JPS62142240A - Photoelectric colorimeter which can measure density - Google Patents

Abstract

PURPOSE:To measure a chromatic value and density value with one unit of photoelectric colorimeter by providing a means for calculating the density from the information expressing the quantity of light of the basic color components of the light from a standard density sample stored in a memory means and the information expressing the quantity of light of the basic color components of the light from a sample to be measured. CONSTITUTION:This photoelectric colorimeter has a photoelectric conversion part 100 and a data processing part 200. The data processing part 200 is provided with a CPU5 which makes control and arithmetic processing, a ROM6 in which a program for system control, color conversion, etc. is stored, a RAM7 which is the memory means to store color information, density information, etc., a clock 8, an I/O port 9, etc. The information expressing the quantity of light of the basic color components of the light from the standard density sample irradiated by a light source is stored into the RAM7 via the photoelectric conversion part 100. The means for calculating the density calculates the information expressing the quantity of light of the basic color components of the light from the standard density sample stored in the RAM7 and the information expressing the quantity of light of the basic color components of the light from the sample to be measured.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention relates to a photoelectric colorimeter capable of measuring concentration. , the reflected or transmitted light from the illuminated sample to be measured is divided into tristimulus values (x, y, z) or three primary colors (R,
The data processing unit converts the obtained tristimulus values (X, Y, Z) or the three primary colors (R, G, B) into chromaticity. There is something that allows you to get .

<Problems to be Solved by the Invention> However, Kitaki's conventional photoelectric colorimeter has a problem in that although it can measure color values, it cannot measure density. For example, in the printing and photography industries, liquids are often controlled by concentration, and even if only the color value is known,
The problem is that only the color of the liquid itself can be determined, but it does not provide feedback to the process.

Therefore, an object of the present invention is to enable the measurement of color values and density values using a single optical 7π colorimeter.

Means for Solving the Problems> In order to solve the above problems, the photoelectric colorimeter capable of measuring concentration of the present invention has a memory that stores information representing the amount of basic color components of light from a concentration reference sample. and a density for calculating the density from information representing the light weight of the basic color component of the light from the concentration reference sample stored in the memory means and information representing the light amount of the basic color component of the light from the sample to be measured. It is characterized by comprising a calculation means.

<Operation> Information representing the amount of light of the basic color component of the light from the concentration reference sample irradiated by the light source is stored in the memory means via the photoelectric conversion section. The concentration calculating means calculates the concentration from the information representing the amount of basic color components of light from the concentration reference sample and the information representing the amount of basic color components of light from the sample to be measured, which are stored in the memory means. , the concentration value is obtained.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a diagram of this embodiment, FIG. 2 is a timing chart 1 of the photoelectric conversion section, and FIG. 3 is a flowchart showing photometry and import of tristimulus value data from the photoelectric conversion section.

As shown in FIG. 1, this photoelectric colorimeter capable of measuring density includes a photoelectric conversion section (100) and a data processing section (200). The photoelectric conversion unit (100) has six photodiodes (p+ to e) as optical sensors, three of which are photodiodes (p+ to e).
One photodiode (P, ~,) is used to measure sample (1), and the remaining three photodiodes (■) are used to measure sample (1). ) is used for measurement of light source (2), and by calculating (measured value of sample) / (measured value of light source), the fluctuation of light source (2) is canceled, making it possible to always measure with constant deafness. I have to.

As for sample (1), the light from light source (2) is separated into basic color components by optical filters (F, ~6),
The photodiode (P, ~8) detects it, and each photoelectric conversion circuit (E, ~8) converts it into an electrical signal and amplifies it, and the amount of electricity corresponding to the optical signal is sent to the gate (Gl).
~6) through each sample hold circuit (H1
~8), and is further sent sequentially to the A/D conversion circuit (3) via the gate (G?~12), and then processed by the data processing section (
The central processing unit (CPU) (5) is the control unit of the
) can be taken in as a digital value. Note that 1.1 is
This is a lighting circuit. In this way, the fluctuation of the light source (2) is canceled, and the calculation of the tristimulus value data (X, Y, Z) of the sample (1) in a constant state is performed by the third CPU (5).
Steps 81-l in the figure! , s14, step S
It will be held at I3. A(1), A in step S+3
(2),...,A(6) is a photodiode-+:'CP
,, P2. ...P,) corresponds to the output. When taking in signals from the photodiodes (P, . . . P,), the gates (01 to 1.) open at the timing shown in FIG.

On the other hand, the data processing i'm (200) includes a CPU (5) that performs control and arithmetic processing, and a read-only memory (ROMX6) that stores one program for system control, color conversion, etc. Random access memory (Y'1.1~
M) (7), clock (8), and I/l') boat (
9), a display unit (10) such as a liquid crystal display device or a printer for displaying the results obtained by measurement, and a keyboard (12) for operating the mold. Furthermore, a warning section (11) and a decoder (13) are provided.

Before using this photoelectric colorimeter, it is first necessary to perform calibration according to the flowchart shown in FIG. first,
Press the calibration key on the keyboard (12) to enter calibration mode. Prepare a calibration sample to serve as a calibration standard, and proceed to step S2.
1, use the numeric keypad to enter the tristimulus values (Xo, Y
o, Zo). Next, press the measurement key to proceed to step S22, and measure the calibration sample according to subroutine 1 shown in FIG. 4 to obtain tristimulus values (X, , Y, Z). In step S23, calibration constants (α, β, γ
) is calculated using the following formula, and the tristimulus value (Xo,
Yo, Zo) and calibration constants (α, β, γ) as IλAM
(7).

X, Y, Z When measuring the concentration of an actual sample, as shown in Figure 5,
It is necessary to measure the density reference sample and input it into the color difference reference color channel i of the RAM (7). keyboard(
12) Press the color difference input key to enter the color difference reference color input mode. In step S31, a memory channel for the color difference reference color is selected. Next, the process advances to step S32, and the fourth
The reference sample is measured for concentration according to subroutine 1 in the figure, and tristimulus values (X, Y, Z) are obtained. Next, Ste Tsubu S3
3, add calibration constants (α, β) to these tristimulus values (X, Y, Z).
.

γ) and perform correction, and the obtained result is (X　m).

Ym, Zm) and store them in RAM (7).

Next, the process proceeds to step 934 to calculate the corrected tristimulus values CXm, YIn, Zm) in the XYZ color system mustard*.
The display amount is converted to the a*b* display system, and the chromaticity point Ct, *.

a*, b*). Then, in step S35,
The tristimulus values (Xm, Ym, Zm) and chromaticity points (L, *, a*, b*) of the base yarn sample of density are stored in the RAM (7').

After completing the above preparations, the color value or density value is measured as shown in FIG. Now keyboard 1” (12)
It is assumed that the density display mode is specified using the color system switching key. First, in step S41 shown in FIG. 6, operate the measurement key to measure the sample according to subroutine 1 shown in FIG. 3, and obtain tristimulus values (X, Y, Z).

Next, the process proceeds to step S42, where the tristimulus value (X
, Y, Z) by the calibration constants (α, β, γ), and the obtained results are stored in the memory as (Xm, Ym, Zm).

Next, the process proceeds to step S43, where it is determined whether or not the mode is the density display mode, and if the mode is the density display mode, the process proceeds to step S44. In step S44, the memory channel (i) of the color difference reference color is recalled, and the tristimulus value (Xmemo(i)) after the calibration of the density reference sample is recalled.

The following concentration calculation is performed using Ymemo(i), Zmemo(i)) and the aforementioned tristimulus values (Xm, Ym, Zm) of the sample to be measured.

Xm In step S45, the concentration calculation result S45 obtained by the above-mentioned formula is displayed on the display section (lO). Note that step S44 corresponds to concentration calculation means.

On the other hand, if it is determined in step S43 that it is not the density display mode, the process proceeds to step S4e, where the color space is converted to the specified color system from the corrected tristimulus values (Xm, Ym, Zm), and the display section is displayed. Display the color value at (lO).

In Example L, the light from the sample is measured at tristimulus values (X.

It was detected by separating it into basic color components of Y, Z), but R (red)
, G (green), and B (blue), which may be separated into basic color components for detection. Further, in the photoelectric conversion section, a sensor having spectral sensitivity for color value measurement and a sensor having spectral sensitivity for displaying density may be used so that both can be easily selected.

<Effects of the Invention> As is clear from the above, according to the present invention, since a memory means and a density calculation means are provided, color values and density values can be measured at the same time with one photoelectric colorimeter. . In particular, when measuring a liquid, not only the color value and color difference value but also the optical density and density difference are measured. Feedback on correction work can be easily provided.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a photoelectric color meter capable of measuring concentration according to an embodiment of the present invention, Fig. 2 is a timing diagram of the photoelectric conversion unit, and Fig. 3 is data of three stimuli 1'llX of a sample. 4 is a flowchart showing the calculation of calibration constants and storage of the chromaticity point of the calibration sample. FIG. 5 is a flowchart showing the measurement of tristimulus values of the concentration sample and color space conversion. FIG. 6 is a flowchart showing the measurement of density and color values of a sample. ! ...Sample, F,,F7. ..., Fa... optical filter, P 1. Pt,...,P6
...Photodiode, 5...CPU,
6...ROM% 100...Photoelectric conversion section, 2
00...Data processing section. Patent applicant: Minolta Camera Co., Ltd. Representative: Patent attorney: Aoyama Aoyama, second person, AID receptionist

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Claims (1)

[Claims] (1) The photoelectric conversion unit separates the light from the sample irradiated by the light source into basic color components, photoelectrically converts the light of the basic color components, and the data processing unit converts the light from the photoelectric conversion unit into basic colors. A photoelectric colorimeter that calculates the color value of a sample by converting information representing the amount of light of a component into a color space, comprising a memory means for storing information representing the amount of light of a basic color component of light from a concentration reference sample; Concentration calculation means is provided for calculating the concentration from information representing the amount of basic color components of light from the concentration reference sample stored in the memory means and information representing the amount of basic color components of light from the sample to be measured. A photoelectric colorimeter capable of measuring concentration.