JPS6243965A - Optical system adjusting device for picture reader - Google Patents

Abstract

PURPOSE:To attain highly accurate mounting adjustment of an image sensor by adopting a shape whose width is changed in the direction of height such as a triangle or trapezoid for a mark and displaying the mark in a mode of white on the black background or vide versa. CONSTITUTION:A positioning slit 14 for adjusting X axis 10 direction prolonged longitudinally at the center in the X axis direction, a slit set 16 for focus adjustment provided both sides of the slit 14 and a left mark 17 and a right mark 18 provided near both left/right ends of an adjustment pattern 32 by one each are displayed on the adjusting pattern 32. Further, hatched lines show the background black parts 13 smeared in black, while the slit 14, each slit of the slit set 16 and the marks 17, 18 are made white. Arithmetic processing is applied based on the read output of the adjusting pattern to find out the mounting error of the image sensor. Thus, the mounting adjustment of the image sensor is automated and the mounting with high accuracy is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical system adjustment device for an image reading device, and more particularly to an optical system adjustment device used for adjusting the mounting position of an image sensor.

In an image reading device using a conventional COD image sensor or the like, in order to adjust the installation of the image sensor, pattern 2 is correctly placed at the original position as shown in FIG.
A method is adopted in which this pattern 2 is irradiated with light from a light source 1 and the pattern image is read by an image sensor 6 through a lens 3.

The image sensor 5 is fastened to a mounting board 4 installed substantially perpendicularly to an optical axis (hereinafter referred to as a lens axis) 12 of the lens 3 using screws aa and ab.

Furthermore, the mounting board 4 for fixing the image sensor 6 is mounted in the same horizontal direction as the main scanning direction of the image sensor 6 (this is parallel to the X-axis
o) and in the vertical direction (this is referred to as the Y axis 11), and has a structure that is rotatable around the lens axis 12.

As shown in FIG. 7, the optical system adjustment pattern 2 includes a black background portion 13 represented by diagonal lines, and a positioning strip that is outlined in white in the horizontal or longitudinal center of the pattern 2 and extends in the vertical direction. !
J7) 14, an adjustment slit 15 outlined in white at the center of the vertical direction of pattern 2 and extending in the horizontal direction, and a collection of slits 16 for focus adjustment drawn near both sides of the positioning slit 14 are displayed. It consists of Then, the image sensor 6 is temporarily fixed to the mounting board 4, the pattern is read by the image sensor 6, and the position of the image sensor 6 is adjusted. Adjustment! 77) 15 is 0.5m+n
~o, has a width dimension d of 5 mm, and the image sensor 6
When reading a pattern, the image sensor 6 scans the adjustment slit 16 to check whether all lines are white. If all lines are white as a result of this scanning, it is determined that the image sensor 5 is correctly positioned. If all lines are not white, it is determined that the image sensor 5 is misaligned in the Y-axis direction 11 or rotationally misaligned about the R-axis 12. It is determined that the position is correct, and positioning adjustment is performed.

Problems to be Solved by the Invention However, in such a conventional optical system adjustment device, the adjustment pattern read by the image sensor 5 is formed by a belt-shaped adjustment slit 1 with a width of 06 to 08 mm.
6, the image sensor 6
If the scanning line deviates from the adjustment slit 15 or crosses the adjustment slit 16, the scanning line may be moved vertically, horizontally, or diagonally to align the line.
Since it was difficult to know in which direction and by how much it should be moved, the only option was to make fine adjustments manually using screws 6 and wrench 7 while looking at an onoroscope, for example. 1. Since the deviation in the installation position of the image sensor 6 cannot be quantitatively detected, the FI7 device cannot be electrically controlled and must be manually adjusted, but the COD image sensor 6 is currently on order. etc. adjustment accuracy is about 60μ,
At present, it is not possible to achieve greater accuracy than this through manual adjustment.

The present invention has been made by focusing on such conventional problems, and is capable of detecting the light receiving line position of an image sensor.
Based on this, electrical control is also possible and the adjustment method can be switched from manual adjustment to automatic adjustment, and the aim is to apply an optical system adjustment pattern to the adjustment device that makes it possible to improve adjustment accuracy. .

Means for Solving the Problems In order to achieve the above object, the present invention provides marks of a predetermined shape on both end portions, which are set corresponding to the light receiving line of the image sensor of the reading device, and are arranged in opposite directions upward and downward. The gist of this invention is an optical system adjustment device for a reading device using an adjustment pattern provided in the following manner. The mark has a triangular shape, and the trapezoidal mark has a similar shape in which the width changes in the height direction, and is displayed in white on a black background or vice versa. When adjusting the mounting position of the image sensor, the adjustment pattern including the marks at both ends is scanned and read.

When the operational image sensor scans the adjustment pattern, marks are detected at both the left and right ends of the adjustment pattern.

This mark has a shape such as a triangle or trapezoid whose width changes from the top to the bottom, so the left mark is detected by the number of bits of the image sensor, and the right mark is detected by the number of bits of the trench. By memorizing this value and comparing it with a preset value, you can determine what kind of directional relationship the image sensor's scanning direction has with respect to the adjustment pattern.
), it is possible to determine whether the image sensor is tilted or vertically displaced. Therefore, if a corrector is determined based on the above-mentioned indexing amount and a pulse motor or the like connected to the image sensor is controlled, automatic adjustment of the image sensor becomes possible.

Embodiment FIG. 1 is a diagram showing an embodiment of the present invention. The optical system adjusting device according to this embodiment has almost the same basic configuration as the conventional example shown in FIG. The image sensor 5 is fixed to the mounting board 4 with screws 8a and sb so as to be substantially perpendicular to the axis 12 of 3. In this embodiment, the mounting board 4 is movable in the main scanning direction, that is, in the X-axis 10 direction and the Y-axis 11 direction,
In addition to being rotatable around the L-axis 12, the mounting board 4 is also equipped with an The shaft pulse motor 2o and an L-axis rotation pulse motor 22 that rotates around the L-axis 12 are connected to each other.

Each pulse motor 20, 21, 22 is connected to and controlled by a control circuit that generates a control signal based on a read signal from the image sensor 6.

An example of the adjustment pattern 32 used in the optical system adjustment device according to this embodiment is shown in FIG.

In FIG. 2, a shows the configuration of the adjustment pattern 32, and b shows the waveform of the read output when this adjustment pattern 32 is read. The adjustment pattern 32 includes a positioning slit 14 for adjustment in 10 directions of the X-axis extending vertically in the central part of the adjustment pattern 32 in the X-axis direction, and a slit collection part for focus adjustment provided on both sides of the positioning slit 140. 16, and a left mark 17 and a right mark 18, one each provided near both left and right ends of the adjustment pattern 32, are displayed. In FIG. 2a, the shaded area indicates the point portion 13 filled in black, whereas the slit 14, each slit in the slit gathering portion 16, and the marks 17 and 18 are outlined.

The left mark 17 and the right mark 18 are formed in a triangular shape, and are displayed upside down to each other, with the left mark 17 having its apex facing up, and the right mark 18 having its apex facing down. 3 shows the positional relationship between the left mark 17 and right mark 18 in an easy-to-understand manner. FIG. 3 is an enlarged view of the left mark 17 and right mark 18 shown in FIG. 2, and the distance between the marks 17 and 18 is shortened. As can be seen from this figure, the marks 17 and 18 are set in a positional relationship such that one (for example, the left mark 17) and the other (the right mark 18) overlap in the height direction, and the left mark 17 base 17
The amount of overlap determined between a and the bottom side 18a of the right mark 18 is set to D. This overlap measure has approximately the same dimension as the width dimension d of the adjustment slit 16 in the conventional adjustment pattern 2 shown in FIG. .

FIG. 4 is a diagram showing the circuit configuration of a device that detects and controls deviations in the mounting state of the image sensor 5 by reading the adjustment pattern shown in FIG. 3.

This control device 3o includes an A/D converter 32 that converts an analog signal, which is an optical signal obtained by the image sensor 6 reading the adjustment pattern 32, into a digital signal; a random access memory (hereinafter referred to as RAM) 33 for temporarily storing signals;
Read write-only memory (hereinafter referred to as RO) stores theoretical values that serve as reference data obtained by reading test patterns.
A central processing unit (hereinafter referred to as C
It consists of a CPU 36 (referred to as a PU) and a memory 3e that stores operation instruction data for the CPU 35.

This detection device 3o is connected via an input/output interface 37 to a panavi ivy 38, an air cylinder 39, a sensor 40 . Pulse motor 20, 21
．． 22, a display 42, etc.

The operation of the optical system adjustment device having such a configuration will be explained. First, the adjustment pattern 32 is installed at a document reading position, while the image sensor 6 is attached to the mounting board 4. The image sensor 6 reads the adjustment pattern 32 and photoelectrically converts the optical signal into an analog electrical signal, and the A/D converter 32
The A/D converter 32 converts the analog signal sent from the image sensor 6 into a digital signal, and this digital signal is stored in the RAM 33 as image data. An example of image data stored in this RAM 33 is shown in FIG. Next, the CPU 35 uses the RAM 33 and ROM
The image data and reference data are read from 34, and both data are compared and calculated to determine deviations in the X-axis, Y-axis, and rotational direction.The pulse motors 20, 21, and 22 are controlled according to each deviation. cormorant.

In this control operation, the lens 3 is first moved in the axial direction while looking at the positioning slit 14 in the center of the adjustment pattern 32, the amount of deviation in the X-axis direction is calculated by the CPU 35 in a temporary focus state, and the pulse motor is 21 to generate a control signal and move the image sensor 6 in the X-axis direction.

Next, in order to detect the deviation in the Y-axis direction and/or the deviation in the axial direction of the lens 3, the number of bits is counted when the left and right marks 17.degree. 18 are read and scanned.

That is, in FIG. 3, when the image sensor 6 reads in the main scanning direction, if the reading is carried out along the scanning line indicated by the two-dot chain line S1, then this reading scanning line S,
Since the left and right marks 17 and 18 fall within the overlap of 11DO, it is determined that the deviations in the Y-axis direction and around the lens axis are zero or within the allowable range. This state is uniquely determined by calculating the number of readings and focuses of the left and right marks 17 and 18 by the image sensor 6. Therefore, if the read scanning state of S can be determined by reading out the number of read bits in the image data from the RAM 33 and reading out the theoretical value from the ROM 34 and performing arithmetic processing, there is no need to adjust the Y-axis or rotation of the six image sensors. Become.

On the other hand, in the same reading scan as described above, if the thread is increased along the scanning line indicated by the two-dot chain line S2 in FIG.
8 is read at a predetermined inclination angle, and this reading scanning angle and deviation in the Y-axis direction are uniquely determined by calculating the number of bits read by the image sensor 6 of the left and right marks 17 and 18. Therefore, the CPU 35 reads the number of read bits in the image data from the RAM 33, reads the theoretical value from the ROM 34, and performs arithmetic processing to determine the amount of deviation and rotational deviation of the image sensor 5 in the Y-axis direction. Based on this, the CPU 35 generates a control signal. This control signal causes the pulse motors 20, 22
is operated and controlled, and based on this, the image sensor 6 is moved in the Y-axis direction and rotational direction. During such image sensor movement adjustment, the image sensor 6 is moved by the pulse motors 20 and 21.
．． 22, the positional accuracy of the image sensor 6 is ±
A high accuracy of 6μ can be obtained.

FIG. 6 is a diagram showing a second embodiment of an adjustment pattern used in the optical system adjustment device of the present invention. In this embodiment, two white marks 26, 27, 28.degree. 29 are displayed on each end of the adjustment pattern 45.

In this embodiment, the marks 26, 27, 28, 29 are all formed in a triangular shape. Mark 26 on the left
．． 27, the leftmost mark 26 is displayed with its apex up, while the mark 18 next to it is displayed with its apex down, so that they are upside down. Also, regarding the marks 28 and 29 on the right side, they are upside down, with the rightmost mark 29 having its apex facing up, and the mark 28 next to it having its apex facing down.

The bottom sides of mark 26 and mark 29 are aligned on the same horizontal line within adjustment pattern 45, while mark 2
The bottom sides of the mark 7 and the mark 28 also coincide on the same horizontal line within the adjustment pattern 46. Further, the set of marks 26, 29 and the set of marks 27, 28 are set in a positional relationship so that there is an overlap in the height direction between one and the other, as in the first embodiment, Also, the base 2 of one set
The amount of overlap determined by the 68° 29a and the bottom sides 27a and 28a of the other set is set to D, which defines the permissible range of angular deviation of the image sensor 6 in the Y-axis direction and around the lens axis. In addition, in the adjustment pattern of this embodiment, the same positioning slit 1 as in the first embodiment is used.
4, and a focus adjustment slit collection section 16 are provided.

When the adjustment pattern 46 having such a configuration is used in an optical adjustment device, unlike in the first embodiment, when the image sensor 6 reads and scans, the mark 26
, 27, 28, and 29, the positional deviation of the image sensor 5 in the Y-axis direction and the angular deviation around the lens axis can be detected. That is, whether or not the image sensor 6 has read each mark 26, 27, 28, 29 is indicated by an on or off signal, and all marks 26, 27, 28, 29 have been read (for all marks). On), it is determined that the image sensor 6 is correctly installed. For example, when only the marks 26 and 29 are on, it is determined that the image sensor 6 is performing a reading operation above the normal position, and when only the marks 27 and 28 are on, it is determined that the image sensor 6 is performing a reading operation below the normal position.

1, when mark 26.28 is on, the image sensor 5 moves downward to the right with respect to the adjustment pattern, and mark 27.29
When is on, it is determined that the reading operation is performed upward to the right. Further, when the marks 26, 28 and 29 are on, it is found that the image sensor 6 is shifted upward from the normal position and the reading operation is performed downward to the right, and various mounting manners of the image sensor 6 become clear. Therefore, the operator can finely adjust the mounting position of the image sensor 6 while observing the ON or OFF state of each mark 26, 27, 28, 29, thereby making the work of mounting the image sensor 6 easier.

In the above first and second embodiments, an example was shown in which the mark for detecting deviation in the Y-axis direction and rotational deviation around the lens axis was triangular, but the mark shape is triangular. For example, without being limited to a trapezoid,
Any other material may be used as long as the width gradually increases from the top to the bottom.

As described in detail, according to the present invention, an adjustment pattern with marks of a predetermined shape on both ends is installed at the adjustment pattern installation position of the optical system adjustment device, and based on the read output of this adjustment pattern, Since the arithmetic processing is performed to determine the installation error of the image sensor, various effects such as automation of the image sensor installation adjustment work and high-precision installation possible can be obtained.

[Brief explanation of the drawing]

17 - FIG. 1 is a schematic diagram of the basic configuration of an optical system adjustment device according to an embodiment of the present invention, FIG. 2a is a schematic diagram of a first embodiment of an adjustment pattern used in the optical system adjustment device, Figure 2 is an output waveform diagram when the above adjustment pattern is read by an image sensor, and Figure 3 is an output waveform diagram of the adjustment pattern shown in Figure 2a.
FIG. 4 is a block diagram of a control circuit that controls the position adjustment of the image sensor based on pattern information read by the image sensor, and FIG. A schematic diagram of a second embodiment of the adjustment pattern used in the optical system adjustment device, FIG. 6 is a schematic diagram of the conventional optical system adjustment device, and FIG. 7 is a schematic diagram of the adjustment pattern used in the conventional optical system adjustment device. It is a pattern diagram. 1...Light source, 2.32.45...Adjustment pattern, 3...Lens, 4...Mounting board, 6...Image Sensor, 17, 18, 2
6,27,28.29...7-ri, 20, 2
1, 22...Pulse motor. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure/--Ikko I, 3-m-lens

Claims (1)

[Claims] An adjustment pattern installed on the document placement surface, an image sensor that reads this adjustment pattern, a mounting board that mounts and supports this image sensor, and is operatively connected to this mounting board, and moves and rotates this mounting board to read the image. It has a pulse motor that adjusts the mounting position of the sensor, and a control circuit that generates the pulse motor control signal based on the adjustment pattern reading information from the image sensor, and the adjustment pattern corresponds to the light receiving line of the image sensor. At the same time, a mark having a top and a bottom and having a shape that gradually expands from the top to the bottom is installed at both end portions so that the top and the bottom are in an upside-down relationship with each other. An optical system adjustment device for an image reading device, characterized in that: