JPS5919468A - Method for measuring luminance of fluorescent screen of cathode-ray tube - Google Patents

Abstract

PURPOSE:To attain the measuring easily in a short time, by visualizing an irradiated output measuring area with a signal pattern for luminance measurement and reading the irradiated area. CONSTITUTION:After a cathode-ray tube 1 to be measured is fitted, the operation of a deflecting system output adjusting device 22 is started and each power supply to operate the cathode-ray tube 1 is turned on. The irradiated area is adjusted into a prescribed size with an irradiated area reader 21 and a deflection system output adjusting device 22. A luminance signal is outputted from a signal generator 20 and applied to the cathode-ray tube 1 so that only the part measuring the irradiated output is measured. The irradiated output of the cathode-ray tube 1 is read at a luminance measuring device 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the brightness of a cathode ray tube fluorescent surface, particularly a cathode ray tube fluorescent surface that is stimulated to emit light using a deflecting means.

One of the important characteristics of cathode ray tubes is light output. That is, the light output of the most common cuff picture tube or various surface tubes used for displays is a particularly important factor when evaluating the performance of cathode ray tubes.

Referring to FIG. 1, a general method for measuring this optical output will be explained. There are at least three measurement conditions when measuring the light output of a cathode ray tube: the accelerating voltage (also called anode voltage, high voltage, etc.) applied to the fluorescent surface to operate the cathode ray tube, and the stimulation area ( (also called raster size) and stimulation current amount (also called TK).

Furthermore, depending on the type and characteristics of the fluorescent surface, the focus state and scanning speed of cathode rays and electron beams may also be specified. The stimulation area and stimulation current amount are stimulation density,
For example, it may be expressed in μA/d, but stimulation density is more commonly used.

Measurements are performed as follows based on these measurement conditions.

That is, the accelerating voltage (2) applied to the cathode ray tube (1)
The brightness signal jL (4) input to the electron gun (3) is emitted from the electron gun (3) as an electron beam (5) and is scanned by the deflection coil (6). Then, it hits a fluorescent surface (7) coated with a phosphor, stimulating the phosphor to emit light. This produces a light output from the faceplate of the multi-cathode ray tube (1). This light output (8) is detected by a measuring device (9), which displays the value of said condition as relative brightness or absolute brightness.

In such measurements, it is relatively easy to maintain and control the acceleration voltage and stimulation current, which are measurement conditions, while keeping and controlling the stimulation area, which is another condition, constant. This is the most difficult and most prone to measurement errors.

In other words, even if the accelerating voltage, stimulation current, etc. can be kept electrically constant, the stimulation area varies depending on the size of each cathode ray tube and the positioning of the deflection coil. It is necessary to check the dimensions using tools such as the following. For this reason, it is usually necessary to control the deflection signal α applied to the deflection coil (6) while checking the stimulation area, which makes measurement work cumbersome. Further, depending on the measuring device (9), the variable width of the deflection signal 00 is small, and it is often impossible to adjust the stimulation area to a measurable size. As described above, the conventional measurement method has a major drawback in the stage of setting the stimulation area.

Accordingly, the present invention provides a novel method for easily measuring the light output of a fluorescent surface. As a result of various studies on how to simplify the method of setting the stimulation area, we came up with a method that stimulates only the measurement site to emit light using the luminance signal, making it easier to set the area. Furthermore, we have come up with a means to make all parts except the light-emitting region into a non-light-emitting state, and to detect the boundary edge between the light-emitting region and the non-light-emitting region with a photoelectric element to automatically calculate or adjust the stimulation area. After deepening his knowledge and conducting various experiments, he obtained good results and completed this invention.

That is, an object of the present invention is to provide a cathode ray tube that can speed up and simplify brightness measurement by visualizing the area to be measured for luminescence output and reading the stimulation area using signals and patterns for brightness measurement. The purpose of this invention is to provide a method for measuring the brightness of a light surface.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of an apparatus used on the moon for the method for measuring the luminance of a cathode ray tube fluorescent surface according to the present invention, and the same parts as in FIG. 1 are given the same symbols and explanations are omitted. do.

In the figure, (1) is a signal generator for setting the stimulation area;
(2) is a light emission area reading device, (2) is a deflection system output adjustment device, (4) is a stimulation density adjustment calculation device, and is a digital display meter that indicates the stimulation current value. On the surface of the panel of the cathode ray tube (1), a plurality of photoelectric elements defining a predetermined area are mounted, as shown in FIG.

Next, a method of measuring brightness using the above device will be explained.

First, after installing the cathode ray tube (1) to be measured, start the operation of the deflection system output adjustment device) and turn on each power source for operating the cathode ray tube (1). . Next, the voltage value of the accelerating voltage (2) is set to a predetermined value, and the luminance signal (4) is applied to the signal generator (a). This luminance signal (4) is determined by the linearity of deflection and the image pattern 0, in which only the part whose light emission output is to be measured is emitted, as shown in Figure 4 (8) to (g). It has several points (2) for checking. Next, operate the stimulation density adjustment calculation device () and adjust so that a predetermined value of stimulation current flows by looking at the display meter (c). Further, a photoelectric element for setting a predetermined light emitting area is activated by a light emitting area reading device (Incorporated). Of course, if a predetermined stimulation density is to be achieved after measuring the area, all photoelectric elements are activated.

When each device is set to the measurement state in this way, the light emission area (to the light emission area reading device) and the deflection system output adjustment device) is instantly adjusted to a predetermined size, for example, 5 x 5c11. be done. The focus state of the light emitting surface and the linearity of deflection are manually adjusted visually. On the other hand, since the stimulation current and accelerating voltage have been adjusted to the conditions set at the beginning, all the various conditions for brightness measurement have been adjusted to constant values, and the luminescence output can be read using the predetermined brightness measurement device (9). I can do it. When measurements were carried out in this way, the measurement time was only about 115 seconds compared to the conventional method, and there was little variation in the measured values, and the accuracy was improved.

In the above embodiments, a monochrome type cathode ray tube was described, but the present invention is also applicable to color picture tubes and other types of cathode ray tubes for playback. Furthermore, even if some of the various devices, such as the light emitting area reader, are replaced manually, it will naturally be more advantageous when compared to the conventional measurement method, and various measurement specifications can be set by combining various devices in this way. It goes without saying that it can be done.

As explained above, according to the method for measuring the luminance of a cathode ray tube according to the present invention, the luminance output measurement area is visualized and the luminescence area is read using the signal pattern for luminance measurement. can be carried out easily and in a short time, and has an excellent effect in managing the brightness characteristics of the cathode ray tube.

[Brief explanation of the drawing]

1st Spring: An explanatory diagram of a conventional method for measuring the brightness of a cathode ray tube, FIG. 2 is a block diagram of a device used for the method of measuring the brightness of a cathode ray tube according to the present invention, and FIG. FIGS. 4(A) to 4(G) are front views showing examples of image patterns based on luminance measurement signals used in the above invention; FIGS. (1)...Cathode ray tube, (4)...Brightness signal, (5)
...electron beam, (7)...fluorescent surface, (9)...
Brightness measuring device, (2 ru... luminous area reading device, 0])
...Video pattern for brightness measurement. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno (1 other person) Figure 1 Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) A method for measuring the brightness of the fluorescent surface of a cathode ray tube by determining at least a predetermined applied voltage, a predetermined current, and a predetermined stimulation area to cause the fluorescent surface of the cathode ray tube to emit light, wherein the predetermined stimulus A method for measuring the luminance of a fluorescent surface of a cathode ray tube, characterized in that an area is set and included in a video signal input to the cathode ray tube, and the stimulation area is set according to a video pattern of the video signal. (2) The method for measuring the brightness of a cathode ray tube fluorescent surface as set forth in claim 1, wherein the video signal input to the cathode ray tube stimulates only the brightness measurement area to bring it into a light emitting state. (A cathode ray tube fluorescent surface according to claim 1, characterized in that the edge of a predetermined area in a 3X emission state is detected by a photoelectric element and a predetermined stimulation area is set and adjusted. Brightness measurement method.