Differences in the degree of polarization can be utilized at manufacturing sites to detect container content. For example, in picking work for LSI chips they can be used to confirm whether chips have been placed to fit in the correct position. In pharmaceutical manufacturing, differences in the degree of polarization between tablets and aluminum sheets can be applied to confirm tablet container content.

With conventional types of polarization sensors, the polarizer is attached on top of the on-chip lens layer (Fig.2, left), however with Sony’s polarization sensor, the polarizer is formed on chip under the on-chip lens layer (Fig.2, right). A shorter distance between the polarizer and the photodiode improves the extinction ratio*3 and the incident angle dependence.Since the polarizer is formed during the semiconductor process, form and formulation of polarizer, uniformity, mass productivity and durability are excellent compared to conventional polarization sensors. Furthermore, Sony’s Polarization sensor is covered with an anti-reflection layer which helps to reduce reflectance and avoids poor flare and ghost characteristics.

Polaroid 600camera

In observations conducted by fixed-point cameras for the enforcement of traffic regulations, light can be reflected by vehicle windshields depending on the time period and angle, making it impossible to identify individuals in the vehicle. By setting polarization image sensors as appropriate, this reflected light can be reduced or removed, allowing the number of individuals in the vehicle to be detected.

These examples show dents and dust on a homogenous glass plane.（Left/Right） We can easily find scratches and stains (fingerprint and dust) due to differences in the degree of polarization. （Right）

Middle English, from Latin illuminatus, past participle of illuminare, from in- + luminare to light up, from lumin-, lumen light — more at luminary

Polarized cameralens

Sony’s polarization sensor can capture a four directional polarization image in one shot by the four directional polarizer (Fig.1). It can calculate the direction and degree of polarization (DoP) based on the intensity of each directional polarization. Together with subsequent signal processing, it can capture the polarization information*1 in real time*2.

This introduces a behind-the-scenes story of the development and future possibilities of the anticipated polarization image sensor for versatile applications in various industries.

Light has physical elements : brightness (amplitude), color (wavelength) and polarization (vibration direction). Lights from the Sun or fluorescent lamps vibrate in various directions and is called unpolarized light.

Polarized cameraamazon

“Illuminate.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/illuminate. Accessed 18 Dec. 2024.

The light is reflected by the surface of the object in polarized and unpolarized lights. The DoP of the reflected light depends on the surface condition (material, color, roughness etc.) and the angle of reflection.

Polarizationcameraprice

Polarsens is a CMOS Image Sensor pixel technology that has several different angle polarizer formed on chip during the semiconductor process allowing highly accurate alignment with pixel. This allows it to solve issues faced in various industrial areas.

Sony’s polarization sensor has wire-grid polarizers. Parallel light against polarizer passes through it, while perpendicular light is cut off at the polarizer.

InstantCamera

With the information of direction of polarization, we can identify both distortions and the direction of distortion of the plane. (Right)

Polarization image sensors can be used for distortion inspections in various manufacturing industries. They can accurately detect the presence of distortion without becoming confused by color or reflections, and can even detect the direction of distortions.

PolaroidcameraVintage

*3) Extinction ratio is a specification to measure polarization. The extinction ratio of polarization image sensor is the ratio between the sensitivity of transmission axis light and the sensitivity of extinction axis light (the sensitivity of transmission axis light / the sensitivity of extinction axis light). The higher the number, the better the specification and performance.

Polaroid film

To detect fine scratches on plane surfaces which are completely uniform like glass at manufacturing sites, it is necessary to distinguish between scratches and stains. Since scratches differ from stains in that they have a specific orientation, polarization image sensors can be applied to focus on those properties.Polarization image sensors can reliably identify differences in the degree of polarization between uneven areas, accurately perceiving scratches with a specific direction and detecting them while distinguishing them from stains which have random irregularities.

The direction of polarization image (upper right) shows the angle of the polarization direction in color using HSV color mapping (left below).In this example, the upper side of the cube is highlighted in light blue meaning that the angle of the polarization direction is 90 degree.

Using a polarization image sensor can remove the reflected light regardless of the vehicle type, improving the accuracy of face recognition.

Polaroid photo

Polarization has two physical information, which are the degree of polarization and the direction of polarization. This information can be used for various applications such as surface scratch detection, particle inspection, distortion and shape recognition which has traditional been difficult to detect.

A polarizing filter can be used to remove the reflected light. However, reflected light may remain depending on the vehicle type (window angle).

In the Degree of Polarization image (right) the white is high polarization and black is low polarization.As example, the stitch is easily visible due to the difference in the degree of polarization of the thread and leather.

Thanks to the difference in the degree of polarization between the tablet and the aluminum package, it is easy to identify whether the tablets are filled in or not. (Right)