Surface Emission Laser Pulse Control for Thermal Crosstalk

The patent applies periodic action by sequentially driving multiple surface emission lasers instead of simultaneous operation. The drive circuit outputs drive pulses to lasers in a time-division manner, where each laser is activated for a specific time period followed by a pause. This periodic operation allows the substrate to dissipate heat between activation cycles, preventing thermal crosstalk while maintaining overall productivity through coordinated sequential emission across the laser array.

The patent implements periodic action by controlling the drive circuit to activate lasers in sequential time periods rather than simultaneously. Each laser receives drive pulses during its designated time window, followed by a pause period that allows thermal dissipation. This periodic operation pattern enables the substrate temperature to return toward baseline between activation cycles, preventing cumulative heat buildup and thermal crosstalk while maintaining high overall productivity through efficient time-division multiplexing of the laser array.

The patent applies preliminary action by measuring the substrate temperature before driving each laser and using this temperature information to determine the appropriate drive current. The drive circuit adjusts the drive current based on the pre-measured temperature, applying higher current only when necessary to compensate for existing thermal conditions. This preliminary temperature assessment prevents excessive heat generation by avoiding unnecessary current increases, thereby maintaining light emission intensity while minimizing additional heat production.