JPH0553360U - Scan output stabilizer for image input device - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention is used as an image input device for identifying the surface state of a scanning object such as a printed circuit board.
Regarding a device for stabilizing a scanning output in an optical device equipped with a D line sensor, a scanning start pulse for a CCD line sensor and a lighting pulse of a light source are controlled so as not to be influenced by a moving speed of an optical device or a scanning object,
It is an object of the present invention to provide a scanning output stabilizing device of an image input device that can obtain stable brightness in a CCD line sensor. A surface state of the scanning object is identified by obtaining image data by scanning reflected light of a light beam emitted from a light source onto the scanning object at a predetermined angle with a camera composed of a CCD line sensor and a lens. An image input device, wherein the light source is a high-intensity LED 21
This is because the LED driver 22 for synchronizing the start of lighting of No. 1 and the start of scanning of the CCD line sensor 6a is provided.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a device which is used as an image input device for identifying the surface state of a scanning object such as a printed circuit board and stabilizes the scanning output in an optical device having a CCD line sensor.

[0002]

[Prior Art]

 Conventionally, an optical image input device as shown in FIGS. 3 to 6 has been known as an image input device for inspecting the presence or absence of mounting components mounted on a printed circuit board as a scanning object. There is. That is, the printed circuit board surface 2 on which the mounting component 1 is mounted is irradiated with light from a light source (for example, a high-intensity LED or a halogen lamp) 3, and a part of the irradiated light is blocked by the light shielding plate 4 so that the shade 5 is shielded. The camera 6 is focused through the mirror 7 at a point slightly formed in the shade 5 after being formed. As shown in FIG. 4, the height t from the printed circuit board surface of the intersection of the light source 3 and the optical axis 8 of the camera is about 0.3 mm.

Then, the printed board or the optical device including the camera and the light source is moved relatively, and when there is the mounted component 1 having a predetermined height or more, the irradiation light is reflected, and as shown in FIG. This is scanned by the CCD line sensor 6a of the camera 6, and the intensity of the light and darkness is A / D converted via the video amplifier 9 into digital data of 64 gradations, which is read into the image memory 11 and then by the value calculator 12. The CPU 13 determines the process based on the comparison data of the binarized good printed circuit board, and displays the result of good or bad on a display means such as a printer or a display.

[0004]

[Problems to be solved by the device]

 However, in the above-described optical device of the image input device, since the light source 3 for irradiating the scanning object 2 is constantly illuminated, the speed of the moving device (not shown) for moving the optical device (or the printed circuit board) is set. If there is a change in the image data, the image data is taken in every movement of a fixed distance by the pulse from the encoder provided on the rotating shaft of the moving device. Therefore, the time of the interval of scanning by the CCD line sensor 6a is increased. change.

Therefore, there is a case where the integration time for which the reflected light is incident on the CCD line sensor 6a is changed, and the white level value is also changed due to the change in the amount of charges accumulated therein, and the image data may be different. There were flaws.

The present invention has been made in view of the above problems, and controls the scanning start pulse and the light source lighting pulse for the CCD line sensor so as not to be affected by the moving speed of the optical device or the scanning object. It is an object of the present invention to provide a scanning output stabilizing device of an image input device that can obtain stable brightness in a CCD line sensor.

[0007]

[Means for Solving the Problems]

 The gist of the present invention to solve the above problems and achieve the above object is to scan the reflected light of a light beam emitted from a light source at a predetermined angle on a scanning object with a camera composed of a CCD line sensor and a lens. An image input device for identifying the surface condition of the object to be scanned by obtaining image data, wherein the light source is a high-intensity LED, and the timing of starting lighting of the high-intensity LED and scanning start of the CCD line sensor is determined. It consists in providing the LED driver which synchronizes.

[0008]

[Action]

 According to the scanning output stabilizing device of the present invention, since the scanning start timing of the CCD line sensor and the lighting timing of the high brightness LED are synchronized, the reflected light entering the CCD line sensor when the high brightness LED is lit for a certain period of time. Is constant. As a result, the CCD line sensor is not affected even if the moving speed of the scanning object or the optical device changes.

[0009]

EXAMPLES Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a scanning output stabilizing device according to the present invention. FIG. 2 is an explanatory view showing a timing chart of the CCD line sensor and the high brightness LED similarly. In the figure, reference numeral 20 is an output stabilizer, 21 is a high-brightness LED, 22 is an LED driver, and 23 is a clock generator.

As shown in the block diagram of FIG. 1, the scanning output stabilizing device 20 of the present invention uses a high-brightness LED 21 capable of high-speed response as a light source 3 of the related art, and a high-luminance LED 21 and a clock generator 23. The LED driver 22 is interposed between the two.

In the CCD line sensor 6a and the high-brightness LED 21, the scanning in the main scanning direction and the lighting timing are synchronized. The state of this synchronization is shown in Fig. 2.

As described above, according to the scanning output stabilizing device 20 of the present invention, the scanning device 2 includes the camera 6 and the high-intensity LE D21 in one direction or two directions with respect to the scanning object 2 by a moving device (not shown). Move the optics at the same time.

Then, the high-brightness LED 21 is lit for a certain period of time by the timing from the clock generator 23 by the camera moving pulse from the moving device, and the CCD line sensor 6a scans the reflected light from the scanning object 2. , Image data is fetched and written in the image memory. In the CCD line sensor 6a, the high-brightness LED 21 is turned on for a certain period of time, so that a certain amount of reflected light is accumulated.

The camera moving pulse is obtained by an encoder provided on the moving rotary shaft of the moving device. Therefore, even if the moving speed of the moving device changes, the image data is fetched by the pulse signal from the clock generator 23 every fixed number of camera moving pulses, so that the image data is always taken at a fixed distance interval. Is taken in.

As described above, even if the moving speed of the moving device changes and the time interval for capturing image data by the CCD line sensor 6a becomes longer or shorter, the high-brightness LED 21 always scans the CCD line sensor 6a. Since the light is turned on at the same time as the start and is not turned on for a certain period of time, the amount of reflected light from the scanning object entering the CCD line sensor is constant.

In the above-described embodiment, the optical device of the image input device is moved with respect to the scanning object 2, but the optical device is of course fixed in position so that the scanning object can be moved in one or two directions. It is the same even if moved.

[0017]

[Effect of the device]

 As described above, the scanning output stabilizing device of the image input device according to the present invention scans the reflected light of the light beam emitted from the light source to the scanning object at a predetermined angle with the camera including the CCD line sensor and the lens. An image input device for identifying a surface state of the scanning object by obtaining image data by using the high-luminance LED as a light source, and starting the lighting of the high-luminance LED and the scanning start of the CCD line sensor. Since the LED driver for synchronizing the timing is provided, even if the moving speed of the moving device changes during the execution of the scanning, the integration time for which the reflected light is scanned by the CCD line sensor becomes constant, and the scanning target object is scanned. It is possible to eliminate the influence of the change in the relative moving speed. In this way, the identification performance of the image input device in capturing the image data is improved, and the reliability is increased.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a scanning output stabilizing device in an image processing unit according to the present invention.

FIG. 2 is an explanatory diagram showing a timing chart of a CCD line sensor and a high brightness LED in the same manner.

FIG. 3 is an explanatory diagram showing a scanning unit of an image input device according to a conventional example.

FIG. 4 is an explanatory diagram when there are no mounted parts.

FIG. 5 is an explanatory diagram when there are mounted components.

FIG. 6 is a block diagram of an image processing unit of an image input device according to a conventional example.

[Explanation of symbols]

20 output stabilizer, 21 high brightness LED, 22 LE
D driver, 23 clock generator.

Claims (1)

[Scope of utility model registration request] 1. A surface condition of the object to be scanned by scanning reflected light of a light beam emitted from a light source onto the object to be scanned at a predetermined angle by a camera including a CCD line sensor and a lens to obtain image data. Is an image input device for identifying a high-luminance LED as the light source,
A scanning output stabilizing device for an image input device, which is provided with an LED driver for synchronizing the start of lighting of D and the start of scanning of the CCD line sensor.