JP4600202B2 - Instrument lighting device - Google Patents

Description

  The present invention relates to an instrument illumination device that performs illumination such as an in-vehicle instrument.

  Conventionally, it is known to turn on a panel light source or the like of an in-vehicle instrument according to an input signal from an ignition switch, and to turn on the lighting so as to gradually increase the brightness (see, for example, Patent Document 1).

It is also known that the lighting of the lighting operation switch is detected and the panel illumination of the vehicle-mounted instrument is performed. In this case, the control means such as a microcomputer detects the turning on of the lighting operation switch, obtains the target luminance corresponding to the situation, and subsequently performs the illumination control so as to output this target luminance.
JP 2001-277905 A

  By the way, in the latter case, the control means detects the input of the lighting operation switch, and then determines the target brightness and starts the panel illumination, so that the control means takes a little processing time (for example, 100 ms to 200 ms). is required. For this reason, even if the lighting operation switch is turned on, the panel illumination is started with a slight delay, so that there may be a sense of incongruity in the delay of the illumination start timing.

  The present invention has been made in view of the above points, and it is an object of the present invention to provide an instrument illuminating device capable of quickly starting illumination when receiving an illumination start instruction and reducing an uncomfortable feeling of delay in illumination start timing. And

  In order to achieve the above object, the present invention employs technical means described in each claim.

In the instrument illumination device of the present invention according to claim 1,
Driving means for driving a light emitting element for illuminating a meter provided in an instrument panel in the passenger compartment, and a driving means for obtaining a target brightness based on external information when receiving an instruction to start lighting, so that the target brightness is obtained. Control means for operating
This control means is characterized in that the drive means is operated so that the initial brightness is set in advance during a period from when the illumination start instruction is received until the target brightness is determined.

  Thus, in the present invention, when the illumination start instruction is received, the light emitting element can be driven to give a preset initial luminance before the control means determines the target luminance and performs instrument illumination. Therefore, it is possible to immediately start lighting when receiving an illumination start instruction, and to reduce the uncomfortable feeling of delay in the illumination start timing.

  According to the second aspect of the present invention, a dimming circuit that generates dimming information indicating brightness according to a user's operation instruction is provided, and the control unit is configured to obtain target luminance and external luminance based on the dimming information. The drive means is actuated as described above.

  Accordingly, in the present invention, it is possible to take in luminance (brightness) information desired by the user using the dimming information of the dimming circuit and adjust the target luminance of the instrument.

In this invention of Claim 3, the lighting operation switch provided in the instrument panel and instruct | indicating lighting of the illuminating lamp which illuminates the circumference | surroundings of a meter is provided, and the light control circuit is operated when the lighting operation switch is turned on. While adjusting the brightness of an illumination lamp, it is set as the structure which produces light control information.

  Thus, in the present invention, it is possible to set the target luminance of the meter according to the brightness of the illumination lamp by using the dimming information indicating the brightness of the illumination lamp by the dimming circuit.

  In the present invention described in claim 4, an illuminance sensor for detecting illuminance information around the meter is provided, and the control means is driven so as to achieve the target luminance based on at least dimming information and illuminance information generated by the dimming circuit. The means is actuated.

  Accordingly, in the present invention, it is possible to adjust the luminance of the meter that matches the luminance (brightness) desired by the user and the illuminance (brightness) around the meter from the dimming information.

In the present invention described in claim 5, the control means regards the dimming information as information corresponding to the illuminance around the meter as the illuminance information around the meter, and based on the dimming information, the drive output to the drive means Storage means in which a luminance setting table for setting is set. Accordingly, in the present invention, it is possible to appropriately set the brightness of the meter according to the dimming information by the data setting of the brightness setting table.

In the present invention described in claim 6, the control means regards the dimming information and the illuminance information as information corresponding to the illuminance around the meter as the illuminance information around the meter, and based on the dimming information and the illuminance information. And a storage means in which a luminance setting table for setting the drive output to the drive means is set. Accordingly, in the present invention, it is possible to appropriately set the brightness of the instrument according to the dimming information and the illuminance information by the data setting of the brightness setting table.

  The present invention according to claim 7 is characterized in that the control means gives the initial luminance during the period using data giving the minimum luminance in the luminance setting table.

  Thereby, in the present invention, the minimum illumination can be performed promptly, and the transition to the target luminance can be smoothly and monotonously increased by setting the initial luminance to the minimum luminance, and the uncomfortable feeling can be reduced.

  In the present invention described in claim 8, in the luminance setting table, a drive duty ratio corresponding to the illuminance around the instrument is set as a drive output to the drive means. Accordingly, in the present invention, it is possible to perform duty control of the driving means using the driving duty ratio information as it is.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall configuration diagram showing an embodiment of the present invention, FIG. 2 is a timing chart showing the signal, and FIG. 3 is a luminance setting for setting a duty ratio (backlight luminance) in accordance with illuminance around the instrument. FIG. 4 is a flow chart showing the operation of the control means 71. FIG.

  In FIG. 1, 1 is, for example, a 12v vehicle-mounted battery, 2 is an ignition switch, 3 is a tail lamp switch serving as a lighting operation switch for instructing lighting of the vehicle lamp, 4 is a vehicle tail lamp, and 5 is an instrument panel in the vehicle interior. The illumination lamps of the mounted switches, 6 is a dimming circuit for adjusting the light emission luminance of the illumination lamp 5 in response to a user's operation instruction, 7 is an instrument unit, and 8a to 8n are various instruments 77a to 77n. Various sensors 9 are used to detect illuminance (brightness) around the instrument.

  In addition to the lamps 4, 5 and the dimming circuit 6 connected to the line s 1 on the non-battery 1 side of the tail lamp switch 3, an instrument unit 7 is connected. The instrument unit 7 is connected from the battery 1 via the tail lamp switch 3. 7 is supplied with the battery voltage Vb.

  The dimming circuit 6 has a resistance value according to a rotation operation of a depletion-type n-channel MOS transistor T1 that drives the illumination lamp 5 such as a switch and a brightness adjusting knob (not shown) installed around the meter unit 7. The luminance adjustment resistor 61 is changed, and the duty ratio is changed according to the resistance value of the luminance adjustment resistor 61, and the duty control circuit 62 that operates the MOS transistor T1 with the adjusted duty ratio is provided.

  Thereby, the dimming circuit 6 adjusts the light emission luminance of the illumination lamp 5 and uses the dimming signal s2 composed of the duty ratio output signal as the dimming (brightness) information instructed by the user. Is given to.

  The meter unit 7 includes a control means 71 composed of a microcomputer including a CPU, ROM and RAM, input resistors 72 and 73 constituting an input circuit for the battery voltage Vb, and an input protection diode constituting an input circuit for the dimming signal s2. 74, input resistors 75 and 76, various instruments 77a to 77n such as a pointer instrument and a display, and a light emitting element driving circuit 78 that illuminates the instrument as a backlight.

  The instrument unit 7 is arranged in the instrument panel in front of the driver's seat or in the center, and displays various information in the vehicle. Examples of the various instruments 77a to 77n include a speedometer and an engine tachometer composed of a pointer instrument, a fuel meter indicating the amount of remaining fuel in the fuel tank, an odometer, and a thermometer indicating the engine coolant temperature. Examples of the various sensors 8a to 8n include an engine rotation sensor, a speed sensor, a fuel sensor, a distance sensor, and a temperature sensor.

  The control means 71 is always supplied with power from the battery 1 and is always operable. Moreover, the control means 71 has the memory | storage means 71a comprised by a part of ROM.

  This storage means 71a has a brightness setting table as shown in FIG. In this brightness setting table, an output value for matching the brightness (brightness) of the switch illumination by the lamp 5 and the brightness (brightness) of the backlight illumination by the light emitting element driving circuit 78 is obtained by experiments or the like. The output value is set and stored in advance. In this brightness setting table, the drive duty ratio (target brightness) is set in the range from the minimum value Min to the maximum value Max according to the illuminance around the instrument.

  Here, the illuminance around the meter is only the duty ratio information obtained from the dimming signal s2 of the dimming circuit 6, or the duty ratio information and the illuminance information obtained by the illuminance sensor 9, for example, both are weighted with a predetermined weight. It means illuminance information obtained by addition or weighted average.

  The light emitting element driving circuit 78 has a configuration in which an enhancement type n-channel MOS transistor T2 is connected in series to a circuit in which n series circuits composed of current limiting resistors R1 to Rn and two light emitting diodes LED1 to LEDn are connected in parallel. Yes, the duty of the MOS transistor T2 is controlled, and the drive current of each of the light emitting diodes LED1 to LEDn is controlled. Although 2n light emitting element driving circuits 78 are arranged in this example, the value is determined according to the required performance as the backlight of the vehicle-mounted instrument. The light emitting diodes LED1 to LEDn are white light emitting diodes in this example.

  The operation of the present embodiment having the above configuration will be described.

  Here, the ON / OFF information of the ignition switch 2 is used as information for starting and ending the operation of the various meters 77a to 77n, but is an example not related to the control of the light emitting element driving circuit 78. .

  First, the operation of the peripheral circuit of the meter unit 7 will be described. As shown in FIG. 2B, when the tail lamp switch 3 is turned on, the battery voltage Vb is supplied from the battery 1 to the tail lamp 4, the dimming circuit 6, and the light emitting element driving circuit 78 via the line s1. Then, as shown in FIG. 2C, the duty control circuit 62 operates at a duty ratio corresponding to the resistance value of the brightness adjusting resistor 61, and the MOS transistor T1 is driven at this duty ratio, so that the illumination lamp 5 Is emitted at a desired luminance determined by the duty ratio. Further, a dimming signal s2 which is external information is supplied to the control means 71 from the drain D side of the MOS transistor T1.

  Next, the operation of the control means 71 will be described with reference to FIGS.

  In FIG. 4, the rising of the battery voltage Vb input from the line s1 is detected, and in step 101, it is determined whether or not the tail lamp switch 3 is ON. Actually, in order to prevent erroneous detection due to noise or the like superimposed on the line s1, the battery voltage Vb is detected a plurality of times, for example, every 20 ms. 3 is determined to be ON, and the process proceeds to step 102.

  Subsequently, in step 102, the driving duty ratio that gives the minimum luminance (Min luminance) is read from the luminance setting table in the storage unit 71 a and is output to the light emitting element driving circuit 78. Therefore, as shown in FIG. 2D, a drive duty output s3 is generated.

  As a result, as shown in FIG. 2 (e), the preparatory period T0 until the control means 71 calculates and determines the desired target luminance also has a minimum (minimum) level luminance that is a preset initial luminance. Thus, backlight illumination can be performed. In this way, when the tail lamp switch 3 is turned on (that is, an illumination start instruction) is detected, illumination of the instrument is started immediately, and the uncomfortable feeling of delay in the illumination start timing can be reduced.

  In addition, by setting the brightness to the minimum level in the preparation period T0, the transition to the target brightness (≧ minimum brightness) also increases smoothly and monotonously, and the discomfort of the brightness change can be reduced. Of course, in this example, the luminance is not limited to the minimum luminance Min, but may be a luminance close to that.

  Subsequently, when the dimming signal s2 (that is, the duty ratio output signal) is received from the dimming circuit 6 in step 103, the process proceeds to step 104. In step 104, the dimming luminance of the dimming circuit 6 is calculated from the duty ratio of the signal s2 (that is, the time width ratio of the ON or OFF signal to the cycle).

  Subsequently, in step 105, the dimming luminance obtained in step 104 is regarded as equivalent to the meter ambient illuminance, and the driving duty ratio that gives the desired target luminance is read from the luminance setting table to determine the target luminance. Alternatively, in Step 105, a value obtained by weighted averaging the dimming luminance obtained in Step 104 and the illuminance information that is external information detected by the illuminance sensor 9 is regarded as instrument peripheral illuminance, and a desired target luminance is determined from the luminance setting table. The drive duty ratio to be applied is read to determine the target brightness.

  Subsequently, in step 106, an output process is performed on the light emitting element driving circuit 78 in accordance with the driving duty ratio.

  As described above, in the present embodiment, in step 102, the minimum luminance is set and output as the initial luminance, and the preparation period T0, for example, the period of 50 to 100 ms, from the time when the target luminance is determined in steps 103 to 105, is set. However, it is possible to illuminate the instrument with the minimum luminance, and to reduce the uncomfortable feeling due to the delay of the illumination start timing.

  In this embodiment, the brightness (brightness) of the switch illumination by the lamp 5 and the brightness (brightness) of the backlight illumination by the light emitting element driving circuit 78 can be matched. In that case, the latter which combined the illumination sensor 9 can raise a matching degree more.

  The characteristic points of this embodiment will be summarized below.

  In the present embodiment, the driving means T2 for driving the light emitting elements LED1 to LEDn for illuminating the meter, and when receiving the illumination start instruction, the target brightness is obtained based on the external information, and the driving means T2 so as to be the target brightness. The control means 71 operates the driving means T2 so that the initial brightness is set in advance during the period from when the illumination start instruction is received until the target brightness is determined. It is characterized by. Thereby, in this embodiment, when the illumination start instruction is received, the light emitting elements LED1 to LEDn are driven so as to give the preset initial luminance before the control means 71 determines the target luminance and performs instrument illumination. It becomes possible. Therefore, it is possible to immediately start lighting when receiving an illumination start instruction, and to reduce the uncomfortable feeling of delay in the illumination start timing.

  In the present embodiment, a dimming circuit 6 that generates dimming information indicating brightness according to a user's operation instruction is provided, and the control unit 71 is set to target luminance based on the dimming information as external information. The drive means T2 is actuated. Thereby, in the present embodiment, it is possible to take in luminance (brightness) information desired by the user using the dimming information of the dimming circuit 6 and adjust the target luminance of the instrument.

  In the present embodiment, a lighting operation switch 3 for instructing lighting of the illumination lamp 5 is provided, and the dimming circuit 6 is activated when the lighting operation switch 3 is turned on to adjust the brightness of the illumination lamp 5 and to control the dimming information. The resulting configuration. Thereby, in this embodiment, it becomes possible to set the target brightness | luminance of a meter according to the brightness of the illuminating lamp 5 using the dimming information which shows the brightness of the illuminating lamp 5 by the dimming circuit 6. FIG.

  In the present embodiment, an illuminance sensor 9 for detecting illuminance information around the meter is provided, and the control means 71 is a drive means T2 so that the target brightness is obtained based on at least dimming information and illuminance information generated by the dimming circuit 6. Is operated. Accordingly, in the present embodiment, it is possible to adjust the luminance of the meter by matching the luminance (brightness) desired by the user with the illuminance (brightness) around the meter based on the dimming information.

  In the present embodiment, the control unit 71 includes a storage unit 71a in which a luminance setting table for setting a drive output to the drive unit T2 is set based on dimming information as meter peripheral illumination. Thereby, in this embodiment, it becomes possible to set appropriately the brightness | luminance of the meter according to light control information by the data setting of this brightness | luminance setting table.

  In the present embodiment, the control unit 71 includes a storage unit 71a in which a luminance setting table for setting a drive output to the drive unit T2 is set based on dimming information and illuminance information as meter peripheral illuminance. Thereby, in this embodiment, it becomes possible to set appropriately the brightness | luminance of the meter according to light control information and illumination intensity information by the data setting of this brightness | luminance setting table.

  In this embodiment, the control means 71 is characterized in that during the period, the initial brightness is given using data giving the minimum brightness in the brightness setting table. Thereby, in this embodiment, the minimum illumination can be performed quickly, and the transition to the target luminance can be smoothly and monotonously increased by setting the initial luminance to the minimum luminance, and the sense of incongruity can be reduced.

  In the present embodiment, in the luminance setting table, a drive duty ratio corresponding to the illuminance around the instrument is set as a drive output to the drive means T2. Thereby, in this embodiment, it becomes possible to perform duty control of the drive means T2 using this drive duty ratio information as it is.

It is a whole lineblock diagram showing one embodiment of the present invention. It is a timing chart which shows the signal in FIG. It is a characteristic view which shows the brightness | luminance setting table which sets a duty ratio (brightness of a backlight) according to meter periphery illumination intensity. 3 is a flowchart showing the operation of a control means 71.

Explanation of symbols

1 On-board battery 2 Ignition switch 3 Tail lamp switch (lighting operation switch)
5 Switches for Lighting 6 Dimming Circuit 7 Meter Units 8a to 8n Various Sensors 9 Illuminance Sensor 61 Brightness Adjustment Resistor 62 Duty Control Circuit 71 Control Unit 71a Storage Units 77a to 77n Various Meters 78 Light Emitting Element Drive Circuit T2 MOS Transistor (Driving means)
LED1-LEDn Light-emitting diode (light-emitting element)

Claims (8)

Driving means for driving a light emitting element for illuminating a meter provided in an instrument panel in the vehicle interior ;
A control means for obtaining a target brightness based on external information when the illumination start instruction is received and operating the driving means so as to obtain the target brightness;
The control illuminator is characterized in that the driving means is operated so that a predetermined initial luminance is obtained during a period from when the illumination start instruction is received until the target luminance is determined. A dimming circuit that generates dimming information indicating brightness according to a user's operation instruction is provided,
2. The instrument illumination device according to claim 1, wherein the control means operates the driving means so as to achieve the target luminance based on the dimming information as the external information. Provided in the instrument panel, provided with a lighting operation switch for instructing to turn on an illuminating lamp that illuminates the periphery of the instrument ,
3. The instrument lighting device according to claim 2, wherein the dimming circuit operates when the lighting operation switch is turned on to adjust the brightness of the illuminating lamp and generate the dimming information. An illuminance sensor that detects illuminance information around the instrument is provided.
3. The instrument illumination according to claim 2, wherein the control unit operates the driving unit so as to achieve the target luminance based on at least the dimming information and the illuminance information generated by the dimming circuit. apparatus. The control means regards the dimming information as information corresponding to illuminance around the meter as illuminance information around the meter, and a brightness setting table for setting a drive output to the driving means based on the dimming information The instrument illumination device according to claim 2, further comprising a storage unit in which is set. The control means regards the dimming information and the illuminance information as information corresponding to the illuminance around the meter as the illuminance information around the meter, and based on the dimming information and the illuminance information, to the driving means 5. The instrument illumination device according to claim 4, further comprising storage means in which a luminance setting table for setting the drive output is set.   The instrument illumination device according to claim 5 or 6, wherein the control means gives the initial luminance using data giving a minimum luminance in the luminance setting table during the period.   The instrument illumination device according to claim 5 or 6, wherein a drive duty ratio corresponding to illuminance around the instrument is set as a drive output to the drive means in the brightness setting table.

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