JPH06143685A - Image apparatus - Google Patents

Abstract

PURPOSE:To position a lens array and an image array of an image apparatus correctly and moreover simultaneously with the electric connection of a substrate to a base plate. CONSTITUTION:Clip terminals 10 are tightly secured to a base plate 2. A substrate 12 with an image array is positioned to the base plate 2 by catching elements 4 and the clip terminals 10 of the base plate 2. The positioning of the substrate is carried out approximately simultaneously with the electric connection thereof to the base plate. An end face of the substrate is positioned by providing a reference face 8 in the base plate 2 perpendicularly to the substrate 12. Further, a lens holder is set and positioned by the upper surface of the substrate 12. The side face of the holder is positioned by the side face of the base plate 2.

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 print head, a contact image sensor and a liquid crystal shutter array head.

[0002]

2. Description of the Related Art In an image device such as an LED head, a liquid crystal shutter array head, and a contact image sensor, a substrate on which an image array is mounted is fixed to a base plate with an adhesive or the like. However, it is difficult to control the thickness of the adhesive, and the height position of the substrate varies, resulting in deterioration of image quality. Further, the substrate has a warp, and it is difficult to eliminate the warp of the substrate with an adhesive. The mounting accuracy of the board is mainly studied in the height direction, and the mounting accuracy in the lateral direction of the board, that is, the positioning of the end face in the longitudinal direction of the board is hardly studied. And when the mounting accuracy in the horizontal direction of the board decreases,
The focusing performance between the lens array and the image array is degraded, and the image quality is degraded. Another issue is the electrical connection to the substrate. The connection method used conventionally uses a flexible printed circuit board, but the flexible printed circuit board is expensive and it is difficult to control soldering to electrodes provided on the circuit board. Therefore, in order to obtain a high-quality image device at a low price, it is possible to bond the substrate to the base plate without using an adhesive, and at the same time, the problem of the warp of the substrate, the problem of positioning the end face of the substrate, and the electrical connection to the substrate. Need to solve the problem.

As a related prior art, it is known that the base plate of the image device and the lens holder of the lens array are provided separately and separately (see, for example, Japanese Patent Application Laid-Open No. 2-273258). There is a prior application by the inventors of the present invention to press the surface of the substrate with a sandwiching piece provided on the base plate and solder the clip terminal to the electrode provided on the substrate for connection (Japanese Patent Application No. 3-34185).
No. 7). However, this prior application does not consider integrating the clip terminal with the base plate, nor does it consider positioning of the end face of the substrate.

[0004]

It is an object of the invention of claim 1 to (1) fix a substrate on which an image array is mounted to a base plate without using an adhesive, correct the warp of the substrate, and position the end face of the substrate. The problem of the invention of claim 2 is
In addition to the above, (2) the positioning and electrical connection of the board can be performed almost simultaneously, and (3) the board on which the accessory circuit of the image device is mounted and the board on which the image array is mounted,
It is to be able to connect easily. The object of the invention of claim 3 is, in addition to the object of claim 1, (4) the height position and the side surface position of the lens holder,
It is to enable accurate positioning.

[0005]

The image device according to the present invention comprises a base plate having a sandwiching piece and an alignment member at the end of the upper surface,
A substrate on which the image array is mounted, and by pressing the end portion of the substrate between the upper surface of the base plate and the sandwiching piece while the end surface of the substrate on which the image array is mounted is in contact with the alignment member. The substrate on which is mounted is fixed to the upper surface of the base plate.
Preferably, the board on which the accessory circuit of the image device is mounted is arranged on the lower surface of the base plate, and the board of the accessory circuit and the board on which the image array is mounted are connected via a clip terminal. Further preferably, by separating the lens holder from the base plate, the reference surface provided on the lower surface of the lens holder is brought into contact with the upper surface of the substrate on which the image array is mounted, and the side surface of the lens holder is brought into contact with the side surface of the base plate. , The lens array and the image array are aligned.

As the image device, the LED shown in the embodiment is used.
In addition to the head, a liquid crystal shutter array head, a contact type image sensor or the like may be used as long as it uses an image array and a lens array.

[0007]

According to the present invention, the end portion of the substrate on which the image array is mounted is press-fitted and fixed between the upper surface of the base plate and the sandwiching piece. In addition, the end surface of the substrate is brought into contact with a positioning member provided on the base plate for positioning. As a result, the board can be easily fixed and aligned,
Moreover, the lower surface of the substrate is in close contact with the base plate to correct the warp.

According to the second aspect of the present invention, the substrate of the auxiliary circuit of the image device is mounted on the lower surface of the base plate, and the clip terminal is connected to the substrate on which the image array is mounted. As a result, the two substrates can be easily connected, and after the substrates on which the image array is mounted are press-fitted, they can be easily electrically connected by, for example, soldering. Further, the board on which the image array is mounted is pressed and fixed from both sides by the sandwiching piece and the clip terminal, and the warp is further eliminated.

According to the third aspect of the present invention, the lens holder and the base plate are separately provided, and the reference surface provided on the lens holder is brought into contact with the upper surface of the substrate on which the image array is mounted so that the height of the lens holder is increased on the upper surface of the substrate. Position. Similarly, the side surface of the lens holder is brought into contact with the side surface of the base plate, and the side surface of the lens holder is positioned by the side surface of the base plate. In this way, the height position of the lens array is positioned at the height position of the upper surface of the substrate, which has the closest relationship with the height position of the image array,
The side surface position of the lens array is determined by positioning the end surface of the substrate with respect to the base plate and the side surface of the lens holder with respect to the side surface of the base plate.

[0010]

EXAMPLE FIGS. 1 to 7 show an example of an LED head. In FIG. 1, reference numeral 2 is a base plate, and is made of engineering plastic such as polyphenylene sulfide or polycarbonate, which is inexpensive and has high rigidity and heat resistance and processing accuracy. 4 is a sandwiching piece, 6 is a protrusion, and 8
Is a reference surface with the surface being exposed. The reference plane 8 of the protrusion 6 is used for alignment. The base plate 2 has a simple shape and can be easily molded including the sandwiching piece 4, the protrusion 6 and the like. Reference numeral 10 is a clip terminal, which is integrally formed with the base plate 2, for example. Instead of integral molding, a hole for inserting the clip terminal 10 may be provided in the base plate 2 for molding, and the clip terminal 10 may be attached to the molded base plate 2 and fixed with an adhesive or the like.

Reference numeral 12 is a glass substrate, 13 is a soldering portion, and the clip terminal 10 and the substrate electrode provided on the glass substrate 12 are soldered, 14 is an LED array, and 16 is a drive I.
It is C.

FIG. 2 shows the positioning and electrical connection of the glass substrate 12 with respect to the base plate 2. In the figure, 20 is a plastic substrate and 22 is a drive IC. On the lower surface of the base plate 2, the sandwiching pieces 5 and the protrusions 7 similar to those on the glass substrate 12 side are provided. Since the positioning of the plastic substrate 20 is not important, it is not necessary to provide the protrusion 7 with a reference surface.

As shown in FIG. 3, the glass substrate 12 is cut by a diamond cutter 24 or the like. The diamond cutter 24 cuts from the top of the substrate 12 (the side on which the LED array 14 is mounted), the direct cutting surface does not reach the bottom of the substrate 12, and the bottom of the substrate is later broken. Therefore, the cutting accuracy of the upper portion of the substrate 12 is high, but the cutting accuracy of the bottom portion is low. Therefore, only the upper portion of the right end face of the substrate 12 is set to the reference plane 8
To improve the mounting accuracy.

The glass substrate 12 is mounted on the base plate 2, and is pressed downward in FIG. 2 by the sandwiching piece 4 near the end face thereof. The sandwiching piece 4 is formed on the glass substrate 1 during molding.
Mold so that 2 can be pressed. At the same time, the upper part of the right end surface of the glass substrate 12 in the figure is brought into contact with the reference surface 8. As a result, the right end surface of the glass substrate 12 is positioned with respect to the base plate 2. Here, the reason why the entire right end surface of the glass substrate 12 is not brought into contact with the reference surface 8 is to improve the positioning accuracy of the end surface.

At the same time as the glass substrate 12, the plastic substrate 20 is set on the base plate 2. Substrates 12, 20
Is pressed by the spring property of the clip terminal 10 to be temporarily fixed, and is brought into close contact with the base plate 2. Clip terminal 10
After setting, the cream solder is applied with a dispenser or the like, and soldering is performed with, for example, a hot air heater. Soldering with a hot-air heater can locally heat in a short time, so that the glass substrate 12 and the LED array 14 are not overheated. Further, since no soldering iron or the like is used, no pressure is applied to the substrate electrode and the substrate electrode is not peeled off.

In this way, the glass substrate 12 is pressed from both sides by the sandwiching piece 4 and the clip terminal 10 and comes into close contact with the base plate 2. Therefore, no adhesive is needed, and the warp of the glass substrate 12 is eliminated. Further, if the boards 12 and 20 are set and then soldered, the boards 12 and 20 can be electrically connected. Glass substrate 12
Since the right end face of the LED array 14 is positioned by the reference plane 8 and is positioned by using the upper part of the end face having high cutting accuracy, the lateral position of the LED array 14 with respect to the base plate 2 can be accurately positioned.

4 and 5 show the sandwiching piece 4 and the reference surface 8. FIG. 4 is a view of the base plate 2 as seen from the lateral direction, in which the projection 6 is made thicker than the sandwiching piece 4 and the reference surface 8 is provided. Further, FIG. 5 is a view of the base plate 2 seen from above, and the tip of the sandwiching piece 4 is brought out in front of the reference surface 8 so that the surface of the glass substrate 12 can be pressed.

6 and 7 show the completed LED head. In FIG. 6, reference numeral 30 denotes a lens holder which is made conductive by mixing conductive particles such as carbon powder or metal powder with an engineering plastic such as polyphenylene sulfide or polycarbonate.
Reference numeral 32 is a lens array, for example, a self-focusing lens array is used, and 34 and 34 are protrusions, which position the bottom of the lens array 32 with the lens array bottom reference surface 36. Further, 38 is a frame which surrounds and positions the lens array 32 on four sides. Reference numeral 40 denotes a protrusion, which is provided at two positions, such as the left and right ends and the center of the glass substrate 12, and is in contact with the upper surface of the glass substrate 12 to position the height of the bottom portion of the lens holder 30. Reference numeral 42 is a lens holder bottom reference surface provided on the bottom of the protrusion 40. The side portion 44 of the lens holder 30 is brought into contact with the side surface of the base plate 2, and the side surface of the lens holder 30 is positioned with respect to the side surface of the base plate 2. The contact surface is shown as 46, and the side surface of the base plate 2 and the side surface of the lens holder 30 are faced on both sides to obtain accuracy. 48 is a metal bottom plate, LED
In addition to preventing toner from entering the head, it also serves as an electrostatic shield. The bottom plate 48 is fixed to the lens holder 30 with the screw 50 shown in FIG. 7, and the reference surface 42 provided on the protrusion 40 of the lens holder 30 is brought into close contact with the upper surface of the glass substrate 12. FIG. 7 shows the positional relationship by disassembling the image device.

The performance of the LED head of the embodiment will be described.
The flatness of the surface of the base plate 2 can be manufactured with an accuracy of about ± 20 μm, and the flatness of the surface of the glass substrate 12 is ± 10.
It can be manufactured with an accuracy of about μm. The glass substrate 12 is fixed to the base plate 2 without using an adhesive. Therefore, there is no error due to variations in the thickness of the adhesive. Then, the glass substrate 12 is pressed against the base plate 2 by the sandwiching piece 4 and the clip terminal 10, and the warp is eliminated. As a result, the glass substrate 1 with respect to the base plate 2
The mounting accuracy of No. 2 is about ± 10 μm. The LED array 14 can be mounted on the glass substrate 12 with an accuracy of about ± 10 μm. The total of these errors is ± 5
The error is 0 μm or less.

The lens holder 30 is positioned by the upper surface of the glass substrate 12 using the reference surface 42. The positioning error here is about ± 10 μm, and the height error of the LED array 14 with respect to the protrusion 40 of the lens holder 30 is ± 20 μm (± 10 μm + LED with respect to the substrate 12).
(± 10 μm of array 14) or less. Therefore, the lens holder 30 is positioned with respect to the LED array 14 with extremely high accuracy. The mounting accuracy of the LED array 14 based on the base plate 2 is ± 50 μm or less, and the surface flatness of the linear array of the LED array 14 is extremely high. Therefore, the lens array 32 and the LED array 1
4 and 4 can be accurately positioned in the height direction.

The mounting accuracy of the lens array 32 on the lens holder 30 is determined by the reference surfaces 36, 36. The mounting accuracy is, for example, about ± 20 μm. As a result, the mounting accuracy in the height direction is about ± 80 μm at maximum.

Next, the LED array 14 is replaced by the lens array 32.
On the other hand, if it shifts in the horizontal direction in FIG. 6, the focusing performance deteriorates. However, the upper part of the right end surface of the glass substrate 12 is positioned by the reference surface 8. Positioning is performed at the upper part of the end face with high cutting precision, and the lower part of the end face with low cutting precision is not used for positioning. Therefore, the mounting accuracy in the lateral direction is also significantly improved.

In addition to this, there is a problem of variation in height of the lens array 32. The focusing performance of the lens array 32 is
The center of the lens array 32 in the height direction and the LED array 14
Determined by the distance from the surface. There are various variations in the height of the lens array 32. Therefore, preferably, the lens array 32 is selected according to its height, and a spacer is inserted between the reference surface 36 and the bottom surface of the lens array 32 so as to correct the height variation. If the error in the distance from the center of the lens array 32 in the height direction to the surface of the LED array 14 is ± 100 μm or less, this distance is set between the surface of the photosensitive drum (not shown) and the center of the lens array 32 in the height direction. A high focusing performance can be obtained if the distance is matched with. For this purpose, the variation Δ in the width of the lens array 32 in the height direction may be measured, and the mounting interval between the LED head and the photosensitive drum (not shown) may be corrected by Δ. When the distance between the surface of the LED array 14 and the center of the lens array 32 in the height direction is H, the distance between the center of the lens array 32 and the surface of the photosensitive drum (not shown) must also be H. When the thickness of the lens array 32 is decreased by Δ, the distance between the LED array 14 and the center of the lens array 32 in the height direction is decreased by Δ / 2. Is H + Δ / 2. LED
If the mounting distance between the head and the photosensitive drum is shortened by Δ, high focusing performance can be obtained without adjusting the position of the lens array 32 in the height direction by the spacer.

Since the clip terminal 10 is used to connect the glass substrate 12 and the plastic substrate 20, an expensive flexible printed board becomes unnecessary. The clip terminal 10 has a spring property and can be temporarily fixed at the same time when the substrates 12 and 20 are set, and positioning and soldering are easy. The LED array 14 and the driving ICs 16 and 22 are shielded by a conductive lens holder 30 containing carbon powder or metal powder,
A metallic bottom plate 48 is used to prevent an electric field from a charger or the like and prevent destruction of the LED array 14 or the like. At the same time, with the lens holder 30 and the bottom plate 48, the LED
The inside of the head is sealed to prevent the ingress of toner and paper dust. Furthermore, since the base plate 2 is provided separately from the lens holder 30, molding is easy.

[0025]

According to the invention of claim 1, (1) the substrate on which the image array is mounted is bonded to the base plate without an adhesive, the warp of the substrate is corrected, and the end face of the substrate is positioned to improve the focus performance. In the invention of claim 2,
(2) Positioning of the board and electrical connection are performed almost at the same time to simplify assembly and improve positioning accuracy.
(3) No need for flexible printed circuit board for connection, (4)
A substrate on which an accessory circuit of an image device is mounted and a substrate on which an image array is mounted can be easily and almost simultaneously connected. According to the invention of claim 3, (5) the height position and the side surface position of the lens holder are accurately positioned to improve the image quality.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of an image device according to an embodiment.

FIG. 2 is a cross-sectional view of the main part of the image device according to the embodiment.

FIG. 3 is a cross-sectional view showing a step of cutting a substrate in an example.

FIG. 4 is a front view of a main part of a base plate used in an example.

FIG. 5 is a plan view of a main part of a base plate used in an example.

FIG. 6 is a sectional view of the image device according to the embodiment.

FIG. 7 is a perspective view of essential parts showing an exploded state of the image device according to the embodiment.

[Explanation of symbols]

 2 base plate 4 sandwiching piece 5 sandwiching piece 6 protrusion 7 protrusion 8 reference surface 10 clip terminal 12 glass substrate 13 soldering portion 14 LED array 16 drive IC 20 plastic substrate 22 drive IC 24 diamond cutter 30 lens holder 32 lens array 34 protrusion 36 lens Array bottom reference surface 38 Frame 40 Protrusion 42 Lens holder bottom reference surface 44 Side portion 46 Contact surface 48 Bottom plate 50 Screw

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication H01L 27/14 33/00 N 7376-4M H04N 1/028 Z 8721-5C 1/036 A 8721- 5C B 8721-5C

Claims (3)

[Claims] 1. A base plate having a sandwiching piece and an alignment member at an end of an upper surface thereof, and a substrate on which an image array is mounted, wherein an end face of the substrate on which the image array is mounted is brought into contact with the alignment member. An image device characterized in that the substrate on which the image array is mounted is fixed to the upper surface of the base plate by press-fitting the edge portion of the substrate between the upper surface of the base plate and the sandwiching piece in this state. 2. The substrate of the auxiliary circuit is arranged on the lower surface of the base plate, and the substrate of the auxiliary circuit and the substrate on which the image array is mounted are connected via a clip terminal. Image device. 3. A lens holder on which a lens array is mounted, a reference surface provided on a lower surface of the lens holder is brought into contact with an upper surface of a substrate on which the image array is mounted, and a side surface of the lens holder contacts a side surface of a base plate. The image apparatus according to claim 1, wherein the lens array and the image array are aligned by bringing them into contact with each other.