Image scanner drive system

Claim 5

A method as defined by claim 2 wherein the step of modulating a light beam includes reflecting said light beam from said mechanical element, thereby to direct the reflected light beam along a path that is dependent upon the position of the element, and further wherein the step of detecting the degree of light beam modulation includes detection of the path of the reflected light beam.

Claim 6

The method as defined by claim 2 which additionally comprises the step of electronically differentiating the position electrical signal and adding said differential to said error signal for changing the position of the mechanical element, whereby the differential signal provides an electronic damping.

Claim 7

Apparatus for controlling motion of an object, comprising, a light modulator attached to said object, means for directing a light beam toward said light modulator and thence as a modulated light beam, a light detector positioned in the path of said modulated light beam for generation of an electrical signal that is proportional to the degree of light beam modulation, whereby said electrical signal is proportional to the position of the object, means for comparing the object position electrical signal with a reference electrical signal, thereby producing an error signal, and means including an electrical motor for driving the object in response to said error signal.

Claim 8

Apparatus for controlling motion of an object, comprising, a light modulator attached to said object, means for directing a light beam toward said light modulator and thence as a modulated light beam, a light detector positioned in the path of said modulated light beam for generation of an electrical signal that is proportional to the degree of light beam modulation, whereby said electrical signal is proportional to the position of the object, means for comparing the object position electrical signal with a reference electrical signal, thereby producing an error signal, and means including an electrical motor for driving the object in response to said error signal.

Claim 9

Apparatus according to claim 5 which additionally comprises an electronic differentiating circuit which adds a differential of said object position signal to said error signal for driving said electrical motor.

Claim 10

Apparatus according to claim 5 wherein said light modulator is a mirror and said light detector generates an electrical signal output proportional to the position at which the reflected light beam strikes the detector.

Claim 11

Apparatus according to claim 5 wherein said object is pinned in a manner to rotate back and forth about a single axis over an arc length less than 90*.

Claim 12

An optical scanning assembly, comprising, a mirror that is rotatable aboUt an axis for a defined arc distance less than 90*, an electrical motor operably connected to said mirror for angularly rotating the mirror back and forth throughout its said defined arc distance, means for directing electromagnetic energy from an object onto said mirror for controllable reflection therefrom, a reflective surface on the backside of said mirror element, means for directing a light beam onto said backside reflective surface from a position fixed in space with respect to the axis of rotation of said mirror element, thereby to generate a reflected light beam having a position that is proportional to the angular position of the mirror element, and detecting means in the path of said reflected light beam for generating an electrical signal that is substantially linearly proportional to the position on the detector that is struck by said reflected light beam.

Claim 13

An optical scanning assembly, comprising, a mirror that is rotatable aboUt an axis for a defined arc distance less than 90*, an electrical motor operably connected to said mirror for angularly rotating the mirror back and forth throughout its said defined arc distance, means for directing electromagnetic energy from an object onto said mirror for controllable reflection therefrom, a reflective surface on the backside of said mirror element, means for directing a light beam onto said backside reflective surface from a position fixed in space with respect to the axis of rotation of said mirror element, thereby to generate a reflected light beam having a position that is proportional to the angular position of the mirror element, and detecting means in the path of said reflected light beam for generating an electrical signal that is substantially linearly proportional to the position on the detector that is struck by said reflected light beam.

Claim 14

An optical scanning assembly according to claim 9 wherein the reflective surface on the backside of the mirror element is substantially the same size as the light beam that strikes it, thereby to minimize various reflections from the backside of the mirror element onto the detector.

Claim 15

An optical scanning assembly according to claim 9 wherein said means for directing a light beam onto the reflective surface includes an optical element for causing the reflected light beam to be focused into a substantial point on the detector.

Claim 16

An optical scanning assembly according to claim 11 wherein the detector includes a photosensitive area that is limited to a substantial line across which said substantial point of light travels in response to rotation of said mirror element about its axis.

Claim 17

An optical scanning instrument, comprising: a point radiation detector which generates a time varying electrical signal that is proportional to the intensity of radiation incident thereon, a rotating mirror assembly for scanning the horizontal aspects of an object field image across said point detector, an angularly rotatable mirror positioned to scan the vertical aspects of the object radiation field image across said detector, a torque motor for angularly rotating said vertical scanning mirror, an electronic circuit for synthesizing a voltage function that is proportional to the desired motion of the vertical scanning mirror, a reflective surface on the backside of said scanning mirror, means for directing a light beam against the reflective surface on the backside of the vertical mirror, thereby to generate a reflected light beam that travels in a path dependent upon the angular position of the vertical scanning mirror, a photosensitive detector positioned in the path of the reflected light beam to generate an electrical signal that is proportional to the position on the detector at which the reflected light beam strikes, means for comparing the detector output signal with the synthesized voltage function and for developing an electrical signal proportional to the differences therebetween, an electronic differentiating circuit receiving the output signal of the detector, means for adding the differential signal to said difference signal, thereby producing a composite error signal that includes electronic damping, and means responsive to said error signal for driving said torque motor in a direction to minimize said error signal.

Claim 18

An optical scanning instrument, comprising: a point radiation detector which generates a time varying electrical signal that is proportional to the intensity of radiation incident thereon, a rotating mirror assembly for scanning the horizontal aspects of an object field image across said point detector, an angularly rotatable mirror positioned to scan the vertical aspects of the object radiation field image across said detector, a torque motor for angularly rotating said vertical scanning mirror, an electronic circuit for synthesizing a voltage function that is proportional to the desired motion of the vertical scanning mirror, a reflective surface on the backside of said scanning mirror, means for directing a light beam against the reflective surface on the backside of the vertical mirror, thereby to generate a reflected light beam that travels in a path dependent upon the angular position of the vertical scanning mirror, a photosensitive detector positioned in the path of the reflected light beam to generate an electrical signal that is proportional to the position on the detector at which the reflected light beam strikes, means for comparing the detector output signal with the synthesized voltage function and for developing an electrical signal proportional to the differences therebetween, an electronic differentiating circuit receiving the output signal of the detector, means for adding the differential signal to said difference signal, thereby producing a composite error signal that includes electronic damping, and means responsive to said error signal for driving said torque motor in a direction to minimize said error signal.

Claim 19

An optical scanning assembly according to claim 9 which additionally comprises: means for generating a reference electric signal proportional to the desired angular rotation of said mirror as a function of time, means receiving said reference electric signal and said electrical signal from said detecting means for continuously generating an error signal proportional to a difference between said reference and detector signals, and means receiving said error signal for driving said mirror electric motor in a direction to minimize said error signal.

Claim 20

An opTical scanning assembly, comprising: an optical element rotatable about an axis through a defined arc distance for directing an object image onto an image detector and for scanning that image in at least one direction over the image detector, an electrical motor operably connected to said optical element for angularly rotating said element back and forth throughout its said defined arc distance, means directing a light beam toward said optical element for generating a reflected light beam having a position that is proportional to the angular position of the optical element, and position detecting means in the path of said reflected light beam for generating an electrical signal that is proportional to the position on the position detector struck by said reflected light beam.

Claim 21

An opTical scanning assembly, comprising: an optical element rotatable about an axis through a defined arc distance for directing an object image onto an image detector and for scanning that image in at least one direction over the image detector, an electrical motor operably connected to said optical element for angularly rotating said element back and forth throughout its said defined arc distance, means directing a light beam toward said optical element for generating a reflected light beam having a position that is proportional to the angular position of the optical element, and position detecting means in the path of said reflected light beam for generating an electrical signal that is proportional to the position on the position detector struck by said reflected light beam.

Claim 22

An optical scanning assembly according to claim 15 which additionaly comprises: means for generating a reference electric signal proportional to the desired angular rotation of said mirror as a function of time and in synchronism with a video vertical scanning oscillator output, means receiving said reference electric signal and said electrical signal from said detecting means for continuously generating an error signal proportional to a difference between said reference and detector signals, and means receiving said error signal for driving said mirror electric motor in a direction to minimize said error signal.

Claim 23

An optical scanning instrument, comprising: a point radiation detector which generates a time varying electrical signal that is proportional to the intensity of radiation incident thereon, a rotating mirror assembly for scanning the horizontal aspects of an object field image across said point detector, an angularly rotatable mirror positioned to scan the vertical aspects of the object radiation field image across said detector, an electric motor for angularly rotating said vertical scanning mirror, a vertical scanning electronic oscillator generating a generally sawtooth waveform, and means receiving said vertical generally sawtooth waveform for applying it to said electric motor, whereby said angularly rotatable mirror is rocked in synchronism with said vertical scanning electronic oscillator output.

Claim 24

An optical scanning instrument, comprising: a point radiation detector which generates a time varying electrical signal that is proportional to the intensity of radiation incident thereon, a rotating mirror assembly for scanning the horizontal aspects of an object field image across said point detector, an angularly rotatable mirror positioned to scan the vertical aspects of the object radiation field image across said detector, an electric motor for angularly rotating said vertical scanning mirror, a vertical scanning electronic oscillator generating a generally sawtooth waveform, and means receiving said vertical generally sawtooth waveform for applying it to said electric motor, whereby said angularly rotatable mirror is rocked in synchronism with said vertical scanning electronic oscillator output.