JP2747690B2 - Color identification device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention irradiates a color discriminating device, particularly an object, with light,
The present invention relates to a device that performs signal processing on the reflected or transmitted light to identify a color. [Prior Art] Conventionally, this type of color discriminating apparatus uses white light of a halogen lamp continuously emitted by a DC power supply as detection light, while a photoelectric conversion element in which a color filter is disposed on a light receiving surface on a light receiving side. , One set for each of the three primary colors of red, blue, and green. After the white detection light reflected by the object whose color is to be identified is directly separated into three primary color signals by the photoelectric conversion element, In general, the signal processing is performed in parallel every time. [Problems to be Solved by the Invention] However, since white light of a halogen lamp is used as detection light, continuous emission of the lamp is required, and as a result, the influence of disturbance light is inevitable. There are many inconveniences, such as large heat generation itself and limited size reduction. The present invention has been made in view of such inconveniences, and generates less heat from the light projecting unit, can reduce the size of the entire apparatus, can reduce the influence of disturbance light as much as possible, and can select the use environment. It is an object of the present invention to provide an apparatus capable of performing highly accurate color identification. [Means for Solving the Problems] FIG. 1 is a block diagram schematically showing a color discriminating apparatus according to the present invention, in which an object 1 whose color is to be discriminated has three primary colors of red, blue and green. A light projecting means for sequentially irradiating the light 2a, 2b, 2c as detection light, a light receiving means for receiving the reflected or projected light 2d of the object 1 and converting it into a series of electric signals, and detecting from the converted electric signal The detection unit extracts only the detection information corresponding to the light 2d, and the unit for identifying the color of the detection target 1 based on the value of the detection information. The light projecting means includes light-emitting elements 3a, 3b, and 3c, one set corresponding to each of the three primary colors of light, red, blue, and green. Lighting in a pulsed manner while providing an interval enables detection light for three primary colors
2a, 2b, and 2c are intermittently applied to the same portion of the detection target 1. The detection means includes a filter means for selectively extracting a signal having the same frequency as the pulse rate of the drive signal from the input electric signal, and a signal extracted from the filter means is synchronously detected with the drive signal to separate a color signal. A synchronous detection circuit, an integration circuit for integrating a color signal extracted from the synchronous detection circuit to form a series of detection information, and a substantially center voltage value in the detection information for each color extracted from the integration circuit. An A / D converter for converting to a digital value. Further, the light emitting elements of each color in the light emitting means are lit at a time for a plurality of pulses in the drive signal as shown in FIGS. 2 and 3, and the filter means is set to the pulse rate of the drive signal. It comprises a bandpass filter 22 having a center frequency. Further, as shown in FIGS. 4 and 5, a multiplexer for sequentially combining the detection information for each color extracted from the above-described integration circuit in a time series, and a multiplexer for the detection information for each color extracted from the multiplexer. An A / D converter for converting a substantially central voltage value into a digital value may be provided. In this case, the light emitting element of each color in the above-mentioned light projecting means changes the element which is turned on for each pulse in the drive signal, and the filter means has a tuning having a center frequency in the pulse rate of the drive signal. It is composed of an amplifier circuit 40. [Operation] In the above configuration, the detection target 1 is located at the focal position of the light projecting means.
When the apparatus is operated in a state where the identification surface 4 is arranged, a driving voltage of a constant pulse rate is applied to each of the red, green and blue light emitting elements 3a, 3b, 3c with a time lag, and the same voltage is applied to the same portion of the detection target 1. The red, blue, and green detection lights 2a, 2b, and 2c are emitted at predetermined time intervals. After the detection light is reflected or transmitted by the detection target 1, the detection light is sequentially incident on the light receiving means and converted into a series of electric signals. By the way, when the detection light is reflected or transmitted by the detection target 1, a color complementary to the color to be identified is absorbed, and as a result, component information of three primary colors that can specify the color of the detection target 1 is obtained. Although the detection light 2d including the detection light 2d is obtained, it is inevitable that disturbance light from an external fluorescent lamp or the like is simultaneously incident on the light receiving means in addition to the detection light 2d, and is superimposed as noise on the electric signal. I have. Therefore, in the next detecting means, the lighting timing information of the light emitting element group 3 is obtained from the light projecting means, and based on this information, only the detection information corresponding to the incident intensity of the detecting light 2 is selectively extracted to obtain the electric power. Detection information is extracted while removing noise corresponding to disturbance light from the signal.
That is, after removing noise having a frequency different from that of the detection light by the filter means, the synchronous detection circuit removes noise having substantially the same frequency as that of the detection light but having a different phase. It is alleviated by the circuit. The noise-cut detection information is further combined with color information for specifying the emission color of the light-emitting elements 3a, 3b, 3c during lighting by the identification means, and component information for each of red, blue, and green is sequentially obtained. The color of the detected object 1 is identified using the component information of the three primary colors. [Embodiment] As shown in FIG.
A small product, such as a dry battery, which is continuously carried in the above process is defined as the detection target 1, and the apparatus is configured to detect the exterior color of the product, automatically determine whether the color is appropriate or not, and control the product selection. An example is shown, but the present invention is not limited to this, and it goes without saying that the present invention can be carried out in almost the same manner in various devices, such as a measuring device that simply displays the name of the identified color on a display, or a device that inspects various color products online. . As shown in FIG. 2, the color discriminating apparatus according to the present invention applies red, blue, and green detection lights 2a, 2b, and 2c to an object 1 whose exterior color is to be identified.
A light projecting unit 6 for individually irradiating the detection light 2d, a light receiving unit 7 for condensing the detection light 2d reflected on the detection target 1 and converting the same into a predetermined electric signal, and receiving the detection light 2d from the converted electric signal. A detection unit 9 for extracting component information of a voltage value proportional to the reflection intensity of the detection object 1, a component ratio for each color is obtained from the color information specifying the color of the detection light 2 and the component information, and the component ratio is determined based on the component ratio. after performing the identification of colors in the a processing unit 10 for outputting a predetermined control signal S ₁₀ corresponding to the identification result, the control signal S ₁₀
And a control unit 11 that performs a control operation according to. The light projecting section 6 is supplied from the oscillation circuit 12 by several kilohertz as shown in FIG.
A pulse signal S ₁ having a pulse rate of about z to several tens of kHz is continuously oscillated, and can be sequentially applied to the light emitting element group 3 via the drive signal generation circuit 13. Drive signal generation circuit
13 is the pulse signal S _{1 connected} to the application of the gate signal.
The gate signal generation circuit 14 generates three-phase gate signals S ₂ , S ₃ , and S ₄ from the pulse signal S ₁ and inputs the signals to each gate, so that a predetermined number of pulses continue. Later, the output gates are sequentially switched, and FIG. 3 (b)
Three sets of drive signals S ₅ , S ₆ and S ₇ as shown in (c) and (d) are formed. This drive signal is further power-amplified by the amplifier circuit 15 and then applied individually to the light emitting elements 3a, 3b, 3c. The light-emitting element group 3 is composed of three sets of light-emitting diodes 3a, 3b, and 3c, each of which emits one of the three primary colors of light, red, blue, and green. Are different, each light emitting diode is
By properly adjusting the amplification within the range of the allowable power consumption of 3a, 3b, and 3c, or by connecting a plurality of light-emitting diodes of the same color in parallel to emit light at the same time, the light-emitting intensity of each set of light-emitting elements is mutually different. They are set to be substantially equal and as large as possible. Thus, the detection light 2a, 2b, 2c generated from each of the light emitting diodes 3a, 3b, 3c can be irradiated to one point of the detection target 1 using the optical system 16 including the condenser lens. The detection light 2d reflected by the object 1 is made to effectively enter the light receiving unit 7. The light receiving unit 7 guides the detection light 2d to the light receiving surface of the photoelectric conversion element 20 such as a photodiode by the optical system 17. Photoelectric conversion element
Reference numeral 20 denotes a device having sufficient sensitivity to each of the red, blue, and green spectra emitted from the light projecting unit 6. The device 20 converts the incident light 2d into an electric signal having an amplitude value proportional to the incident intensity. Then, after being amplified by the preamplifier 21, it is input to the detection unit 9. The detection unit 9, by passing through a band-pass filter 22 first has a center frequency pulse rate of the pulse signals S ₁ a lighting frequency of the light emitting element group 3, after removing the effects of unwanted ambient light, OP amp 23 A series of sinusoidal color signals S related only to the detection light 2d reflected by the surface 4 of the detection target 1 as shown in FIG.
Since ₈ is obtained, further lock-in amplifier the signal S ₈
Input to 24 for signal processing. The lock-in amplifier 24 includes a synchronous detection circuit 25 and an integration circuit 26.
The input color signal S ₈ is converted into a step-like voltage S ₉ as shown in FIG. 3 (f), which is proportional to the amplitude value of the signal S ₈ .
Convert to The synchronous detection circuit 25 has a transistor switch 27 disposed between the input side of the integration circuit 26 and the ground. The on / off timing of the switch 27 is controlled by the oscillation circuit 12 of the light emitting unit 6 to emit light. The detection light 2a, 2b,
During the period in which 2c is not emitted, the input side of the integrating circuit 26 is grounded to cut off the input, and the signal S ₈ is input to the integrating circuit 26 in correspondence with the lighting timing of the light emitting element group 3, whereby the signal S ₈ Only the same frequency component value as the emission frequency is sent to the integrating circuit 26 in a pulse form. Here, as the synchronous detection circuit, a field effect transistor analog multiplier, a balanced demodulator and the like can be used in addition to the transistor. An input signal in the integrating circuit 26 integrates and converts amplified signal S ₉ of the voltage value proportional to the peak value of the signal. Such a voltage value is proportional to the reflection intensity of each of the red, blue, and green detection lights on the detection target, and furthermore, the detection lights 2a, 2
Since b and 2c are sequentially switched after a predetermined period of time, the vicinity of the central value is stabilized to be substantially constant, and the values V ₁ and V ₂ are stepwisely changed.
Signal S ₉ to V _2, V ₃ changes is obtained. Further, the signal S ₉ is sampled by the A / D converter 30 at the central portion of each color where the voltage value is relatively stable, digitally encoded, and then input to the arithmetic processing unit 10 as component information. The arithmetic processing unit 10 has a central processing unit (CPU) as the center of control, enables manual operations such as data input from the operation unit 31, and executes the following operation procedure by a program stored in the ROM in advance. A microcomputer which is automatically controlled and separates component information from each other for each of the three primary colors by using color information for specifying the light-emitting elements 3a, 3b, and 3c and the component information. seeking component ratio of each color from the minute component information, further compared to similar component ratio which has been stored for advance reference color the ingredients ratio, and outputs a control signal S ₁₀ corresponding to the determination result. The color information is extracted from, for example, the gate signal generating circuit 14 of the light projecting unit 6 and enables to specify the color and the lighting period of the currently emitting light emitting elements 3a, 3b, 3c. It is determined what color component information the input digital code is. Here, as initial data,
By storing the component information when the detection light 2a, 2b, 2c of each color is directly input, the reflection is performed based on the ratio between the initial value and the component information when the object 1 is actually reflected. Since the ratio is calculated for the detection lights 2a, 2b, and 2c for the three primary colors, the chromaticity of the surface 4 of the detection target 1 is specified by calculating the component ratio of the reflectance, and the value of the reflectance itself is determined. Alternatively, the brightness is specified from the value of the square of the sum of the squares of the respective reflectances. Therefore, the above-described measurement is performed in advance for one or a plurality of reference colors to be used as a reference, and the chromaticity and lightness serving as the reference are stored, and the reference value is compared with the actual inspection value of the detection target 1. when the both are in coincidence or in the predetermined range is determined, a predetermined control signal S ₁₀ the control unit
It is set to output to 11. The control unit 11 based on the control signal S ₁₀ to be inputted, but the exterior color of the detection object 1 in the case of passing the conveyor 5 migrated one stage to check as well the following products, it is determined that failure Then, the product 1 is discharged from the line, and the sorting process based on the exterior color of the product is automatically and continuously performed. Figure 4 is a another embodiment of the present invention, in the present embodiment, FIG. 5 from the pulse signals S ₁ of FIG. 5 by the drive signal generating circuit 13 (a) (b) ( c) 120d each other as in (d)
By forming three-phase drive signals S ₁₁ , S ₁₂ , and S ₁₃ whose phases are shifted by degrees, and applying the signals to the light-emitting element group 3, the light-emitting elements 3a, 3b, and 3c that are turned on for each pulse are generated. In addition to the change, the lighting cycle is repeated a plurality of times. On the other hand, at the detection section 9, by selecting amplifying the input signal with the tuning amplifier circuit 40 to the frequency of the pulse rate near the pulse signals S ₁ and the amplification band, the signal such as FIG. 5 (e) S After the signal ₁₄ is obtained, the signal S ₁₄ is converted into signals S ₁₅ , S ₁₆ , and S ₁₇ for each detection light of each color of red, blue, and green by the synchronous detection circuit 41 as shown in FIGS. 5 (f), (g), and (h). Are separated. Synchronous detection circuit 41
Consists of three sets of gates, each of which has a driving signal S ₁₁ , S
_A gate signal having the same phase as S ₁₂ and S ₁₃ and having the same rise but a slow fall is applied, and further, an integration circuit 42 is connected to the output side to integrate the separated signals S ₁₅ , S ₁₆ and S ₁₇ in parallel for each color. As a result, a DC voltage is formed. Such voltages are taken out in time series by the multiplexer 43, converted into signals similar to those shown in FIG. 3 (f), and then subjected to signal processing in substantially the same manner as in the above embodiment. In the above embodiment, a part of the configuration is implemented by a program, but it may be configured by a specific circuit. The light-emitting element 3 can use various light sources such as a laser beam. In addition to spot-color discrimination, it is also possible to scan and discriminate a pattern in a plane. [Effects of the Invention] As described above, the present invention provides three sets of light emitting elements that emit three primary colors.
Since the detection light 2 is generated by lighting the pulses 3a, 3b, and 3c in a pulse shape, the detection light that is stronger than the required power consumption is obtained, and the light emitting element 3 itself generates heat as much as possible. , And the size of the entire apparatus can be reduced. Furthermore, since the detection information corresponding to the detection light 2d reflected or transmitted by the detection target 1 is extracted and signal-processed in connection with the emission timing information of the light-emitting element 3, noise due to disturbance light is reduced. This has many advantages such as high-precision color identification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an outline of the present invention. FIG. 2 is a block diagram showing an embodiment of the present invention, and FIGS. 3 (a) to 3 (f) are waveform diagrams for explaining the operation of FIG. FIG. 4 is a block diagram showing another embodiment, and FIGS.
(H) is a waveform diagram illustrating the operation of FIG. 1 ... detected object, 2 ... detection light, 3 ... light emitting element, 6 ...
... Floodlight section, 7... Light receiving section, 9... Detecting section, 10.

Claims (1)

(57) [Claims] 1.3 The light emitting elements of the three primary colors are individually provided, and the light emitting elements of each color are illuminated in a pulsed manner with a predetermined time interval between the lighting times, so that the colors to be identified can be identified. A light projecting means for intermittently irradiating the detection light of three primary colors to the same place of the detection object, and the light reflected or transmitted by the detection object is incident and converted into an electric signal of an amplitude value corresponding to the incident intensity Detecting means for extracting only detection information corresponding to detection light from the electric signal in association with the lighting timing of the light emitting element; and three primary colors based on the detection information and color information for specifying the light emitting element being lit. And a means for determining each component information and identifying the color of the detected object, wherein the light emitting element of the light emitting means is illuminated in a pulse shape by a drive signal at a constant pulse rate. And the detecting means includes: Filter means for selectively extracting a signal having the same frequency as the pulse rate of the drive signal from the input electric signal; synchronous detection circuit for synchronously detecting the signal extracted from the filter means with the drive signal and separating a color signal; An integration circuit for integrating a color signal extracted from the synchronous detection circuit to form a series of detection information; and converting a substantially central voltage value in the detection information for each color extracted from the integration circuit into a digital value. And an A / D converter, wherein the light emitting elements of each color in the light emitting means are lit at a time for each of a plurality of pulses in the drive signal, and the filter means focuses on the pulse rate of the drive signal. A color discriminating device characterized by being a bandpass filter (22) having a frequency. 2.3 Light-emitting elements of three primary colors are individually provided, and the light-emitting elements of each color are illuminated in a pulsed manner while providing a predetermined time interval between the light-emitting elements, so that the three primary colors can be identified at the same location of the object to be identified. Light-emitting means for intermittently irradiating the detection light with light, light-receiving means for receiving light reflected or transmitted by the object to be detected and converting the light into an electric signal having an amplitude value corresponding to the incident intensity, and lighting of the light-emitting element Detecting means for extracting only the detection information corresponding to the detection light from the electric signal in conjunction with the timing; obtaining the component information of each of the three primary colors from the detection information and the color information specifying the light emitting element being lit; Means for identifying the color of an object, wherein the light emitting element of the light emitting means is illuminated in a pulse shape by a drive signal of a constant pulse rate, the detecting means, Input electric signal Filter means for selectively extracting a signal having the same frequency as the pulse rate of the drive signal; synchronous detection circuit for synchronously detecting the signal extracted from the filter means with the drive signal and separating color signals in parallel; An integrating circuit that integrates the color signal extracted from the detection circuit for each color to form detection information output in parallel, and sequentially synthesizes detection information for each color extracted from the integration circuit in time series And a A / D converter for converting a substantially central voltage value in the detection information for each color extracted from the multiplexer into a digital value. In this case, the element to be lit for each pulse is changed, and the filter means includes a tuning amplifier circuit (40) having a center frequency at the pulse rate of the drive signal. ).