JPH0985986A - Led printing head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED printing head to be easily assembled with excellent light emission properties. SOLUTION: This LED printing head is composed of a grooved printed circuit board 18 with plural grooves 20 formed on the light emitting end side of an end light emitting-type LED array, and further, projecting parts 24 formed in such a way that the projecting parts 24 are engaged with the grooves 20 under a state of non-interruption and non-reflection to an emergent light from the array.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to LED printheads.

[0002]

2. Description of the Related Art As a conventional LED print head,
For example, there is one disclosed in JP-A-2-125765. In this LED print head, an edge emitting LED array is provided on the upper surface of the wiring board. An N electrode is provided on the upper surface of the LED array, while a P electrode is provided on the lower surface. An inverted S-shaped support member is attached to the substrate to fix the LED array. Since the support member supports the LED array so that the light emitting surface of the LED array is perpendicular to the surface of the wiring board, the direction in which light is emitted from the LED array is parallel to the surface of the wiring board and the light transmission efficiency is improved. It is reported that the

[0003]

However, the above-mentioned LED print head uses the edge-emitting LED array. Then, this LED array is mounted near the end surface of the wiring board together with other various components (driver IC, etc.). For this reason, since a thermosetting resin or the like is used to fix various components to the board, stress is generated between the resin and the board when the components are fixed to the wiring board, and the light emitting end surface of the board on which the LED array is mounted is mounted. The board part on the side is warped. As a result, there is a problem that the light emitting portion of the LED array is not aligned in a straight line with respect to the surface of the photosensitive drum.
In order to arrange the light emitting portions of the LED array in a straight line, it is necessary to correct the warped portion of the wiring board and flatten the board. For that purpose, an auxiliary member is required. However, when the auxiliary member is provided on the light emitting side of the LED array, there is a possibility that a so-called unnecessary spot may occur due to the light emitting spot having a reduced light emission intensity due to light blocking or a blur due to reflection.

Therefore, it has been desired to develop an LED print head which is easy to assemble and has good light emission characteristics.

[0005]

Therefore, according to the present invention, a plurality of edge emitting LED arrays, a wiring board on which the LED arrays are mounted, and a converging unit for condensing light emitted from the LED arrays. In an LED print head including a solid rod lens array, the above-mentioned wiring board is a grooved wiring board having a plurality of groove portions on the light emitting end face side of each edge emitting LED array, and further, each edge emitting LED described above. It is characterized in that the head holder is provided with a convex portion that is fitted to the groove portion in a non-blocking and non-reflecting state with respect to incident light from the array to the converging rod lens array.

As described above, by providing the convex portion of the head holder at a position facing the groove portion and fitting them together, in the case of the grooved wiring board on which the edge emitting LED array is mounted in advance, the groove portion is formed. It is possible to correct the warp that has occurred in the attached wiring board, or to prevent the occurrence of the warp by connecting the wiring board and the head holder in advance by fitting the groove portion and the convex portion, and then the wiring board. It is also possible to mount an LED array on top. For this reason, the light emitting portions of the edge emitting LED array mounted on the substrate are aligned with the surface of the photosensitive drum in a straight line, so that the light emitting dots can be turned on in a straight line.

Further, when the edge-emitting LED array is caused to emit light, the emitted light spreads due to the diffraction phenomenon at the light-emitting end face. Of the spread emitted light, the light is emitted within a converging range of the converging rod lens array. Since the groove and the projection are fitted so that the received light does not hit not only the head holder itself but also the projection of the head holder, the light emission intensity due to light shielding is reduced, and unnecessary spots such as blurred spots due to reflection Can be prevented.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an optical print head of the present invention, a wiring board used for the same, and a head holder will be described below with reference to the drawings. The figure shows
The sizes, shapes, and positional relationships of the respective constituents are only schematically shown so that the present invention can be understood.

First, FIGS. 1A and 1B are a plan view and a front view seen from the light emitting end surface side for explaining the structure of the edge emitting LED array of the present invention.
FIG. 2 is a diagram showing a part of a cross section of an edge-emitting LED array taken along line XX in FIG. 1 (A).

The LED print head of the present invention comprises a plurality of edge emitting LED arrays, a wiring board on which the LED arrays are mounted at non-blocking and non-reflecting positions of light emitted from the LED arrays, and light emitted from the LED arrays. And a focusing rod lens array for condensing light. Here, first, the edge emitting LED array will be described.

In this example, a plurality of p diffusion layers 12 are provided on an n layer (n-GaAsP) substrate 10. In addition, substrate 1
A diffusion prevention film 11 and an insulating layer 13 are provided on the surface of the diffusion barrier layer 0, and a p electrode 14 is provided so as to cover part of the p diffusion layer 12, the surfaces of the diffusion prevention film 11 and the insulating layer 13. On the other hand, an n electrode 16 is provided on the back surface of the base material 10. Therefore, the p-electrode 1
4 by applying a voltage between the n-electrode 16 and the
A current flows from the electrode 14 side to the n electrode 16 side, and the p diffusion layer 1
It can emit light from 2. In addition, one P diffusion layer 1
2, the base material 10, the diffusion prevention film 11, the insulating layer 13,
One LED element is composed of the p-electrode 14 and the n-electrode 16, and each edge-emitting LED array (hereinafter, also simply referred to as an LED array) of this embodiment includes a plurality of LED elements. In addition, the base material 10 is each LE
It is commonly used for each LED element in the LED array for each D array. Here, the structure of the LED near the light emitting end face will be described in some detail with reference to FIGS. 1 and 2.

A step portion is provided at an upper corner of the base material 10 on the light emitting portion side. The step portion has a flat portion 10b orthogonal to the end face 10a and an inclined surface 10c extending from the flat portion 10b to the upper surface of the base material. have. The light emitting surface 12a is exposed on the inclined surface 10c protruding to the upper surface of the step portion, and the p diffusion layer 12 is provided. In this example, the end surface 1 of the p diffusion layer 12 on the light emitting portion side is formed.
The horizontal distance from 0a to the lower part of the light emitting surface 12a of the diffusion layer 12 forming a part of the inclined surface 10c is L _1, and
The vertical distance from the lowermost surface of the diffusion layer 12 to the flat surface 10b which is the lower step surface of the step portion of the substrate 10 is D ₁ .

Further, the converging angle of the imaging optical system when the LED array is made to emit light (here, the converging angle θ is the light flux of the light beam emitted from the light source of the LED array and entering the condensing system of the substrate 10). The maximum angle of spread from the direction parallel to the flat surface 10b) is θ.

Next, referring to this FIG.
A method of forming the LED array portion of the ED print head will be briefly described.

In this example, the diffusion preventive film 11 having an opening (not shown) on the surface of the substrate 10 by the photolithography method.
To form Impurities such as zinc (Zn) are selectively diffused from the openings of the diffusion prevention film 11 to form the p diffusion layer 12. Here, an alumina film is used as the diffusion prevention film 11,
A nitride film or a silicon oxide film is used, and the film thickness is 50-
It is 100 nm.

Next, the p diffusion layer 12 in the opening and a part of the base material 10 are removed by etching to form a step portion at the upper corner of the light emitting side base material. The step portion is also referred to as a mesa portion here. As the etchant liquid at this time, a sulfuric acid-based solution or a hydrofluoric acid-based solution is suitable. However, other etching solutions or dry etching methods may be used as long as they have the same effect as sulfuric acid-based or hydrofluoric acid-based. The wall surface of the etched groove is inclined in an oblique direction.
The inclination angle φ of c is about 50 degrees with respect to the horizontal direction.

The step portion of the base material 10 is usually (1)
The step distance D ₁ is determined so as to satisfy the formula, and the diffusion layer 12
The light emitted from, that is, all or part of the emitted light is prevented from being blocked or reflected by the surface of the base material 10, here the flat surface 10b.

D ₁ ≧ L ₁ × tan θ (0 ≦ θ ≦ 90 °) (1) Next, the insulating layer 13 is formed on the diffusion prevention film 11 by using any suitable method, and then, Diffusion prevention film 11, insulating layer 13
And the P electrode 14 which covers a part of the diffusion layer 12 formed on the base material is formed.

Next, with reference to FIGS. 3 and 4, a method of fitting the grooved wiring board used in the LED print head and the head holder and a fixing shape after fitting will be described.

FIG. 3 is a perspective view for explaining a method of fixing the grooved wiring board 18 and the head holder 25.
4A and 4B show the wiring board with groove 18
After fixing the head holder 25 and the head holder 25, the structure of FIG.
It is a figure which shows the cross section which appears when it cut | disconnects in the arrow direction of-Y line. In addition, in FIGS. 4A and 4B, two fixing portions for the groove portion of the substrate and the convex portion of the head holder are shown, but actually, the same number of fixing portions as the groove portions 20 of FIG. Has been formed. Further, the grooved wiring board 18 and the head holder 2
5 and 5 (here, fitting means a state in which the groove portion and the convex portion are fitted together so that the grooved wiring board 18 and the head holder 25 do not rattle and do not move firmly). After mounting a plurality of LED arrays on the grooved wiring substrate 18 in advance, the substrate 18 is mounted on the head holder 25.
Although it is preferable to fix the LED array 1 on the grooved wiring substrate 18 here for simplification of explanation,
The description will be made in the state where the No. 5 is not mounted.

In this example, as the grooved wiring board 18, a composite member made of epoxy resin or bismaleidotriazine resin (also abbreviated as BT), glass cloth or resin, and porous ceramic is used. Therefore, the surface of the grooved wiring substrate 18 can be processed with good flatness. However, as already explained, the substrate 18 is actually
A plurality of LED arrays and driver ICs for driving are mounted on. Therefore, if these components are fixed to the substrate 18 using a thermosetting resin, stress is generated between the thermosetting resin to be used and the grooved wiring substrate 18 under the influence of the heat at the time of fixing. The grooved wiring board 18 is warped.
In order to correct the warp of the board 18, the present invention uses a method of fixing the head holder 25 to the wiring board 18. In this example, a plurality of groove portions 20 having the same size are provided at the same pitch on the end surface of the grooved wiring board 18 on which the LED array is mounted, and the end surface is formed in exactly the comb tooth shape 12. On the other hand, the head holder 25 is an L-shaped base body 2
2 and the convex portion 24, and the convex portion 24 is formed on the base body 22 at a position facing the groove portion 20. The convex portion 24 is formed so as to fit in the groove portion 20, and the fitted convex portion 24 does not completely or partially block or reflect the light emitted from the LED. It fits in the groove 20. Note that, here, the L-shaped base body 22 and the convex portion 24 are collectively referred to as a head holder 25. Therefore, the same number of protrusions 24 as the groove portions 20 are provided on the base body 22. In this embodiment, the width S of the convex portion 24 is formed to be slightly wider than the groove width W (see FIG. 3). By fitting the groove 20 of the grooved wiring board 18 into the protrusion 24 of the base body 22, the warp of the wiring board 18 is corrected and the mounting surface of the LED array of the wiring board 18 becomes a flat surface.

FIGS. 4A and 4B are views showing a cross section of the fixing portion after fixing the grooved wiring substrate 18 and the head holder 25.

In the configuration example shown in FIG. 4A, the groove portion 20 of the grooved wiring board 18 is formed in a drawing shape having a wall perpendicular to the thickness direction of the wiring board 18, and the groove portion 20 is formed. The convex portion 24 opposed to is formed in a rectangular column shape having a width S slightly wider than the width W of the groove portion 20 in at least one direction (see FIG. 3). Therefore, the grooved wiring board 1
When the groove portion 20 of No. 8 is fitted into the convex portion 24 provided on the base body 22, the contact frictional resistance between the side surface of the groove portion 20 and the side surface of the convex portion 24 becomes large, so that both are substantially fixed. . Further, preferably, the corners of the upper surface of the convex portion 24 are trimmed so that the convex portion is not damaged and the groove portion 2 of the grooved wiring board 18 is formed.
It can be easily fitted into 0.

In the example of FIG. 4B, the grooved wiring board 18 is used.
A tapered inclined surface is formed on the side wall surface of the groove portion 20, and the groove portion 20 is formed so that the groove width on the substrate surface on the LED non-mounting side is narrower than that on the substrate surface on the LED mounting side.
On the other hand, the convex portion 2 of the base body 22 facing the groove portion 20
4 is formed so that the hem width is narrower than the tip width. Therefore, in FIG. 4B, when the groove portion 20 and the convex portion 24 of the wiring board with groove 18 are fixed, the caulking strength is further increased as compared with the method of fixing the structure of FIG. 4A.

Next, referring to FIGS. 5 to 7, the LED when the edge emitting LED array is mounted on the grooved wiring board 18 in advance and the board 18 is fixed to the head holder 25.
The schematic structure of the print head will be described. The LED array mounted on the grooved wiring board 18 is the grooved wiring board 1.
8 are provided so as to be arranged between the groove portions 20, and
5 and 6, the driver IC is omitted, but in FIG. 7, the driver IC provided facing the LED array is
Indicated by

FIG. 5 shows L after the grooved wiring board 18 on which the LED array 15 has been mounted is fixed to the head holder 25.
It is a perspective view showing a schematic structure of an ED print head.

Further, FIG. 6 shows that after the wiring substrate 18 on which the LED array 15 is mounted is fixed on the base 22, Z of FIG.
It is a figure which shows a part of cross section when it cut | disconnects along a Z line.

In the example described here, the LED array 15
Are positioned and arranged at a position corresponding to the middle of two groove portions 20 adjacent to each other, and the convex portion 24 is fitted into the groove portion 20 of the wiring substrate with groove 18 so that the wiring substrate 18 and the head holder are And 25 are fixed.

Next, referring to FIG. 6, the LED array 15
The relationship between the converging angle θ when the LED is driven and the mounting position of the LED array will be described. In the figure, L ₃ is the p diffusion layer 12
From the lowermost end of the light emitting surface to the vertical line of the upper end of the grooved wiring substrate 18, D ₂ is the vertical distance from the lowermost end of the light emitting surface of the p diffusion layer 12 to the upper surface of the grooved wiring substrate 18. Indicates the distance.

In this configuration example, in order to prevent all or part of the light emitted from the p diffusion layer 12 from being shielded by the upper surface of the grooved wiring substrate 18 or reflected by the upper surface, the equation (2) D ₂ The LED array 15 is arranged on the grooved wiring board 18 so that the distance L ₃ satisfies ≧ L ₃ × tan θ (0 ≦ θ ≦ 90 °) (2).

Next, referring to FIG. 7, the LED of the present invention
An outline of the overall structure of the print head will be described. Figure 7
FIG. 4 is a sectional view showing an example of a schematic structure of an LED print head.

In this configuration, the LED print head is L
The ED array 15, the wiring substrate 18 on which the driver IC 26 is mounted, and the head holder 2 in which the warp of the wiring substrate 18 is suppressed by fitting the protrusions 24 into the grooves provided in the wiring substrate 18.
5, the head holder 25 is fixed to the top of the vertical wall of the base body 22 having an L-shaped cross section, and the rear side of the wiring board 18 is pressed toward the base body 22 side to press the wiring board 18 onto the base body 22. Fixing member 30 having L-shaped cross section
And a focusing rod lens array 32 and a cover 34. In addition, the 1st fixing member 30 is also called a 1st supporting member here. The LED array 15 is provided on the grooved wiring board 18 as described with reference to FIGS. 5 and 6, and the driver IC 26 is provided on the wiring board 18 behind the LED array 15.
It is equipped with. LED array 15 and driver IC 26
And are electrically connected by a wire bond 28. The grooved wiring board 18 on which the LED array 17 and the driver IC 26 are mounted is fixed and attached to the head holder 25. This attachment is shown in FIGS. 3, 5 and 6
The procedure is similar to that already described with reference to.

On the other hand, the groove 20 is formed by using the first supporting member 30.
The end of the substrate 18 on the side opposite to the side is pressed against the base body 22 side and fixed. Further, in this configuration example, the converging rod lens array 32 is provided on the base body 22 so as to be separated from the substrate 18. Further, a cover 34 is provided so as to face the base body 22. This cover 34 fixes the converging rod lens array 32, and also has an edge emitting type LE.
The light is emitted from D and does not pass through the rod lens array 32, so that the light is blocked from irradiating the photosensitive drum. Further, the first support member 30 and the cover 34 are fixed to the end face of the vertical wall of the mace body 22 by the cover 34 so as to press the first support member 30 against the end face by the common screw 35, so that the first support member 30 and the cover 34 are fixed. The other end of the member 30 presses and fixes the end of the wiring board 18 on the side opposite to the LED array 15 side.

Next, using the LED print head, LE is used.
A method for forming an image of light emitted from the D array on the photosensitive drum will be described with reference to FIG.

In the above-mentioned configuration example, the central axis of the converging rod lens 32 is aligned with the emission axis direction of the p diffusion layer 12 of the LED array 15, and the light collection angle (θ) emitted from the etching end face of the p diffusion layer 12 is set. The emitted light of (1) is imaged on the photosensitive drum 36 via the focusing rod lens array 32 to form a latent image.

As can be understood from the above description, according to the LED print head of this example, the LED array 1
5 and the driver IC 26 are mounted on the grooved wiring board 18 via a thermosetting resin or an insulating resin, and then the grooved wiring board 18 on which the components are mounted is mounted on the groove portion 20 of the board 18 and the convex portion of the base body 22. By fitting with the part 24,
Since the warp of the substrate 18 on the light emitting side of the LED array is corrected to be a flat surface, all the light emitting dots of the LED array 15 arranged in the line direction can be turned on in a straight line.

Further, in this configuration example, the LED array 15
Of the step, the end face of the grooved wiring board 18, and the convex portion 24 provided on the base body 22 form the converging angle θ of the imaging optical system.
Since it is arranged at such a height and position that it does not overlap, it is possible to prevent the generation of unnecessary spots such as a decrease in emission intensity due to light shielding and blurring of the emission spot due to reflection.

Next, with reference to FIGS. 8, 9 and 10, a method of fixing the substrate and the head holder of the second configuration example will be described.

FIG. 8 is a plan view for explaining a method for manufacturing a grooved wiring board used in the second configuration example. still,
The diagonal lines in FIG. 8 do not represent the cross section, but are diagonal lines added to clearly explain the cutout portion.

Generally, when the grooved wiring board 46 is formed by notching, the board cutting portion 45 is cut out from the base material 44 using an end mill or the like. Therefore, the working distance of the end mill becomes the shortest in the case where the base material 44 does not have the cutout portion and only the outer shape of the substrate 46 is cut out. On the other hand, when the number of notches increases, the working distance of the end mill becomes longer and the board cost increases. Further, conventionally, when the substrate cutout portion 45 is cut out from the base material 44 by an end mill, a reference hole is formed in the wiring base material using a drill or the like,
A wiring pattern is formed by photolithography etching using the reference hole as a reference point, and finally, an outer shape to be a wiring board is cut out from the base material using an end mill. For this reason, the dimensional accuracy of the notch and the wiring pattern is limited to ± 0.1 mm because the processing accuracy of all the above-described steps is accumulated.

On the other hand, in the second configuration example, the groove portion 48 (here, a round hole) for the grooved wiring board 46 is formed by using a drill or the like when forming the reference hole before forming the wiring pattern. After that, only the cutout portion 45 of the substrate is cut out from the base material 44 along the cutout line 49 using an end mill. By performing such processing, the working distance of the end mill can be shortened as compared with the conventional one. Further, since the round hole 48 can be formed with high precision by a drill, the accuracy of the distance between the cutout portion, here the round hole, and the wiring pattern is improved as compared with the conventional case.

In the second configuration example, the processing accuracy of the hole and the electrode pattern can be made smaller than ± 0.1 mm.
It is possible to form a substrate with high accuracy and low cost.

Next, referring to FIG. 9, the wiring board 4 with grooves is formed.
A method of fixing 6 to the base body 40 will be described.

In the second configuration example, as in the case of the first embodiment, an epoxy resin or a bismaleside triazine resin (also referred to as BT) is used as the grooved wiring board 46.
And a member made of glass cloth or resin and porous ceramics. Therefore, the grooved wiring board 46
Has relatively high flatness, but as described above, when a plurality of LED arrays 15 and driver ICs 26 for driving are actually mounted, when components are fixed to the substrate 46, a thermosetting resin used for fixing is used. Stress is applied to the grooved wiring board 46, and the grooved wiring board 46 is warped.

In the second configuration example, the LED array side substrate 4 is used.
An arc-shaped groove portion 48 is provided in the end face portion of 6 in the direction of the LED array. The groove 48 is also referred to as a round hole here.

On the other hand, the base body 4 is made to correspond to the round hole 48.
A round pin 42 having a diameter slightly larger than the diameter of the round hole 48 is provided on the upper surface of 0 so as to face the round hole 48. By fitting the round hole 48 of the grooved wiring board 46 into the round pin 42 of the base body 40, the board end surface portion on the LED array side can be fixed to the base body 40 so as to be flat.

Further, in the second configuration example, the end face portion of the grooved wiring board 46 on the side opposite to the LED array mounting side is fixed by using the first supporting member 30 (FIG. 10). Since this fixing method has already been described in the first configuration example, detailed description thereof will be omitted.

Next, referring to FIGS. 11 and 12, the third
A method of fixing the substrate and the head holder in the configuration example will be described. 11 is a perspective view for explaining the fixing method, and FIG. 12 is a sectional view for explaining the structure of the LED print head.

First, the round hole 48 of the substrate 46 is fitted into the round pin 42 of the head holder 43. After that, the second support member 38 is used to press and fix the support member 38 in the a direction. At this time, the screw 37 is used as a method of fixing the second support member 38. Further, a converging lens array 32 is mounted on the base body 40 on the light emitting side of the LED array so as to be separated from the LED array. Further, in order to fix the converging lens array 32, an L-shaped cover 34 is used facing the base body 40. In this way, the grooved wiring board 46 is moved by the second support member 38 in the direction of the arrow (a).
Since the substrate 46 and the base body 40 are fixed while being restrained in the direction), the substrate 46 and the base body 40 can be firmly fixed.

The operation principle of forming the latent image by forming the light emitted from the LED print head on the photosensitive drum is the same as that of FIG. 7 described above, and therefore detailed description thereof will be omitted here.

Next, with reference to FIGS. 13 and 14, a method of fixing the substrate and the head holder of the fourth configuration example will be described. 13 is a perspective view for explaining the fixing method, and FIG. 14 is a sectional view for explaining the structure of the LED print head.

The fourth configuration example is different from the first, second and third configuration examples in that an L-shaped third plate is used as a fixing plate for fixing the end face portion of the substrate opposite to the light emitting side of the LED array. The point is that the support member 50 is used. The other configurations of the wiring board with groove 46, the base body 40, the focusing lens array 32, and the cover 34 are the same as those of the first, second, and third configuration examples, and thus detailed description thereof is omitted here.

In the third configuration example, the L-shaped third support member 5 is used.
Since 0 is used, it is possible to suppress the substrate 46 from the a direction and the b direction with respect to the substrate 46.
The substrate 46 can be fixed to the base body 40 more firmly than in the third configuration example.

As can be understood from the above description, in the second, third and fourth configuration examples, light is emitted from the p diffusion layer of the LED array by applying a voltage between the P and N electrodes of the LED array. The light emission axis is aligned with the central axis of the focusing lens array. Further, the focusing lens array is adjusted so that the etching end face of the p diffusion layer and the surface of the photosensitive drum are in focus. By performing such adjustment, the light emitted from the LED array can be imaged on the photosensitive drum to form a latent image. Further, the light collection angle θ to the converging lens array is because the etching bottom end face of the LED array, the end face of the grooved wiring board and the round pin of the base body are all located outside the light collection angle.
There is no generation of unnecessary spots such as a decrease in emission intensity due to light shielding and blurring of the emission spot due to reflection. Also, LE
Since the groove is fitted to the round pin of the base body on the board end surface on the D array mounting side, the warp of the grooved wiring board surface is corrected and all the light emitting dots of the LED array arranged in the line direction are aligned on a straight line. Can be turned on.

In the above-described configuration example, the shape of the groove portion of the grooved wiring board and the convex portion of the head holder is formed in the shape of a quadrangle and the shape of an arc, but it may be a triangle, a trapezoid or a polygon. .

[0056]

As is apparent from the above, according to the present invention, a plurality of groove portions are provided on the light emitting end face side of the grooved wiring substrate, and on the other hand, a head holder having a convex portion at a position facing the groove portions. Since the groove is provided, the warpage of the grooved wiring board can be corrected by fitting the groove and the protrusion. Therefore, the light emitting dots of the LED array can be turned on in a straight line. In addition, with respect to the incident light from the edge emitting LEDs to the converging rod lens array, the substrate is in a non-blocking and non-reflecting state (not to irradiate the end face of the LED array, the light emitting side end face of the substrate and the convex portion of the head holder). Since the groove portion is fitted to the convex portion of the head holder, the reduction of the light emission efficiency due to the light shielding of the auxiliary member as in the conventional case is reduced, and the blurring of the light emission spot due to reflection and the generation of unnecessary spots are eliminated.

[Brief description of drawings]

1 (A) and 1 (B) are end-face emitting LEs of the present invention.
It is a top view and a side view of a D array.

FIG. 2 is a sectional view of an edge emitting LED array of the present invention.

FIG. 3 is a perspective view for explaining a method of fixing the grooved wiring board and the head holder.

4A to 4B are cross-sectional views after fixing the wiring board with groove and the base body.

FIG. 5 is a perspective view for explaining the structure of the LED print head of the present invention.

FIG. 6 is a cross-sectional view for explaining the structure of the LED print head of the first configuration example.

FIG. 7 is a cross-sectional view for explaining the overall configuration of the LED print head of the first configuration example.

FIG. 8 is a plan view of a base material for explaining a method for producing a grooved wiring board.

FIG. 9 is a perspective view provided for explaining a method of fixing the LED print head of the second configuration example.

FIG. 10 is a cross-sectional view provided for explaining the overall configuration of the LED print head of the second configuration example.

FIG. 11 is a perspective view provided for explaining a fixing method of the LED print head of the third configuration example.

FIG. 12 is a cross-sectional view provided for explaining the overall configuration of the LED print head of the third configuration example.

FIG. 13 is a perspective view provided for explaining a fixing method of the LED print head of the fourth configuration example.

FIG. 14 is a cross-sectional view provided for explaining the overall configuration of the LED print head of the fourth configuration example.

[Explanation of symbols]

 10: n layer base material 11: diffusion prevention film 12: p diffusion layer 13: insulating layer 14: p electrode 15: LED array 16: n electrode 18: wiring board with groove 20: groove portion 22: base body 24: convex portion 25 : Head Holder 26: Driver IC 28: Wire Bond 30: First Support Member 32: Focusing Rod Lens Array 34: Cover 35: Screw 36: Photosensitive Drum 38: Second Support Member 50: Third Support Member

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takaatsu Shimizu 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Kazuo Tokura 1-12-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (6)

[Claims] 1. A plurality of edge-emitting LED arrays, and the L
In an LED print head comprising a wiring board on which an ED array is mounted and a converging rod lens array for collecting light emitted from the LED array, the wiring board is a light emitting end surface of the edge emitting LED array. A wiring board with a groove having a plurality of grooves on the side, and further, a convex portion that is fitted to the groove portion in a non-blocking and non-reflecting state with respect to incident light from each of the edge emitting LED arrays to the converging rod lens. An LED print head comprising a head holder formed. 2. The LED printhead according to claim 1, wherein the protrusions are fitted to each other with the width of the protrusions being wider than the width of the grooves. 3. The LED printhead according to claim 1, wherein the groove portion has a width L greater than a groove width on a substrate surface on the LED mounting side.
An LED print head, characterized in that it is provided so that the groove width on the substrate surface on the ED non-mounting side becomes narrow. 4. The LED print head according to claim 1, wherein the convex portion of the head holder is provided so that a hem width thereof is narrower than a tip width of the convex portion. 5. The LED printhead according to claim 1, wherein the non-light emitting side end face of the grooved wiring board is fixed,
An LED print head, wherein the head holder is provided with a fixing member. 6. The LED printhead according to claim 1, further comprising a cover facing the head holder to fix the converging rod lens array.