JPH0356506B2 - - Google Patents

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.

BACKGROUND TECHNOLOGY In an image reading device using a CCD image sensor or the like, in order to adjust the installation of the image sensor, a pattern 2 is correctly placed at the original position, and a light source 1 is attached to this pattern 2, as shown in FIG. A method is adopted in which a pattern image is read by an image sensor 5 through a lens 3.
The image sensor 5 is fastened to the mounting board 4, which is installed substantially perpendicularly to the optical axis (hereinafter referred to as the lens axis) 12 of the lens 3, using vias 8a and 8b. Also, a mounting board 4 that fixes the image sensor 5
is movable in the same horizontal direction as the main scanning direction of the image sensor 5 (this is the X-axis 10) and in the vertical direction (this is the Y-axis 11),
Further, it has a structure that allows rotation around the lens axis 12.

As shown in FIG. 7, the optical system adjustment pattern 2 includes a black background portion 13 indicated by diagonal lines, and a positioning slit 14 outlined in white in the horizontal or longitudinal center of the pattern 2 and extending vertically. And pattern 2
An adjustment slit 15 outlined in white at approximately the center in the vertical direction 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. Then, the image sensor 5 is temporarily fixed to the mounting board 4, a pattern is read by the image sensor 5, and the mounting position of the image sensor 5 is adjusted. Adjustment slit 1
5 has a width dimension d of 0.5 mm to 0.8 mm, and when the image sensor 5 reads the pattern, the image sensor 5 scans the adjustment slit 15 to determine whether or not all lines are white. Find out. As a result of this scanning, if all lines are white, 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 this has occurred, 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 consists of a band-shaped adjustment slit 15 with a width of 0.5 to 0.8 mm. Therefore, when the scan line read by the image sensor 5 deviates from the adjustment slit 15 or crosses the adjustment slit 15, it is necessary to move the scan line vertically, horizontally, or diagonally to align the line. If you don't know how much you need to move in a direction, for example while looking at an oscilloscope,
The only option was to make fine adjustments manually using screws 6 and wrench 7. In addition, the image sensor 5
Because the displacement of the mounting position cannot be quantitatively detected, the position adjustment cannot be controlled electrically and must be done manually, but the adjustment accuracy of the CCD image sensor 5 etc. is currently around 50μ, and this At present, the above accuracy cannot be expected by manual adjustment.

The present invention has been made in view of these conventional problems, and it is possible to detect the light receiving line position of the image sensor, and based on this, electrical control is also possible, changing from manual adjustment to automatic adjustment. The purpose of this invention is to apply to an adjustment device an optical system adjustment pattern that enables switching methods and improves adjustment accuracy.

Means for Solving the Problems In order to achieve the above object, the present invention has a mark set corresponding to the light receiving line of the image sensor of the reading device, and a mark of a predetermined shape is set at both end portions in a pair upside down and opposite to each other. The gist of this invention is an optical system adjustment device for a reading device using a provided adjustment pattern. The mark has a triangular, trapezoidal, or similar shape in which the width dimension changes in the height direction, and is displayed as a white outline on a black background or vice versa. Then, when adjusting the mounting position of the image sensor, the adjustment pattern including the marks at both ends is scanned and read.

Effect When the image sensor scans the adjustment pattern,
Marks are detected at both 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 any number of bits of the image sensor can detect the mark on the left, and no matter how many bits of the image sensor, the mark on the right can be detected. By memorizing this value and comparing it with a preset value, it is possible to determine the directional relationship between the scanning direction of the image sensor and the adjustment pattern. It is possible to determine the deviation in the vertical direction.
Therefore, by determining the correction amount based on the index amount and controlling a pulse motor or the like connected to the image sensor, 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 arranged so that the image sensor 5
is fixed to the mounting board 4 with screws 8a and 8b. In this embodiment, the mounting board 4 is not only movable in the main scanning direction, that is, in the X-axis 10 direction and the Y-axis 11 direction, and also rotatable about the L-axis 12. This mounting board 4
X-axis pulse motor 2 that moves the
1, a Y-axis pulse motor 20 for moving in the direction of the Y-axis 11, and an L-axis rotation pulse motor 22 for rotating around the L-axis 12 are respectively connected. Each of the pulse motors 20, 21, and 22 is connected to and controlled by a control circuit that generates a control signal based on a read signal from the image sensor 5.

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 extending vertically in the X-axis direction for adjustment in the 10 X-axis directions, and a slit gathering portion for focus adjustment provided on both sides of the positioning slit 14. 1
6 and 1 near both left and right ends of the adjustment pattern 32.
Left mark 17 and right mark 18 provided individually
is displayed. In Figure 2a, the shaded area is the black background area 13 filled in black.
In contrast, 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. ing.
FIG. 3 shows the positional relationship between the left mark 17 and the right mark 18 in an easy-to-understand manner. This FIG. 3 shows the left mark 17 and right mark 18 shown in FIG. 2 enlarged and the distance between both marks 17 and 18 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 and the other (right mark 18) overlap in the height direction. The amount of overlap determined by the bottom side 17a and the bottom side 8a of the right mark 18 is set to D. This overlap amount D is the width dimension d of the adjustment slit in the conventional adjustment pattern 2 shown in FIG.
, and defines the permissible range of angular deviation of the image sensor 5 in the Y-axis direction and around the lens axis.

FIG. 4 is a diagram showing a circuit configuration of a device that detects and controls a deviation in the mounting state of the image sensor 5 by reading the adjustment pattern shown in FIG. 3. In this control device 30, the image sensor 5 is digitized by an A/D converter 32 that converts an analog signal, which is an optical signal obtained by reading an adjustment pattern 32, into a digital signal. Random access to temporarily store signals
A memory (hereinafter referred to as RAM) 33 and a read-only memory (hereinafter referred to as
ROM) 34, a central processing unit (hereinafter referred to as CPU) 35 that compares and examines the digital signal with the theoretical value and generates a control signal, and this CPU 35.
and a memory 36 for storing operation support data. This detection device 30 is connected via an input/output interface 37 to a panavi setter 38, an air cylinder 39, a sensor 40,
It is connected to pulse motors 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 5 is attached to the mounting board 4. The image sensor 5 reads the adjustment pattern 32, photoelectrically converts the optical signal into an analog electrical signal, and sends it to the A/D converter 32. A/
The D converter 32 converts the analog signal sent from the image sensor 5 into a digital signal, and this digital signal is stored in the RAM 33 as image data. An example of the image data stored in this RAM 33 is shown in FIG. 2b. Next, CPU35
Read image data and reference data from RAM33 and ROM34, compare both data and perform X
The deviations in the axis, Y-axis, and rotational direction are determined, and the pulse motors 20, 21, and 22 are controlled according to the respective deviations. In this control operation, first the positioning slit 1 in the center of the adjustment pattern 32 is
4, move the lens 3 in the axial direction, calculate the amount of deviation in the X-axis direction with the CPU 35 in a temporary focus state, generate a signal for controlling the pulse motor 21, and move the image sensor 5 in the X-axis direction. .

Next, left and right marks 1 are used to detect deviation in the Y-axis direction and/or deviation in the axial direction of the lens 3.
Count the number of bits when reading and scanning 7 and 18. That is, in FIG. 3, when the image sensor 5 performs reading in the main scanning direction, the two-dot chain line S ₁
If reading is performed along the scanning line shown in , this reading scanning line _S1 is within the overlap amount D of the left and right marks 17 and 18, so the deviation in the Y-axis direction and around the lens axis is zero. or within the acceptable range. This state is uniquely determined by calculating the number of bits read by the image sensor 5 from the left and right marks 17 and 18. Therefore, the number of read bits in image data is
If the reading scanning state of _S1 is determined by reading out the theoretical value from the ROM 33 and calculating the theoretical value from the ROM 34, the image sensor 5 does not require Y-axis adjustment or rotational adjustment.

On the other hand, in the same reading scan as described above, if reading is also carried out along _the scanning line indicated by the two-dot chain line _S2 in FIG. The reading scanning angle and the deviation in the Y-axis direction are uniquely determined by calculating the number of bits read in the left and right marks 17 and 18 by the image sensor 5. Therefore, the CPU 35 reads the number of read bits in the image data from the RAM 33 and calculates the theoretical value.
By reading from the ROM 34 and performing arithmetic processing, the amount of deviation in the Y-axis direction and the amount of rotational deviation of the image sensor 5 are determined, and based on this, the CPU 35
A control signal is generated. This control signal controls the operation of the pulse motors 20 and 22, and based on this, the image sensor 5 is moved in the Y-axis direction and rotational direction. In such image sensor movement adjustment, the image sensor 5 is moved by the pulse motors 20 and 22, so that the positional accuracy of the image sensor 5 can be as high as ±5 μ.

FIG. 5 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, the adjustment pattern 45 has two white marks 26, 27, 2 at each end.
8 and 29 are displayed. In this embodiment, the marks 26, 27, 28, 29 are all formed in a triangular shape. Mark 26,2 on the left
7, 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, looking at marks 28 and 29 on the right, the rightmost mark 2
The marks 9 and 9 have their apexes facing up, and the mark 28 next to it has their apexes facing down, so that they are upside down. The bases of the marks 26 and 29 are aligned on the same horizontal line in the adjustment pattern 45, and the bases of the marks 27 and 28 are also aligned on the same horizontal line in the adjustment pattern 45. Furthermore, the set of marks 26 and 29 and the mark 27,
As in the first embodiment, the set 28 is set in a positional relationship such that there is an overlap in the height direction between one set and the other, and the bottom sides 26a, 29a of one set are connected to the other set. The base 27a of the set of
The amount of overlap determined by 28a is set to D, which defines the allowable range of angular deviation of the image sensor 5 in the Y-axis direction and around the lens axis. Note that the adjustment pattern of this embodiment also includes a positioning slit 14 and a focus adjustment slit gathering portion 16 similar to those in the first embodiment.

When the adjustment pattern 45 having such a configuration is used in an optical adjustment device, unlike in the first embodiment, the number of bits of the marks 26, 27, 28, and 29 changes when the image sensor 5 reads and scans. It is possible to detect the positional deviation of the image sensor 5 in the Y-axis direction and the angular deviation around the lens axis without calculating. That is, the image sensor 5
Whether or not the mark 26, 27, 28, 29 has been read is indicated by an on or off signal, and if all the marks 26, 27, 28, 29 are read (on for all marks), It is determined that the image sensor 5 is correctly installed. For example, when only the marks 26 and 29 are on, it is determined that the image sensor 5 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 5 is performing a reading operation below the normal position. Furthermore, when the marks 26 and 28 are on, the image sensor 5 moves downward to the right with respect to the adjustment pattern.
When the marks 27 and 29 are on, it is determined that the reading operation is performed upward to the right. Furthermore mark 26,2
When 8 and 29 are on, the image sensor 5 is shifted upward from the normal position and the reading operation is performed downward to the right. This makes it clear that the image sensor 5 is installed in various ways. Therefore, the operator can finely adjust the mounting position of the image sensor 5 while observing the on or off state of each mark 26, 27, 28, 29, thereby making the work of mounting the image sensor 5 easier. .

In addition, in the above first and second embodiments, Y
Although we have shown an example in which the mark for detecting axial deviation and rotational deviation around the lens axis is triangular, the shape of the mark is not limited to a triangle, for example, a trapezoid, or any other shape starting from the top. Any material may be used as long as the width gradually increases toward the bottom.

Effects of the Invention As explained above, according to the present invention, an adjustment pattern having marks of a predetermined shape on both ends is installed at the adjustment pattern installation position of the optical system adjustment device,
Calculation processing is performed based on the read output of this adjustment pattern to determine the installation error of the image sensor, so the installation adjustment work of the image sensor can be automated, and high-precision installation is possible. The effect of this can be obtained.

[Brief explanation of drawings]

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, and FIG. Figure b is an output waveform diagram when the above adjustment pattern is read by the image sensor, Figure 3 is an explanatory diagram showing the reading scanning state of the image sensor with respect to the mark of the adjustment pattern shown in Figure 2a, and Figure 4 is A block diagram of a control circuit that performs position adjustment control of the image sensor based on pattern information read by the image sensor, FIG. 5 is a schematic diagram of a second embodiment of the adjustment pattern used in the optical system adjustment device of the present invention, FIG. 6 is a schematic configuration diagram of a conventional optical system adjustment device, and FIG. 7 is a diagram of an adjustment pattern used in the conventional optical system adjustment device. 1... Light source, 2, 32, 45... Adjustment pattern, 3... Lens, 4... Mounting board, 5... Image sensor, 17, 18, 26, 27, 28, 2
9... Mark, 20, 21, 22... Pulse motor.

Claims (1)

[Claims] 1. An adjustment pattern installed on a 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 this mounting board,
It has a pulse motor that rotates to adjust the mounting position of the image 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 is adjusted to the position of the image sensor. A mark is installed corresponding to the light receiving line, and has a top and a bottom at both end portions, and has a shape that gradually expands from the top to the bottom, the top and the bottom being in an upside-down relationship with each other. An optical system adjustment device for an image reading device, characterized in that the optical system adjustment device is displayed as follows.