Road sign device and spontaneously emitted light sign system used for the device

• US 6,726,398 B2
• Filed: 10/30/2001
• Issued: 04/27/2004
• Est. Priority Date: 02/17/2000
• Status: Expired due to Fees

• Current Assignee: Sekisui Jushi Kabushiki Kaisha
• Original Assignee: Sekisui Jushi Kabushiki Kaisha
• Inventors: Kaneko, Yasuo, Hamakawa, Yasuhiko, Inagaki, Katsuhito
• Primary Examiner(s): Will, Thomas B.
• Assistant Examiner(s): Addie, Raymond W
• Application Number:
  US09/959,552
• Publication Number:
  US 20020159834A1
• Time in Patent Office: 910 Days
• Field of Search: 404/13, 404/14, 404/15, 404/16, 404/12, 362/153.1, 359/531, 359/532, 359/545
• US Class Current: 404/13
• CPC Class Codes: E01F 9/559 illuminated
• CPC Class Codes: F21S 8/022 intended to be recessed in a floor or like ground surface, e.g. pavement or false floor
• CPC Class Codes: F21S 9/037 the solar unit and the lighting unit being located within or on the same housing
• CPC Class Codes: F21V 23/0442 activated by means of a sensor, e.g. motion or photodetectors
• CPC Class Codes: F21V 31/005 Sealing arrangements therefor
• CPC Class Codes: F21W 2111/00 Use or application of lighting devices or systems for signalling, marking or indicating, not provided for in codes F21W2102/00 – F21W2107/00
• CPC Class Codes: F21W 2111/02 for roads, paths or the like
• CPC Class Codes: F21W 2111/04 for waterways
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/20 Electroluminescent [EL] light sources
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection
• CPC Class Codes: Y02B 20/72 in street lighting

Abstract

A road marking device comprises: a tubular, bottomed casing which has an open top end; a cover mounted over an opening in the casing and having a window; a self-luminous marking system composed of a condenser housed in the casing, an illuminant which emits light by receiving a power supplied from the condenser, and a circuit for driving the illuminant; and a transparent element which transmits and outwardly radiates the light emitted from the illuminant. The transparent element is fixed between the cover and the casing which cooperatively hold a periphery of the transparent element, with a part of the transparent element protruding outwardly from the window in the cover. In a self-luminous marking system, an LED is utilized without application of voltage so as to detect the quantity of light in the road environment and to generate an electromotive force in response to an incident light. Based on the electromotive force generated by this LED, the drive of a display LED is controlled.

Claims

1. A road marking device, which comprises:

a tubular, bottomed casing which has an open top end;

a cover mounted over said opening in the casing and having a window;

a self-luminous marking system composed of an energy storage device housed in the casing, an illuminant which emits light by receiving a power supplied from the energy storage device, and a circuit for driving the illuminant; and

a transparent element which transmits and outwardly radiates the light emitted from the illuminant,

wherein the transparent element is fixed between the cover and the casing which cooperatively hold a periphery of the transparent element, and wherein a part of the transparent element protrudes outwardly from the window in the cover;

wherein the casing is provided with an edge which outwardly and horizontally projects from a top end periphery of the casing, and a vertical wall which vertically extends from a certain portion of the edge as formed along a whole circumference thereof, and the cover has a bent wall which can be closely attached to an external circumference of the vertical wall, and

wherein the casing is capped with the cover, with the external circumference of the vertical wall being closely attached to the bent wall, and the transparent element is fixed in a clamped manner by the edge, an internal circumference of the vertical wall and the cover which cooperatively hold a periphery of the transparent element.

2. A road marking device as claimed in claim 1, wherein the transparent element comprises an external circumferential wall, and wherein a packing material is inserted between the external circumferential wall of the transparent element and the vertical wall, such that the transparent element presses on the vertical wall with interposition of the packing material.

3. A road marking device as claimed in claim 2, wherein the packing material is inserted in a recess formed in the external circumferential wall of the transparent element, such that the transparent element presses on the vertical wall with interposition of the packing material.

4. A road marking device as claimed in claim 1, wherein a screw groove is formed in each of an external circumferential surface of the vertical wall and an internal circumferential surface of the bent wall,

wherein the cover is fixed in close contact with the casing when the screw grooves are engaged with each other.

5. A road marking device as claimed in claim 1, wherein a recess is formed in at least either of an external circumferential surface of the vertical wall or an internal circumferential surface of the bent wall,

wherein the cover is fixed on the casing by a packing material inserted in the recess.

6. A road marking device as claimed in claim 1, wherein a ridge is formed on each of an external circumferential surface of the vertical wall and an internal circumferential surface of the bent wall, with each ridge being engageable with the other,

wherein the cover is fixed on the casing when the ridges are engaged together.

7. A road marking device as in any of claims 1 to 3, wherein each of the vertical wall and the bent wall has a bolt hole, with the bolt holes communicating with one another when an external circumferential surface of the vertical wall is closely attached to an internal circumferential surface of the bent wall,

wherein the cover is fixed in close contact with the casing by a bolt screwed into these bolt holes.

8. A road marking device as in any of claims 1 to 3, wherein each of the edge and the bent wall has a bolt hole, with the bolt holes communicating with one another when a top surface of the edge is closely attached to a bottom end surface of the bent wall,

wherein the cover is fixed in close contact with the casing by a bolt screwed into these bolt holes.

9. A road marking device as claimed in claim 1, wherein the cover is equipped with a flange which outwardly and horizontally projects from a bottom end of the bent wall, and a spring steel is provided for tightly clamping the flange and the edge,

wherein the cover is fixed in close contact with the casing by the spring steel.

10. A self-luminous marking system which comprises:

a first LED which emits light when a quantity of light in a road environment is less than a predetermined level;

a battery for supplying a power to the first LED;

a drive circuit for controlling a drive of the first LED;

a second LED utilized without application of voltage so as to generate an electromotive force in response to an incident light;

a light quantity discrimination circuit which determines, based on the electromotive force generated by the second LED, whether the quantity of light in the road environment is less than the predetermined level; and

a switch circuit which controls an operation of the drive circuit, based on a result determined by the light quantity discrimination circuit.

12. A self-luminous marking system as claimed in claim 10 or 11, wherein the light quantity discrimination circuit starts to operate, when the second LED continuously generates an electromotive force for a given time in response to the incident light.

11. A self-luminous marking system which comprises:

a first LED which emits light when a quantity of light in a road environment is less than a predetermined level;

a solar battery and a condenser element for supplying a power to the first LED;

a drive circuit for controlling a drive of the first LED;

a second LED utilized without application of voltage so as to generate an electromotive force in response to an incident light;

a light quantity discrimination circuit which determines, based on the electromotive force generated by the second LED, whether the quantity of light in the road environment is less than the predetermined level; and

a switch circuit which controls an operation of the drive circuit, based on a result determined by the light quantity discrimination circuit.

13. A road marking device which comprises:

a tubular, bottomed casing which has an open top end;

a cover mounted over an opening in the casing and having a window;

a self-luminous marking system composed of a power source housed in the casing, an illuminant which emits light by receiving a power supplied from the power source, and a circuit for driving the illuminant; and

a transparent element which transmits and outwardly radiates the light emitted from the illuminant,

wherein the transparent element is fixed between the cover and the casing which cooperatively hold a periphery of the transparent element, with a part of the transparent element protruding outwardly from the window in the cover,

wherein the self-luminous marking system comprises;

a battery as the power source;

a first LED which emits light by receiving a power supplied from the battery, when a quantity of light in a road environment is less than a predetermined level;

a drive circuit for controlling a drive of the first LED;

a second LED utilized without application of voltage so as to generate an electromotive force in response to an incident light;

a light quantity discrimination circuit which determines, based on the electromotive force generated by the second LED, whether the quantity of light in the road environment is less than the predetermined level; and

a switch circuit which controls an operation of the drive circuit, based on a result determined by the light quantity discrimination circuit.

14. A road marking device as claimed in claim 13, wherein the power source comprises a solar battery and a condenser element.

15. A road marking device as claimed in claim 13 or 14, wherein the casing is provided with an edge which outwardly and horizontally projects from a top end periphery of the casing, and a vertical wall which vertically extends from a certain portion of the edge as formed along a whole circumference thereof, and the cover has a bent wall which can be closely attached to an external circumference of the vertical wall, and

wherein the casing is capped with the cover, with the external circumference of the vertical wall being closely attached to the bent wall, and the transparent element is fixed in a clamped manner by the edge, an internal circumference of the vertical wall and the cover which cooperatively hold a periphery of the transparent element.