Mr. Frank Prass Profile

Frank Prass

SPIE Involvement:

Author

Publications (1)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 17 June 2024 Presentation + Paper

Performance of UV-molded versus injection molded maskless microlens arrays for multi-aperture projection

R. Kundu, D. Michaelis, D. Stefanidi, P. Schreiber, A. Schöneberg, R. Leitel, F. Prass, B. Schaller

Proceedings Volume 13021, 130210J (2024) https://doi.org/10.1117/12.3016164

KEYWORDS: Stray light, Lens arrays, Projection systems, Modeling, Injection molding, Monte Carlo methods, Microlens array, Light emitting diodes, Grayscale lithography, Illumination engineering, Freeform optics, Diffusers

Read Abstract +

Maskless microlens arrays (MLA) for multi-aperture projection offer high transmission due to absence of buried absorbing mask structures for shaping the pattern. Arbitrary shaped lenslets arranged in a high fill-factor array form the entrance MLA, the apertures of each entrance lenslet are projected towards the far-field by regularly shaped lenslets of the exit array. Resulting tandem MLA is arranged in a fly’s eye homogenizer (FEH) configuration. Such MLAs are mastered by grayscale photolithography and replicated as UV-molded polymer-on-glass (POG) elements. Furthermore, such maskless projectors can be realized using alternative replication technologies, primarily - injection molding (IM), which offers low cost for large area replication. MLA designed for POG replication can be adapted for IM replication by adjustment of certain parameters, e.g., thickness due to material substitution. Since the shape of the lenslets remain same for both processes, the same MLA masters can be used to generate the tooling molds necessary for IM replication. However, unlike POG replication, IM technology lacks active alignment of the entrance and exit arrays which makes IM replicated MLAs more vulnerable to crosstalk and stray light. Hence, a trade-off between ease of manufacturing (low costs) and projected image quality (sharpness, contrast, stray light) should be considered when dealing with IM replication. In this work we describe an exemplary IM replicated maskless MLA, based on masters of a previously realized POG replicated MLA for an automotive projected blinker. We discuss the design adaptation to IM and present profilometric and photometric characterization of the IM replicated MLA. We also compare the characterization results of the IM MLA samples with that of ‘gold-standard’ POG replicated MLA and discuss performance, quality of projection and limitations of IM technology.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years