JPS63125976A - Visual environment evaluator for display device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a visual environment evaluation device for evaluating the visual environment of a room in which a display device with a positive display screen is installed.

2. Description of the Related Art In recent years, with the development of CRT displays, liquid crystal displays, etc., various display devices using these as display devices have been introduced into indoor facilities where conventional office work was performed.

Generally, the display device itself is designed so that displayed contents can be viewed accurately and comfortably in a certain limited viewing environment. For this reason, if the display device is used in a different viewing environment than the one assumed for the vehicle, for example, if the display is used in a situation where high-luminance objects such as lighting or windows are reflected on the screen, the display may become difficult to see or become bothersome. etc., it is not always possible to visually confirm the displayed content accurately and comfortably. Even if the visibility of the display device itself is evaluated in this way, the visibility of the display device changes depending on the viewing environment in which it is viewed, so it is not an evaluation of the visibility in the actual viewing environment in which the display device is used. There wasn't. For this reason, for example, when a display device is used with a high-brightness object reflected on the screen, there is no indicator that can be used to evaluate whether the viewing environment in which the display device is viewed is one that provides sufficient visibility. The visibility (VL) of a reflected image of a high-luminance object (lighting equipment, window, etc.) reflected on the screen of a display device is used as a physical quantity that has a good correlation with the evaluation value. Visibility is calculated using the following relational expression.

VL=CobJ/Cthre CobJ= (L o L b ) /YCth, e
=0.05936[(1,639/Y)O・'+1
12-5Y = L b + Le q where Lo: Brightness of a high-brightness object reflected on the screen of the display device Lb: Brightness of the background part of the screen of the display device Leq: The display device was placed in the environment to be evaluated As is clear from the formula for calculating the luminance of a light curtain equivalent to the scattered light curtain produced in the eyes of the observer who sees it, visibility is the difference between the brightness of an object under a certain environment and the brightness of the object when observed under that environment. It is expressed as the ratio to the minimum value of luminance contrast necessary for a person to be able to see the object.

Display devices generally have two types of screen modes: negative display and positive display. Even if the viewing environment of the room in which the display device is installed is the same, it is not possible to determine whether the screen of the display device is negative display or positive display. Therefore, the visual environment evaluation value will be different. Therefore, in order to evaluate the visual environment of a display device with positive display, it was necessary to change the screen of the display device from negative display to positive display and measure the visibility.

Problem to be Solved by the Invention When the display screen of a display device is changed from positive display to negative display, it is determined whether the visual environment of the display device is a visual environment in which sufficient visibility can be obtained. There was no way to predict and evaluate the situation.

Means for Solving the Problems In order to solve the above problems, the present invention uses a visual environment evaluation value corresponding to the visibility of a reflected image of a high-luminance object reflected on a negative display screen of a display device, and a We clarified the relationship between the visual environment evaluation value, which corresponds to the visibility of the reflected image of a high-brightness object reflected on a positive display screen, and used this relationship to determine whether the display screen has a sufficient visual environment for negative or positive display devices. This is a system that predicts and evaluates whether the viewing environment is such that visibility can be obtained from the visibility of the negative display screen.

According to the above-described configuration, the present invention measures the visibility of a high-brightness object reflected on the negative display screen of a display device, and uses the visibility to determine whether the same high-brightness object reflected on the positive display screen of the same display device is measured. It is possible to obtain a visual environment evaluation value corresponding to the visibility of the reflected image of , and evaluate whether the visual environment is a visual environment that provides sufficient visibility to view the positive display device.

Embodiment FIG. 1 is a block diagram showing an embodiment of a visual environment evaluation device for a display device according to the present invention. In FIG. 1, 1 is a reflected image brightness measurement unit, 2 is a background brightness measurement unit, 3 is an equivalent light curtain brightness measurement unit, 4 is a visibility calculation unit, 5 is a negative display screen visual environment evaluation value conversion unit, 6 is a visual environment evaluation value conversion unit for the positive display screen, and 7 is a display unit. FIG. 2 is a characteristic diagram of the visual environment evaluation value converter for a negative display screen. This figure is a characteristic diagram showing the relationship between visibility and visual environment evaluation value using several existing display devices with different anti-reflection treatments on their display screens. Here, the visual environment evaluation value 0 means that the brightness in the area with a cutoff angle of 60 degrees or more is 200 cd/m2.
The visual environment evaluation value of the display device is shown when the lighting equipment regulated below is reflected on the negative display screen of the display device that has not been subjected to anti-reflection treatment. The visual environment evaluation value shown here represents a relative visual environment evaluation value based on this, and the larger the visual environment evaluation value, the better the visibility for viewing the display device. This means that the viewing environment is FIG. 3 is a characteristic diagram of the visual environment evaluation value converter for a positive display screen. This figure also uses several existing display devices with different anti-reflection treatments for their display screens, and calculates the visual environment evaluation value corresponding to the visibility of the reflected image of a high-brightness object reflected on the negative display screen of the display device.
FIG. 7 is a characteristic diagram illustrating the relationship between the visibility of a reflected image of the same high-intensity object reflected on the positive display screen of the same display device and the visual environment evaluation value corresponding to the visibility. The visual environment evaluation values are the same as those used in FIG.

The operation of the visual environment evaluation device for a display device of this embodiment configured as described above will be described below with reference to FIG.

The reflected image brightness measurement unit 1 measures the brightness Lo of a high-brightness object reflected on the screen of a display device, and outputs a signal corresponding to the brightness. The background brightness measuring unit 2 measures the brightness Lb of the background part of the screen of the display device, and outputs a signal corresponding to the brightness of the background part. The equivalent light curtain luminance measuring unit 3 measures the light curtain luminance (equivalent light curtain luminance L
6Q) and outputs a signal corresponding to the equivalent light screen brightness.

The visibility calculation unit 4 calculates the signal from the reflected image brightness measurement unit 1, the signal from the background brightness measurement unit 2, and the equivalent light curtain brightness measurement unit 3.
The visibility (■L) of the reflected image of the high-intensity object reflected on the screen of the display device is calculated from the signal from the display device, and a signal corresponding to the value is output.

The visual environment evaluation value conversion unit 5 for the negative display screen calculates a visual environment evaluation value corresponding to visibility from the signal from the visibility calculation unit 4 according to the characteristics shown in FIG. 2, and outputs a signal corresponding to the value. do. The visual environment evaluation value conversion unit 6 for the positive display screen converts the signal from the visual environment evaluation value conversion unit 5 for the negative display screen into a visual environment evaluation value for the positive display screen according to the characteristics shown in FIG. Output the corresponding signal. The display section 7 displays the contents of the signal from the visual environment/environmental evaluation value conversion section of the positive display screen.

Effects of the Invention According to the present invention, it is possible to determine whether the visual environment of a person viewing a display device with a positive display screen is such that the content displayed on the display screen of the display device can be viewed accurately and comfortably. Predictive evaluation can be made from the visibility value of the display screen.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a visual environment evaluation device for a display device according to an embodiment of the present invention, FIG. 2 is a characteristic diagram of a visual environment evaluation value conversion unit for a negative display screen of the same device, and FIG. FIG. 6 is a characteristic diagram of a visual environment evaluation value conversion unit for a positive display screen. DESCRIPTION OF SYMBOLS 1... Reflected image brightness measurement unit, 2... Background brightness measurement unit, 3... Equivalent light curtain brightness measurement unit, 4... Visibility calculation unit, 5... Visual environment of negative display screen evaluation value converter,
6...Visual environment evaluation value conversion unit for positive display screen, 7
・・・Name of Display Department Agent Patent Attorney Toshio Nakao Haka1
Name figure 2

Claims (1)

[Claims] A reflected image brightness measurement unit that measures the brightness of a reflected image of a high-brightness object reflected on the screen of the display device, a background brightness measurement unit that measures the brightness of the background of the screen of the display device, and an observer viewing the display device. An equivalent light curtain brightness measurement unit measures the light curtain brightness equivalent to the scattered light curtain generated in the eyeball, and the visible reflection image is calculated from the signal from the reflected image brightness measurement unit and the signal from the equivalent light curtain brightness measurement unit. a visibility calculation unit that calculates the visibility, a negative display screen visual environment evaluation value conversion unit that converts the signal of the visibility calculation unit into a negative display screen visual environment evaluation value, and a negative display screen visual environment evaluation value conversion unit A visual environment evaluation device for a display device, comprising: a positive display screen visual environment evaluation value conversion unit that converts a signal from the above into a positive display screen visual environment evaluation value; and a display unit that displays the positive display device visual environment evaluation value. .