform the correction of the main scan/subscan offset quantity in spite of the skill of a worker.

Description

[Detailed description of the invention] 〔overview〕 Regarding offset correction methods in optical reading devices.

The purpose is to automatically make all the subtle adjustments to the different offset amounts for individual optical reading devices.

An optical reading device that has a function of electrically performing offset correction includes an A/D converter that converts a video signal output from an image sensor into multi-value data, and an A/D converter that converts the multi-value data output from the A/D converter into l raster parts in sequence. The line buffer to store, the MPU, the non-volatile memory to store the offset correction amount, and the multi-value data of the line buffer sofa are read out to the MPU raster by raster at startup, at the stage of testing and adjusting the optical reading device, and the offset correction amount is stored in the MPU. a first means for determining the correction amount and storing it in the non-volatile memory; and at the stage of using the optical reading device,
At startup, the offset correction amount stored in the non-volatile memory is read to the MPU.

and second means for electrically performing offset correction.

[Industrial Application Field] The present invention relates to an offset correction method in an optical reading device, and in particular provides a means for eliminating the need for offset adjustment at the time of manufacturing the optical reading device and automatically performing offset correction during use. do.

[Prior Art] Fig. 5 is an explanatory diagram of offset correction of a fixed original type optical reading device in a conventional example, in which Fig. 5(a) shows main scanning and offset amount detection means, and Fig. 5(b) shows sub-scanning. An offset amount detection means and FIG. 5(c) respectively show an electric offset amount correction means in another conventional example.

In (a), (b), and (c) of FIG. 5, 51 is an image sensor, 52 is, for example, a CCD camera lens, and 5
3 is an optical reading unit including an image sensor 51 and a lens 52; 54 is a home position detection sensor;
55 is a bit switch 56 is an input port 57 is an MPU
, 58 indicates an output boat.

The main scanning offset amount detection means shown in FIG. Detects the difference between the main scan reading area and the edge of the document. Specifically, two workers check the position of the optical reading unit 53 in the main scanning direction while monitoring the output waveform of the image sensor with a synchroscope or by outputting the read image to a display or printer and checking the positional deviation at t1. Adjustments were made by hand.

The sub-scanning offset amount detection means shown in FIG. 54 detects the home position until the edge of the frame plate is detected in the same way as the main scanning and offset amount. 1 Based on this, the position of the optical reading unit 53 in the sub-scanning direction is adjusted. was done by hand.

In addition, as another conventional example, Fig. 5 (c) shows the cases of Fig. 5 (a) and Fig. 5 (b) in which the operator made subtle adjustments by hand while checking the main scanning and sub-scanning offset amounts. Instead of the conventional example, the offset correction is performed electrically, and the offset amount detected by one worker is set in the bit switch 55.

During operation, the value of this bit switch is loaded into a register within the MPU 57 via the input port 56.

The MPU 57 uses this offset amount to correct the horizontal and vertical gate signals and outputs them via the output port 58. Then, the horizontal and vertical positions of the optical reading unit 53 and the frame plate are corrected using these horizontal and vertical gate signals.

FIG. 6 shows an explanatory diagram of offset correction of a conventional document conveyance type optical reading device.

In FIG. 6, the same symbols as in FIG. 5 indicate the same parts,
The differences from FIG. 5 are a feed roller 61, a pinch roller 62. The present invention has a document conveying section composed of a document leading edge detection sensor 63.

In this case, when the document is conveyed, the document leading edge detection sensor 63 detects the leading edge of the document, detects the amount of sub-scanning offset in the vertical direction of the document, and the main scanning offset it in the horizontal direction of the document is determined as follows. This is done in the same manner as shown in FIG. 5 (a).

[Problems to be Solved by the Invention] However, the position adjustment between the frame plate and the optical reading unit or between the document and the optical reading unit requires that an operator read the position of the document or the frame plate and visually confirm the main/sub-scanning offset amount. ,
The main/sub-scanning offset amount is corrected manually or electrically by hand to correct the main/sub-scanning offset (1) and output horizontal and vertical gate signals.

In any of the above cases, there is a problem in that accurate correction requires considerable skill on the part of one operator.

SUMMARY OF THE INVENTION An object of the present invention is to provide an offset correction method for optical reading devices that can automatically make all the subtle adjustments to the amount of offset, which differs between individual optical reading devices.

[Means to solve the problem]

The present invention provides an optical reading device having a function of electrically performing offset correction in order to achieve the object of 0 or more, which includes an A/D converter that converts a video signal output from an image sensor into multi-value data, and an A/D converter that converts a video signal output from an image sensor into multi-value data. A line buffer that sequentially stores the multivalued data output from the D converter for l rasters, and an MPU.
and a non-volatile memory for storing the offset correction amount, and at the stage of testing and adjustment of the optical reading device, the multi-value data of the line buffer is read out for each raster to the MPU at startup, the offset correction amount is determined, and the above-mentioned non-volatile memory is provided. a first means for storing the offset correction amount in the non-volatile memory, and a second means for reading out the offset correction amount stored in the non-volatile memory to the MPU at the time of startup and electrically performing the offset correction when the optical reading device is used. Consists of.

[Effect]

According to the present invention, at the stage of testing and adjusting the optical reading device,
At startup, the main/subscanning offset correction amount between the optical reading unit and the document or frame board is stored in advance in nonvolatile memory as a reference value, and when the optical reading device is used, the amount of correction for main/subscanning offset between the document or frame board and the optical reading unit is stored at startup By comparing the main and sub-scanning offset amount with the reference value, the main and sub-scanning offset amount can be corrected and a horizontal gate signal and a vertical gate signal can be output. The main and sub-scanning offset amount can be corrected.

〔Example〕

FIG. 1 shows an explanatory diagram of the automatic fixed-document offset correction according to the present invention, FIG. 1 (A) is a block diagram of the automatic offset correction block, and FIG. 1 (B) is an explanatory diagram of the relationship between the test paper and the frame board. shows.

In Figure 1, ■ is an image sensor, 2 is an AMP, and 3 is an image sensor.
4 is an A/D converter, 4 is a line buffer 5 is an MPU, and 6 is an EPRO of non-volatile memory such as EEFROM.
M, 7 indicates a frame board, and 8 indicates a test paper.

At the stage of testing and adjusting the optical reading device, the image sensor 1 reads the position of the frame plate or test paper at startup, and the analog video signal read by the image sensor 1 is amplified by the AMP 2.

The A/D converter 1 converter 3 converts the data into multivalued data. A/D strange F! The multi-level data outputted from the A unit 3 is sequentially stored in the line buffer 4 in units of 1 and 2 minutes. The multivalued data in the line buffer 4 is read out to the MPLJ 5 raster by raster, and the EPR is performed as shown in the flowchart shown in FIG. 2, which will be described later.
Correct main and sub-scanning and offset correction amounts are stored in the main and sub-scanning offset area H1 in the EPROM 6 according to the first control program in the OM6.

When using the optical reader, the above EFROM is
The offset correction amount stored in the EPROM 6 is read out to the register of the MPU 5, and the main scanning offset amount and the sub-scanning offset amount are electrically calculated according to the second control program in the EPROM 6 as shown in the flowchart shown in FIG. Correct.

FIG. 2 shows a flowchart for automatic offset correction of the original fixed type optical reading device.

EPR main scanning offset amount and sub-scanning offset amount
The case of storing in the OM6 and the case of correcting the main scanning offset amount and the sub-scanning offset amount and outputting the vertical and horizontal gate signals will be explained with reference to FIG. 1(b) and FIG. 2. Note that the flowcharts 21 to 25 shown in FIG. 2 refer to the EPROM shown in FIG.
6, the flowcharts 26 to 28 shown in FIG. 2 are executed in accordance with the second control program.

First, main scan offset to EPROM6! Then, automatic offset correction for storing the sub-scanning offset amount is started (21).

When storing the sub-scanning offset amount in the EPROM 6, as shown in FIG. It is most accurate to count the numbers at the center point A.

Then, the above raster number is stored in EPROM 6 (23
).

When storing the main scanning offset amount in the EPROM 6, count the number of dots from the first dot of the effective bits of the image sensor l to the edge of the right end point B of the frame plate 7, as shown in FIG. 1(b). Then, the number of dots is stored in the EPROM 6 (25).

E where the main and sub-scanning offset amount as above is stored.
At the stage of using an optical reader having PROM6, i
t source is introduced (26). The predetermined main and sub-scanning and offset Wl from the EPROM 6 are set in the M shown in FIG.
On the other hand, the main/sub-scanning offset amount detected by the image sensor l and stored in the line buffer 4 is compared with the main/sub-scanning offset amount stored in the EFROM 6. , correcting the main and sub-scanning offset amounts and outputting horizontal and vertical gate signals (2B). These gate signals automatically correct the positional relationship between the frame 7 or the test paper 8 and the optical reading unit.

FIG. 3 is a diagram illustrating the automatic offset correction of the original transport type according to the present invention, and FIG. 4 is a flowchart of automatic offset correction of the optical reading apparatus of the original transport type.

At the stage of testing and adjusting the optical reading device, automatic offset correction is started to store the main scanning offset correction amount and the sub-scanning offset correction amount in the EPROM 6 (41).
.

When storing the sub-scanning offset correction amount in the EPROM 6, as shown in FIG. Count the number of rasters up to (42). This counting of the number of rasters can be done most accurately at the center point A.

Then, the above raster number is stored in EPROM 6 (43
).

When storing the main scanning offset correction amount in the EPROM 6, the number of dots from the first dot of the effective bits of the image sensor 1 to the edge of the right IB point of the test paper 8 is counted as shown in FIG. 44), and stores the number of dots in the EPROM 6 (45).

At the stage of using the optical reading device having the EPROM 6 in which the main/sub-scanning offset correction amount as described above is stored, the power is turned on (46), and the predetermined main/sub-scanning offset correction amount is read from the EPROM 6 as shown in FIG. (b) MP as shown
The data is transferred to the register in U5 (47), and compared with the multi-value data detected by the image sensor l, the main and sub-scanning offset amounts are corrected and horizontal and vertical gate signals are output (48). The positional relationship between one frame or test paper and the optical reading unit is automatically corrected by the gate signal.

(Effects of the Invention) According to the present invention, the correct amount of main and sub-scan offset 114 is already stored in the EPROM at the stage of test and adjustment of the optical reading device, and when the power is turned on and the optical reading device is used, Since the main and sub-scanning offset amounts can be corrected at the same time and the vertical and horizontal gate signals can be output, offset correction can be easily performed without requiring skilled work.

[Brief explanation of drawings]

FIG. 1 shows an explanatory diagram of the fixed original type automatic offset correction according to the present invention, FIG. 1 (A) is a block diagram of the offset automatic correction block, and FIG. , FIG. 2 is a flowchart for automatic offset correction of a fixed-document type optical reading device, FIG. 3 is an explanatory diagram of automatic seven-edge offset correction for a document transport type according to the present invention, and FIG. Correction flowchart. FIG. 5 is an explanatory diagram of offset correction of a conventional fixed document type optical reading device, FIG. 5(a) is a main scanning offset amount detection means, FIG. (C) is an electrical offset in other conventional examples)
! Correction Means FIG. 6 is a diagram illustrating offset correction of a conventional document conveyance type optical reading device. In the figure. ■... Image sensor 2... AMP 3... A/D converter 4... Line buffer 5... MPU 6... EPROM (non-volatile memory) 7... Frame board 8...・Test paper Figure 3: Document conveyance type offset self-a correction explanatory diagram in the present invention. Original fixed type 'je#! ' Reading table 1 on reading Soto self-help morbidity Hronayat guan 2 original sjR sending type light reading B! Offset automatic correction flowchart Diagram paper route ＼ Reading disease! Ofya-Soto correction explanatory diagram

Claims (1)

[Claims] In an optical reading device having a function of electrically performing offset correction, A that converts a video signal output from an image sensor into multi-value data.
A/D converter (3), a line buffer (4) that sequentially stores one raster worth of multi-value data output from the A/D converter, an MPU (5), and a non-volatile memory that stores the offset correction amount ( 6) At the time of start-up during testing and adjustment of the optical reading device, the multi-value data of the line buffer (4) is read out raster by raster to the MPU (5), and the amount of offset correction is determined and stored in the non-volatile memory (6). A first means for storing the offset correction amount stored in the non-volatile memory (6) at the time of startup of the optical reading device during use of the optical reading device;
5) and performs electrical offset correction.
An offset correction method for an optical reading device, characterized by comprising the following means.