LED ARRAY, LED HEAD AND IMAGE RECORDING APPARATUS

Abstract

An LED array includes a semiconductor substrate and a plurality of first LED portions formed integrally on a surface of the semiconductor substrate. The first LED portions emit light of a predetermined color. The LED array includes a plurality of second LED portions fixed to the semiconductor substrate and are disposed corresponding to the first LED portions. The second LED portions emit light whose color is different from the first LED portions The second LED portions are so disposed that active layers of the second LED portions are substantially at the same height as active layers of the first LED portions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

In the attached drawings:

FIG. 1A is a plan view illustrating an LED array according to Embodiment 1 of the present invention;

FIG. 1B is a sectional view illustrating a red LED portion of the LED array R, taken along line IB-IB in FIG. 1A;

FIG. 1C is a sectional view illustrating a green LED portion of the LED array G, taken along line IC-IC in FIG. 1A;

FIGS. 2A through 2D illustrate a manufacturing process of the red LED portions R according to Embodiment 1;

FIGS. 3A through 3C illustrate a manufacturing process of the green LED portions G according to Embodiment 1;

FIGS. 4A through 4C illustrate a manufacturing process of blue LED portions B according to Embodiment 1;

FIGS. 5A through 5C illustrate a fixing process of the green LED portions G according to Embodiment 1;

FIGS. 6A through 6C illustrate a fixing process of the blue LED portions B according to Embodiment 1;

FIG. 7 is a plan view illustrating a process for forming an insulation film according to Embodiment 1;

FIG. 8 is a plan view illustrating a process for forming an organic insulating portion according to Embodiment 1;

FIG. 9 is a plan view illustrating a process for forming bonding pads according to Embodiment 1;

FIG. 10 illustrates a relationship among dimensions, gaps and resolutions of respective LED portions;

FIG. 11 is a plan view illustrating a modification of the LED array according to Embodiment 1;

FIGS. 12A and 12B illustrate a relationship between gaps between the LED portions R and G and emitted lights from the LED portions R and G according to the modification of Embodiment 1;

FIGS. 13A and 13B illustrate emitted lights from the LED portions R and G when the LED portions R and G are disposed proximate to each other, according to the modification of Embodiment 1;

FIG. 14 illustrates emitted lights from the LED portions R and G when lenses are provided to focus lights emitted by the LED portions R and G, according to the modification of Embodiment 1;

FIG. 15A is a plan view illustrating an LED array according to Embodiment 2 of the present invention;

FIG. 15B is a sectional view illustrating the LED array according to Embodiment 2, taken along line XVB-XVB shown in FIG. 15A;

FIG. 16 is a plan view illustrating an LED array according to Embodiment 3 of the present invention;

FIGS. 17A and 17B illustrate a relationship between gaps among the LED portions R, G and B and emitted lights, according to Embodiment 3;

FIG. 18 illustrates emitted lights from the LED portions R, G and B when the LED portions R, G and B are disposed proximate to one another, according to Embodiment 3;

FIG. 19 illustrates emitted lights when lenses are provided to focus lights emitted by the LED portions R, G and B, according to Embodiment 3;

FIG. 20A is a plan view illustrating an LED array according to Embodiment 4 of the present invention;

FIG. 20B is a sectional view illustrating the LED array according to Embodiment 4, taken along line XXB-XXB shown in FIG. 20A, and

FIG. 21 is a schematic sectional view illustrating an image recording apparatus according to Embodiments of the present invention.

Claims

1. An LED array comprising: a semiconductor substrate;a plurality of first LED portions formed integrally on a surface of said semiconductor substrate, said first LED portions emitting light of a predetermined color, anda plurality of second LED portions fixed to said semiconductor substrate and disposed corresponding to said first LED portions, said second LED portions emitting light whose color is different from said first LED portions,wherein said second LED portions are so disposed that active layers of said second LED portions are substantially at the same height as active layers of said first LED portions.

2. The LED array according to claim 1, wherein said second LED portions are fixed to regions of said semiconductor substrate which are different in height from regions of said semiconductor substrate on which said first LED portions are integrally formed.

3. The LED array according to claim 1, wherein said first LED portions include red LED portions, wherein said second LED portions include at least one of green LED portions and blue LED portions.

4. The LED array according to claim 1, wherein said first LED portions and second LED portions are substantially linearly arranged.

5. The LED array according to claim 1, wherein said first LED portions include red LED portions, and said second LED portions include green LED portions and blue LED portions, and wherein said red LED portion, said blue LED portion and said green LED portion are disposed on vertexes of a triangle.

6. The LED array according to claim 1, wherein said semiconductor substrate has an insulation film formed on a surface thereof and bonding electrodes provided on said insulation film, wherein said second LED portions have electrodes formed on a surface thereof, andwherein said second LED portions are fixed to said semiconductor substrate in such a manner that said electrodes of said second LED portions contact said bonding electrodes of said semiconductor substrate.

7. The LED array according to claim 6, further comprising bonding pads electrically connected to said bonding electrodes, and other bonding pads electrically connected to transparent electrodes formed on upper surfaces of said second LED portions.

8. The LED array according to claim 1, further comprising a plurality of bonding pads formed on said semiconductor substrate, which are electrically connected to anode side electrodes and cathode side electrodes of said first LED portions and said second LED portions.

9. An LED array comprising: a semiconductor substrate;a plurality of first LED portions formed integrally on a surface of said semiconductor substrate, said first LED portions emitting light of a predetermined color, anda plurality of second LED portions respectively layered on said first LED portions, said second LED portions emitting light whose color is different from said first LED portions,wherein said second LED portions are in the form of thin films.

10. An LED head comprising: an LED array according to claim 1, anda driving circuit that controls said first LED portions and said second LED portions in accordance with image data.

11. An LED head comprising: an LED array according to claim 9, anda driving circuit that controls said first LED portions and said second LED portions in accordance with image data.

12. An image recording apparatus comprising: an LED head according to claim 10, anda feeding portion that feeds a photosensitive material in an auxiliary scanning direction, said photosensitive material being exposed with lights of respective colors emitted by said LED head.

13. An image recording apparatus comprising: an LED head according to claim 11, anda feeding portion that feeds a photosensitive material in an auxiliary scanning direction, said photosensitive material being exposed with lights of respective colors emitted by said LED head.