At the Mobile World Congress 2017, Bosch introduced a combo of a micro-scanner and projector, capable of turning any surface into a virtual user interface. Bosch is the world’s oldest and biggest manufacturer of micro-electro-mechanical systems (MEMS), and in its combo projector, it is using infrared for scanning and laser for projecting.
Currently, engineers are using MEMS devices for a variety of gadgets, especially where a human-machine interface (HMI) is necessary. These include in-car heads-up displays, infotainment, medical devices, robotics, industrial equipment, and on the factory floor. With the new microscanner BML050, Bosch Sensortech has extended its portfolio to include optical microsystems. This move also expands Bosch’s market from being only a component supplier to becoming a system supplier as well.
To sense where the user has placed his finger on the projected interactive display, the new Bosch BML050 uses a combination on two MEMS scanning mirrors. One of the mirrors tracks the X-direction, while the other scans the Y-direction. Sensing the finger also makes use of an infrared laser and an RGB laser.
The integrated module for infrared, red, green, and blue (IR-RGB) is only 6 mm high, and is capable of HD resolution. The two MEMS scanning mirrors are capable of both projecting images as well as collecting the reflected light, thereby determining accurately where the user’s finger is touching the projected image. According to Bosch, this technique is adaptable to 3-D scanning as well, where they can apply time-of-flight calculations using the reflected light from an object.
A major advantage over Digital Light Processors (DLPs), the Bosch laser-based MEMS scanner is always in focus, even when the projection surface is uneven. According to Stefan Finkbeiner, the chief executive officer of Bosch Sensortech, DLPs require thousands of mirrors that need focusing, and the entire outfit is expensive.
At present, the reference design of the Bosch BML050, although containing all the technicalities for use in almost any application, is much larger than the expected OEM circuit board. Finkbeiner informs that despite this, customers are already integrating the BML050 into their products, and they will be in the market by Christmas this year.
The BML050 has a two-mirror system, with one hinged in the X-direction and the other in the Y-direction. The mirror system projects from the module, which measures only 6 x 24 mm, and uses 30-lumen lasers. This arrangement allows Bosch to alter the size when using low-power lasers, or when using high-power lasers for instance, for industrial sized images. The reference design for the BML050 contains all required drivers and processors. This includes ASICs for driving the mirrors, processing the video, managing all colors, managing the system and laser power with two PMICs.
According to Finkbeiner, the two-MEMS mirror architecture is very simple to integrate. Therefore, for the future, Bosch is planning to use a sealed module design after further miniaturization. The design will then be suitable for use in tiny gadgets such as for IoTs and smartphones. Very soon, you may find virtual human-machine interfaces on everything from toys to industry equipment on the factory floor, robotics, medical devices, and infotainment such as in in-car heads-up displays.
