JPH07186444A - Imaging device - Google Patents

Abstract

PURPOSE:To improve the image forming performance of an imaging device by a method wherein the center of an LED array coincides with that of lens. CONSTITUTION:The pads (6-1)-(6-64) of an LED array 2 is arranged symmetrical about both the X-axis and Y-axis so as to detect the center of the LED array by taking advantage that the positions of electrodes 8 and 8 become parallel to each other only at the center of the array. Further, a marker is provided on a lens holder so as to center a lens.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image device such as an LED head, an image sensor and an EL head.

[0002]

2. Description of the Related Art An image device in which an image array such as an LED array and a monocular lens have a 1: 1 correspondence has been noted for a long time, but has not yet been put into practical use. This is because the center of the image array and the center of the monocular lens must match exactly, so if the centers of both do not match, the output images will overlap at the boundary between the lens and black streaks will occur,
On the contrary, the image is separated into two and a gap is generated, and a white streak occurs. In order to solve these problems, the center of the lens and the center of the image array must be aligned with an accuracy of, for example, about ± 5 μm.

However, it is extremely difficult to exactly align the center of the lens with the center of the image array. For image arrays, it is the outline of the array that is visible, not the center of the array. Then, the outer shape of the array and the center of the array have an error corresponding to the error of the saw when cutting from the wafer.

As another problem, as the resolution of the image device is improved, the density of the pads on the array is increased, which makes bonding difficult. For example, at a resolution of 600 DPI or more, the arrangement pitch of the light receiving and emitting bodies is reduced to 42.5 μm or less, and if the bonding pads are arranged at such a high density, bonding becomes difficult.

[0005]

An object of the present invention is to: 1) enable easy detection of the center of the image array and accurately position the center of the image array; and 2) bond pad in the image array. To increase the area and facilitate bonding. According to the invention of claim 2, in addition to these, 3) the center of the lens and the center of the image array are made to coincide with each other to improve the imaging performance.

[0006]

According to the present invention, a plurality of rectangular image arrays in which a large number of light receiving and emitting bodies are arranged in a line are linearly mounted on a substrate, and a plurality of lenses are linearly arranged on a lens holder. An image device including a lens member, wherein the substrate and the lens member are provided side by side with each image array and each lens corresponding to each other, and the image array is connected to each light receiving and emitting body on its surface. An electrode having a bonding pad is attached to an end thereof, and the pad is arranged symmetrically with respect to two axes of the long side direction central axis and the short side direction central axis of the array. Preferably, the lens holder is provided with a marker for indicating the center position of each lens.

[0007]

According to the present invention, the bonding pads of the image array are made symmetrical with respect to the two axes of the long side direction and the short side direction of the array. With this arrangement, the electrodes are aligned in the direction from the pad to the light receiving / receiving body on both sides of the center of the array, and the directions of the electrodes are opposite at other positions, which makes it possible to detect the center of the array. Next, the pad area is increased due to the biaxial symmetry of the pad, which facilitates bonding.

According to the second aspect of the invention, a marker is provided on the lens holder so that the center of the lens can be positioned. If the center of the lens can be positioned and the center of the image array can be positioned, the center of the lens and the image array can be aligned, and a monocular lens type image device excellent in image forming performance can be obtained.

[0009]

EXAMPLE An example is shown in FIGS. LED first
The structure and substrate of the array 2 will be described. 1 and 2 LED
Array 2 is shown. In addition, instead of the LED array 2, EL
An array or a photovoltaic array may be used. Reference numeral 4 is a light-emitting body, 64 are linearly arranged on the central axis (XX axis) of the LED array 2, 6 is a pad for wire bonding or flip chip bonding, and 8 is each light emission. The light-emitting body 4 and the pad 6 are connected by the electrode of the body 4. There are 64 pads 6, 32 of which are arranged on the lower side in the figure of the row of light emitters 4 and the remaining 32 are arranged on the upper side of the row of light emitters 4. The pads 6-1 to 6-64 are arranged symmetrically with respect to the two axes X-X and Y-Y of the LED array 2. Note that here, the symmetry with respect to the two axes means that the electrode 8 is ignored and the pad 6 is symmetric with respect to the two axes. 1
0 is a center marker provided on the substrate, which is the LED array 2
The common electrode pattern on the bottom surface of the
It is for determining the center position of. The center marker 10 may not be provided.

By arranging the pads 6-1 to 6-64 symmetrically about the X and Y axes, the area of each pad 6 can be increased. This will be described with reference to FIG. Assuming that the width along the long side direction of the pad 6 is A, the upper limit of the width A is the luminous body 4.
It is determined by the arrangement pitch C of the two. The width A can be made larger than the arrangement pitch of the light emitters 4, for example, can be equal to or larger than the width B obtained by adding the width of one light emitter 4 to the arrangement pitch of the light emitters 4, and the width A of the pad 6 can be B and C. It becomes an intermediate value of. For example 40
The width A of the pad 6 is 100 μm for the 0 DPI array.
The width A is 70 for a 600 DPI array.
It can be about μm.

Since the pads 6-1 to 6-64 are biaxially symmetric, the connection relationship with the light emitter 4 changes with the central Y axis as a boundary. For example, in the lower pads 6-1 to 6-32, the left half pads 6-1 to 6-16 are connected to odd-numbered light emitters, and the right half pads 6-17 to 6-32 are even-numbered light emitters. Connected to a light emitter. Similarly, the upper pads 6-33 to 6
At −64, the left half pads 6-33 to 6-48 are connected to the even-numbered light emitters, and the right half pads 6-49 to 6 are provided.
-64 is connected to the odd-numbered light emitters. In addition, subscripts such as -1 to -64 in this specification refer to the light emitter 4 and the pad 6.
Represents a number such as.

The connection relationship between the pad 6 and the light emitter 4 is that the sum of the dot numbers of the light emitters connected to the two pads symmetrical about the Y axis is 65. For example pad 6-
1 is connected to the light emitter 4-1 and is symmetrical with the pad 6-
32 is connected to the light emitter 4-64, and the sum of the numbers of the light emitters becomes 65. Similarly, pads 6-33 at both ends in the upper row
And the pad 6-64 are connected to the light emitter 4-2 and the light emitter 4-63, and the sum of the light emitter numbers is again 65. Arranging the pads 6 symmetrically about the Y-axis facilitates connection with the individual electrode wiring on the substrate.

Next, by arranging the pads 6 symmetrically with respect to the X and Y axes of the LED array 2, it becomes easy to determine the center of the array 2. This point will be explained with reference to FIG. 2. The electrodes 8, 8 on both sides have opposite directions at positions other than the center of the array, but the electrodes 8, 8 on both sides are arranged only at the center of the array.
The directions of 8 become equal. For example, in FIG. 2, both electrodes 8, 8 face downward only on both sides of the center of the array.

FIG. 3 shows the connection relationship between the pads 6-1 to 6-64 and the pads 12 and 14 on the substrate side. Pad 6-
1 to 6-64 are wire-bonded to the pads 12 and 14 on the substrate side, and 12-1 to 12-64 are substrate pads for connecting to the lower pads 6-1 to 6-32 of the array 2. . 14-1 to 14-64 are the upper pads 6-3
It is a board side pad for connecting to 3 to 6-64. 1
6 is a marker provided on the substrate-side pads 12 and 14 for indexing the center of the array 2. Marker 16 is Y
Arranged symmetrically with respect to the axis, the markers 16 are moved to the innermost side on both sides of the Y axis, and are moved to the outermost sides at both ends of the array 2. Therefore, the center of the array 2 can be obtained from the direction of the marker 16. The pads 12 and 14 may be arranged in a staggered manner in two stages, and in that case, if a marker 16 is provided on the pads 12 and 14 near the center of the array 2, the pads are arranged in two stages so that the centers are It will be easier to find.

Reference numeral 18 denotes a through hole, which is a board-side pad 1
It is for connecting the wirings connected to the wirings 2 and 14 to the back surface wirings of the substrate. Reference numeral 20 denotes a common electrode wiring for connecting to the common electrode on the back surface of the array 2 via a common electrode pattern (not shown). Reference numerals 32 and 34 denote individual electrode wirings provided on the substrate, which collectively refer to the substrate-side pads 12, 14 and the wirings and through holes 18 connected thereto. In the figure, only the lower individual electrode wiring 32 is shown, and the upper individual electrode wiring 34 is omitted.

FIG. 4 shows one substrate 12 of the array 2 on the substrate side, and the common electrode pattern 22. The common electrode pattern 22 faces the bottom surface of the array 2 and is connected to the common electrode of the array 2, and center markers 10, 10 for defining the Y axis of the array 2 are provided at the center. Pattern 22
The common electrode wiring 20 is taken out from the left end or the right end.

FIG. 5 shows the front and back of the substrate 30. In the embodiment, since the wiring density is reduced by using the individual electrode wirings 32 and 34, the substrate 30 may be an inexpensive hard printed board such as a glass-epoxy board, and the wiring 3
2, 34 and the like may be wirings obtained by etching copper foil, and thin film wirings having poor productivity are unnecessary. For example, 40 LED arrays 2 are arranged linearly, and corresponding to this, individual electrode wiring 3
20 sets of 2 and 34 are provided. This is because the two individual electrode wirings 32 and 34 form one set in the array 2. Backside wiring 42, 42 is provided on the backside of the substrate 30,
Individual electrode wiring 32, 3 divided into two pieces of the ED array 2
4 through the row 40 of through holes and the backside wiring 42,
Connect to each other. The row 40 of through holes is formed by arranging the above through holes 18 in two rows and obliquely. This is because the through holes 18 require a large area, and the two rows and the diagonal arrangement prevent the area of the substrate 30 from increasing.

Reference numerals 44 and 44 denote drive ICs for dynamically driving the LED array 2 one array at a time. The signal is sent to the back surface wiring 42 through the row 40 of through holes, and again through the row 40 of through holes. , To the individual electrode wirings 32 and 34. The dynamic drive of the array 2 is performed by a signal from the common electrode wiring 20, and the arrays 2 are turned on one by one from the common electrode pattern 22 through the common electrode. Further, the driving IC 44 reverses the order of signals for each array, and when driving the array on the left side of FIG. 3, for example, sends the signal of the first dot (signal to the light emitter 4-1) to the pad 12-1. 1 when driving the right array 2.
The dot signal is sent to the pad 12-33. As a result,
The signals to the light-emitting bodies having the same dot number are sent to pads that are symmetrical with respect to the central axes of the individual electrode wirings 32 and 34 for each array.

The operation of the LED array 2 and the substrate 30 will be described. In the LED array 2, the pads 6-1 to 6-64 are two.
Since the pads 6 are arranged symmetrically with respect to the axis, the area of the pad 6 can be increased. Therefore, even with an array having a resolution of 600 DPI, for example, the width A of the pad 6 can be set to about 70 μm, which facilitates bonding. On the other hand, in the array which is asymmetric with respect to the X axis, the upper limit of the width of the pads 6 is the arrangement pitch of the light emitters 4, and the width becomes 40 μm or less at 600 DPI, for example, which makes bonding difficult.

By arranging the pads 6-1 to 6-64 symmetrically with respect to the Y axis of the array 2, the connection with the individual electrode wirings 32 and 34 becomes easy. For example, when driving the array 2 on the left side of FIG. 3, the signal to the first light emitter 4-1 appears on pad 12-1, and the signal to the last light emitter 4-64 is pad 12-3.
Appears in 2. On the other hand, when driving the array 2 on the right side,
The signal to the first emitter appears on pads 12-33 and the signal to the last emitter appears on pads 12-64. Here, the pad 6-1 of the left array is connected to the pad 12-1, the pad 6-32 is connected to the pad 12-32, and the pad 6-1 of the right array is connected to the pad 12-33 and the pad 6-32.
Is connected to the pads 12-64, the pads on the array 2 and the pads 12 and 14 of the individual electrode wirings 32 and 34 can be correctly connected. On the other hand, if an array that is point-symmetric with respect to the center is used, the individual electrode wirings 32 and 34 intersect and the wiring does not become a low-density wiring.

The substrate 30 may be a low-density substrate such as a hard printed circuit board because the individual electrode wirings 32 and 34 are arranged above and below the row of the LED array 2 and the wiring density is reduced to 1/2. . Since both ends of the individual electrode wirings 32 and 34 are divided by the board-side pads 12 and 14, respectively,
The columns 40 of through holes and the rear surface wiring 42 are connected to each other. Moreover, in a rigid printed circuit board, it is easy to form the through-hole row 40.

[0022]

[Positioning of monocular lens and LED array] Figs. 6 and 7
The positioning of the monocular lens 50 and the LED array 2 is shown in FIG. Reference numeral 50 is a monocular lens, which is arranged one-to-one with the LED array 2, and 52 is four markers provided on the lens holder 54, which are markers that indicate the center of the lens 50. The lens holder 54 is arranged so as to face the substrate 30, and the monocular lens 50 is mounted on the lens holder 54.

The LED array 2 is symmetrical with respect to the two axes of the X axis and the Y axis, and the directions of the electrodes 8 are parallel on both sides of the center of the array 2, so that the center of the array 2 is detected. LE
The center of the D array 2 is the center marker 10 of the substrate 30.
Mounted on the board, or the marker 1 on the substrate 30
Position with 6 and mount. When aligning the LED array 2 with the image recognition device, the marker 16 can be seen regardless of which part of the wiring is put in the field of view, and from this, the direction of the center can be known. For example, in the case of FIG. 4, the center direction is indicated by the marker 16 regardless of which pad first enters the visual field, and the center marker 10 or the like can be easily searched. As a result, the wiring pattern on the substrate 30 and the LED
The center of array 2 coincides.

In mounting the monocular lens 50, after the lens holder 54 is set to face the substrate 30, the marker 52 is set.
The lens 50 is mounted using. At this time, the marker 52 is detected by the image recognition device, and the lens 50 is mounted so that the center thereof coincides with the centers of the four markers 52. When the lens 50 is mounted, the inspection is performed, and it is confirmed that the centers of the four markers 52 (center of the lens 50) and the centers of the center marker 10 and the LED array 2 are the same. If these centers are aligned, the image viewed from the monocular lens 50 shows that the left and right upper and lower four ends of the array 2 and the pads 1 at the upper and lower ends are arranged.
2-1, 12-34, 14-1, 14-34 should be included.

If the centers do not match, either end is missing from the image or the image is distorted. Image distortion is lens 5
Although it is also caused by the distortion of 0 itself, if the center of the lens 50 coincides with the center of the array 2 or the center markers 10 and 10, the distortion is vertically and horizontally symmetric, and otherwise it is asymmetric. Therefore, the position of the lens 50 is readjusted so that the four edges on the left, right, top, and bottom of the array 2 and both ends of the pads 12 and 14 are all included in the image viewed from the monocular lens 50, and the distortion of the image is symmetric vertically and horizontally. To do. In this way, the center of the lens 50 and L
The center of the ED array 2 and the center of the substrate wiring near the array 2 are made to coincide with each other.

[0026]

According to the invention of claim 1, 1) the center of the image array can be easily detected, the positional accuracy of the center of the image array is improved, and 2) the area of the bonding pad of the image array is increased to perform bonding. Can be easy. Claim 2
In addition to these, in the invention of 3), 3) the center of the lens can be aligned with the center of the image array.

[Brief description of drawings]

FIG. 1 is a plan view showing a surface pattern of an LED array in an image device according to an embodiment.

FIG. 2 is an enlarged plan view of an essential part of FIG.

FIG. 3 is a plan view showing a connection relationship between an LED array and individual electrode wirings in the image device of the embodiment.

FIG. 4 is a plan view showing a main wiring portion on the board side in the image device of the embodiment.

FIG. 5 is a diagram showing a state of front and back surfaces of a substrate of the image device according to the embodiment.

FIG. 6 is a diagram showing the positioning of the lens in the embodiment.

FIG. 7 is a perspective view showing the positional relationship between the substrate and the lens holder in the example.

[Explanation of symbols]

 2 LED array 4 Light emitter 6 Pad 8 Electrode 10 Center marker 12, 14 Substrate side pad 16 Marker 18 Through hole 20 Common electrode wiring 22 Common electrode pattern 30 Substrate 32, 34 Individual electrode wiring 36, 38 Substrate side pad row 40 Through Rows of holes 42, 42 Backside wiring 44 Drive IC 50 Monocular lens 52 Marker 54 Lens holder

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01L 33/00 NM H04N 1/024

Claims (2)

[Claims] 1. A substrate on which a plurality of rectangular image arrays in each of which a large number of light receiving and emitting bodies are arranged in a line are linearly mounted, and a lens member in which a plurality of lenses are linearly arranged on a lens holder. In the image device, wherein the substrate and the lens member are provided side by side with each image array and each lens corresponding to each other, the image array is connected to each light receiving and emitting body on its surface,
An image device, wherein an electrode having a bonding pad is attached to an end portion, and the pad is arranged symmetrically with respect to two axes of a long side direction central axis and a short side direction central axis of the array. . 2. The image device according to claim 1, wherein the lens holder is provided with a marker for indicating a center position of each lens.