JPS60250221A - Color defect inspecting device - Google Patents

Abstract

PURPOSE:To realize correction of unevenness of light quantity with a simple construction, by installing a memory storing an information controlling a light shutter means so as to control fluctuation of quantity of reflected light depending on a location of a specimen on which light is irradiated. CONSTITUTION:After arranging a beam of light from a source 31 into parallel beams by a series of lenses 33 through a group of light shutters 32, a specimen 44 is subjected to a vertical scanning at equal speeds through rotating mirror 37 and paraboloidal mirror 36. Further, an address signal corresponding to specimen 44 position showing commencement of scanning is given to a shutter controlling circuit 34 from an address signal generating circuit 35 by a starting signal generated by a photoelectric element 36a for generating starting signal. Further, a decision processing circuit 45 determines a position of irradiated beam by scan start signal and the specified clock signal. And, fluctuation of light quantity by difference of the irradiated light spot is measured preliminarily by a standard plate and the measurement is stored corresponding to the irradiated spot position in a memory in the processing circuit 45 and a group of shutters are driven for correction of unevenness of light quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a color defect inspection device for inspecting color defects in a sheet-like object.

BACKGROUND ART FIG. 1 is a block diagram of a conventional color defect inspection apparatus. Light such as xenon light and norogen light emitted from the light source 1 is passed through a one-rotation mirror 4 and a parabolic mirror 3.

The sheet-shaped object 6 to be inspected is scanned perpendicularly at a constant speed.

The light diffusely reflected in the 45° direction by the inspected object 6 is received by the optical fiber bundle 7 and cannot be guided to the integrating sphere 9. Integrating sphere 9 red filter 8. Blue filter 11. The green filter 10 separates the light into three primary color lights.

The three primary color lights are converted into electrical signals by photoelectric conversion elements 15, 13, and 12. Processing circuit] 4.

The electric signals converted by the photoelectric conversion elements 15, 13, and 12 are received, and the footing of one color is performed.

A pre-start operation is started by the processing circuit 14#-t and the photoelectric conversion element 5 for generating a start signal. 5 photoelectric conversion elements,
A start signal is generated when light from the light source 1 is received.

The amount of light received by the photoelectric conversion elements 15, 13, and 12 is as follows.

Due to differences in the stiffness of each surface of the rotating mirror 4, variations in transmission loss of the optical fiber bundle 7, etc., the amount of received light varies depending on the position of the projected light spot, as shown in FIG. Therefore, due to this change ν11 in the amount of received light, there is a possibility of erroneous detection.

Therefore, in order to eliminate any unevenness in the amount of reflected light depending on the location where it is detected, before inspecting the detected object 6, a correction plate is used to store a proportional coefficient for each sampling point so that the amount of light varies by a constant amount depending on the location. When inspecting the object to be inspected 6, the color can be determined by comparing the values obtained by multiplying the light receiving value by the proportional coefficient for each measurement point. However, this requires high-speed and complex arithmetic circuits such as a division circuit to calculate the proportional coefficient and a computer circuit to multiply the proportional coefficient, as well as a large capacity memory, making it expensive.

the purpose The object of the present invention is to solve all the above-mentioned technical problems.

It is an object of the present invention to provide a color defect inspection device which can be realized at a low cost and has a simple configuration for correcting unevenness in light amount depending on a detection location.

Embodiment FIG. 3 is a block diagram of an embodiment of the present invention. The light emitted from the light source 31 is sent to a group of optical shutters 3 that adjusts the amount of light.
2, the light is focused into a thin parallel beam by a lens system 33, and is irradiated onto a one-rotation mirror 371. The light is scanned by the rotating mirror 37.

The object to be inspected 441 is irradiated vertically by the radiation surface @36. The light diffusely reflected by the object to be inspected 44 is
The light is received by the optical fiber 43 placed at position 5, and the integrating sphere 42
lead to. Integrating sphere 421 mossy red.

Green and blue filters 4]a, 4na, and 39a are attached, and the respective filters 4]a, 40a, :'19
The light that has passed through a is converted into an electrical signal by the photoelectric conversion elements 4 and 40.39.

In the determination processing circuit 45, the photoelectric conversion elements 41, 40°39
The color defects in the object to be inspected 44 are detected by comparing each output signal with a preset reference signal.

The operation will be explained in detail below. Light from a light source 31 that receives xenon light, halogen light, etc. is transmitted to a group of optical shutters 32.
After passing through the lens system 33f, the light is condensed and becomes a parallel beam. The optical shutter group 321 is broken, for example, as shown in FIG. 4, the electronic shutter 32a? They are arranged in a matrix, and the amount of light is changed by electrically controlling the shielding area. Electronic shutter 32a,
As shown in FIG. 5, the shutter frame 52 and the electronic shutter section 5
1. The electronic shutter section 51.

For example, as shown in FIG.
dLanthanum Zirconate Tita
When voltage is applied to nate) 82, polarizing plate 8], 83
The polarization angle of the light changes to 90 degrees, and the structure allows light and sound to pass through. Also, make sure that no voltage is applied to BLZT82.

The polarization angles of the polarizing plates 81 and 83 remain at the predetermined angles and do not allow light sound to pass through.

Returning to FIG. 3, the light passing through the lens system 33 is as follows.

By passing through the rotating mirror 37 and the parabolic mirror 36, the object to be inspected 44 is vertically scanned at a constant speed. Photoelectric element 3 (5a) for generating a start signal.

A start signal indicating the start of the scan is generated, and the start signal is applied to the address signal generation circuit 35.

The address signal generation circuit 35 supplies an address signal to the full shutter control circuit 34 corresponding to the position of the object to be inspected 44 indicating the start of the scan. In other words, the determination processing circuit 45 generates a start signal indicating the start of scanning and a ? The position of the projected beam can be determined based on the reference clock signal.

In order to eliminate variations in light intensity caused by differences in the position of the light emitting spot, first place a standard plate, such as a white diffuser plate, over the inspection area iζ
put. Here, for example, what is the output voltage of the red photoelectric conversion element 4? Measurements are made in advance so that fluctuations in the amount of light appear as voltage fluctuations. Therefore, the addresses of the shutters to be opened and closed according to the voltage values are checked in advance to eliminate fluctuations in the amount of light.

Memory M stores the opening/closing information in correspondence with the light emitting spot position.
Store it in . The number of shutters increases or decreases depending on the degree to which the light quantity and quality # is pressed.The operation of such memory M will be explained with reference to Fig. s8. The analog/digital conversion circuit 71V′i in the determination processing circuit 45, the red R signal from the photoelectric conversion element 41, and the address signal generation circuit 3
It receives all the address signals from 5, converts them into digital signals, and compares them in a comparison circuit 72. In the memory MIC,
The vertical direction shows the address game corresponding to the light emitting spot position.
The horizontal direction indicates the number of bits corresponding to the number of the electronic shutter. When the object to be inspected 44 is moved, the contents of the memory M corresponding to the position of the light projection spot are retrieved, and the optical shunter group 32 is driven according to the contents. For example, if the position of the projected light spot corresponds to address 31 in memory M.

The contents of the address are retrieved and each electronic shutter section of the optical shunter group 32 is driven according to the contents.

Therefore, since the unevenness in the amount of light caused by the projected light spot position 8 is eliminated, reliable color defect inspection can be performed by comparing the 5 reference color signals and the inspection color signal. The shutter control circuit 34 receives each output signal of the photoelectric conversion elements 41, 40.39, and causes the electronic shutter section I11 of the optical shutter group 32 designated by the address signal from the address signal generation circuit 35.

FIG. 7 shows another embodiment of the optical shutter group 32. Light from the light source 6 is applied to the electronic chantereaus 1 to 6n, respectively. The light passing through the electronic shutters 61 to 6n is collected by the optical fiber 60 and the lens system 6A? r - pass. By providing this optical fiber 60, it is possible to increase the concentration of light.

Effects As described above, the second aspect of the present invention eliminates the need for a complicated arithmetic processing circuit that performs multiplication, division, etc. to eliminate unevenness in the amount of light, and can realize a low cost.

Also, according to the present invention, color defects in the inspected object can be detected. Can be detected accurately.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a conventional color defect inspection device, and Figure 2 is a diagram of a conventional color defect inspection device.
3 is a block diagram of an embodiment of the present invention, and FIG. 4 is an enlarged view of the vicinity of the optical shutter group 32 in FIG. 3. FIG. 5 is a diagram for explaining the configuration of the shutters in the optical shutter group 32, and FIG. 6 is a diagram for explaining the structure of the shutters in the optical shutter group 32.
2a principle? 7 is a diagram for explaining the structure of another embodiment near the optical shutter group 32, and FIG. 8 is a diagram showing the memory M? included in the determination processing circuit 45. FIG. 2 is a block diagram for explanation. 31...Light source, 32...Light shutter group, 33,6A
... Lens system, 34... Shutter control circuit, 35.
... Address signal generation circuit, 36 ... Parabolic mirror, 36
a...Start signal generating element, 39a...Blue filter. 40a...Green filter, 41a...Red filter. 39.40,4]...Photoelectric conversion element, 43.60...
・Optical filter, 44...Object to be inspected, 45...Judgment processing circuit, M...Memory agent Patent attorney Kei Nishi Part-IIA-Ogi (Ro) Procedural Amendments September 1980 25th Japanese Patent Application No. 59-107094 2. Name of the invention Color defect inspection device 3. Relationship with the case of the person making the amendment Applicant address name (5B3) Matsushita Electric Works Co., Ltd. Representative 4, Agent address Nishi-ku, Nishi-ku, Osaka City Honmachi 1-13-38 Shinko Sangbu Building Country Equipment EX 0525-5985 INTAPT
J International FAX GIrI&GIl (06)538-0
247 Telephone (06) 53 B-0263 (Representative) 6, Detailed explanation of the invention column 7 of the specification subject to amendment, Contents of amendment (1) Specification ti, page 3 PIS lines 9 to 10 The text "Come on, 1st revision circuit" is corrected to "Ice body circuit". (2) On page 5, line 14 of the specification, [BLZ, TJ is corrected to "Pi, ZTJ." Above 2-

Claims (1)

[Scope of Claims] A light shutter means for fully adjusting the amount of light from a light source, and a light shutter means for fully condensing the light passing through the light shutter means. A color defect for detecting a color defect of the object to be inspected, which includes a lens system that irradiates the object to be inspected, and a conversion means that collects reflected light from the irradiated light and converts the reflected light into a light intensity signal. A color defect inspection device characterized in that the inspection device is provided with a memory for storing information for controlling the light shutter means so as to suppress variations in the amount of reflected light depending on the irradiation location of the object to be inspected with the irradiation light.