JP5589451B2 - Lighting device - Google Patents

Description

  The present invention relates to an illumination device including a light emitter mounted on a circuit board and a member to be illuminated illuminated by illumination light from the light emitter.

  Conventionally, as for this kind of illuminating device, what is described in the following patent document 1, for example is known. The illuminating device described in Patent Document 1 is a light emitter including a circuit board on which a predetermined wiring pattern is formed and a single (one) LED mounted (arranged) on the wiring pattern (circuit board). And an illuminated member such as a liquid crystal display panel or a dial plate that is backlit by illumination light from the LED, and a synthetic resin material disposed between the circuit board and the illuminated member so as to surround the light emitter. A case body is provided.

JP 2004-151014 A

  By the way, in the illuminating device mentioned above, the design specification of changing the light emission luminance of a to-be-illuminated member, for example according to a vehicle model may exist. For example, in order to comply with a design specification that requires an increase in light emission luminance of a member to be illuminated, it is common to increase the number of LEDs (light emitters) mounted on a circuit board to a plurality instead of one. is there.

However, when dealing with the change in the design specification, the shape of the wiring pattern formed on the circuit board differs depending on whether the number of LEDs is one or more. The circuit board was separately designed and supported. Therefore, each time the number of LEDs mounted on the circuit board in the lighting device changes, a plurality of types of dedicated circuit boards are prepared, which not only complicates the circuit board design work, There is a problem in that the component management of the circuit board in the manufacturing process when manufacturing the lighting device becomes troublesome, and there is still room for further improvement in this respect.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an illuminating device that simplifies circuit board design and facilitates component management of the circuit board in order to address the above-described problems.

The present invention provides an illumination device including a light emitter disposed on a circuit board and a member to be illuminated illuminated by illumination light from the light emitter, wherein the light emitter includes the first light emitting element, A first connection land that allows connection of the light emitter and a power source; and the first light emitting element connected in series with the first light emitting element. A second connection land that enables connection between a predetermined portion of a wiring portion that connects the light emitting element and the second light emitting element and the power source is provided, and one of the first and second connection lands is provided. The first and second light-emitting elements are controlled to emit light by switching on / off states of the transistors, and the limiting resistor is provided on the first connection land. When implemented, the first and second When the current flowing through the first and second light emitting elements is adjusted by the limiting resistor so that the optical elements are turned on together, and the limiting resistor is mounted on the second connection land, the second light emission The current flowing through the first light emitting element is adjusted by the limiting resistor so that only the first light emitting element is lit without turning on the element .

  ADVANTAGE OF THE INVENTION According to this invention, the initial objective can be achieved, the design operation of a circuit board can be simplified, and the illuminating device which becomes easy to manage components of a circuit board can be provided.

Sectional drawing of the illuminating device by embodiment of this invention. The block diagram which shows the light-emitting body control circuit by the embodiment. FIG. 3 is a block diagram illustrating a light emitter control circuit when a limiting resistor is connected to a second connection land in FIG. 2.

  Hereinafter, an embodiment of a lighting device according to the present invention will be described with reference to FIGS. 1 and 2.

  As the lighting device according to the present embodiment, for example, a display unit incorporated in a part of a speedometer mounted on a vehicle can be applied, and the display unit D is a member to be illuminated as shown in FIG. The display 1, the two light emitters 2 disposed behind the display 1, the circuit board 3 on which the light emitter 2 is mounted, and the display 1 and the circuit board 3 so as to surround the light emitter 2. And a case body 4 disposed between the two.

  The display device 1 is composed of, for example, a liquid crystal display panel, and displays various information such as a mileage of the vehicle, fuel consumption, outside temperature, and time based on detection signals (electrical signals) from various sensors (not shown). (Not shown) for displaying information. The display 1 is backlit with illumination light from the light emitter 2.

  The light emitter 2 is composed of a chip-type light emitting diode (LED) that emits illumination light of an appropriate color, and is mounted (arranged) on the circuit board 3 on the back side of the display 1, and the front side (display 1 side). Is used to supply illumination light.

  The circuit board 3 is made of, for example, a hard circuit board in which a wiring pattern (not shown) is applied to a glass epoxy base material, and driving means (not shown) for driving and controlling the display 1, the light emitter 2, A light emitter control circuit, which will be described later, and various circuit components (not shown) such as a resistor and a capacitor are conductively connected to the wiring pattern.

  The case body 4 is made of, for example, white synthetic resin, and is positioned between the circuit board 3 and the display device 1 so as to surround the light emitting body 2 and has a function of holding the display device 1. If necessary, a diffusing plate is interposed between the case body 4 and the display 1, and the illuminating light emitted from the light emitter 2 is made substantially uniform by the diffusing plate. It is good also as a structure led to the indicator 1. In FIG. 1, reference numeral 5 denotes a dial of the speedometer, and the display 1 is arranged so as to face the opening 5 a provided in the dial 5.

  Next, a light emitter control circuit for lighting the light emitter 2 will be described with reference to FIG.

  Such a light emitter control circuit is provided on the circuit board 3, and as shown in FIG. 2, the control means 11, the transistor 12, the first light emitting element 13 which is one of the two light emitters 2 described above, The second light-emitting element 14, which is the other of the two light-emitting bodies 2 described above, a first connection land 15, and a second connection land 16 are provided. Further, the light emitter control circuit includes a limiting resistor 17 mounted on one of the first and second connection lands 15 and 16.

  For example, a microcomputer can be applied to the control means 11 and connected to a device such as a CAN (Controller Area Network) communication cable or an ignition switch. The control means 11 outputs a control signal for turning on the transistor 12 when receiving an ON operation signal for the headlamp switch of the vehicle, for example, by a user of the vehicle.

  The transistor 12 serves as switch means for controlling light emission of the light emitter 2 by switching the on / off state according to the control signal, and the collector side is connected to the cathode side of the first light emitting element 13. The emitter side is grounded to the ground level, and the base side is connected to the output section of the control means 11.

  The first light emitting element 13 is one of the two light emitters 2 described above, and the cathode side thereof is grounded to the ground level via the transistor 12.

  Further, when the limiting resistor 17 is mounted on the first connection land 15, the first light emitting element 13 is connected to the power source 18 on the anode side via the second light emitting element 14 and the limiting resistor 17. When 17 is mounted on the second connection land 16, the anode side is connected to the power source 18 through the limiting resistor 17 only.

  The second light emitting element 14 is the other of the two light emitters 2 described above, and is connected in series with the first light emitting element 13. The second light emitting element 14 has a cathode side connected to the anode side of the first light emitting element 13 and an anode side connected to one of the lands described later provided in the first connection land 15.

  The first connection land 15 is formed of a pair of lands that are pattern-printed in a shape in which the limiting resistor 17 can be mounted. When the limiting resistor 17 is mounted on the first connection land 15, the light emitter 2 (the light emitting elements 13 and 14) and the power source 18 are electrically connected via the limiting resistor 17. That is, in this case, the first connection land 15 has a function as a conductive portion for enabling the light emitter 2 (the light emitting elements 13 and 14) and the power source 18 to be electrically connected.

  The second connection land 16 includes a pair of lands that are pattern-printed in a shape in which the limiting resistor 17 can be mounted, and is parallel to the first connection land 15 at a position away from the position of the first connection land 15. Become connected.

  Here, the second connection land 16 in this example has a first light emitting element 13 (a cathode of the first light emitting element 13) and a second light emitting element 14 (an anode of the second light emitting element 14) on one side thereof. And the other side is connected to a power source 18. When the limiting resistor 17 is mounted on the second connecting land 16 instead of the first connecting land 15, the anode of the first light emitting element 13 and the power source 18 are electrically connected via the limiting resistor 17. The That is, in this case, the second connection land 16 has a function as a conductive portion for enabling the first light emitting element 13 (a predetermined portion of the wiring portion P) and the power source 18 to be conductively connected.

  The limiting resistor 17 is composed of a resistance element such as a chip resistor for adjusting the current supplied to the light emitter 2, and is selectively applied to either one of the first connection land 15 and the second connection land 16. It can be implemented in

  In this case, when the limiting resistor 17 is mounted on the first connection land 15, the limiting resistor 17 adjusts the current flowing through the first and second light emitting elements 13 and 14 and limits the current to the second connection land 16. When the resistor 17 is mounted, the limiting resistor 17 adjusts the current flowing through the first light emitting element 13. Needless to say, when the limiting resistor 17 is mounted on the second connection land 16, no current flows through the second light emitting element 14.

  When the limiting resistor 17 is mounted on the first connection land 15, the power source 18 is connected to the first and second light emitting elements 13 and 14 via the limiting resistor 17. At this time, when the ON operation signal is input to the control unit 11, the control unit 11 outputs a control signal for turning on the transistor 12.

  In response to this control signal, the transistor 12 switches the transistor 12 to the on state, and accordingly, the first and second light emitting elements 13 and 14 connected to the power source 18 through the limiting resistor 17 have certain constants. By supplying the current value, the first and second light emitting elements 13 and 14 are turned on, and the display 1 is backlit. That is, this means that when the limiting resistor 17 is mounted on the first connection land 15, both the first and second light emitting elements 13 and 14 are lit.

  On the other hand, when the limiting resistor 17 is mounted not on the first connecting land 15 but on the second connecting land 16 as shown in FIG. 3, the power source 18 is connected only to the first light emitting element 13 via the limiting resistor 17. Connected to. At this time, when the ON operation signal is input to the control means 11 and the transistor 12 is switched to the ON state, the first light emitting element 13 connected to the power source 18 through the limiting resistor 17 has a certain current value. Is supplied, the first light emitting element 13 is turned on and the display 1 is backlit. In other words, this means that when the limiting resistor 17 is mounted not on the first connection land 15 but on the second connection land 16, only the first light emitting element 13 is turned on without turning on the second light emitting element 14. Is meant to do.

  As described above, in the present embodiment, in the illumination device including the light emitter 2 mounted on the circuit board 3 and the display device 1 illuminated by the illumination light from the light emitter 2, the light emitter 2 is the first. The light emitting element 13 and the second light emitting element 14 connected in series with the first light emitting element 13, and the circuit board 3 includes a light emitter 2 (each light emitting element 13, 14) and a power source 18. A first connection land 15 that can be connected, and a second connection land 16 that can connect a power source 18 to a predetermined portion of the wiring portion P that connects the first light emitting element 13 and the second light emitting element 14. And the limiting resistor 17 can be mounted on any one of the first and second connection lands 15 and 16. When the limiting resistor 17 is mounted on the first connection land 15, both the first and second light emitting elements 13 and 14 are lit, and when the limiting resistor 17 is mounted on the second connection land 16, the second is connected. Only the first light-emitting element 13 is lit without the light-emitting element 14 being lit.

  Accordingly, when the design specification is required to increase the emission luminance of the illuminated member 1, the limiting resistor 17 is mounted on the first connection land 15 and a plurality of LEDs (that is, the first and second light emission). In the case where the elements 13 and 14) are turned on and, on the other hand, the design specification does not require the brightness increase, the limiting resistor 17 is mounted not on the first connection land 15 but on the second connection land 16 to provide a single LED. Since only the first light-emitting element 13 needs to be turned on, it is not necessary to separately design and deal with a dedicated circuit board for each design specification as in the prior art. The work is simplified, and circuit board component management can be easily performed in the manufacturing process when the display unit D (illumination device) is manufactured.

  In the present embodiment, the example in which the second light emitting element 14 is formed of a single LED has been described. However, the number of the second light emitting elements 14 is not limited to one but may be plural. For example, in FIG. 2, there are a plurality of wirings between the first connection land 15 and the wiring connection portion C, which is a connection portion between the wiring pattern H extending from one land of the second connection land 16 and the wiring portion P. It is good also as a structure which connects the 2nd light emitting element 14 in series.

1 Display (illuminated member)
DESCRIPTION OF SYMBOLS 2 Light-emitting body 3 Circuit board 4 Case body 5 Dial 11 Control means 12 Transistor 13 1st light emitting element 14 2nd light emitting element 15 1st connection land 16 2nd connection land 17 Limiting resistor 18 Power supply P Wiring part

Claims (1)

In an illuminating device including a light emitter disposed on a circuit board, and a member to be illuminated illuminated by illumination light from the light emitter,
The light emitter includes a first light emitting element and at least one second light emitting element connected in series with the first light emitting element,
The circuit board includes a first connection land that allows the light emitter and a power source to be connected, a predetermined portion of a wiring portion that connects the first light emitting element and the second light emitting element, and the power source. A second connection land that is connectable,
A configuration in which a limiting resistor can be mounted on any one of the first and second connection lands ,
The first and second light emitting elements are controlled to emit light by switching the on / off state of the transistor, and
When the limiting resistor is mounted on the first connection land, the current flowing through the first and second light emitting elements is adjusted by the limiting resistor so that both the first and second light emitting elements are lit. And
When the limiting resistor is mounted on the second connection land, the first light emitting element is driven by the limiting resistor so that only the first light emitting element is lit without turning on the second light emitting element. The lighting device is characterized in that the current flowing through is adjusted .

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