JP2002019177A - Optical printer head - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a device with high accuracy and lower cost. SOLUTION: The optical printer head 120 of the present invention includes a light emitting element array 111 in which a plurality of light emitting elements 101 are arranged. The light emitting element 101 is a functional block 10
2 is formed. The functional block 102 includes the base 10
0 is disposed in the recess 102a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical printer head.

[0002]

2. Description of the Related Art One of optical writing systems widely used in electrophotographic printers is an LED system. This LED method uses a fine LED (light emitting).
LED; LEDs formed by arranging light-emitting diodes (LEDs) in an array at the pitch corresponding to the print density and the printer width.
An optical printer head including an array is used as a light source of an optical writing system.

An optical printer head including an LED array is generally formed by the following steps. First, a plurality of light emitting diodes are formed on a semiconductor substrate, a chip including a predetermined number of these light emitting diodes is cut out by dicing or the like, and then the chip is mechanically mounted on an elongated base, so that a light including an LED array is formed. A printer head is obtained.

On the other hand, when an optical printer head is used in a printer device, all the LED arrays constituting the optical printer head need to be formed at a prescribed pitch in order to perform printing without unevenness or omission. However, in the above process, each chip is mechanically attached to the base by a mounting device. For this reason, it is difficult to accurately arrange the chip at a desired position, and in particular, the pitch of the LED array may be disturbed at the joint of the chips, thereby deteriorating the print quality.

In recent years, as one of mounting methods for electronic devices, a mounting method using a FSA (Fluidic Self-Assembly) method has been developed. According to the FSA method, an electronic device having a size and a predetermined shape of 10 to several hundred microns (hereinafter, referred to as a “functional device”) is dispersed in a liquid, and holes or holes having substantially the same size and shape as the functional device are formed. This is a technique in which the functional device is mounted on the base by pouring the liquid into the surface of the base including the fitting part and fitting the functional device into the hole or the fitting part. Regarding the FSA method, for example, information display magazine (S. Drobac. INFORMATION)
DISPLAY VOL. 11 (1999) 12-1
6), US Pat. No. 5,545,291, US Pat. No. 5,783,856, US Pat.
24,186, and U.S. Pat.
No. 545, etc.

Next, an example of a mounting process of a semiconductor device using the FSA method will be briefly described.

(1) First, a wafer made of single crystal silicon and containing hundreds to millions of electronic devices is divided into thousands to millions of functional blocks by etching.
The functional blocks obtained by the division have a predetermined three-dimensional shape, and each has a predetermined function. The electronic device may have a simple structure such as a transistor, or may have a complicated structure such as an IC.

(2) In addition to the above-described functional blocks, a base in which these functional blocks are fitted is formed. Holes for fitting the functional blocks are formed in the base by stamping, etching, laser, or the like. This hole is formed so as to match the size and shape of the functional block.

(3) Next, the functional blocks formed by the above-described steps are dispersed in a liquid, and the dispersion is caused to flow over the surface of the substrate formed in the step (2). By this step, the functional blocks pass through the surface of the base and fall into holes provided in the base to fit in a self-aligning manner. The functional blocks that did not fit into the holes are recovered from the dispersion liquid, cleaned, re-dispersed in the same cleaned liquid, and flowed to another new substrate surface. While the above steps are repeated, the functional block and the dispersion continue to be reused.

(4) The functional block fitted in the hole formed in the base is electrically wired by a general metallizing method or the like,
Functions as part of the final electrical circuit. Through the above steps, the functional block is mounted on the semiconductor device.

According to the FSA method, a large number of functional blocks can be mounted on the base at a time, so that the price of a device such as a display can be reduced and the production speed can be improved. In addition, since mounting can be performed using only non-defective products that can be driven in advance by inspection as functional blocks, the reliability of the device can be improved.

In addition, various materials such as glass, plastic, and silicon can be used for the base for fitting the functional block, and the degree of freedom in selecting the material used for the base is high. Similarly, the material used for the functional block can be selected according to the function required for the functional block, such as silicon, germanium-silicon, gallium-arsenic, and indium-phosphorus. As described above, the FSA method is expected to have excellent functions and effects as one of the electronic device mounting methods.

[0013]

If a functional block manufactured by using the FSA method is applied to an optical device such as the above-described optical printer head, a highly accurate and low-cost device can be obtained. It is considered possible.

An object of the present invention is to provide a high-precision and low-cost optical printer head.

[0015]

An optical printer head according to the present invention is an optical printer head including a light emitting element array formed by arranging a plurality of light emitting elements, wherein the light emitting elements are formed in functional blocks. The functional block is disposed in a concave portion provided in the base and includes at least one light emitting element.

The functional block is disposed in a recess provided in the base by using the FSA method described above. When the FSA method is used, the functional blocks can be precisely arranged at desired positions on the substrate, so that it is possible to obtain an optical printer head including a light-emitting element array with less disturbance in pitch and high accuracy. When this optical printer head is used in a printer device, print quality can be improved.

Preferred embodiments of the optical printer head include (1) to (4).

(1) The functional block can include a semiconductor device.

(2) A plurality of the functional blocks can be arranged.

(3) The functional blocks can be arranged substantially parallel to one axis.

In this case, the functional blocks can be arranged in series. In this case, the functional blocks can be arranged in two or more rows.

Alternatively, the functional blocks can be arranged in a staggered pattern.

(4) The planar shape of the functional block is 1
It is desirable to have symmetry of rotational symmetry or double rotational symmetry. Here, the symmetry of the two-fold rotational symmetry refers to a property that, when rotated 180 ° around the center of gravity, matches the shape before rotation. In addition, the term “one-time rotational symmetry” refers to a property having no rotational symmetry. According to this configuration, the light emitting elements formed in the functional block can be aligned in a certain direction.

(5) Further, it is desirable to include an optical member for condensing light emitted from the light emitting element, if necessary.

(6) The light emitting elements can be arranged in a staggered lattice.

The light emitting element is a light emitting diode,
It is desirable to use a surface-emitting type semiconductor laser diode and any one of an organic EL element and an inorganic EL element.

(7) A driver IC for driving the light emitting element can be formed on the base.

In this case, the functional block including the driver IC can be arranged in a recess provided in the base. Further, in this case, it is desirable that the functional block including the driver IC has a different shape and size from the functional block including the light emitting element.

In addition, it is preferable that a wiring for electrically connecting the driver IC and the light emitting element is formed on a surface of the base.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] (Structure of Device) FIG. 1 is a perspective view schematically showing an optical printer head 120 according to a first embodiment of the present invention. FIG. 2 is a sectional view of the optical printer head 120 shown in FIG. FIG. 3 shows the optical printer head 1 shown in FIG.
20, the light emitting element 101 and the driver IC 10
FIG. 3 is a plan view schematically showing functional blocks 102 and 104 each including No. 3;

The optical printer head 120 is applied to a printer device (not shown). As shown in FIG. 1, the light output surface 100a faces the photosensitive drum 200 installed in the printer device. Installed in here,
The light emitting surface 100a is the light emitting element 1
01 is the surface on the side where it is installed.

The optical printer head 120 includes a light emitting element array 111 (see FIG. 3) described later. The light emitting element array 111 is formed by arranging a plurality of light emitting elements 101. Each light emitting element 101 is installed such that a light emission port is located on the light emission surface 100 a of the base 100. Therefore, each light emitting element 101 emits light from an emission port arranged on the emission surface 100a.

Each of the light emitting elements 101 constituting the light emitting element array 111 is formed in a functional block 102 as shown in FIG. The functional block 102 including the light emitting element 101 is provided with the concave portion 1 provided on the surface of the base 100.
02a.

The base 100 is made of a material such as silicon, glass and plastic. The material of the base 100 is appropriately selected according to the type of the functional element and the functional block 102, the use of the optical printer head 120, and the like.

The functional block 102 is formed by being fitted into the concave portion 102a of the base 100 by the FSA method described above in the section of the background art. The functional block 102 includes a semiconductor device depending on, for example, the type of the light emitting element.

FIG. 1 shows an example in which the function block 102 has a truncated quadrangular pyramid shape. However, the shape of the functional block 102 is not limited to this, and may be various shapes depending on the application and function. For example, the planar shape of the functional block 102 has a two-fold rotational symmetry such as a rectangle, a parallelogram, an ellipse, or the like, or a one-time rotational symmetry such as a trapezoid, in addition to a square or a circle. It may be shaped.

As described above, each of the light emitting elements 101 constituting the light emitting element array 111 has a function block 1
02 is formed. FIG. 3 illustrates a case where one light-emitting element 101 is formed in one functional block 102. That is, in the light emitting element array 111, the same number of the light emitting elements 101 as the number of the functional blocks 102 are arranged.

In FIG. 3, the functional blocks 102 including the light emitting elements 101 are arranged in a row in parallel with the X-axis direction. According to this configuration, since the light emitting points are arranged in a line, it is not necessary to adjust the timing of the image data for each light emitting element 101, so that data processing can be simplified. In addition,
The method of arranging the functional blocks 102 is not limited to this. For example, as shown in a light-emitting element array 121 shown in FIG. It can also be arranged in. Further, in FIG. 4, the functional blocks 102 are arranged in a staggered lattice. According to the light emitting element array 121 shown in FIG. 4, the number of elements per unit area can be increased by making the pitch smaller than that of the light emitting element array 111 shown in FIG. Higher density can be achieved.

The light emitting element 101 is provided on the emission surface 1 of the base 100.
It has a function of emitting light in a direction substantially perpendicular to 00a (Y-axis direction shown in FIG. 1). As the light emitting element 101, for example, a VCSEL (vertical cavity surface emitting)
laser; surface emitting semiconductor laser diode), LED,
Organic or inorganic EL devices (electroluminescent devic
e) etc. can be used.

An optical member 110 is formed on the light emitting element 101. The optical member 110 has a function of condensing light emitted from the light emitting element 101 and emitting the light to the surface of the photosensitive drum 200. As the optical member 110, for example, a transparent member having a convex lens shape as shown in FIG. 2 can be used. Note that, in FIG.
Is omitted.

In this embodiment, the case where the optical printer head 120 includes the optical member 110 has been described, but the emission angle of the light emitted from the light emitting element 101 is small.
The optical member 110 need not be used as long as the light emitted from the light emitting element 101 can be efficiently incident on a predetermined position of the photosensitive drum 200 without using the optical member 110.

As shown in FIGS. 2 and 3, a driver IC 103 is formed on the base 100. The driver IC 103 is installed to drive the light emitting element 101.

As shown in FIG. 3, the driver IC 103 is formed in the functional block 104 similarly to the light emitting element 101. The functional block 104 is arranged in a concave portion 104a provided in the base 100. Like the functional block 102, the functional block 104 is formed by being fitted into the concave portion 104a of the base 100 by the FSA method described above in the section of the background art.

The function block 104 including the driver IC 103 is replaced with the function block 10 including the light emitting element 101.
2 has a different shape and size. Therefore,
The recesses 102a and 104a are
It has a shape and size suitable for 2,104. That is, the concave portion 102a and the concave portion 104a of the base 100 have different shapes and sizes. Recess 102a and Recess 1
04a has a different shape and size, so that the functional blocks 102 and 104
In the step of fitting the functional blocks 102 and 104 into the concave portions 102a and 104a,
04a can be selectively fitted. In this case, it is desirable to first fit the larger functional block into the corresponding recess.

The driver IC 103 and the light emitting element 10
1 is formed on the surface of the base 100. A driver IC 103 and a light emitting element 101 are formed in functional blocks 102 and 104, respectively.
0 are fitted in the recesses 102a, 104a provided on the base 100, respectively.
a) is flat. Therefore, the wiring layer 105 connecting the driver IC 103 and the light emitting element 101 can be formed by a general metallization method. Since the method of forming the wiring layer by the metallization method is simpler than the method of forming the wiring by wire bonding, in the optical printer head 120 of the present embodiment, the functional block including the driver IC 103 and the light emitting element 101 Recesses 102 and 104 provided in the base 100
The wiring layers can be formed more easily because they are fitted into the a and 104a, respectively. As a result, a lower cost optical printer head 120 can be obtained. In FIG. 2, the electrodes of the functional blocks 102 and 104 are not shown.

In FIG. 3, the driver IC 10
3 is provided on one side of the light emitting element array 111, and in FIG.
21, the driver IC 103,
The arrangement position of 113 is not limited to the positions shown in FIGS. 3 and 4 and can be appropriately selected. Similarly, a wiring pattern for electrically connecting the driver IC 103 and the light emitting element 101 (see FIG. 3) and a wiring pattern for electrically connecting the driver IC 113 and the light emitting element 101 (see FIG. 4) are also shown in FIG. 3, the pattern is not limited to the pattern shown in FIG. 4 and can be appropriately selected.

According to the optical printer head 120 of the present embodiment, each light emitting element 101 is formed in the functional block 102, and the functional block 102 is fitted into the concave portion 102 a provided in the base 100 by using the FSA method. Thereby, the light emitting element array 111 is formed. This FS
When the method A is used, the functional block 102 can be accurately arranged at a desired position, so that it is possible to obtain an optical printer head including a light-emitting element array with little disturbance of pitch and high accuracy. When this optical printer head is used in a printer device, print quality can be improved.

(Operation of Device) The operation of the optical printer head 120 according to the present embodiment will be described below by taking as an example a case where the optical printer head 120 is applied to a printer including the photosensitive drum 200 shown in FIG.

When each light emitting element 101 constituting the light emitting element array 111 is driven in the optical printer head 120, light is emitted based on an image signal. Each light emitting element 10
The light emitted from the optical member 1 spreads at a predetermined radiation angle,
It is incident on 10. After the light is collected by the optical member 110, the light is emitted to the photosensitive drum 200.

The operation of the optical printer head 120 in the above embodiment is an example, and various changes can be made without departing from the spirit of the present invention.

(Modification of Light-Emitting Element Array) In the present embodiment, the structure illustrated in FIGS. 5 to 8 can be adopted instead of the light-emitting element array 111 shown in FIG. FIG.
FIG. 8 to FIG. 8 are plan views showing only the light emitting element array portion. In each of the drawings, description of a wiring layer for electrically connecting the driver IC and the light emitting element is omitted.

(1) FIG. 5 is a plan view schematically showing the light emitting element array 211. Light emitting element array 2 shown in FIG.
11, the functional block 2 including the light emitting element 201
3 are similar to the light emitting element array 111 shown in FIG. 3 in that the light emitting elements are arranged in a line in the X-axis direction. However, a plurality of light emitting elements 201 (two light emitting elements in FIG. FIG. 3 in that
Is different from the light emitting element array 111 shown in FIG. Further, in the light emitting element array 211, the light emitting elements 201 are arranged in a staggered lattice.

In this case, the planar shape of the functional block 202 is a shape having two-fold rotational symmetry such as a rectangle, a parallelogram, or an ellipse, or a shape having one rotational symmetry such as a trapezoid. It is desirable. FIG. 5 shows a case where the planar shape of the functional block 202 is a rectangle.
According to this configuration, the light emitting elements 201 formed in the functional block 202 can be aligned in a certain direction.

(2) FIG. 6 is a plan view schematically showing the light emitting element array 311. Light emitting element array 3 shown in FIG.
11 is a case where the functional block 302 including the light emitting element 301 is X
A point in which the light emitting elements 301 are arranged in a staggered lattice, a point that the planar shape of the functional block 302 is rectangular, and one functional block 3
The light emitting element array 211 is similar to the light emitting element array 211 shown in FIG. On the other hand, the planar shape of the functional block 202 is better than that of the functional block 3.
It has a shape closer to a square than the planar shape of No. 02. Further, the light emitting element 201 included in one functional block 202
Is two, whereas the number of light emitting elements 301 included in one functional block 302 is six. In these respects, the light emitting element array 311
Different from 1.

The number of light emitting elements included in one functional block can be appropriately selected depending on the shape and size of the functional block.

(3) FIG. 7 is a plan view schematically showing the light emitting element array 411. The light emitting element array 411 shown in FIG. 6 has the same configuration as the light emitting element array 3 shown in FIG. 6 except that the planar shape of the functional block 402 including the light emitting element 401 is a parallelogram.
It has almost the same configuration as 11.

Each of the functional blocks 402 constituting the light emitting element array 411 has its center of gravity in a planar shape arranged in a line in the X-axis direction. Further, as shown in FIG.
The light emitting element 401 is in a direction crossing the X axis (the direction of arrow A).
Can be arranged. Note that the arrangement direction of the light emitting elements 401 is not limited to the direction of the arrow A, and can be appropriately selected.

(4) FIG. 8 is a plan view schematically showing the light emitting element array 511. The light-emitting element array 511 is formed by arranging the functional blocks 302 shown in FIG. 6 in a staggered pattern. That is, like the light emitting element array 511, not only the light emitting elements 301 can be formed in a staggered lattice, but also the functional blocks 302 themselves can be formed in a staggered lattice.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing an optical printer head according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view schematically showing the optical printer head shown in FIG.

FIG. 3 is a plan view schematically showing functional blocks each including a light emitting element and a driver IC in the optical printer head shown in FIG.

FIG. 4 is a plan view schematically showing a modified example of a functional block including a light emitting element and a driver IC in the optical printer head shown in FIG. 1;

FIG. 5 is a plan view schematically showing a modified example of a functional block including a light emitting element in the optical printer head shown in FIG.

FIG. 6 is a plan view schematically showing a modified example of a functional block including a light emitting element in the optical printer head shown in FIG.

FIG. 7 is a plan view schematically showing a modified example of a functional block including a light emitting element in the optical printer head shown in FIG.

FIG. 8 is a plan view schematically showing a modified example of a functional block including a light emitting element in the optical printer head shown in FIG.

[Explanation of symbols]

100 Base 100a Emission surface 101, 201, 301, 401 Light emitting element 102, 202, 302, 402 Functional block 102a, 104a Depression 103, 113 Driver IC 104, 114 Functional block 105, 115 Wiring layer 110 Optical member 111, 121, 211 , 311,411,511 emitting element array 120 optical printer head 200 photosensitive drum _{d 1, d 2, d 3} , d 4, d 5, d 6 pitches

Claims (17)

[Claims] 1. An optical printer head including a light emitting element array formed by arranging a plurality of light emitting elements, wherein the light emitting element is formed in a functional block, and the functional block is formed in a concave portion provided in a base. An optical printer head, wherein the optical printer head includes at least one light emitting element. 2. The optical printer head according to claim 1, wherein the functional block includes a semiconductor device. 3. The optical printer head according to claim 1, wherein a plurality of the functional blocks are arranged. 4. The optical printer head according to claim 3, wherein the functional blocks are arranged substantially parallel to one axis. 5. The optical printer head according to claim 4, wherein the functional blocks are arranged in series. 6. The optical printer head according to claim 3, wherein the functional blocks are arranged in two or more rows. 7. The optical printer head according to claim 6, wherein the functional blocks are arranged in a staggered pattern. 8. The functional block according to claim 1, wherein the planar shape of the functional block is one-time rotationally symmetric or two-dimensional.
An optical printer head having rotational symmetry. 9. The optical printer head according to claim 1, further comprising an optical member for condensing light emitted from the light emitting element. 10. The optical printer head according to claim 1, wherein the light-emitting elements are arranged in a staggered pattern. 11. The optical printer head according to claim 1, wherein the light emitting element is a light emitting diode. 12. The optical printer head according to claim 1, wherein the light-emitting element is a surface-emitting type semiconductor laser diode. 13. The optical printer head according to claim 1, wherein the light emitting element is an organic EL element or an inorganic EL element. 14. The optical printer head according to claim 1, wherein a driver IC for driving the light emitting element is formed on the base. 15. The driver IC according to claim 14, wherein the driver IC is formed in a functional block different from the functional block including the light emitting element, and the functional block including the driver IC is disposed in a recess provided in a base. Is an optical printer head. 16. The optical printer head according to claim 15, wherein the functional block including the driver IC has a different shape and size from the functional block including the light emitting element. 17. The optical printer head according to claim 14, wherein a wiring for electrically connecting the driver IC and the light emitting element is formed on a surface of the base.