JPS6165686A - Index type color picture reproducing device - Google Patents

Abstract

PURPOSE:To current a dispersion in a white color chromaticity point of an index tube without changing a reproduced hue by changing a gain of a video signal amplification circuit by a correction signal, and time sharing a current value of an electron beam scanning R, G, B fluorescent materials so as to control the respective fluorescent materials. CONSTITUTION:According to an amplification circuit 40 of this example, by a pulse-shaped index signal fed to an input terminal 37, a collector current of a transistor 32 is made variable. In accordance with this, an impedance seen from an emitter of the transistor 32 is changed. Accordingly, a gain of a transistor 25 having a collector resistance of a fixed value can be change at a time sharing by the pulse-shaped index signal. Therefore, in an output terminal 27, a pulse-shaped constant signal having a frequency coinciding with a triplet frequency and set at a desired pulse width, amplitude and phase according to an adjusting condition of a wave form rectifying circuit 13, an amplitude adjusting circuit 14 and a phase adjusting circuit 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an index-type color image reproducing device, and more particularly to an index-type color image reproducing device that can adjust the white balance of an index tube without changing the reproduced hue. Regarding.

[Background of the invention]

Here, the principle of the index type color picture image reproducing apparatus will be briefly explained.

This method uses a single electron beam to scan the fluorescent surface of the index tube (wound W), thereby reproducing a color image. The fluorescent surface of the index tube has colored fluorophore stripes that emit red, green, and blue light, arranged perpendicularly to the scanning direction of the electron beam, and has a certain relationship with the color fluorophore stripes. It consists of an array of index phosphor stripes.

That is, the index type color image reproducing device detects the scanning position of the electron beam by using the index signal obtained from the index phosphor stripe as the electron beam scans, and uses the detected information signal to reproduce the desired image. A proper color image is reproduced by emitting a desired amount of electron beam when the color phosphor runs.

The above-mentioned index type color image reproduction device will be explained in more detail with reference to the drawings.

Figure 5 shows a block diagram of an example of a conventional index type color image reproducing device.

In the figure, 1 is an index tube, 2 is a face plate on the front of the Intex tube 1, 3 is a power converter, 4 is a limiter amplifier, 5 is an input terminal for a color subcarrier signal, 6 is a multiplier, 10 is a filter, 8 is an input terminal for a carrier color signal for the index method (hereinafter simply referred to as a carrier color signal), 9 is a multiplier of 2, and 11 is a signal for a luminance component for the index method (hereinafter simply referred to as a luminance component). 12 is an adder, and 16 is a video signal amplification circuit.

In Figure 5, a photoelectric conversion element 3 disposed on the front surface of the face plate 2 of the index tube 1 receives the original index signal from the index tube 1 and converts it into an index signal (electric signal).

Then, the fi width of the index signal converted into an electric signal is made constant by the limiter amplifier 4.

By the way, in the index method, when there is only one index phosphor arranged in an m triplet (a set of red, green, and blue phosphor stripes is called a triplet), it is called an n/m method.

There are two typical types of these. Type 21 is the 1/1 system, and type 2 is the 372 system.

The difference between these methods lies in whether or not it is necessary to convert the frequency of the index signal obtained from the index tube 1 via the photoelectric conversion element 3 using a frequency dividing circuit or the like.

That is, in the second method, it is necessary to divide the index signal frequency fi obtained from the index tube into 17n and further multiply it by m to convert it into a triplet frequency fT suitable for driving the index tube 1. Furthermore, it is well known that such a frequency division operation requires a start synchronization circuit to match the phases of the signals.

In the first method, there is no need for branching operations as described above.

For this reason, a start synchronization circuit or the like is not required. In this respect, the Sai1 method can be said to be superior.

Although there is a difference between the first method and the second method as described above, the frequency of the signal that drives the index tube 1 is the triplet frequency fT in both cases.

Here, the following description will be continued assuming that the frequency of the index signal whose amplitude is made constant and which is output from the limiter amplifier 4 is the triplet frequency fT.

The output signal of the limiter amplifier 4 is sent together with the color subcarrier signal (frequency fsc) applied to the terminal 5, ? 1 is input to the multiplier 6. As a result, a signal having frequency components of (, fT+fsc) and (fT-fsc) is obtained as the output of the first multiplier 6. The filter 7 extracts, for example, only the signal with the frequency component of (fT + fsc). The output signal of the filter 7 is then applied to a multiplier 9, together with a carrier color signal (frequency fsc±Δf) applied to a terminal 8. As a result, the output of the multiplier 9 of fang 2 is (fT±Δf) and (fT+2fsc±Δf
) is obtained.

The filter 10 extracts only the signal of the frequency component (fT±Δf) suitable for driving the index tube 1 from among the two frequency components.

In this way, the output signal from the filter 10 is only the color component signal necessary to drive the index tube, but this signal includes the luminance component signal applied to the terminal 11 at the adder 12. will be added. That is, the adder 12 creates a composite video signal.

This composite video signal is amplified by a video signal amplification circuit 16 and applied to the index tube 1.

As a result, the index tube is driven by the signal.

By the way, since the index method is a single electron gun,
When compared with the shadow mask method of the 3-electron gun, it has the following characteristics, for example.

First of all, there is no need for pie-elity adjustment. Furthermore, white balance adjustment, which is necessary in the three-electron gun shadow mask method, to adjust white balance distortion caused by differences in the drive characteristics of slave guns, is not necessary in principle with the single-electron gun index method.

However, due to reasons beyond the scope of the actual indexing method, there are variations in the white chromaticity point of each index tube.

This is due to variations in the exposure time during index tube manufacturing, which causes variations in the coating width of the red, green, and blue color changing light materials for each individual (index tube). This is due to variations in luminous efficiency between lofts.

This variation is, for example, around ±2000'K with a color temperature of 9300°K as the center, and is also based on the minimum discrimination unit (MPC), which indicates the amount of deviation from the color temperature locus of a perfect black body.
D) 1. It becomes aoMPcD Mudu. This is unacceptable (cannot be ignored) in normal color image reproduction equipment
That's about it.

Therefore, the following devices have been proposed as devices for absorbing the above-mentioned variations in the white chromaticity point of the index tube 1.

FIG. 6 is a block diagram showing another example of a conventional index type color image reproduction device.

In the figure, the same reference numerals as in Figure 1 indicate the same or equivalent items.

14 has a constant amplitude and a frequency of triplet frequency f
an amplitude adjustment circuit to which an index signal T is input;
15 is a phase adjustment circuit, and 18 is an adder.

In FIG. 16, a case will be described in which the amplitude of the carrier color signal applied to the input terminal 8 is zero and white color is reproduced on the index tube 1.

When the amplitude of the carrier color signal applied to the input terminal 8 is zero, the multiplier 9
, therefore, no color component signal is output from the filter 10.

However, as is clear from the above, the phase adjustment circuit 15 outputs a scheduled index signal that matches the triplet frequency fT.

Therefore, in this example, input is made from the input terminal 11, and the
The luminance component signal supplied via the index tube 2 and the output signal of the phase adjustment circuit 15 are added by an adder 18 to drive the index tube 1.

As a result, according to this example, it is possible to reproduce a certain hue on the index tube 1 even though a white signal is being received. That is, depending on the adjustment states of the amplitude adjustment circuit 14 and the phase adjustment circuit 15, the reproduced hue can be selected at any chromaticity point.

Therefore, in the device shown in Fig. 16, even if there is a variation in the white chromaticity point of the index tube 1, the white chromaticity point can be adjusted to any desired white chromaticity point, and the variation between tubes can be absorbed. You will be able to do that.

However, the conventional example shown in FIG. 16 has a drawback that, when a color signal is received, hue reproduction cannot be performed faithfully to the transmitting side. This will be explained below.

The correction shown in FIG. 16 can be said to be due to simple addition of the composite video signal, which is the output signal of the adder 12 in the drawing, and the index signal, which is the output signal from the phase adjustment circuit 15 in the drawing.

Now, let us consider the case where the index tube 1, which has a white chromaticity point that should be corrected in the edge direction, is corrected.

When the carrier color signal is input to the index tube 1 after this correction and color reproduction is performed, the output signal of the adder 12 is coswt (wx2πf, f is triplet frequency)
Also, the index signal (correction signal) from the phase adjustment circuit 15 is Acos (wt +φ) (A is the amplitude adjustment circuit 1
4 is the phase difference between the index signal set by the phase adjustment circuit 15 and the video signal)
It can be shown as

Therefore, the output signal V obtained by adding these two signals by the blade calculator 18. is expressed as the following equations (1) and (21).

Vow coswt-+4cos(wt+φ)(11v
o+m C08Wt + Acoswt@cosφ+A
sinwt@sinφ= (1+ Aco5φ)
coswt + As1nφ*sinwt output signal v
o will be obtained.

Now, since the correction signal is a signal in the edge direction, when the green primary color signal is received, the phase difference of the correction signal (index signal) becomes φ-0. However, the output signal V. &t
V6- (1+4)@coswt, which is a signal with an amplitude (1+A) times and a phase difference of zero. Therefore, in this case, it is possible to reproduce hues faithful to the transmitting side.

However, when reproducing other colors, the phase difference φ has a certain value. For this reason, as is clear from equation (2), the signal that drives the index tube 1 changes both S@ and phase, and the hue reproduced on the screen changes.

The conventional example shown in Figure 2 had the above-mentioned drawbacks.

[Purpose of the invention]

It is an object of the present invention to eliminate the drawbacks of the prior art described above, and to improve color reproduction by inputting color signals.

An index-type color image reproducing device that can suitably correct variations in the white chromaticity point of an index tube caused by variations in the coating width of the fluorine material, variations in the luminous efficiency, etc., without causing a hue change using a correction signal. Our goal is to provide the following.

[Summary of the invention]

The present invention is characterized in that an index tube, an index signal generation means obtained when the index tube is scanned with an electron beam, and an output of the index signal generation means, a color subcarrier signal, and a carrier color signal are respectively inputted. An index method color signal processing means for creating a color component signal necessary for driving the index tube, and an output of the index method color signal processing means and a luminance component signal are respectively inputted and the two signals are combined. and means for generating a composite video signal for driving the index tube, wherein a correction signal is created by adjusting at least the amplitude and phase of the index signal set to a triplet frequency as desired. A signal generating means and a video signal amplification circuit for controlling the level of the composite video signal in a time division manner according to the correction signal and applying the controlled composite video signal to the index tube are provided. There is pressure.

[Embodiments of the invention]

Figure 1 is a block diagram showing one embodiment of the present invention.

In the figure, the present invention will be explained below using the drawings.

Items that are the same or equivalent to Figure 5 and Figure 6 are designated by the same reference numerals. 13 is a waveform shaping circuit which converts an input signal into a pulse waveform of triplet frequency fT and whose pulse width can be varied; 40 is a 115L image signal amplification circuit.

In Figure 1, since the output index signal from the photoelectric conversion element 5 is supplied to the waveform shaping circuit 13, the output of the phase 11f11 circuit 15 has the triplet frequency and the desired pulse width, amplitude, and phase. A signal adjusted to the magnitude of is obtained. The signal is then supplied to the video signal amplification circuit 40 as a correction signal.

, 1?2 +U is a circuit diagram showing a specific example of the video signal amplification circuit 40.

In the figure, 25 is an output transistor for video signal amplification, and 32 is a transistor for variable impedance. Further, 28 is an input terminal to which the output composite video signal of the adder 12 shown in Figure 1 is applied, and 37 is an input terminal to which a correction signal for the phase adjustment circuit 15 of Figure 1 is applied, that is, a pulse-like index signal of triplet frequency. It is an input terminal that can be used easily.

21.22°33 indicates a power supply terminal.

Note that the output transistor 25 is connected to the power supply terminal 21 via a resistor 23 and grounded via a resistor 29. The collector of the transistor 25 is connected to the power supply terminal 22 via the resistor 24 and to the output terminal 27 via the capacitor 26 . Further, the emitter of the transistor 25 is grounded via a resistor 30 and connected to the emitter of a transistor 32 via a capacitor 31.

On the other hand, the collector of the transistor 52 is grounded, and the base thereof is connected to the power supply terminal 33 via a resistor 34, and is also grounded via a resistor 35.
6 to the input terminal 37.

As is clear from the configuration of the video signal amplification circuit 40 shown in FIG.
The collector current of the transistor 32 is varied by the pulsed index signal supplied to the transistor 7, and the impedance seen from the emitter of the transistor 32 changes accordingly.

That is, this means that the emitter resistance (referred to as the "elbow") of the output transistor 25 is variable.

Therefore, according to this embodiment, the gain Re/R of the transistor 25 having a constant value of the collector resistance (denoted as &)
Note that E can be varied in a time-division manner by the pulsed index signal. Here, when the amplitude of the carrier color signal applied to the input terminal 8 in FIG.
The case of reproducing white color on the surface will be explained.

When the amplitude of the electrically transmitted color signal applied to the input terminal 8 is zero, no color component signal is output from the multiplier 9, and hence from the filter 10, as described in FIG.

However, the phase adjustment circuit 15 outputs a scheduled pulsed index signal that matches the triplet frequency fT.

Therefore, the input terminal 2B of the video signal amplification circuit 40 in Figure 2 also receives the input terminal 11 in Figure 1, and the adder 1
A luminance component signal (a predetermined DC signal) supplied through the input terminal 2 is applied to the input terminal 37, while a predetermined pulsed index signal matching the triplet frequency is applied to the input terminal 37.

Therefore, the output terminal 271F in FIG. (The set pulse-like constant signal is obtained.

Therefore, if the index tube 1 is driven with this signal, the index tube 10 will be driven even though the white signal is being received.
A certain hue can be reproduced on the surface according to the certain signal.

That is, according to this embodiment, the waveform shaping circuit 13,
A beam current that generates the pulsed constant signal according to the adjustment state of the amplitude adjustment circuit 14 and the phase adjustment circuit 15, and scans the red (R), green (G), and blue (B) color fluorophores with this pulsed constant signal. Since f1 can be varied independently in a time-division manner, nine arbitrary color points can be selected from the constant hue reproduction f1.

This means that the white chromaticity point of the index tube 1, which varies due to variations in the color powder application width and luminous efficiency in the index tube, can be adjusted to any desired white chromaticity point. means. Therefore, according to this embodiment, variations between sets can be absorbed.

Furthermore, this will be explained using drawings.

Figures 3 and 3 are diagrams showing the fluorescent surface structure of the index tube 1 and the beam current that scans it.

Figure 3tal shows the fluorescent surface structure, and 41 in Figure 1al.
is an index phosphor, 42 is an aluminum metal back, 4
3 is face plaid glass, 44 is a guard band, and B, G, and B are color changing lights of red, green, and blue, respectively.

In addition, Figures 3(b) to lfl show the beam current scanning the fluorescent surface, and the horizontal axis shows time 1tl or position i-1 on the fluorescent surface, and the vertical axis shows the time 1tl or the position i-1 on the fluorescent surface. is the beam current value.

Now, in order to reproduce white, as shown in ps figure 1bl,
Assume that the index tube 1 has a light source amount ratio of 1:Q, 8:1 when scanning a G, B color band light body with a constant beam current. However, H., G.
It is assumed that the optimum white chromaticity point is obtained at a light emission ratio of 1:1:1 of the B color band light body.

In this case, the white color being reproduced is deviated from the optimal white chromaticity point.

At this time, using the electrical protection of this embodiment, the input terminal 3 of Fig.
the pulse width of the pulsed index signal supplied to 7;
By adjusting the beam width and phase and increasing the gain of the output transistor 25 only during the period when the single beam scans the G phosphor, the beam current value can be increased to 5 as shown in Figure 3. It can only be destroyed during this period.

In other words, the key is to adjust the ratio of the starting elements of JG%B to +:tH1 that provides the optimum white chromaticity point.
In addition to being able to reproduce a beautiful white color on the screen,
It is also possible to eliminate variations in white chromaticity point at the same time.

Here, in the actual index tube 1, the imbalance in the ratio of the emission sources of the color changing light bodies of RlG and B is, for example, 1:
A case like α8:06 can also be considered. Next, a correction method in such a case will be explained using Fig. 4 and Fig. 3 (d).

Figure 4 is a block diagram showing a second embodiment of the present invention. In the same figure, the same or equivalent parts as those in Figure 1 are indicated by the same reference numerals.

Further, in Fig. 4, 13°, 14°, and 15゛ are respectively the same waveform shaping circuit, amplitude adjustment circuit, and phase adjustment circuit as 13, 14, and 15 in Fig. 1, and 17 is an adder.

The difference between this 2nd embodiment and the above 1st embodiment is that
A new set of circuits consisting of a waveform shaping circuit, a photo adjustment circuit, and a phase adjustment circuit is installed.The outputs of these two series of circuits are added together using an adder 17 to create a correction signal. This is because the signal is supplied to the video signal amplification circuit 40.

Therefore, according to the second embodiment, as can be easily understood from the explanation of the embodiment shown in FIG. Since the value of 1:0.8:o and 6 can be adjusted to be large, the imbalance of 1:0.8:o and 6 described above can be resolved.

In other words, by varying the value of the beam current as shown in Figure 3 (dl), it is possible to set the white chromaticity point to an optimal state, and also to eliminate variations between tubes. Become.

In addition, the above 5I? In the embodiments of Figures 1 and 4,
Although the signal is directly obtained from the photoelectric conversion element 3 which is the input of the waveform shaping circuit, it is clear that the output signal of the limiter amplifier 4 may also be used.

Also, 3rd figure 1c1. (In di, the pulse width of the constant signal corresponding to the correction signal is set to exactly the width corresponding to the period during which the color changing light body is scanned, but it is not necessarily limited to this.

In other words, this variation in pulse width is acceptable as long as it is within the length range from the left end of the guard band located to the left of a certain color-changing light body to the right end of the guard band located to the right of that fluorescent body. It is something that will be done.

An example of the beam current that scans the index tube 1 when the white-balanced IJfi'7'-1 color signal is input during white reproduction as described above is shown in Figure 3.
(e) and b: are shown, respectively. Figure 23 tel is the same figure 1c
It corresponds to l, and 3rd figure B) corresponds to +dl in the same figure.

As is clear from this figure (Figure 3), in this embodiment, even if a color signal is input during the scanning period of the color changing light body with a large beam current to maintain white balance, the beam It changes the value of current.

Therefore, according to this embodiment, it is possible to reproduce hues faithful to the transmitting side while absorbing white variations in the index tube 1.

Furthermore, in the present embodiment, the correction signal applied to the input terminal 37 in FIG. This is because even with a sine wave signal, the gain of the output transistor 25 can be controlled in substantially the same way as with a pulse signal, so the above effect is determined by sufficient realization.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the gain of the video signal amplification circuit is changed by the correction signal, and R
The current value of the electron beam scanning the , G, and B color phosphors can be controlled in a time-division manner for each phosphor, and the white chromaticity point of the index tube is adjusted to the desired chromaticity point. This has the effect of being able to correct variations in the white chromaticity point of the index tube caused by variations in phosphor stripe width, variations in luminous efficiency, etc., without changing the reproduced hue. .

[Brief explanation of drawings]

Figure 1 shows an embodiment of the present invention. Figure 2 shows a block diagram of an embodiment of the present invention.
? A circuit diagram showing a specific example of the video signal amplification circuit shown in Fig. 1, Figs. Fig. 5 is a block diagram showing an example of a conventional index-type color reproducing device, and Fig. 6 is a block diagram showing another conventional example. 1... Index tube, 3... Photoelectric conversion element, 4.
...Limiter amplifier, 6,9...Multiplier, 7.10.
... Filter, 12.17 ... Adder, 14.14'
... Amplitude adjustment circuit, +5.15' ... Phase adjustment circuit, 40 ... Video signal amplification circuit.

Claims (2)

[Claims] (1) An index tube, an index signal generation means obtained when the index tube is scanned with an electron beam, and an output of the index signal generation means, a color subcarrier signal, and a carrier color signal for the index method are inputted, respectively. An indexing method color signal processing means for creating a color component signal necessary for driving the indexing tube, and inputting the output of the indexing method color signal processing means and the indexing method luminance component signal respectively, and generating both signals. and a means for generating a composite video signal for driving the index tube, in which a correction signal is created by adjusting at least the amplitude and phase of the triplet frequency index signal as desired. Comprising a correction signal generating means, and a video signal amplification circuit for time-divisionally controlling the level of the composite video signal according to the compensation signal and applying the controlled composite video signal to the index tube. An index method color image reproducing device characterized by: (2) The index method color image reproducing apparatus according to claim 1, characterized in that two correction signal generating means are provided in parallel, and the outputs thereof are added to form the correction signal. .