Electrostatic latent image apparatus

Claim 2

An electrostatic latent image apparatus comprising: a transparent supporting member having a side through which light energy from a light source may penetrate, and a photosensitive unit on said transparent supporting member having a photoconductive layer and an outer surface that is electrified with an outer surface electric charge which has a polarity, said photosensitive unit having means for forming an electrostatic latent image caused by charge carriers reaching the outer surface; and imagewise exposing means arranged for providing light energy to pass through the side of the transparent supporting member to expose the photoconductive layer of the photosensitive unit and produce imagewise exposure; said photoconductive layer being responsive to the imagewise exposure for producing the carriers to each have an associated polarity and so that the carriers whose associated polarity is opposite to the polarity of the outer surface electric charge each have a mobility that is greater than that for the carriers whose polarity is the same as that of the outer surface electric charge, the photoconductive layer producing the carriers in response to the light energy penetrating the side of the supporting member and then entering the photoconductive layer, said photosensitive unit being mainly made of amorphous silicon with an element added for trapping the electric charge, said element belonging to any of III--a and V--a groups of the periodic table.

Claim 3

An electrostatic latent image apparatus as set forth in claim 1 wherein said photosensitive unit contains 1 to 40 atomic percent of H.

Claim 4

An electrostatic latent image apparatus as set forth in claim 1 wherein B 2 H 6 concentration of said photosensitive unit is 0.2 to 10 ppm.

Claim 5

An electrostatic latent image apparatus as set forth in claim 1, wherein said electrostatic latent image member is positively electrified and said element being added in said photosensitive unit is an element which belongs to the III--a group of the periodic table.

Claim 6

An electrostatic latent image apparatus as set forth in claim 4 wherein B 2 H 6 concentration of said photosensitive unit is 0 to 0.4 ppm.

Claim 7

An electrostatic latent image apparatus as set forth in claim 1 wherein a protecting layer is provided on the outer surface of said photosensitive unit.

Claim 8

An electrostatic latent image apparatus as set forth in claim 1 wherein said photosensitive unit is layered in such order from its outer surface as a surface layer, a photoconductive layer, and a blocking layer.

Claim 9

An electrostatic latent image apparatus as set forth in claim 8 wherein said element for trapping an injected electric charge is added to said surface layer.

Claim 10

An electrostatic latent image apparatus as set forth in claim 8 wherein said element for trapping an injected electric charge belongs to V--a group of the periodic table in positive charge and to III--a group of the periodic table in negative charge.

Claim 11

An electrostatic latent image apparatus as set forth in claim 7 wherein film thickness of said surface layer is 500 Å to 2000 Å.

Claim 12

An electrostatic latent image apparatus as set forth in claim 7 wherein said surface layer has a B 2 H 6 concentration as results from a flow ratio of B 2 H 6 to SiH 4 of 10 to 2000 ppm.

Claim 13

An electrostatic latent image apparatus as set forth in claim 7 wherein film thickness of said photoconductive layer is more than 5000 Å.

Claim 14

An electrostatic latent image apparatus as set forth in claim 1 wherein said photosensitive unit is layered in such order from its outer surface as a photoconductive layer and a blocking layer.

Claim 15

An electrostatic latent image apparatus as set forth in claim 13 wherein said photoconductive layer being added with an element for trapping an injected electric charge.

Claim 16

An electrostatic latent image apparatus as set forth in claim 14 wherein the element for trapping an injected electric charge belongs to V--a group of the periodic table in positive charge and to III--a group of the periodic table in negative charge.

Claim 17

An electrostatic latent image apparatus comprising: a transparent supporting member having a side through which light energy from a light source may penetrate; a photosensitive unit on said supporting member and having a photoconductive layer with an outer surface that is electrified with an outer surface electric charge which has a polarity, said photosensitive unit including forming means for forming an electrostatic latent image caused by charge carriers reaching the outer surface; and imagewise exposing means arranged for providing light energy to pass through the side of the transparent supporting member to expose the photoconductive layer of the photosensitive unit and produce imagewise exposure; said photoconductive layer being responsive to the imagewise exposure for producing the carriers to each have an associated polarity so that the carriers whose associated polarity is opposite to the polarity of the outer surface electric charge have a mobility which is greater than that for the carriers whose associated polarity is the same as the polarity of the outer surface electric charge, said photoconductive layer producing the carriers in response to the light energy penetrating the side of the supporting member and then entering the photoconductive layer, said photosensitive unit being mainly made of amorphous silicon with an element added for trapping the electric charge being injected, said element belonging to any of III--a and V--a groups of the periodic table.

Claim 18

An electrostatic latent image apparatus comprising: a transparent supporting member having a side through which light energy from a light source may penetrate; a photosensitive unit on said supporting member and having a photoconductive layer with an outer surface that is electrified with an outer surface electric charge which has a polarity, said photosensitive unit including forming means for forming an electrostatic latent image caused by charge carriers reaching the outer surface; and imagewise exposing means arranged for providing light energy to pass through the side of the transparent supporting member to expose the photoconductive layer of the photosensitive unit and produce imagewise exposure; said photoconductive layer being responsive to the imagewise exposure for producing the carriers to each have an associated polarity so that the carriers whose associated polarity is opposite to the polarity of the outer surface electric charge have a mobility which is greater than that for the carriers whose associated polarity is the same as the polarity of the outer surface electric charge, said photoconductive layer producing the carriers in response to the light energy penetrating the side of the supporting member and then entering the photoconductive layer, said photosensitive unit being mainly made of amorphous silicon with an element added for trapping the electric charge being injected, said element belonging to any of III--a and V--a groups of the periodic table.

Claim 19

An electrostatic latent image apparatus as set forth in claim 16 wherein said photosensitive unit contains 1 to 40 atomic percent of H.