JPH06283280A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To provide a discharge lamp lighting device by which a user can be informed of the service life of a lamp by detecting it and which can quickly cope with replacement and the like of the discharge lamp. CONSTITUTION:A voltage signal of a light sensor 3 in proportion to light flux of a discharge lamp 3 in the last period of the service life does not exceeds reference voltage Vref, and exceeds it only temporarily by an output increase after an operation period T of a timer 15 passed, so that output of a comparator 14 is put on 'L' after being transferred to stationary lighting. Output of a NAND circuit 16 maintains 'H' even after output of the timer 15 is put on 'L', so that lighting of a light emitting diode LED of a display part 11 is continued. By the continuance of lighting of the light emitting diode LED, a user can be informed of the fact that the discharge lamp 3 completes the service life.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp lighting device.

[0002]

2. Description of the Related Art FIG. 12 shows a discharge lamp used as a vehicle headlight.
Shows the basic configuration of the discharge lamp lighting device for lighting
In this conventional example, four switching elements Q₁~ Q_Four
Common full bridge constructed by connecting bridges
Type rectangular wave inverter circuit 1 in FIG.
As shown in (b), the switching element Q₁, Q₃At the same time
Switching element Q₂, Q_Four
Is off and the switching element Q₂, Q_Four
Switching on and off at the same time, switching element Q ₁,
Q₃Is turned off.
Source V_DCIs converted into a rectangular wave voltage shown in FIG.
Supplied to the gnita 4.

When the charging voltage of the capacitor C ₂ exceeds the breakover voltage of the switch element S, the igniter 4
The closed circuit of the capacitor C ₂ , the pulse transformer Tr, the switch element S, and the capacitor C ₂ discharges the charging charge to generate a pulse voltage of several tens of kV across the pulse transformer Tr, and the discharge lamp 3 is in a hot state ( Even when the discharge lamp 3 is kept on and immediately after it is turned off, a lamp that can be instantly restarted is used.

The control circuit 5 connects the both ends of the discharge lamp 3 through the pulse transformer Tr of the igniter 4 to the lamp voltage detection circuit 2 to change the lamp voltage of the discharge lamp 3 to the capacitor C of the LC resonance circuit of the inverter circuit 1. _The switching elements Q _{1 to} Q ₄ are PWM-controlled so as to have the characteristics shown in FIG. In this PWM control, the voltage V ₂ obtained after the detection output V ₁ proportional to the lamp voltage output from the lamp voltage detection circuit 2 is passed to the amplifier A or B is input to the PWM signal conversion circuit 6 and converted into a PWM signal. The converted PWM signal is input to the drive circuit 7, the logical product is obtained with the rectangular pulse generated in the oscillation circuit 8 of the drive circuit 7, and the logical product output is switched by the switching Q.
It is performed by setting the driving signals of _{1 to} Q ₄ .

Here, in the initial stage (when the lamp voltage is low) where a large output is required, control is performed so as to show the characteristic as shown in A of FIG. 14, and when it is stable (when the lamp voltage is high), It is controlled so as to show such characteristics. That is, when the lamp voltage is low, the voltage V ₂ obtained by passing the detection output V ₁ proportional to the lamp voltage output from the lamp voltage detection circuit 2 to the amplifier A or B increases and the duty of the PWM signal increases, As a result, the output of the inverter circuit 1 becomes large and the luminous flux of the discharge lamp 3 is rapidly raised as shown by a in FIG. Further, when the lamp voltage is high, the voltage V ₂ is low and the duty of the PWM signal is narrowed, so that the output of the inverter circuit 1 is set to the rated value. Incidentally, A and B in FIG. 14 correspond to the outputs of the amplifiers A and B.

As described above, the operation of rapidly raising the luminous flux immediately after lighting is effective for a headlight of a vehicle that requires a large luminous flux immediately after lighting. FIG. 15B shows the case where the light flux is not rapidly raised immediately after this lighting, and it cannot be used as a vehicle headlight unless the light flux is rapidly raised as in this case.

[0007]

The above-described discharge lamp lighting device makes it possible to use the discharge lamp as the headlight of a vehicle by rapidly raising the luminous flux immediately after lighting. There is a possibility that the discharge lamp may suddenly turn off due to the end of its life because it has no means for detecting and notifying it in advance before it goes out due to its life.

[0008] That is, if such turning off occurs, a problem will occur in the safety of running the vehicle. The present invention has been made in view of the above problems, and the purpose thereof is to detect the lamp life and notify the user, and it is possible to promptly take measures such as replacement of the discharge lamp. And a discharge lamp lighting device.

In particular, the inventions of claims 3 to 5 provide a discharge lamp lighting device capable of performing life detection display at the starting lighting timing of the discharge lamp and improving safety by promptly replacing the discharge lamp. To provide.

[0010]

According to a first aspect of the present invention, there is provided a discharge lamp lighting device comprising a power supply and a lighting circuit for excessively supplying electric power to the discharge lamp when the lamp voltage is lower than a rated value. After the power is turned on, lighting state detection means for detecting an element indicating the lighting state of the discharge lamp within a predetermined time,
And a means for notifying when the detection amount of the lighting state detecting means is out of a predetermined value.

According to a second aspect of the present invention, in the first aspect of the present invention, an element indicating the output state of the discharge lamp is detected, and if the detected value is out of a predetermined value, it is notified by a display. According to the invention of claim 3, in the invention of claim 1, the time until the discharge lamp starts discharging after the power is turned on is detected as the above-mentioned element, and if the detected time is out of a predetermined value, it is notified by a display. Is.

According to a fourth aspect of the present invention, in the first aspect of the invention, the luminous flux of the discharge lamp, the lamp voltage, and
Either the lamp current or the lamp power is used to detect this element after a certain period of time has passed since the discharge lamp started discharging, and if the detected value is outside the predetermined value, it is notified by a display. According to a fifth aspect of the present invention, in the first aspect of the present invention, the lighting device is provided with a plurality of HID lamps as discharge lamps. Is detected, and if the difference between the light fluxes is larger than a predetermined value, the display notifies.

[0013]

According to the invention of claim 1 and the invention of claim 2, after the power is turned on, the life of the discharge lamp can be detected by detecting the lighting state of the discharge lamp, and the detection result is displayed to the user. Since the notification is given, the user can promptly take measures such as replacement of the discharge lamp.

According to the third aspect of the present invention, the life of the discharge lamp can be detected before the start of lighting of the discharge lamp. Therefore, the user is urged to take prompt measures such as replacement of the discharge lamp. It is possible to improve the safety when the headlight is used for lighting the headlight. According to the invention of claim 4,
It is possible to detect the life of the discharge lamp in a short time immediately after the discharge lamp is started and lit, and prompts the user to take measures such as prompt replacement of the discharge lamp, and use it to turn on the vehicle headlights. The safety of the case can be improved.

According to the invention of claim 5, the life of the discharge lamp can be detected in a short time immediately after the discharge lamp is started and lit, and the user is urged to take prompt measures such as replacement of the discharge lamp. In addition, it is possible to improve the safety when used for lighting the headlight of a vehicle, and moreover, it is possible to easily detect the life of a plurality of discharge lamps.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 shows a circuit configuration of this embodiment of the present invention used for a vehicle headlight. This embodiment is based on the inverter circuit 1, the control circuit 5, and the drive circuit 7 in the circuit of FIG. H is started by a lighting circuit 9, an igniter 4, a DC power supply V _DC composed of a car battery, and a pulse generated by the igniter 4, and lighting is maintained by the output of the lighting circuit 9.
The discharge lamp 3 includes an ID lamp, a lighting state detection unit 10 that detects a lighting state of the discharge lamp 3, and a display unit 11 that receives an output from the lighting state detection unit 10 and displays a message to a user. A HID lamp is used as the discharge lamp 3.

As in the conventional circuit, the lighting circuit 9 makes the output excessive during the low lamp voltage immediately after the power switch SW is turned on to rapidly increase the luminous flux of the discharge lamp 3,
After that, when the lamp voltage becomes higher, the output is set to the rated output and the discharge lamp 3 is lit at the rated power. The lighting state detection unit 10 converts the voltage signal proportional to the amount of the luminous flux Φ of the discharge lamp 3 by the optical sensor 13 arranged in the lamp body 12 in which the discharge lamp 3 is mounted, and the level of this voltage signal. And a reference voltage Vref which is set lower than the voltage signal level of the optical sensor 13 corresponding to the permissible value of the luminous flux during normal lighting of the normal discharge lamp 3 and the comparator 14
If the level of the voltage signal is equal to or higher than the reference voltage Vref, the luminous flux detection circuit for generating an output from the comparator 14,
It is composed of a timer 15 which counts a fixed time T (several seconds) from the time when the power switch SW is turned on, and a NAND circuit 16 which performs a NAND operation of the inverted output of the timer 15 and the output of the comparator 14.

In the display section 11, the output of the NAND circuit 16 is "
The light emitting diode LED is turned on when it becomes "H". Next, the operation of the lighting state detection unit 10 and the display unit 11 will be described. First, when the discharge lamp 3 is normal, the power switch SW is turned on. When turned on, the timer 15 of the lighting state detection unit 10 starts operating and outputs the timer output of "H" for a predetermined time T as shown in FIG. 2 (a).
During this "H" period, the NAND circuit 16 receives the "L" signal obtained by inverting the timer output, and therefore outputs the "H" output as shown in FIG. 2C regardless of the output of the comparator 14. ,
As shown in FIG. 2D, the light emitting diode L of the display unit 11
Turn on the ED.

On the other hand, when the power is turned on, the lighting circuit 9 and the igniter 4 start their operations to start the lighting of the discharge lamp 3. While the lamp voltage at the beginning of starting lighting is low, the lighting circuit 9 increases the output in order to rapidly increase the luminous flux Φ of the discharge lamp 3. Therefore, the luminous flux Φ of the normal discharge lamp 3 sharply rises as shown in FIG. The optical sensor 13 of the lighting state detection unit 10 outputs a voltage signal proportional to the luminous flux Φ, but since the voltage signal does not exceed the reference voltage Vref at the beginning of power-on, the output of the comparator 14 is shown in FIG. ) Is "L" as shown in FIG.
During a certain period T when the timer output of 5 is generated
H ".

The timer 15 inverts its timer output to "L" after a lapse of a certain period of time T. By this inversion, the input on the timer 15 side of the NAND circuit 16 becomes "H". Therefore, the result of the NAND operation with the input on the side of the comparator 14 which is already "H" becomes "L", and therefore the light emitting diode LED of the display unit 11 is turned off. In other words, the life of the discharge lamp 3 is determined at the time when the fixed period T has elapsed, and in this case, the light emitting diode LED is turned off, so that the user knows that it is normal at the time when several seconds have elapsed since the power was turned on. It is possible.

When the discharge lamp 3 is at the end of its life, even if the output from the lighting circuit 9 increases during the lighting start period, the luminous flux Φ of the discharge lamp 3 cannot be expected to rise sharply and changes as shown in FIG. To do. Therefore, the voltage signal of the photosensor 3 proportional to the luminous flux Φ of the discharge lamp 3 does not exceed the reference voltage Vref, and only temporarily exceeds by the output increase after the operating period T of the timer 15, and after the steady lighting transition. The output of the comparator 14 becomes "L" as shown in FIG.

Therefore, the output of the NAND circuit 16 is as shown in FIG.
As shown in (f), one period after the lapse of the certain period T ”
The output of the NAND circuit 16 is "H" after that.
To maintain. As a result, as shown in FIG. 2 (g), the light emitting diode LED keeps lighting, and informs the user that the discharge lamp 3 has reached the end of life and prompts replacement of the discharge lamp 3. In the case of the discharge lamp 3 at the end of its life, the output of the NAND circuit 16 is output as shown in FIG. "H" as indicated by the broken line at
The state is continued, and the lighting state of the light emitting diode LED continues from the time of power-on.

(Embodiment 2) In Embodiment 1, the end of life is detected depending on whether or not the luminous flux of the discharge lamp 3 has decreased when a certain time T has passed since the power was turned on. The embodiment is intended to detect and display that the starting performance is deteriorated due to an increase in the pressure inside the lamp due to the life of the lamp or the like, and specifically, the lighting state is detected by detecting the lamp current to determine the end of life. It's something to discover.

That is, the lighting state detection unit 10 of this embodiment is
As shown in FIG. 4, a current detecting transformer CT is provided between the discharge lamp 3 and the igniter 4, and the secondary output voltage proportional to the lamp current of the current detecting transformer CT and the lamp current in a normal state are preset. The comparator 14 compares the reference voltage Vref set corresponding to the lower limit value with the reference voltage Vref.
AND circuit 17 outputs the logical product of the output of
The flip-flop 18 is set by the output of the AND circuit 17. The flip-flop 18 outputs the inverted Q output to the light emitting diode L of the display unit 11.
Drive the ED.

When the power switch SW is turned on,
The timer 15 produces the timer output shown in FIG. The flip-flop 18 is adapted to be reset at the same time when the power is turned on. Upon resetting, the inverted Q output becomes "H" as shown in FIG.
It does not reverse until the output of 7 rises to "H". The light emitting diode LED of the display unit 11 is turned on after the power is turned on.

However, as described above, since the lighting circuit 9 performs the operation of making the output excessive and rapidly raising the luminous flux of the discharge lamp 3 at the time of starting lighting, in the case of the normal discharge lamp 3, it is proportional to the lamp current. The secondary output voltage of the current detecting transformer CT exceeds the reference voltage Vref, and the comparator 14 produces an output of "H" as shown in FIG. 5B. Therefore, the output of the "H" causes the output of the AND circuit 17 to become "H" as shown in FIG. 5C, and the flip-flop 18 is set by the rise of the "H" output.
The inverted Q output becomes "L", and the light emitting diode LED of the display unit 11 is turned off.

This extinguishment is maintained until the flip-flop 18 is reset, indicating to the user that the discharge lamp 3 is normal. On the other hand, if the discharge lamp 3 is at the end of its life, as shown in FIG.
Even if the output of the timer 15 becomes "L" after passing, the output of the comparator 14 is still "L" as shown in FIG. 6B because the lamp current does not increase. Therefore, the output of the AND circuit 7 maintains "L" as shown in FIG. 6C, and the flip-flop 18 is not set. Therefore, the inverted Q output of the flip-flop 18 maintains "H" as shown in FIG. 6 (d), and the light emitting diode LED of the display unit 11 continues to light.

By continuing this lighting, the user can discharge the discharge lamp 3
Is in the end of life and prompts the effect of the discharge lamp 3. As described above, in the present embodiment, the life of the discharge lamp 3 is determined by whether or not the discharge lamp 3 is normally turned on after a lapse of a certain time T after the power is turned on. (Embodiment 3) In this embodiment, the end of life of the discharge lamp 3 is detected by the lamp voltage of the discharge lamp 3. As shown in FIG. 7, the lighting state detector 10 is provided in the lighting circuit 9. A voltage signal proportional to the lamp voltage is generated from the lamp voltage detection unit 19, and the comparator 14 compares the voltage signal with the reference voltage Vref set corresponding to the allowable value of the lamp voltage of the normal discharge lamp 3. It has become. The output of the comparator 14 and the output of the timer 15 are ANDed in the AND circuit 17, and the flip-flop 18 is set by the output. The inverted Q output of the flip-flop 18 and the inverted output of the timer 15 are logically ANDed by the AND circuit 20, and the light emitting diode LED of the display unit 11 is turned on by the output.

Thus, in this embodiment, from the power-on to the timer 15 for a certain period T as shown in FIG.
However, the inverted signal of the timer output, that is, the "L" signal is the AND circuit 2.
Since it is input to 0, the output of the AND circuit 20 becomes “L” as shown in FIG. 8D regardless of the inverted Q output of the flip-flop 18, and the light emitting diode LED of the display unit 1 is turned off. The flip-flop 18 is reset when the power is turned on, and its inverted Q output is set to "H" as shown in FIG. 8 (c).

If the discharge lamp 3 is normal, the voltage signal of the lamp voltage detector 19 exceeds the reference voltage Vref within a certain period T due to the increase in the output of the lighting circuit 9, and the output of the comparator 14 is shown in FIG. Set to "H" as shown. Therefore, the output of the AND circuit 17 rises to "H" and the flip-flop 1
8 is set and the inverted Q output is inverted to "L". Therefore, the timer output of the timer 15 becomes "
The output of the AND circuit 20 remains "L" even when it becomes L ", and the light-off state of the light emitting diode LED is maintained.

When the discharge lamp 3 is at the end of its life, FIG.
The voltage signal of the lamp voltage detector 19 does not exceed the reference voltage Vref of the comparator 14 during the constant time T when the timer output shown in (a) is "H", so that the timer output becomes "L" constant. After the lapse of the period T, the voltage signal of the lamp voltage detecting unit 19 exceeds the reference voltage Vref of the comparator 14, and the output of the comparator 14 is "H" as shown in FIG. 9B.
Even if this happens, the output of the AND circuit 17 is "L", the flip-flop 18 is not set, and its inverted Q output is not inverted to "L" as shown in FIG. 9C. . Therefore, the output of the AND circuit 20 is shown in FIG.
From the time when the timer output is inverted to "L" as shown in
Then, the light emitting diode LED of the display section 11 is turned on, and the user is informed that the discharge lamp 3 is at the end of its life and the replacement of the discharge lamp 3 is prompted.

If the comparator 14 is constructed as shown in FIG. 10 (a), the output can be made "H" while the voltage signal of the lamp voltage detector 19 is lower than the reference voltage Vref '. With the configuration shown in FIG. 10B, the voltage signal of the lamp voltage detection unit 19 proportional to the lamp voltage is equal to or higher than the reference voltage Vref ′ of the comparator 14b and equal to or lower than the reference voltage Vref of the comparator 14a. Only in the case of 1), "H" can be output from the AND circuit 21, and normality and abnormality of the lamp voltage can be detected within a range having upper and lower limits.

In the third embodiment, the lighting state of the discharge lamp 3 is detected by the lamp voltage, but it may be detected by the lamp current or the lamp power. (Embodiment 4) In this embodiment, as shown in FIG. 11, two left and right lamp bodies 12 are provided in which the lighting state of the discharge lamp 3 is provided as a headlamp.
The discharge state of the discharge lamps 3a and 3b mounted on a and 12b is to be detected, and the lighting state detection unit 10 of the present embodiment detects the light beams of the discharge lamps 3a and 3b, respectively. , 13b to convert into a voltage signal, the difference between the electric signals of both sensors 3a, 3b is taken out by a differential amplifier 22, and the level of the difference signal and a predetermined allowable value of the difference between the normal light fluxes are dealt with. The comparator 14 compares the reference voltage Vref with the reference voltage Vref. That is, when the level of the difference signal exceeds the reference voltage Vref, the output of the comparator 14 becomes "H", and the light emitting diode LED of the display unit 11
Is turned on to inform the user that one of the discharge lamps 3a and 3b has reached the end of its life.

As described above, in this embodiment, it is possible to detect when one of the discharge lamps reaches the end of its life due to the variation in the discharge lamps 3a and 3b of the headlight, and to avoid the one-eye traveling in the vehicle in advance. can do. Further, it can be notified even when the running safety cannot be ensured due to the imbalance of the light amounts of the left and right discharge lamps 3a and 3b, and it functions as an effective safety protection means in the vehicle.

[0035]

According to the invention of claim 1, there is provided a discharge lamp lighting device comprising a power supply and a lighting circuit for excessively supplying electric power to the discharge lamp when the lamp voltage is lower than a rated value.
After the power is turned on, a lighting state detecting means for detecting an element indicating the lighting state of the discharge lamp within a predetermined time, and means for notifying when the detection amount of the lighting state detecting means is out of a predetermined value, are provided. The life of the discharge lamp can be detected by detecting the lighting state of the discharge lamp after the power is turned on, and the user can promptly take measures such as replacement of the discharge lamp to notify the user of the detection of the life. , Therefore, even when it is used to light a vehicle headlight using a discharge lamp,
There is an effect that it becomes possible to prevent troubles such as the discharge lamp suddenly turning off due to the end of its life.

According to a second aspect of the present invention, in the first aspect of the invention, the element indicating the output state of the discharge lamp is detected, and if the detected value is outside the predetermined value, it is notified by a display. It has the same effect as. Claim 3
In the invention of claim 1, the time until the discharge lamp starts discharging after the power is turned on is detected as the above element, and if the detected time is out of a predetermined value, it is indicated by a display. It is possible to detect the life of the discharge lamp before the start of lighting, and prompt the user to take measures such as prompt replacement of the discharge lamp. Can be improved. According to the invention of claim 4, the life of the discharge lamp can be detected in a short time immediately after the discharge lamp is started and lit, so that the user is urged to take an action such as prompt replacement of the discharge lamp, and There is an effect that it is possible to improve safety when the headlight is used for lighting.

According to a fourth aspect of the invention, in the invention of the first aspect, any one of the luminous flux of the discharge lamp, the lamp voltage, the lamp current, and the lamp power is used as the element, and the discharge lamp starts to discharge the element. Detected after a certain time from
If the detected value is out of the specified range, it will be notified by the display, so it is possible to detect the life of the discharge lamp in a short time immediately after the discharge lamp is started and lit. This has the effect of prompting the user to improve the safety when using the headlight of a vehicle for lighting.

According to a fifth aspect of the present invention, in the illumination apparatus having a plurality of HID lamps as discharge lamps according to the first aspect of the present invention, each discharge lamp emits a luminous flux after a predetermined time from the start of discharge. It detects each discharge lamp and informs the display that the difference in luminous flux is larger than a predetermined value, so it is possible to detect the life of the discharge lamp in a short time immediately after the discharge lamp is started and lit. This has the effect of prompting the user to take measures such as replacing the lamp, improving the safety when using it to turn on the headlights of a car, and moreover, it is possible to easily detect the life of multiple discharge lamps. .

[Brief description of drawings]

FIG. 1 is a circuit diagram of a first embodiment of the present invention.

FIG. 2 is a timing chart for explaining the above operation.

FIG. 3 is a luminous flux change characteristic diagram of the discharge lamp for explaining the above operation.

FIG. 4 is a circuit diagram of a second embodiment of the present invention.

FIG. 5 is a timing chart for explaining the operation of the above normal discharge lamp.

FIG. 6 is a timing chart for explaining the operation of the discharge lamp at the end of its life.

FIG. 7 is a circuit diagram of a third embodiment of the present invention.

FIG. 8 is a timing chart for explaining the operation of the above normal discharge lamp.

FIG. 9 is a timing chart for explaining the operation of the discharge lamp at the end of its life.

FIG. 10 (a) is another circuit example of the above comparator.
(B) is another circuit example of the comparator.

FIG. 11 is a circuit diagram of a fourth embodiment of the present invention.

FIG. 12 is a circuit diagram of a conventional example.

FIG. 13 is a timing chart for explaining the operation of the above inverter circuit.

FIG. 14 is an explanatory diagram of the PWM operation of the above.

FIG. 15 is an explanatory diagram of increasing luminous flux of the discharge lamp of the above.

[Explanation of symbols]

 3 discharge lamp 4 igniter 9 lighting circuit 10 lighting state detection unit 11 display unit 13 optical sensor 14 comparator 15 timer 16 NAND circuit LED light emitting diode Vref reference voltage SW power switch.

Claims (5)

[Claims] 1. A discharge lamp lighting device comprising: a power supply; and a lighting circuit for making the output supplied to the discharge lamp excessive when the lamp voltage is lower than a rated value. A discharge lamp lighting device, comprising: a lighting state detecting unit that detects an element indicating a lighting state; and a unit that notifies when a detection amount of the lighting state detecting unit is out of a predetermined value. 2. The discharge lamp lighting device according to claim 1, wherein an element indicating an output state of the discharge lamp is detected, and if the detected value is out of a predetermined value, a notification is given by a display. 3. The method according to claim 1, wherein the time until the discharge lamp starts to discharge after the power is turned on is detected as the element, and if the detected time is out of a predetermined value, it is indicated by a display. Discharge lamp lighting device. 4. A luminous flux of a discharge lamp, a lamp voltage, a lamp current, or a lamp power is used as the above-mentioned element, and this element is detected after a fixed time has elapsed after the discharge lamp starts to discharge, and the detected value is The discharge lamp lighting device according to claim 1, wherein if it is out of a predetermined value, a notification is given by a display. 5. A lighting fixture equipped with a plurality of HID lamps as discharge lamps, wherein each discharge lamp detects a luminous flux after a predetermined time has elapsed from the start of discharge, and the difference in luminous flux is The discharge lamp lighting device according to claim 1, wherein the display notifies that the value is larger than a predetermined value.