Optical image focusing device with audible indication

Claim 2

In a device for aiding the focusing of an optically formed image at a predetermined plane, the combination comprising photoconductive cell means for developing a first electrical signal value dependent upon the degree of focus of an optical image incident thereon, means for generating a second electrical signal varying with the value of said first electrical signal, and, means responsive to said second electrical signal generating means for producing an audible tone of a frequency related to said second electrical signal, whereby said audible tone varies in pitch according to the degree of focus of said optical image.

Claim 3

The focusing device of claim 1, wherein said photoconductive cell means comprises body means for placing upon a surface co-planar with said predetermined plane, and, reflective means contained within said body means for directing light images incident upon said surface to said photoconductive cell.

Claim 4

The focusing device of claim 2, further comprising means for adjusting the relative position within said body means of said photoconductive cell and said reflective means.

Claim 5

The focusing device of claim 3, wherein said body means includes a threaded aperture positioned along an axis parallel to said surface when said body means is placed thereon, and, further comprising threaded means connected to said photoconductive cell for adjustably moving said cell in said threaded aperture.

Claim 6

The focusing device of claim 1, wherein said responsive means comprises oscillator means for producing an alternating voltage in the audio range, electrical amplifier means for increasing the power level of said alternating voltage, and, speaker means connected to the output of said amplifier means for making said alternating voltage audible.

Claim 7

The focusing device of claim 5, wherein said oscillator means comprises a voltage Controlled variable frequency multivibrator.

Claim 8

The focusing device of claim 1, wherein said means for generating a second electrical signal comprises amplifier means for producing a d.c. voltage level as a function of said first electrical signal value, and, filter means for removing from said d.c. voltage level any unwanted audio frequency voltage components.

Claim 9

The focusing device of claim 1, wherein said means for developing a first electrical signal comprises body means for placing upon a surface co-planar with said predetermined plane for containing said photoconductive cell means, and, reflective means contained within said body means for directing light images incident upon said surface to said photoconductive cell, and, said responsive means comprises oscillator means for producing an alternating voltage in the audio range, electrical amplifier means for increasing the power level of said alternating voltage, and, speaker means connected to the output of said amplifier means for making said alternating voltage audible.

Claim 10

The focusing device of claim 8, wherein said oscillator means comprises a voltage controlled variable frequency multivibrator.

Claim 11

In a device for aiding the focusing of an optically formed image, the combination comprising, photoconductive cell means for developing an electrical conductance value dependent upon the degree of focus of an optical image incident thereon, amplifier means for generating a d.c. voltage level dependent upon the value of said conductance, oscillator means connected to receive the d.c. voltage level for producing an alternating voltage in the audio range of a frequency proportional to said level, and, speaker means connected to the output of said oscillator means for making said alternating voltage audible, whereby said audible alternating voltage varies in pitch according to said electrical conductance value and said degree of focus.

Claim 12

In a device for aiding the focusing of an optically formed image, the combination comprising, photoconductive cell means for developing an electrical conductance value dependent upon the degree of focus of an optical image incident thereon, amplifier means for generating a d.c. voltage level dependent upon the value of said conductance, oscillator means connected to receive the d.c. voltage level for producing an alternating voltage in the audio range of a frequency proportional to said level, and, speaker means connected to the output of said oscillator means for making said alternating voltage audible, whereby said audible alternating voltage varies in pitch according to said electrical conductance value and said degree of focus.

Claim 13

In a device for aiding the focusing of an optically formed image at a predetermined plane, the combination comprising, body means for placing upon a surface co-planar with said predetermined plane, said body means including a threaded aperture positioned along an axis parallel to said surface when said body means is placed thereon, photoconductive cell means for developing an electrical conductance value as a function of the degree of focus of an optical image incident thereon, threaded means connected to said photoconductive cell means for adjustably moving said cell in said threaded aperture, reflective means connected to said body means for directing light images incident upon said surface to said photoconductive cell, amplifier means for producing a d.c. voltage level dependent upon said value of electrical conductance, filter means for removing from said d.c. voltage level any unwanted audio voltage components, variable frequency multivibrator means connected to generate an alternating voltage in the audio range dependent upon said d.c. voltage level, electrical amplifier means for increasing the power level of said alternating voltage, and, speaker means connected to the output of said amplifier means for making said alternating voltage audible.

Claim 14

In a device for aiding the focusing of an optically formed image at a predetermined plane, the combination comprising, body means for placing upon a surface co-planar with said predetermined plane, said body means including a threaded aperture positioned along an axis parallel to said surface when said body means is placed thereon, photoconductive cell means for developing an electrical conductance value as a function of the degree of focus of an optical image incident thereon, threaded means connected to said photoconductive cell means for adjustably moving said cell in said threaded aperture, reflective means connected to said body means for directing light images incident upon said surface to said photoconductive cell, amplifier means for producing a d.c. voltage level dependent upon said value of electrical conductance, filter means for removing from said d.c. voltage level any unwanted audio voltage components, variable frequency multivibrator means connected to generate an alternating voltage in the audio range dependent upon said d.c. voltage level, electrical amplifier means for increasing the power level of said alternating voltage, and, speaker means connected to the output of said amplifier means for making said alternating voltage audible.