JPS6047790B2 - signal display circuit - Google Patents

Description

[Detailed description of the invention] The present invention relates to a signal display circuit.

In general, if the main unit of a chime or intercom is installed in a place far away from the television receiver and you are watching the television receiver (for example, if the main unit is installed in the kitchen on the first floor and the main unit is installed in the kitchen on the second floor, (such as when watching a television receiver) or when watching a television receiver with the volume set relatively high, the call tone of the parent device (for example, a ping-pong sound) It often happens that you cannot hear the sound.

At that time, if the visitor signal is displayed just by looking at the display screen of the television receiver, it is very convenient to know that the visitor is a visitor even if one cannot hear a chime or other call sound. It is therefore an object of the invention to provide a highly convenient signal display circuit.

An embodiment of this invention will be described below.

FIG. 1 is a block diagram showing the connection relationship between the visitor signal display circuit of this embodiment, a television receiver, and a chime (the principle is the same for an intercom). 1 and 2 are the master and slave devices of the chime, respectively. , 3 is a television receiver, 4 is a visitor signal display circuit, 5 is a chassis, 6 is a connection line between the channels 1 and 2 and the television receiver 3, and 7 is a connection line between the chassis 5 and the visitor signal display circuit 4. , 8 is a connection line between the master device 1 and the pre-device 2. The one shown in FIG. 1 will be briefly explained. Now, when the switch of the slave unit 2 of the chain is pressed, a potential difference is generated between the two wires of the connection line 8 with the master unit 1. This signal is input to the television receiver 3 via a connection line 6. The connection line 7 transmits the power supply, ground line, vertical oscillation signal, horizontal oscillation signal, and blanking pulse from the chassis 5 to the visitor signal display circuit 4, and also transmits the visitor display signal from the visitor signal display circuit 4 to the chassis 5, and further connects The signal from line 6 is transmitted to visitor signal display circuit 4. When the signals from the teams 1 and 2 are added to the visitor signal display circuit 4, the visitor display signal becomes a blinking signal for several seconds and is added to the G-Y output signal of the chassis 5. This allows a rectangular display to be displayed on a part of the display surface of the television receiver 3. Note that although the color of the rectangular portion was recorded this time, other colors such as red or blue can be produced in the same way. Figure 2 shows teams 1 and 2 and a television receiver. 3 is a specific connection diagram regarding the connection relationship of No. 3, that is, the connection line 6 of FIG. 1. FIG.

9 is an earphone terminal; 10 and 11 are connecting wires and plugs for connecting the two wires of channels 1 and 2 to the earphone terminal 9 of the television receiver 3; 12 is an earphone transformer;
3 is a separate transformer.

The reason why the earphone terminal 9 was used to connect the channels 1 and 2 and the television receiver 3 is because the earphone terminal 9 is currently of a two-hole type, so either one can be used without the need for a dedicated terminal. This is because it is very superior in terms of cost and ease of connection. Separate transformer 1
3 is for separation because the chassis 5 is not cold. Although it is possible to omit the separate transformer 6 by using the separate transformer 13 as the earphone transformer 12 of the chassis 5, it is difficult to completely eliminate malfunctions caused by audio signals. The structure is as follows. ) Next, FIG. 3 shows how signals are transmitted when the chains 1 and 2 are operated.

In Figure 3, the switch of slave device 2 is pressed at t=t1, and t=T
In the period t1 x t<T2, a potential difference occurs between the two wires of channels 1 and 2 as shown in FIG. 3A, and when the wires are connected to the earphone terminal 9. Since it becomes a reactance load of the separate transformer 13, it becomes a waveform that is differentiated as shown in FIG. 3B and mixed with the audio signal. Therefore, in order to eliminate malfunctions caused by audio signals, the next stage circuit selects the level and removes the audio signals. Fig. 4 is an internal block diagram of the visitor signal display circuit 4. 4 can be roughly divided into three blocks.

4a is a rectangular display circuit that always displays a rectangular display on a part of the display surface of the television receiver 3; 4b is a circuit that outputs the output of the rectangular display circuit 4a only for a certain period of time when triggered by a pulse from the separate transformer 13; The controlling time control circuit 4c is a blinking control circuit controlling the rectangular display to blink.

FIG. 5 is a specific circuit diagram of the visitor signal display circuit 4.

In FIG. 5, the rectangular display circuit 4a is a first level detection circuit that detects a period in which the vertical oscillation signal is between the first and second levels and generates a first pulse train having a pulse width of that period. 1, and a second level detection circuit that detects a period in which the horizontal oscillation signal is between the third and fourth levels and generates a second pulse train having a pulse width of that period.
and a pulse removal circuit that removes the first and second pulses generated during the vertical and horizontal retrace periods, respectively, from the first and second pulse trains generated by the first and second level detection circuits 1 and 1, respectively. ■This pulse removal circuit■
a product circuit (2) which calculates the product of the first and second pulse trains from which the first and second pulses have been removed and adds the product to the color difference signal output of the television receiver; By adjusting the third and fourth levels, a colored rectangular display can be displayed at any position on the display surface of the television receiver. To explain in more detail, in FIG. 5, T1 is a power supply terminal, T2 is a vertical oscillation signal input terminal, T3 is a ground terminal, T4 is a blanking pulse input terminal, T5 is a horizontal oscillation signal input terminal, and T6
has an output terminal. The operation of this rectangular display circuit will be explained with reference to FIG. The vertical oscillation signal input to the base of transistor Q1 is the emitter follower output (sixth
It is added to the emitters of a pair of transistors Q2 and Q3 for vertical oscillation signal level detection as shown by the solid line a) in FIG. If the base potential of transistor Q2 (solid line b in FIG. 6A) is made larger than that of transistor Q3 (solid line c in FIG. 6A) by adjusting variable resistors Rl and R2,
The respective collector outputs are as shown in FIG. 6B and C. When these signals are input to the base and emitter of vertical range setting transistor Q4, respectively, the output of its collector becomes as shown in FIG. 6D. 6th
As can be seen from the waveform in Figure D, since a positive pulse is generated in principle during the vertical retrace period, the switching operation of transistor Q5 is performed using the vertical blanking pulse (Fig. 6 E), and the above-mentioned vertical retrace period is A positive pulse is prevented from coming out of transistor Q4 (FIG. 6F). The emitter follower transistor Q6, the pair of transistors Q7 and Q8 for horizontal oscillation signal level detection, the horizontal range setting transistor Q9, and the variable resistors R3 and R4 are elements that contribute to horizontal oscillation signal processing, and the transistor Q1 described above ,Q
2, Q3, Q4 and variable resistors Rl, R2. The collector output of transistor Q9 becomes as shown in FIG. 6G due to the horizontal blanking pulse applied to blanking pulse input terminal 4. This sixth
The signals shown in FIGS. F and G are inputted to the respective bases of series-connected transistors Ql2 and Ql3 via emitter followers (transistors QlO and Qll). In this circuit of transistors Ql2 and Ql3, the collector output of transistor Ql3 exhibits NAND gate operation with respect to the respective base input signals. Therefore, the collector output of the next stage transistor Ql4 with inverted gate operation becomes as shown in FIG.
5 and Ql6, it is added to the color difference signal output of the television receiver from the output terminal T6. As a result, as can be seen from FIG. 6, the difference in base potential of transistors Q2 and Q3 is proportional to the size of the rectangular display in the vertical deflection direction, and the difference in base potential of transistors Q7 and Q8 is proportional to the size of the rectangular display in the horizontal deflection direction. The variable resistance Rl is proportional to the size of the rectangular display of
, R2, R3, and R4, a rectangular display of any size can be displayed at any position on the display surface of the television receiver. The situation is shown in FIG. 14 is the display surface of the television receiver, 15 is a rectangular display section, 16 is a vertical oscillation signal, 17 is a horizontal oscillation signal, 18, 19, 20 and 21 are transistors Q2, Q3, Q7, Q, respectively.
8 base potential.

Note that the color of the rectangular display section 15 depends on which color difference signal output
The problem is how to connect the output terminal T6 shown in the figure. For example, for color recording, it is sufficient to add it to the G-Y color difference signal output.

Further, in FIG. 6, the collectors of transistors Q4 and Q9 are commonly connected, but according to experiments, no mutual interference of signals occurred. The time control circuit 4b utilizes the charging and discharging of a capacitor and a resistor, and
At the moment when the switch is pressed, the output of the separate transformer 13 includes the pulses from the channels 1 and 2 and the audio signal due to the signals applied from the terminals T7 and T8. It is designed to be in the on state, completely eliminating malfunctions caused by audio signals.

This pulse turns on the transistor Ql7, and the charge stored in the capacitor C1 is discharged at once through the diode D1 and the transistor Ql7.
Transistor Ql8 is turned on. After that, when the pulse disappears and the transistor 17 turns off, the capacitor C1 is slowly charged through the semi-fixed resistor R5 until the base potential of the transistor Ql8 is lower than the emitter potential by the benos-emitter voltage ■BE. Ql8 remains on. Transistor Ql
9 is normally on, and if you press the switch on slave unit 2,
T with the time constant due to capacitor C1 and semi-fixed resistor R5
It is connected to the base of transistor Ql5 so that it is in an off state for a second and outputs a display output. For example, R5
= 100KΩ, C1 = 47μF, and a blinking time of about 1 circle 2 is provided. This operating state is shown in FIG. 8A is the output of channels 1 and 2, FIG. 8B is the output of the separate transformer 13, FIG. 8C is the base input of the transistor Ql7, FIG. 8D is the base input of the transistor Ql8,
8E is the collector output of transistor Ql8, and FIG. 8F is the base input of transistor Ql9. The blinking control circuit 4c is composed of a normal astable multivibrator, and the collector of the transistor Q2O is connected to the base of the transistor 15, and the transistor Q2O is turned on at predetermined time intervals.
is cycling on and off.

In a specific example, the values of capacitors C2 and C3: resistor R6 and semi-fixed resistor R7 are respectively C2=C3=10μF, R
By setting 6=BKΩ and R7=100K, the rectangular display lighting time was set to about 0 seconds, and the light-off time was made variable up to about 0.7 seconds. As a result of this configuration, the following effects were obtained.

Since the visitor signal flashes for a certain period of time on the display screen 14 of the television receiver 3, it is convenient to know that the visitor is a visitor even if the sound of chimes 1 and 2 cannot be heard.

(B) Connection with any television receiver 3 is possible. (C) Connection between the cameras 1 and 2 and the television receiver 3 is made via the earphone terminal 9. And it's very easy to do.

(D) The circuit configuration is simple, the number of parts is small, and it does not take up much space for installation.

(E) Displays such as visitor signals can be projected at any position on the display screen (CRT screen), so they can be displayed without interfering with normal images, and the display can be It can also be projected in an eye-catching position.

As described above, the signal display circuit of the present invention is capable of transmitting an external signal such as visitor information to an earphone terminal in a device that displays information such as visitor information on the cathode ray tube screen of a television receiver to notify that fact. In addition to making the above display a rectangular colored display, the colored display can be moved to any position on the cathode ray tube screen, and has an external signal input terminal. Since the earphone terminal is used as the earphone terminal, there is no need to newly provide a dedicated terminal.In addition, in this case, most of the current television receivers have a two-hole earphone terminal, so you can use one of the earphone terminals. There is almost no problem in practical use, and it is extremely advantageous in terms of cost and ease of connection, and the position of the colored display can be moved to any position, so it does not interfere with normal images. It is also possible to display the colored display at a position that will most catch the viewer's attention.

[Brief explanation of the drawing]

Fig. 1 is a connection configuration diagram of a visitor signal display circuit according to an embodiment of the present invention, Fig. 2 is a connection diagram between a chime and a television receiver, and Fig. 3 is an explanatory diagram of the operation of the separate transformer shown in Fig. 2. , FIG. 4 is an internal block diagram of a visitor signal display circuit according to an embodiment of the present invention, FIG. 5 is a specific circuit diagram thereof, and FIGS. 6 and 7 are signal waveform diagrams and operations of each part of the rectangular display circuit, respectively. The explanatory diagram, FIG. 8, is a signal waveform diagram of each part of the time control circuit. 1... Master device of the channel, 2... Child device of the channel, 3... Television receiver, 4...
... Visitor signal display circuit, 4a ... Rectangular display circuit, 4b ... Time control circuit, 4c ... Flashing control circuit, 9 ... Earphone terminal, 13・・・・・・
...Separate transformer, I...First level detection circuit, ■...Second level detection circuit, ■...
...Pulse removal circuit, ■...Product circuit, T
2...Vertical oscillation signal input terminal, T4...Blanking pulse input terminal, T5...Horizontal oscillation signal input terminal, T6...Output terminal, Q1 to Ql6
...Transistor, R1-R4...Variable resistor.

Claims (1)

[Claims] 1. A first level detection circuit that detects a period in which a vertical oscillation signal is between first and second levels and generates a first pulse train having a pulse width of that period; a second level detection circuit that detects a period in which the signal is between third and fourth levels and generates a second pulse train having a pulse width of that period; and the first and second level detection circuits. a pulse removal circuit that removes the first and second pulses generated during the vertical and horizontal retrace periods from the first and second pulse trains generated, respectively; and the pulse removal circuit removes the first and second pulses. a product circuit that calculates the product of the first and second pulse trains; an earphone terminal of the television receiver into which an external signal such as visitor information is input; and a product circuit that multiplies the first and second pulse trains; a time control circuit that adds the output of the product circuit to the color difference signal output of the television receiver; and a blinking control circuit that continues the output of the product circuit that is added to the color difference signal output during the predetermined time, the first , second, third
and a fourth level, whereby a colored rectangular display can be displayed at any position on the display surface of the television receiver. 2 The first level detection circuit connects both collectors of a pair of differentially connected vertical oscillation signal level detection transistors to the base and emitter of a vertical range setting transistor, respectively, and detects the level of the pair of vertical oscillation signals. The vertical oscillation signal is applied to a common emitter of the vertical range setting transistor, and the first and second levels are applied to the bases, respectively, and the first pulse train is extracted from the collector of the vertical range setting transistor. The signal display circuit according to scope 1. 3. The second level detection circuit connects both collectors of a pair of differentially connected horizontal oscillation signal level detection transistors to the base and emitter of a horizontal range setting transistor, respectively, and connects the horizontal oscillation signal level detection transistor to a common emitter of the transistors. The signal display according to claim 1, wherein an oscillation signal is applied and the third and fourth levels are applied to the bases, respectively, and the second pulse train is taken out from the collector of the horizontal range setting transistor. circuit.