JPS6133310B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides accurate and accurate adjustment of television receivers.
In addition, the present invention provides an apparatus in which a pattern generation circuit is incorporated in a television receiver to facilitate the invention.

In color television receivers, accurate adjustment of white balance and convergence is necessary for correct image reproduction, and conventionally, a pattern generator is provided as an independent device to facilitate such adjustment. During adjustment, this pattern generator was externally connected to the television receiver. However, such conventional devices have the inconvenience of having to carry the pattern generator and connect it to the television receiver each time adjustments are made, and furthermore, these pattern generators do not have their own synchronization generation circuit. The synchronization period is often different from that of television broadcasting, and this has the disadvantage that accurate synchronization cannot be achieved when adjusting the television receiver, resulting in incomplete adjustment. It was hot.

Therefore, it is an object of the present invention to provide a device that eliminates all of the conventional drawbacks.

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

First, Figure 1 shows its basic configuration, where 1 is an antenna, 2 is a television receiver circuit,
3 is a pattern generation circuit, and 4 is a cathode ray tube. The television receiver circuit 2 includes a tuner 5, a VIF amplifier circuit 6, a video detection circuit 7, a video amplifier circuit 8, a synchronization separation circuit 9, a vertical deflection circuit 10, and a horizontal deflection circuit 1.
1, which are similar to those in ordinary television receivers. These television receiver circuits 2 output vertical pulses to a terminal 12 and horizontal pulses to a terminal 13, respectively.

On the other hand, the pattern generation circuit 3 includes a terminal 14 for receiving vertical pulses and a terminal 15 for receiving horizontal pulses, and controls a gated oscillator 16 by the horizontal pulses received at the terminal 15 to generate horizontal pulses within the horizontal scanning period. make it oscillate at a frequency that is sufficiently higher than the frequency of (15.75KHz). The oscillation output is sent to a horizontal frequency divider 17 consisting of a counter, etc.
Here, the oscillation output is frequency-divided and the frequency-divided output is generated at regular intervals and at least once during one horizontal period, preferably several to ten times. This frequency-divided output determines the individual size and horizontal position of the dot pattern generated on the cathode ray tube 4. Specifically, since one horizontal scanning period excluding the horizontal blanking period is approximately 50 μsec, for example, when generating 15 dot patterns in the horizontal direction as shown in Fig. 4, one horizontal scanning period is required. It is sufficient to generate a frequency-divided output every 1/15 of the period, that is, approximately every 3.3 μsec, and the frequency division of the horizontal frequency divider 17 to generate this frequency-divided output is 1/16. This will reduce the oscillation frequency of gated oscillator 16 to approximately 4.8MHz.
Just leave it as . Further, the horizontal width of each dot pattern is determined by the pulse width of the output from the horizontal frequency divider 17, and in the above case, approximately 2 bits of the oscillation output of the gated oscillator 16 is appropriate.

Furthermore, in the pattern generation circuit 3, the terminal 1
5 is added to a vertical frequency divider 18 composed of a counter or the like, which divides the horizontal pulse and divides the frequency of the horizontal pulse at regular intervals and at least several times during one vertical scanning period, preferably several times to more than 10 times. , generates a divided output. This divided output determines the individual size and vertical position of the dot pattern generated on the cathode ray tube 4. Specifically, since one vertical scanning period excluding the vertical blanking period is approximately 15.6 msec, for example, if 15 dot patterns are to be generated in the vertical direction as shown in Fig. 4, one vertical scanning period is approximately 15.6 msec. The period of one-fifteenth of the period, i.e. approx.
It is sufficient to generate a frequency-divided output every 1 msec, and in order to generate such a frequency-divided output, the frequency division ratio of the vertical frequency divider 18 may be set to 1/15. Further, the vertical width of each dot pattern is determined by the pulse width of the frequency-divided output taken out from the vertical frequency divider 18, and in the above case, the horizontal scanning line 2
Duty level is appropriate.

Then, by adding the frequency division output of the horizontal frequency divider 17 and the frequency division output of the vertical frequency divider 18 to the AND gate 19 to create a logical product, it is suitable to display a dot pattern as shown in FIG. A pattern signal can be created, which is sent to the television receiver circuit 2 via the buffer amplifier 20 and terminals 21 and 22.
By adding it to the video amplification circuit 8 inside, it is possible to display a dot pattern as shown in Fig. 4 on the cathode ray tube 4, and using this, accurate adjustment of white balance and convergence can be performed extremely easily. . In this case, the pattern generation circuit 3
By incorporating the television receiver circuit 2 and cathode ray tube 4 into the same television receiver cabinet, the pattern can be displayed with the simple operation of flipping a switch during adjustment, and a separate pattern generator can be used. Since the inconvenience of external connections can be eliminated, work efficiency can be greatly improved. Furthermore, a particular advantage of this device is that all the control synchronization signals for pattern generation are taken out from the television receiver circuit 2, so that the pattern signal is in the correct synchronization state and is completely synchronized with the synchronization signal of the television broadcast signal. By using such a pattern signal, it is possible to make a completely correct adjustment.

Next, a more specific configuration of such an apparatus is shown in FIGS. 2 and 3. Figure 2 shows the pattern generation circuit 3.
FIG. 3 is a specific circuit diagram of a portion connected to the video amplification circuit 8, and in each figure, parts corresponding to those in FIG. 1 are given the same reference numerals.

In FIG. 2, numeral 23 denotes a coil for picking up horizontal pulses from the television receiver circuit 2, and this coil is installed near the flyback transformer of the horizontal deflection circuit 11 to extract the flyback pulses. 24 is a waveform shaping circuit for shaping the horizontal pulse; 25 is a capacitor for resonance with the horizontal pulse; 26, 27, 2
8 is an amplification transistor, transistor 2
7 has an amplitude limiting effect.

Further, 29 is a coil for picking up vertical pulses from the vertical deflection circuit 10, and this coil is attached near a vertical output transformer or the like of the vertical deflection circuit 10 to extract the vertical pulses. In this case, since the vertical pulse is taken out with either positive polarity or negative polarity, the polarity is switched by the switch 30 and taken out with positive polarity. This vertical pulse is also waveform-shaped by a waveform-shaping circuit 31 similar to the waveform-shaping circuit 24.

The gated oscillator 16 is composed of a known unstable multivibrator, and a horizontal frequency divider 17
is a 4-pit binary counter 32 and an AND gate 3
Consists of 3. Furthermore, the vertical frequency divider 18 is composed of a flip-flop 34 which divides the frequency by half in advance, a 4-bit binary counter 35, and an AND gate 36.

Here, the horizontal position and size of the pattern can be changed by changing the oscillation frequency of the gated oscillator 16 or the frequency division ratio and output bit number of the horizontal frequency divider 17. By changing the circumferential ratio or the number of output bits, the vertical position and size of the pattern can be changed.

Furthermore, in FIG. 3, the pattern signal generated by the pattern generation circuit 3 as described above is transmitted to the video amplification transistors 37 and 3 in the video amplification circuit 2.
Supply to 38 bases out of 8,39. In this case, in a normal television receiver, the emitter of the transistor 37 and the base of the transistor 38 are directly connected as shown by the broken line, and the test point terminal TP is provided here, so this is used as the terminal 22. Terminal 2 on the output side of the buffer amplifier circuit 20 so as to supply a pattern signal here.
This can be accomplished most easily by connecting 1.

Further, it would be even better if a changeover switch 40 is provided here.

In addition, 41 is a service switch that cuts off the power to the oscillation transistor 42 of the vertical deflection circuit 10 when displaying only horizontal lines, and also cuts off the power to the oscillation transistor 42 of the vertical deflection circuit 10.
This prevents the addition of video signals to the

Incidentally, such a portion of the pattern generating circuit 3 may be made into an integrated circuit element and may be detachably attached to the television receiver circuit 2 in the cabinet of the television receiver.

Note that the specific circuit configuration for carrying out the present invention is not limited to that of the above embodiment,
A wide variety of materials can be used as long as they provide similar effects.

As detailed above, the pattern generator for a television receiver according to the present invention includes a gated oscillator that is controlled by a horizontal pulse extracted from a television receiver circuit and oscillates at a frequency higher than the frequency of the horizontal pulse. , divide the oscillation output of this gated oscillator at regular intervals, and
A horizontal frequency divider that generates one or more outputs during one horizontal scanning period, and a horizontal frequency divider that circularly divides the horizontal pulse taken from the television receiver circuit and generates outputs at regular intervals and one or more times during one vertical scanning period. and a vertical frequency divider, and is characterized in that a logical product signal of the output of the horizontal frequency divider and the output of the vertical frequency divider is supplied to a cathode ray tube of a television receiver to project a pattern. Therefore, it is possible to adjust the television receiver extremely easily and accurately.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a pattern generator for a television receiver according to an embodiment of the present invention;
2 and 3 are specific circuit diagrams of the main parts of the device, and FIG. 4 is a front view of a pattern display mode in the device. 2...Television receiver circuit, 3...Pattern generation circuit, 4...Cathode ray tube, 8...Video amplification circuit, 10...
Vertical deflection circuit, 11...Horizontal deflection circuit, 16...Gated oscillator, 17...Horizontal frequency divider, 18...Vertical frequency divider, 19...AND gate, 20...Buffer amplifier circuit.

Claims (1)

[Claims] 1 A horizontal pulse and a vertical pulse are extracted from a horizontal deflection circuit and a vertical deflection circuit in a television receiver circuit using a pickup coil, and oscillation is performed at a frequency higher than that of the horizontal pulse under the control of the horizontal pulse. a horizontal frequency divider that divides the oscillation output of the gated oscillator and generates an output at regular intervals and at least once during one horizontal scanning period; a vertical frequency divider that divides the frequency of the horizontal pulse and generates an output at regular intervals and at least once during one vertical scanning period, the output of the horizontal frequency divider and the output of the vertical frequency divider. 1. A pattern generating device for a television receiver, characterized in that a pattern is projected by supplying an AND signal of the above-mentioned signal to a cathode ray tube of the television receiver.