JPH08307741A - Image pickup device - Google Patents

Abstract

PURPOSE: To image-pick up an electronic component at high speed and with a low cost by constructing an electronic image pickup device by using one line sensor, not depending on the sampling frequency of a transmission system, processing system, etc., and without generating the dispersion of brightness of an image-picked up image. CONSTITUTION: Obtained image data is charged with a photodetector 21 in the line sensor 100, and an electric charge is stored in a CCD shift register 22. Image scanning is performed by switching a timing acquired from the outside form the input port 27 of an interface connector 30 by a selector, and selecting whether the scanning is performed by either of timing control circuits 23a, 23b. A selected timing control device 23a or 23b scans the CCD shift register 22 by a clock generated in a clock generator 25 according to an inputted scan timing. A scanned electric charge is transferred to the output part 28 of the interface connector 30 via an A/D converter 26 as image data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component recognition system mounted on an industrial automatic facility or the like, and more particularly to an image pickup device thereof.

[0002]

2. Description of the Related Art FIG. 10 shows a typical example of a conventional image capturing system in a component recognition system mounted on an industrial automatic facility or the like. Description will be given below with reference to the drawings. FIG. 10 shows a block configuration of the entire component recognition system. As components, 10 is a target electronic component, 1
1 is a component holding nozzle, 12 is a moving device for moving the component holding nozzle 11, 13 is an illuminating device, 14a is a first camera having a lens and a line sensor inside, and 14b is a second camera having a lens and a line sensor inside. Camera, 15a
Is a transmission line for transmitting the first camera output, 15b is a transmission line for transmitting the second camera output, and 16 is an image processing device.

FIG. 11 shows the relationship between the target electronic component 10, the lens and the light receiving element, wherein 21 is a light receiving element and 43 is a lens. FIG. 12 shows the line sensor 10 in the camera 14.
0 indicates, 21 is a light receiving element, 22 is a CCD shift register, 23 is a timing control circuit, 25 is a clock generator, 27 is an input port, 28 is an output port, 30
Is an interface connector. The relationship and operation of each of the components of the conventional image capturing apparatus including the above components will be described. In FIG. 10, the target electronic component 10 gripped by the component gripping nozzle 11 and illuminated by the illumination device 13 with a sufficient light amount for exposure of the camera.
Is placed on the cameras 14a and 14b to move the moving device 12
Move by. The cameras 14a and 14b having the line sensor 100 therein capture the target component 10 line by line, and the obtained image data of each line is transmitted to the image processing device 16 via the transmission lines 15a and 15b. The processing device 16 combines the data obtained for each line into one aggregate, and processes it as part data.

Here, the first camera 14a and the second camera 14b having different specifications are used. For example, in FIG. 11, the set distance between the lens 43 and the target component 10 and the lens 43 to the light receiving element 21 are used. And the number of light receiving elements 21 arranged.

As a result, the first camera 1 having different specifications
By switching between 4a and the second camera 14b,
The image field size, the image resolution, etc. can be changed according to the size of the target component. Image data for each line of the target electronic component 10 is acquired by making the scanning direction of the target component 10 orthogonal to the arrangement direction of the light receiving elements 21 in the line sensor.

The image data obtained in FIG. 12 is charged in the light receiving element 21 of the line sensor 100, and the charge is stored in the CCD shift register 22. The stored image data is input to the input unit 27 of the interface connector 30.
The timing control circuit 23 receives a timing obtained from the outside, and the CCD shift register 2 is driven by the clock generated by the clock generator 25 in accordance with the received timing.
2 is scanned and the image data is transferred to the output port 28 in the interface connector 30. Here, the illuminating device 13 needs an appropriate amount of light with which the light-receiving element 21 can be charged with electric charges, and particularly when the target electronic component 10 is scanned at high speed, the amount of light is increased to illuminate in order to eliminate the shortage of the CCD charging time. There are many.

[0007]

By the way, in the above technique, when the target electronic component 10 is scanned at high speed regardless of the set resolution, the electric charge of the light receiving element 21 may become insufficient. That is, when all the CCD shift registers 22 in the line sensor 100 are scanned regardless of the size of the target electronic component 10, if the resolution becomes small, the charging time of the light receiving element 21 becomes short. Also, in order to increase the scanning speed of parts, the line sensor 1
If the CCD shift register 22 in 00 has a high scanning frequency, the transfer rate is limited by the upper limit of the transfer frequency from the line sensor 100 to the processing device and the sampling frequency of the processing device. Furthermore, when switching cameras depending on the size of the field of view, it is necessary to prepare two types of cameras having different specifications, which increases the cost.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide an image pickup device having high flexibility and low cost.

[0009]

In order to solve the above-mentioned problems, according to the present invention, one row or a plurality of rows of light receiving elements and a CC for transferring charges accumulated in the light receiving elements to an output section.
What is claimed is: 1. An image pickup device, comprising: a line sensor having a D register; one or a plurality of lenses; and a lighting device having one or a plurality of light sources. The electronic parts are
By moving the light receiving elements in a row or in a plurality of rows in a direction orthogonal to the image of the electronic component and varying the transfer range of the CCD register, or by changing the transfer range of the CCD register, or in the CCD shift register in the line sensor. It is characterized in that a buffer memory capable of storing electric charges is provided to capture an image of an electronic component.

[0010]

With this configuration, there is no variation in brightness due to insufficient charging time, and electronic components can be scanned at high speed regardless of the sampling frequency of the processing system and the set image resolution, and a low cost visual recognition system. Can be built.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The same components as those of the image pickup apparatus of the conventional example are denoted by the reference numerals and the description thereof will be omitted. FIG. 1 is a diagram showing the configuration of the line sensor according to the first embodiment of the present invention.

23a as a characteristic component in FIG.
Is a first timing control circuit, 23b is a second timing control circuit, 26 is an A / D converter, and 32 is a counter.

In the image pickup apparatus having the above-mentioned components, the image data obtained as shown in the conventional example is charged in the light receiving element 21, and the charge is stored in the CCD shift register 22. For image scanning, the timing control circuit 23a receives the timing obtained from the outside through the input port 27 of the interface connector 30, and the CCD shift register 22 is scanned by the clock from the clock generator 25 in accordance with the scanning timing. Image data of the scanned charges is transferred to the output port 28 in the interface connector 30 via the A / D converter 26.

Here, the A / D converter 26 outputs a digital signal, and in the case of analog signal output, the A / D converter 26 is not required unlike the conventional example. Here, the CCD shift register 22 is reset by the second timing control circuit 23b, and when the counter 32 counts up the clock obtained by the clock generator 25 and reaches the set arbitrary count number, CCD by the second timing control circuit 23b
The shift register 22 is reset. With this CCD
The scanning range of the shift register 22 can be made variable, and the transfer time can be shortened by minimizing the transfer data length.

2 to 5 show the CCD shift register 22.
In the example specifically showing the scanning range and scanning method of
Is a scan start signal from the first timing control circuit 23a,
Reference numeral 53 is a reset request signal from the second timing control circuit 23b, and 54a, 54b, 54c and 54d are CCD shift register scanning bit lengths. FIG. 2 shows a case where the CCD shift register 22 is entirely scanned from one direction.
For example, if the number of pixels of the CCD shift register 22 is 1024
, The CC according to the scan start signal 52
By transmitting the reset request signal 53 when 1024 pixels of the D shift register 22 are counted, C
All of the CD shift register 22 can be scanned. At this time, the scan bit length of the CCD shift register 22 is 54a. FIG. 3 shows a case where the CCD shift register 22 is scanned halfway. For example, if the reset request signal 53 is transmitted when the number of pixels of the CCD shift register 22 has been counted 512, half the scan bit length 54a of FIG. The length 54b can be selected. In addition, the line rate when the CCD shift register 22 is repeatedly scanned for one line at this time is, of course, as shown in FIG.
It is twice as much as the case.

Next, FIG. 4 shows a case where the CCD shift register 22 is divided into a plurality of parts for scanning, and particularly this drawing shows a case where the CCD shift register 22 is divided into two parts and scanned from the center. For example, the scanning is started at the 512th pixel and the 513th pixel of the CCD shift register 22.
A scanning start signal 52 is generated so as to scan left and right from the pixel position, a reset request signal 53 is transmitted when 512 pixels of the CCD shift register 22 divided into two are counted, and the CCD register 22 divided into two after transfer. By combining the data, all CCD shift registers can be scanned as in FIG. At that time, the scan bit length of the CCD shift register 22 (2 × 54
In b), the scan bit length 55a of FIG. 2 is the same, and the line rate can be doubled as compared with the case of FIG.

FIG. 5 shows a case in which the count-up number of the CCD shift register 22 in FIG. 4 is variable, and in particular, the scanning range is halved. When 256 pixels have been counted in the CCD shift register 22, the reset request signal 53 is transmitted to scan the CCD shift register 22 in the half range of FIG. 4, and the line rate is naturally doubled. The scanning bit length (2 × 54c) of the CCD shift register 22 is shown in FIG.
The scanning bit length is 54b, and the line rate can be doubled as compared with the case of FIG.

As described above, the line rate of the CCD shift register 22 can be made variable by making the scanning bit length of the CCD shift register 22 variable and performing scanning separately, and according to the visual field size and the image resolution. By selecting the scanning bit length and the division number of the CCD shift register 22, only the line rate can be changed with the same CCD scanning frequency. That is, the image data transfer frequency per line can be changed with the same CCD charging time. The component scanning speed is C as shown in FIG.
Since it is determined by the line rate and pixel resolution of the CD shift register, when the pixel resolution is set large, it may be necessary to use a camera capable of high-speed scanning or reduce the component scanning speed in order to obtain a sufficient CCD exposure time. Many. However, the above method makes it possible to obtain image data charged in the same CCD charging time at a constant component scanning speed regardless of the size and setting resolution of the target electronic component.

FIG. 6 is a diagram showing a configuration of the line sensor according to the second aspect. Here, the line buffer 31 is provided as a characteristic component. In this configuration, the CCD shift register 22 is scanned at all clock frequencies of the clock generator 25, and the output data is scanned by the A / D converter 26.
After being converted by, the data is stored in the line buffer 31. FIG.
5 and 16 show the structure of the line buffer.

FIG. 15 shows a structure in which the output data bit length can be made variable, and the buffering to the line buffer 31 is started by the START signal generated by counting up by the counter 32. Thereafter, after taking in an arbitrary bit length, the buffering of the line buffer 31 is completed by the RESET signal similarly generated by the counter 32.

With this configuration, the output data bit length can be made variable, unnecessary data transmission can be eliminated, and the data transmission time can be shortened, enabling high-speed online processing in the image processing system.

The configuration of FIG. 16 shows a configuration in which the output transmission speed is variable, and arbitrary image data scanned at high speed is temporarily stored in the line buffer 31. After that, the clock speed is changed by dividing the clock by the counter 32, and the image data is output from the line buffer 31 according to the converted clock.

Generally, it is difficult to increase the transmission speed of the transmission line 15 shown in FIG. 11 to several tens of MHz or more with an inexpensive hardware configuration. In addition, the processing speed of the image processing unit 16 is often limited. However, if the speed interface between the camera system and the transmission system is adopted like this configuration, it becomes possible to accurately transmit the image data without causing transmission distortion, and the processing speed of the image processing system is improved. It is also possible to match.

FIG. 7 is a diagram showing another embodiment constructed by combining claims 1 and 2. This configuration is a combination of FIG. 1 and FIG. 6, so that there is no difference in brightness between individual image data due to the difference in CCD charging time, and the components are independent of the transfer frequency or sampling frequency of the transfer system or processing system. The scanning speed can be optimized.

FIG. 8 shows an example of an apparatus for switching the magnification by using the half mirror according to the third aspect.
a and 41b are half mirrors, 42a and 42b are mirrors,
Reference numerals 43a and 43b are lenses, 44 is a rotary main shaft, 45 is a rotary shutter, and 46 is a pulse motor.

FIG. 9 shows the structure of a rotary shutter, and 47 and 48 are light entrance ports. Here, the light information of the electronic component 10 illuminated by the illumination device 13 is 41
It is divided into two by the half mirror 41a of a, one of them is branched to the lens 43a, and the other is branched to the lens 43b after the course is changed by the mirror 42a. The branched light information is condensed by the lenses 43a and 43b, one of which is directly changed and the other of which is changed in its course by the mirror 42b, and then reaches the shutter 45. If the shutter has the structure shown in FIG. 5, for example, by rotating the pulse motor 46 around the rotation main shaft 44, only one light is transmitted through the entrance port 46 or 47, and two-direction optical information is transmitted. One of them can be selected. After that, the selected optical information reaches the light receiving element 21 via the half mirror 41b.

With this configuration, it is possible to provide two or more light paths, and the magnification of the target component can be changed by changing the distance from the half mirror 41a to the mirror 42a or from the mirror 42b to the half mirror 41b, for example. Can be Although only a rotary shutter is shown as the shutter, if a half mirror having a waveguide structure capable of changing the light transmittance by changing the voltage is used as the half mirror 41a or 41b, the half mirror 41a or 41b is compared with the rotary shutter. It is also possible to change the light entry route at high speed. Further, as described in claim 4, it is possible to change the set magnification of the target component by using a zoom lens that is movable in the vertical direction with respect to the light receiving element.

FIG. 13 shows an example of the illuminating device 13 shown in claim 7. As constituent elements, 62 is an illuminating line of a symmetrical electronic component, 63 is a center point of the illuminating line, 61a, 61
Reference numerals b, 61c, 61d, 61e and 61f denote light source arrangement surfaces. Although not shown in FIG. 13, 61a, 61b, 6
Mirror-symmetrical with respect to 1c, the light source placement surfaces 61i, 61j,
The light source placement surfaces 61f, 61g, and 61h are attached to 61k and 61c, 61d, and 61e in mirror symmetry. Here, one or a plurality of LEDs or LDs each having an emission wavelength for which the sensitivity of the CCD line sensor is guaranteed is arranged on the light source placement surface 61, and the LEDs and LDs are attached at a plurality of steps as shown in FIG. . The respective light source arrangement surfaces 61 attached are arranged equidistantly with respect to the center point 63 of the illumination line 62 on which the target electronic component 10 is present, so that there is no difference in the amount of light depending on the angle. Further, the light amount correction circuit 64 corrects the light amount of each light source 61 according to the rule of the algorithm used for product recognition.

FIG. 14 shows an example of the light quantity correction circuit 64. As components, 65 is an interface connector, 66 is an input signal selector, 67 is an output signal selector, 68 is a control circuit, and 69a to 69m are photodiodes. Indicates.

As shown in the figure, photodiodes 69a to 69m are arranged in the respective light sources 61a to 69m, the output currents thereof are collected in the connector 65, and the output currents are transmitted in parallel to the selector 66. The selector 66 sequentially selects the output current and sends it to the control circuit 68 as an input signal. The received control circuit 68 generates a control signal under the set gain and transmits the control signal to the output selector 67. During this time,
The output selector 67 that receives the control signal operates in synchronization with the input selector 66, and outputs the control signal to any of the light sources 61a to 61m selected by the input selector 66. With this configuration, the light source 61a
It is possible to sequentially control the light amount of up to 61 m, and if the control circuit 68 has an independent gain, the light source 61a
It becomes possible to independently control ~ 61 m. In addition, the selector 66,
The same operation can be performed by preparing the control circuits 68 by the number of the light source arrangement surfaces without using 67.
It is also possible to control the forward current to the light source in a feedforward manner without using a photodiode for light amount correction.

Accordingly, by preparing in advance the optimum light amount and illumination angle for each component, the reflectance depending on the color and material of the target electronic component may be different, and the component recognition error rate due to irregular reflection caused by the surface condition may be increased. It can be minimized.

[0032]

As is apparent from the above description of the embodiments, according to the present invention, in a visual recognition system, an electronic component is imaged at a high speed regardless of the size of the target electronic component, and an image is formed by the difference in charge time. It is possible to prevent uneven brightness in an image, and at a low cost. Therefore, it can be used for automated equipment such as a mounting machine or an inspection machine.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a line sensor in an image pickup apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory view of a scanning range of a CCD register and a scanning method in the line sensor.

FIG. 3 is an explanatory view of a scanning range of a CCD register and a scanning method in the line sensor.

FIG. 4 is an explanatory diagram of a scanning range of a CCD register and a scanning method in the line sensor.

FIG. 5 is an explanatory view of a scanning range of a CCD register and a scanning method in the line sensor.

FIG. 6 is a configuration diagram of a line sensor in an image pickup apparatus according to another embodiment of the present invention.

FIG. 7 is a configuration diagram of a line sensor in an image pickup apparatus according to another embodiment of the present invention.

FIG. 8 is a configuration diagram of a magnification setting device in the image pickup device according to the embodiment of the present invention.

FIG. 9 is a configuration diagram of a mechanical shutter in the magnification setting device.

FIG. 10 is a configuration diagram of a conventional image pickup device.

FIG. 11 is a diagram illustrating a target component, a lens, and the like in the image capturing apparatus.
Explanatory diagram showing the relationship of light receiving elements

FIG. 12 is a configuration diagram of a line sensor in a conventional image pickup device.

FIG. 13 is a configuration diagram of an illumination device in the image pickup device of the present invention.

FIG. 14 is a circuit diagram of a light amount correction circuit in the image pickup device of the present invention.

FIG. 15 is a configuration diagram of a line buffer in the line sensor of the present invention.

FIG. 16 is a configuration diagram of a line buffer in the line sensor of the present invention.

FIG. 17 is an explanatory diagram of component scanning speed.

[Explanation of Codes] 10 Target Electronic Component 11 Component Gripping Nozzle 12 Moving Device 13 Lighting Device 14a, 14b Camera 15a, 15b Transmission Line 16 Image Processing Device 21 Photoreceptor Element 22 CCD Shift Register 23a, 23b, 23c Timing Control Circuit 24 Selector 25 Clock generator 26 A / D converter 27 Input port 28 Output port 30 Interface connector 31 Line buffer 32 Counter 41a, 41b Half mirror 42a, 42b Mirror 43a, 43b Lens 44 Rotating main shaft 45 Rotating shutter 46 Pulse motor 47 First Entry port 48 Second entry port 52 Scanning start signal 53 Reset request signal 54a, 54b, 54c, 54d CCD shift register scanning frequency 61a to 61m Light source 62 Illumination of target electronic components Center point 65 interface connector in 63 irradiating line 66 an input signal selector 67 outputs the signal selector 68 a control circuit 69a~69m photodiode 100 line sensor

Claims (7)

[Claims] 1. A line sensor having one or a plurality of rows of light receiving elements and a CCD register for transferring charges accumulated in the light receiving elements to an output section, one or a plurality of lenses, and an electronic component passing through or An image pickup apparatus comprising an illuminating device having one or a plurality of light sources for reflecting illumination, comprising means for moving the electronic component in a direction orthogonal to the one or a plurality of rows of light receiving elements, and the electronic device. An image pickup device comprising means for picking up an image of a part and means for varying a transfer range of the CCD register. 2. A line sensor having one or a plurality of rows of light receiving elements and a CCD register for transferring charges accumulated in the light receiving elements to an output section, one or a plurality of lenses, and an electronic component that is transmitted or An image pickup apparatus comprising an illuminating device having one or a plurality of light sources for reflecting illumination, comprising means for moving the electronic component in a direction orthogonal to the one or a plurality of rows of light receiving elements, and the electronic device. Means for imaging the parts, and the CCD in the line sensor
An image pickup device comprising a buffer memory capable of storing arbitrary charges in a shift register. 3. A plurality of half mirrors, a plurality of mirrors, and a plurality of shutters are provided between the light receiving element and the object, and two or more light traveling paths are provided. The image pickup device according to claim 2. 4. The image pickup device according to claim 1, wherein the lens in the line sensor is a zoom lens movable in the vertical direction of the light receiving element. 5. The image pickup device according to claim 3, wherein the shutter is configured to control the light transmittance by mechanically rotating a rotary plate having holes on its upper surface and side surfaces. . 6. A plurality of half mirrors and a plurality of mirrors are provided between the light receiving element and the object, the number of traveling paths of light is two or more, and the half mirrors have a waveguide structure by a photoelectric effect. The image pickup device according to claim 3, wherein the light transmittance is variable. 7. The image pickup device according to claim 1, wherein the lighting device illuminates the electronic component from a plurality of angles and variably controls a light amount.