LED bulb

Abstract

To provide an LED bulb 1 having high versatility and capable of obtaining a color rendering effect with a simple structure.SOLUTION: An LED bulb 1 includes: a white color LED 4a; a blue color LED 4b; a base portion 2a that energizes the white LED 4a and the blue LED 4b from an external socket; and a control circuit 5 that controls luminance of each of the white LED 4a and the blue LED 4b. Until a first predetermined time t1 from when a voltage is applied through the base portion 2a, the control circuit 5 causes the blue LED 4b to emit light at a luminance value of 100% of a luminance value obtained in normal lighting and causes the white LED 4a not to emit light; while decreasing luminance of the blue LED 4b over time from the first predetermined time t1 to a second predetermined time t2, the control circuit causes the white LED 4a to emit light so that luminance of the white LED 4a increases from a luminance value of 0% over time; after the second predetermined time t2 has elapsed, the control circuit causes the blue LED 4a not to emit light and causes the white LED 4a to emit light at 100% of a luminance value obtained in normal lighting.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This disclosure relates to LED bulbs.

Background Art

[0002] Conventionally, as lighting devices installed in automobiles, there are room lamps installed on the roof or the like inside the vehicle cabin, or door courtesy lamps installed on the doors. In this type of lighting device, in addition to the original lighting function, there are some that expect a color rendering effect such as producing a sense of luxury.

[0003] Patent Document 1 discloses a technique related to a lighting device that enhances the color rendering effect by using a first light source composed of an LED (light-emitting diode) with a colored emission color and a second light source composed of an LED with a white emission color. In this lighting device, starting from when any door is opened, the first light source lights up so that the light intensity gradually increases at the initial stage of lighting. Next, when a predetermined time has elapsed since the start of lighting of the first light source and the light intensity of the first light source is gradually increasing, the second light source lights up so that the light intensity gradually increases at the initial stage of lighting. Then, when all doors are closed, the second light source goes out so that the light intensity gradually decreases, and when a predetermined time has elapsed since the start of extinguishing of the second light source and the light intensity of the second light source is gradually decreasing, the first light source goes out so that the light intensity gradually decreases.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] While the lighting device disclosed in Patent Document 1 can achieve a complex color rendering effect by combining changes in illuminance and color tone, it also complicates the control mechanism and may require additional mechanisms such as a switch for manually turning the lights on and off. As a result, such lighting devices are expected to be structurally complex or large, potentially leading to increased costs or making it difficult to apply them to various vehicle types.

[0006] Therefore, the purpose of this disclosure is to provide an LED bulb that is highly versatile, has a simple structure, and can achieve a color rendering effect. [Means for solving the problem]

[0007] An LED bulb according to one aspect of the present disclosure comprises a white LED, a blue LED, a base portion connected to an external socket and through which power is supplied to the white LED and the blue LED from the socket, and a control circuit for controlling the brightness of the white LED and the blue LED, wherein the control circuit illuminates the blue LED at 100% of its normal brightness value and does not illuminate the white LED from the time voltage is applied through the base portion until a first predetermined time, and does not illuminate the white LED, and from the first predetermined time until a second predetermined time, the brightness of the blue LED is decreased in accordance with the passage of time while the brightness of the white LED is illuminated so that the brightness of the white LED increases from a brightness value of 0% in accordance with the passage of time, and after the second predetermined time has elapsed, the blue LED is turned off and the white LED is illuminated at 100% of its normal brightness value. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide an LED bulb that is highly versatile, has a simple structure, and can achieve a color rendering effect. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view showing a first example of an LED bulb according to one embodiment. [Figure 2] This graph shows an example of brightness control for each LED. [Figure 3]This is a perspective view showing a second example of an LED bulb according to one embodiment. [Modes for carrying out the invention]

[0010] The following describes exemplary embodiments with reference to the drawings. The dimensions, materials, and other specific numerical values ​​shown in these embodiments are illustrative only and, unless otherwise specified, do not limit this disclosure. Furthermore, elements having substantially the same function and configuration are denoted by the same reference numerals to avoid redundant explanations, and elements not directly related to this disclosure are omitted from the illustrations.

[0011] Figure 1 is a perspective view showing an LED bulb 1 according to one embodiment. The LED bulb 1 can be used, for example, as an interior lamp such as a dome lamp, courtesy lamp, or luggage lamp installed in the passenger compartment of an automobile. Furthermore, as a first example of the LED bulb according to this embodiment, the LED bulb 1 conforms to the T10 wedge bulb standard, which is a common standard for automotive lamps.

[0012] The LED bulb 1 comprises a shaft portion 2, a base portion 2a, a head portion 3, a plurality of LEDs 4, and a control circuit 5.

[0013] The shaft portion 2, together with the head portion 3, constitutes the main body of the LED bulb 1. The material of the shaft portion 2 and the head portion 3 is, for example, an aluminum alloy, but is not particularly limited. A base portion 2a is provided separately at one end of the shaft portion 2. The base portion 2a is the part that connects to an external socket, is made of a non-conductive material such as resin, and includes two outer lead wires 6 that serve as electrical contacts with the socket. The shape and configuration of the base portion 2a conform to the standard for T10 wedge bulbs.

[0014] Furthermore, a head 3 is attached to the shaft end 2 on the side opposite to the side where the socket 2a is provided. The shaft 2 includes a housing (not shown) that houses the control circuit 5. An operator can remove the head 3 from the shaft 2 and house the control circuit 5 in the housing inside the shaft 2. Note that the combination of the shaft 2 and the head 3 is just one example of the configuration of the main body of the LED bulb 1. For example, the shaft 2 may have a removable socket 2a, and the control circuit 5 may be housed in the housing of the shaft 2 from the side of the shaft end to which the socket 2a is connected.

[0015] Furthermore, the shaft portion 2 has multiple first mounting portions 2b on its outer circumference for installing the LEDs 4. In the example of the LED bulb 1, four LEDs 4 are installed on the shaft portion 2, so four first mounting portions 2b are provided on the outer circumference of the shaft portion 2 at equal intervals in the circumferential direction. Note that in Figure 1, due to the nature of the perspective view, two first mounting portions 2b are visible, while the other two first mounting portions 2b are not.

[0016] The head portion 3 is a cover portion that is attached to the shaft portion 2. The head portion 3 is made of a non-conductive material such as resin. The head portion 3 has a second mounting portion 3a on the side opposite to the side attached to the shaft portion 2 for installing the LED 4. In this embodiment, one LED 4 is installed in the second mounting portion 3a along the axial direction of the shaft portion 2 and facing away from the side where the base portion 2a is provided.

[0017] Each set of LEDs 4 includes at least one white LED 4a and at least one blue LED 4b. In the example of LED bulb 1, a total of five LEDs 4 are installed: four on the shaft 2 and one on the head 3. Of the five LEDs 4, one of the four LEDs 4 installed on the shaft 2 is a blue LED 4b. In other words, the four LEDs 4 other than the blue LED 4b are white LEDs 4a.

[0018] In addition, regarding the number of LEDs 4 installed in the LED bulb 1, as long as at least one white LED 4a and at least one blue LED 4b are included, any number of two or more is acceptable. Also, as in this embodiment, even when the LED bulb 1 installs five LEDs 4, the number of blue LEDs 4b may be two or more, or the LED 4 installed in the head 3 may be the blue LED 4b.

[0019] The control circuit 5 controls the brightness of each of the white LED 4a and the blue LED 4b. That is, the control circuit 5 conducts to all of the plurality of LEDs 4 and also conducts to the outer lead wire 6 of the base portion 2a.

[0020] FIG. 2 is a graph showing an example of the brightness control of the white LED 4a and the blue LED 4b in the control circuit 5.

[0021] Here, it is assumed that the LED bulb 1 is connected to a socket such as a dome lamp previously installed in the vehicle interior. Also, it is assumed that when a lighting instruction for a dome lamp or the like using the LED bulb 1 is given from the vehicle body circuit side, a voltage is applied to the LED bulb 1 through the base portion 2a. Hereinafter, the time when the voltage is applied is taken as the initial time t0.

[0022] First, from the initial time t0 to the first predetermined time t1, the control circuit 5 lights the blue LED 4b at 100% of the brightness value during normal lighting and does not light the white LED 4a. The first predetermined time t1 is, for example, 3 seconds from the initial time t0.

[0023] Next, from the first predetermined time t1 to the second predetermined time t2, while reducing the brightness of the blue LED 4b in accordance with the passage of time, the control circuit 5 lights the white LED 4a so that the brightness of the white LED 4a increases from a brightness value of 0% in accordance with the passage of time. The second predetermined time t2 is, for example, 5 seconds from the initial time t0.

[0024] Then, after the second predetermined time t2 has elapsed, the control circuit 5 turns off the blue LED 4b and lights up the white LED 4a at 100% of its normal brightness value.

[0025] Next, I will explain the effects of LED bulb 1.

[0026] The LED bulb 1 comprises a white LED 4a, a blue LED 4b, a base portion 2a connected to an external socket and through which power is supplied to the white LED 4a and blue LED 4b, and a control circuit 5 that controls the brightness of the white LED 4a and blue LED 4b. The control circuit 5 lights the blue LED 4b at 100% of its normal brightness value and does not light the white LED 4a from the time voltage is applied through the base portion 2a until a first predetermined time t1. From the first predetermined time t1 to the second predetermined time t2, the control circuit 5 lights the white LED 4a so that the brightness of the blue LED 4b decreases over time, while the brightness of the white LED 4a increases from 0% over time. After the second predetermined time t2 has elapsed, the control circuit 5 turns off the blue LED 4b and lights the white LED 4a at 100% of its normal brightness value.

[0027] First, when the vehicle's circuitry issues a signal to the LED bulb 1 used in the interior lights, etc., the LED bulb 1 initially lights up in blue. Then, as time passes, the color of the LED bulb 1 gradually fades from blue to white, and after a second predetermined time t2, the blue light completely switches to white. In other words, although the normal color of the LED bulb 1 is white light, when the interior lights, etc. are turned on, the color of the light does not start out white, but gradually changes from blue to white, providing a color rendering effect.

[0028] Furthermore, the color rendering effect of the LED bulb 1 is easily achieved by the control circuit 5 located within the LED bulb 1, which individually controls the brightness of multiple LEDs 4. In other words, the color rendering effect of the LED bulb 1 is obtained solely as a result of the configuration of the LED bulb 1 itself. Therefore, there is no need to separately install a switch or the like on the vehicle body to switch the light emission settings as needed. Also, since the shape or configuration of the LED bulb 1 can conform to generally adopted standards, the LED bulb 1 is highly versatile. Consequently, users can easily obtain the color rendering effect simply by replacing the bulbs previously used in interior lights, etc., with the LED bulb 1.

[0029] Thus, according to this embodiment, it is possible to provide an LED bulb 1 that is highly versatile and can achieve a color rendering effect with a simple structure.

[0030] Furthermore, in the LED bulb 1, the first predetermined time t1 is a time period of 2 seconds or more and less than 4 seconds from the time the voltage is applied, and the second predetermined time t2 may be a time period of 1 second or more and less than 4 seconds from the first predetermined time t1.

[0031] With this LED bulb 1, when the room lamp or other lights using this LED bulb 1 are turned on, occupants are more likely to perceive the color rendering effect.

[0032] Furthermore, in the LED bulb 1, the first predetermined time t1 may be 3 seconds from the time the voltage is applied, and the second predetermined time t2 may be 5 seconds from the time the voltage is applied.

[0033] With this LED bulb 1, when the room lamp or other lights using this LED bulb 1 are turned on, occupants are more likely to perceive a color rendering effect.

[0034] Up to this point, we have illustrated the case where the first example LED bulb 1 is compatible with a T10 wedge bulb. In contrast, the LED bulb according to this embodiment is not limited to cases that conform to the said standard. For example, it can also be used in the following types of LED bulbs.

[0035] Figure 3 is a perspective view showing an LED bulb 10 according to one embodiment. As a second example of the LED bulb according to this embodiment, the LED bulb 10 conforms to the T10×31 boat-shaped bulb standard of general automotive lamps. Such an LED bulb 10 can also be used as an interior lamp such as a dome lamp, courtesy lamp, or luggage lamp, installed in the passenger compartment of an automobile or the like.

[0036] The LED bulb 10 comprises a shaft portion 12, a transparent cover 13, a plurality of LEDs 14, a control circuit 15, and a base portion 16.

[0037] The shaft portion 12 constitutes the main body of the LED bulb 10. The material of the shaft portion 12 is, for example, an aluminum alloy, but is not particularly limited. The shaft portion 12 is semi-cylindrical and includes a housing portion (not shown) that houses the control circuit 15 inside. Both ends of the shaft portion 12 are provided with socket portions 16 that conform to the T10×31 boat-shaped bulb standard. The shaft portion 12 also has an installation portion 12a on its inner surface for installing the LED 14.

[0038] The transparent cover 13 covers the mounting section 12a on which multiple LEDs 14 are installed, and is semi-cylindrical in shape with an outer diameter that matches the outer diameter of the shaft section 12. The transparent cover 13 protects the LEDs 14 while allowing the light emitted from the LEDs 14 to pass through to the outside.

[0039] Each set of LEDs 14 includes at least one white LED 14a and at least one blue LED 14b. In the example of the LED bulb 10, three LEDs 14 are installed in the mounting section 12a. Of the three LEDs 14, two are white LEDs 14a and one is a blue LED 14b.

[0040] Furthermore, in the LED bulb 10, the number of LEDs 14 installed can be two or more, as long as it includes at least one white LED 4a and at least one blue LED 4b.

[0041] The control circuit 15 controls the brightness of the white LED 14a and the blue LED 14b. In other words, the control circuit 15 is electrically connected to all of the LEDs 14 and also to the base portion 16. The control circuit 15 then controls the brightness of the white LED 14a and the blue LED 14b, similar to the control circuit 5 of the LED bulb 1 as the first example, thereby achieving the same effect as the LED bulb 1.

[0042] Although embodiments have been described above, it is possible to modify or transform the embodiments based on the above disclosure. All components of the above embodiments, and all features described in the claims, may be individually selected and combined, provided that they do not contradict each other. [Explanation of Symbols]

[0043] 1.10 LED bulbs 2a,16 Mouthpiece 4a,14a white LED 4b,14b Blue LED 5.15 Control circuit

Claims

1. White LED (light-emitting diode), Blue LED and A base portion connected to an external socket, through which power is supplied to the white LED and the blue LED from the socket, The system includes a control circuit for controlling the brightness of the white LED and the blue LED, respectively. The aforementioned control circuit is From the time a voltage is applied through the base portion until a first predetermined time, the blue LED is lit at 100% of its normal brightness value, and the white LED is not lit. From the first predetermined time to the second predetermined time, the brightness of the blue LED is decreased in accordance with the passage of time, while the brightness of the white LED is turned on so that the brightness of the white LED increases from 0% in accordance with the passage of time. After the second predetermined time has elapsed, the blue LED is turned off, and the white LED is turned on at 100% of its normal brightness value. The first predetermined time is a period of time ranging from 2 seconds to less than 4 seconds from the time the voltage is applied. The LED bulb wherein the second predetermined time is a time within the range of 1 second or more and less than 4 seconds from the first predetermined time.

2. The first predetermined time is 3 seconds from the time the voltage is applied. The LED bulb according to claim 1, wherein the second predetermined time is 5 seconds from the time the voltage is applied.

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