JPS59114984A - Color picture reproducer of index system - Google Patents

Abstract

PURPOSE:To adjust the white chromaticity of each color picture reproducer of index system at a desired chromaticity point by superposing the detected index signal on an index system video signal after adjusting the amplitude and phase of said index signal and driving an index tube. CONSTITUTION:When the white color is reproduced on the tube surface, the amplitude is set at zero for the carrier chrominance signal which is impressed to a terminal 8. Therefore no signal emerges at the output terminal of a multiplier 9. However a fixed signal coincident with the triplet frequency is obtained at the output terminal of a phase control circuit 14. Thus the output signal of the circuit 14 is added 15 to the output signal of an adder 12 to drive an index tube. As a result, a fixed hue is reproduced on the index tube in response to a fixed signal despite reception of a white signal. Therefore the reproduced hue can be selected at an optional chromaticity point from the adjusting state of an amplitude adjusting circuit 13 and the circuit 14 respectively.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an index method color image reproduction device,
In particular, the present invention relates to a circuit configuration for setting the white chromaticity point to an optimum state.

[Prior art]

The principle of a color image reproduction device using the index method is well known, and will be briefly explained below.

In this method, a single electron beam is used to reproduce a color image, so color phosphor stripes are arranged perpendicularly to the scanning direction of the electron beam and have a certain relationship with the color phosphor stripes. A picture tube having a phosphor surface structure with an array of index phosphor stripes is used. The scanning position of the electron beam is detected using the index signal obtained from the index phosphor stripe as the electron beam scans, and this detected information is used to select the desired electron beam when scanning the desired color phosphor. By emitting a large amount of beam, an appropriate color image can be reproduced.

An example of the basic circuit configuration of the above-mentioned index type color reproducing apparatus is shown in No. 1- and will be explained in more detail.

In Fig. 1, reference numeral 1 designates an index tube, and its funnel part 2 is provided with a lighting window not coated with graphite or the like to let in the original input/output signal, and a photodiode 5 receives the original index signal, and the electric signal Convert to

Note that depending on the structure of the fluorescent surface, it is also possible to obtain an optical index signal from the front face plate side of the index tube.

The amplitude of the index signal converted into an electric signal is made constant by the limiter amplifier 4. The index force formula includes
The index phosphor arranged in the m triplet is 0.
In the case of a book, it is called n/... force type and can be roughly divided into two types.

A representative of the first type is the 1/1 force type, and a representative of the second type is the 6/2 force type. The difference between these types is
The issue is whether or not it is necessary to convert the frequency of the index signal obtained from the index tube using a frequency dividing circuit. That is, in the second type, the index signal frequency fi obtained from the index tube
It is necessary to divide the frequency by 1/rI and further multiply it by m to convert it to a triplet frequency fT suitable for index tube drive. Since a branching operation is inserted in the middle of this process, a start synchronization circuit is required to match the phase of the signal. What is needed is well known.

- Since the first type of power does not require a frequency dividing operation, there is also no need for a start synchronization circuit. Although there are differences between the first type and the second type as described above, the frequency of the signal that drives the index tube is the triplet frequency fT in both cases.

It is assumed that the output signal frequency of the limiter amplifier 4 in which the index signal amplitude in FIG. 1 is made constant is the triplet frequency fT.

The output signal of this limiter amplifier 4 is input to a multiplier 6 together with a color subcarrier signal (frequency; fsc ) applied to a terminal 5 . The output of the multiplier 6 is (fr+fsc
) and (, rT-fsc), but in filter 7, for example, (f7-1-fsc)
Next, the output signal of the filter 7 is applied to the carrier color signal (frequency;
fsc:l:,zf) and ) are both applied to the second multiplier 9. The output of multiplier 9 is (ft rod bf)
A signal with a frequency component of (17+2 fsc±xf) is obtained, but only the signal with a frequency component of (, fT-Hxf), which is suitable for driving the index tube, is selected by the filter 10. taken out. filter 10
The output signal is a color component signal for driving the index tube, and the index tube is driven by a composite signal obtained by adding a luminance component signal applied to the terminal 11 to this signal by an adder 12.

Now, compared to the shadow Yask method, the index force type has various characteristics due to being a single electron gun (...
Ru. For example, there is no need to adjust the safety.

Similarly, the white force adjustment required in the shadow mask force type using the Mikanshi gun is not necessary in principle because the index force type uses single electrons. However, the actual white chromaticity point of the index tube may vary due to variations in the coating width of each primary color phosphor on the index tube's fluorescent surface, and variations in luminous efficiency between manufacturing lots of phosphors. cannot be ignored (・For example, there is a variation of ±2000° with a color temperature centered around 9500°K, and the minimum discrimination unit (M
PCD), there is a variation of 40 MPCD, and this variation is at a level that cannot be tolerated by a normal shadow mask type color image reproduction device.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an index type color image reproducing device that absorbs variations in white chromaticity point caused by variations in phosphor coating width, phosphor emission efficiency, and the like.

[Summary of the invention]

In order to achieve the above object, the present invention adjusts the amplitude and phase of the index signal detected from the index tube, and then superimposes it on the index method video signal to drive the index tube.

[Embodiments of the invention]

An embodiment of the present invention is shown in FIG. 2 and will be described in detail. Second
In the figure, parts showing the same content as in FIG. 1 are given the same numbers. In FIG. 2, 16 is an amplitude adjustment circuit that changes the amplitude of the input signal and outputs it, and 14 is a phase adjustment circuit that changes the phase of the input signal and outputs it. Since the amplitude adjustment circuit 151C is supplied with the output of the limiter amplifier 4, a signal having a triplet frequency and whose amplitude and phase are adjusted to a predetermined magnitude is obtained as the output of the phase adjustment circuit 14.

Considering the case of reproducing white color on the INTEX tube surface, the amplitude of the carrier color signal applied to the terminal 8 is zero. Therefore, no signal appears at the output terminal of multiplier 9 either.

However, a constant signal matching the triplet frequency is obtained at the output terminal of the phase adjustment circuit 14. Therefore,
If the adder 15 adds the output signal of the phase adjustment circuit 14 to the output signal of the adder 12 to drive the index tube, then
Even though a white signal is being received, a certain hue corresponding to the above-mentioned certain signal is reproduced on the index tube. That is, the constant reproduced hue can be selected at any chromaticity point by adjusting the adjustment states of the amplitude adjustment circuit 15 and the phase adjustment circuit 14. Looking at this from the opposite perspective, it is possible to move the white chromaticity point, which varies due to variations in the phosphor coating width and luminous efficiency, to a desired chromaticity point in the index tube. , it is possible to absorb variations between sets.

In the second prisoner embodiment, adder 15? :: Adder 12 that adds the index color signal component and the luminance signal component.
Although the adder 15 is placed after the filter 10 and the adder 12, the adder 15 may be placed between the filter 10 and the adder 12, or may be placed in the luminance signal processing circuit before the adder 12.

In addition, although the output signal frequency of the limiter amplifier 4 has been explained as matching the triplet frequency, for example, in the case of the 6/'2 method, the frequency is changed to 2 after adjusting the amplitude and phase of the index signal frequency obtained by lighting. It may be configured such that the signal is multiplied by /6 and applied to the index tube for adjusting the white chromaticity point. Note that in the case where the output signal amplitude of the phase adjustment circuit 14 is always constant as described above.

It is conceivable that the amount of correction on the (x+y) chromaticity diagram differs depending on the brightness of the reproduced image. Therefore, as shown by the broken line in Figure 2, the gain of the amplitude adjustment circuit 13 is controlled so that it increases as the luminance level of the received signal increases, and a constant white point control amount is maintained no matter what brightness the white signal is received. It is also possible to obtain In addition, in the above configuration, when the control amount of the white chromaticity point is large, not only white but also red, green,
The effect also occurs when reproducing primary color signals such as blue. That is,
There is a possibility that the reproducible hue range on the chromaticity diagram determined by the phosphor used cannot be completely reproduced. In order to solve this problem, it is sufficient to add a circuit configuration that automatically controls the gain of the amplitude adjustment circuit 13 to be small when receiving a signal with a large color signal amplitude. It is easy to understand that the specific circuit configuration for this purpose can be constructed using only known circuits.

This makes it possible to reproduce the entire reproducible hue range determined by the phosphor while absorbing the white variation of the index tube.

〔Effect of the invention〕

As explained above, according to the present invention, variations in the white chromaticity point of the index tube caused by variations in the coating width of the phosphor, variations in luminous efficiency, etc. can be absorbed by a simple circuit configuration, and The white chromaticity point of the optical color image reproducing device can also be adjusted to a desired chromaticity point.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic circuit configuration of a conventional indexing force type color image reproducing device, and FIG. 2 is a block diagram showing an embodiment of the indexing force type color image reproducing device according to the present invention. . 1... Beam Intex tube 5... Photoelectric converter 4... Limit 7 amplifier 12... Index power type color signal and luminance signal adder 16... Amplitude adjustment circuit 14... Phase Adjustment circuit 15...adder

Claims (1)

[Claims] In an indexing color image reproducing device comprising an indexing color cathode ray tube, an indexing signal detector, an indexing color signal processing circuit, and a luminance signal processing circuit, the output of the indexing detector is supplied, and a control means for controlling the amplitude and phase thereof; , the output of the control means is q! 1. An index-type color image reproducing device, characterized in that it is provided with a compositing means for composing the output of the r signal processing circuit.