JPH05118920A - Brightness measuring apparatus for simple use - Google Patents

Abstract

PURPOSE:To provide an apparatus to simply measure a human feeling brightness which is necessary for planning and evaluating illuminated visual environments and image production apparatuses. CONSTITUTION:A scale indicating part 1 is composed of a standard visual object with a visual size 2 deg. and dark background and as a light source a halogen lamp is used and as standard visual object one diffused by an opalescent plate is used. The standard visual object and a visual object are optically separated. The standard visual object 2 is a light modulation controlling part to change the brightness and here an observer carries out matching the brightness of visual object (environment, lamp, etc.) and the standard visual object. The signal from a brightness measuring part 3 is converted into a code signal S1 by a first A/D transformer 4 and sent to a memory 5 of a computing part. The brightness value previously computed based on the code signal S1 corresponding to the brightness is stored in the memory 5 of the computing part. Consequently, by the access to the memory 5 of the computing part, the value of the brightness is sent out and displayed on a displaying part 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination visual environment and a device for measuring the brightness (hereinafter referred to as "brightness") perceived by humans necessary for designing and evaluating video equipment.

[0002]

2. Description of the Related Art It is clear that the brightness of a certain visual object is expressed by (Equation 1) as a function of the luminance Lo of the visual object and a luminance difference discrimination threshold .DELTA.Lmin corresponding to the adaptation state of the viewer. Has been

[0003]

[Equation 1]

It is known that the brightness difference discrimination threshold ΔLmin is determined by the fovea adaptation brightness Laf of the observer and the equivalent light curtain brightness Leq generated by the brightness of the observer's peripheral visual field.

In the conventional simple brightness measuring device,
Since (Equation 1) is derived from the idea that the brightness of an achromatic color chip placed under a certain observation condition is used as a reference, and that brightness is valued by the value of the Munsell value of that color patch. The observer measured the brightness of the visual object by matching the brightness of the actual visual object and the achromatic color chip under conditions similar to the above observation conditions.

FIG. 3 shows the configuration of a conventional brightness measuring device. In FIG. 3, the scale presenting unit 1 presents the brightness matching reference visual target object to the observer. The scale presentation unit 1 is composed of a visual dimension of 20 ° and a Munsell value 5 (achromatic color) background portion. The Munsell gray scale with 0.5 Munsell values is used as the reference visual target. The scale reading unit 8 reads the signal (Munsell value) of the reference visual target presented by the scale presenting unit 7. Therefore, when the observer performs brightness matching between a certain visual target object and a reference visual target object and determines the Munsell value of the scale presenting unit, the scale reading unit 8 outputs a signal corresponding to the Munsell value. This signal is converted into a code signal S1 by the second A / D converter 8 and output. The illuminance measuring unit 9 sends the signal from here to the third A
The code signal S2 is converted by the / D converter 10 and sent to the arithmetic unit memory 5 together with S1. The brightness value calculated in advance based on the code signal S1 corresponding to Munsell value and S2 corresponding to Munsell value is stored in the arithmetic unit memory 5. Therefore, if the arithmetic unit memory 5 is accessed, the brightness value is output.

[0007]

In such a conventional apparatus, the reflectance from the background of the object may affect the brightness sensation of the observer, and particularly when the effect is brightness 3 or less. There was a problem of getting bigger.

[0008]

In order to solve the above problems, the present invention provides a scale presenting section which is optically separated from a visual object, and a dimming control for varying the brightness of the scale presenting section. Section, a brightness measuring section for measuring the brightness in the scale presenting section, a calculating section for calculating the brightness by the output of the brightness measuring section, and a display section for displaying the output of the calculating section. While silently controlling the dimming control unit to match the brightness of the scale presenting unit and the brightness of the visual target, the brightness measuring unit, the brightness of the scale presenting unit at that time. Is measured, and the brightness is configured based on the measured luminance and the calculation unit.

[0009]

According to the present invention, with the above configuration, the background of Munsell value 5 can be eliminated, and it becomes easy and accurate for the observer to match the brightness of the visual object and the reference visual object. The brightness of the visual target can be easily measured.

[0010]

EXAMPLE An example of measuring the brightness of an object to be viewed (environment, lamp, etc.) by an observer with the simple brightness measuring apparatus of the present invention will be described below with reference to FIG. 1 showing its block configuration. .. In FIG. 1, the scale presenting unit 1 is composed of a reference visual object having a visual angle of 2 ° and a substantially dark background, and is optically separated from the visual object. A halogen lamp is used as a light source, and a light source diffused by a milky white plate is used as a reference visual object. The light source may be a fluorescent lamp or a xenon lamp. Reference numeral 2 denotes a dimming control unit that changes the brightness. The observer adjusts the dimming control unit 2 to perform brightness matching between the visual target and the reference visual target. The luminance of the reference visual object after the matching is measured by the luminance measuring section 3, and the signal from the luminance measuring section 3 is converted into the code signal S1 by the first A / D converter 4 and sent to the arithmetic section memory 5.

FIG. 2 is a diagram showing the relationship between the brightness B of the visual target object and the luminance L0 of the visual target object obtained by the subject experiment. The arithmetic unit memory 5 stores the relationship between the brightness B of the visual target of FIG. 2 and the luminance Lo of the visual target of FIG. 2, and stores the code signal S1 sent from the first A / D converter 4. Based on this, the brightness value of the visual target is calculated. The brightness value calculated in the calculation unit memory 5 is displayed on the display unit 6.

[0012]

As described above, according to the present invention, the brightness of the visual object can be measured with a simple structure, which is practical. In particular, it is effective for evaluating the brightness of the self-luminous light source and for evaluating the illumination in the tunnel.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a simple brightness measuring device according to an embodiment of the present invention.

FIG. 2 is a relationship diagram between brightness and brightness.

FIG. 3 is a configuration diagram of a conventional brightness measuring device.

[Explanation of symbols]

 1 Scale presenting section 2 Dimming control section 3 Luminance measuring section 4 First A / D converter 5 Computing section memory 6 Display section 7 Scale reading section 8 Second A / D converter 9 Illuminance measuring section 10 Third A / D converter

Claims (1)

[Claims] 1. A scale presenting unit that is optically separated from a visual object, a dimming control unit that changes the brightness of the scale presenting unit, and a luminance measurement that measures the brightness of the scale presenting unit. Section, a calculation section for calculating brightness by the output of the brightness measurement section, and a display section for displaying the output of the calculation section. The observer controls the dimming control section while gazing at the scale. The brightness of the visual target is matched with the brightness of the video presentation unit, the brightness measurement unit measures the brightness of the scale presentation unit at that time, and the brightness is based on the measured brightness. A simple brightness measuring device characterized by being calculated by a calculation unit.