WO2008084901A1

WO2008084901A1 - Street lamp

Info

Publication number: WO2008084901A1
Application number: PCT/KR2007/003607
Authority: WO
Inventors: Soo-Jo Park
Original assignee: Kang, Gey-Won
Priority date: 2007-01-11
Filing date: 2007-07-26
Publication date: 2008-07-17
Also published as: KR20080066112A

Abstract

The present invention relates to a streetlamp, and includes an illumination unit (100) including a plurality of CCFLs (110), a conversion unit (200) including an SMPS (210) to convert a voltage level of commercial power into a voltage level used for the illumination unit (100), a heating unit (300) installed adjacent to the SMPS, a control unit (400) for controlling lighting of the illumination unit and ON-OFF operation of the heating unit, and a case (500) for accommodating the illumination unit, the conversion unit, and the heating unit. The present invention, having the above construction, is advantageous in that the operating environment of the SMPS is controlled, so that the SMPS can be operated in the summer and winter seasons and in outdoor places, and thus the discharge of CCFLs is possible.

Description

Description STREET LAMP

Technical Field

[1] The present invention relates, in general, to streetlamps, and, more particularly, to a streetlamp, in which the operating environment of a switching-mode power supply is controlled, thus enabling the streetlamp to be used in the summer and winter seasons and in outdoor places. Background Art

[2] Generally, as shown in FIG. 1, a streetlamp structure 1, installed on the roadside, includes streetlamps 3 having lamps 3a mounted therein, supports 4 configured to support the streetlamps 3, and a lamp post 3 configured to be erected on the ground and to be coupled and combined with the supports 4, which support the streetlamps 3, and operated to turn on the lamps 3a using commercial AC power as a power source.

[3] In detail, the streetlamp structure turns on the lamps 3a, such as mercury lamps or sodium lamps, through the use of a timer (not shown) for supplying power to the lamps 3a so as to turn on the lamps for a predetermined period of time using commercial AC power as a power source, and a central processing unit (not shown) for supplying power so as to simultaneously turn on or off the lamps at designated time points, thus illuminating the roadside.

[4] However, the conventional streetlamps 3 are problematic in that, since the lifespan of the lamps 3a is shortened, high management costs and maintenance costs are required, in that, since externally applied commercial AC power is used as a power source, power consumption is increased, and in that, since it is difficult to change the illumination status in response to various types of weather conditions and surrounding environments, such as lighting times, optimal illumination status cannot be maintained, thus making it difficult to reduce the power consumption of the streetlamps 3.

[5] In order to solve the above problem, a streetlamp in which a Cold Cathode

Fluorescent Lamp (CCFL) or an External Electrode Florescent Lamp (EEFL) is mounted has recently been used.

[6] The CCFL or EEFL is a lamp which is not provided with a discharge filament, and is formed in such a way that fluorescent material is applied on the inner surface of a glass tube, electrodes are attached to both ends of the glass tube, noble gases and an exact amount of mercury are inserted into a lamp, and the lamp is sealed. The CCFL or EEFL is operated such that, when high voltage is applied to both ends of the lamp, electrons present in the glass tube are induced to the electrodes at high speed, and the discharge of the lamp is initiated due to secondary electrons generated through the collision between the electrodes and the electrons.

[7] However, since high voltage must be applied in order to initiate the discharge of the lamp, commercial AC power is transmitted to a control unit via an inverter through an interposed Switching-Mode Power Supply (SMPS), and thus high voltage is applied to the lamp. At this time, since the SMPS is operated only when conditions corresponding to a temperature of about 10 to 5O⁰C and a humidity of about 30 to 85% are met, the operability thereof is remarkably decreased in outdoor places. Especially in the winter season, when the temperature decreases below 1O⁰C, and in the summer season (the wet season or the rainy season), when the humidity is very high, the SMPS cannot be operated, and thus there is a problem in that the lamp of the streetlamp is not actually discharged.

Disclosure of Invention Technical Problem

[8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a streetlamp, in which the operating environment of a switching-mode power supply can be controlled, thus enabling the streetlamp to be smoothly used in the summer and winter seasons and in outdoor places, and which can control the lighting of respective illumination lamps and can efficiently maintain illumination status, thus reducing power consumption. Technical Solution

[9] In order to accomplish the above object, the present invention provides a streetlamp, comprising an illumination unit including a plurality of Cold Cathode Fluorescent Lamps (CCFLs); a conversion unit including a Switching-Mode Power Supply (SMPS) to convert a voltage level of commercial power into a voltage level used for the illumination unit; a heating unit installed adjacent to the SMPS; a control unit for controlling lighting of the illumination unit and ON-OFF operation of the heating unit; and a case for accommodating the illumination unit, the conversion unit, and the heating unit.

[10] Preferably, the heating unit may comprise a temperature sensor for sensing a temperature of the SMPS, and may be operated such that, when heating is performed at a temperature higher than an operating temperature of the SMPS, the control unit performs a control operation to turn off the heating unit.

[11] Preferably, the control unit may comprise illuminance control means for controlling

ON-OFF operation of all of the CCFLs of the illumination unit depending on an illuminance sensed by an illuminance sensor.

[12] Preferably, the control unit may comprise timer control means for performing a control operation such that the CCFLs of the illumination unit switch from a fully ON- state to a partially ON-state on a basis of a set time point.

[13] Preferably, the control unit may comprise human body sensing control means for performing a control operation such that the CCFLs of the illumination unit switch from a partially ON-state to a fully ON-state for a predetermined period of time when an approach of a pedestrian is sensed.

Advantageous Effects

[14] The present invention controls the operating environments of a Switching-Mode

Power Supply (SMPS), so that the SMPS can be operated to discharge lamps in the summer and winter seasons and in outdoor places, thus enabling a streetlamp to be used in the summer and winter seasons and in outdoor places. [15] Further, the present invention is advantageous in that it enables the control of lighting of respective illumination lamps, so that lighting status can be efficiently maintained, and thus the power consumption of the streetlamp can be reduced.

Brief Description of the Drawings

[16] FIG. 1 is a perspective view of a typical streetlamp structure;

[17] FIG. 2 is a bottom view showing the construction of the illumination unit of a streetlamp according to an embodiment of the present invention; and [18] FIG. 3 is a block diagram showing the construction of a streetlamp according to an embodiment of the present invention.

[19] <Description of reference characters of important parts>

[20] 10: lamp post 20: support

[21] 30: streetlamp 100: illumination unit

[22] 110: Cold Cathode Fluorescent Lamp (CCFL) 200: conversion unit

[23] 210: Switching-Mode Power Supply (SMPS) 220: inverter

[24] 300: heating unit 302: hot wire

[25] 304: heating plate 310: temperature sensor

[26] 400: control unit 410: illuminance control means

[27] 420: timer control means 430: human body sensing control means

[28] 500: case

Best Mode for Carrying Out the Invention [29] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. [30] As shown in FIGS. 3 and 5, a streetlamp 30 according to an embodiment of the present invention includes an illumination unit 100, a conversion unit 200, a heating unit 300, a control unit 400, and a case 500. [31] The illumination unit 100 includes a plurality of Cold Cathode Fluorescent Lamps (CCFLs) 110 for illuminating a roadside, and is mounted in the case 500 coupled to a support (20 of FIG. 2) provided on the upper portion of a lamp post (10 of FIG. 2).

[32] The conversion unit 200 is a component that includes a Switching-Mode Power supply (SMPS) 210 and an inverter 220, and that operates to convert the voltage level of commercial AC power to the voltage level used for the CCFLs 110 of the illumination unit 100, and to supply the converted voltage.

[33] The heating unit 300 is a component installed adjacent to the above-described

SMPS 210 and configured to perform heating in order to supply a heat source so that the operating environment of the SMPS 210 can be controlled.

[34] The control unit 400 is a component for controlling the lighting of the CCFLs 110 of the illumination unit 100 and controlling the heating temperature of the heating unit 300.

[35] The case 500 is a component for accommodating the illumination unit 100, the conversion unit 200, and the heating unit 300, and may also accommodate the control unit 400.

[36] First, the illumination unit 100 is described in detail below.

[37] As shown in FIG. 3, the illumination unit 100 is formed in such a way that a plurality of CCFLs 110 is mounted in a center portion inside the case 500, and is configured to include CCFLs 110 capable of providing several advantages, such as long lifespan and high illuminance, thus being able to illuminate roadways and paths.

[38] Since the CCFLs 110 have a supply voltage of 12V, a power consumption of about

3.9W/hr, luminance of about 38,000D/D, and a lifespan of about 35,000hr, they have excellent lamp performance, such as supply voltage, power consumption, luminance and lifespan, compared to typical streetlamps, such as mercury lamps or sodium lamps, thus reducing energy consumption by 60 to 80%.

[39] Meanwhile, instead of the above-described CCFLs 110, External Electrode

Florescent Lamps (EEFLs) can be used, and, hereinafter, the term "CCFL" is to be understood to include both "CCFL" and "EEFL".

[40] Next, the conversion unit 200 is described in detail below.

[41] The conversion unit 200 is a component for converting the voltage level of commercial AC power into the voltage level used for the CCFLs 110 of the illumination unit 100 and supplying the converted voltage, and includes the SMPS 210 and the inverter 220, as shown in FIG. 3.

[42] In order to convert the voltage level of commercial AC power into the voltage level used for the CCFLs 110, a voltage of 220V, which is the commercial AC power, is converted into a DC voltage from 12 to 14V through the SMPS 210, and the DC voltage from 12 to 14V is formed as a high voltage from 700 to 1000V through the inverter 220. [43] The CCFLs 110 of the illumination unit 100 are discharged using the high voltage from 700 to 1000V formed in this way.

[44] Next, the heating unit 300 is described in detail below.

[45] As shown in FIG. 3, the heating unit 300 is installed adjacent to the SMPS 210 so as to control the operating environments of the SMPS 210, and is operated when the temperature of the SMPS 210 decreases below an operating temperature or when the humidity thereof increases, thus increasing the temperature and spontaneously eliminating humidity due to the increase in temperature.

[46] In other words, the SMPS 210 and the heating unit 300 are installed to be disposed in the space inside the case 500, which will be described later. In the winter season, in which the temperature decreases below 1O⁰C, the temperature of the space inside the case 500 also decreases below 1O⁰C, and thus deviates from the range of the operating temperature of the SMPS 210. In this case, the heating unit 300 installed adjacent to the SMPS 210 is operated to increase the temperature of the space inside the case 500 and the temperature of the SMPS 210, and thus meets the operating range of the SMPS 210, that is, a temperature range from 10 to 5O⁰C.

[47] Further, in the summer season (wet season or rainy season), humidity frequently increases. In this case, the heating unit 300 is operated to increase the temperature in the space inside the case 500, and thus the internal humidity of the case 500 is eliminated. Accordingly, a humidity of about 30 to 85%, at which the SMPS 210 is operated, can be satisfied.

[48] Meanwhile, in the winter season and summer season (wet or rainy season), the operating environments of the SMPS 210 are controlled by operating the heating unit 310 in advance before the CCFLs 110 are turned on, thus enabling the discharge of the CCFLs 110 of the illumination unit 100.

[49] The above-described heating unit 300 can be implemented using a fixed temperature heating element, the internal resistance of which varies with temperature, or using a typical heating element, but, in this case, a temperature controller capable of controlling temperature is installed and used.

[50] In the streetlamp 30 according to this embodiment, the heating unit 300 is implemented using a resistance heating method, in which a hot wire 302 is arranged in a heating plate 304 to cause current to flow through the hot wire, as shown in FIG. 4, and is installed adjacent to the SMPS 210. Before the CCFLs 110 are discharged, current is caused to flow through the hot wire 302 for a predetermined period of time, thereby heating the heating plate 304. Accordingly, the temperature of the space inside the case 500 and the temperature of the SMPS 210 are increased, thus realizing an operating temperature and an operating humidity suitable for the SMPS 210.

[51] Meanwhile, in order to prevent overheating from occurring due to the excessive increase in the temperature of the heating plate 304 while current flows through the hot wire 302 to heat the heating plate 304 for a predetermined period of time, a temperature sensor (310 of FIG. 5) is provided in a predetermined portion of the heating plate 304, so that the control unit 400 senses the temperature through the temperature sensor 310, and performs a control operation to turn off the heating unit 300 if the sensed temperature becomes greater than a preset temperature, thus preventing the heating unit from overheating.

[52] It will be apparent that, in addition to the above-described method of controlling the operation of the heating unit 300 using the temperature sensor 310, a temperature control method, such as a method using a bimetal, can be selectively used.

[53] Next, the control unit 400 is described in detail below.

[54] As described above, the control unit 400 is a component for controlling the lighting of respective CCFLs 110 of the illumination unit 100 in response to temporal conditions, such as daytime and nighttime, weather conditions, and various other types of surrounding environmental conditions, in addition to controlling the operation of the heating unit 300. As shown in FIG. 5, the control unit 400 includes an illuminance control means 410, a timer control means 420, and a human body sensing control means 430, and controls the lighting of the CCFLs 110 of the illumination unit 100 depending on the illuminance, set time points, and the presence of a pedestrian.

[55] The illuminance control means 410 controls the ON or OFF operation of all of the

CCFLs 110 of the illumination unit 100 depending on the illuminance sensed by an illuminance sensor (410a of FIG. 5) installed on a portion of the streetlamp 30 or the lamp post 10. Therefore, the illuminance control means 410 performs a control operation so that, when the illuminance, sensed by the illuminance sensor 410a, is lower than a predetermined reference value, the illumination unit 100 is turned on, whereas, when the sensed illuminance is higher than the predetermined reference value, the illumination unit 100 is turned off.

[56] The control of the lighting of the illumination unit 100 using the illuminance control means 410 allows human beings to control lighting with reduced effort, thus reducing personal expenses, and turns on the illumination unit 100 in a dark state attributable to the weather, even in the daytime, thus maintaining optimal streetlamp illumination status.

[57] The timer control means 420 sets a predetermined lighting time point in a timer (not shown), and performs a control operation to switch the plurality of CCFLs 110 of the illumination unit 100 from a fully ON-state to a partially ON-state on the basis of the set time point.

[58] For example, since, at night, few vehicles or pedestrians travel along a street, only some of the CCFLs of the illumination unit 100 are turned on by the timer, and thus the power consumption of the streetlamp can be reduced.

[59] The human body sensing control means 430 performs a control operation so that, when a human body sensor (430a of FIG. 5) installed on a portion of the lamp post senses the approach of a pedestrian, the CCFLs 110 of the illumination unit 100 switch from a partially ON-state to a fully ON-state for a preset period of time.

[60] That is, when few pedestrians travel along a street at night, the human body sensor

430a senses the passing of a pedestrian while only some of the CCFLs 110 of the illumination unit 100 are turned on, so that all of the CCFLs 110 of the illumination unit 100 are turned on for a predetermined period of time, thus enabling optimal streetlamp illumination status to be maintained depending on whether a pedestrian travels along a street.

[61] The human body sensor 430a can be implemented using, for example, a sensing means using ultrasonic waves or a micro switch, or a sensing means using an infrared detection method. In the case of the infrared detection method, infrared energy emitted from a human body is collected and converted into an electrical signal, and the electrical signal is amplified to a signal that can be processed and is applied to the control unit 400.

[62] This embodiment has been described so that the illuminance control means 410, the timer control means 420 and the human body sensing control means 430 are provided as separate means, and are included in the control unit 400, but represents functional classification based on functions, and it will be apparent that the actual application forms can be variously realized according to the detailed method in which the control unit 400 is constructed.

[63] Finally, as shown in FIG. 2, the case 500 is a component that is coupled to the support 20 provided on the upper portion of the lamp post 10 and is configured to accommodate the illumination unit 100, the conversion unit 200, and the heating unit 300. The case 500 can be implemented using a well-known streetlamp case, one side of which is formed to be transparent, in order to illuminate a roadway and a path while the CCFLs 110 of the illumination unit 100 are turned on.

[64] The above-described present invention can be implemented in various forms, without departing from the technical spirit or principal features of the invention. Therefore, the above embodiments are only examples in all aspects, and should not be interpreted as restrictive. Industrial Applicability

[65] The present invention provides a streetlamp, in which the operating environment of an SMPS can be controlled, thus enabling the streetlamp to be smoothly operated in the summer and winter seasons and in outdoor places, and which can control the lighting of respective illumination lamps to efficiently maintain illumination status, thus reducing power consumption. Accordingly, the streetlamp can be used in various illumination fields, such as for outdoor places, for example, streets or lanes, and for tunnels.

Claims

[1] A streetlamp, comprising: an illumination unit including a plurality of Cold Cathode Fluorescent Lamps

(CCFLs); a conversion unit including a Switching-Mode Power Supply (SMPS) to convert a voltage level of commercial power into a voltage level used for the illumination unit; a heating unit installed adjacent to the SMPS; a control unit for controlling lighting of the illumination unit and ON-OFF operation of the heating unit; and a case for accommodating the illumination unit, the conversion unit, and the heating unit.

[2] The streetlamp according to claim 1, wherein the heating unit comprises a temperature sensor for sensing a temperature of the SMPS, and is operated such that, when heating is performed at a temperature higher than an operating temperature of the SMPS, the control unit performs a control operation to turn off the heating unit.

[3] The streetlamp according to claim 1, wherein the control unit comprises illuminance control means for controlling ON-OFF operation of all of the CCFLs of the illumination unit depending on an illuminance sensed by an illuminance sensor.

[4] The streetlamp according to claim 1, wherein the control unit comprises timer control means for performing a control operation such that the CCFLs of the illumination unit switch from a fully ON-state to a partially ON-state on a basis of a set time point.

[5] The streetlamp according to claim 1, wherein the control unit comprises human body sensing control means for performing a control operation such that the CCFLs of the illumination unit switch from a partially ON-state to a fully ON- state for a predetermined period of time when an approach of a pedestrian is sensed.