Expectations for plastic lenses are becoming more demanding
The expectations for plastic lenses are becoming even more demanding in order to meet the more lightweight and compact, and higher resolution requirements. To match market trends, there are high-performance resins being researched, developed and used. And even within our own company, we are currently testing new materials and making steady strides toward mass production performance.
Advantages of plastic lenses
・Low cost (approximately 1/10th the cost of glass)
・Durable against impact
・Easy to mold and process aspheric surfaces
Advances are being made in coating technology and its surface hardness is also catching up to glass lenses. Depending on the field and application, the use of plastic lenses is gaining momentum as a replacement. Various types of performance resins are being released into the market to match application and performance requirements.
＜High-performance polycarbonate resins＞
Conventional PC resins are used in CDs & DVDs and lenses for eyewear because it is transparent and inexpensive. Recently, there have been further advances in the development of high-grade, high-performance PC resins
（MITSUBISHI GAS CHEMICAL COMPANY, INC.）
These resins have an extremely low birefringence and a high refractive index. With a high fluidity, they are not only fitting for thin-wall molding, but they have superior durability. As a result, they can also be used in various lens field applications such as cellular phones with cameras, digital cameras, cameras for vehicles with strict usage conditions (such as rear-view cameras) and surveillance cameras
|Glass transition temperature||145||121|
|Water absorption coefficient||0.35||0.37|
○◎：There are a mass production results.
※：There are a prototype manufacturing results.
While having the same transparency as a standard PC resins, there is also less optical distortion in the molding products. In addition, it has heat resistant properties and can be molded under the same conditions as standard PC resins.
Due to its durability against performance loss even under long usage conditions, it is also used not only with camera lenses but optical sensors, industrial lenses and optical films.
This is a special polycarbonate resin with a low Abbe number for general optics.
|Glass transition temperature||156||145|
|Water absorption coefficient||0.2|
＜High-performance polyester resins＞
（Osaka Gas Chemicals Co., Ltd.）
The attributes for this resin’s properties include a refractive index of more than 1.6, a low birefringence and a high fluidity. As a result, it is used with optical photography lenses and sensor covers, etc. In addition, the need for all types of aberration correction lenses such as chromatic aberration lenses in particular is expanding.
|Glass transition temperature||121||143|
|Water absorption coefficient||0.2||0.2|
＜High-performance circular resins＞
APEL（Mitsui Chemicals, Inc.）
This high-performance resin with its low birefringence has been able to acquire a significant share in the optical disk market where optical pickup lenses are used. Other applications include fθ lenses for laser printers, lenses for image sensors and also the health care field due to its chemical resistance.
TOPAS（Polyplastics Co.,Ltd.）This resin possesses optical characteristics that are comparable to PMMA (acrylic) and a heat resistance that exceeds PC. Dimension accuracy is easy to carry out because it forms and molds smoothly.
|Glass transition temperature||90||125||140|
|Water absorption coefficient||4||0.01||0.01|
|Glass transition temperature||139||156|
|Water absorption coefficient||0.01||0.01|
We are engaged in projects focusing on product sizes between Ø2 – 40, with an accuracy level of ±0.1 µm
Test production for plastic lenses in 1 month
Designs in 2 – 5 days
Wire processing in 3 – 5 days
Cutting & electric discharge processing in 3 – 7 days
Heat treatment in 1 day
Secondary surface treatment in 3 days
Main processing in 1 day
Partial finishing in 1 day
Finishing & assembly adjustments in 1 day
Molding in a half day
Correction processing in 1.5 days
Light guide & LED display windows in 12 – 16 days (No surface precision requirement)
Coaxially-symmetrical, spherical & aspherical surface lenses, light guides, AF windows with guaranteed surface precision, emitter windows, simple toroidal shaped surfaces in 13 – 17 days
Lens types with free-form surfaces in 25 – 30 days
*We deliver only products that have passed the required precision level.