Opto-electronic line printer having a high density, independently addressable, surface emitting semiconductor laser/light emitting diode array

• US 5,337,074 A
• Filed: 08/05/1991
• Issued: 08/09/1994
• Est. Priority Date: 12/28/1990
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Thornton, Robert L.
• Primary Examiner(s): Fuller, Benjamin R.
• Assistant Examiner(s): YOCKEY, DAVID F
• Application Number:
  US07/740,237
• Time in Patent Office: 1,100 Days
• Field of Search: 346/107 R, 346/108, 346/76 L, 372/50, 372/45, 372/46, 357/17, 257/88, 257/93
• US Class Current: 347/237
• CPC Class Codes: B41J 2/45 using light-emitting diode [LED] or laser arrays
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 33/0062 for devices with an active region comprising only III-V compounds
• CPC Class Codes: H01S 5/423 having a vertical cavity

Abstract

A high density surface emitting semiconductor LED or laser array is coupled with a driver circuit substrate for modulating the light emitted from the array. This modulated light is imaged by optical means onto a photosensitive recording medium of an opto-electronic line printer. The imaging optical means can be either a single or multiple lens system.

Claims

1. An opto-electronic line printer comprising:

a high density, surface emitting, semiconductor light emitting diode array including

a first semiconductor confinement layer deposited on a substrate, said first confinement layer and said substrate having an identical conductivity type,

an active semiconductor layer deposited on said first confinement layer, said active layer providing lightwave generation and propagation,

a second semiconductor confinement layer deposited on said active layer, said second confinement layer having an opposing conductivity type to said first confinement layer and said substrate,

a semiconductor contact layer deposited on said second confinement layer, said contact layer and said second confinement layer having an identical conductivity type,

disordered regions extending through said contact layer, said second confinement layer, said active layer and at least partially through said first confinement layer, said disordered regions having an identical opposing conductivity type to said first confinement layer and said substrate,

contacts formed on said contact layer, one of said contacts aligned with each of said disordered regions,

at least one contact formed on said substrate, and

optical cavities formed between said disordered regions, so that current injected between one of said contacts on said contact layer and said at least one contact on said substrate will cause light emission from one of said optical cavities through the surface of said contact layer,

means for modulating said light emission from said light emitting diode array,

a recording medium, and

optical means aligned between said light emitting diode array and said recording medium for imaging said modulated light emission from said light emitting diode array onto said recording medium.

2. The opto-electronic line printer of claim 1 wherein said optical means is a single lens.

3. The opto-electronic line printer of claim 1 wherein said optical means is a multiple lens system.

4. An opto-electronic line printer comprising:

a high density, surface emitting, semiconductor light emitting diode array including

alternating semiconductor layers deposited on a substrate, said alternating layers forming a distributed Bragg reflector (DBR), said DBR and said substrate having an identical conductivity type,

an active semiconductor layer deposited on said DBR, said active layer providing lightwave generation and propagation,

a semiconductor confinement layer deposited on said active layer, said confinement layer having an opposing conductivity type to said DBR and said substrate,

a semiconductor contact layer deposited on said confinement layer, said contact layer and said confinement layer having an identical conductivity type,

disordered regions extending through said contact layer, said confinement layer, said active layer and at least partially through said DBR, said disordered regions having an identical conductivity type to said DBR and said substrate,

contacts formed on said contact layer, one of said contacts aligned with each of said disordered regions,

at least one contact formed on said substrate, and

optical cavities formed between said disordered regions, so that current injected between one of said contacts on said contact layer and said at least one contact on said substrate will cause light emission from one of said optical cavities through the surface of said contact layer,

means for modulating said light emission from said light emitting diode array,

a recording medium, and

optical means aligned between said light emitting diode array and said recording medium for imaging said modulated light emission from said light emitting diode array onto said recording medium.

5. The opto-electronic line printer of claim 4 wherein said optical means is a single lens.

6. The opto-electronic line printer of claim 4 wherein said optical means is a multiple lens system.

7. An opto-electronic line printer comprising:

a high density, surface emitting, semiconductor laser array including

alternating semiconductor layers deposited on said substrate, said alternating layers forming a first distributed Bragg Reflector (DBR), said first DBR and said substrate having an identical conductivity type,

an active semiconductor layer deposited on said first DBR, said active layer providing lightwave generation and propagation under lasing conditions,

alternating semiconductor layers deposited on said active layer, said alternating layers forming a second distributed Bragg Reflector (DBR), said second DBR having an opposing conductivity type to said first DBR and said substrate,

a semiconductor contact layer deposited on said second DBR, said contact layer and said second DBR having an identical conductivity type,

disordered regions extending through said contact layer, said second DBR, said active layer and at least partially through said first DBR, said disordered regions having an identical conductivity type to said first DBR and said substrate,

contacts formed on said contact layer, one of said contacts aligned with each of said disordered regions,

at least one contact formed on said substrate, and

optical cavities formed between said disordered regions, such that current injected between one of said contacts on said contact layer and said at least one contact on said substrate will cause light emission from one of said optical cavities through the surface of said contact layer,

means for modulating said light emission from said laser array,

a recording medium, and

optical means aligned between said laser array and said recording medium for imaging said modulated light emission from said laser array onto said recording medium.

8. The opto-electronic line printer of claim 7 wherein said optical means is a single lens.

9. The opto-electronic line printer of claim 7 wherein said optical means is a multiple lens system.

10. An opto-electronic line printer comprising:

a high density, surface emitting, semiconductor laser array including

alternating semiconductor layers deposited on a substrate, said alternating layers forming a distributed Bragg reflector (DBR), said DBR and said substrate having an identical conductivity type,

an active semiconductor layer deposited on said DBR, said active layer providing lightwave generation and propagation,

a semiconductor confinement layer deposited on said active layer, said confinement layer having an opposing conductivity type to said DBR and said substrate,

a semiconductor contact layer deposited on said confinement layer, said contact layer and said confinement layer having an identical conductivity type,

disordered regions extending through said contact layer, said confinement layer, said active layer and at least partially through said DBR, said disordered regions having an identical conductivity type to said DBR and said substrate,

dielectric mirrors formed on said nondisordered contact layer,

contacts formed on said contact layer, one of said contacts aligned with each of said disordered regions,

at least one contact formed on said substrate, and

optical cavities formed between said disordered regions, so that current injected between one of said contacts on said contact layer and said at least one contact on said substrate will cause light emission from one of said optical cavities through the surface of said dielectric mirrors,

means for modulating said light emission from said laser array,

a recording medium, and

optical means aligned between said laser array and said recording medium for imaging said modulated light emission from said laser array onto said recording medium.

11. The opto-electronic line printer of claim 10 wherein said optical means is a single lens.

12. The opto-electronic line printer of claim 10 wherein said optical means is a multiple lens system.