Reflection densitometer

Claim 2

An instrument for providing an indication of the intensity of the light reflected from a test region, comprising: a supporting structure; a target carried by the supporting structure, said target having a preselected location which is adapted to be placed over said test region, said preselected location of said target being capable of passing light; a head including means for providing a beam of light and means for transmitting reflected light; means for mounting said head on said supporting structure for movement between a retracted position in which said head leaves said preselected location uncovered whereby said preselected location of said target can be placed over said test region and an operative position in which said head overlies said preselected location so that it can direct said beam of light therethrough and said light transmitting means communicates with said preselected location of said target to receive and transmit light reflected from said test region; and means responsive to a characteristic of the light reflected into said light transmitting means for providing an indication of the intensity of the light reflected from the test region.

Claim 3

An instrument as defined in claim 1 wherein said means for mounting said head pivotally mounts said head on said supporting structure, said instrument including linkage means for pivoting said head between said positions thereof.

Claim 4

An instrument as defined in claim 2 wherein said linkage includes an arm pivotally mounted on said supporting structure and drivingly interrelated with said head to pivot the latter and a member pivotally mounted on said supporting structure and drivingly interrelated with said arm to pivot the latter, said instrument including means for biasing said head toward at least one of said positions thereof.

Claim 5

An instrument as defined in claim 1 wherein said target includes means defining a recess with said preselected location being in said recess, said head including a projection receivable in said recess in said operative position.

Claim 6

An instrument as defined in claim 1 wherein said head includes a housing, a light in said housing for providing said beam of light, and light sensitive means in said housing responsive to the intensity of the reflected light for providing a signal, said means for providing an indication including means outside of said housing responsive to said signal for providing said indication.

Claim 7

An instrument as defined in claim 1 wherein said beam of light and the reflected light transmitted by said light transmitting means lie substantially in the same plane, the reflected light transmitted by said light transmitting means forming a reading angle with a reference line, said reading angle being in the range of from 28* to about 60*, said reference line being is said plane and oriented so as to be generally perpendicular to said surface when said plane is perpendicular to said surface.

Claim 8

The instrument as defined in claim 1 wherein said target is rigidly affixed to said supporting structure and immovable relative thereto.

Claim 9

The instrument as defined in claim 6 wherein said head includes a housing and said means for providing a beam of light includes a lamp in said housing, a filter wheel circumscribing said lamp and mounted for rotation within said housing, a plurality of filters carried by said wheel and selectively interposable into the path of the reflected light.

Claim 10

An instrument as defined in claim 7 wherein said head is pivotable between said positions thereof, said head including a projection and said target having a recess, said projection being at least partially receivable in said recess in said operative position, said preselected location being within said recess.

Claim 13

A method as defined in claim 10 wherein said reading angle is approximately 50*.

Claim 14

A method as defined in claim 10 wherein said reading angle is approximately 30*.

Claim 15

A method as defined in claim 10 wherein said lamp angle is approximately + 10*.

Claim 16

A method as defined in claim 13 wherein said reading angle is approximately 50*.

Claim 17

A method as defined in claim 10 wherein said lamp angle is substantially 0*, said reading angle is substantially 30*, and said plane is substantially perpendicular to said surface.

Claim 18

An instrument for providing an indication of the intensity of the light reflected from a surface, comprising: a housing; means for mounting a lamp in said housing; said housing having an aperture therein; means defining a first light transmission conduit in said housing for directing the light from said lamp to said aperture and onto said surface; means defining a second light transmission conduit in said housing leading away from said aperture for transmitting the light which is reflected by said surface, said light transmission conduits extending at an angle relative to each other; an infrared filter in said first light transmission conduit intermediate said light and said aperture, said infrared filter including heat absorbing glass with a thin hot mirror dielectric coating; a rotatable member within said housing; a lens mounted in said second light transmission conduit intermediate said aperture and said rotatable member; a plurality of filters carried by said rotatable member, said filters being selectively interposable in the path of reflected light transmitted by said second light transmission conduit, at least one of said filters being a color filter; means for providing an indication of a characteristic of the light reflected through said second light transmission conduit; and the light reflected through said second light transmission conduit forming a reading angle with a reference line perpendicular to said surface of from 28* to about 60*.

Claim 19

An instrument for providing an indication of the intensity of the light reflected from a surface, comprising: a housing; means for mounting a lamp in said housing; said housing having an aperture therein; means defining a first light transmission conduit in said housing for directing the light from said lamp to said aperture and onto said surface; means defining a second light transmission conduit in said housing leading away from said aperture for transmitting the light which is reflected by said surface, said light transmission conduits extending at an angle relative to each other; an infrared filter in said first light transmission conduit intermediate said light and said aperture, said infrared filter including heat absorbing glass with a thin hot mirror dielectric coating; a rotatable member within said housing; a lens mounted in said second light transmission conduit intermediate said aperture and said rotatable member; a plurality of filters carried by said rotatable member, said filters being selectively interposable in the path of reflected light transmitted by said second light transmission conduit, at least one of said filters being a color filter; means for providing an indication of a characteristic of the light reflected through said second light transmission conduit; and the light reflected through said second light transmission conduit forming a reading angle with a reference line perpendicular to said surface of from 28* to about 60*.

Claim 20

An instrument as defined in claim 16 wherein the rotatable member substantially circumscribes the lamp and the light from said lamp forms a lamp angle with said reference line of substantially zero degrees.