Lamp Memory for Uniform Light Output

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Solution Overview

Problem

Existing illumination devices struggle to reliably reset the cumulative lighting time of lamps, especially when replaced, leading to inconsistent light output due to difficulties in detecting the end of life for LED lamps and requiring complex control methods for fluorescent lamps.

Innovation Solution

An illumination device with a built-in illuminance correction unit that includes a timer, memory, and temperature measurement unit, allowing for accurate resetting of cumulative lighting time and dimming ratio adjustment based on illuminance correction characteristics, ensuring uniform light output regardless of lamp type or age.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complicated control method is used to determine lamp replacement, then the reliability of resetting cumulative lighting time is improved, but the device complexity and cost increase

Engineering Contradiction:
Improvereliability of resetting cumulative lighting timeVSAvoidcontrol method complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the lamp system into two independent parts: the lamp itself contains a memory device storing cumulative lighting time, while the illumination device contains a microcomputer that reads this data. This segmentation allows the lamp to carry its own operational history, eliminating the need for complex detection systems in the illumination device and enabling reliable reset when the lamp is replaced.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses a memory device within the lamp to store and copy the cumulative lighting time data. This copied information can be read by the microcomputer in the illumination device, providing a simple and reliable method to determine whether the lamp has been replaced without requiring complex control methods.

Inventive Principle:
Principle #26Copying

2Measurement precision

If the memory device is provided in the illumination device, then the cumulative lighting time can be tracked, but the device complexity and cost increase

Engineering Contradiction:
Improvecumulative lighting time tracking accuracyVSAvoidillumination device complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the memory storage function from the illumination device and places it within the lamp itself. The lamp's memory device stores the cumulative lighting time, while the illumination device's microcomputer only needs to read this data. This segmentation reduces the complexity of the illumination device while maintaining accurate tracking capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lamp performs self-service by containing its own memory device that automatically records and stores cumulative lighting time. This eliminates the need for the illumination device to actively track and store this information, reducing its complexity while ensuring accurate measurement is maintained.

Inventive Principle:
Principle #25Self-service

3Illumination intensity

If dimming control is applied to compensate for aging, then the light output uniformity is improved, but the device complexity increases

Engineering Contradiction:
Improvelight output uniformityVSAvoidcontrol system complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent merges the dimming control function with the existing microcomputer in the illumination device. The microcomputer reads cumulative lighting time from the lamp's memory, determines the appropriate dimming ratio based on aging characteristics, and controls the lamp output accordingly. This integration achieves light output uniformity without adding separate complex control systems.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2375860B1Illumination device, lamp, lighting circuit, and illumination apparatus
Publication Date: 2019.05.08 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2375860B1 patent drawingFigure 1
  • EP2375860B1 patent drawingFigure 2
  • EP2375860B1 patent drawingFigure 3~5

AI summary

An illumination device includes a replaceable lamp including at least one light emitting element; a lighting device for lighting the light emitting element by supplying a power to the lamp; and an illuminance correction unit for performing a dimming control on the lamp. The illuminance correction unit includes a timer for counting a cumulative lighting time of the light emitting element and a memory for storing the cumulative lighting time counted by the timer. The illuminance correction unit determines a dimming ratio of the light emitting element based on the cumulative lighting time stored in the memory and an illuminance correction characteristic, in which the relationship between the cumulative lighting time and the dimming ratio of the light emitting element is determined to uniformly maintain a light output from the light emitting element even when the cumulative lighting time increases. The memory is provided in the lamp.