U.S. patent application number 09/891353 was filed with the patent office on 2001-11-29 for electric-discharge lamp control apparatus and electric-discharge lamp control method.
This patent application is currently assigned to MITSUBISHI DENKI KABUSHIKI KAISHA. Invention is credited to Kinoshita, Hidehiko.
Application Number | 20010045804 09/891353 |
Document ID | / |
Family ID | 14237194 |
Filed Date | 2001-11-29 |
United States Patent
Application |
20010045804 |
Kind Code |
A1 |
Kinoshita, Hidehiko |
November 29, 2001 |
Electric-discharge lamp control apparatus and electric-discharge
lamp control method
Abstract
A flickering number in an electric-discharge lamp 7 is counted
in a flickering number counting unit 23a, a flickering number in an
electric-discharge lamp 8 is counted in a flickering number
counting unit 23b, and the lighting of the electric-discharge lamp
7 or 8 is inhibited by a lamp-lighting inhibiting unit 24a or 24b
in cases where the flickering number in the electric-discharge lamp
7 or 8 exceeds a regular number.
Inventors: |
Kinoshita, Hidehiko; (Tokyo,
JP) |
Correspondence
Address: |
SUGHRUE, MION, ZINN, MACPEAK & SEAS
2100 Pennsylvania Avenue, N.W.
Washington
DC
20037
US
|
Assignee: |
MITSUBISHI DENKI KABUSHIKI
KAISHA
|
Family ID: |
14237194 |
Appl. No.: |
09/891353 |
Filed: |
June 27, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09891353 |
Jun 27, 2001 |
|
|
|
PCT/JP99/06119 |
Feb 11, 1999 |
|
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Current U.S.
Class: |
315/291 ;
315/219; 315/250 |
Current CPC
Class: |
Y02B 20/00 20130101;
H05B 41/2925 20130101; Y10S 315/07 20130101; H05B 47/24
20200101 |
Class at
Publication: |
315/291 ;
315/250; 315/219 |
International
Class: |
H05B 037/02 |
Claims
What is claimed is:
1. An electric-discharge lamp control apparatus, comprising:
lamp-lighting control means for monitoring a voltage applied to a
stabilizer of an electric-discharge lamp, putting out the
electric-discharge lamp in a case where the voltage is out of an
allowed voltage range and again lighting the electric-discharge
lamp in a case where the voltage is returned within the allowed
voltage range; counting means for counting a flickering number in
the electric-discharge lamp which flickers according to the control
of the lamp-lighting control means; and lamp-lighting inhibiting
means for inhibiting the lighting of the electric-discharge lamp in
a case where the flickering number counted by the counting means
exceeds a regular number.
2. An electric-discharge lamp control apparatus according to claim
1, wherein the lamp-lighting inhibiting means resets the flickering
number counted by the counting means each time a regular time
passes and inhibits the lighting of the electric-discharge lamp in
a case where the flickering number counted within the regular time
exceeds the regular number.
3. An electric-discharge lamp control apparatus according to claim
1, wherein the lamp-lighting inhibiting means inhibits the lighting
of the electric-discharge lamp in an only case where a flickering
time period determined by the light-out and the lighting of the
electric-discharge lamp is shorter than a regular time period.
4. An electric-discharge lamp control method, comprising the steps
of: monitoring a voltage applied to a stabilizer of an
electric-discharge lamp; putting out the electric-discharge lamp in
a case where the voltage is out of an allowed voltage range; again
lighting the electric-discharge lamp in a case where the voltage is
returned within the allowed voltage range; counting a flickering
number in the electric-discharge lamp; and inhibiting the lighting
of the electric-discharge lamp in a case where the flickering
number exceeds a regular number.
5. An electric-discharge lamp control method according to claim 4,
wherein the step of inhibiting the lighting of the
electric-discharge lamp includes the steps of: resetting the
flickering number each time a regular time passes; and inhibiting
the lighting of the electric-discharge lamp in a case where the
flickering number counted within the regular time exceeds the
regular number.
6. An electric-discharge lamp control method according to claim 4,
wherein the step of inhibiting the lighting of the
electric-discharge lamp includes the step of: inhibiting the
lighting of the electric-discharge lamp in an only case where a
flickering time period determined by the light-out and the lighting
of the electric-discharge lamp is shorter than a regular time
period.
Description
CROSS-REFERENCE TO The RELATED APPLICATION
[0001] This application is a continuation of International
Application No. PCT/JP99/06119, whose International filing date is
Nov. 2, 1999, the disclosures of which Application are incorporated
by reference herein, and which International Application was not
published in English.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an electric-discharge lamp
control apparatus and an electric-discharge lamp control method in
which the electric-discharge lamp is prevented from flickering.
[0004] 2. Description of Related Art
[0005] In a conventional electric-discharge lamp control apparatus,
a voltage applied to an electric-discharge lamp is monitored in an
abnormal state judging circuit, and the applied voltage is compared
with various reference voltages.
[0006] Thereafter, when an abnormal state is detected according to
a comparison result in the abnormal state judging circuit of the
conventional electric-discharge lamp control apparatus, the
electric-discharge lamp is put out by the conventional
electric-discharge lamp control apparatus.
[0007] The technique in the conventional electric-discharge lamp
control apparatus is disclosed in the Published Unexamined Japanese
Patent Application No. H8-106986 (1996).
[0008] Because the conventional electric-discharge lamp control
apparatus has the above-described configuration, a life end of the
electric-discharge lamp can be detected. However, when an abnormal
state such as the flickering of the electric-discharge lamp occurs
because an abnormal circumstance occurs in a peripheral circuit of
the electric-discharge lamp, the lighting of the electric-discharge
lamp cannot be inhibited. Therefore, there is a problem that the
life of the electric-discharge lamp cannot be prevented from being
shortened.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide, with due
consideration to the drawbacks of the conventional
electric-discharge lamp control apparatus and the conventional
electric-discharge lamp control method, an electric-discharge lamp
control apparatus and an electric-discharge lamp control method in
which the life of an electric-discharge lamp is prevented from
being shortened according to the flickering of the lamp.
[0010] An electric-discharge lamp control apparatus according to
the present invention comprises counting means for counting a
flickering number in an electric-discharge lamp which flickers
according to the control of lamp-lighting control means, and
lamp-lighting inhibiting means for inhibiting the lighting of the
electric-discharge lamp in a case where the flickering number
counted by the counting means exceeds a regular number.
[0011] Accordingly, the life of the electric-discharge lamp can be
prevented from being shortened.
[0012] In the electric-discharge lamp control apparatus according
to the present invention, the flickering number counted by the
counting means is reset each time a regular time passes, and the
lighting of the electric-discharge lamp is inhibited in a case
where the flickering number counted within the regular time exceeds
the regular number.
[0013] Accordingly, in cases where the electric-discharge lamp
flickers according to the will of a user, the lighting of the
electric-discharge lamp is not inhibited. However, the lighting of
the electric-discharge lamp can be inhibited in an only case where
a failure occurs.
[0014] In the electric-discharge lamp control apparatus according
to the present invention, the lighting of the electric-discharge
lamp is inhibited in an only case where a flickering time period
determined by the light-out and the lighting of the
electric-discharge lamp is shorter than a regular time period.
[0015] Accordingly, in cases where the electric-discharge lamp
flickers according to the will of a user, the lighting of the
electric-discharge lamp is not inhibited. However, the lighting of
the electric-discharge lamp can be inhibited in an only case where
a failure occurs.
[0016] An electric-discharge lamp control method according to the
present invention comprises the steps of counting a flickering
number in an electric-discharge lamp, and inhibiting the lighting
of the electric-discharge lamp in a case where the flickering
number exceeds a regular number.
[0017] Accordingly, the life of the electric-discharge lamp can be
prevented from being shortened.
[0018] In the electric-discharge lamp control method according to
the present invention, the flickering number is reset each time a
regular time passes, and the lighting of the electric-discharge
lamp is inhibited in a case where the flickering number counted
within the regular time exceeds the regular number.
[0019] Accordingly, in cases where the electric-discharge lamp
flickers according to the will of a user, the lighting of the
electric-discharge lamp is not inhibited. However, the lighting of
the electric-discharge lamp can be inhibited in an only case where
a failure occurs.
[0020] In the electric-discharge lamp control method according to
the present invention, the lighting of the electric-discharge lamp
is inhibited in an only case where a flickering time period
determined by the light-out and the lighting of the
electric-discharge lamp is shorter than a regular time period.
[0021] Accordingly, in cases where the electric-discharge lamp
flickers according to the will of a user, the lighting of the
electric-discharge lamp is not inhibited. However, the lighting of
the electric-discharge lamp can be inhibited in an only case where
a failure occurs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a circuit diagram of a headlight of a vehicle, to
which an electric-discharge lamp control apparatus is applied,
according to a first embodiment of the present invention.
[0023] FIG. 2 is a block diagram of the electric-discharge lamp
control apparatus according to the first embodiment of the present
invention.
[0024] FIG. 3 is a flow chart of an electric-discharge lamp control
method according to the first embodiment of the present
invention.
[0025] FIG. 4 is a circuit diagram describing the flow of an
electric current in case of failure of an electric-discharge
lamp.
[0026] FIG. 5 is a circuit diagram describing a voltage applied to
a stabilizer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] The invention will now be described with reference to the
accompanying drawings.
[0028] Embodiment 1
[0029] FIG. 1 is a circuit diagram of a headlight of a vehicle, to
which an electric-discharge lamp control apparatus is applied,
according to a first embodiment of the present invention. In FIG.
1, 1 indicates a battery from which a direct current of 12 V is
output. 2 indicates a change-over switch for putting on or out a
headlight. The headlight comprises an electric-discharge lamp 7,
another electric-discharge lamp 8, a halogen lamp 9 and another
halogen lamp 10. 3 indicates a fuse. 4 indicates another fuse. 5
indicates a stabilizer of the electric-discharge lamp 7. 6
indicates a stabilizer of the electric-discharge lamp 8. 7
indicates one electric-discharge lamp (shown by HID). 8 indicates
the other electric-discharge lamp (shown by HID). 9 indicates one
halogen lamp. 10 indicates the other halogen lamp. 11 indicates a
selector switch for selecting a low beam (the electric-discharge
lamps 7 and 8 are put on, and the halogen lamps 9 and 10 are put
out) or a high beam (the electric-discharge lamps 7 and 8 and the
halogen lamps 9 and 10 are put on).
[0030] FIG. 2 is a block diagram of the electric-discharge lamp
control apparatus according to the first embodiment of the present
invention. In FIG. 2, 21a indicates a voltage inputting unit for
receiving a voltage to be applied to the stabilizer 5 of the
electric-discharge lamp 7. 21b indicates a voltage inputting unit
for receiving a voltage to be applied to the stabilizer 6 of the
electric-discharge lamp 8. 22a indicates a lamp-lighting control
unit (or a lamp-lighting control means) for monitoring a voltage
received in the voltage inputting unit 21a, outputting a light-out
instruction to put out the electric-discharge lamp 7, in cases
where the voltage is out of an allowed voltage range, and
outputting a re-lighting instruction to again put on the
electric-discharge lamp 7 in cases where the voltage returns within
the allowed voltage range. 22b indicates a lamp-lighting control
unit (or a lamp-lighting control means) for monitoring a voltage
received in the voltage inputting unit 21b, outputting a light-out
instruction to put out the electric-discharge lamp 8, in cases
where the voltage is out of the allowed voltage range, and
outputting a re-lighting instruction to again put on the
electric-discharge lamp 8 in cases where the voltage returns within
the allowed voltage range. 23a indicates a flickering number
counting unit (or a counting means) for counting the number of
flicker operations (called a flickering number) performed in the
electric-discharge lamp 7. 23b indicates a flickering number
counting unit (or a counting means) for counting the number of
flicker operations (called a flickering number) performed in the
electric-discharge lamp 8. 24a indicates a lamp-lighting inhibiting
unit (or a lamp-lighting inhibiting means) for inhibiting the
lighting of the electric-discharge lamp 7 in cases where the
flickering number counted in the flickering number counting unit
23a exceeds a regular number. 24b indicates a lamp-lighting
inhibiting unit (or a lamp-lighting inhibiting means) for
inhibiting the lighting of the electric-discharge lamp 8 in cases
where the flickering number counted in the flickering number
counting unit 23b exceeds the regular number. 25a indicates an
outputting unit for putting out or again putting on the
electric-discharge lamp 7 according to the instruction output from
the lamp-lighting control unit 22a. 25b indicates an outputting
unit for putting out or again putting on the electric-discharge
lamp 8 according to the instruction output from the lamp-lighting
control unit 22b.
[0031] FIG. 3 is a flow chart of an electric-discharge lamp control
method according to the first embodiment of the present
invention.
[0032] Next, an operation is described.
[0033] Initially, when a user turns on the change-over switch 2 of
the headlight, a battery voltage of 12 V is applied to the
stabilizers 5 and 6 of the electric-discharge lamps 7 and 8.
Therefore, a light is put to each of the electric-discharge lamps 7
and 8. In this case, when the selector switch 11 is set to the
"off" state, no electric current flows through the halogen lamp 9
or 10. Therefore, no light is put to the halogen lamp 9 or 10. In
contrast, when the selector switch 11 is set to the "on" state, a
light is put to each of the halogen lamps 9 and 10.
[0034] However, in cases where a failure such as the burn-out of
the fuse 4 occurs in the headlight when the electric-discharge
lamps 7 and 8 are set in a light-on state, as shown in FIG. 4, a
series circuit composed of the halogen lamps 9 and 10 and the
stabilizer 6 is formed (in this case, for convenience of
explanation, it is assumed that the selector switch 11 is set in
the "off" state). Therefore, the battery voltage of 12 V to be
applied to the stabilizer 6 is divided by the halogen lamps 9 and
10, and the voltage actually applied to the stabilizer 6 is lowered
to almost 2 V.
[0035] In cases where an allowed voltage range of the stabilizer 6
is, for example, set in a range from 10 to 14 V, the lamp-lighting
control unit 22b detects that the voltage applied to the stabilizer
6 is out of the allowed voltage range, and a light-out instruction
is output from the lamp-lighting control unit 22b to the outputting
unit 25b to put out the electric-discharge lamp 8.
[0036] Therefore, the electric-discharge lamp 8 is put out. In this
case, the voltage applied to the stabilizer 6 is returned to 12 V
because of the putting-out of the electric-discharge lamp 8.
Therefore, the lamp-lighting control unit 22b detects that the
voltage applied to the stabilizer 6 is returned within the allowed
voltage range, and a re-lighting instruction is output from the
lamp-lighting control unit 22b to the outputting unit 25b to put on
the electric-discharge lamp 8.
[0037] As a result, the electric-discharge lamp 8 is again put on.
However, as shown in FIG. 5, because the voltage applied to the
stabilizer 6 is alternatively set to 2 V and 12 V, the
electric-discharge lamp 8 repeatedly flickers. The flickering of
the electric-discharge lamp 8 adversely influences on the running
of the vehicle, and there is a problem that the life of the
electric-discharge lamp 8 is shortened when the flickering of the
electric-discharge lamp 8 is continued.
[0038] To avoid this problem in the first embodiment, the change of
the instruction output from the electric-discharge lamp 8 is
monitored to supervise the flickering of the electric-discharge
lamp 8, and the electric-discharge lamp 8 is inhibited from being
put on when an abnormal flickering of the electric-discharge lamp 8
is detected.
[0039] More precisely, as shown in FIG. 3, in cases where the
instruction previously output from the lamp-lighting control unit
22b denotes a light-out instruction (step STI), when a re-lighting
instruction is currently output from the lamp-lighting control unit
22b (step ST2), a flickering number is incremented in the
flickering number counting unit 23b (step ST4).
[0040] Also, in cases where the instruction previously output from
the lamp-lighting control unit 22b denotes a re-lighting
instruction (step ST1), when a light-out instruction is currently
output from the lamp-lighting control unit 22b (step ST3), the
flickering number is incremented in the flickering number counting
unit 23b in the same manner (step ST4).
[0041] Thereafter, when the flickering number counted in the
flickering number counting unit 23b exceeds a regular number (step
ST5), a lamp-lighting inhibition instruction is output from the
lamp-lighting inhibiting unit 24b to the outputting unit 25b to
inhibit the electric-discharge lamp 8 from being put on (step
ST6).
[0042] Therefore, unless the lamp-lighting inhibition instruction
for the electric-discharge lamp 8 is canceled, the
electric-discharge lamp 8 is not again put on. Therefore, the
flickering of the electric-discharge lamp 8 can be avoided.
[0043] Here, even though the headlight is continuously used in the
normal state, there is a case where the flickering number counted
in the flickering number counting unit 23b is accumulatively
increased and reaches the regular number. To avoid this problem,
the number counted in the flickering number counting unit 23b is
periodically reset to zero in the lamp-lighting inhibiting unit
24b. However, because the flickering number is incremented when the
user operates the change-over switch 2, there is possibility that
the lamp-lighting inhibition instruction is output according to the
operation of the user.
[0044] Therefore, it is desired that a reset time period of the
flickering number and the regular number are set to a combination
of values which is not obtained in the normal use state. For
example, a reset time period of the flickering number is set to 1
minute, and the regular number is set to about 20.
[0045] As is apparently described above, in the first embodiment,
the number of flickering operations (that is, the flickering
number) in the electric-discharge lamp 7 or 8 is counted, and the
lighting of the electric-discharge lamp is inhibited when the
flickering number exceeds the regular number. Therefore, the life
of the electric-discharge lamp can be prevented from being
shortened according to the flickering of the lamp.
[0046] Here, output states of the lamp-lighting control units 22a
and 22b in a microcomputer are monitored by the flickering number
counting units 23a and 23b and the lamp-lighting inhibiting units
24a and 24b, and the lighting of the electric-discharge lamp 7 or 8
is inhibited. Therefore, the inhibition of the lighting of the
electric-discharge lamp 7 or 8 according to the first embodiment
differs from that which is performed by monitoring voltages applied
to the stabilizers 5 and 6.
[0047] More precisely, in cases where voltages applied to the
stabilizers 5 and 6 are monitored to judge whether or not the
electric-discharge lamp 7 or 8 flickers, when the voltage is
considerably changed in a moment because of noise, there is
probability that it is erroneously judged that the
electric-discharge lamp 7 or 8 flickers. However, in cases where
output states of the lamp-lighting control units 22a and 22b in a
microcomputer are monitored according to the first embodiment, the
judgment can be accurately performed without receiving the
influence of the noise.
[0048] Embodiment 2
[0049] In the first embodiment, when the flickering number exceeds
the regular number, the lighting of the electric-discharge lamp 7
or 8 is inhibited. However, in a second embodiment, even though the
flickering number exceeds the regular number, it is preferred that
the lighting of the electric-discharge lamp 7 or 8 is inhibited on
condition that the flickering time period determined by the
light-out of the electric-discharge lamp 7 or 8 and the re-lighting
of the electric-discharge lamp 7 or 8 is shorter than a regular
time period.
[0050] Accordingly, a problem that the lighting of the
electric-discharge lamp 7 or 8 in the normal use state based on the
normal use of the user is undesirably inhibited can be
prevented.
[0051] For example, the lighting of the electric-discharge lamp 7
or 8 is inhibited only when a flickering frequency corresponding to
the flickering time period exceeds 1/3 Hz.
[0052] Embodiment 3
[0053] In the first and second embodiments, coils of the halogen
lamps 9 and 10 compose a part of the serial circuit. However, in a
third embodiment, in cases where the electric-discharge lamps 7 and
8 are used in a two-lamp type headlight (one headlight is arranged
on each of right and left sides), an optical axis of the lamp
arranged on one side is moved up and down by a motor so as to
alternately select a high beam and a low beam, and a solenoid of
the motor is serially connected with the halogen lamps 9 and 10 of
the first or second embodiment so as to function as a load having a
serial resistance component. In this case, though the
electric-discharge lamps 7 and 8 flicker, the flickering of the
electric-discharge lamps 7 and 8 can be inhibited in the same
manner as in the first and second embodiments.
[0054] As is described above, the electric-discharge lamp control
apparatus and the electric-discharge lamp control method are
generally appropriate to a voltage monitoring system in which a
voltage applied to a stabilizer of an electric-discharge lamp is
monitored, the electric-discharge lamp is put out when the voltage
is out of an allowed voltage range, and the electric-discharge lamp
is again put on when the voltage is returned within the allowed
voltage range. In particular, the apparatus and the method are
appropriate to a voltage monitoring system in which the lighting of
the electric-discharge lamp is inhibited to prevent the life of the
electric-discharge lamp from being shortened when an abnormal
circumstance occurs and the electric-discharge lamp frequently
flickers.
* * * * *