JPS59183350A - Surface inspecting apparatus - Google Patents

Abstract

PURPOSE:To enable the simultaneous inspection of a pinhole in distinction from a surface defect, by simple constitution wherein a reflective member such as a mirror is arranged in opposed relationship. CONSTITUTION:A sensor part 12 equipped with a laser beam emitting part and a beam receiving part for receiving reflected beam from a plate 1 to be inspected and a mirror 11 are arranged in opposed relation to each other so as to interpose the plate 1 to be inspected therebetween. In this case, weak reflected beam (a) due to interference in the defect part of the plate 1 to be inspected and strong reflected beam (b) through a pinhole and the mirror 11 are respectively received in good separability by the sensor part 12. By this mechanism, the pinhole can be simultaneously inspected in distinction from a surface defect by simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface inspection device that inspects the surface and pinholes of a sheet member, such as a steel plate, using a light beam such as a laser beam.

A conventional device of this type is shown in FIG. In the figure, (ri) is the board to be inspected, (2) is a projector made up of an incandescent lamp, fluorescent lamp, etc. that irradiates this board (υ), and (3) is a receiver made of a solar cell, photodiode, etc. , this light receiver (3) is installed opposite to the projector (2) via the inspection plate (1).(4) is the light receiver (
This is a signal processing device that processes the light reception signal (-signal) output from 3) and detects pinholes in the board to be inspected (1). Part (5) is formed.(6) is a light projector that scans and irradiates the board to be inspected (1) with a light beam (laser beam), and (7) is a light projector that scans and irradiates the board to be inspected (1) with a light beam (laser beam). A light receiver (8) that receives the reflected light beam reflected from the inspection plate (1) processes the light output from this light receiver (7) and detects defects (scratches) on the surface of the inspection plate (1). .

This is a signal processing unit that detects the presence or absence of dirt (dirt, etc.).
Surface inspection s(9) are formed from L et al matrices (6) to (August).

Next, the operation will be explained. In Figure 1, the board to be inspected (
1) is transported at a predetermined speed, and the plate to be inspected (1) is continuously illuminated by a light projector (2).

Now, the pinhole in the board to be inspected (1) is illuminated by the projector (2).
When the irradiated light reaches the irradiation area, it passes through the pinhole and enters the light receiver (3), where it is received. This receiver t3
) 'i:' The light that is received and passes through the fs pinhole is converted into an electrical signal according to the light level by a photoelectric conversion element such as a solar cell or a photodiode in the receiver (3), and then sent to a signal processing device (April The signal input to the signal processing device (4-pin) is processed by an amplifier circuit, a comparator, etc., and pinholes are detected.

On the other hand, the surface inspection of the board to be inspected (1) is performed by scanning a light beam of a light projector (6) and by a light receiver (7) that receives the reflected light. In other words, if there is a defect on the surface of the plate to be inspected (1), the reflected light level decreases due to the disturbance of the diffraction (reflection) pattern of the light beam at the defective part, and this decrease is reflected from the light receiver (7). An electric signal corresponding to the signal is output and input manually to the signal processing device 8).

The electrical signal input to the signal processing device (8) is subjected to processing such as amplification and comparison to detect surface defects.

Since the conventional surface inspection equipment is configured as described above, it has disadvantages such as the cost of the equipment becoming expensive if the equipment is installed separately for the surface inspection and pinhole inspection of the board to be inspected. there were.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional devices.It includes a sensor section consisting of a light projecting section and a light receiving section, and a sensor section that reflects a light beam emitted from the light projecting section to the light receiving section. By arranging the parts facing each other with the board to be inspected in between, surface defects and pinholes on the board to be inspected can be detected at the same time.
It is an object of the present invention to provide a surface inspection device that can separate and detect the surface, save installation space, and reduce the cost of the device. .

An embodiment of the present invention will be described below with reference to the drawings. Second
In the figure, θη (J is a mirror assembled at a specific angle, @ is a sensor unit consisting of a laser light emitting unit and a light receiving unit including a photoelectric conversion element such as a photomultiplier tube, and a mouse is a sensor unit. This is a signal processing device that receives an electrical signal corresponding to the received light level from (6) and performs various electrical signal processing.

This operation will be explained next. The laser beam emitted from the laser tube inside the sensor unit 0 is focused into a predetermined shape by a lens system, mirror, 4-magnetic vibrating mirror, rotating mirror, etc., and is directed onto the inspection target board (1) perpendicular to the direction of movement. scanned in the direction. The laser beam reflected by the plate to be inspected (1) is focused by an optical fiber or lens, converted into an air signal by a photomultiplier tube, etc., and sent to a signal processing device. However, within the signal processing device, the signal is processed by amplification, waveform shaping, comparator, etc. Here, the mirrors 0η are combined in the correct shape as shown in Fig. 8 with respect to the projection angle of the laser beam onto the plate to be inspected (1), and the laser beam passing through the pinhole of the plate to be inspected (1) Beam〃) Sensor unit 0 light receiving unit (The angle is set so that it is reflected. In the case of this figure 3, the combination angle of mirror C1υ is the value obtained by subtracting the beam projection angle a0 from 90 degrees. It is.

As in this embodiment, in the surface inspection method that receives specularly reflected light, the signal in the signal processing device for a normal surface is as shown in Fig. 4 for one scan of the laser beam. b) There is no signal, and the electric signal waveform becomes a uniform bell.
If there is a surface defect, the laser beam's folding pattern will be disrupted in each defect, so the signal level will be low and the word (a) will appear.) If there is a pinhole inspection, the mirror As the reflected light from Gυl is added, its signal level () becomes higher and the signal (b) appears. It is easy to separate and detect the signals (a) and (b) shown in (a) and (b), and with this device, surface inspection and pinhole inspection can be done immediately.

In the above embodiment, it is possible to receive light passing through a pinhole by changing the configuration of the mirror (II) for the specular reflection light reception method (described in Section 8), but also for the diffuse light reception method. In this case, the signal is in the same direction as the surface defect signal and is expressed as "C," but it is not possible to separate the surface defect signal and pinhole signal based on the signal level difference. - Yes, the same effect as in the above embodiment is achieved.

As described above, according to the present invention, a reflecting member such as a mirror is disposed facing the conventional surface inspection device consisting of an XL light projecting section and a light receiving section, and the light passing through the pinhole is reflected by this reflecting member. Moreover, the surface inspection and pinhole inspection of the blue plate to be inspected can be carried out at the same time.In addition, there is an effect that the apparatus can be made smaller and less expensive.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional surface inspection device, FIG. 2 is a block diagram of a surface inspection device according to an embodiment of the present invention, FIG. 3 is a side view showing the structure of the mirror in FIG. 2, and FIG.
The reason for this is an operational waveform diagram for explaining the operation within the signal processing section of FIG. aυ゛°゛Mirror,...sensor section In the drawings, the same reference numerals indicate the same or equivalent parts. Agent: Nij Masuo Oiwa Figure 1

Claims (1)

[Claims] a sensor section provided on one side of the board to be inspected and configured with a light projecting part that emits a ζζ light beam for the board to be inspected, and a light receiving part that receives reflected light of the light beam emitted from the light projecting part; and is disposed on the other side of the board to be inspected and facing the sensor unit, and diffracts and reflects the light beam from the light projecting unit that has passed through the pinhole of the board to be inspected, and directs the reflected light to the pin of the board to be inspected. A surface inspection device including a reflecting section that allows the light to pass through the hole and enter the light receiving section.