Pico Projector DMD Parking Circuit for Vehicle Door Reliability

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Solution Overview

Problem

The frequent power cycling of pico projectors in vehicles due to door opening and closing causes damage to digital micromirror devices (DMDs), reducing the reliability of the pico projectors installed on vehicle doors.

Innovation Solution

A pico projector system with a processing circuit that receives a shutdown warning signal, transmits a parking signal to the DMD, and notifies the power supply to cut off power after a predetermined time interval, allowing sufficient time for the DMD to complete a parking operation and avoid damage, using capacitors to extend the voltage supply duration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If power is cut off immediately when the door is closed, then power consumption is reduced, but the DMD may be damaged due to sudden power loss and reduced reliability

Engineering Contradiction:
Improvepower consumptionVSAvoidpico projector reliability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The system performs preliminary action by issuing a shutdown warning signal before actually cutting off power to the DMD. The processing circuit receives this warning signal, transmits a parking signal to the DMD to complete the parking operation, and only then notifies the power supply to cut off power after a predetermined time interval. This preliminary warning allows the DMD to safely park its micromirrors before power loss, preventing damage while still enabling power savings.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If power is supplied continuously to the DMD, then the DMD can complete parking operations reliably, but power is wasted when the projector is not in use

Engineering Contradiction:
ImproveDMD operation reliabilityVSAvoidpower waste
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system implements periodic action by using a predetermined time interval between the shutdown warning signal and the actual power cutoff. This time interval is sufficient for the DMD to complete its parking operation, creating a rhythmic pattern of operation-waiting-shutdown that ensures reliable parking while minimizing power consumption. The power is not cut off immediately but after a controlled periodic delay.

Inventive Principle:
Principle #19Periodic action

3Reliability

If the shutdown warning signal is issued early, then the DMD has sufficient time to park micromirrors, but the light source and transducer consume power unnecessarily for an extended period

Engineering Contradiction:
Improvemicromirror parking completionVSAvoidlight source and transducer power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system applies segmentation by controlling different components with different timing. The processing circuit notifies the power supply to cut off power to different components at different times - the DMD receives extended power for the predetermined time interval to complete parking, while the light source and transducer can be cut off earlier. This segmented power management ensures reliable micromirror parking while minimizing overall power consumption.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3745202B1Pico projector and control method therefor; vehicle comprising the same
Publication Date: 2022.04.06 CORETRONIC CORPORATION
  • EP3745202B1 patent drawingFigure 1~2
  • EP3745202B1 patent drawingFigure 3~4
  • EP3745202B1 patent drawingFigure 5

AI summary

A pico projector, a control method of the pico projector and a vehicle comprising the pico projector installed in a door are provided. The pico projector (100) includes a light source (110), a DMD (120), a projection lens (130), a power supply unit (140), and a processing circuit (150). The processing circuit receives a shutdown warning signal, transmits a parking signal to the DMD to perform a parking operation on the DMD, and notifies the power supply unit of cutting off a first power provided to the DMD after a predetermined time interval from transmitting the parking signal.