What is Light guide?

Light guide is a lighting tool to pass through light from one side to another side efficiently using internal reflection of transparent resin. Recently the adoption to home appliances and general industry equipments has been increasing.
By using light guide, it enables to uniformly illuminate areas apart from light source, which brightness of the area is originally uneven.
Light guide can be roughtly divided into two types - Injection moulding light guide and Optical fiber light guide.

Differences between injection moulding light guide and optical fiber light guide

Features on injection moulding light guide

This type of light guide is made by injection moulding PC(polycarbonate) or PMMA(acrylic resin) and so on.
While molding tool per products is needed, it enables to make various designed optical products - long light guide or rounded/square shaped lens and so on according to your needs.
Also you can choose the lighting method like Prism, Brast and Dot. The direction of light distribution and the balance of brightness can change to suit customer's request.

Features on fiber light guide

Generally, fiber light guide is known for its manufacturing way through extrusion molding.
Therefore, the fiber's cross-section shape or its size is limited to a specific type however it doesn't cost so much itinially since there is no need to make tools per products like as injection moulding light guide.
From its flexible material's characterstics, you can bend it freely and the complex optical design is not needed. However it is not possible to illuminate a specific direction only or change the brightness depending on part.
Also you need to consider a structure to fix fiber light guide.

Features on Oshino's Light guide

Our light guide is manufactured through injection moulding method and its shape can be designed freely and you can choose materials(PC, PMMA etc.) according to your request.
There are various illumination methods like Prism, Brast and Dots and you can also combine these method.
With above environment and techniques, Oshino proposes best product to customer's requests.

Our integrated system from product design to mass production

Oshino does production process from proposal/design for light guide as per customer's request, to design/production for tool, injection moulding and inspection.
It enables to provide products quickly and with high quality.

Production factory specialized in transparent resin moulding

Our factory is located in Yamanshi prefecture and manufactures various optical products in clean environment specialized in transparent resin.

Yamanashi Factory

Light guide Production factory in Yamanashi, Japan

Introduction of global advanced design and technology

Oshino has strong global network - engineering team for optical design in Germany and production factory for optical products in Estonia.
They design and manufacture products for interior illumination for European automotive makers.

Light guide for seatbelt buckle

Development and production achievement

We have developed and achieved light guide production as below.

  • - Long light guide (Over 700mm)
  • - Light guide for Power window switch
  • - Circle and square lens used for AUX and USB port
  • - Map lens for car interior
  • - Light guide for display lamp of disaster preventing equipments
    and so on...

Key points to choose Light guide


Both fiber light guide and injection moulding light guide would
As for fiber light guide, you can bend freely when you use due to its soft material, however it is necessary to consider the way to fix.


While injection moulding light guide needs initial cost for making mold tool, fiber light guide doen't need it.
However, compared with each of products, injection moulding light guide can be cheaper than fiber light guide in mass production.

Lighting pattern

Light of fiber light guide is emitted in 360 degree along its fiber.
On the other hand, injection moulding light guide can control its light direction optionally.
It has various illumination methods like Prism, Brast and Dots according to your needs and you can also combine these method.

Prism method : This processing is not suitable for direct illumination since it's easy to see the pattern. But it is appropriate for indirect illumination as it lights brightly.
Blast method : The light amount is smaller than that of Prism method however its pattern is not visible. Besides, light uniformity can be calibrated so it is suitable for direct illumination.
Fiber method : The pattern is not visible and it can be used for direct illumination.
Dot method : This processing is brighter than that of Blast method and its pattern is less visible than that of Prism method.

Blasting Process

Prism Process Image
Lightguide Mold