JPS60240268A - Picture reader - Google Patents

Abstract

PURPOSE:To attain accurate extraction and read of a designated area according to a scale by providing an index possible for optical read to a prescribed position of a positioning scale member. CONSTITUTION:In one line revision reading, when an index 12 is detected, whether or not it is detected at first is checked, and when it is detected at first, the next line is read again and when the index 12 is detected again, it is discriminated that the index 12 is detected. When it is discriminated that the index 12 is detected, the reading position of the index 12 is XB at a CCD8 so as to calculate the home position of the CCD8. Thus, the main scanning direction read position of the CCD8 and the scale 10x are made coincident. Then the extraction/read of the designated area is executed accurately according to the scale without needing any special adjusting means.

Description

[Detailed description of the invention] Technical field The present invention relates to an image reading device.

Prior Art In recent years, the applicant has proposed a scanner that electrically reads a document image with an image sensor such as a CCD, processes it digitally to produce a digital image signal, and outputs this image data to an image output device such as a printer or a personal computer. has been done. In order to facilitate layout editing on the image output device side, this scanner moves and stops the reading optical system arbitrarily in the sub-scanning direction to image any specified area in the main-scanning and sub-scanning directions. One of its characteristics is that it can extract and read out information, which is different from conventional scanners such as facsimile machines.

FIG. 1 schematically shows the reading optical system of the scanner. While exposing and scanning an original 2 set on an original glass 1 with a lamp 3, the reflected light is sent to a first mirror 4.
, a second mirror 5, a third mirror 6, and a lens 7 to form an image on an image sensor, for example, a CCD 8, and image information is electrically read line by line. Here, the lamp 3 and the first mirror 4 are made into a first traveling body, and the second mirror 5 and the third mirror 6 are made into a second traveling body, and the latter scans at a speed of 172 of the former. .

In such a flat document scanning type scanner, the reading operation can be started and stopped at will, and it is possible to read not only the entire document image, but also extract only the image information of a desired specified area, not the entire document image. It is set so that it can be read out. The read command at this time is ESC + "do + 'RD'ten" (X + Δx, y + ΔY
)'+CR. Here, X, Δx, y, ΔY
As shown in FIG. 4, indicates a rectangular area (oblique view) in the document 2 that is to be extracted and read. In this way, in the read command, if you key in X, Δx, y, and ΔY in 3-digit decimal numbers according to the ASCII code to specify the area you want to extract and read, the range in the main scanning direction and sub-scanning direction is regulated. Only that area is read. The operation of the reading optical system at this time is as follows: First, the lamp 3, etc. is fast-forwarded by a skip operation to a position in the sub-scanning direction Y, and then it moves at a predetermined speed from the reading start sub-scanning position Y to the reading end sub-scanning position Y + ΔY. It scans and reads each line. Note that sampling in the main scanning direction (X direction) is performed purely electrically.

When the document has a sampling reading function as described above, it is preferable to provide an L-shaped scale member 9 on the document glass 1, as shown in FIG. 2, so that the operator can easily set the sampling position. In other words, the X direction of this scale member 9,
■Direction scale 10x.

It is sufficient to set the specified area according to 10Y. 1
1 is the main body case.

In this case, in order to achieve sampling accuracy, the scale member 9
It is necessary that the positional relationship between the reading optical system and the moving body of the reading optical system be accurate. However, due to variations in mechanical parts or precision during assembly, the scale of the scale member 9 is 10X.
, a deviation may occur between the IOY and the actual reading position. For example, in the scale member 9 in the sub-scanning direction, the home position is the Yo position of the scale 10y, but the home position on the mechanical side may not match this. Furthermore, although the main scanning direction is based on the position Xo of the scale 10x of the scale member 9, this position may not coincide with the origin on the CCDg side.

In order to eliminate such deviations, an adjustment mechanism is required, and corrections must be made through adjustment work, which is troublesome and time consuming.

Purpose The present invention was made in view of the above points, and even if there is a misalignment in the positional relationship between the reading optical system and the positioning scale member, it is possible to perform sampling reading without requiring mechanical adjustment means or adjustment work. An object of the present invention is to obtain an image reading device that can accurately perform image reading.

Structure An embodiment of the present invention will be described based on FIGS. 3 and 4. FIG. Components that are the same as those shown in FIGS. 1 and 2 are designated by the same reference numerals, and description thereof will be omitted. In this embodiment, the scale member 9
An index 12 that can be read by a reading optical system is provided at the center of the back surface of the X-axis portion by printing or other means. This indicator 12 is several millimeters square. However,
The position and shape of this indicator 12 are the scale 10 of the scale member 9.
It is arbitrary as long as the positional relationship (coordinates) with X and IOY is determined, and it does not have to be in the center. Moreover, it does not have to be the scale member 9 itself.

The home position in the main scanning direction and the sub-scanning direction is calculated based on such an index 12.

So, now, index 12 lo ill (Xs, Ye
), the processing will be explained with reference to FIG.

The home position detection operation shown in FIG. 4 is performed when the power is turned on or by an external instruction. First, the traveling body of the reading optical system makes a return operation beyond the home position. Next, sub-scanning of the traveling body is performed, and reading is performed line by line. When index 12 is detected in this one line update reading, it is checked whether it is detected for the first time, and if it is the first time, the next line is read again, and when index 12 is detected again, index 1 is detected.
It is determined that 2 has been detected. This is to prevent erroneous detection, since if it is done only once, it may be determined that the index 12 is due to reading of dust or the like (therefore, it may be checked twice or more). In this way, when it is determined that the index 12 has been detected, the home position of the CCD 8 may be calculated so that the reading position of the index 12 becomes XB on the CCD 8. As a result, the scale 10x and the reading position of the CCD 8 in the main scanning direction match. On the other hand, in the sub-scanning direction, (Yo-Y
By setting the home position value determined by e) and moving the traveling body by that amount, the traveling body will move to the home position position on the scale member 9, and the home positions of both will match. become.

The traveling body will perform subsequent document image reading operations based on the home position set in this way.

In other words, in this embodiment, even if there is a mechanical deviation, the home position of the traveling body or CCD is corrected based on the scale 10x and 10y positions of the scale member 9 without requiring any adjustment. This makes it possible to easily and accurately sample and read any specified area.

By the way, when detecting the index 12, if for some reason the index 12 cannot be detected even after reading the specified number of lines, a fixed value predetermined as the home position value is used as the home position in the main scanning direction or the sub-scanning direction. It is given as a position in the scanning direction.

Effects As described above, the present invention provides an optically readable index at a predetermined position on the positioning scale member side, so even if there is a positional deviation between the positioning scale member and the mechanical side, the reference position remains the same as the positioning scale member. You can control the side correction to match the reference position.

Therefore, there is no need for special adjustment means or strict selection of parts.
This allows sampling and reading of designated areas to be performed accurately according to the scale.

[Brief explanation of drawings]

Figures 1 and 2 show the content of the existing proposal; Figure 1 is a schematic side view of the reading optical system, Figure 2 is a plan view, and Figure 3 is a bottom view showing an embodiment of the present invention. , FIG. 4 is a flowchart showing the home position detection process. 1... Original glass, 2... Original, 9... Scale member, 10x~IOY... Scale, 12... Index applicant Rico Co., Ltd. - 5J Figure 37

Claims (1)

[Claims] The reading optical system is arbitrarily moved back and forth in the sub-scanning direction and stopped.
In an image reading device capable of extracting and reading out image information of any specified area of a document in the main scanning direction and the sub-scanning direction, a positioning scale member for specifying the specified area of the document is provided on the document glass, and this positioning scale member is provided on the document glass. an index set on the scale member itself or a member in a positional relationship related thereto in a constant positional relationship with respect to the scale of the positioning scale member, optically readable by the reading optical system, and regulating the operation of the reading optical system; An image reading device characterized by being provided with.