# US 8,465,171 B2 · Headlamp and vehicle infrared night vision apparatus employing the headlamp as light source

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,465,171 B2
- Document ID: US8465171B2
- Status: Granted
- Kind: B2
- Application number: 12/402,309
- Filed: 2009-03-11
- Published: 2009-09-17
- Granted: 2013-06-18
- Earliest claimed: 2008-03-13
- Assignees: Sharp Kabushiki Kaisha
- Applicants: Katsuhiko Kishimoto; Junichi Kinomoto
- Inventors: Katsuhiko Kishimoto; Junichi Kinomoto
- Web page: https://patentgrep.com/patent/US8465171B2

## CPC

- B60Q 1/04: the devices being headlights
- B60Q: ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL

## Abstract

A headlamp is provided, which has lower power consumption, a longer service life and a more compact size and yet is capable of easily projecting visible light and near infrared light in desired light distribution patterns. The headlamp includes a wavelength converting member and an excitation light source. The wavelength converting member includes a visible light fluorescent material which is excited by excitation light emitted from the excitation light source to emit visible light, and a near infrared fluorescent material which is excited by the excitation light emitted from the excitation light source to emit near infrared light. The visible light and the excitation light are mixed together to generate white light. The excitation light source is a semiconductor solid-state element.

## Claims

### Claim 1

A headlamp comprising:
a wavelength converting member; and
a single excitation light source emitting excitation light in a blue wavelength range or a blue-violet wavelength range;
wherein the wavelength converting member includes a visible light fluorescent material which is excited by the excitation light emitted from the single excitation light source to emit visible light, and, in addition to the visible light fluorescent material, a near infrared fluorescent material which is excited by the excitation light emitted from the single excitation light source to emit invisible near infrared light having a peak wavelength falling substantially within a range of 850 nm to 1000 nm;
the visible light and the excitation light emitted from the single excitation light source are mixed together to generate white light; and
the excitation light source is a semiconductor solid-state element.

### Claim 2 (depends on 1)

The headlamp according to claim 1, wherein
the visible light fluorescent material has a light emission peak in a yellow wavelength range.

### Claim 3 (depends on 1)

The headlamp according to claim 1, wherein
the visible light fluorescent material includes a first fluorescent material having a light emission peak in a green wavelength range and a second fluorescent material having a light emission peak in a red wavelength range.

### Claim 4 (depends on 1)

The headlamp according to claim 1, wherein
the visible light fluorescent material has a light emission spectrum including a from a blue wavelength to a red wavelength.

### Claim 5 (depends on 1)

The headlamp according to claim 1, further comprising a light blocking member which defines a light distribution pattern,
wherein the light blocking member partly blocks the visible light and transmits the invisible near infrared light so that the headlamp functions as a vehicle headlamp for projecting a low beam.

### Claim 6 (depends on 1)

The headlamp according to claim 1,
wherein the excitation light source is a light emitting diode.

### Claim 7 (depends on 1)

The headlamp according to claim 1,
wherein the excitation light source is a semiconductor laser.

### Claim 8 (depends on 1)

The headlamp according to claim 1,
wherein the semiconductor nano-particles comprise InP particles having a particle diameter of 5 to 100 nm.

### Claim 9 (depends on 1)

The headlamp according to claim 1,
wherein the semiconductor nano-particles comprise GaAs particles having a particle diameter of 10 to 100 nm.

### Claim 10 (depends on 1)

The headlamp according to claim 1, wherein
the peak wavelength of the emitted invisible near infrared light falls substantially within a range of 850 nm to 950 nm.

### Claim 11 (depends on 10)

The headlamp according to claim 10, wherein
the peak wavelength of the emitted invisible near infrared light is about 900 nm.

### Claim 12 (depends on 1)

The headlamp according to claim 1, wherein
the near infrared fluorescent material is semiconductor nano-particles.

### Claim 13

A vehicle infrared night vision apparatus comprising:
a headlamp; and
a near infrared camera;
wherein the headlamp includes:
a wavelength converting member; and
a single excitation light source emitting excitation light in a blue wavelength range or a blue-violet wavelength range;
wherein the wavelength converting member includes a visible light fluorescent material which is excited by the excitation light emitted from the single excitation light source to emit visible light, and, in addition to the visible light fluorescent material, a near infrared fluorescent material which is excited by the excitation light emitted from the single excitation light source to emit invisible near infrared light having a peak wavelength falling substantially within a range of 850 nm to 1000 nm;
the visible light and the excitation light emitted from the single excitation light source are mixed together to generate white light;
the excitation light source is a semiconductor solid-state element; and
wherein the near infrared camera includes:
a light receiving element having a silicon PIN diode and receiving the invisible near infrared light emitted from the near infrared fluorescent material.

### Claim 14 (depends on 13)

The vehicle infrared night vision apparatus according to claim 13, wherein
the headlamp is used as a vehicle headlamp for projecting a low beam.

### Claim 15 (depends on 13)

The vehicle infrared night vision apparatus according to claim 13, wherein
the peak wavelength of the emitted invisible infrared light falls substantially within a range of 850 nm to 950 nm.

### Claim 16 (depends on 15)

The vehicle infrared night vision apparatus according to claim 15, wherein
the peak wavelength of the emitted invisible infrared light is about 900 nm.

### Claim 17 (depends on 13)

The vehicle infrared night vision apparatus according to claim 13, wherein
the near infrared fluorescent material is semiconductor nano-particles.
