Digital pointer position detector

• US 4,631,539 A
• Filed: 01/19/1983
• Issued: 12/23/1986
• Est. Priority Date: 01/19/1983
• Status: Expired due to Fees

• Current Assignee: Adalet / Scott Fetzer Company
• Original Assignee: The Scott Fetzer Company (Berkshire Hathaway Incorporated)
• Inventors: Sanders, Gary G., Corwon, Michael E.
• Primary Examiner(s): Caldwell, Sr., John W.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/459,262
• Time in Patent Office: 1,434 Days
• Field of Search: 340/347 P, 340/870.02, 340/870.03, 340/870.29, 340/870.31, 340/870.32, 250/231 SE, 250/354.1, 455/615, 455/618
• US Class Current: 340/870.29
• CPC Class Codes: G01D 13/26 adapted to perform a further operation, e.g. making electrical contact
• CPC Class Codes: H03M 1/28 with non-weighted coding

Abstract

A mechanical dial indicating gauge or meter that, without mechanical loading, optoelectronically detects and encodes the pointer position as a digital signal by use of a technique of distributed point position latching. Counter means drives a circuit which cylically sequentially lights LED'"'"'s along a scale and the count is latched that corresponds to current counter position when a detector on the scale pointer is activated during the sequential lighting. This latched count provides the digital signal of pointer position. This digital signal may then by transmitted to remote indicators, controllers, computers, and/or may be compared to preset values yielding set point outputs. An electrical lead for the detector includes a spiral loosely surrounding the pointer stem.

Claims

1. An indicating gauge or meter of the scalar dial type with an indicator pointer whose position may be signalled with acceptable resolution and with negligible torsional mechanical loading of the pointer or associated pointer linkage, said indicating gauge comprising:

said pointer, an arcuate or linear indicator scale along which said pointer moves, an array of LED'"'"'s arranged along said scale and each having its own unique address, said array of LED'"'"'s being of a high linear density corresponding to acceptable resolution for indicator scale readings, a photodetector mounted as a unitary part of said indicator pointer to sweep as a part of the pointer itself back and forth in both directions over said high density array of LED'"'"'s according to the movements of said pointer, means for cyclically sequentially lighting the LED'"'"'s for single point transmission independently of said pointer'"'"'s position and correspondingly counting through the addresses of LED'"'"'s being lighted, on a one-to-one basis of single point activation to instantaneously-current count, whereby each said LED in said high-linear density single point transmission array is lighted only for the instant that its unique address is the instantaneously-current count, buffer means responsive to activation of said photodetector for latching the count corresponding to the pointer'"'"'s then-obtained position as the sequential lighting of the LED'"'"'s cycles to or past the photodetector whereby the then-obtained position of said pointer defines the value of said latched count and the defined value of the latched count identifies pointer position with a degree of resolution acceptable for indicator gauge readings.

2. A device as in claim 1, set point means for setting a discrete set point corresponding to any one of the addresses of the LED'"'"'s, and comparator means for signalling whether the latched count corresponding to the pointer'"'"'s then-obtained position compares to the set point value in at least one of the following ways:

less than, less than or equal to, equal to, greater than or equal to, greater than, or unequal to the set point value.

3. A device as in claim 1, in which said LED'"'"'s arranged along said scale emit photodetector-stimulating light at a given dispersion angle and said pointer-mounted photodetector moves through the intersections of the rays of the dispersion angles of each adjacent pair of LED'"'"'s as said photodetector sweeps over said array of LED'"'"'s.

4. A device as in claim 2, output delay means including RC time constant means for delaying the signal from said comparator means to thereby dampen pointer oscillations around a set point.

5. A device as in claim 4, said output delay means being adjustable for varying the degree of dampening.

6. A device as in claim 1, said pointer being mounted on a stem and turning on the axis of the stem to cause the sweeping of the photodetector over the corresponding array of LED'"'"'s, and a pair of electrical leads joining the photodetector to the remainder of the circuitry of the device.

7. An indicating gauge or meter with an indicator pointer whose position may be signalled with negligible torsional mechanical loading of the pointer or associated pointer linkage, said indicating gauge comprising:

said pointer, an arcuate or linear indicator scale along which said pointer moves, an array of LED'"'"'s arranged along said scale and each having its own unique address, a photodetector mounted on said indicator pointer to sweep back and forth over said array of LED'"'"'s according to the movements of said pointer, means for cyclically sequentially lighting the LED'"'"'s independently of said pointer'"'"'s position and correspondingly counting through the addresses of LED'"'"'s being lighted whereby each LED is lighted only for the instant that its unique address is the instantaneously-current count, buffer means responsive to activation of said photodetector for latching the count corresponding to the pointer'"'"'s then-obtained position as the sequential lighting of the LED'"'"'s cycles past the photodetector whereby the then-obtained position of said pointer defines the value of said latched count said pointer being mounted on a stem and turning on the axis of the stem to cause the sweeping of the photodetector over the corresponding array of LED'"'"'s, and a pair of electrical leads joining the photodetector to the remainder of the circuitry of the device, at least one of said leads comprising at least in part a wire formed as a spiral extending along the stem from said pointer toward the base of the stem, the spiral loosely surrounding the stem.

8. An indicating gauge or meter with an indicator pointer whose position may be signalled with negligible torsional mechanical loading of the pointer or associated pointer linkage, said indicating gauge comprising:

said pointer, an arcuate or linear indicator scale along which said pointer moves, an array of LED'"'"'s arranged along said scale and each having its own unique address, a photodetector mounted on said indicator pointer to sweep over said array of LED'"'"'s, means for cyclically sequentially lighting the LED'"'"'s and correspondingly counting through the addresses of LED'"'"'s being lighted whereby each LED is lighted only for the instant that its unique address is the instantaneously-current count, buffer means responsive to activation of said photodetector for latching the count corresponding to the pointer'"'"'s then-obtained position as the sequential lighting of the LED'"'"'s cycles past the photodetector whereby the then-obtained position of said pointer defines the value of said latched count, said pointer being mounted on a stem and turning on the axis of the stem to cause the sweeping of the photodetector over the corresponding array of LED'"'"'s, and a pair of electrical leads joining the photodetector to the remainder of the circuitry of the device, said pointer being made of electrically conductive material, at least one of said leads comprising at least in part said pointer itself.

9. An indicating gauge or meter with an indicator pointer whose position may be signalled with negligible torsional mechanical loading of the pointer or associated pointer linkage, said indicating gauge comprising:

said pointer, an arcuate or linear indicator scale along which said pointer moves, an array of LED'"'"'s arranged along said scale and each having its own unique address, a photodetector mounted on said indicator pointer to sweep over said array of LED'"'"'s, means for cyclically sequentially lighting the LED'"'"'s and correspondingly counting through the addresses of LED'"'"'s being lighted whereby each LED is lighted only for the instant that its unique address is the instantaneously-current count, buffer means responsive to activation of said photodetector for latching the count corresponding to the pointer'"'"'s then-obtained position as the sequential lighting of the LED'"'"'s cycles past the photodetector whereby the then-obtained position of said pointer defines the value of said latched count, said pointer being mounted on a stem and turning on the axis of the stem to cause the sweeping of the photodetector over the corresponding array of LED'"'"'s, and a pair of electrical leads joining the photodetector to the remainder of the circuitry of the device, said pointer and stem being made of electrically conductive material, one of said leads comprising in part a wire formed as a spiral loosely surrounding and extending along the stem from said pointer toward the base of the stem, the other of said leads comprising in part the stem itself, and one of said leads comprising in part the pointer itself.

10. An indicating gauge or meter with an indicator pointer whose position is signalled with negligible torsional mechanical loading of the pointer or associated pointer linkage, said indicating gauge comprising:

said pointer, an arcuate or linear indicator scale along which said pointer moves, photoelectronic sensing and signalling means for detecting and signalling the position of the pointer, said means including an electronic circuit with an array of fixed circuit elements arranged along said scale and a moving circuit element carried on said pointer to sweep over said array, said pointer being mounted on a stem and turning on the axis of the stem to cause said sweeping, a pair of electrical leads joining the moving circuit element to the remainder of the electronic circuit, at least one of said leads comprising in part a wire formed as a sprial loosely surrounding and extending along the stem from the pointer toward the base of the stem.

11. An indicating gauge or meter with an indicator pointer whose position is signalled with negligible torsional mechanical loading of the pointer or associated pointer linkage, said indicating gauge comprising:

said pointer, an arcuate or linear indicator scale along which said pointer moves, photoelectronic sensing and signalling means for detecting and signalling the position of the pointer, said means including an electronic circuit with an array of fixed circuit elements arranged along said scale and a moving circuit element carried on said pointer to sweep over said array, said pointer being mounted on a stem and turning on the axis of the stem to cause said sweeping, a pair of electrical leads joining the moving circuit element to the remainder of the electronic circuit, at least one of said leads comrprising in part a wire formed as a sprial loosely surrounding and extending along the stem from the pointer toward the base of the stem, the other of said leads comprising in part the stem itself, and one of said leads comprising in part the pointer itself.