JP2949559B2 - Cathode ray tube display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube display device having an energy saving function for reducing power consumption when the computer is not used, and to an improvement in the life of a heater electrode of the cathode ray tube during the energy saving operation.

[0002]

2. Description of the Related Art When a computer is not used and an energy saving function is in operation, a combination of a synchronizing signal and power consumption necessary for the cathode ray tube display device to perform an energy saving operation are determined by a VESA (Video Electronics Standard).
(Association) defines the guidelines as shown in (Table 1). This (Table 1) shows the relationship between the synchronization signal and each power consumption in the energy saving operation state defined by VESA.

[0003]

[Table 1]

According to this, assuming that the power consumption in the ON STATE mode (normal operation state) is 100%, the power consumption when the computer is not used is 80% or less in the STAND BY mode,
It is 30W or less in PEND mode and 8W or less in OFF STATE mode. In particular, in OFFSTATE mode, the minimum circuit that can recognize the synchronization signal must be operating,
This is different from normal power OFF. Further, the time required to return to the ONSTATE mode (normal operation state) with the start of use of the computer needs to be reduced to such an extent that the user does not feel "wait". In the SUSPEND mode, the B voltage supplied to each circuit is turned off to reduce power consumption, and the heater electrode of the cathode ray tube is set to the preheat state to shorten the return time to the ON STATE mode (normal operation state). There is a need to.

FIG. 3 shows a circuit diagram of a conventional cathode ray tube display device. 3, reference numeral 1 denotes a video output circuit 7.
DC voltage stabilization circuit with output voltage ON / OFF function (hereinafter referred to as B voltage stabilization circuit 1) for supplying B voltage
Is an output voltage ON / OFF for supplying a B voltage of another circuit (here, the vertical output circuit 8) lower than the B voltage.
DC voltage stabilizing circuit with function (hereinafter referred to as B voltage stabilizing circuit 2), 3 is a DC voltage stabilizing circuit with output voltage ON / OFF function for supplying a heater constant voltage and a preheating voltage (hereinafter, heater constant voltage stabilizing circuit) Circuit 3), 5
Is a switching power supply transformer, 6 is a power supply rectification smoothing circuit,
9 is a transistor for switching the output voltage of the heater constant voltage stabilization circuit 3 to the heater electrode preheating voltage,
Reference numerals 10, 11, and 12 denote output voltage ON / OFF switching transistors of the DC voltage stabilizing circuits 3, 2, and 1, reference numeral 13 denotes a cathode electrode, reference numeral 14 denotes a heater electrode, and reference numeral 15 denotes a cathode ray tube.

In this conventional example, the B voltage of another circuit lower than the B voltage of the video output circuit 7 is used as the B voltage of the vertical output circuit 8, and the STAND BY signal shown in (Table 1) is used for streamlining the circuit.
Mode and SUSPEND mode function as the same mode.

Here, (Table 2) shows the operation of the switching transistor of the output of the DC voltage stabilizing circuit in each mode shown in (Table 1), the B voltage of the video output circuit and the vertical output circuit, the heater voltage and 4 shows the power consumption of a cathode ray tube display device.

[0008]

[Table 2]

FIG. 4 shows changes in the cathode electrode 13 and the heater electrode 14 in each mode shown in (Table 2). FIG. 4A shows the case of the conventional example shown in FIG. FIG. 1C shows the case of the holding or variable voltage type, and FIG. 1C shows the case of the embodiment of FIG. 1 of the present invention.

First, in the normal operation state (ON STATE mode), as shown in Table 2 and the conventional example of FIG. 4A, the transistors 9 to 12 are OFF, and the respective B voltage stabilizing circuits 1 and 2 are turned off. 2 is turned on, and as shown in (Table 2),
Consumes 100W of power. When entering the SUSPEND mode, the transistors 11 and 12 are turned on and the video output circuit 7 and
The output B voltages of the B voltage stabilization circuits 1 and 2 that supply the B voltage of the vertical output circuit 8 are turned off, and the transistor 9 is turned on to lower the output voltage of the heater constant voltage stabilization circuit 3 from the rated voltage. The heater electrode 14 is in the preheat state, and the power consumption is reduced to about 10 W as shown in (Table 2). In OFF STATE mode, the transistor
10 is turned on, all the transistors are on, the output voltage of the heater constant voltage stabilizing circuit 3 is also turned off, and the power consumption is reduced to about 6 W.

[0011]

As described above, in the conventional example, the video output circuit 7 is not operated in the SUSPEND mode.
The output B voltage of the B voltage stabilizing circuit 1 of FIG.
Because of the FF, the cathode voltage of the cathode electrode 13 of the cathode ray tube 15 (shown by a dashed line) is 0 V as shown in FIG. On the other hand, the heater electrode 14 has a preheat voltage (about 4 V) as shown by the solid line. Therefore, the cathode electrode 13 has a negative potential with respect to the heater electrode 14. When the cathode electrode 13 has a negative potential with respect to the heater electrode 14,
There was a problem that the heater winding of the heater electrode 14 was ionized positively, the core wire became thin, and eventually the wire was broken, and the life of the cathode ray tube 15 was significantly reduced.

To solve the above problems, (1) the output voltage of the B voltage stabilizing circuit 1 of the video output circuit 7 is maintained at a rated voltage without being turned off. (2) The B voltage of the video output circuit 7 is stabilized. Addition of a switching circuit that lowers the output voltage of circuit 1 (3) Addition of a switching circuit that lowers the voltage of cathode electrode 13 to some extent (4) Means such as setting the voltage of heater electrode 14 to a negative potential can be considered. In the case of (1), since the B voltage is supplied to the video output circuit 7 as shown in FIG. 4B, there is a basic problem that the power consumption in the SUSPEND mode increases by 20 W or more. Furthermore, in (2) and (3), the switching circuit is provided, which complicates the circuit.
The circuit becomes complicated, and the heater constant voltage stabilization circuit 3
There is a problem that the output voltage cannot be used as the B voltage of another circuit.

In view of the foregoing, it is an object of the present invention to prevent a reduction in the life of a cathode ray tube with a simple circuit configuration without increasing the power consumption of a cathode ray tube display device in an energy saving operation state.

[0014]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a DC voltage stabilizing circuit 1 having an output voltage ON / OFF function for supplying a B voltage of a video output circuit. Output voltage O that supplies the B voltage of the circuit of FIG.
In a cathode ray tube display device having a DC voltage stabilization circuit 2 having an N / OFF function and a DC voltage stabilization circuit 3 having an output voltage ON / OFF function for supplying a heater constant voltage and a preheating voltage of a cathode ray tube, a diode and a resistor are provided. Is connected between the voltage output terminal of the DC voltage stabilizing circuit 1 and the power input terminal of the DC voltage stabilizing circuit 2, and the diode is connected when the output of the DC voltage stabilizing circuit 1 is OFF. It is characterized by being connected so as to conduct.

[0015]

According to the present invention, a series circuit of a diode and a resistor supplies a B voltage of a video output circuit and a voltage output terminal of a B voltage stabilizing circuit 1 and a B voltage of a vertical output circuit lower than the B voltage. The diode is connected between the power supply input terminals of the B voltage stabilizing circuit 2 and the diode is connected so as to conduct when the output voltage of the B voltage stabilizing circuit 1 of the video output circuit is off, so that the cathode ray tube is connected. The cathode electrode is 10
Since the bias is applied to about V, the cathode electrode has a positive potential with respect to the heater electrode. Therefore, it is possible to prevent the life of the cathode ray tube from being shortened.

[0016]

FIG. 1 is a circuit diagram of a cathode ray tube display device according to an embodiment of the present invention. The same components as those in the conventional circuit diagram of FIG. 3 are denoted by the same reference numerals, and description thereof is omitted. .

The circuit of the present embodiment comprises a diode 16 and a resistor 17
The anode of a diode 16 is connected to a power input terminal (point a) of a B voltage stabilizing circuit 2 for supplying a B voltage of a vertical output circuit 8 via a resistor 17, and a video output circuit Voltage stabilizing circuit 1 for supplying the B voltage of No. 7
Are connected to be the cathode of the diode 16.

The diode 16 and the resistor connected as described above
The operation of the seventeen series circuits 4 will be described.

In the ON STATE mode (normal operation state), the power input terminal (a) of the B voltage stabilizing circuit 2 of the vertical output circuit 8
Since the voltage at the voltage output terminal (point b) of the B voltage stabilizing circuit 1 of the video output circuit 7 is higher than the point (point), the diode 16 becomes non-conductive and the series circuit 4 of the diode 16 and the resistor 17
No current flows through

However, in the SUSPEND mode shown in (Table 2), the transistor 12 is turned on and the video output circuit 7 is turned on.
Since the output B voltage of the B voltage stabilizing circuit 1 is turned off and becomes 0 V, the diode 16 becomes conductive, and the diode 16 is connected to the power input terminal (point a) of the B voltage stabilizing circuit 2 of the vertical output circuit 8. A current flows to the video output circuit 7 through the series circuit 4 of the resistor 17, and the cathode voltage becomes 10 V as shown in FIG. Therefore, the cathode electrode 13 is maintained at a positive potential with respect to the heater voltage of the heater electrode 14 in the preheated state, and the life of the cathode ray tube 15 can be prevented from being shortened.

Also, in the OFF STATE mode shown in (Table 2), current flows through the series circuit 4 of the diode 16 and the resistor 17 and consumes power. Since the power consumption in the STATE mode must be further reduced, the increase in power consumption due to the addition of the series circuit 4 of the diode 16 and the resistor 17 must be minimized. This will be described.

FIG. 2 shows the relationship between the series resistance value, the cathode voltage, and the increase in power consumption in the SUSPEND mode. According to FIG. 2, when the resistance 17 is 0Ω, about 1 W is consumed.
If it is 3.3 kΩ, the increase can be suppressed to about 0.1 W.

That is, it is possible to change the cathode voltage of the cathode electrode 13 by changing the resistance value of the resistor 17 connected in series to the diode 16. The increase in power consumption in the OFF STATE mode shown in Fig. 4 can be minimized.

[0024]

As described above, the cathode ray tube display device of the present invention can be easily connected between the voltage output terminal of the B voltage stabilization circuit of the video output circuit and the power supply input terminal of the B voltage stabilization circuit of the vertical output circuit. By connecting a series circuit of a diode and a resistor with a simple circuit configuration so as to be non-conductive during normal operation and conductive during energy saving operation, the cathode electrode is maintained at a positive potential with respect to the heater voltage during energy saving operation, Can be prevented from being shortened.

Further, there is no need to provide a circuit for switching the output voltage of the B voltage stabilizing circuit of the video output circuit, a circuit for switching the cathode voltage of the cathode electrode, and the like.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a cathode ray tube display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a resistance value of a resistor, a cathode voltage, and an increase in power consumption in a SUSPEND mode in FIG. 1;

FIG. 3 is a circuit diagram of a conventional cathode ray tube display device.

FIG. 4 is a diagram showing changes in a cathode voltage and a heater voltage in each mode, which are a conventional example (a), a video B voltage rating holding or variable voltage type (b), and the present invention (c).

[Explanation of symbols]

1: output voltage ON / supplying the B voltage of the video output circuit
DC voltage stabilization circuit with OFF function, 2 ... DC voltage stabilization circuit with output voltage ON / OFF function to supply B voltage of vertical output circuit, 3 ... Output voltage ON / OFF function to supply heater constant voltage and preheat voltage DC voltage stabilization circuit with 4… Series circuit of diode and resistor,
5 switching power transformer 6 power rectifying and smoothing circuit 7 video output circuit 8 vertical output circuit
9, a transistor for switching the output voltage of the DC voltage stabilizing circuit 3 to the heater electrode preheating voltage,
11, 12: Output voltage O of each DC voltage stabilizing circuit 3, 2, 1
N / OFF switching transistor, 13 ... cathode electrode,
14 ... heater electrode, 15 ... cathode ray tube, 16 ... diode, 17 ... resistance.

Claims (1)

(57) [Claims] 1. A DC voltage stabilizing circuit (1) having an output voltage ON / OFF function for supplying a B voltage of a video output circuit,
A DC voltage stabilizing circuit (2) with an output voltage ON / OFF function for supplying a B voltage of another circuit lower than the B voltage, and an output voltage ON / OFF function for supplying a heater constant voltage and a preheating voltage for a cathode ray tube DC voltage stabilization circuit
(3) In the cathode ray tube display device having the, a series circuit of a diode and a resistor, the DC voltage stabilizing circuit
The diode is connected between the voltage output terminal of (1) and the power input terminal of the DC voltage stabilizing circuit (2) so that the diode conducts when the output of the DC voltage stabilizing circuit (1) is OFF. A cathode ray tube display device characterized by being connected.