JP6337649B2 - LED lamp unit and vehicle lamp device - Google Patents

Description

  The present invention relates to an LED lamp unit and a vehicle lamp device.

  In recent years, with the widespread use of light emitting diodes (LEDs), home appliances and the like often use LEDs as light sources. However, there are many direction indicators (blinkers) and tail lights (tail lamps) mounted on a vehicle that use a filament light bulb (incandescent light bulb) that is superior in price to LEDs as a light source. Filament bulbs have a shorter lifetime than LEDs. Therefore, in general, these vehicular lamp devices are provided with a failure detection circuit that detects a disconnection of the filament, that is, a so-called “out of bulb” due to a reduction in current consumption by the light bulb.

  On the other hand, parts that can replace the light source of turn signals and tail lamps from filament bulbs to LEDs are sold as parts for car mania. LEDs consume significantly less current than filament bulbs. For this reason, these include a so-called “warning canceller” that prevents erroneous detection of a broken ball by the failure detection circuit. As a technique regarding the warning canceller, for example, there is one disclosed in Patent Document 1 below.

JP 2002-76439 A

  Like the technique disclosed in Patent Document 1, many of the warning cancellers consume a current equivalent to the current consumed by the filament light bulb by a dummy resistor. Thereby, it is possible to prevent erroneous detection by the failure detection circuit by flowing the same current as in the case of using the filament bulb, but wasteful energy is consumed as heat by the dummy resistor. Therefore, these warning cancellers are not very desirable from the viewpoint of energy saving.

  SUMMARY An advantage of some aspects of the invention is to provide an LED lamp unit and a vehicle lamp device that can prevent erroneous detection of a failure while contributing to energy saving.

In order to achieve the above object, the LED lamp unit according to claim 1 of the claims includes a failure detection unit that outputs lamp failure information when the lamp current becomes smaller than a predetermined current value set in advance. An LED lamp unit having a light-emitting diode that can be connected to the lamp device provided in place of the lamp and has a consumption current less than the predetermined current value, the lamp current being the predetermined current value and A boosting unit that consumes a dummy current greater than the difference from the current consumption of the light emitting diode and boosts and outputs an input voltage is provided in the light emitting diode.
The lamp current includes the current consumption of the light emitting diode and the dummy current.
And wherein the Rukoto such to the sum of the over current.

  In the invention of the LED lamp unit according to the first aspect of the present invention, the lamp current includes a boosting unit that consumes a current equal to or greater than a difference between a predetermined current value and the consumption current of the light emitting diode and boosts and outputs the input voltage. Thus, even if an LED lamp unit having a light emitting diode less than a predetermined current value set in advance to output lamp failure information is connected to the lamp device instead of the lamp, the lamp current remains at the predetermined current value. No smaller than. In addition, the boosting unit that consumes a current greater than the difference between the predetermined current value and the consumption current of the light emitting diode boosts and outputs the input voltage. As a result, the energy consumed by the current that flows in excess of the current consumed by the light emitting diode is not simply consumed as heat, but is boosted and output as a voltage. Can be consumed.

  Further, the LED lamp unit according to claim 2 of the claim is the LED lamp unit according to claim 1, wherein the boosting unit is configured such that the current consumption of the light emitting diode is greater than the current value during normal lighting. If the current consumption is smaller or the current consumption of the light emitting diode is larger than the current value during normal lighting, the boosting is not performed.

  In the invention of the LED lamp unit according to claim 2, the boosting unit does not boost when the current consumption of the light emitting diode is smaller than the current value at the time of normal lighting. That is, when the current value is smaller than the normal lighting state, that is, when the light emitting diode fails in the open state (open mode), the boosting unit does not boost the input voltage. Further, even when the current consumption of the light emitting diode is larger than the current value during normal lighting, that is, when the light emitting diode fails in a short circuit state (short mode), the boosting unit does not boost the input voltage. As a result, when the light emitting diode breaks down, the current exceeding the difference between the predetermined current value and the consumption current of the light emitting diode by the boosting unit is not consumed, so that a current less than the predetermined current value flows as the lamp current. Therefore, when the light emitting diode fails, the failure detector of the lamp device outputs lamp failure information.

  Further, the vehicular lamp device described in claim 3 of the claims is configured by a device specification that uses a filament light bulb as a vehicle direction indicator or taillight, and exceeds a predetermined current value set in advance. It is a vehicle lamp device provided with the failure detection part which outputs the failure information of the said filament bulb when lamp current becomes small, Comprising: It replaces with the said filament bulb, and uses the LED lamp unit of Claim 1 or 2 characterized by the above-mentioned. And

  In the invention of the vehicle lamp device according to claim 3, the LED lamp unit according to claim 1 or 2 is used in place of the filament light bulb functioning as a vehicle direction indicator or tail light. As a result, even if an LED lamp unit having a light emitting diode having a current value less than a preset predetermined current value is connected to the vehicle lamp device instead of the filament light bulb, the lamp current does not become smaller than the predetermined current value. In addition, the boosting unit that consumes a current greater than the difference between the consumption current value of the filament bulb and the consumption current of the light emitting diode boosts and outputs the input voltage. As a result, the energy generated by the current that flows excessively relative to the current consumption of the light emitting diode is not simply consumed as heat, but is boosted and output as a voltage, so that it can be consumed as drive energy for other devices. .

  In the invention of the LED lamp unit, the lamp current does not become smaller than the predetermined current value even if the LED lamp unit having the light emitting diodes less than the predetermined current value set in advance is connected to the lamp device instead of the lamp. In addition, the energy consumed by the current that flows in excess of the current consumed by the light-emitting diode is not simply consumed as heat, but is output as a boosted voltage, which is consumed as drive energy for other equipment. Can be done. Therefore, erroneous detection of a failure can be prevented while contributing to energy saving.

  In the invention of the vehicle lamp device, even if an LED lamp unit having a light emitting diode having a current value less than a preset predetermined current value is connected to the vehicle lamp device instead of the filament light bulb, the lamp current is a predetermined current. It will not be smaller than the value. In addition, the energy consumed by the current that flows in excess of the current consumed by the light-emitting diode is not simply consumed as heat, but is output as a boosted voltage, which is consumed as drive energy for other equipment. Can be done. Therefore, erroneous detection of a failure can be prevented while contributing to energy saving.

It is a block diagram which shows the structural example of the LED lamp unit which concerns on one Embodiment of this invention, and the structural example of the vehicle lamp device using the same. FIG. 2A is a block diagram showing another configuration example of the LED lamp unit according to the embodiment of the present invention. FIG. 2B is a circuit diagram illustrating a configuration example of the boosting unit. It is explanatory drawing which shows the example of the output destination of an LED lamp unit, FIG. 3 (A) is the example which made the output destination the external load, FIG.3 (B) is the example which made the output destination the battery.

  Hereinafter, a vehicle lamp device 10 in which an LED lamp unit of the present invention is applied to a vehicle direction indicator or taillight will be described as an embodiment of the present invention with reference to the drawings. The vehicle lamp device 10 is also an embodiment of the vehicle lamp device of the present invention. The vehicle direction indicator (commonly called turn signal) is called a turn signal lamp or a turn lamp, and is provided at the front, side, and rear of the vehicle. The direction indicator may function as a hazard lamp. Further, the taillight of the vehicle is provided behind the vehicle and is called a tail lamp or a brake lamp.

  First, a basic configuration of the vehicular lamp device 10 will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration example of the LED lamp unit 20a and a configuration example of a vehicle lamp device 10 using the LED lamp unit 20a.

  As shown in FIG. 1, the vehicular lamp device 10 is mainly configured by a lighting control unit 11 and an LED lamp unit 20a electrically connected thereto. The lighting control unit 11 is a control unit that controls turning on and off of a turn signal lamp and a tail lamp connected to the lighting control unit 11, and includes a control circuit (not shown).

  For example, when the turn signal lamps provided on both sides in the vehicle width direction, that is, on the left and right sides are connected, the lighting control unit 11 turns the turn signal on the corresponding side according to the input of the operation information of the right turn or left turn instruction by the driver. The lamps are blinked at a predetermined cycle, or the turn signal lamps on both sides are blinked at a predetermined cycle according to the input of hazard operation information. For example, when a tail lamp is connected to the lighting control unit 11, the tail lamp is turned on together with the front light. When a brake lamp is connected to the lighting control unit 11, the brake lamp is turned on according to the input of brake operation information by the driver or the like.

  The lighting control unit 11 that performs lighting control of such a lamp receives a driving voltage supplied from a battery Batt (for example, a nominal voltage of 24 V), and supplies power that can light the filament bulb to a turn signal lamp or the like. Therefore, the lighting control unit 11 includes a failure detection unit 13 that can detect a failure of a light bulb due to a filament breakage, that is, a breakage of a bulb.

  For example, the failure detection unit 13 can detect “out of bulb” when a threshold current Ith that is smaller than a lamp current flowing through a filament bulb in a normal state by a predetermined amount is set and a current smaller than this flows through the lamp. It is configured as follows. Specifically, for example, the failure detection unit 13 is configured to detect the lamp current IL flowing through the lamp by the voltage across the resistor through which it flows and to output failure information when the voltage is less than a preset voltage.

  That is, the occurrence of a failure is detected when the generated voltage is lower than the voltage across the resistor generated when the threshold current Ith flows through the resistor. For example, the failure information is displayed on the instrument panel as a warning lamp. Etc. are displayed. The normal lamp current is preset by a vehicle manufacturer or the like that provides the lighting control unit 11. The failure detection unit 13 is incorporated in the lighting control unit 11 and is not configured so that the user of the vehicle can customize the circuit configuration.

  In the present embodiment, the LED lamp unit 20a is connected to the lighting control unit 11 configured as described above. That is, the LED lamp unit 20a is used instead of the filament bulb. The LED lamp unit 20a includes a light emitting diode 23 and a booster 30. The input terminal Ti is connected to the output side of the lighting controller 11, and the ground terminal GND is at a reference potential (ground, minus terminal of the battery Batt). It is connected.

  The light emitting diode 23 includes a plurality of light emitting diode elements (hereinafter referred to as “LED elements”) and a current limiting element such as a resistor, and is connected between the input terminal Ti and the ground terminal GND. In the present embodiment, for example, three LED rows in which five LED elements are electrically connected in series are electrically connected in parallel to form the light emitting diode 23. The LED current Ia flowing through the light emitting diode 23 is the sum of the currents flowing through the plurality of LED elements. Note that the mechanical arrangement of these LED elements is appropriately set according to the specific shape of the turn signal lamp, tail lamp, etc., and the emission color is also a color suitable for these specific applications (for example, , Orange or red) as appropriate.

  The step-up unit 30 is, for example, a DC / DC converter that employs a chopper method. In the present embodiment, since the output voltage 24V of the battery Batt is input as the input voltage Vi, for example, the output voltage Vo obtained by boosting this to about 30V is output to the output terminal To. For example, a load 50 is connected to the output terminal To. The load 50 is, for example, another device mounted on the vehicle and is arbitrary, and is represented by a broken line in FIG. In FIG. 1, a reference numeral 30 a is attached in parentheses in order to distinguish from a booster 30 b described later with reference to FIG. 2. Moreover, the code | symbol G shows the ground terminal of the pressure | voltage rise part 30 connected to the ground terminal GND.

  The step-up unit 30 is configured so that the output voltage Vo can be set to an arbitrary value by controlling the on / off duty of a switching transistor interposed between the input-side inductance and the output-side capacitor. A dummy current Ib greater than the difference between the threshold current Ith and the LED current Ia flows. For example, the input current of the boosting unit 30 is detected, and the on / off duty can be controlled so that the current becomes equal to or higher than the dummy current Ib.

  Further, when the input current of the booster 30 is at least equal to or greater than the dummy current Ib from the amount of power consumed by the load 50, for example, the load current or the load voltage is detected and the load current or the load voltage is set to a predetermined value. The on / off duty is configured to be controllable. In this case, a constant current or a constant voltage can be supplied to the load 50. In the case of outputting an almost integral multiple of the input voltage Vi as the output voltage Vo, for example, a charge pump method may be adopted as the circuit method of the booster 30.

  In the LED lamp unit 20a configured as described above, the sum of the LED current Ia passing through the light emitting diode 23 and the dummy current Ib passing through the booster 30a flows as the lamp current IL (IL = Ia + Ib). The lamp current IL corresponds to the current consumed by the filament bulb that is originally connected to the lighting control unit 11. Thereby, even if the LED current Ia flowing through the light emitting diode 23 is less than the threshold current Ith, the insufficient current (= threshold current Ith−LED current Ia) is set as the dummy current Ib (= threshold current Ith−LED current Ia). Since the booster 30 flows, even if the LED lamp unit 20a is connected instead of the filament light bulb, the failure detection unit 13 of the lighting control unit 11 does not detect a failure by mistake. That is, the booster 30 functions as a warning canceller and prevents erroneous detection by the failure detector 13. The warning canceller may also be called a “warning canceller”.

  The booster 30 may be configured as shown in FIG. 2, for example. 2A is a block diagram showing the configuration of an LED lamp unit 20b as another configuration example of the LED lamp unit 20, and FIG. 2B is a boosting unit of the LED lamp unit 20b. A circuit diagram showing a configuration example of 30b is shown. Components substantially the same as the LED lamp unit 20a shown in FIG. 1 are denoted by the same reference numerals.

  As shown in FIG. 2A, the LED lamp unit 20b according to another configuration example detects the LED current Ia flowing through the light emitting diode 23 by the voltage across the resistor 25, and the LED current Ia is normally turned on. The boosting operation by the boosting unit 30b is performed when the current value Ig is a predetermined current value Ig, and the boosting operation by the boosting unit 30b is not performed when the LED current Ia is lower than the predetermined current value Ig. The predetermined current value Ig is determined in advance in consideration of individual specific characteristics of the light emitting diode 23 based on the results of experiments or computer simulations.

  As shown in FIG. 2 (B), the booster 30b includes a booster circuit 33, a comparator 35, and a comparison voltage source 37. The booster circuit 33 configures, for example, a DC / DC converter adopting a chopper method, similarly to the booster circuit configuring the booster 30 (30a) described with reference to FIG. The boosting unit 30b is provided with an enable terminal for controlling whether or not a boosting operation is possible. In this embodiment, when an H level voltage is input to the enable terminal, the boosting operation is performed, and the L level voltage is changed. The booster 30b is configured to stop the boosting operation when input.

  The comparator 35 has a non-inverting input terminal connected to the light emitting diode 23 side of the resistor 25 and an inverting input terminal connected to the comparison voltage source 37. The output terminal of the comparator 35 is connected to the enable terminal of the booster 30b. The comparison voltage source 37 is configured to generate a predetermined reference voltage. This reference voltage is generated at both ends of the resistor 25 when, for example, the normal current Ig of the light emitting diode 23 flows through the resistor 25. The voltage value is set slightly lower (for example, about 90%) than the voltage value.

  The input impedance of the comparator 35 is very high. Therefore, the current flowing from the light emitting diode 23 to the non-inverting input terminal can be ignored, and almost the LED current Ia flows through the resistor 25 as it is. As a result, when the voltage Vs across the resistor 25 becomes higher than the reference voltage of the comparison voltage source 37 (when the LED current Ia exceeds the predetermined current value Ig), an H level voltage is output from the output terminal of the comparator 35. Is done. As a result, an H level voltage is input to the enable terminal, and the boosting operation by the boosting unit 30b is performed. On the other hand, when the voltage Vs across the resistor 25 becomes lower than the reference voltage of the comparison voltage source 37 (when the LED current Ia becomes smaller than the predetermined current value Ig), an L level voltage is output from the output terminal of the comparator 35. Is output. Therefore, the L level voltage is input to the enable terminal, and the boosting operation by the boosting unit 30b is stopped.

  By configuring the LED lamp unit 20b in this way, when the LED current Ia flows more than the predetermined current value Ig that flows when the light emitting diode 23 is normally lit, the boosting operation by the boosting unit 30b is performed. On the other hand, when the LED current Ia is smaller than the predetermined current value Ig, the boosting operation by the boosting unit 30b is stopped. Thereby, when a part of LED element which comprises the light emitting diode 23 fails in an open state (open mode), the pressure | voltage rise operation by the pressure | voltage rise part 30b is not performed. Therefore, when the light emitting diode 23 fails due to the open mode, the dummy current Ib from the booster 30b is not consumed, so that the lamp current IL becomes less than the threshold current Ith, so that the failure detector 13 outputs lamp failure information. Thus, the failure of the light emitting diode 23 can be notified.

  Further, the non-inverting input terminal and the inverting input terminal of the comparator 35 are connected in reverse to the circuit example shown in FIG. That is, the non-inverting input terminal is connected to the comparison voltage source 37, and the inverting input terminal is connected to the light emitting diode 23 side of the resistor 25. As a result, when the voltage Vs across the resistor 25 becomes slightly lower than the reference voltage of the comparison voltage source 37 (for example, about 110%) (when the LED current Ia becomes smaller than the predetermined current value Ig), the comparator When the voltage of H level is output from the output terminal 35 and the voltage Vs across the resistor 25 becomes higher than the reference voltage of the comparison voltage source 37 (when the LED current Ia becomes larger than the predetermined current value Ig), the comparator An L level voltage is output from the 35 output terminals.

  Therefore, when the LED current Ia flows less than the predetermined current value Ig flowing when the light emitting diode 23 is normally lit, the boosting operation by the boosting unit 30b is performed, whereas the LED current Ia is the predetermined current value Ig. When the current value Ig is higher than the current value Ig, the boosting operation by the boosting unit 30b is stopped. Therefore, when a part of the LED elements constituting the light emitting diode 23 fails in a short circuit state (short mode), the boosting operation by the boosting unit 30b is not performed. Therefore, even when the light emitting diode 23 is in a failure due to the short mode, the dummy current Ib is not consumed by the boosting unit 30b. Therefore, the failure detecting unit 13 displays the lamp failure information when the lamp current IL is less than the threshold current Ith. The failure can be notified by outputting.

  By providing both the open mode failure detection comparator and the short mode failure detection comparator, failure detection by the failure detection unit 13 corresponding to both failure modes becomes possible.

  An example of the load 50 to which the output voltage Vo boosted by the booster 30 (30a, 30b) is supplied is shown in FIG. FIG. 3 is an explanatory diagram showing an example of the output destination of the LED lamp unit 20 (20a, 20b). FIG. 3 (A) shows an example in which the output destination is a load 50, and FIG. This is an example in which the output destination is a battery Batt.

  When the output voltage Vo is supplied as the load 50 to another device mounted on the vehicle, as shown in FIG. 3A, the output terminal To of the LED lamp unit 20 (20a, 20b) is connected. Connect the load 50. In this case, the booster 30 (30a, 30b) boosts the input voltage Vi so that the output voltage Vo becomes a voltage suitable for the load 50, for example. Thereby, the energy by the dummy current Ib flowing through the booster 30 (30a, 30b) is consumed as drive energy for other device devices and the like.

  On the other hand, when supplying the output voltage Vo to the battery Batt connected to the lighting control unit 11 as the load 50, the LED lamp unit 20 (20a, 20b) is connected via the diode 60 as shown in FIG. The battery Batt is connected to the output terminal To. The diode 60 is a rectifying element for preventing a backflow that prevents a current from flowing from the battery Batt toward the LED lamp unit 20 (20a, 20b). In this case, for example, the booster 30 (30a, 30b) boosts the input voltage Vi so that the output voltage Vo becomes a voltage suitable for the charging voltage of the battery Batt. Thereby, the energy by the dummy current Ib flowing through the booster 30 (30a, 30b) is consumed as the charging energy of the battery Batt. In this example, the diode 60 may not be provided.

  As described above, in the LED lamp unit 20 (20a, 20b) according to the present embodiment, in the vehicle lamp device 10, a dummy current equal to or greater than the difference between the threshold current Ith and the LED current Ia of the light emitting diode 23 is used as the lamp current IL. A booster 30 that consumes the current Ib and boosts and outputs the input voltage Vi is provided. As a result, the LED lamp unit 20 (20a, 20b) having the light emitting diodes 23 having a threshold current less than the preset threshold current Ith for outputting the filament bulb failure information is connected to the vehicle lamp device 10 instead of the filament bulb. Even so, the lamp current IL does not become smaller than the threshold current Ith. Further, the booster 30 that consumes a dummy current Ib that is equal to or greater than the difference between the threshold current Ith and the LED current Ia of the LED lamp unit 20 (20a, 20b) boosts the input voltage Vi and outputs an output voltage Vo. Thereby, the energy consumed by the dummy current Ib that flows excessively with respect to the LED current Ia of the light emitting diode 23 is not simply consumed as heat, but is boosted to the output voltage Vo and output. It can be consumed as driving energy in a load 50 such as a device. For example, the load 50 may be returned to the battery Batt via the diode 60. Accordingly, since the battery Batt is charged and can be reused as regenerative energy, it is possible to prevent erroneous detection of a failure by the failure detection unit 13 while contributing to energy saving.

  In the present embodiment described above, the booster 30 is made to consume a dummy current Ib that is equal to or greater than the difference between the threshold current Ith (predetermined current value) and the LED current Ia (light-emitting diode consumption current) as the lamp current. However, the dummy current Ib may be consumed by the step-down circuit that outputs the output voltage Vo lower than the input voltage Vi. Thereby, for example, regenerative energy can be reused for in-vehicle devices that can be driven at 12 V or 5 V lower than the nominal voltage of the battery Batt.

  In the above-described embodiment, the light emitting diode 23 is described by exemplifying an LED module including a plurality of LED elements, but may be a single light emitting diode element.

  Further, in the above-described embodiment, the case where the LED lamp unit 20 (20a, 20b) is used instead of the turn signal lamp or the tail lamp filament bulb provided outside the vehicle has been described as an example. LED lamp units 20 (20a, 20b) may be used instead of filament lamps such as room lamps, instrument panel lamps, or lamps provided in engine compartments or luggage spaces.

10 ... Vehicle lamp device (lamp device)
DESCRIPTION OF SYMBOLS 11 ... Lighting control part 13 ... Failure detection part 20, 20a, 20b ... LED lamp unit 23 ... Light emitting diode 25 ... Resistance 30, 30a, 30b ... Boosting part 33 ... Boosting circuit 35 ... Comparator 37 ... Comparison voltage source 50 ... Load 60 ... Diode Batt ... Battery G, GND ... Ground terminal IL ... Lamp current Ia ... LED current (light-emitting diode current consumption)
Ib ... Dummy current Ig ... Normal current (current value when the light emitting diode is normally lit)
Ith ... Threshold current (predetermined current value)
Ti ... Input terminal To ... Output terminal Vi ... Input voltage Vo ... Output voltage

Claims (3)

When the lamp current becomes smaller than a predetermined current value set in advance, a lamp device having a failure detection unit that outputs lamp failure information can be connected instead of the lamp, and the consumption current is the predetermined current. An LED lamp unit having a light emitting diode that is less than the value,
A boosting unit that consumes a dummy current greater than the difference between the predetermined current value and the consumption current of the light emitting diode as the lamp current and boosts and outputs an input voltage is provided in the light emitting diode.
In parallel with the
The lamp current, LED lamp unit, wherein the consumption current of the light emitting diode, a Rukoto such to the sum of the dummy current. The boosting unit does not perform the boosting when the current consumption of the light emitting diode is smaller than the current value during normal lighting or when the current consumption of the light emitting diode is larger than the current value during normal lighting. The LED lamp unit according to claim 1, wherein Vehicle comprising a device specification that uses a filament light bulb as a vehicle direction indicator or taillight, and having a failure detection unit that outputs failure information of the filament light bulb when the lamp current becomes smaller than a predetermined current value set in advance A lamp device for a vehicle according to claim 1 or 2.
An LED lamp unit according to claim 1 is used instead of the filament light bulb.

Images