JPS61182535A - Simple measuring device of brightness - Google Patents

Abstract

PURPOSE:To measure the brightness of an object to be observed by providing an arithmetic part for inputting signals from a scale reading part, an illuminance measuring part and an equivalent optical screen illuminance measuring part and calculating the brightness of a reference visual object matched at its brightness by an observer. CONSTITUTION:When the obsever matches a certain visual object with a reference object and determines a Munsell value on a scale display part 11, a signal correspond ing to the Munsell value is outputted from a scale reading part 12, converted into a code signal s1 by an A/D converter 13 and then sent to an arithmetic part memory 16. A signal outputted from an illuminance measuring part 14 is converted into a code signal s2 by an A/D converter 15. The equivalent optical screen illuminance measuring part 18 measures optical screen illuminance equivalent to an optical screen generated by an illuminance environment other than the display part 11 in the observer's eye-balls and a signal outputted from the measuring part 18 is converted into a code signal s3 by an A/D converter 19 and sent to the memory 16. Brightness values corre sponding to the code signals s1-s3 are stored in the memory 16. Therefore, the bright ness values can be outputted and displayed on a brightness display part by accessing the memory 16.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for measuring brightness (the "brightness" perceived by humans), which is a standard for evaluating illumination visual environments and displays.

BACKGROUND ART The brightness of a certain visual object is determined by the brightness of the visual object Lo.
It has been clarified that the luminance difference discrimination coefficient ΔLmin corresponding to the adaptation state of the eyes of the person viewing it is expressed by the following equation.

B=0.8 ((Lo/ΔLmin)-1)...
(1) It is also known that the brightness difference discrimination ΔLmin is determined by the observer's foveal adaptation brightness Laf and the equivalent light screen brightness Leq generated by the brightness of the observer's peripheral visual field.

In conventional simple brightness measuring devices, equation (1) is derived from the idea that the brightness of an achromatic color chart under certain observation conditions is used as a standard, and the brightness is valued by the Munsell value of that color chart. Therefore, the brightness of the object was measured by an observer by matching the brightness of the actual object with an achromatic color chart under conditions similar to the observation conditions described above.

FIG. 3 is a block diagram showing an embodiment of a conventional brightness simple measuring device. In FIG. 3, reference numeral 1 denotes a scale display section which presents the observer with a reference visual object for brightness matching. The reference visual object has a Munsell value of 0.
A Munsell gray scale with 5 intervals is used. Reference numeral 2 denotes a scale reading section which reads the signal (Munsell value) of the reference visual object presented on the scale display section. Therefore, when an observer determines the Munsell value of the scale display section 1 by matching the brightness of a certain visual object and a reference visual object, the scale reading section 2 outputs a signal corresponding to the Munsell value. be done. This signal is converted into a code signal S1 by the A/D converter 3 and output. Reference numeral 4 denotes an illuminance measurement section, and the signal from this section is converted into a code signal S2 by an A/D converter 5 and sent to a calculation section memory 6 together with Sl. The brightness value calculated in advance based on the code signal S1 corresponding to the Munsell value and the code signal S2 corresponding to the illuminance value is stored in the calculation unit memory 6. Therefore, by accessing the calculation unit memory 6, the brightness value is stored. The value of is output,
It is displayed on the brightness display section 7.

The specific configuration of the scale display section 1 will be described below. The scale presentation section 11 is composed of a visual object having a visual angle of 2 degrees and a surrounding background having a visual angle of 20 degrees and a Munsell value of 5 (achromatic color). An achromatic color chart is presented to the viewing object as a reference viewing object. When this scale presentation section 11 is illuminated with an illuminance of 1000fx,
The observation condition that the brightness of the reference object is equal to its Munsell value is satisfied.

Next, FIG. 4 shows an example of the relationship between the Munsell value of the reference visual object, brightness, and illuminance. Using FIG. 4, the brightness value is determined from the output signals from the scale reading section 2 and the illuminance measuring section 4, that is, the Munsell value and the illuminance.

Problems to be Solved by the Invention In such conventional devices, there is a problem in that the brightness value differs depending on the brightness environment other than the scale display section.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a scale display unit that presents a reference visual object for brightness matching to an observer, and a standard that is presented on the scale display unit. There is a scale reading section that reads signals corresponding to the visible object, an illuminance measuring section that measures the illuminance at the scale display section, and an illuminance measurement section that measures the illuminance caused by the brightness environment other than the scale display section in the eyeball of the observer looking at the scale display section. an equivalent light curtain brightness measurement device that measures light curtain brightness equivalent to the light curtain in which the light curtain is located, a signal from the scale reading section, a signal from the illuminance measurement section, and a signal from the equivalent light curtain brightness measurement device. , a calculation unit that calculates the brightness of the reference visual object whose brightness has been matched by the observer, and a brightness display unit that displays the brightness value.

Effect of the Invention With the above-described configuration, the present invention allows the observer to easily adjust the brightness of the visual object by matching the brightness of the visual object and the reference visual object, regardless of the brightness state of the visual field other than the scale display section. is measured.

Embodiment FIG. 1 is a block diagram showing an embodiment of a simple brightness measuring device of the present invention.

Hereinafter, a simple brightness measuring device according to the present invention will be explained based on FIG. In FIG. 1, reference numeral 11 denotes a scale display section that presents a reference visual object for brightness matching to the observer. A Munsell gray scale with an interval of 0.5 in the Munsell value is used for the reference visual object.

Reference numeral 12 denotes a scale reading section which reads the signal (Munsell value) of the reference visual object presented to the scale presentation section. Therefore, the scale display section 11
When the Munsell value of is determined, the scale reading section 12 outputs a signal corresponding to the Munsell value. This signal is converted into a code signal S1 by the A/D converter 13 and sent to the arithmetic unit memory 16. 14 is an illuminance measuring section, and the signal from here is sent to an A/D converter 15 as a code signal S.
2 and sent to the calculation unit memory 16. The equivalent light curtain brightness measuring unit 18 measures the light curtain brightness equivalent to the light curtain generated by the brightness environment other than the scale display part in the eyeball of the observer looking at the scale display part, and the signal from this is A. The code signal S3 is converted by the /D converter 19 and sent to the arithmetic section memory 16. The calculation unit memory 16 stores brightness values calculated in advance based on the code signal S1 corresponding to the Munsell value, the code signal S2 corresponding to the illuminance value, and the equivalent light curtain luminance caused by the luminance environment other than the scale display section. Therefore, when the arithmetic section memory 16 is accessed, the brightness value is output and displayed on the brightness display section 17.

An example of data stored in the calculation section memory 16 is shown in FIG. In Figure 2, the illuminance is 1000J! FIG. 4 is a relationship diagram between the Munsell value of the reference object and the equivalent light screen luminance according to the brightness and the luminance state of the visual field other than the scale display section at x.

Effects of the Invention As described above, according to the present invention, the brightness of a visual object can be measured with a simple configuration regardless of the brightness environment other than the scale display section, and is extremely useful in practice.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a simple brightness measuring device in an embodiment of the present invention, and FIG. 2 is a relationship between the Munsell value at an illuminance of 10001 and the equivalent light screen brightness depending on the brightness and the brightness state of the visual field other than the scale display section. 3 is a block diagram showing a conventional brightness measuring device, and FIG. 4 is a diagram showing the relationship between Munsell value, brightness, and illuminance. 11--Scale display section, 12--Scale reading section, 13--A/D converter, 14--Illuminance measurement section, 15--=-A/D converter, 16-Computation section memory , 17--Brightness display section, 18--Equivalent light screen brightness measurement section, 19--A/D converter.

Claims (1)

[Claims] A scale display section that presents a reference visual object for brightness matching to the observer, a scale reading section that reads a signal corresponding to the reference visual object presented on this scale display section, and an illuminance at the scale display section. an equivalent light screen brightness measuring device that measures light screen brightness equivalent to a light curtain generated by a brightness environment other than the scale display section in the eyeball of an observer looking at the scale display section; a calculation unit that inputs a signal from the scale reading unit, a signal from the illuminance measurement unit, and a signal from the equivalent light curtain brightness measurement device, and calculates the brightness of the reference visual object whose brightness has been matched by the observer; , and a brightness display section that displays the brightness value.