JPH05285U - Laser marking device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a laser marking device capable of performing reliable inspection with a relatively simple structure. [Structure] When an ultrasonic Q-switch laser 11 and an ultrasonic Q-switch laser beam emitted from the ultrasonic Q-switch laser 11 are applied to a workpiece 13, the ultrasonic wave is generated inside the workpiece 13 accordingly. The laser marking device includes an ultrasonic sensor 14 for detecting an ultrasonic wave to be generated, and a comparator 16 for comparing the output level of the ultrasonic sensor 14 with a predetermined threshold level after amplifying the output level as necessary.
When the output level of the ultrasonic sensor 14 does not exceed the predetermined threshold level, it is determined that the marking was not performed properly.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a laser marking device for marking characters and symbols with laser light, and more particularly to a laser marking device capable of inspecting a processing state of laser marking.

[0002]

[Prior Art]

 When characters or symbols are marked on a product using a laser marking device, inspection is performed to check the quality of the marking. A typical inspection that has been performed in the past is visual inspection using an optical instrument such as a microscope for all or a part of processed products. Further, for example, in the case of an automated line, a method of performing inspection by using a pattern recognition device in a post process of laser marking is also adopted. In this method, a pattern for laser marking is registered in the pattern recognition device, and the quality is judged by comparing it with the pattern marked on the workpiece.

[0003]

[Problems to be solved by the device]

 Among such conventional inspection methods, the visual inspection method has a problem that the inspection result varies depending on the degree of proficiency of the operator who performs the inspection. Further, in the case of inspection using a pattern recognition device, the configuration of various devices required for inspection such as the pattern recognition device and the positioning mechanism of the workpiece is complicated, and it is necessary to install these devices. There was a problem that it required space.

Therefore, an object of the present invention is to provide a laser marking device capable of performing a reliable inspection with a relatively simple structure.

[0005]

[Means for Solving the Problems]

 In the present invention, when the ultrasonic Q-switch laser and the ultrasonic Q-switch laser light emitted from the ultrasonic Q-switch laser are applied to the workpiece for marking, the workpiece is correspondingly irradiated with the ultrasonic Q-switch laser light. An ultrasonic sensor that detects the ultrasonic waves generated inside, a comparison unit that amplifies the output level of this ultrasonic sensor as necessary, and then compares it with a predetermined threshold level, and laser marking based on the comparison result of this comparison unit. And a discriminating means for discriminating the quality of processing of the workpiece in the laser marking device.

That is, in the present invention, when the ultrasonic Q-switch laser light is applied to the workpiece for marking, the ultrasonic wave generated inside the workpiece is measured by the sensor according to the irradiation, and the output is output. When the level is lower than the predetermined value, it is determined that the marking was not performed normally, and the predetermined control such as the operation stop of the laser marking device is enabled.

[0007]

【Example】

 Hereinafter, the present invention will be described in detail with reference to embodiments.

FIG. 1 shows the configuration of a laser marking device according to an embodiment of the present invention. This laser marking device includes an ultrasonic Q-switch laser 11. The laser beam emitted from the ultrasonic Q-switch laser 11 passes through the optical system 12 and is applied to a desired position on the workpiece 13 to perform laser marking. An ultrasonic sensor 14 is arranged in the vicinity of the work piece 13 so that the ultrasonic wave generated inside the work piece 13 by the irradiation of the ultrasonic Q-switch laser light is detected.

The detection signal of the ultrasonic sensor 14 is input to the amplifier 15 and amplified to a predetermined level. The output of the amplifier 15 is input to the comparator 16. The comparator 16 synchronizes the output of the amplifier 15 with a predetermined signal in synchronization with a control signal input from the control unit 17 for controlling the ultrasonic Q switch laser 11 and the optical system 12 to the ultrasonic Q switch laser 11. The threshold level is compared and the comparison result is input to the control unit 17.

FIG. 2 is for explaining the operation of each part of the laser marking device having such a configuration. The operation of the laser marking device during marking will be described with reference to this drawing.

First, the control unit 17 generates the control signal 21 at a predetermined cycle as shown in FIG. The control signal 21 is input to both the ultrasonic Q-switch laser 11 and the comparator 16. The ultrasonic Q-switch laser 11 outputs the ultrasonic Q-switch laser light in synchronization with this control signal 21. FIG. 2B shows the waveform of the ultrasonic Q-switched laser light 22 output from the optical system 12. The workpiece 13 is sequentially processed by the ultrasonic Q-switch laser light 22, and the ultrasonic waves 23 are generated as shown in FIG. 2C depending on the degree of the processing. The ultrasonic wave 23 is detected by the ultrasonic sensor 14 and amplified by the amplifier 15. As a result, as shown in FIG. 2D, the ultrasonic detection signal 24 corresponding to each processing is input to the comparator 16.

The comparator 16 compares the signal level of these detection signals 24 with a predetermined threshold level TH set in advance, and when the detection signal 24 exceeds the threshold level TH in synchronization with each control signal 21. Holds its comparison output 25 (FIG. 2e) at L (low) level. When the comparative output 25 is held at the L level, it means that the respective markings performed up to that point are normally performed.

On the other hand, when the marking on the work piece 13 is not normally performed, the ultrasonic waves 23 are not normally generated and the level thereof is lowered. In this case, the peak value of the detection signal 24 does not exceed the threshold level TH. The third waveform from the left in FIG. 2D represents such a state. Thus, when the detection signal 24 does not exceed the threshold level TH, the comparator 16 changes the comparison output 25 to the H (high) level. The control unit 17 receives the change in the comparison output 25 and stops the operation of the laser marking device. The waveform shown by the broken line in FIG. 2A represents a state in which the control signal 21, which should be output at a predetermined timing, was not output due to the operation stop of the laser marking device.

As described above, in the laser marking apparatus of this embodiment, by comparing the level of the ultrasonic wave generated by the workpiece during marking with a predetermined threshold value, it is determined whether or not the marking is normally performed. It will be.

FIG. 3 shows a modification of the present invention. In the laser marking device of this modification, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be appropriately omitted.

In the laser marking device of this modification, the detection signal 24 output from the amplifier 15 is input to the comparator 31. In the comparator 31, the control signal 21 output from the control unit 32 is supplied to the ultrasonic Q-switch laser 11 and also to the comparator 31. The control signal 21 is for notifying the timing at which marking is performed as in the previous embodiment.

In this modification, the threshold value setting information 33 as a digital value is output from the control unit 32 and supplied to the D / A converter 34. The D / A converter 34 converts this into an analog value and supplies it as a threshold level 35 to the comparator 31. That is, in the laser marking apparatus of this modified example, the threshold level is not fixedly set in the comparator 31, but an arbitrary threshold level TH 'is set by the threshold setting information 33 given from the control unit 32. It is like this. The comparator 31 compares the threshold level TH 'with the signal level of the detection signal 24. If the threshold value is not exceeded, the workpiece is not normally marked as in the previous embodiment. As a result, the operation of the laser marking device will be stopped.

However, in the laser marking device of this modification, the threshold level TH ′ can be freely adjusted on the control unit 32 side, so that it can be changed to an appropriate value depending on the type of product. The inspection target of the laser marking device can be expanded to a wide range.

[0019]

[Effect of the device]

 As described above, according to the present invention, the ultrasonic waves generated inside the workpiece at the time of marking are measured by the sensor, and it is decided whether or not the marking is normally performed according to the output level. The effect is that the quality can be judged at the same time as the marking. Moreover, unlike the conventional method, it is not necessary to rely on visual inspection or to use a complicated inspection device, so stable and highly reliable inspection can be performed, and labor saving and downsizing of equipment can be realized. it can.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a laser marking device according to an embodiment of the present invention.

FIG. 2 is a timing chart showing the operation of this laser marking device.

FIG. 3 is a block diagram showing a circuit configuration of a laser marking device in a modified example.

[Explanation of symbols]

 11 Ultrasonic Q-Switch Laser 13 Workpiece 14 Ultrasonic Sensor 16, 31 Comparator 17, 32 Control Unit 23 Ultrasonic 24 Detection Signal 34 D / A Converter 35 Threshold Level

Claims (1)

[Claims for utility model registration] 1. When an ultrasonic Q switch laser and an ultrasonic Q switch laser beam emitted from the ultrasonic Q switch laser are applied to a workpiece, An ultrasonic sensor for detecting ultrasonic waves generated inside the workpiece, a comparing means for comparing the output level of the ultrasonic sensor with a predetermined threshold level, and a workpiece for laser marking based on the comparison result of the comparing means. A laser marking device, comprising: a discriminating means for discriminating whether or not the processing of the above is good or bad.