JP2011094659A - Lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting device in which the complication of a composition and a rise of manufacturing cost can be suppressed. <P>SOLUTION: The lighting device includes a plurality of light sources L1-L4, a plurality of transistors T1-T4 provided at the respective light sources L1-L4 in order to light the fourth light source L4 among the light sources L1-L4 with first luminance, and a control means 14 for outputting drive waveform signals to the transistors T1-T4 based on a predetermined input signal. The control means 14 outputs a drive waveform signal having a first duty ratio to the fourth transistor T4 connected to the fourth light source L4 among the transistors T1-T4 in order to light other light sources L1-L3 except the fourth light source L4 with second luminance lower than the first luminance while the fourth light source L4 is lighted at the first luminance. The control means also outputs a drive waveform signal having a second duty ratio set to be a value smaller than the first duty ratio to other transistors T1-T3 except the fourth transistor T4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an illumination device having a plurality of display units (illuminated units) and provided with a light source for display unit illumination for each display unit.

  A conventional lighting device as a display device for a vehicle has a light source such as an LED disposed immediately below (behind) a display unit (illuminated unit) to be individually illuminated, and the light source emits the light. One that transmits and illuminates each display unit is known, and is disclosed in, for example, Patent Document 1.

  As the display unit to be illuminated by the vehicle display device, for example, there is an AT indicator display unit for notifying the AT shift position. The AT indicator display unit includes parking “P”, reverse “R”, and neutral “N”. In addition, a plurality of display units indicating a shift range such as the drive “D” are provided.

JP-A-7-128093

  In such an AT indicator display unit, a light source disposed behind the display unit corresponding to the shift change (for example, the indicator display unit corresponding to the drive “D”) is turned on in response to the shift change of the AT shift. Thus, the user can recognize the selected position of the AT shift after the shift change (for example, the shift range position of the drive “D”).

  However, at night or when the surroundings are dark, it is difficult to visually recognize (recognize) other indicator display portions that are not selected by the AT shift, which causes inconvenience. In order to solve such a problem, in addition to each light source prepared for each display unit of the AT indicator display unit, a plurality of dedicated light sources for shining the frame of the AT indicator display unit are prepared. Each dedicated light source is caused to emit light in conjunction with an illumination switch, and the light emitted from each dedicated light source is guided to a light guide provided on the frame, thereby being disposed behind the AT indicator display unit. It is possible to cause the other indicator display unit that is not illuminated by the light source to emit light.

However, since the illumination device using the dedicated light source and the light guide requires the dedicated light source and the light guide, the configuration as the illumination device is complicated, and the design and assembly of the AT indicator display unit are performed. Not only is the operation complicated, but there is a problem in that the product cost of the vehicular display device including the illumination device increases.
In view of the above-described problems, an object of the present invention is to provide a lighting device capable of suppressing the complexity of the configuration and the increase in product cost.

  The present invention is based on a plurality of light sources, a plurality of switch means provided for each of the light sources to shine a predetermined light source of the light sources with a first luminance, and based on a predetermined input signal. Control means for outputting a drive waveform signal to each switch means, and the control means uses a light source other than the predetermined light source when the predetermined light source shines at the first luminance. The drive waveform signal having a first duty ratio is output to a predetermined switch means connected to the predetermined light source among the switch means to shine at a second brightness lower than the first brightness. The drive waveform signal having a second duty ratio set to a value smaller than the first duty ratio is output to switch means other than the predetermined switch means.

  According to the present invention, it is possible to provide an illuminating device that can achieve the initial purpose and can suppress the complexity of the configuration and the increase in product cost.

The block diagram which shows the electric constitution of the illuminating device by embodiment of this invention. The figure which shows the display part by the embodiment. (A) is a figure which shows the drive waveform (PWM signal waveform) output to the transistor corresponding to a shift position selection position, (b) is the drive waveform (PWM) output to the transistor corresponding to a shift position non-selection position. It is a figure which shows a signal waveform.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The case where the lighting device of the present invention is applied to an AT indicator that informs the AT shift position of a vehicle will be described as an example.

  FIG. 1 shows an illuminating device according to the present embodiment. The illuminating device 10 includes a light source 11, a transistor (switch means) 12, a limiting resistor 13, a control means 14, and a display unit 15 including an AT indicator. (See FIG. 2).

  The light source 11 includes a plurality of chip-type light emitting diodes (LEDs) that appropriately emit colors, and in this case, the light source 11 is provided so as to correspond to each indicator display unit described later of the display unit 15 (see FIG. 2). The light source 11 has an anode connected to the battery (power supply) Vb and a cathode connected to the collector of the transistor 12.

  The transistor 12 is an npn-type transistor, and is selectively turned on / off according to the AT shift position. A plurality of transistors 12 are provided for each indicator display section of the display section 15 (that is, for each light source 11). It is provided. In this case, the transistor 12 has a function as a constant current circuit in which the limiting resistor 13 is connected to the emitter side and the light source 11 (the cathode of the light source 11) is connected to the collector side. The base of the transistor 12 is connected to the output unit of the control means 14.

  The limiting resistor 13 is composed of a resistor element such as a chip resistor for adjusting (setting) the current value supplied to the light source 11, one end of which is connected to the emitter of the transistor 12, and the other end is connected to the ground level. Yes.

  The control means 14 is mainly composed of a microcomputer, and an input unit for inputting an input signal indicating that the AT shift position has been selected as a predetermined position by the user of the vehicle, and each transistor 12 based on the input signal. An input / output interface having an output port for outputting a drive waveform signal (PWM signal) whose pulse width is modulated at the same time, a CPU that executes a predetermined processing operation program, and a ROM that stores the processing operation program and the like. It is configured.

  As shown in FIG. 2, the display unit 15 includes indicator display units 15a, 15b, 15c, and 15d corresponding to the parking range “P”, the reverse range “R”, the neutral range “N”, and the drive range “D”, respectively. Thus, each light source 11 is arranged directly below each indicator display section 15a, 15b, 15c, 15d. The illuminating device 10 is comprised by the above each part.

  In the following description, the light source 11 corresponding to the indicator display unit 15a is the first light source L1, the light source 11 corresponding to the indicator display unit 15b is the second light source L2, and the light source 11 corresponding to the indicator display unit 15c. Is defined as a third light source L3, and the light source 11 corresponding to the indicator display unit 15d is defined as a fourth light source L4.

  The transistor 12 corresponding to the first light source L1 is the first transistor T1, the transistor 12 corresponding to the second light source L2 is the second transistor T2, and the transistor 12 corresponding to the third light source L3 is the third transistor. The transistor 12 corresponding to the transistor T3 and the fourth light source L4 is defined as a fourth transistor T4.

  Since the above-described illumination device 10 uses the display unit 15 as an AT indicator, any one of the light sources L1, L2, L3, and L4 corresponding to the indicator display units 15a, 15b, 15c, and 15d is turned on. It is the structure to do.

  Therefore, for example, when the input signal indicating that the drive range “D” is selected by the user of the vehicle is input to the control unit 14, the control unit 14 turns on all the individual transistors T 1 to T 4 in the transistor 12. A control signal (PWM signal) is output. Each of the transistors T1 to T4 receives the control signal and switches the individual transistors T1 to T4 to the on state.

  At this time, a PWM signal (hereinafter referred to as a first PWM signal) output from the control means 14 to the fourth transistor (predetermined transistor) T4 corresponding to the drive range “D” whose position is selected is: For example, as shown in FIG. 3A, the first duty ratio is about 90% (that is, a value obtained by multiplying the value calculated by the on time X1 / (on time X1 + off time X2) by 100 is about 90). Is set to

  Therefore, when the fourth transistor T4 is turned on, a predetermined constant current is supplied to the fourth light source (predetermined light source) L4 connected to the fourth transistor T4, and the drive range selected by this position is selected. The indicator display section 15d corresponding to “D” emits light, and the first PWM signal having the first duty ratio is output from the control means 14 to the fourth transistor T4. It becomes visible from the user side of the vehicle in a state where the indicator display unit 15d is brightly shining (emitted) at the first luminance.

  On the contrary, the control means 14 outputs the first to third transistors T1 to T3 corresponding to the parking range “P”, the reverse range “R”, and the neutral range “N” whose positions are not selected. For example, as shown in FIG. 3B, the PWM signal (hereinafter referred to as the second PWM signal) has a second duty ratio of about 3% (that is, an on time Y2 / (on time Y1 + off time). A value obtained by multiplying the value calculated in Y2) by 100 is set to about 3). That is, the second duty ratio is set to a value that is considerably smaller than the first duty ratio.

  Accordingly, when the first to third transistors T1 to T3 are turned on, the constant current is supplied to the first to third light sources L1 to L3, and thereby the parking range “P” whose position is not selected, The indicator display portions 15a to 15c corresponding to the reverse range “R” and the neutral range “N” emit light, and the first to third transistors T1 to T3 have the second duty ratio. When the PWM signal of 2 is output from the control means 14, the indicator display units 15a to 15c emit light (shine) at a second luminance lower (darker) than the first luminance. Visible from the side.

  That is, the second PWM signal output from the control unit 14 is the first to third light sources other than the fourth light source L4 at the second luminance lower than the first luminance. It becomes a signal component for the light sources L1 to L3 to shine.

  As described above, each of the transistors T1 to T4 causes the fourth light source L4 to shine at the first luminance among the light sources L1 to L4, and the other light sources L1 to L3 other than the fourth light source L4 are It has a function as a switching element for shining at a second luminance lower than the first luminance, and thus the vehicle user can display the display unit 15 (drive corresponding to the range selected by the AT shift). The indicator display unit 15d corresponding to the range “D” can be viewed brightly at the first brightness, and the other display units 15 (parking range “P”, reverse range “R”, neutral range “N”) are supported. Each indicator display unit 15a, 15b, 15c) can be visually recognized at a second luminance that is darker than the first luminance.

  According to this embodiment, when the fourth light source L4, which is a predetermined light source, is shining at the first luminance, the control unit 14 turns on the other light sources L1 to L3 other than the fourth light source L4. In order to shine at a second luminance lower than the first luminance, a fourth transistor T4, which is a predetermined transistor connected to the fourth light source L4 among the transistors T1 to T4, has the first duty cycle. The first PWM signal having a ratio is output, and the other transistors T1 to T3 other than the fourth transistor T4 have the second duty ratio set to a value smaller than the first duty ratio. Control for outputting the second PWM signal is performed.

  Therefore, the vehicle user can visually recognize the display unit selected by the AT shift and the other display units not selected by only the light sources L1 to L4 for illuminating the indicator display units 15a to 15d. Become. In addition, even at night or when the surroundings are dark, it is possible for the user to visually recognize the individual indicator display units. And since the exclusive light source and light guide are unnecessary like the past, there exists a merit that the structure of an illuminating device is simplified and cost reduction can be achieved.

  In this embodiment, the duty ratio of the first PWM signal output from the control unit 14 (that is, the first duty ratio) is set to about 90% and a value close to 100%, and from the control unit 14 Although an example in which the duty ratio of the second PWM signal to be output (that is, the second duty ratio) is set to about 3% has been described, the selected shift position is the first luminance. The first and second duty ratios can be set to any value as long as the shift position that is brilliant and dimly shines at the second luminance that is darker than the first luminance. Specifically, it is preferable that the first duty ratio is about 80% or more and the second duty ratio is about 10% or less.

DESCRIPTION OF SYMBOLS 10 Illuminating device 11 Light source 12 Transistor (switch means)
13 Limiting resistor 14 Control means 15 Display part L1 1st light source L2 2nd light source L3 3rd light source L4 4th light source T1 1st transistor T2 2nd transistor T3 3rd transistor T4 4th transistor

Claims (1)

A plurality of light sources;
A plurality of switch means provided for each of the light sources to shine a predetermined light source of the light sources at a first luminance;
Control means for outputting a drive waveform signal to each of the switch means based on a predetermined input signal,
The control means is configured to cause a light source other than the predetermined light source to shine at a second luminance lower than the first luminance when the predetermined light source shines at the first luminance. ,
The drive waveform signal having a first duty ratio is output to a predetermined switch unit connected to the predetermined light source among the switch units, and the first switch unit is switched to another switch unit other than the predetermined switch unit. An illuminating device comprising: the drive waveform signal having a second duty ratio set to a value smaller than the duty ratio.

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