High-speed and high-precision optical sensor features VCSEL technology

ROHM has developed the RPR-0730, an analogue compact optical sensor, capable of high-precision detection of fast-moving objects. This sensor can be widely utilised in consumer and industrial equipment applications, including printers and conveyor systems.

As industrial and office equipment becomes increasingly sophisticated and automated, there is a growing demand for improved sensing technology accuracy. In applications such as label printers, material or product transport systems, and copiers, the necessity for technology that can identify objects more accurately is vital. Moreover, increased speed driven by productivity improvements makes the introduction of high-speed, high-precision optical sensors crucial.

The new device is a compact reflective optical sensor (photo reflector). It employs an infrared VCSEL, which provides higher directionality than LEDs, allowing detection of finer objects. Furthermore, using a phototransistor with an analogue output as the receiver, the sensor achieves a response time of 10µs. This dual combination allows high-speed, accurate identification of fine lines as narrow as 0.1mm, previously difficult to detect with conventional LED light sources. As an addition to the existing digital output sensor RPR-0720 series, the new series expands the capability for applications that demand faster sensing, such as print detection in copiers and label printers, and rotational detection in motors and gears.

The package is ultra-compact at 2mm × 1mm × 0.55mm and employs a visible light filtering resin to suppress interference from ambient light or sunlight. This enables stable detection even in environments with varying lighting conditions, such as factories or outdoor settings. The sensor can also be readily integrated into equipment requiring installation in small, confined spaces, such as inside conveyors or precision instruments, making it suitable for a wider range of applications.

Application examples include print detection, paper feed/jam detection in label printers, copiers, shredders, etc.; object detection of packages/specimens, workpiece position detection in conveyance systems, automatic inspection equipment, etc.; and motor/gear rotational detection in industrial robots, etc.