Vehicular Lamp Light Guide Uniformity
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Solution Overview
Problem
Conventional vehicular lamps with plate-shaped light guide portions do not project light uniformly due to uneven light distribution from rod-shaped light guide portions, resulting in non-uniform illumination.
Innovation Solution
The use of thin-walled portions at the end rim portions of the plate-shaped light guide portion, combined with dot-shaped lens cuts and random arrangements, ensures uniform light projection by diffusing light from rod-shaped guide portions and correcting optical paths to eliminate dark areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light enters the plate-shaped light guide portion from rod-shaped light guide portions, then light projection is achieved, but the light distribution becomes uneven with larger amount near first end portions and smaller amount near second end portions
Solution Approach 1:
The patent applies local quality by making the plate-shaped light guide portion thinner at its end portions compared to the central region. This variable thickness design creates different optical paths and light extraction characteristics at different locations, specifically compensating for the uneven light distribution by allowing more light to exit from regions where it accumulates and directing more light toward regions where it is deficient.
Solution Approach 2:
The patent changes the geometric parameter of the plate-shaped light guide portion by varying its thickness across different regions. The thickness parameter is specifically reduced at the end portions relative to the central region, which alters the optical properties and light propagation characteristics to achieve more uniform light projection along the longitudinal axis.
2Ease of manufacture
If the plate-shaped light guide portion has uniform thickness, then manufacturing is simplified, but light projection uniformity deteriorates
Solution Approach 1:
The patent applies local quality by making the plate-shaped light guide portion thinner at its end portions compared to the central region. This variable thickness design creates different optical paths and light extraction characteristics at different locations, specifically compensating for the uneven light distribution by allowing more light to exit from regions where it accumulates and directing more light toward regions where it is deficient.
Solution Approach 2:
The patent changes the geometric parameter of the plate-shaped light guide portion by varying its thickness across different regions. The thickness parameter is specifically reduced at the end portions relative to the central region, which alters the optical properties and light propagation characteristics to achieve more uniform light projection along the longitudinal axis.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration allows for uniform light projection and improved visibility, enhancing the aesthetic appeal and functionality of the vehicular lamp by maintaining a high light-to-dark ratio and suppressing moiré effects.
Implementation Method 1
The first end rim portion and the second end rim portion of the plate-shaped light guide portion (34) each include a thin-walled portion (NP1, NP2) whose thickness is smaller than that of the plate-shaped light guide portion (34) other than the first end rim portion (EG1) and the second end rim portion (EG2), respectively
Implementation Method 2
US 2017/234501 A1 was used as a basis for the preamble of claim 1 and discloses a vehicle lamp which includes a light source and a light guide body configured to guide light from the light source therein and emit the light toward a front side of the lamp. The light guide body includes a first rod-shaped light guide portion configured to guide light incident from an incident end surface, a second rod-shaped light guide portion configured to guide the incident light, and a plate-shaped light guide portion formed in an area between the first rod-shaped light guide portion and the second rod-shaped light guide portion. The plate-shaped light guide portion has an end side surface configured to totally reflect at least a portion of light, which travels in the plate-shaped light guide portion, toward the first rod-shaped light guide portion and/or the second rod-shaped light guide portion.
Data Source
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AI summary
Provided is a vehicular lamp in which the plate-shaped light guide portion (34, 34A) can project light uniformly or can be visually recognized/observed as if it emits light uniformly. A vehicular lamp unit (10) includes a light guide body (30, 30A), and a light source (21a, 21b, 21A) configured to emit light guided in the light guide body (30, 30A). The light guide body (30, 30A) includes a first rod-shaped light guide portion (33a, 33Aa) configured to guide light from the light source (21a, 21A) from a proximal end (BE33a) thereof to a distal end (FE33a) thereof, a second rod-shaped light guide portion (33b, 33Ab) configured to guide light from the light source (21b, 21Ab) from a proximal end (BE33b) thereof to a distal end (FE33b) thereof, and a plate-shaped light guide portion (34, 34A) disposed between the first rod-shaped light guide portion (33a, 33Aa) and the second rod-shaped light guide portion (33b, 33Ab). The first rod-shaped light guide portion (33a, 33Aa) and the second rod-shaped light guide portion (33b, 33Ab) are juxtaposed with each other with a space therebetween. The plate-shaped light guide portion (34, 34A) includes a front surface (FS34, FS34A) disposed on a front side of the vehicular lamp unit and a rear surface (RS34, RS34A) disposed on a back side opposite to the front side, and also includes a first end rim portion (EG1, EG1A) configured to be connected to an outer peripheral surface of the first rod-shaped light guide portion (33a, 33Aa), and a second end rim portion (EG2, EG2A) configured to be connected to an outer peripheral surface of the second rod-shaped light guide portion (33b, 33Ab). The rear surface (RS34, RS34A) of the plate-shaped light guide portion (34, 34A) includes a plurality of structures (LC2) configured to diffuse the light from the light source (21a, 21b, 21A) entering the plate-shaped light guide portion (34, 34A) from the respective first and second rod-shaped light guide portions (33a, 33Aa, 33b, 33Ab) and cause the light to exit from the front surface (FS34, FS34A) of the plate-shaped light guide portion (34, 34A). The first end rim portion (EG1, EG1A) and the second end rim portion (EG2, EG2A) of the plate-shaped light guide portion (34, 34A) each include a thin-walled portion (NP1, NP1A, NP2, NP2A) having a thickness thinner than that of the plate-shaped light guide portion (34, 34A) except for the first and second end rim portions (EG1, EG1A, EG2, EG2A).