JP5599655B2 - Lamp disconnection detector - Google Patents

Description

  The present invention relates to a lamp breakage detection device that detects breakage of various lamps such as indicator lights and taillights of a direction indicator provided in a vehicle.

  2. Description of the Related Art Conventionally, a vehicle such as an automobile is provided with a lamp disconnection detection device that detects disconnection of an indicator lamp (blinker lamp) or a tail lamp (tail lamp) of a direction indicator. Such a lamp breakage detection device measures the current value flowing through the lamp when the lamp is lit, and compares it with a reference current value set in advance at the time of manufacture, and the difference between the measured current value and the reference current value. When the value exceeds a predetermined disconnection determination reference value, it is determined that the lamp is disconnected, and an alarm (for example, flashing in a short cycle (high flasher) or the like) is performed as necessary.

  In general, lamps such as those described above can be used even under normal conditions such as disconnection due to changes in various conditions such as the outside air temperature, self-heating temperature, or the degree of lamp deterioration (ie, current value fluctuation conditions). It is known that the value of the current flowing through the lamp changes within a predetermined range (that is, a normal range). And if the current value which flows into a lamp | ramp changes with the change of this electric current value fluctuation | variation condition, in the lamp | ramp disconnection detection apparatus mentioned above, although the lamp | ramp is not disconnected, the said difference value exceeds the said disconnection determination reference value. There is a problem that it is erroneously determined that the lamp is disconnected. And the technique which solves such a problem is proposed by patent document 1, etc., for example.

  The lamp breakage detection device disclosed in Patent Document 1 includes a current sensor for measuring a current flowing through each lamp, and a controller to which the current sensor is connected. The controller includes a nonvolatile memory in which a reference current value is stored. Then, the controller measures the value of the current flowing through the lamp based on the output of the current sensor and compares it with the reference current value stored in the nonvolatile memory to obtain the difference value. When the difference value exceeds the disconnection determination reference value, it is determined that the lamp is disconnected and an alarm is issued, and the difference value is not 0 and does not exceed the disconnection determination reference value (that is, When the current value fluctuation condition changes, the current value flowing through the lamp has changed to such an extent that it is not determined to be disconnected), and the non-volatile memory is overwritten with the measured current value as a new reference current value. Used for disconnection detection. In this way, the lamp breakage detecting device can correctly detect the lamp breakage by updating the reference current value according to the change in the current value fluctuation condition.

JP 2008-145260 A

  However, in the lamp disconnection detecting device, when the current value flowing through the lamp gradually changes as the current value variation condition changes, the reference current value stored in the nonvolatile memory is sequentially updated, and then the lamp is disconnected. When the determination is made, the update of the reference current value is stopped. At this time, the nonvolatile memory stores the reference current value corresponding to the current value fluctuation condition at the time of lamp disconnection determination. If the current value fluctuation condition of the lamp is significantly different from the current value fluctuation condition at the first lighting after lamp replacement, the difference value between the current value measured at the first lighting and the reference current value stored in the nonvolatile memory is disconnected. In spite of the fact that the judgment reference value was exceeded and the lamp was replaced with a normal lamp without disconnection, there was a problem that the disconnection of the lamp was erroneously detected immediately after that. Further, in order to avoid such erroneous detection of lamp breakage, a configuration in which the reference current value is reset when replacing the lamp is conceivable. To that end, in order to reset the reference current value in the lamp breakage detection device, Since there is another problem that the manufacturing cost will increase, and it will be necessary to set the reference current value when replacing the lamp, it will be complicated to replace the lamp. There was also a problem.

  The present invention aims to solve the above problems. That is, an object of the present invention is to provide an inexpensive lamp disconnection detection device that can prevent erroneous detection of lamp disconnection that may occur after lamp replacement.

In order to achieve the above object, according to the first aspect of the present invention, as shown in the basic configuration diagram of FIG. 1, the current value measurement for measuring the current value flowing through the lamp when the lamp provided in the vehicle is turned on. means 61a, in accordance with the measurement of the current value by the current value measuring unit 61a, a lamp disconnection detecting with a disconnection detecting means 61b for detecting the disconnection of the lamp based on the current value and the standards current value, the in the device, a normal range storage means 64 for storing a normal range of current flowing to the lamp, only for the current value measured at the time of the first lighting of the lamp after power-on of the vehicle by the current value measuring unit 61a , and an initial current value determination unit 61c determines whether the current value is included in the normal range, and the disconnection detecting section 61b is the first current value The disconnection of the lamp is detected by using, as the reference current value, the current value measured when the lamp is determined to be included in the normal range by the fixing means 61c. This is a lamp breakage detection device.

  In the invention described in claim 2, in the invention described in claim 1, as shown in the basic configuration diagram of FIG. 1, the initial current value determination unit 61c measures the lamp when it is turned on for the first time. When it is determined that the current value is not included in the normal range, lamp abnormality notification means 61d for notifying that an abnormality has occurred in the lamp is provided.

  According to the first aspect of the present invention, the initial current value determining means 61c includes whether the current value flowing through the lamp measured when the lamp is turned on for the first time after turning on the vehicle is included in the normal range. Determine whether or not. Then, the disconnection detection means 61b detects the disconnection of the lamp using the current value determined to be included in the normal range as a reference current value.

  According to the invention described in claim 2, when the lamp abnormality notification means 61d determines that the value of the current flowing through the lamp measured at the time of the initial lighting of the lamp is not included in the normal range, Notifies that an error has occurred in the lamp.

According to the first aspect of the present invention, it is determined whether or not the current value is included in the normal range of only the current value flowing through the lamp measured when the lamp is first turned on after the vehicle is turned on. Since the disconnection of the lamp is detected using the current value determined to be included in the normal range as a reference current value, it is used for disconnection detection every time the vehicle is turned on. The reference current value is reset within the normal range determined in consideration of the change in the current value fluctuation condition. Therefore, the lamp breaks using the reference current value corresponding to the current value fluctuation condition when the lamp is turned on for the first time. Even if the current value fluctuation condition at the time of lamp breakage detection is significantly different from the current value fluctuation condition at the first lighting after lamp replacement, it is possible to detect the lamp breakage incorrectly. . Therefore, it is possible to prevent erroneous detection of lamp breakage that may occur after lamp replacement. Further, since it is not necessary to provide a function for resetting the reference current value, it can be configured at low cost.

  Further, since the disconnection is detected using the reference current value corresponding to the current value fluctuation condition at the first lighting after the vehicle is turned on, the current flowing through the lamp at the beginning of the operation of the lamp disconnection detecting device Therefore, even if the current value fluctuation condition such as the outside temperature changes after that, the difference value between the current value flowing through the lamp and the reference current value becomes the disconnection judgment reference value. The value of the current flowing through the lamp hardly changes to the extent that it exceeds the limit, and it is possible to prevent erroneous detection of lamp disconnection due to changes in the current value fluctuation condition after the vehicle power is turned on. Can be increased. Also, even if the difference value exceeds the disconnection judgment reference value due to changes in the current value fluctuation condition, by turning the vehicle power off and then on again, the current value fluctuation condition at that time Since the reference current value corresponding to is reset, the disconnection of the lamp can be detected correctly, and unnecessary lamp replacement or the like can be avoided.

  According to the invention described in claim 2, when it is determined that the value of the current flowing through the lamp measured when the lamp is turned on for the first time is not included in the normal range, an abnormality has occurred in the lamp. If the value of the current flowing through the lamp is not included in the normal range, for example, a non-standard lamp that carries a large current may be installed incorrectly, or a fault such as a short circuit may have occurred. It is conceivable that the vehicle is in an abnormal state that may cause an accident. By notifying such an abnormal state, the accident can be prevented in advance.

It is a figure which shows the basic composition of the lamp disconnection detection apparatus of this invention. It is a figure which shows schematic structure of the direction indicator which is one Embodiment of the lamp disconnection detection apparatus of this invention. It is a figure which shows schematic structure of the microcomputer with which the control part of the direction indicator of FIG. 2 is provided. It is a flowchart which shows an example of the lamp disconnection detection process which concerns on this invention in the control part (CPU) of the direction indicator of FIG.

  Hereinafter, a direction indicator as an embodiment of a lamp breakage detection apparatus of the present invention will be described with reference to FIGS.

  As is well known, the direction indicator 1 includes indicator lights (also referred to as turn signal lamps) provided at four corners and side surfaces of the vehicle body, and indicates the traveling direction of the vehicle around by blinking the indicator lights. It is a device to do. As shown in FIG. 1, the direction indicator 1 includes an indicator lamp unit 10 as a lamp, a circuit opening / closing unit 20, a current sensor 30, and a control unit 40.

  The indicator lamp unit 10 includes a plurality of light emitting diodes (LEDs) 11a to 11n, and is disposed, for example, at a corner on the right rear side of the vehicle. The plurality of LEDs 11a to 11n are connected to each other in parallel, and each anode terminal (positive electrode side terminal) is connected to the power supply VCC via a current sensor 30 and a circuit opening / closing unit 20 which will be described later. Each cathode terminal (negative electrode side terminal) is connected to the chassis (that is, the ground GND).

  In the present embodiment, the indicator lamp unit 10 is composed of ten LEDs 11. The current value flowing through one LED 11 is 10 mA as a standard, and fluctuates in a range from a minimum of 8 mA to a maximum of 12 mA depending on a current value fluctuation condition such as an outside air temperature, a self-heating temperature during lighting, or aged deterioration. That is, the value of the current flowing through the indicator lamp unit 10 is 100 mA as a standard, and fluctuates in a range of 80 mA to 120 mA (that is, a normal range). In addition, since the current value flowing through one LED 11 is a minimum of 8 mA, when one of the plurality of LEDs 11 a to 11 n is disconnected when the current value flowing through the indicator light unit 10 changes, for example, exceeding 7 mA, Is determined. In addition to the LED, the indicator lamp unit 10 may be composed of a light source such as a halogen lamp, for example, and the number thereof is appropriately determined according to the configuration of the direction indicator 1 and the like.

  The circuit opening / closing unit 20 is configured by, for example, a well-known relay or MOSFET, and is a part that functions as a switch that opens and closes in response to an input opening / closing signal. The circuit opening / closing unit 20 is inserted in series (that is, connected in series) to a line connecting the power supply VCC and the indicator lamp unit 10 (hereinafter referred to as “power supply side line L”), and is closed from the control unit 40 described later. A signal or an open signal is input. The circuit opening / closing unit 20 opens or closes according to the opening / closing signal, thereby electrically connecting or disconnecting the power supply VCC and the indicator lamp unit 10 to supply or cut off the current to the indicator lamp unit 10.

  The current sensor 30 includes, for example, a fixed resistor inserted in series with the power supply side line L, and an operational amplifier that amplifies and outputs a potential difference between both ends of the fixed resistor. This is a part that functions as a sensor that outputs a voltage corresponding to the magnitude of the current flowing through L (that is, the indicator lamp unit 10). The output of the current sensor 30 is connected to a control unit 40 described later. In addition to the above, the current sensor 30 is arranged in the vicinity of the power supply side line L, and includes a Hall element that detects a magnetic field around the current sensor 30. Any structure can be used as long as it can be used for measurement.

  The control unit 40 is a part that controls the entire operation of the direction indicator 1, and is configured by a known microcomputer (MPU) or the like. As shown in FIG. 3, the MPU 60 provided in the control unit 40 includes (i) a central processing unit (CPU) 61 that performs various processes and controls in accordance with a predetermined program, and (ii) programs and various programs for the CPU 61. ROM 62 which is a read-only memory storing parameters, (iii) RAM 63 which is a readable / writable memory which stores various data and has an area necessary for the processing operation of CPU 61, and (iv) Necessary for processing operation of CPU 61 The interface unit (I / F) connected to the EEPROM 64, which is a memory having various storage areas and capable of holding various data stored even when power supply is cut off, and (v) peripheral functional units ) 65 etc.

  The ROM 62 stores in advance a control program that causes the CPU 61 to function as various means such as current value measuring means, disconnection detecting means, initial current value determining means, lamp abnormality notifying means, and indicator lamp blinking means. The CPU 61 functions as these means and the like by executing a control program stored in the ROM 62.

  The RAM 63 is provided with an area for storing a reference current value Is used for detecting disconnection. In the EEPROM 64, a normal range Rs and a disconnection determination reference value Cs are stored in advance.

  The normal range Rs is information indicating a range (that is, a normal range) that can be taken by the value of the current flowing through the indicator lamp unit 10 when the indicator lamp unit 10 described above is normal without a failure such as disconnection. For the normal range Rs, for example, a value indicating the range is set in consideration of the current value fluctuation condition that affects the current value flowing through the lamp, such as the outside air temperature, the self-heating temperature, or the degree of deterioration of the lamp. Yes.

  The disconnection determination reference value Cs is information indicating a reference value for determining that the indicator lamp unit 10 is disconnected, and is a difference value D between the current value I flowing through the indicator lamp unit 10 and the reference current value Is. It is an allowable upper limit value. That is, when the difference value D exceeds the disconnection determination reference value Cs, it is determined that the indicator lamp unit 10 is disconnected.

  In the present embodiment, 80 mA to 120 mA is set as the normal range Rs, and 7 mA is set as the disconnection determination reference value Cs. The EEPROM 64 corresponds to normal range storage means in the claims. Further, the normal range Rs and the disconnection determination reference value Cs may be stored in the ROM 62.

  The I / F 65 includes a communication function unit, a general-purpose output port, an analog-digital converter (ADC), and the like (not shown). The communication function unit is connected to an ECU (not shown) mounted on the vehicle, and receives a blinking start signal or a blinking stop signal transmitted from the ECU in response to an operation of a direction indicator switch (not shown) provided on the handle of the vehicle. To do. These signals received by the communication function unit are sent to the CPU 61. The general-purpose output port is connected to the circuit open / close unit 20, and the CPU 61 outputs an open / close signal to the circuit open / close unit 20 via the general-purpose output port. The ADC is connected to the current sensor 30, and a voltage corresponding to the magnitude of the current flowing through the indicator lamp unit 10 output by the current sensor 30 is input. The voltage input to the ADC is quantized and sent to the CPU 61. The CPU 61 applies the quantized voltage value to a voltage value-current value conversion table stored in advance in the ROM 62 or the EEPROM 64, and acquires (that is, measures) a current value flowing through the indicator lamp unit 10.

  When the control unit 40 (that is, the CPU 61) receives the blinking start signal from the ECU, the control unit 40 (that is, the CPU 61) alternately outputs a close signal and an open signal to the circuit opening / closing unit 20 at a predetermined blinking cycle, and then the blinking stop signal from the ECU. When the signal is received, the output of the closing signal is stopped and the opening signal is continuously output (that is, the indicator lamp blinking process). Moreover, the control part 40 measures the electric current value which flows into the indicator lamp unit 10 based on the voltage input into ADC.

  Next, an example of the process (lamp disconnection detection process) according to the present invention executed by the CPU 61 described above will be described below with reference to the flowchart shown in FIG.

  When the vehicle is powered on, the CPU 61 performs a predetermined initialization process such as outputting an open signal toward the circuit opening / closing unit 20, and then proceeds to step S110. In parallel with this, the CPU 61 executes the above-described indicator lamp blinking process.

  In step S110, the first lighting of the indicator light unit 10 is awaited. Specifically, after the vehicle is turned on, the first waiting signal output from the I / F 65 to the circuit opening / closing unit 20 is waited (N in S110), and when this closing signal is detected, the indicator light unit Assuming that 10 is turned on for the first time, the process proceeds to step S120 (Y in S110). If it demonstrates from another viewpoint, in the indicator flashing process currently performed in parallel with a lamp disconnection detection process, if the first flashing start signal is received from ECU after turning on the power of a vehicle, it will go to the circuit opening / closing part 20 The operation of alternately outputting the closing signal and the opening signal at a normal blinking cycle (for example, 1 second) is started, and in step S110, the closing signal output first is detected.

  In step S120, based on the voltage input to the ADC of the I / F 65, the current value I flowing through the indicator lamp unit 10 when the indicator lamp unit 10 is turned on (that is, when the closed signal is output) is measured. Then, the process proceeds to step S130.

  In step S130, it is determined whether or not the current value I measured in step S120 is included in the normal range Rs set in the EEPROM 64. When the current value I is included in the normal range Rs, Assuming that the indicator lamp unit 10 is normal, the process proceeds to step S140 (Y in S130), and when the current value I is not included in the normal range Rs, it is assumed that an abnormality has occurred in the indicator lamp unit 10. The process proceeds to step S200 (N in S130).

  In step S140, the current value I measured in step S120 is stored (stored) in the RAM 63 as the reference current value Is. Then, the process proceeds to step S150.

  In step S150, the lighting of the indicator light unit 10 is awaited. Specifically, it waits for a closing signal output from the I / F 65 toward the circuit opening / closing unit 20 (N in S150), and when this closing signal is detected, it proceeds to step S160 on the assumption that the indicator lamp unit 10 has been turned on. (Y in S150). That is, the closing signal output after the second time is detected.

  In step S160, based on the voltage input to the ADC of the I / F 65, the current value I flowing through the indicator lamp unit 10 when the indicator lamp unit 10 is turned on (that is, when the closed signal is output) is measured. Then, the process proceeds to step S170.

  In step S170, a difference value D (absolute value) between the current value I measured in step S160 and the reference current value Is stored in the RAM 63 in step S140 is calculated. Then, the process proceeds to step S180.

  In step S180, it is determined whether or not the difference value D calculated in step S170 exceeds the disconnection determination reference value Cs set in the EEPROM 64. When the difference value D exceeds the disconnection determination reference value Cs, It is determined that the indicator lamp unit 10 is disconnected, and the process proceeds to step S190 (Y in S180). When the difference value D is equal to or less than the disconnection determination reference value Cs, it is determined that the indicator lamp unit 10 is not disconnected. Then, the process returns to step S150 to wait for the indicator lamp unit 10 to be turned on again (N in S180).

  In step S190, the blinking cycle of the indicator light unit 10 is shortened. Specifically, the blinking period of the indicator lamp unit 10 in the indicator lamp blinking process being performed in parallel is changed to a blinking blinking period (for example, 0.5 seconds) shorter than the normal blinking period. Thereby, blinking of the indicator light unit 10 is accelerated. Then, the process returns to step S150.

  In step S200, a signal notifying the occurrence of abnormality of the indicator light unit 10 is output to the ECU. When the ECU receives a signal notifying the occurrence of the abnormality, the ECU turns on a warning lamp or the like provided in the instrument panel of the vehicle and notifies the occupant of the occurrence of the abnormality. Or if the abnormality which generate | occur | produced in the indicator light unit 10 is not connected with accidents, such as a vehicle fire, you may make it change a blinking period to a blinking period at the time of a disconnection in step S200 similarly to step S190. And the process of this flowchart is complete | finished.

  Steps S120 and S160 described above correspond to current value measurement means in the claims, steps S170 and 180 correspond to disconnection detection means in the claims, and step S130 corresponds to initial current value determination means in the claims. Step S200 corresponds to lamp abnormality notification means in the claims.

  Next, an example of the operation (action) of the direction indicator 1 according to the present invention will be described.

  When the direction indicator switch is operated for the first time after the vehicle is powered on, the direction indicator 1 normally flashes the indicator lamp unit 10 (indicator lamp flashing process). At the same time, the first lighting of the indicator lamp unit 10 is detected (Y in S110), and the current value I flowing through the indicator lamp unit 10 is measured (S120). If the current value I measured at this time is included in the normal range Rs (80 mA to 120 mA) (Y in S130), this current value I is stored as the reference current value Is (S140), and the current value I Is not included in the normal range Rs (N in S130), a warning lamp provided in the instrument panel is turned on, for example, to indicate an abnormality in the indicator lamp unit 10 (for example, installation of a nonstandard indicator lamp unit) Or a short circuit) (S200).

  And if lighting of the indicator lamp unit 10 after the 2nd time is detected (Y in S150), the electric current value I which flows into the indicator lamp unit 10 will be measured similarly (S160). When the disconnection of the indicator lamp unit 10 is detected based on the measured current value I and the reference current value Is (Y in S170 and S180), the indicator lamp unit 10 is blinked in a short cycle (S190, Indicator light blinking process), warn of disconnection. When no disconnection is detected (N in S180), the next indicator light unit 10 is awaited to be turned on (S150).

  In the direction indicator 1 described above, the current value I that flows when the indicator lamp unit 10 is first turned on after the vehicle is turned on is measured, and it is determined that the current value I is within the normal range Rs. The current value I is set as the reference current value Is, and subsequent disconnection detection is performed. Then, when the vehicle is turned off and the vehicle is turned on again, the current value I that flows when the indicator lamp unit 10 is first turned on after the vehicle is turned on is measured again. When it is determined that the current value I is within the normal range Rs, it is newly set as the reference current value Is. That is, every time the vehicle is turned on, a new reference current value Is corresponding to the current value fluctuation condition at that time is set.

  According to the present embodiment, the CPU 61 determines whether or not the current value I flowing through the indicator lamp unit 10 measured when the indicator lamp unit 10 is turned on for the first time after turning on the vehicle is included in the normal range Rs. Determine. Then, the CPU 61 detects the disconnection of the indicator lamp unit 10 using the current value I determined to be included in the normal range Rs as the reference current value Is.

  When the CPU 61 determines that the current value I flowing through the indicator lamp unit 10 measured when the indicator lamp unit 10 is turned on for the first time is not included in the normal range Rs, an abnormality has occurred in the indicator lamp unit 10. Notify that.

  As described above, according to the present invention, whether or not the current value I flowing through the indicator lamp unit 10 measured when the indicator lamp unit 10 is turned on for the first time after turning on the vehicle is included in the normal range Rs. Since the disconnection of the indicator lamp unit 10 is detected using the current value I determined to be included in the normal range Rs as the reference current value Is, the disconnection is detected every time the vehicle is turned on. Is reset within a normal range Rs determined in consideration of changes in current value fluctuation conditions, and therefore, the reference current corresponding to the current value fluctuation conditions when the indicator lamp unit 10 is turned on for the first time is reset. The disconnection of the indicator lamp unit 10 can be detected using the value Is, the current value fluctuation condition when the indicator lamp unit 10 is disconnected, and the current value fluctuation condition when the indicator lamp unit 10 is turned on for the first time. It never is erroneously detected disconnection of the display lamp unit 10 even if different. Accordingly, it is possible to prevent erroneous detection of disconnection that may occur after the replacement of the indicator lamp unit 10. Further, since it is not necessary to provide a function for resetting the reference current value, it can be configured at low cost.

  Further, since the disconnection is detected using the reference current value Is corresponding to the current value fluctuation condition at the time of the first lighting after the vehicle is turned on, the indicator lamp unit at the beginning of the operation of the lamp disconnection detection device 1 The current value I flowing through the reference lamp 10 is equal to the reference current value Is. Therefore, even if the current value fluctuation condition such as the outside air temperature changes after that, the current value I flowing through the indicator lamp unit 10 and the reference current value Is The current value I hardly changes to the extent that the difference value D exceeds the disconnection judgment reference value Cs, and erroneous detection of disconnection due to a change in the current value fluctuation condition after the vehicle is turned on is prevented. Thus, the accuracy of detection of disconnection of the indicator lamp unit 10 can be increased. Even if the difference value D exceeds the disconnection judgment reference value Cs due to a change in the current value fluctuation condition, the current value fluctuation at that time can be reduced by turning the vehicle power off and then on again. Since the reference current value Is corresponding to the condition is reset, the disconnection of the indicator lamp unit 10 can be detected correctly thereafter, and unnecessary lamp replacement or the like can be avoided.

  Further, when it is determined that the current value I flowing through the indicator lamp unit 10 measured when the indicator lamp unit 10 is turned on for the first time is not included in the normal range Rs, an abnormality has occurred in the indicator lamp unit 10. When the current value I flowing through the indicator lamp unit 10 is not included in the normal range Rs, for example, a nonstandard lamp through which a large current flows is mistakenly attached, or a failure such as a short circuit occurs. It is conceivable that the user has fallen into an abnormal state that may cause an accident. By notifying such an abnormal state, the accident can be prevented in advance.

  In the above-described embodiment, the direction indicator as one embodiment of the present invention has been described. However, the present invention is not limited to this, and the present invention is applied to a taillight lighting device, a headlight lighting device, and the like. May be.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, various modifications can be made without departing from the scope of the present invention.

1 Direction indicator (lamp break detection device)
10 Indicator unit (lamp)
20 Circuit open / close unit 30 Current sensor 40 Control unit 61 CPU (current value measurement means, disconnection detection means, initial current value determination means, lamp abnormality notification means)
64 EEPROM (normal range storage means)

Claims (2)

A current value measurement means for measuring the current flowing through the lamp to the lamp at the time of lighting of a vehicle, according to the measurement of the current value by the current value measuring means, based on the current value and the standards current value In a lamp disconnection detecting device comprising a disconnection detecting means for detecting disconnection of the lamp,
Normal range storage means for storing a normal range of a current value flowing through the lamp;
Initial current value determination means for determining whether or not the current value is included in the normal range for only the current value measured when the lamp is first turned on after the vehicle is powered on by the current value measurement means. And, and
The disconnection detecting means uses, as the reference current value, the current value measured at the time of the initial lighting of the lamp that is determined to be included in the normal range by the initial current value determining means. A lamp disconnection detecting device for detecting disconnection.   Lamp abnormality notification means for notifying that an abnormality has occurred in the lamp when it is determined by the initial current value determination means that the current value measured when the lamp is turned on for the first time is not included in the normal range. The lamp disconnection detecting device according to claim 1, comprising:

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