MXPA97004554A - Lumin discharge lamp device - Google Patents

Abstract

The present invention relates to a light discharge lamp device which consists of a DC source (direct current) to generate a voltage necessary for a discharge lamp of a DC source, a regulation circuit to calculate the energy required by the discharge lamp to carry out the feedback control on the DC power source, a polarity switching circuit for switching polarities of a DC source output to apply the output to the discharge lamp, a lighter to superimpose a high impulse voltage for the discharge lamp when the discharge lamp is turned on, and a capacitor which forms a closed circuit together with the lighter, where, according to the excessive suppressed charge and discharge currents that flow through the capacitor when the polarities of the polarity switching circuit are switched, the regulation circuit controls the circuit to switch the polarity to be operated at a low frequency and simultaneously to be operated by switch at a high frequency. By this the excessive current flow through the switching elements at the time of switching the polarities can be suppressed and the voltages imposed on the switching elements can be prevented with sufficient

Description

LIGHT DISCHARGE LAMP DEVICE BACKGROUND OF THE INVENTION The present invention relates to light discharge lamp devices and more particularly, to the light discharge lamp device for illuminating a high pressure discharge lamp that requires high pulse voltage application for this in a start mode, such as a high pressure sodium lamp, a haloidal lamp (welding lamp with alcohol or acetylene) or a high pressure mercury vapor lamp.

DESCRIPTION OF THE RELATED ART A prior art of the light discharge lamp device is provided in this type of high pressure discharge lamp, which consists of a DC source, a discharge lamp, a voltage drop cut-off circuit to convert the power voltage from the DC source to a power required for the discharge lamp, first and second resistors to detect a lamp voltage applied to the discharge lamp, a resistor to detect a lamp current flowing through the discharge lamp, and a feedback regulation circuit for controlling the switching elements in the DC source. In this case, the light discharge lamp device calculates the energy needed for the discharge lamp at the bases of the lamp current detected by the lamp current detector resistor and the voltage of the lamp detected by the resistors first and second for the detection of the lamp voltage and carries out the feedback control on a voltage drop cutter circuit to extract the necessary energy. In addition, for the purpose of preventing an acoustic resonance phenomenon of the discharge lamp by means of a polarity commutating circuit to stabilize the discharge arc and prevent a catastrophe phenomenon causing color separation in a light emission area , the luminous device is fixed to supply an AC (alternating current) rectangular wave energy having a low frequency for the discharge lamp. And the polarity switching circuit, which consists of a complete bridge circuit made of up to 4 switching elements and 4 diodes inversely (eg, in their reverse polarity directions) connected in parallel to these switching elements, is driven by a low frequency drive circuit so that two pairs of the pairs of the diagonally linked switching element are alternately set to ON and OFF to reverse the polarities of a voltage to be applied to the discharge lamp. The prior art of the luminous device further includes a lighter to ignite the discharge lamp as superimposed by a high pulse voltage. The lighter, which has an activating circuit such as a pulse voltage generator and a pulse transformer to raise the pulse voltage, is set to superpose a high pulse voltage to the discharge lamp through a capacitor which forms a closed circuit for the application of high impulse voltage.

With the aforementioned arrangement, the capacitor operates to apply the high impulse voltage to the discharge lamp and even acts as a power source to supply a forced discharge current for a rapid transit from the discharge brightness to the arc discharge immediately after the discharge lamp begins its discharge operation. Taking into consideration the above function, in order to improve a starting operation of the discharge lamp, it is effective to increase the capacity of the capacitor by means of this increasing the forced discharge current immediately after the start discharge of the lamp. In any case, the presence of the capacitor also means a problem that in particular, at the time of the polarity switching operation to turn off the discharge lamp, an excessive current flows through the respective switching elements to cause an erroneous operation Of the device. In particular, when the capacity of the capacitor is increased, the problem above becomes serious.

A prior art invention disclosed in the U.S. Patent is also already proposed. No. 4,412,156, which includes a circuit configuration similar to the prior art arrangement. This invention is substantially the same in the arrangements of the voltage drop and polarity switching cut-off circuit, but has a problem as, at the time of failing the polarity switching circuit to contain such a capacitor as mentioned above, it is impossible to insure its download start operation.

A prior art later including substantially the same circuit arrangement as the prior art mentioned above is disclosed in the U.S. Patent. No. 4,734,624. This invention includes a capacitor as in the above prior art arrangement, but the functions for supplying an oscillating current to a discharge lamp such that the light condition of the discharge lamp is maintained during the condition? OFF all switching elements at the time of the polarity switching operation. In this way, since the values of the capacitor and inductor are set so that the oscillation current flows into the discharge lamp during the OFF condition of all the switching elements, the placement of the capacitor capacity can be effected with less flexibility and in this way with a risk of less safety in the starting operation of the discharge lamp. Therefore, it remains a problem that the incorporation of the capacitor, even if small in capacity, causes excessive current to flow through the switching elements to charge and discharge the capacitor at the time of the polarity switching operation to turn off the lamp of discharge in the invention of the US Patent 4,412,156.

However, another prior art is disclosed in Japanese Patent Application Laid-Open Publication No. hei-6-2957906. This prior art invention is signaled, when an impedance of the lamp is low immediately after commencing the discharge operation of the discharge lamp, to detect and suppress an excessive current flowing through the discharge lamp. In other words, only during the excessive current flow through the discharge lamp at the time of turning on the discharge lamp, the switching elements in a polarity switching circuit are in operation by switch at a high frequency to suppress the excessive current from above. In this invention, however, there is a problem that the excessive charge and discharge current of the capacitor can not be effectively suppressed at the time of the polarity switching operation to turn off the discharge lamp.

SYNTHESIS OF THE INVENTION It is therefore a principal object of the present invention to provide a luminous device for a high pressure discharge lamp, which eliminates the above problems in the prior art and where, at the time of turning off the discharge lamp, a charge / discharge current flowing through a capacitor forming a closed circuit for the application of the high impulse voltage cause suppression of an excessive current flowing through switching elements at the time of the polarity switching operation for by means of this preventing the tension of the switching elements and to carry out a stable operation of the light discharge lamp device. Another objective of the present invention is to realize a luminous discharge lamp device which detects a badly inserted discharge lamp and a discharge lamp conformed in normal potential to the luminous device and prevent the deterioration of an operational life of the lamp caused by the difference of energy of the lamp of the luminous device and to avoid a danger of damage to the lamp caused by its erroneous use for by means of this improving a security.

According to one aspect of the present invention, there is provided a light discharge lamp device which consists of a first DC source, a second DC source (such as a voltage drop cutoff circuit) to generate a voltage necessary for a discharge lamp of a first DC source, a feedback regulation circuit to calculate a necessary energy for the discharge lamp to carry out the control by feedback on the DC sources, a polarity switching circuit for switching polarities from an output of the DC source to apply the output to the discharge lamp in the form of a low-frequency rectangular wave, a lighter to superimpose a high pulse voltage for the discharge lamp at the time the lamp is turned on, and a capacitor forming a closed circuit together with the lighter, and where a regulation circuit is provided to operate the switched circuit Polarity at a low frequency and this with switch operation at a high frequency to suppress an excessive charge / discharge current flowing through the capacitor when the polarities of the polarity switching circuit are switched. In the present invention, the polarity switching circuit has, for example, a bridge circuit including switching elements.

With such an arrangement of the invention as explained above, only during the flow of excessive current through the capacitor, the polarity switching circuit is operated at normal low frequency and with high frequency switch operation, so that the current excessive based er. the charging / discharging operation flowing from the capacitor to the switching elements can be suppressed by means of this, reducing the voltage of the switching elements and carrying out a stable operation of the light discharge lamp device.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of the present invention will become apparent from the following detailed description of the embodiments presented thereof in connection with the accompanying drawings, in which: FIGURE 1 is a block diagram showing a basic arrangement of a light discharge lamp device according to the present invention; FIGURE 2 is a circuit diagram of a first embodiment of the present invention; Figure 3 shows the waveforms of the operation signals that appear in the first embodiment of Figure 2; Figure 4 shows the waveforms of the operation signals that appear in the second mode; Figure 5 is a circuit diagram of a third embodiment of the present invention; Figure 6 shows the waveforms of the operation signals appearing in the third embodiment of the present invention of Figure 5; Figure 7 is a circuit diagram of a fourth embodiment of the present invention; Figure 8 is a circuit diagram of an arrangement of a main part of the fourth embodiment; Figure 9 shows the schematic structure of the discharge lamp in the fourth embodiment; Figure 10 is a circuit diagram of an energy input section of the luminous device of the present invention implemented in the form of a product; Figure 11 is a circuit diagram of an improvisation of the energy factor of the luminous device of the present invention implemented as a product; Figure 12 is a circuit diagram of a section of the lighting circuit in the lighting device of the present invention implemented in the form of a product; Figure 13 is a circuit diagram of a fifth embodiment of the present invention; Figure 14 is a diagram for explaining a sixth embodiment of the present invention; Figure 15 is a plan view of a seventh embodiment of the present invention in its assembled condition; Figure 16 is a circuit diagram of an eighth embodiment of the present invention; Figure 17 is a circuit diagram of a fifth embodiment of the present invention; Figure 18 shows the waveforms of the signals that appear in the fifth modality of Figure 17; Figure 19 is a circuit diagram of a sixth embodiment of the present invention; Figure 20 shows the waveforms of the signals that appear in the sixth modality of Figure 19; Figure 21 is a circuit diagram of a seventh embodiment of the present invention; Figure 22 shows the waveforms of the signals that appear in the seventh modality of Figure 21; Figure 23 is a circuit diagram of an eighth embodiment of the present invention; Figure 24 shows the waveforms of the signals to explain a problem to be solved by the eighth modality of Figure 23; Figure 25 shows the waveforms of the operation signals of the eighth embodiment of Figure 23; Figure 26 is a circuit diagram of a modification of the eighth embodiment of Figure 23.

While the present invention will now be described with reference to the embodiments shown in the drawings, it should be appreciated that the intention is not to limit the present invention only to these modes shown, but to include all alterations, modifications and equivalent arrangements possible within of the scope of the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES Figure 1 shows a block diagram of a basic arrangement of a light discharge lamp device according to the present invention, which includes a first DC source 1, a discharge lamp 7, a second DC source 2 for generating a voltage and current necessary for the discharge lamp 7 from the first DC source 1, a regulation circuit 3 for carrying out the control by realization on the second DC source 2, a polarity switching circuit 4 for converting a outputting a second DC source 2 to a rectangular wave AC source and supplying the AC source for the discharge lamp 7, a regulation circuit 5 for controlling the polarity switching circuit 4, a lighter 6 for supplying a high pulse voltage for the discharge lamp 7 as superimposed on it, and a capacitor C2 connected in parallel to a serial circuit of the discharge lamp 7 and cigarette lighter 6.

A detailed circuit configuration of the light device of FIG. 1 is shown in FIG. 2. In the illustrated example, the second DC source 2, which has an invented voltage drop cut-off circuit of a switching element Q5, an inductor Ll and a diode D5, is provided so that, when the switching element Q5 is set to ON and OFF at a high frequency, the control of its ON duration or switching frequency causes the appearance of a required voltage at through a capacitor Cl. An output voltage of the voltage drop cutter circuit is detected by means of a lamp voltage detecting resistors Rl and R2 and an output current of the voltage drop cutter circuit is detected by a lamp current detecting the resistor R3, of so that the feedback regulation circuit 3 controls the ON duration or the switching frequency of the switching element Q5. The polarity switching circuit 4 consists of a complete bypass circuit, which is made of 4 switching elements Ql, Q2, Q3 and Q4 and 4 diodes DI, D2, D3 and D4 connected in reverse polarity direction parallel with the switching elements Ql, Q2, Q3 and Q4 are driven by a low frequency amplifier circuit 51 so that the pairs Ql, Q4 and Q2, Q3 of the switching element diagonally connected are alternately turned ON and OFF to cause a reverse operation of the polarities of a voltage applied to the discharge lamp 7. In addition, for the purpose of prevention of an excessive current of the fluid through the capacitor C2, on the switching of the polarities when the lamp is without light, the polarity switching circuit 4 has operation by switch by means of a high amplification circuit. frequency 52 in the high frequency and even being operated at a normal low frequency.

In Figure 2, when it is desired to illuminate the discharge lamp 7, the second DC source 2 rises to the voltage needed for the discharge lamp 7 to generate a prescribed voltage (such as up to 300V), and then applies the prescribed voltage to the discharge lamp 7 through the polarity switching circuit 4 and the lighter 6. In the polarity switching circuit 4, in this case, the pair of the switching element Ql and Q4 or Q2 and Q3 is set to ON for applying a starting voltage to the discharge lamp 7, at which time the discharge lamp 7 has an impedance Zla of infinity. The switching of the polarity switching circuit 4 is performed, in the illustrated example, at said time as shown in Figure 3. For example, as shown in Figure 3, the switching element Q2 (or Q4) is set ON and then the switching element Q3 (or Ql) is set to ON. When the switching element Q2 (or Q4) is set to ON, it charges to a certain point stored in the capacitor C2 to form a closed circuit together with the igniter 6 which is quickly discharged through the switching element Q2 (or Q4) and the Parasite diode D4 (or D2) of the other switching element Q4 (or Q2) provided to a low potential part. Further, after the capacitor C2 load is fully discharged as mentioned above, the switching element Q1 (or Q3) is set to ON. At this time, a load current flows rapidly from the capacitor Cl provided in an output part of the second source of DC 2 to the capacitor C2 by means of the switching elements then in pairs. For moderating the charging current, according to the present invention, the polarity switching circuit 4 has switch operation by means of a high frequency amplifier circuit 52 at high frequency and is also operated at normal low frequency.

If the switching element Q5 of the second DC source 2 is put in its ON condition during the charging period of the capacitor C2, then the charging current flows rapidly from the first DC source 1 in the capacitor C2. This results in that, during the polarity switching operation of the polarity switching circuit 4, the charging and discharging operations of the capacitor C2 cause the voltage of the switching elements Q1 to Q4 and the Q5 to be increased. To prevent stress, according to the invention as set forth in claim 4, the switching element Q5 is set to OFF from the second DC source 2 during this period.

The embodiments of the present invention will be detailed in accordance with the accompanying drawings. Referring first to Figure 2, a first embodiment of the present invention is shown, which includes the regulation circuit 5 for causing the polarity switch circuit 4 to be operated by a high frequency switch and operated at a normal low frequency. only while an excessive current flows from the capacitor C2 in the polarity switching circuit 4, by this limiting the current flowing through the capacitor C2. In particular, the period of excessive current flow through capacitor C2 is while the lamp is without light, in which (e.g., an output voltage from a second DC source 2) becomes high. The switching operation of the switching elements Ql, Q2, Q3 and Q4 of the polarity switching circuit 4 is performed at that time as shown in Figure 3. It will be seen from Figure 3 that, of the switching elements Ql , Q2, Q3 and Q4 of the polarity switching circuit 4, the switching elements Q1 and Q3 connected to the higher potential part when they receive a signal from the switching elements Q2 and Q4 connected to the lower potential part are set to ON, so that there is necessarily said period that only the switching element Q2 and Q4 connected to the lower potential part is set to ON. At this time, the charge accumulated in the capacitor C2 is discharged through a path of the capacitor C2, the switching element Q2 (or Q4) and the diode D4 (or D2). This discharge current causes the switching element connected to the lower potential part to be turned ON, so that the switching element connected to the lower potential part is operated per switch via the high frequency amplifier circuit. 52 of the regulation circuit 5 in high frequency during a period that the accumulated charge in the capacitor C2 is rapidly discharged. After the switching element connected to the lower potential part is set to ON, if the switching element Ql or Q3 connected to the higher potential part is turned ON, a charging current flows rapidly in the capacitor C2 which becomes zero in its accumulated charge by means of a capacitor Cl path C1 provided in the output phase of the second DC source 2, the switching element Ql (Q3), the capacitor C2 and the capacitor element switching Q4 (Q2). In this case, the switching element connected to the higher potential part is operated by high frequency switch and is operated at low frequency only in a certain time. At this time, the excitation signals for the respective switching elements Ql, Q2, Q3 and Q4 of a switching circuit of polarity 4 are switched at high frequency only during the fast charging and discharging operations of the capacitor C2, and are switched at low frequency, as shown in Figure 3. As a result, the excessive current flowing during the charging / discharging operations of the capacitor C2 can be reduced and in this way the voltage of the switching elements can be illuminated.

A second embodiment of the present invention is shown in Figure 4. After the switching element Q2 (or Q4) connected to the lower potential part is set to ON and the load of the capacitor C2 is fully discharged as mentioned above, the switching element Q3 (or Ql) connected to the highest potential part is put in SWITCHED ON. At this time, a load current flows in capacitor C2 from the capacitor Cl in the output phase of the second DC source 2. Because the load current is excessive, the switching elements Q1 and Q3 have been operated per switch in high frequency and in low frequency in the aforementioned explanation. In the present embodiment, in any way, the switching element Ql or Q3 connected to the higher potential part is operated at normal low frequency, while the switching elements Q2 and Q4 connected to the lower potential part are operated per switch at high frequency even during the flow of the load current through capacitor C2. With respect to the signals then excited for the switching elements Ql, Q2, Q3 and Q4 of the polarity switching circuit 4, only the switching element Q2 or Q4 connected to the lower potential part is operated at low frequency and even It is operated by high frequency switch. (Because the explanation above has been made in this example in connection with the case where there is a time difference between turning the switching elements ON and OFF, the foregoing is applicable even when there is no time difference and the polarities of the opposite switching elements are switched simultaneously.) Figure 5 shows a third embodiment of the present invention. As mentioned above, when the switching element Q4 and Q2 connected to the low potential part is set to ON and then the switching element Q1 and Q3 connected to the higher potential part is turned ON, a charging current flows rapidly in capacitor C2 which becomes null in charge through the capacitor Cl path of the output phase of the second DC source 2, the switching element Ql (or Q3), the capacitor C2 and the element switching Q4 (or Q2). During this charging period, an ON condition of the switching element Q5 of the second DC source 2 causes an abrupt load current flowing from the first power source 1 to the switching element Q5 in the capacitor C2. When the switching element Q5 of the second power source 2 is stopped by a DC source stop circuit 8 only during the fluid of the fast charging and discharging currents through the capacitor C2 as shown in Figure 6 , during which the capacitor C2 is charged by the second power source 2, thereby illuminating the fast discharge current flowing from the first DC source 1 in the capacitor C2. As a result, the voltage of the switching element Q5 of the second DC source 2 as well as the voltage of the switching elements Ql and Q4 of the polarity switching circuit 4 can be reduced. In this conjunction, the excitation signals for the switching elements Q1 and Q4 can be the excitation signals of Figure 4 explained in connection with the second embodiment.

There are several types of discharge lamp in the present, some of which belonging to an identical type are the same with respect to the base or shape despite the different lamp energies. For this reason, it is difficult to know a desired average lamp speed at first glance. When a lamp forming a resistance is not used for said reason, it inconveniently involves the deterioration of the operational life of the lamp. An improvement in this is shown as the fourth modality that follows.

The fourth embodiment of the present invention is shown in Figure 7. In the present embodiment, a detection circuit of the lamp 31 is added, which includes, as shown in Figure 8 for example, resistors Ra and Rb having high resistance high and connected through the switching elements Ql and Q4 which form a pair in the polarity switching circuit 4 respectively, and also includes a resistor Rc provided within the discharge lamp 7 as a means of detecting lighting energy and lamp as shown in Figure 9. With this arrangement, in a switch-off lamp mode, a current flows through a high resistance path Ra, the resistance Rc inside the discharge lamp 7 and high resistance Rb. This current is converted to an average voltage across the lamp current by detecting the resistors R3, and the lamp detection circuit 31 detects a condition of the lamp (light condition or extinguishing condition) of the discharge lamp 7. in the bases of the average voltage to regulate the second DC source 2. When the resistor inside the discharge lamp is placed to have different resistance averages depending on the magnitude of its estimated lamp energy, the estimated lamp energy it can be detected by the lamp detection circuit 31 in the bases of the value of the current flowing through the detection resistor R3. In this way, when the lamp used as a charge conforms to the light discharge lamp device, the light discharge lamp device operates normally; while, when the lamp does not conform to the light discharge lamp device, the light discharge lamp device stops, for example, it stops the switching operation of the second DC source 2 to disconnect the power supply to the light source. load. This allows to avoid the deterioration of the life of the lamp or to prevent the damage of the lamp.

Reference has been made only to a part of the light discharge lamp device without reference to a detailed circuit diagram generally of the first to fourth embodiment above. Here are examples of when these modalities are applied to current light discharge lamp devices.

Figures 10 to 12 show an example of a luminous device which incorporates the present invention in the form of a currently applied product. More specifically, Figure 10 shows a power supply input section, Figure 11 shows an application section of the power factor, Figure 12 shows a lighting circuit section, in which the reference symbols of the drawings Jl to J18 denote connection points for the interconnection between it.

In the input section of the power supply of Figure 10, an AC source connected to the terminals TM1 and TM2 is connected to AC input terminals of the rectifier circuit DB through the fuse FS, a thermal protector TP, low resistance R4 and a filter circuit. The rectifier circuit DB is also connected to its DC output terminals with a capacitor C9 between it. Capacitor C9 has a small capacity and the current filtering operation is carried out by a surge cut-off circuit in the last phase power factor improvement section. The filter circuit includes a surge absorber ZNR (made of zinc oxide having a non-linear resistance characteristic), coils L5 and L6, capacitors C5, C6, C8, C81 and C82. A midpoint between a series circuit of the capacitors C81 and C82 is connected by means of a capacitor C83 to a terminal TM5, which in turn is connected to ground.

The power factor improvement section of Figure 11 consists of an overvoltage or surge circuit which includes an L7 lighter, a switching element Q7 and a diode D7. The surge cut-off circuit receives a full-wave rectified output from a rectifier circuit DB of the point J1 and supplies a DC voltage uniformly raised to an electrolytic capacitor CO (refer to FIG. 12) connected to point J2. The switching element Q7 in the overvoltage cut-off circuit is driven by means of a conductive output of a surge voltage cut-off control circuit 9 through resistors R71 and R72, from which its current is detected by a resistor R73. A current flowing through the lighter L7 is detected through a resistor R74 connected to a secondary winding. In addition, an output voltage appearing at point J2 is detected through resistors R8 and R9, and an input voltage appearing at point J1 is detected through resistors R91 and R92. An operational energy Vccl of the overvoltage cutoff regulation circuit 9 is supplied, and an energy in ON mode, from the point Jl through resistors R93 and R94; whereas, when the switching operation of the switching element Q7 starts, an output of the secondary winding of the inductor L7 is rectified by means of diodes D71 and D72 and a DC voltage obtained through the resistor R7 and the capacitor C71 is supplied to through a diode D73. The DC voltage that appears through the capacitor C71 is converted to a constant voltage by means of a voltage regulator IC1 of a type 3 terminal, and the constant voltage is used as an operational energy Vcc of a regulating circuit of the section of the lighting circuit 53. The regulation circuit of the lighting circuit section 53 detects a null current, an excessive current and a lamp voltage through points J3 to J5 connected to the lighting circuit section shown in FIG. Figure 12, and outputs the rectangular wave excitation signals and a voltage reducing excitation signal through points J6 to J8.

The section of the lighting circuit of Figure 12, which has the voltage drop cutter circuit 2, functions to reduce the DC voltage at point J2 obtained through the electrolytic capacitor CO under an arbitrary DC voltage level by means of of the switching element Q5, the diode D5 and the inductor Ll, where the lamp voltage appears through the capacitor Cl. The lamp voltage that appears through capacitor Cl is detected through resistors Ría and Rl and point J5. In addition, a current flowing through the inductor Ll is detected through the resistor R5 and the point J3, while a current flowing through the voltage drop cutter circuit 2 is detected through a termination of the resistor R3 and the point J4. The switching element Q5 of the voltage drop cutter circuit 2 is driven by an exciting signal supplied to the point J8 by means of a transformer T5 and resistors R51 and R52.

A polarity inverter circuit consists of a complete bridge circuit made of up to 4 switching elements Ql to Q4, which in turn are driven by general operating circuits IC2 and IC3 through resistors Rll, R12; R21, R22; R31, R32; R41, R42. Rectangular wave excitation signals are supplied from points J6 and J7. The control circuits IC2 and IC3 are supplied with the constant voltage Vcc mentioned above as their operating power. The capacitors C11, C12; C31, C32 to handle the switching elements Ql and Q3 connected to the higher potential part are charged with the constant voltage Vcc through a resistor R13 and the diodes Dll and D31. The complete bridge circuit is connected to its outlet part with the discharge lamp 7 through a pulse transformer PT of the igniter circuit 6. The terminals TM3 and TM4 are for the connection of the discharge lamp 7. The lamp 7 is, for example M98 (70W) or M130 (35W) based on the specifications of the "American National Standards Institute" standards. of Patterns) (ANSI) and its light emitting tube is of ceramic type. The pulse generation of the igniter circuit 6 is stopped after the discharge lamp 7 starts its discharge operation.

According to the present invention, in a lifting portion of the rectangular wave driving signal supplied by means of the points J6 and J7 to a pin No. 2 of each of the handling circuits IC2 and IC3, a period is provided for overvoltage cut-off operation to moderate excessive load and discharge currents. During this period, the switching operation of the switching element Q5 is stopped to prevent any excessive current. Although the capacitor C2 is not illustrated in FIG. 12, the turn-off number of a secondary winding of the pulse transformer PT is large and there exists a connection capacitance, whose capacitance acts as the capacitor C2. This goes without saying that, as shown in Figure 2, capacitor C2 can be connected as a separate part.

Figure 13 shows a fifth embodiment in which an inductor L102 is inserted in series with a low voltage side winding N101 of a pulse transformer PT so as to suppress a high frequency oscillation current 1101 flowing through the lateral winding of Low voltage N101 during the discharge operation of a discharge lamp 102.

In the present embodiment, since the inductor L102 is inserted as shown in Figure 13, even when the discharge lamp 102 starts its discharge operation and this causes a reduction of the inductance value of the low voltage side winding N101 of the transformer of pulse PT, the arrangement of the inductor L102 allows the suppression of a current flowing from the capacitors C106 and C105 and thus allows the reduction of a maximum value Ipl02 of the oscillation current 1101. Furthermore, even with respect to a frequency of oscillation contained in a high impulse voltage, since the inductor L102 is provided in a closed circuit of capacitors C106 and C105 and the low voltage lateral winding N101 which defines the oscillation frequency, the oscillation frequency can be set for be low and the start operation of the discharge lamp 102 can be carried out reliably.

As shown in Figure 16 is a sixth embodiment in which the value of the inductor L102 inserted in the fifth mode is prescribed. In Figure 14, abcisa denotes the value of the inductor L102, and ordinary denotes the maximum value Vp and the pulse duration Wp of the high pulse voltage and the maximum value Ipl02 of the oscillation current 1101. As will be seen from Figure 14 , so that the value of the inductor L102 is increased, the oscillation frequency of the high pulse voltage becomes low, so that the pulse duration Wp becomes large and the maximum value Ipl02 of the oscillation current 1101 becomes small . In any case, since a voltage to be developed in the low voltage side winding N101 by means of the oscillation current 1101 flowing through the low voltage part is taken by the inductor L102 to by means of this reduce the value Maximum Vp of high impulse voltage. On the contrary, while the value of the inductor L102 is reduced, the maximum value Vp of the high pulse voltage can be kept high but the oscillation frequency becomes high, which results in the pulse duration Wp becoming narrow and the maximum value Ipl02 of oscillation current 1101 becomes large.

Assume now that the maximum value of the high pulse voltage necessary to turn on the discharge lamp 102 is denoted by Vpmin, the pulse duration of the high pulse voltage is by Wpmin, the maximum allowable current value of the capacitor C105 is by Ipl02max, and the maximum value of the inductor L102 in a structurally realizable coil size is by L102max. Then the optimal design points are as shown in the drawing. In this connection, since the maximum allowable ranges of the maximum value and pulse duration of the high target pulse voltage and the maximum allowable range of the maximum value Ipl02 of the oscillation current vary greatly from resistance to resistance, the specific numerical value of the inductor L102 is not specifically given in this.

Figure 15 is a seventh embodiment, showing a condition of a printed circuit board 3 in which the circuit of the aforementioned first and second modes is mounted. A point to be more noticed at the time of mounting the circuit on a printed circuit board is a path through which the oscillation current 1101 flows. That is, that the high frequency oscillation current 1101- has a high possibility of generating noise, said circuit must be mounted separately from other electronic parts or patterns. In the present embodiment, the other electronic parts and patterns are fixed in the form of not being presented in a closed circuit of the capacitor C106, the switching element Q106, the inductor L102, the capacitor C105 and the low-voltage side winding N101 of the transformer of pulse PT, through which the high frequency oscillation current 1101 flows in closed circuit. With this arrangement, the circuit can be prevented from operating erroneously during the high frequency oscillation current and a discharge lamp device can be provided luminous which is reliably capable of lighting the discharge lamp.

Although the explanation has been made in connection with the case where the conventional resistance is used as the main resistance the preceding modes for the good convenience of explanation, it has already been found that, even when an electronic resistance is used in the device of luminous discharge lamp, substantially the same effects as those above can be carried out.

Figure 16 shows an eighth mode in which an electronic resistance is used as a main resistance and a lighting circuit is based on a complete bridge system. The operation of this system is substantially the same as that of the prior art one and in this way the explanation thereof is omitted. Even the present embodiment can exhibit the same effects as in mode 5 and maintain the feature that the present embodiment can be made small in size, which results from the inherent merit of electronic resistance.

Figure 17 shows a ninth embodiment in which the complete bridge circuit in mode 8 is provided as divided into the section of the voltage drop cutter circuit 120 and a reversing polarity circuit section 121. Shown in Figure 18 are shapes of wavelengths of operational currents of switching elements Q101 to Q105 as well as a waveform of a lamp current. The operation of the circuit of Figure 17 will be explained briefly below.

The illustrated light-bulb section includes the voltage drop cut-off circuit section 120, the polarity reversing circuit section 121 and a discharge lamp start circuit 122. The voltage drop cut-off circuit section 120, which has the switching element Q105, a diode D105, an inductor LlOl and a capacitor ClOl, is set so that, when the switching element Q105 is in its ON condition, a current flows from a capacitor C100 through the inductor LlOl. to the ClOl capacitor, wherein, when the switching element Q105 is in its OFF condition, an energy up to a certain point accumulated in the inductor LlOl is discharged into the ClOl capacitor through the diode D105. By controlling the pulse duration or the switching frequency of the switching element Q105, the capacitor voltage ClOl, for example, the voltage of the lamp can be adjusted.

The polarity inverter circuit section 121 consists of a complete bridge circuit including switching elements Q101 to Q104. In the polarity inverter circuit section 121, the switching elements Q101 to Q104 perform said operations as shown in FIG. 18 so as to supply the illustrated rectangular wave AC power to the discharge lamp 102. With the disposition as mentioned above, even the present modality may exhibit the same effects as in modality 8.

Shown in Figure 19 is a tenth embodiment in which a luminous lamp section consists of the middle bridge circuit as shown. Figure 20 shows the waveforms of the ON and OFF operational currents of the switching elements Q101 and Q102 as well as a waveform of a lamp current. The operation of the circuit of Figure 19 will be explained below. The switching elements Q101 and Q102 repeat said high frequency switching operation as shown in Figure 20. That is, these switching elements Q101 and Q102 correspond to the switching elements Q105 and Q101 to Q104 in the circuit of the Figure 17. In a cycle during which the switching element Q101 is switching to a high frequency, the energy stored in the inductor LlOl is fed back to the capacitor C104 through the diode D102 in the OFF condition of the switching element Q101. In this way, in a cycle during which the switching element Q102 is switching to a high frequency, the energy stored in the inductor LlOl is fed back to the capacitor C104 through the diode D102 in the OFF condition of the switching element Q101. Whereas, diodes D101 and D102 perform the same function as diode D105 in the circuit of Figure 17.

In the present embodiment when the switching elements Q101 and Q102 each consist of an integrated diode type element such as FET, the diodes D101 and D102 can be replaced with the integrated diodes, whereby the total number of switching elements and diodes to be used it becomes 2 and that way it can be reduced when comparing to 6 in the modality 9, which guides advantageously for reduction of payments and decrease in size.

Figure 21 shows an eleventh embodiment in which the starting circuit of the discharge lamp 122 is set so that a sum of charge voltages developed through the capacitors C106 and C102 causes the ON to turn on a switching element Q106 for apply to the low voltage side winding N101 of the pulse transformer PT a voltage roughly twice as high as the voltage of the preceding mode.

The explanation will be made as the operation of the above circuit system also referring to Figure 22 showing a waveform diagram. The switching elements Q101 to Q104 are operated in such a way that the elements Q101 and Q104 or Q102 and Q103 set diagonally in torque are switched at a high frequency, as illustrated. In this way, a rectangular wave AC voltage applied to the starting circuit of the discharge lamp 122 is as shown in the drawing. In this case, since the capacitor C102 is connected in parallel to the input terminals of the start-up circuit of the discharge lamp 122, a voltage Vcl02 applied to the capacitor C102 is the same as the rectangular-wave AC voltage. Meanwhile, the capacitor C106 repeats its loading and unloading operations through the low voltage side winding N101 of the pulse transformer PT, the resistor R106 and the inductor L102 to eventually generate a waveform as shown by Vcl06 in the drawing. A voltage applied to the switching element Q106 corresponds to a sum of voltages that appear through the capacitors C106 and C102. In any case, in the stable duration of the rectangular wave, the capacitors C106 and C102 have opposite polarities, so that the applied voltage corresponds to ¡Vcl02j - ¡VclOßj that does not reach the inrush voltage of the switching element Q106, by means of the which element Q106 will not be set to ON. At this time, when the polarity of voltage Vcl02 is inverted, the voltage Vcl02 of capacitor C102 is also inverted almost at the same time, with the result that a voltage Vs of ¡Vcl02¡ + ¡Vcl06¡ as shown in the drawing is applied to the switching element Q106, that is, the voltage Vs reaches the inrush voltage of the switching element Q106, thereby turning ON the switching element Q106. As a result, an impulse current flows through the low voltage side winding N101 of the pulse transformer PT and thus said pulse overvoltage as illustrated is induced in a high voltage side winding N102. In the aforementioned circuit system, since a voltage can be applied to the low voltage side winding N101 of the high voltage pulse transformer PT roughly twice as high as the rectangular wave voltage, the pulse transformer PT can be Smaller size than the previous circuit system.

Despite this the luminous lamp section has comprised the complete bridge circuit in the present embodiment, the illumination section can be made of the section of the voltage drop cutter circuit and the section of the polarity inverter circuit as already explained in mode 10. Similarly, the lighting section may comprise said middle bridge circuit as mentioned in mode 10.

Figure 23 shows a twentieth modality. In the preceding embodiment 11, the following problem is present. The problem occurs when the polarities are reversed, the switching elements Q101 or Q103 connected to the highest potential part of the first pair of switching element set diagonally first is turned OFF and then the switching element Q102 or Q104 of a second pair connected to the lower potential side part is set to ON, after which the switching element Q104 or Q102 of the first pair connected to the lower potential part is turned OFF and then the switching element Q103 or Q101 connected the highest potential part is set to ON. Assuming now that, for example, the pair of switching element Q101 and Q104 is in its ON condition. Then the reversal of polarity causes the switching element Q101 to be turned OFF and the switching element Q102 to be turned ON. Then since the switching elements Q102 and Q104 connected to the lower potential part are set to ON, a closed circuit is established on the low voltage side of the bridge circuit. In the closed circuit, due to the LC resonance oscillation caused by the capacitor C106, the inductor L102, the capacitance of connections contained in the inductor L102, the parasitic capacitance of the switching element Q106, the low-voltage side winding N101 of the transformer of impulse PT and the inductor LlOl; the resonant voltage as shown in Figure 24 is inevitably applied at both terminations of the switching element Q106. This circuit system is normally set so that an inrush voltage Vbo of the switching element Q106 satisfies the ratio of ¡Vcl06¡ < Vbo < | V102¡ + VclOßj, where, only when the polarities of the rectangular wave voltage are inverted, the switching element Q106 is set to ON. At this time, if said resonant voltage as shown in Figure 24 is applied to the switching element Q106, the switching element Q106 is undesirably set to ON at this point, whereby the charge stored in the capacitor C106 is undesirably discharged. . In this case, the voltage applied to the low voltage side winding N101 of the pulse transformer PT is only Vcl02 which is smaller than the original Vcl02¡ + VclOßj and reduces the maximum value of the high pulse voltage.

In the present embodiment, a capacitor C107 is connected in parallel to the inductor L102 to prevent the application of an irregular resonant voltage through the switching element Q106 even when the switching elements connected to the lower potential part are simultaneously set to ON at the moment of the polarity reversal, thus realizing the generation of a predetermined high pulse voltage. That is, in view of the fact that the connecting capacitance of inductor L102 contributes in part to the resonant frequency of the resonant voltage, capacitor C107 is connected in parallel to inductor L102 to reduce the resonance frequency (also reference to Figure 25).

Although the explanation has been made in connection with the luminous lamp section consisting of a complete bridge circuit in the present embodiment, the illumination section may be a combination of the voltage drop cut-off circuit section 120 and the circuit section polarity inverter 121 as shown in Figure 26, exhibiting substantially the same effects as those above.

In the above embodiments 5 to 12, reference has been made only to part of the light discharge lamp device without reference to its fully detailed circuit diagram. Either way, it will actually be appreciated that, when the present invention is applied to a light discharge lamp device for example, the arrangements of Figures 10 to 12 can be employed as the modes 1 to 4 below.

Claims (16)

R E I V I ND I C A C I O N S

1. A luminous discharge lamp device comprising: a discharge lamp; a first DC source; a second DC source to supply the energy needed for the discharge lamp of the first DC source; a first regulation circuit for controlling the second DC source; a polarity switching circuit for converting an output of the second DC source to a rectangular wave AC power to supply the AC power of the discharge lamp; a second regulation circuit for controlling the polarity switching circuit; a lighter connected in series between an output of the polarity switching circuit and the discharge lamp for superposing a high pulse voltage on the discharge lamp when the discharge lamp is turned on; a capacitor connected in parallel to a serial circuit of the discharge lamp and the lighter to form a closed circuit, and intermittent power connection supply means for the discharge lamp at the time of the polarity switching operation.

2. A luminous discharge lamp device, as claimed in clause 1, characterized in that the second DC source consists of a voltage drop cutter circuit.

3. A luminous discharge lamp device, as claimed in clause 1, characterized in that the polarity switching circuit consists of a complete bridge of 4 solid states which is made of a series circuit of a first switching element connected to a positive side of the second DC source and a second switching element connected to a negative side thereof as well as a serial circuit which is made of a third switching element connected to the positive side of the second DC source and to a fourth switching element connected to the negative side of this, a serial circuit of said discharge lamp and the lighter is connected between a point of attachment of said first and second switching element and a point of attachment of said third and fourth switching elements , such that said state in which the first and fourth switching elements are in their ON condition and the second and third The switching elements are in their OFF condition and a condition in which the first and fourth switching elements are in their OFF condition and the first and fourth switching elements are in their ON condition alternately take place at a low frequency. to perform the polarity switching operation, and at least a pair of the switching elements set to ON at the time of the polarity switching operation is set to ON and OFF and then set to ON at a low frequency.

4. In addition, it comprises means for stopping the operation of said second DC source for a predetermined time at the time of the polarity switching operation.

5. A light discharge lamp device, as claimed in clause 1, characterized in that the discharge lamp partly incorporates light detection means or average energy sensing means.

6. A luminous discharge lamp device, as claimed in clause 1, characterized in that said discharge lamp is a high pressure discharge lamp.

7. A luminous discharge lamp device, as claimed in clause 6, characterized in that said high pressure discharge lamp is a metal halide lamp.

8. A luminous discharge lamp device, as claimed in clause 7, characterized in that said high pressure discharge lamp has an average M98 (70W) or M130 (35W) based on the specifications of the ANSI.

9. A luminous discharge lamp device, as claimed in clause 6, characterized in that the high pressure discharge lamp is a ceramic light emission tube.

10. A light discharge lamp device comprising: a discharge lamp; a first DC source; a second DC source including a voltage drop cut-off circuit to supply the energy needed for the discharge lamp of the first DC source; a first regulation circuit for controlling the second DC source; a polarity switching circuit for converting an output of the second DC source to a rectangular wave AC power to supply the AC power of the discharge lamp; a second regulation circuit for controlling the polarity switching circuit; a lighter connected in series between an output of the polarity switching circuit and the discharge lamp for superimposing a high pulse voltage on the discharge lamp when the discharge lamp is turned on; a capacitor connected in parallel to a serial circuit of the discharge lamp and the lighter to form a closed circuit, and intermittent power supply connection means for the discharge lamp at the time of the polarity switching operation, and wherein said polarity switching circuit consists of a complete bridge circuit of 4 solid states which is made of a series circuit of a first switching element connected to a positive side of the second DC source and a second switching element connected to a negative side of this as well as to the series circuit which is made of a third switching element connected to a positive side of the second DC source and a fourth switching element connected to the negative side of this, a series circuit of the discharge lamp and the lighter is connected between a junction point of the first and second switching elements and a junction point of the third and fourth switching elements, in such a way that a condition in which the first and second switching elements are in its ON condition and the second and third switching elements are in their OFF condition and a condition in which the first and fourth switching elements are in their OFF condition and the first and fourth switching elements are in their ON condition alternately take place at a low frequency to carry out the polarity switching operation, and at least one of the pairs of the switching elements set to ON at the time of the polarity switching operation is turned OFF and then set to ON at low frequency, said discharge lamp is a metal halide high pressure discharge lamp which has a speed of both, one of an M98 (70W) and one M130 (35W) based on the specifications of the ANSI and has a ceramic light emission tube.

11. A luminous discharge lamp device consisting of: a resistor connected to the power source and containing at least one current limiting element; a discharge lamp requiring a high pulse voltage at least at the time of lighting the discharge lamp; Y a starting circuit of the discharge lamp, where the resistance, the discharge lamp and a high-voltage side winding of a transformer for the generation of a high impulse voltage are present in a closed circuit, a capacitor A repetitively carries out its charge / discharge operations based on an output of the resistor, a series circuit of at least one switching element and a low voltage side winding of the transformer is connected in parallel to capacitor A, and a capacitor B is connected in parallel to the low voltage side winding of the transformer, an inductor is connected in series with the low voltage side winding of the transformer, and a series circuit of the low voltage side winding of the transformer and inductor is connected in parallel to capacitor B.

12. A light discharge lamp device, as claimed in claim 11, characterized in that the inductor is set to suppress a current flowing through the capacitor B at a brightness of a discharge mode of the discharge lamp and to maintain a level of voltage and a pulse width necessary to turn on the discharge lamp.

13. A light discharge lamp device, as claimed in clause 11, characterized in that other parts are mounted on a printed circuit board so as not to be presented in the closed circuit of the inductor, capacitor B and the low side winding Transformer voltage.

14. A luminous discharge lamp device, as claimed in clause 11, characterized in that it further comprises an inverter circuit section which includes the DC source, at least one switching element, a diode, a first inductor and a first capacitor and rectangular wave AC power supply for the discharge lamp, and wherein, in the starting circuit of the discharge lamp, a series circuit is made of at least one feedback element of voltage, a second inductor, a second capacitor and the low-voltage side winding of the transformer for the generation of a high pulse voltage, the serial circuit is connected to an output terminal of the inverter circuit section so that, at the moment of inverting the output polarities, a sum of charge voltages across the first and second capacitors causes the voltage response switching element to be able to or ON to apply the high impulse voltage to the discharge lamp from the high voltage side winding for the generation of the high impulse voltage connected in series with the discharge lamp.

15. A luminous discharge lamp device, as claimed in clause 14, characterized in that the inverter circuit section comprises a reversing polarity circuit section which includes a part of the voltage drop cutter circuit for converting an energy of DC to a voltage necessary for the discharge lamp and at least 4 switching elements, 2 of the 4 switching elements connected to a lower potential part of the polarity reversing circuit section both simultaneously set to ON at the time of polarity reversal, a third capacitor is connected in para to a second inductor in the starting circuit of the discharge lamp.

16. A luminous discharge lamp device comprising: a discharge lamp that requires the application of a high impulse voltage for this at least at the moment of starting the discharge lamp; Y a starting circuit of the discharge lamp having an inverter circuit section to generate the high impulse voltage necessary at the time of lighting the discharge lamp, and wherein the section of the inverter circuit includes a DC source, at least one switching element, a diode, a first inductor and a first capacitor and supplies a rectangular wave AC power for the discharge lamp, and wherein, in the starting circuit of the discharge lamp, a series circuit is made of at least one voltage response switching element, a second inductor, a second capacitor and a low voltage side winding of a transformer for the generation of a high impulse voltage, the serial circuit section is connected to an output terminal of the inverter circuit section so that, at the time of inverting output polarities, a sum of voltages charge through the first and second capacitors causes the voltage response switching element to be set to ON to apply the high impulse voltage to the discharge lamp of a high-voltage side winding to the generation of a high impulse voltage connected in series with the discharge lamp, the inverter circuit section includes a part of voltage drop cutter circuit for converting a DC power to a voltage required for the discharge lamp and a polarity reversing circuit part having at least 4 switching elements, 2 of the 4 switching elements connected to the lowest potential part of the polarity reversing circuit part both put ON simultaneously at the time of polarity reversal, a third capacitor is connected in parallel to the second inductor in the start circuit of the discharge lamp, the discharge lamp is a metal halide high pressure discharge lamp, this haloidal metal high pressure discharge lamp has a speed of both, one of an M98 (70W) and one M130 (35W) based on the ANSI specifications and has a ceramic light emission tube.