JPH1023471A - White balance measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a white balance measuring device capable of measuring the white balance of the whole screen of each monitor from a position apart from the screen. SOLUTION: When a pattern signal P is inputted from a video signal generating circuit 24 to a television 100, the reference white part of the pattern signal P is displayed on a screen 101. when the screen 101 is picked up by an image pickup lens 11, its optical signal is divided into R, G and B light components by a spectroscope 12 and converted into analog electric signals AR, AG, AB by respective photosensors 13R, 13G, 13B. The signals AR, AG, analog/digital converters 21R, 21G, 21B and measured by a level judging circuit 22. Consequently picture signals VR, VG, VB corresponding to the measured values are outputted to a display device 23 and the R, G and B levels of the screen 101 are displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a white balance measuring device for measuring whether or not a monitor screen emits a reference white light.

[0002]

2. Description of the Related Art Generally, in a television production line, it is measured whether or not a television screen emits a reference white light, and the levels of red, green and blue are adjusted according to the measurement result. Are adjusted to emit light at a predetermined white balance. Conventionally, this type of white balance measurement technique is to adjust a white balance by bringing a small pickup having a built-in photo sensor into close contact with a television screen and measuring a light emission level of a part of the screen. Some of such pickups are provided with a finder, and the finder allows the user to confirm the measurement area of the pickup.

[0003]

However, the above-mentioned conventional measuring technique has the following problems. Since this technique measures only a part of the television with a pickup, the measurement range is narrow. For this reason, the white balance of the entire screen cannot be accurately measured. Also, when measuring the distortion of the screen, etc., a part of the screen is hidden by the pickup.To accurately measure the distortion of the screen, etc., a mechanism to move the pickup away from the screen during the measurement is required. Must be specially provided. Further, in the technique of bringing the pickup into close contact with the screen of the television, a trace of close contact of the pickup may remain on the screen of the product. Further, in a device such as a rear projector having a soft screen surface, if the pickup is pressed against the screen surface, the screen is deformed and accurate measurement cannot be performed. In addition, in the case where the finder is attached to the pickup, measurement for each television cannot be performed, and a defective product may be generated due to a positional shift of the television set on the production line.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a white balance measuring apparatus capable of measuring the white balance of the entire screen at a position away from the screen of each monitor. And

[0005]

According to a first aspect of the present invention, there is provided a white balance measuring device for generating a predetermined video signal for making a monitor screen white. An optical unit that captures an image of the monitor screen; a light splitting unit that splits light signals from the optical unit into red, green, and blue light signals; and a red, green, and blue light signal from the light splitting unit that emits red, green, and blue light signals. A photoelectric conversion unit that converts the signals into green and blue electric signals, and measures the levels of the red, green, and blue electric signals from the photoelectric conversion units, and generates red, green, and blue image signals corresponding to the measured values. A configuration is provided that includes a level determination unit and a display unit that displays the red, green, and blue image signals generated by the level determination unit.

According to a second aspect of the present invention, in the white balance measuring device according to the first aspect, the photoelectric conversion unit converts the red, green, and blue optical signals from the spectral unit into red, green, and blue digital electric signals. The level determination unit measures the values of the red, green, and blue digital electric signals from the light conversion unit, and generates red, green, and blue image signals corresponding to the measured values. Configuration.

According to the first aspect of the present invention, when a predetermined video signal for whitening the monitor screen is generated by the video signal generation unit and the monitor screen is imaged by the optical unit, the optical signal is converted by the spectroscopy unit. It is split into red, green and blue light signals. And
The red, green, and blue light signals from the light splitting unit are converted into red, green, and blue electric signals in the photoelectric conversion unit. Then, the level determination unit measures the levels of the red, green, and blue electric signals, and generates red, green, and blue image signals corresponding to the measured values. Each level is displayed on the display unit based on the red, green, and blue image signals.

According to the second aspect of the present invention, in the photoelectric conversion unit, the red, green, and blue light signals from the spectroscopy unit are converted into red, green, and blue digital electric signals. The values of the red, green, and blue digital electric signals are measured, and red, green, and blue image signals corresponding to the measured values are generated.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a white balance measuring device according to one embodiment of the present invention. As shown in FIG. 1, the white balance measuring device of the present embodiment has a configuration roughly divided into a movable unit 1 and a fixed unit 2.

The movable section 1 includes an imaging lens 11 in a housing 10.
(Optical unit), a spectroscope 12 (spectral unit), and three photosensors 13R, 13G, and 13B (photoelectric conversion units). The imaging lens 11 is an optical lens system for imaging the screen 101 of the television 100 as a monitor. The spectroscope 12 includes the imaging lens 11
Light signals (hereinafter referred to as "R") and green (hereinafter referred to as "R").
This is a device for separating light signals of “G” and blue (hereinafter, described as “B”) into light signals, and is configured by a prism, and is disposed at a subsequent stage of the imaging lens 11. Photo sensor 1
Reference numerals 3R, 13G, and 13B denote elements for converting an optical signal separated by the spectroscope 12 into an analog electric signal. The photosensor 13R converts the R optical signal into an R analog electric signal AR. The sensor 13G converts the G optical signal into a G analog electric signal AG,
At B, the B optical signal is converted to a B analog electrical signal AB. The movable section 1 having such a configuration is attached to the XY table 3, and can be moved by the XY table 3 in a plane perpendicular to the plane of FIG.

On the other hand, the fixed section 2 includes three amplifiers 20R,
20G, 20B and three analog / digital converters 21R, 21G, 21B (denoted as "A / D" in FIG. 1)
, A level determination circuit 22 (level determination unit), a display device 23 (display unit), and a video signal generation circuit 24 (video signal generation unit). Amplifier 20R, 2
0G and 20B are photo sensors 13R, 13G and 13B
And the photosensors 13R,
Analog electric signals AR, AG, A from 13G, 13B
A device that amplifies and outputs B. The analog-to-digital converters 21R, 21G, and 21B are connected to the amplifier 20R,
The analog electric signals AR, AG, AB amplified by the analog-to-digital converters 21R, 21G, 21B are respectively connected to the output terminals of 20G, 20B, and are converted into R digital signals DR, G digital signals DG, B. It is a device that converts to a signal DB. The level determination circuit 22
Analog-to-digital converters 21R, 21G, 21B
Of the digital signal DR from the analog-to-digital converters 21R, 21G, and 21B.
Measure the value of DG, DB, R, G, B corresponding to the measured value
Is a circuit that generates the image signals VR, VG, and VB of FIG. The display device 23 is a device that displays the levels of R, G, and B on the screen 101 over time based on the image signals VR, VG, and VB input from the level determination circuit 22. The video signal generation circuit 24 is a circuit that generates a pattern signal P (video signal). FIG. 2 is a schematic diagram of the pattern signal P generated by the video signal generation circuit 24. As shown in FIG. 2, the pattern signal P has a reference white portion W in the center, and as shown in FIG. 1, the output terminal of the video signal generation circuit 24 is connected to the TV receiver 102 of the television 100. When the pattern signal P is sent from the video signal generating circuit 24 by connecting to the video input terminal, the reference white portion W is projected on the screen 101 of the television 100.

Next, the operation of the white balance measuring device of the present embodiment will be described. FIG. 3 is a schematic diagram showing a positional relationship between the imaging range 11 a of the imaging lens 11 and the screen 101, and FIG. 4 is a schematic diagram showing a screen of the display device 23. In FIG. 1, the movable unit 1 of the white balance measuring device is arranged apart from the screen 101 of the television 100, and the output terminal of the video signal generation circuit 24 of the fixed unit 2 is connected to the video input terminal of the TV receiver 102 of the television 100. Connect to Then, when the pattern signal P shown in FIG. 2 is sent from the video signal generation circuit 24, the reference white portion W is projected on the entire screen 101 of the television 100.

In this state, when an image is taken by the imaging lens 11, the optical signal is split into R, G, B optical signals by the spectroscope 12, and the split R, G, B optical signals are
The photosensors 13R, 13G, and 13B convert the signals into analog electric signals AR, AG, and AB. When these analog electric signals AR, AG, and AB are input to the fixed unit 2, they are amplified by the amplifiers 20R, 20G, and 20B.
Analog-to-digital converters 21R, 21G, 21B
, And are converted into R digital signals DR, G digital signals DG, and B digital signals DB. And
Each value of the digital signals DR, DG, and DB is measured by the level determination circuit 22, and R, G, and B image signals VR, VG, and VB corresponding to the measured values are generated. This allows
R, R on the screen 101 corresponding to the image signals VR, VG, VB
Each level of G and B is displayed on the display device 23 with time.

At this time, as shown in FIG. 3A, when the imaging range 11a of the imaging lens 11 is out of the screen 101 of the television 100, the reference white portion W displayed on the screen 101 is displayed. Is hardly incident on the imaging lens 11. Therefore, the digital signals DR, DG, D
The value of B is very small, and the level display of R, G, and B based on the image signals VR, VG, and VB output from the level determination circuit 22 to the display device 23 is as shown in FIG. Very short. Therefore, the measurer can see that the imaging range 11a is out of the screen 101 by looking at this display.

In order to make the imaging range 11a coincide with the screen 101, the movable section 1 is moved by the XY table 3 in a plane perpendicular to the plane of FIG. The movable part 1 is moved, and FIG.
As shown in (1), when the imaging range 11a begins to overlap the screen 101, the light of the overlapping reference white portion W enters the imaging lens 11, and the values of the digital signals DR, DG, and DB increase according to the overlapping area. . Therefore, the imaging range 11
As the overlapping area between the “a” and the screen 101 increases,
The levels of R, G, and B increase as shown in FIG.

Further, the movable part 1 is moved, and FIG.
As shown in the figure, when the imaging range 11a completely matches the screen 101, the light of all the reference white portions W enters the imaging lens 11, and the values of the digital signals DR, DG, and DB become maximum,
The R, G, and B levels also extend as shown in FIG. Therefore, the measurer moves the movable unit 1 while watching this display, and measures the current white balance of the screen 101 by positioning the movable unit 1 when the levels of R, G, and B are maximized. be able to.

As a result of this measurement, when it is determined that the white balance of the screen 101 is weak, the volume of the white balance adjustment circuit of the TV receiver 102 is adjusted, and the levels of R, G, and B are viewed while looking at the display device 23. I will strengthen.
Then, as shown in FIG. 4D, when the levels of R, G, and B reach the broken line portions, and the white balance reaches an optimal value, for example, 9300K, the volume adjustment is ended.

The measuring operation as described above is performed on the television 10
0, and can accurately measure each television 100. Also,
The distortion measurement of the screen 101 can be performed by disposing a distortion measuring device between the television 100 and the movable unit 1.

The present invention is not limited to the above embodiment, and various modifications and changes can be made within the scope of the invention. For example, in the present embodiment, the amplifiers 20R, 20G, and 20B are provided in the fixed unit 2, but the high-sensitivity analog-to-digital converters 21R, 21G, and 2B are provided.
1B and the level determination circuit 22, the amplifier 20R,
It is not necessary to provide 20G and 20B. In the present embodiment, the analog-to-digital converters 21R, 21G,
21B is provided to convert the analog electric signals AR, AG, AB into digital signals DR, DG, DB. However, the present invention is not limited to this, and the level determination circuit 22 directly outputs the analog electric signals AR, AG, AB. AB level is measured, and image signals VR, VG, VB corresponding to the measured value are measured.
May be generated.

[0020]

As described above in detail, according to the white balance measuring apparatus of the present invention, the screen of the monitor is imaged by the optical unit, and the red, green and blue levels of the screen are displayed on the display unit. Therefore, the white balance of the entire monitor screen can be accurately measured. In addition, since the optical unit can be measured away from the monitor screen, the apparatus does not hinder the measurement of the distortion of the screen. As a result, unlike the related art, a special mechanism for moving the pickup is not required, so that the cost can be reduced and the efficiency of the screen distortion measurement operation can be increased. In addition, since the measurement can be performed without bringing the optical unit into contact with the monitor screen, traces of measurement such as traces of close contact with the pickup are not left on the monitor screen. Then, since the screen is not deformed at the time of measurement of the rear projector or the like, accurate measurement can be performed even with such an apparatus. Further, since the measurement can be performed for each monitor, even if the monitor set is displaced on the production line, the occurrence of defective products due to the displacement does not occur.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a white balance measuring device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a pattern signal generated by a video signal generation circuit.

3A and 3B are schematic diagrams illustrating a positional relationship between an imaging range of an imaging lens and a television screen, wherein FIG. 3A illustrates a state in which the imaging range is out of the television screen, and FIG. FIG. 3C shows a state in which the imaging range partially overlaps the television screen, and FIG. 3C shows a state in which the imaging range completely matches the television screen.

4A and 4B are schematic diagrams illustrating a screen of a display device. FIG. 4A illustrates R, G, and B levels in a state where an imaging range is out of a television screen, and FIG. R, G, B when the imaging range partially overlaps the TV screen
FIG. 4C shows the levels of R, G, and B when the imaging range completely matches the television screen, and FIG. 4D shows the optimal state of the white balance.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Movable part, 2 ... Fixed part, 11 ... Imaging lens, 12 ... Spectroscope, 13R, 13G, 13
B: Photo sensor, 21R, 21G, 21B ...
· Analog-digital converter, 22 · · · level determination circuit, 23 · · · display device, 24 · · · video signal generation circuit, 100 · · · television, 101 · · ·
・ Screen, P ・ ・ ・ Pattern signal, W ・ ・ ・ Reference white part.

Claims (2)

[Claims] 1. An image signal generating section for generating a predetermined image signal for making a monitor screen white, an optical section for capturing an image on the monitor screen, and a light signal from the optical section for red, green and blue light. A spectroscopy unit for splitting the light into signals, a photoelectric conversion unit for converting the red, green and blue light signals from the spectroscopy unit into red, green and blue electrical signals, and a red, green and blue light signal from the photoelectric conversion unit. A level determining unit that measures the level of the electric signal and generates red, green, and blue image signals corresponding to the measured value; and a display unit that displays the red, green, and blue image signals generated by the level determining unit. A white balance measuring device, comprising: 2. The white balance measuring device according to claim 1, wherein the photoelectric conversion unit converts red, green and blue light signals from the spectroscopic unit into red, green and blue digital electric signals. Wherein the level determination unit measures the values of the red, green, and blue digital electric signals from the light conversion unit and generates red, green, and blue image signals corresponding to the measured values. A white balance measuring device, characterized in that: