Light emission device and illumination device

Abstract

The present invention is provided with: a light source unit (3) that emits excitation light (101); a light deflection unit (140) that deflects the excitation light (101); a wavelength conversion unit(160) that is irradiated with the excitation light (101) deflected by the light deflection unit (140), converts the excitation light (101) into wavelength-converted light of a different wavelength, and emits said wavelength-converted light; and a light-condensing unit (10) that condenses the excitation light (101) on the wavelength conversion unit (160). The light-condensing unit (10) comprises: afirst optical system (11) that is disposed between the light source unit (3) and the light deflection unit (140); and a second optical system (12) that is disposed between the light deflection unit (140) and the wavelength conversion unit (160). If an axis in a direction in which a beam parameter product of the excitation light (101) is at a minimum is referred to as the Ax axis, and an axis in adirection orthogonal to the Ax axis is referred to as the Ay axis, in a cross section orthogonal to the travel direction of the excitation light (101), the focal distance in the Ay axis direction inthe second optical system (12) is shorter than the focal distance in the Ax axis direction.

Description

technical field [0001] The present disclosure relates to a light emitting device that irradiates a wavelength conversion unit with excitation light emitted from a light source unit to cause the wavelength conversion unit to generate light different from the excitation light, and an illumination device including the light emitting device. Background technique [0002] Illumination devices using laser light sources such as semiconductor light emitting elements (semiconductor laser elements) include spot lighting, vehicle headlights, projectors, endoscope lighting, and the like. In these illuminating devices, a wavelength converter composed of a phosphor represented by yttrium aluminum garnet (YAG) is irradiated with laser light having a wavelength near 400 nm or near 450 nm, and the fluorescence generated by the excitation of the phosphor, Alternatively, emitted light composed of fluorescence and scattered components of excitation light is used as illumination light. In such ...

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Problems solved by technology

Therefore, in the case where the phosphor is formed on a flat surface and the scanning area of ​​the excitation light is set to a certain size, the rate of change of the optical path length increases as the scanning area of ​​the excitation light approaches, so that it cannot sufficiently The excitation light is concentrated, and the diameter of the bright spot on the phosphor is enlarged

Furthermore, in the case of an optical system configuration in which the incident angle of the phosphor is large, there is a problem that the bright spot is greatly inclined as the scanning position of the excitation light approaches both ends.

In addition, in order to scan a certain distance, it is necessary to increase the deflection angle of the light deflection unit. According to the method of driving the movable mirror with a magnetic circuit, the heat resistance of the coil due to the increase in current and the strength of the spring holding the mirror Durability can be an issue

In addition, the increase of the deflection angle of the light deflection unit leads to an increase in the range (effective range) in which the excitation light irradiates the optical element on the scanning optical path, which leads to problems such as an increase in the size of the device and an increase in the cost of the optical components.

[0013] On the other hand, as in Patent Document 2, when the condensing optical system is arranged between the light deflection unit and the phosphor, the light beam is refracted toward the focus direction of the condensing optical system due to the refraction effect of the lens on the deflected light beam. Therefore, Sensitivity (i.e., amount of displacement) on the phosphor to deflection angle is reduced

Therefore, it is necessary to design the deflection angle by the light deflection part to be large, which also causes the above-mentioned problems in this case.

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