Aperture designs for facsimile scanning apparatus

Claim 2

Aperture scanning apparatus in a facsimile transmission system comprising: optical mask means in the path of the information modulated light reflected from a document to define the response of the aperture, said mask means having shadow patterns comprising portions with transmissivities defining the absolute values of positive and negative values in accordance with a predetermined calculation of said aperture response.

Claim 3

The apparatus as set forth in claim 1 further including: first light sensitive means for receiving the light transmitted through the portions of said mask means defining the absolute value of the positive value of said aperture response, and second light sensitive means for receiving the light transmitted through the portions of said mask means defining the absolute value of the negative value of said aperture response.

Claim 4

The apparatus as set forth in claim 3 further including: first light transmission means for transmitting the light from said positive value defining portions of said mask means to said first light sensitive means, and second light transmission means for transmitting the light from said negative value defining portions of said mask means to said second light sensitive means.

Claim 5

The apparatus as set forth in claim 3 wherein said first and second light transmission means comprises first and second pluralities of optical fibers, respectively.

Claim 6

The apparatus as set forth in claim 1 wherein the optical transmission characteristic of said optical mask means is in accordance with the absolute value of the relationship (sin pi s/d/ pi s/d) where d is the separation of the scan lines and s is the aperture response independent variable.

Claim 7

The apparatus as set forth in claim 2 wherein said first and second light sensitive means comprise first and second pluralities of photosensors, respectively, in a predetermined array.

Claim 8

In an aperture scanning apparatus for use in a facsimile transmission system, an optical mask in the path of the information modulated light reflected from a document comprising substrate means upon which is recorded a pattern of light and dark areas comprising a shadow pattern with portions having transmissivities defining the absolute values of positive and negative values in accordance with a predetermined response of the aperture.

Claim 9

In an aperture scanning apparatus for use in a facsimile transmission system, an optical mask in the path of the information modulated light reflected from a document comprising substrate means upon which is recorded a pattern of light and dark areas comprising a shadow pattern with portions having transmissivities defining the absolute values of positive and negative values in accordance with a predetermined response of the aperture.

Claim 10

The mask as set forth in claim 7 wherein the optical transmission characteristic of said optical mask is the absolute value of the aperture response, the aperture response having the relationship (sin pi /d/ pi s/d) where d is the separation of the scan lines and s is the aperture response independent variable, the Fourier transform of said aperture response being substantially uniform within the baseband frequency of the facsimile transmission system and substantially zero outside the baseband.

Claim 11

In a facsimile transmission system, the method of improving the overall modulation transfer function thereof, comprising the step of: passing the information modulated light derived from a document prior to photoelectric detection through an optical mask having shadow patterns comprising portions with transmissivities defininG the absolute values of positive and negative values in accordance with a predetermined calculation of the aperture response.

Claim 12

In a facsimile transmission system, the method of improving the overall modulation transfer function thereof, comprising the step of: passing the information modulated light derived from a document prior to photoelectric detection through an optical mask having shadow patterns comprising portions with transmissivities defininG the absolute values of positive and negative values in accordance with a predetermined calculation of the aperture response.

Claim 13

The method as set forth in claim 9 wherein the optical transmission characteristic of said optical mask is the absolute value of (sin pi s/d/ pi s/d ) where d is the separation of the scan lines, and s is the aperture response independent variable.

Claim 14

In a facsimile transmission system, the method of improving the overall modulation transfer function thereof, comprising the step of: modulating the information modulated light obtained in scanning a document to be transmitted by a predetermined aperture response prior to photoelectric detection, the absolute value of said predetermined aperture response being realized by an optical mask having shadow patterns comprising portions with transmissivities defining the absolute values of positive and negative values in accordance with a predetermined calculation of said aperture response.

Claim 15

In a facsimile transmission system, the method of improving the overall modulation transfer function thereof, comprising the step of: modulating the information modulated light obtained in scanning a document to be transmitted by a predetermined aperture response prior to photoelectric detection, the absolute value of said predetermined aperture response being realized by an optical mask having shadow patterns comprising portions with transmissivities defining the absolute values of positive and negative values in accordance with a predetermined calculation of said aperture response.

Claim 16

The method as set forth in claim 11 wherein said predetermined aperture response is defined by (sin pi s/d/ pi s/d) where d is the separation of the scan lines, and s is the aperture response independent variable.

Claim 17

In a facsimile system including a document to be scanned and an illumination source, a multi-aperture facsimile scanner comprising: mask means adjacent a document to be scanned having a light transmission response characteristic of the absolute value of the aperture response, said aperture response being defined by (sin pi s/d/ pi s/d) where d is the separation of the scan lines, and s is the aperture response independent variable, said mask means having shadow patterns comprising portions with transmissivities defining the absolute values of positive and negative values of said aperture response, first light sensitive means for receiving the light transmitted through the portions of said mask means defining the absolute value of the positive values of said aperture response and generating an electrical signal in response thereto, second light sensitive means for receiving the light transmitted through the portions of said mask means defining the absolute value of the negative values of said aperture response and generating an electrical signal in response thereto, and means for combining the outputs of said first and second light sensitive means into a combined electrical signal.

Claim 18

In a facsimile system including a document to be scanned and an illumination source, a multi-aperture facsimile scanner comprising: mask means adjacent a document to be scanned having a light transmission response characteristic of the absolute value of the aperture response, said aperture response being defined by (sin pi s/d/ pi s/d) where d is the separation of the scan lines, and s is the aperture response independent variable, said mask means having shadow patterns comprising portions with transmissivities defining the absolute values of positive and negative values of said aperture response, first light sensitive means for receiving the light transmitted through the portions of said mask means defining the absolute value of the positive values of said aperture response and generating an electrical signal in response thereto, second light sensitive means for receiving the light transmitted through the portions of said mask means defining the absolute value of the negative values of said aperture response and generating an electrical signal in response thereto, and means for combining the outputs of said first and second light sensitive means into a combined electrical signal.

Claim 19

The scanner as set forth in claim 13 further including: first light transmission means adjacent said mask means for transmitting the light response through the portions of said mask means defining the absolute value of the positive values of said aperture response to said first light sensitive means, and second light transmission means adjacent said mask means for transmitting the light response through the portions of said mask means defining the absolute value of the negative values of said aperture response to said second light sensitive means.

Claim 20

The scanner as set forth in claim 13 wherein said first and second light sensitive means comprise first and second pluralities of photosensors, respectively, in a predetermined array.

Claim 21

In a facsimile transmission system a multi-aperture scanner comprising: mask means adjacent a document or the like to be scanned having a shadow pattern of areas with a predetermined optical transmission characteristic defining the absolute value of the aperture response which has positive and negative values, the Fourier transform of said aperture response being substantially uniform within the baseband of spatial frequencies of the facsimile transmission system and substantially zero outside the baseband, first light sensitive means for receiving the light transmitted through certain areas of said mask means and generating a first electrical signal in response thereto, and second light sensitive means for receiving the light transmitted thRough certain other areas of said mask means and generating a second electrical signal in response thereto.

Claim 22

In a facsimile transmission system a multi-aperture scanner comprising: mask means adjacent a document or the like to be scanned having a shadow pattern of areas with a predetermined optical transmission characteristic defining the absolute value of the aperture response which has positive and negative values, the Fourier transform of said aperture response being substantially uniform within the baseband of spatial frequencies of the facsimile transmission system and substantially zero outside the baseband, first light sensitive means for receiving the light transmitted through certain areas of said mask means and generating a first electrical signal in response thereto, and second light sensitive means for receiving the light transmitted thRough certain other areas of said mask means and generating a second electrical signal in response thereto.

Claim 23

The scanner as set forth in claim 16 further including: means for combining the outputs of said first and second light sensitive means into a combined electrical signal.

Claim 24

The scanner as set forth in claim 16 further including: first light transmission means adjacent said mask means for transmitting the light response through said certain areas of said mask means to said first light sensitive means, and second light transmission means adjacent said mask means for transmitting the light response through said certain other areas of said mask means to said second light sensitive means.

Claim 25

The scanner as set forth in claim 18 wherein said first and second light sensitive means comprise first and second pluralities of photosensors, respectively, in a predetermined array.

Claim 26

Aperture scanning apparatus in a facsimile transmission system comprising: optical means having a shadow pattern comprising portions with transmissivities defining the absolute values of a predetermined aperture response in the path of the information modulated light reflected from a document, said transmissivities defining the absolute values of positive and negative values in accordance with a predetermined calculation of said aperture resonse, said optical means including a mask for separating the scanned area into a plurality of sub-areas, first light sensitive means responsive to certain ones of said sub-areas for generating a first electrical signal, second light responsive means responsive to the remainder of said sub-areas for generating a second electrical signal, means for inverting the first electrical signal, and means for adding the inverted signal to said second electrical signal.

Claim 27

Aperture scanning apparatus in a facsimile transmission system comprising: optical means having a shadow pattern comprising portions with transmissivities defining the absolute values of a predetermined aperture response in the path of the information modulated light reflected from a document, said transmissivities defining the absolute values of positive and negative values in accordance with a predetermined calculation of said aperture resonse, said optical means including a mask for separating the scanned area into a plurality of sub-areas, first light sensitive means responsive to certain ones of said sub-areas for generating a first electrical signal, second light responsive means responsive to the remainder of said sub-areas for generating a second electrical signal, means for inverting the first electrical signal, and means for adding the inverted signal to said second electrical signal.

Claim 28

A system as set forth in claim 20 wherein the sensing means each comprise a plurality of photosensors in a predetermined array.

Claim 29

An aperture scanning station in a facsimile transmission system comprising an optical mask having a predetermined optical transmission characteristic which defines the absolute value of the scanning aperture response, said optical transmission characteristic having the absolute values of both positive and negative values of said scanning aperture response, separate means to sense the light passing through the mask from the portions defining the absolute values of the positive and negative values of said aperture response respectively, and means to produce a signal responsive to the difference between the light sensed from the portions defining the absolute values of the positive and negative values of said aperture response.

Claim 30

An aperture scanning station in a facsimile transmission system comprising an optical mask having a predetermined optical transmission characteristic which defines the absolute value of the scanning aperture response, said optical transmission characteristic having the absolute values of both positive and negative values of said scanning aperture response, separate means to sense the light passing through the mask from the portions defining the absolute values of the positive and negative values of said aperture response respectively, and means to produce a signal responsive to the difference between the light sensed from the portions defining the absolute values of the positive and negative values of said aperture response.

Claim 31

A system as set forth in claim 22 comprising first light transmission means for transmitting the light from the portions of the mask defining the absolute value of the positive values to a first sensing means in said separate sensing means and second light transmission means for transmitting the light from the portions of the mask defining the absolute value of the negative value to a second sensing means in said separate sensing means.

Claim 32

A system as set forth in claim 23 wherein the first and second light transmission means each comprise a plurality of optical fibers.

Claim 33

A system as set forth in claim 24 wherein the optical transmission characteristic of the mask is the absolute value of the function (sin pi s/d/ pi s/d) where d is the separation of the scan lines of the scanning station and s is the aperture response independent variable.

Claim 34

A system as set forth in claim 25 wherein the sensing means each produce an electrical signal, and the signal producing means is arranged to produce an output electrical signal equal to the difference between the electrical signals of the sensing means.

Claim 37

A method as set forth in claim 27 wherein the optical transmission characteristic of the mask is the absolute value of the function (sin pi s/d/ pi s/d) where d is the separation of the scan lines and s is the aperture response independent variable.