JPH0552725U - Colorimeter - Google Patents

Abstract

(57) [Abstract] [Purpose] Chromatic chromaticity with a minimum number of light receiving elements so that the reflectance or transmittance for each color of an object to be detected can always be measured accurately with a relatively simple structure. Provide a total. A light source unit 12 that illuminates an object 11 to be detected with illumination light, a light receiving unit 13 that receives reflected light or transmitted light from the object to be detected, and red and green of the object based on the light reception signals. , A calculation unit 15 for calculating the ratio of the reflectance or the transmittance to the three colors of blue, the light source unit includes light emitting diodes for respectively emitting the three colors, and the light receiving unit extends over the three colors. It is equipped with only one light-receiving element with light-receiving sensitivity, and by sequentially driving the light-emitting diodes of each emission color to light up, reflection of the detected object is performed based on the light-receiving signal of the corresponding light-receiving element when each light-emitting diode emits light. The colorimeter 10 is configured to calculate the rate or transmittance.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a colorimeter for color measurement of an object.

[0002]

[Prior Art]

 Conventionally, such a colorimeter is constructed as shown in FIG. 2, for example. In the figure, a colorimeter 1 includes a light source section 3 for irradiating an object 2 to be detected with illumination light, and a reflection of light emitted from the light source section 3 on the surface of the object 2 and reflected on the surface of the object 2. A light receiving part 4 for receiving light, a light receiving part 5 for monitoring which is arranged adjacent to the light source part 3 and directly receives illumination light from the light source part 3, and the light receiving part for measurement. 4 and the monitor light-receiving unit 5 based on the light-receiving signals amplified by the amplifiers 6 and 7, respectively, and a calculation unit 8 which calculates the ratio of the reflectance or the transmittance of the detected object 2.

As the light source unit 3, a light source that emits white light, such as a xenon lamp or a halogen lamp, is usually used. Further, the measurement light-receiving unit 4 uses a red, green, and blue filter so that the reflectance or transmittance of the detected object with respect to the three colors of red, green, and blue can be measured. The monitor light-receiving unit 5 is similarly provided with three or three-divided light-receiving elements having the light-receiving sensitivity for the three colors, and similarly, the monitor light-receiving unit 5 has three light-receiving sensitivities for the three colors. It is equipped with a light receiving element.

According to the colorimeter 1 configured as above, the light source unit 3 emits white light by supplying power to the light source unit 3, and the white light irradiates the object 2 to be detected. To be done. The light reflected on the surface of the object 2 to be detected is detected by the light-receiving element corresponding to each color of the light-receiving unit 4, and a signal from each light-receiving element corresponding to the reflected light by the object 2 to be detected for the three colors. Is input to the calculation unit 8 via the amplifier 6. On the other hand, the light from the light source unit 3 is directly incident on each light receiving element of the monitor light receiving unit 5, and a signal corresponding to the luminous intensity of the light from the light source unit 3 for each of the three colors is similarly emitted from each light receiving element. It is input to the calculation unit 8 via the amplifier 7.

As a result, even if the white light from the light source unit 3 is unstable, the calculation unit 8 can generate the three colors of the white light from the light source unit 3 based on the signal from the monitor light receiving unit 5. The reflectance for the three colors from the light receiving section 4 for measurement is corrected by the luminosity for the three colors by detecting the luminosity for the three, and the reflectance of the detected object 2 for the three colors is always accurate. Calculate to. Thus, the arithmetic unit 8 outputs a signal relating to the reflectance ratio of the object 2 to be detected from the output terminal 9.

[0006]

[Problems to be solved by the device]

 However, in the colorimeter 1 configured as described above, since a light source such as a xenon lamp or a halogen lamp is used as the illumination light, the light from the light source 3 is unstable in terms of color. In addition, a monitor light-receiving unit 5 is required, and a light-receiving element for measurement is used for each color in order to receive the reflected light for each color, and the white light from the light source unit 3 has a luminous intensity for each color. Since a light-receiving element for monitoring is used for each color to detect, a large number of light-receiving elements and color filters are required. As a result, the number of parts is large and the configuration is complicated, resulting in relatively high component costs and assembly costs.

In view of the above points, the present invention provides a minimum number of light receiving elements so that the reflectance or the transmittance of each color of the object to be detected can be always accurately measured with a relatively simple structure. The purpose of the present invention is to provide a chromaticity colorimeter.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the colorimeter according to the present invention comprises a light source unit that illuminates an object to be detected with illumination light, a light receiving unit that receives reflected light or transmitted light from the object, and The light source unit is configured to calculate the ratio of the reflectance or the transmittance of the detected object to the three colors of red, green and blue based on the received light signal from the light receiving unit. In addition to being equipped with light-emitting diodes that emit light of each of the three colors, the light-receiving section is equipped with only one light-receiving element that has photosensitivity over the three colors described above. By doing so, the reflectance or the transmittance of the object to be detected is calculated based on the light receiving signal of the light receiving element corresponding to the light emission of each light emitting diode.

[0009]

[Action]

 According to the above configuration, the light emitting diodes of the respective light emitting colors of the light source unit are sequentially driven to be driven, whereby the reflectance of the detected object or the transmission of the detected object is determined based on the light receiving signal of the light receiving element when each light emitting diode emits light. Since the ratio is calculated, since the illumination light that illuminates the object to be detected is the light emitted from the light emitting diode, the emission color is relatively stable, and the reflection of the object to be detected with respect to the emission color. The rate or transmittance can be calculated accurately.

Therefore, since it is not necessary to correct the color of the light from the light source unit, the light receiving unit for the monitor is unnecessary, and the illumination light from the light source unit is emitted from the light emitting diode of each emission color. Therefore, as the light receiving element, it is possible to receive the light from the light emitting diode by preparing only one light receiving element having the light receiving sensitivity that includes the emission color of these light emitting diodes. With a very simple structure, the reflectance or transmittance of the detected object for each color can always be measured accurately.

[0011]

【Example】

 FIG. 1 shows an embodiment of a colorimeter according to the present invention. In FIG. 1, a colorimeter 10 includes a light source section 12 that illuminates an object 11 to be detected with illumination light, and the light source section 12 irradiates the surface of the object 11 and reflects the surface of the object 11. A light receiving section 13 for receiving the reflected light, and a calculating section 15 for calculating the ratio of the reflectance or the transmittance of the detected object 11 based on the light receiving signal amplified by the amplifier 14 from the light receiving section 13. An external output terminal 15a for outputting a signal of a calculation result from the calculation unit 15 to the outside.

As shown in the figure, the light source unit 12 is composed of three light emitting diodes 12r, 12g, 12b which respectively emit three colors of red, green and blue, and each light emitting diode 12r, 12g, 12b is The pulse signals from the oscillating circuit 16 make it possible to sequentially emit light so as to appropriately emit light of three colors. The light receiving section 13 is composed of only one light receiving element having a light receiving sensitivity for the above three colors.

Further, sample hold circuits 17r, 17g, 17b for the above three colors are provided between the amplifier 14 and the arithmetic unit 15, and the sample hold circuits 17r, 17g, 17b are provided. A light-receiving signal from the amplifier 14 is input to each of the input terminals, and a pulse signal from the oscillation circuit 16 for setting timing for each color is input to each input terminal.

The colorimeter 10 according to the present invention is configured as described above, and the oscillation circuit 16 sequentially causes the red, green, and blue light emitting diodes 12r, 12g, and 12b of the light source unit 12 to emit light in sequence. Then, the red light, the green light, or the blue light emitted from each of the light emitting diodes 12r, 12g, 12b is irradiated to the detected object 11, is reflected by the surface of the detected object 11, and then is received by the light receiving unit 13. Incident on the element.

The light receiving signal output from the light receiving element is amplified by the amplifier 14, and then input to each sample hold circuit 17r, 17g, 17b, and based on the pulse signal from the oscillation circuit 16, each light emitting diode 12r, 12g, Corresponding to the light emission of 12b, the sample-and-hold circuits 17r, 17g, and 17b hold the received light signal, and the received light signal is input to the calculation unit 15 as the received light signal for each color. As a result, the arithmetic unit 15 calculates the ratio of the reflectance of each color from the luminous intensity of the reflected light from the detected object 11 for each color, and outputs it from the external output terminal 15a.

[0016]

As described above, according to the present invention, by sequentially driving the light emitting diodes of each emission color of the light source unit, the light receiving signals of the light receiving elements at the time of light emission of the respective light emitting diodes are output. Since the reflectance or transmittance of the object to be detected is calculated based on this, since the illumination light that illuminates the object to be detected is the light emitted from the light emitting diode, the emission color is relatively stable. The reflectance or transmittance of the object to be detected with respect to the emission color can be accurately calculated. Therefore, since it is not necessary to correct the color of the light from the light source unit, the monitor light receiving unit which has been conventionally required becomes unnecessary, and the illumination light from the light source unit can be emitted from the light emitting diodes of each emission color. It is possible to receive light from the light emitting diode by preparing only one light receiving element having a light receiving sensitivity that includes the light emission color of these light emitting diodes. Thus, according to the present invention, by providing a minimum number of light receiving elements, it is possible to obtain an extremely excellent color color with a relatively simple structure, which can always accurately measure the reflectance or transmittance for each color of the detected object. A meter is provided.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a colorimeter according to the present invention.

FIG. 2 is a schematic diagram showing an example of a conventional colorimeter.

[Explanation of symbols]

 10 Color Chromometer 11 Detected Object 12 Light Source 12r Red Light Emitting Diode 12g Green Light Emitting Diode 12b Blue Light Emitting Diode 13 Light Receiving Section 14 Amplifier 15 Calculation Section 15a External Output Terminal 16 Oscillation Circuit 17r Sample Hold Circuit 17g Sample Hold Circuit 17b Sample Hold circuit

Claims (1)

[Scope of utility model registration request] 1. A light source unit for irradiating an object to be detected with illumination light, a light receiving unit for receiving reflected light or transmitted light from the object, and a light receiving signal from the light receiving unit. In a colorimeter comprising a calculation unit for calculating the ratio of reflectance or transmittance for the three colors red, green and blue of the detected object, the light source unit emits each of the three colors red, green and blue. In addition to the light emitting diode, the light receiving section is provided with only one light receiving element having a light receiving sensitivity for the above three colors, and by sequentially driving the light emitting diodes of each emission color to be turned on, A colorimeter, wherein the reflectance or the transmittance of an object to be detected is calculated based on a light receiving signal of a light receiving element corresponding to the time of light emission.