# US 9,867,737 B2 · Auto-darkening filter of welding shield

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,867,737 B2
- Document ID: US9867737B2
- Status: Granted
- Kind: B2
- Application number: 14/725,559
- Filed: 2015-05-29
- Published: 2016-12-01
- Granted: 2018-01-16
- Earliest claimed: 2015-05-29
- Assignees: John David Fergason; Anthony Wang Lee
- Applicants: John David Fergason; Anthony Wang Lee
- Inventors: John David Fergason
- Web page: https://patentgrep.com/patent/US9867737B2

## CPC

- A61F 9/065: {use of particular optical filters (A61F9/022, A61F9/062 take precedence)}
- G01J 1/18: using comparison with a reference electric value
- G01J 1/26: adapted for automatic variation of the measured or reference value (regulation of light intensity G05D25/00)
- G01J 2001/0276: {Protection}
- G02F 1/13318: {Circuits comprising a photodetector}
- A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C)
- G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N)
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS

## Abstract

An auto-darkening filter of a welding shield has a brightness-sensing unit, an optical shutter and a processor. The brightness-sensing unit generates a first signal or a second signal. In a high-sensitivity mode, the processor controls the optical shutter to operate in a dark state or a bright state depending on intensity of the first signal being higher or lower than a threshold value. In a low-sensitivity mode, the processor controls the optical shutter to operate in the bright state when intensity of the second signal is lower than the threshold value, and automatically change to the high-sensitivity mode from the low-sensitivity mode when intensity of the second signal is higher than the threshold value.

## Claims

### Claim 1

An auto-darkening filter of a welding shield, the auto-darkening filter comprising:
a brightness-sensing unit generating a first signal or a second signal, the first signal obtained from a base signal scaled by M time(s), the second signal obtained from the base signal scaled by N time(s), and N<M; wherein the brightness-sensing unit comprises
an optical sensor generating the base signal directly proportional to environmental brightness sensed by the optical sensor;
a signal amplifier connected to the optical sensor; and
a gain controller connected to the signal amplifier;
an optical shutter operating in a bright state or a dark state; and
a processor connected to the signal amplifier, the gain controller, and the optical shutter, wherein
the processor sends a control command to the gain controller, and the gain controller activates the signal amplifier to generate the first signal or the second signal according to the control command;
when the processor operates in a higher-scaled-signal mode, the processor controls the brightness-sensing unit to generate the first signal, controls the optical shutter to operate in the dark state during a period that the first signal is higher than a threshold value, and controls the optical shutter to operate in the bright state during a period that the first signal is lower than the threshold value; and
the processor changes to a lower-scaled-signal mode from the higher-scaled-signal mode when a change-mode command is received; in the lower-scaled-signal mode, the processor controls the brightness-sensing unit to generate the second signal, controls the optical shutter to operate in the bright state during a period that the second signal is lower than the threshold value, and changes to the higher-scaled-signal mode from the lower-scaled-signal mode when the second signal is higher than the threshold value and remains in the higher-scaled-signal mode after the first signal is no longer higher than the threshold value until the change-mode command is received.

### Claim 2 (depends on 1)

The auto-darkening filter as claimed in claim 1, wherein the optical shutter is a liquid crystal shutter.

### Claim 3 (depends on 2)

The auto-darkening filter as claimed in claim 2, wherein the optical shutter has better lightproof capability operating in the dark state than operating in the bright state.

### Claim 4 (depends on 1)

The auto-darkening filter as claimed in claim 1, wherein the optical shutter has better lightproof capability operating in the dark state than operating in the bright state.