JPH06140672A - LED print head - Google Patents

Abstract

(57) [Abstract] [Purpose] Interlaced light and the irradiation range on the optical recording material are reduced, and the recording resolution can be improved. A structure is provided in which holes are provided in individual electrodes of a plurality of LED array chips to form exposed surfaces of other conductive semiconductor regions, and holes are provided in individual wires of an optical fiber array plate to form exposed surfaces of the optical fiber array plate. Then, the other conductive type semiconductor region and the exposed surface of the optical fiber array plate are opposed to each other, and the individual electrodes and the individual wirings are brought into contact with each other,
An LED print head having an optical waveguide that optically shields the space between the other conductive type semiconductor region and the exposed surface of the optical fiber array plate from the outside. Also, an LED print head in which a plurality of optical fibers formed by providing a light reflector on the outer surface of the core of the central portion are converged to form an optical fiber array plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic printer in which image information is optically recorded on an optical recording material.
It relates to an ED print head.

[0002]

2. Description of the Related Art In recent years, in LED print heads, a structure in which the LED array chip, which is a main component of the LED print head, and an optical system component have excellent optical characteristics has been studied.

An example of the above-mentioned conventional LED print head will be described below with reference to the drawings.

FIG. 8 is a sectional view of a conventional LED print head. In FIG. 8, reference numeral 51 denotes an LED array chip, and a plurality of LED array chips 51 are linearly arranged in the direction perpendicular to the paper surface. Reference numeral 52 is a semiconductor substrate of one conductivity type, which is an N-type semiconductor in this conventional example, and is common in one LED array chip. Reference numeral 53 denotes another conductive type semiconductor region, which is a P type semiconductor region in this conventional example, and a plurality of other conductive type semiconductor regions 53 are linearly arranged in one LED array chip in the direction perpendicular to the paper surface. Reference numeral 57 denotes a PN junction, which is a junction between the P-type semiconductor region 53 and the N-type semiconductor 52, and emits light by carrier injection and recombination. 54 is an insulating film,
P-type semiconductor region 53, individual electrode 55, and N-type semiconductor 52
The common electrode 56 and the common electrode 56 are electrically separated from each other in a required region, and the holes of the insulating film form exposed surfaces of the P-type semiconductor region 53 and the N-type semiconductor 52. Reference numeral 55 is an individual electrode, which is arranged on the insulating film 54 in the same number as the P-type semiconductor regions 53 at equal pitches in the direction perpendicular to the paper surface, and one end is electrically connected to the P-type semiconductor regions 53 at the hole end of the insulating film. Has been done.
Reference numeral 58 denotes a light emitting surface, which is a region of the P-type semiconductor region 53 that can take out light without the individual electrode 55 in the light transmission direction. 56
Is a common electrode and is the same in one LED array chip, and one end thereof is electrically connected to the N-type semiconductor at the hole end of the insulating film. With the above configuration, one LED element is formed by the N-type semiconductor 52, one P-type semiconductor region 53, the insulating film 54, one individual electrode 55, and the common electrode 56. An optical fiber array plate 60 is formed by sandwiching a plurality of optical fibers 62 between glass substrates 61. One optical fiber 62 is formed by a core 63 at the center, a clad 64 provided on the outer surface of the core 63, and a light absorber 65 provided on the outer surface of the clad 64, and the refractive index of the clad 64 is that of the core 63. It is lower than the refractive index, and the light absorber 65 has a large absorption coefficient with respect to the wavelength band of the light generated in the PN junction 57. Reference numeral 59 denotes a light incident surface, which is a region of the optical fiber array plate 60 including a plurality of optical fibers 62 to which light can be incident. Reference numeral 68 denotes a light emitting surface, which is a region in which the light incident on the light incident surface 59 and transmitted through the optical fiber 62 is emitted. Reference numeral 66 denotes individual wirings, which are arranged in the same number as the plurality of P-type semiconductor regions 53 and at equal pitches in the direction perpendicular to the paper surface. 67 is a common wire which is the same in one LED array chip or one LED array head.

FIG. 9 is a perspective view of a conventional LED array chip constituting the LED print head of FIG. FIG. 10 is a perspective configuration diagram of a conventional optical fiber array plate constituting the LED print head of FIG. 9 and 10 are the same as those shown in FIG. The LED print head shown in FIG. 8 includes an LED array chip 51 shown in FIG. 9 and an optical fiber array plate 60 shown in FIG.
The individual wiring 66 and the individual electrode 55 and the common wiring 67 and the common electrode 56 are brought into contact with each other, and the plurality of LED array chips 51 are connected.
Are linearly arranged on the optical fiber array plate 60. The L of the conventional example configured as described above
The ED print head basically has the LED print head disclosed in Japanese Patent Laid-Open No. 55-98879. The operation will be described below.

First, when a forward voltage is applied between the individual wiring 66 and the common wiring 67, a forward voltage is applied between the individual electrode 55 and the common electrode 56 so that the N-type semiconductor 52 and the P-type semiconductor region 53 are connected. A forward voltage is applied to. At this time PN
Carrier injection occurs at the junction 57, light emission occurs at the PN junction 57 due to carrier recombination, and the light emitting surface 5
Light is emitted from 8. Optical fiber 6 of this synchrotron radiation
The radiated light that has entered the light incident surface 59 at an angle smaller than the critical angle at the interface of the second light incident surface 59 enters the optical fiber 62. Further, of the incident light that has entered the optical fiber 62, the incident light that enters the interface between the core 63 and the clad 64 at an angle equal to or greater than the critical angle at the interface between the core 63 and the clad 64 of the optical fiber 62 is The light is transmitted through the interface of 64 while repeating total reflection, and is emitted from the light emitting surface 68 at the other end of the light incident surface of the optical fiber 62. Record.

[0007]

However, in the above-mentioned structure, the light emitted from one LED element is incident on the optical fiber 62, and the core 63 and the core 63 are formed at an angle less than the critical angle at the interface between the core 63 and the clad 64. The light that has entered the interface of the clad 64 becomes crossed light that crosses the core 63, the clad 64, and the light absorber 65, crosses a plurality of optical fibers 62 while being attenuated by the light absorber 65, and emits light without being attenuated. Since the light emitted from the surface 68 is recorded in the region of the optical recording material corresponding to the other plurality of LED elements, there is a problem that the recording resolution of the optical image information is lowered.

In view of the above problems, the present invention provides an LED print head which suppresses the intersection of optical image information in an optical fiber array plate and realizes high resolution recording on an optical recording material.

[0009]

In order to solve the above problems, the LED print head of the present invention is provided with holes in individual electrodes of an LED array chip to form exposed surfaces of other conductive type semiconductor regions, and By forming a hole in the individual wiring of the fiber array chip to form an exposed surface of the optical fiber array plate, by facing the other conductive type semiconductor region and the exposed surface of the optical fiber array plate to contact the individual electrode and the individual wiring, An optical waveguide is provided that optically shields the periphery of the space between the other conductive type semiconductor region and the exposed surface of the optical fiber array plate from the outside. In addition, by configuring a plurality of optical fibers forming the optical fiber array plate with a light reflector provided on the outer surface of the core in the central portion, the optical fiber is optically connected to the outside except the light incident surface and the light emitting surface. Have been cut off.

[0010]

According to the present invention, with the above-described structure, the light emitted from the PN junction is controlled from being emitted from the light emitting surface of the other conductivity type semiconductor region until reaching the light incident surface of the optical fiber array plate. To be done. In addition, since the light incident on one optical fiber from the light incident surface is transmitted to the light emitting surface without leaking to the outside of the optical fiber, the light of one LED element crosses a plurality of optical fibers and the other light is emitted. The range of irradiation of the area of the optical recording material corresponding to the LED element is narrowed, and the area of the optical recording material corresponding to the other LED is irradiated with the light of the optical recording material corresponding to the LED element emitting light. The area is irradiated and the emission intensity is increased.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An LED print head according to a first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows LE in the first embodiment of the present invention.
FIG. 3 is a cross-sectional view of a D print head. In FIG. 1, reference numeral 2 denotes an LED array chip, and a plurality of LED array chips 2 are arranged in a straight line in a direction perpendicular to the paper surface. 3 is a semiconductor of one conductivity type, which is an N-type semiconductor in this embodiment,
It is common in one LED array chip. Reference numeral 4 denotes another conductivity type semiconductor region, which is a P-type semiconductor region in this embodiment, and a plurality of P-type semiconductor regions 4 are linearly arranged in one LED array chip in the direction perpendicular to the plane of the drawing. Reference numeral 8 denotes a PN junction portion, which is joined to the N-type semiconductor 3 and the P-type semiconductor region 4, and emits light by carrier injection and recombination. An insulating film 5 electrically separates the P-type semiconductor region 4, the individual electrode 6, and the N-type semiconductor 3 and the common electrode 7 in required regions to form exposed surfaces of the P-type semiconductor region 4 and the N-type semiconductor 3. An insulating film hole is provided. Reference numeral 6 denotes a plurality of individual electrodes, which are arranged in the same number as the P-type semiconductor regions 4 in the optical transmission direction of the insulating film 5 in the direction perpendicular to the plane of the drawing, and one end of which is P-type around the hole end of the insulating film. It is electrically connected to the semiconductor region 4.
Reference numeral 9 denotes a light emitting surface, which is an exposed surface of the P-type semiconductor region 4, and is an exposed surface region of the P-type semiconductor region 4 where the individual electrode 6 does not exist in the light transmission direction and light can be extracted. 7 is a common electrode, one L
The same in the ED array chip, and one end of the common electrode 7 is electrically connected to the N-type semiconductor 3 through a hole in the insulating film. With the above structure, one LED array element is formed by the N-type semiconductor 3, one P-type semiconductor region 4, the insulating film 5, one individual electrode 6 and the common electrode 7. Two
Reference numeral 0 denotes an optical fiber array plate, which is formed by sandwiching a plurality of optical fibers 22 between glass substrates 21. Two
Reference numeral 7 denotes a common wiring, which is the same in one LED array chip or one LED print head. Reference numeral 26 denotes individual wirings, which are arranged in the same number as the plurality of P-type semiconductor regions 4 in the direction perpendicular to the plane of the drawing, and holes for individual wirings are formed at one end of the plurality of optical fibers 22.
To form the exposed surface of. Reference numeral 10 is a light incident surface formed of exposed surfaces of the plurality of optical fibers 22 formed by holes of individual wiring. Reference numeral 12 denotes a light emitting surface, which is a region where the light that is incident on the light incident surface 10 and transmitted through the optical fiber 22 is emitted. Reference numeral 23 is a core which is the center of the optical fiber 22. Reference numeral 24 denotes a clad, which is formed on the outer surface of the core 23 and has a refractive index lower than that of the core 23. Reference numeral 25 denotes a light absorber, which is formed on the outer surface of the clad 24 and has a large absorption coefficient with respect to the wavelength band of light emitted at the PN junction 8.

FIG. 2 is a perspective view of the LED array chip constituting the LED print head of the first embodiment shown in FIG. FIG. 3 is a perspective view of the optical fiber array plate of the first embodiment constituting the LED print head of the first embodiment of FIG. 2 and 3, the reference numeral is the same as in FIG.
Is the same as

In the LED print head of FIG. 1, the plurality of individual electrodes 6 of the plurality of LED array chips 2 of FIG. 2 and the individual wirings 26 of the optical fiber array plate 20 of FIG. 26 are joined to face each other, the plurality of LED array chips 2 and the optical fiber array plate 20 are fixed by the insulating resin 11, and the individual electrodes 6, the individual wirings 26, the common electrode 7, and the common wiring 27 are electrically connected, It is physically connected. Further, the light emitting surface 9 and the light incident surface 10
The space between them is surrounded by an optical waveguide 28 formed by the individual electrode 6 and the individual wiring 26, and is optically isolated from the outside.

The operation of the LED print head configured as described above will be described below with reference to FIGS. 1, 4 and 5.

First, when a forward voltage is applied between the individual wiring 26 and the common wiring 27 on the optical fiber array plate 20, a forward voltage is applied between the individual electrode 6 and the common electrode 7, and the P-type semiconductor region 4 is formed. A forward voltage is applied between the N-type semiconductor 3 and the N-type semiconductor 3. At this time, carrier injection occurs in the PN junction portion 8, light is emitted in the PN junction portion 8 due to carrier recombination, and light is emitted from the light emitting surface 9.

FIG. 4 shows the light emitting surface 9 of the P-type semiconductor region 4 and the optical fiber array plate 2 in the first embodiment.
0 and the optical path of the optical recording material, FIG. 5 is the same sectional view in the conventional example, the configuration and the reference numerals in FIG. 4 are the same as those in FIG. 1, and the configuration and the reference numerals in FIG. Is the same as A photosensitive drum 29 records optical image information emitted from a plurality of optical fibers.

Further, 30 is a plurality of parallel lines parallel to the optical transmission direction, 31 is a light beam which repeats total reflection in the core of one optical fiber, and 32 is a light beam which intersects the plurality of optical fibers. , 33 are light rays that are totally reflected by the light incident surface of the optical fiber and become stray light.

Here, at the interface of the light incident surface of the optical fiber,
Let α be the angle of incidence on the light-incident surface of the optical fiber that totally reflects the incident light, and β be the angle of incidence on the light-incident surface of the optical fiber that totally reflects the transmitted light at the interface between the core and the cladding of the optical fiber.
And Further, the angle θ _I is an angle formed by the parallel line 30 and the light beam 31, the angle θ _C is an angle formed by the parallel line 30 and the light beam 32, and the angle θ _O is an angle equal to or larger than the critical angle at the light incident surface of the optical fiber. It is an angle formed by the parallel line 30 and the light ray 33, and each angle satisfies 0 ≦ θ _I ≦ β <θ _C <α ≦ θ _O ≦ π / 2.

Further, it is assumed that the angle formed by the parallel line 30 and any emitted light is θ, the aperture of the optical waveguide 28 is R, and the distance between the P-type semiconductor region 4 and the optical fiber array plate 20 is L. Further, the distance in the scanning direction between the emission position in the P-type semiconductor region 4 of the light 32 emitted from the P-type semiconductor region at the emission angle θ _C and the incident position in the optical fiber array plate is D ₁ , in FIG. 5 is D _0, and the distance in the scanning direction between the incident position on the optical fiber array plate of the light 32 emitted from the P-type semiconductor region at the emission angle θ _C and the incident position on the photosensitive drum 29 is F in FIG. ₁ , F ₀ in FIG. 5, and the distance in the scanning direction between the emission position of the light 32 emitted from the P-type semiconductor region at the emission angle θ _C in the P-type semiconductor region and the incident position on the photosensitive drum 29 is shown in FIG. and T ₀ in T _1, FIG. 5 in.

L of the first embodiment set as described above
The operation of the ED print head will be described below with reference to FIG.

The light emitted from the PN junction 8 is emitted from the light emitting surface 9
Of the emitted light, the light 31 which is incident on the light incident surface 10 of the optical fiber array plate 20 at an angle θ _I with respect to the parallel line 30 is totally reflected at the interface between the core and the clad of one optical fiber 22. Repeatedly transmitted and emitted from the light emitting surface 12 of the optical fiber array plate 20,
Optical image information is recorded in the area on the photosensitive drum 29 that corresponds to each LED element one-to-one. Further, the light 32 emitted from the light emitting surface 9 at an angle θ _C is incident on the light incident surface 10 without being reflected on the surface of the optical waveguide 28 and leaking to the outside,
A plurality of optical fibers 22 while being attenuated by the light absorber 25
The optical image information that has reached the emission port of the optical fiber 22 without being fully attenuated is crossed light (crosstalk light), and the optical image information of a certain LED element is different from that of a plurality of other LEDs.
It is recorded in the area of the photosensitive drum 29 corresponding to the element, and the resolution is lowered. Further, the light 33 which is incident from the light emitting surface 9 at an angle θ _O which is equal to or larger than the total reflection angle of the optical fiber is the optical waveguide 28.
The light is totally reflected within the light incident surface 10 without being reflected on the surface where the light is formed and leaking to the outside, and does not enter the optical fiber 22 and becomes stray light.

Here, a comparison between the effect and the conventional example will be shown with reference to FIGS. 4 and 5. In the LED print head of the first embodiment shown in FIG. 4, P is set at an angle θ _C that is equal to or greater than the critical angle.
The light emitted from the p-type semiconductor region 4 satisfies the following equation: D ₁ <R, and the distance D in the scanning direction between the emission position of the p-type semiconductor region 4 and the incidence position of the optical fiber array plate 20.
₁ is not related to the emission angle in the P-type semiconductor region, but in the conventional LED print head shown in FIG. 5, the light emitted from the P-type semiconductor region 4 at an angle θ _C equal to or greater than the critical angle is D ₀ = L × TAN (θ _C ) The distance D _{0 in} the scanning direction between the emission position of the P-type semiconductor region 53 and the incident position of the optical fiber array plate 60 changes according to the incident angle θ _C , and θ _C > TAN. (R / L) In the θ _C range that satisfies the above formula, D ₁ of the LED print head of the first embodiment is smaller than D ₀ of the LED print head of the conventional example, and D ₁ <D ₀ F ₁ of the example LED print head and F ₀ of the conventional LED print head are equal, and F ₁ = F ₀ . Therefore, the distance in the scanning direction between the emission position of the light 32 emitted from the P-type semiconductor region at the emission angle θ _C in the P-type semiconductor region and the incident position on the photosensitive drum 29 is D ₁ + F ₁ <D ₀ + F ₀ From the formula, the distance T, which is the sum of the distance D and the distance F, is T ₁ <T _0, where the distance T represents the distance between the light emitting position of the LED element and the recording position of the optical recording material. The range where the confusion light of the LED print head is recorded on the photosensitive drum 29 is narrower than the range where the cross light of the conventional LED print head is recorded, and the resolution of the LED print head of the first embodiment is improved. I mean. In particular, R / L <TAN {SIN ^-1 (A / N)} LED having a diameter R of an optical waveguide satisfying the above formula and a distance L between the P-type semiconductor region 4 and the optical fiber array plate 20.
In the print head, the above effect is effective for all the intersecting lights. Further, by increasing the numerical aperture A of the optical fiber 22, a larger light emission intensity can be obtained, but in the LED print head of the conventional example, the cross light also increases, but in the LED print head of the present invention, Between the P-type semiconductor region 4 and the optical fiber array plate 20, the optical waveguide 28 does not intersect with the other optical fibers 22, so the optical fiber 22
The emission intensity can be increased as the numerical aperture A is increased.

A second embodiment of the present invention will be described below with reference to the drawings. FIG. 6 is a sectional view of an LED print head according to the second embodiment of the present invention.

The difference between the LED print head of the first embodiment shown in FIG. 1 and the LED print head of the second embodiment shown in FIG. 6 lies in the optical fiber 22 in FIG.
The clad 24 is formed on the outer surface of the core 23, and the light absorber 25 is formed on the outer surface of the core 23. Instead, the light reflector 43 is formed on the outer surface of the core 42. The characteristic configuration of the second embodiment will be described below.

In FIG. 6, reference numeral 41 is an optical fiber array plate, and a plurality of optical fibers 44 are connected to a glass substrate 45.
It is sandwiched between them. Reference numeral 42 is a core which is the center of the optical fiber 44. 43 is a light reflector, the core 4
It is formed on the outer surface of No. 2 and has a large reflection coefficient with respect to the wavelength band of the light emitted from the PN junction 8. The LED print head in the second embodiment has the same structure and operation as the LED array chip of the first embodiment except for the optical fiber 44.

FIG. 7 is a sectional view showing the light emitting surface 9 of the P-type semiconductor region 4, the optical fiber array plate 41, and the optical path in the second embodiment of the optical recording material. In FIG. 10, 41 is an optical fiber. The array plate 44 is an optical fiber forming the optical fiber array plate 41,
42 is a core at the center of the optical fiber 62, and 43 is a light reflector. Reference numeral 46 is a light incident surface composed of a plurality of optical fibers 44, and 47 is a light emitting surface composed of a plurality of optical fibers. 30 is a plurality of parallel lines parallel to the optical transmission direction, 31, 3
2 and 33 are the same light rays as in FIG. 4 of the first embodiment and FIG. 5 of the conventional example, and the angles θ _I , θ _C , and θ _O are also the same in FIG. 4 of the first embodiment and the conventional example. The angle is the same as in FIG. 5, and 0 ≦ θ _I ≦ β <θ _C <α ≦ θ _O ≦ π / 2 is satisfied.

The angle formed by the parallel line 30 and the emitted light is θ, the aperture of the optical waveguide 28 is R, the distance between the P-type semiconductor region 4 and the optical fiber array plate 41 is L, and the emission angle θ _C.
The distance in the scanning direction between the emission position of the light 32 emitted from the P-type semiconductor region 4 at the P-type semiconductor region 4 and the incident position at the optical fiber array plate 41 is D ₂ , and the emission angle θ _C is the P-type semiconductor region. The distance in the scanning direction between the incident position on the optical fiber array plate 41 and the incident position on the photosensitive drum 29 of the light 32 emitted from the laser beam 4 is F ₂ . The distance in the scanning direction between the emission position of the light 32 emitted from the P-type semiconductor region 4 at the emission angle θ _C in the P-type semiconductor region 4 and the incident position on the photosensitive drum 29 is T ₂ .

L of the second embodiment set as described above
The operation specific to the second embodiment of the ED print head will be described below with reference to FIG.

The light emitted from the PN junction 8 is emitted from the light emitting surface 9
Of the emitted light, which is incident on the optical fiber array plate 41 at an angle θ _I with respect to the parallel line 30
Is transmitted while repeating reflection at the interface between the core 42 of one optical fiber 44 and the light reflector 43, is emitted from the light emitting surface 47, and is emitted to the area on the photosensitive drum 29 corresponding to each LED element one-to-one. Record image information. Further, the light 32 emitted from the light emitting surface 9 at the angle θ _C is incident on the light incident surface 10 without being reflected by the surface of the optical waveguide 28 and leaking to the outside, and is transmitted to the core 42 of one optical fiber 44 and the light. The light is repeatedly transmitted from the interface of the reflector 43 and emitted from the light emitting surface 47 without crossing, and the optical image information is recorded on the photosensitive drum 29. Further, the light 33 emitted by than the angle theta _O light emitting surface 9 without leaking to the outside is reflected by the surface of the optical waveguide 28 is totally reflected by the light incident surface 10, the stray light does not enter the optical fiber 44 Becomes

Here, the effects of the second embodiment will be compared with the conventional example and the first embodiment with reference to FIGS. 4, 5 and 7. In the LED print head of the second embodiment shown in FIG. 7, the light emitted from the P-type semiconductor region 4 at an angle θ _C equal to or greater than the critical angle satisfies the following formula: D ₂ <R Similar to the example LED printhead. Therefore, in the θ _C range where θ _C > TAN (R / L) above is satisfied, D ₂ of the LED print head of the first embodiment becomes smaller than D ₀ of the LED print head of the conventional example, and D ₂ = D ₁ <D _{0 Since} the light incident on the optical fiber 62 in FIG. 7 does not intersect regardless of the incident angle, F ₂ <F ₁ = F ₀ . Therefore, the distance in the scanning direction between the emission position in the P-type semiconductor region of the light 32 emitted from the P-type semiconductor region at the emission angle θ _C and the incident position on the photosensitive drum 29 is D ₂ + F ₂ <D ₁ + F ₁ < D ₀ + F _{0 From the} above equation, the distance T, which is the sum of the distance D and the distance F, is T ₂ <T ₁ <T ₀ where the distance T is the distance between the light emitting position of the LED element and the recording position of the optical recording material. The range in which the confusion light of the LED print head of the second embodiment is recorded on the photosensitive drum 29 is narrower than the range of the cross light of the LED print head of the first embodiment. It is meant to improve the resolution of the example LED printhead.

As described above, by providing the light reflector on the outer surface of the core at the center of the optical fiber, the crossed light is completely eliminated and the resolution of the formation of the optical image information is improved.

In the first and second embodiments, the individual electrode holes 19 and the individual wiring holes have the same diameter, but the individual electrode holes 19 and the individual wiring holes do not have to have the same diameter.

Further, in the first and second embodiments, the common electrode 7 is formed on one main surface of the same N-type semiconductor substrate as the P-type semiconductor region 4, but it may be formed on the other main surface. Good.

In the first and second embodiments, L
Although the insulating resin 11 for fixing the ED array chip to the optical fiber array plate is formed outside the optical waveguide 28, it may be formed inside the optical waveguide 28. In addition, when the insulating resin 11 is formed both inside and outside the optical waveguide 28, the insulating resin inside the optical waveguide 28 and the insulating resin outside the optical waveguide may not be the same. It is preferable that the insulating resin is transparent and the insulating resin outside the optical waveguide has a large absorption coefficient. Further, as the refractive index of the insulating resin filled in the optical waveguide 28 is made larger than 1, the P-type semiconductor region 4 is formed.
The extraction efficiency of light from the can be increased.

[0036]

As described above, according to the present invention, by providing the optical waveguide composed of the individual electrodes and the individual wirings between the light emitting surface of the other conductivity type semiconductor region and the light incident surface of the optical fiber array plate, the crossed light can be obtained. Also, the irradiation range on the optical recording material is reduced, and the recording resolution can be improved. Also,
By forming an optical fiber by providing a light reflector on the outer surface of the core in the central portion, interlaced light in the optical fiber array plate is eliminated, and the recording resolution can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an LED print head according to a first embodiment of the present invention.

FIG. 2 is a perspective configuration diagram of an LED array chip in the example.

FIG. 3 is a perspective configuration diagram of an optical fiber array plate in the example.

FIG. 4 is a perspective view of an LED print head according to the embodiment.

FIG. 5 is a perspective view of an LED print head in a conventional example.

FIG. 6 is a sectional view of an LED print head according to a second embodiment of the present invention.

FIG. 7 is a perspective view of the LED print head according to the embodiment.

FIG. 8 is a cross-sectional view of an LED print head in the conventional example.

FIG. 9 is a perspective configuration diagram of an LED array chip in the conventional example.

FIG. 10 is a perspective configuration diagram of an optical fiber array plate in the conventional example.

[Explanation of symbols]

 2 LED array chip 3 One conductivity type semiconductor 4 Other conductivity type semiconductor region 5 Insulating film 6 Individual electrode 7 Common electrode 8 PN junction 9 Light emitting surface 10 Light incident surface 11 Insulating resin 12 Light emitting surface 20 Optical fiber array plate 21 Glass substrate 22 Optical fiber 23 Core 24 Clad 25 Light absorber 26 Individual wiring 27 Common wiring 28 Optical waveguide 29 Photosensitive drum 30 Parallel line 31 Transmission light 32 Interlaced light 33 Stray light 41 Optical fiber array plate 42 Core 43 Light reflector 44 Light Fiber 45 Glass substrate 46 Light incident surface 47 Light emitting surface 51 LED array chip 52 One conductive type semiconductor 53 Other conductive type semiconductor region 54 Insulating film 55 Conventional individual electrode 56 Common electrode 57 PN junction 58 Light emitting surface 59 Light incident surface 60 optical fiber array plate 61 glass substrate 2 the optical fiber 63 core 64 cladding 65 light absorber 66 individual wires 67 common wiring 68 light emitting surface

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B41J 2/455 G02B 27/00 J 9120-2K

Claims (2)

[Claims] 1. A plurality of other conductivity type semiconductor regions are linearly provided on one main surface of a one conductivity type semiconductor substrate, an insulating film is formed on one major surface of the one conductivity type semiconductor, and a predetermined region of the insulating film is formed. A plurality of insulating film holes are provided in the first conductive semiconductor layer to form an exposed surface of the one conductivity type semiconductor and the plurality of other conductivity type semiconductor areas, and a plurality of individual electrodes are formed on the exposed surface of the other conductivity type semiconductor area. A plurality of LED array chips provided so as to be connected over the entire circumference, forming an exposed surface of the other conductive type semiconductor region, and providing a common electrode on the exposed surface of one main surface of the one conductive type semiconductor substrate; A clad on the outer surface of the core of the part, and an optical fiber array plate formed by converging a plurality of optical fibers provided with a light absorber on the outer surface of the clad on one main surface perpendicular to the optical transmission direction , Common wiring and multiple individual wiring, The individual wirings are provided with the same number of the plurality of other conductivity type semiconductor regions, and an optical fiber array plate formed at an equal pitch, the plurality of individual electrodes and the plurality of individual wirings are in contact with each other, and the plurality of LED arrays are provided. In an LED print head in which chips are linearly arranged on one main surface of the optical fiber array plate, the optical fiber array plate is surrounded by the individual wiring at a position facing the exposed surface of the other conductive semiconductor region. An LED printhead having an exposed closed area of. 2. A plurality of other conductivity type semiconductor regions are linearly provided on one main surface of one conductivity type semiconductor substrate, an insulating film is formed on one major surface of the one conductivity type semiconductor, and a predetermined region of the insulating film is formed. A plurality of insulating film holes are formed on the first main surface of the one conductivity type semiconductor to form an exposed surface of the plurality of other conductivity type semiconductor regions. A plurality of LED array chips provided with electrodes and provided with individual electrodes on the exposed surface of the other conductive type semiconductor region, and an optical fiber array plate formed by converging a plurality of optical fibers, which is perpendicular to the optical transmission direction. A common wiring and a plurality of individual wirings are provided on the main surface, and the plurality of the individual wirings are provided in the same number as the plurality of other conductivity type semiconductor regions, and an optical fiber array plate formed at an equal pitch. Abutting the individual electrodes and a plurality of the individual wires, In an LED print head in which a number of the LED array chips are linearly arranged on one main surface of the optical fiber array plate, a plurality of optical fibers forming the optical fiber array plate are provided on an outer surface of a core in a central portion. LED provided with a light reflector
Print head.