JP2849636B2 - Imaging device - Google Patents

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 type image sensor, and a liquid crystal shutter array head.

[0002]

2. Description of the Related Art In image devices 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 fluctuates, resulting in deterioration of image quality. Also, the substrate is warped, and it is difficult to eliminate the warpage of the substrate with an adhesive. The mounting accuracy of the substrate is mainly studied in terms of the mounting accuracy in the height direction, and the mounting accuracy in the horizontal direction of the substrate, that is, the positioning of the end face in the longitudinal direction of the substrate is hardly studied. And when the mounting accuracy of the board in the horizontal direction decreases,
The focus performance between the lens array and the image array is reduced, and the image quality is reduced. Another problem is the electrical connection to the substrate. The connection method used conventionally uses a flexible printed board, but the flexible printed board is expensive, and it is difficult to manage soldering to electrodes provided on the board. Therefore, in order to obtain a low-cost, high-quality image device, the board can be bonded to the base plate without using an adhesive, and the problem of board warpage, the problem of positioning the end face of the board, and the electrical connection to the board are required. Need to solve the problem.

As a related prior art, it is known that a base plate of an image apparatus and a lens holder of a lens array are separated and provided separately (for example, see Japanese Patent Application Laid-Open No. 2-273258). Further, there is a prior application of the inventors of the present invention in which the surface of the substrate is pressed by a sandwiching piece provided on the base plate, and a clip terminal is connected to an electrode provided on the substrate by soldering (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 the positioning of the substrate end surface.

[0004]

The object of the invention of claim 1 is as follows. (1) The image device is configured without the base plate, and the cost of the image device is reduced. In addition, the image quality is prevented from deteriorating due to insufficient surface flatness of the base plate. (2) The first circuit board and the second circuit board are connected without an adhesive, and mechanical connection and electrical connection are simultaneously performed. Accordingly, deterioration of image quality due to uneven thickness of the adhesive or the like is eliminated, and a delay in a process such as waiting for the adhesive to dry is prevented. Further, the disassembly of the image device is facilitated, and repair and repair for a partial defect are facilitated. (3) A flexible printed board is not required for connecting the first circuit board and the second circuit board, and the cost is reduced. (4) The horizontal position and the vertical position of the image array can be accurately positioned, and the focus performance of the image device is improved. (5) Eliminate the warpage of the image array substrate caused by bringing the first circuit board and the second circuit board into close contact with the clip terminals. (6) It is to further enhance the adhesion between the two substrates and to complete the connection of the two substrates before assembling to the housing, thereby facilitating the assembling. (7) An object of the present invention is to improve the adhesion performance of the substrate of the image array to the reference plane in the vertical direction of the housing and further increase the positioning accuracy of the array in the vertical direction.

[0005]

A first circuit board on which an image array is mounted;
A second circuit board on which the drive circuit is mounted is fixed with clip terminals in a state where the back surfaces are aligned, and
The electrodes of the first and second circuit boards are electrically connected to each other, and the first and second circuit boards are placed in a housing in which a lens array is mounted on an upper part. An image device arranged so as to be located on an array side, wherein a vertical reference surface for positioning a main surface of the first circuit board and an end surface of the first circuit board are positioned on an inner wall of the housing. A horizontal reference surface is provided, and a position corresponding to the vertical reference surface of the second circuit board main surface is determined in a state where the main surface and the end surface of the first circuit board are in contact with the two reference surfaces. The first circuit board and the second circuit board are housed at predetermined positions in the housing by being pressed toward the first circuit board by a pressing piece provided at the bottom of the housing.

Preferably, the housing is provided with a lens array reference surface, and the housing is mounted while positioning the bottom surface of the lens array on the reference surface. Preferably, the housing includes a first piece parallel to the first circuit board, a second piece branched at a substantially right angle from the first piece and abutting a side of the lens array, and a substantially right angle from the first piece. A second piece and a third piece extending in the opposite direction, wherein the first piece is provided with the vertical reference surface, and the third piece is provided with the horizontal reference surface.

As an image device, the LED shown in the embodiment is used.
In addition to the head, a liquid crystal shutter array head, a contact image sensor, or the like is used, and preferably, an image array and a lens array are used.

[0008]

The operation of the first embodiment will be described. According to the present invention, the first circuit board and the second circuit board are brought into close contact with each other. For this purpose, clip terminals are used, and the substrates are brought into close contact with each other by the spring force of the clip terminals. In addition, since the clip terminals are used, the connection between the substrates and the electrical connection can be performed simultaneously. The use of the clip terminals eliminates the need for a flexible printed board and an adhesive. Eliminating the need for the adhesive means that thickness control and the like become unnecessary, and also means that it is not necessary to stop the process until the adhesive is dried and solidified. Further, when a defect is found, it becomes easy to remove the clip terminal and replace or repair the defective board.

When the two substrates are brought into close contact with the clip terminals, a base plate becomes unnecessary. As a result, the shape of the housing is simplified and the cost is reduced, and the focusing performance is not reduced due to the lack of flatness of the surface of the base plate. Next, in the present invention, a vertical reference plane and a horizontal reference plane are provided on the housing to position the image array substrate, and the vertical position and the horizontal position of the image array are determined. As a result, the focus performance of the image array is improved whether in the vertical or horizontal direction. The role of the vertical reference plane is not limited to this. If the two substrates are brought into close contact with the clip terminal, the substrate may be warped by the force from the clip. Also, due to the effect of the second circuit board of the array having low smoothness and large thickness variation, distortion or warpage occurs on the main surface of the substrate on which the array is mounted. Here, if the main surface of the array substrate is brought into contact with the vertical reference surface, the warp or deformation of the main surface of the array substrate is corrected on this reference surface.

Further, clip terminals are arranged on both sides of the two substrates, and the two substrates are brought into close contact with each other with only the clip terminals and joined together. For this reason, the connection of the two substrates is completed before being incorporated in the housing, which facilitates the incorporation into the housing. Also, a pressing piece of the drive circuit board is provided in the housing,
The image array substrate is pressed against a vertical reference surface of the housing to enhance contact with the vertical reference surface.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described using an LED head as an example. In FIG. 1, reference numeral 2 denotes a housing, which is made of an engineering plastic such as polyphenylene sulfide or polycarbonate, which is inexpensive and has high rigidity and heat resistance and high processing accuracy. Reference numeral 4 denotes an image array, which is an LED array here. For example, about 40 image arrays 4 are linearly arranged. 6
Is an image array substrate, which uses a glass substrate or a ceramic substrate whose surface is glass-glazed, and uses a flat substrate having a high surface smoothness. Reference numeral 8 denotes a drive circuit for the image array 4, which includes a drive IC and a capacitor, and is mounted on an inexpensive drive circuit board 10 such as plastic. Reference numeral 12 denotes a lens array such as a self-focusing lens array. 1
Reference numeral 4 denotes a metal cover which covers the opening of the housing 2, electrostatically shields the image array 4, the drive circuit 8, and the like, and also prevents toner and paper dust from entering.

Reference numerals 16 and 18 denote clip terminals, which are provided in large numbers along both end surfaces of the substrates 6 and 10, respectively. The clip terminals 16 and 18 press the substrates 6 and 10 by their elasticity to bring them into close contact with each other, and at the same time, solder or the like to the substrates 6 and 10.
To be fixed. In the embodiment, the clip terminal 16 on the right side of FIG. 1 is used for both coupling and electrical connection of the substrate, and the clip terminal 18 on the left side is used only for the close contact of the substrates 6 and 10.
For this reason, the left clip terminal 18 is particularly called a board fixing clip terminal.

The housing 2 basically includes a first piece 20 parallel to the substrate 6, a second piece 22 perpendicular to the first piece 20 and parallel to the side surface of the lens array 12, and a board 6 perpendicular to the first piece 20. ,
10 and a third piece 24 parallel to the end face. The housing 2 further includes a pressing piece 26 for pressing the main surface of the substrate 10 from the opposite side of the image array 4. The fourth piece 28 is positioned so that the right side surface of the lens array 12 is positioned.
Is provided.

Numeral 30 denotes a projection provided on the first piece 20, which is provided with a vertical reference surface at the tip thereof and is positioned in contact with the main surface of the substrate 6.

FIG. 2 shows the arrangement of the clip terminals 16, the projections 30, and the like. The clip terminals 16 are arranged at a pitch of, for example, about 1 mm at a portion having the smallest pitch, and at a pitch of, for example, about 5 mm at other portions. Protrusion 3
The number 0 is, for example, about 10 to about 10, and the number of the substrate fixing clip terminals 18 is also about 10 to about the same as the number of the projections 30. The plastic printed circuit board 10 is
2 is pressed upward from the lower side in FIG. Therefore, the main surface of the substrate 6 made of glass or the like is pressed toward the vertical reference surface provided on the lower surface of the projection 30, and the main surface of the substrate 6 is positioned by the vertical reference surface.

When the substrate 6 made of glass or the like and the printed circuit board 10 are brought into close contact with the clip terminals 16 and 18, if the clip terminals 16 and 18 have too strong spring properties, warpage as shown in FIG. 3 will occur. Further, when the substrate 6 such as glass is closely adhered to the printed substrate 10 having low shape accuracy and large warpage, the substrate 6 such as glass may be warped due to the influence of the printed substrate 10. This situation is shown in FIG. On the other hand, in the embodiment, the main surface of the substrate 6 made of glass or the like is in contact with the vertical reference surface provided at the bottom of the protrusion 30. Then, the substrate 6 is pressed toward the vertical reference plane by the pressing piece 26, and the warpage or deformation of the main surface of the substrate 6 is corrected by the vertical reference plane.

FIG. 4 shows the soldering of the clip terminal 16 and the substrate electrode 40 of the substrate 6. In the figure, reference numeral 42 denotes an insulating film, for example, using a polyimide resin film, and reference numeral 44 denotes a soldering portion using cream solder. Clip terminal 16, 1
8 is set, the insulating film 42 and the clip terminal 1
The cream solder is applied indiscriminately regardless of whether it is on 6, 18 or above. Therefore, the application of the cream solder becomes extremely easy.
Next, when the cream solder is melted by a hot air heater or the like, the cream solder escapes from the unfamiliar insulating film 42 and concentrates on the clip terminals 16 and 18 and the substrate electrode 40. Therefore, soldering can be performed simply by applying cream solder indiscriminately and heating with a hot air heater. The insulating film 42 is for separating the common electrode of the image array 4 from its data bus, and is originally necessary for the substrate 6. Therefore, even if the insulating film 42 is provided, the number of steps does not increase. On the side of the printed circuit board 10, there is no need to provide the insulating film 42 because the affinity between the cream solder and the plastic of the board 10 is poor. The clip terminals 16 and 18 may be set on the printed circuit board 10, cream solder may be applied in the same manner, and soldering may be performed using a hot air heater or the like.

In this manner, the electrical connection between the substrates 6 and 10 and the coupling between the substrates 6 and 10 can be performed almost simultaneously and easily. In addition, since the boards 6 and 10 can be joined before being assembled into the housing 2, the boards 6 and 10 can be easily assembled to the housing 2. Furthermore, an expensive flexible printed circuit board is not required for connecting the substrates 6 and 10, and a base plate does not need to be interposed between the substrates 6 and 10. Along with this, the shape of the housing 2 is simplified, and the focusing performance is not reduced due to lack of smoothness of the surface of the base plate.
Since no adhesive or the like is used for bonding the substrates 6 and 10, there is no need to stop the process while the adhesive is being dried or solidified. Also, if the soldering of the clip terminals 16 and 18 is removed,
The substrates 6 and 10 can be easily separated. Accordingly, repair and replacement of a defective board, repair of an image device, and the like are facilitated.

FIG. 5 shows a state in which the housing 2 is taken out alone. In the figure, reference numeral 50 denotes a hole for guiding light from the image array 4 to the lens array 12. 52 is a vertical reference surface provided on the bottom surface of the projection 30, and 54 is the second piece 2.
4 is a lateral reference plane provided in FIG. The lateral reference surface 54 contacts the upper part of the end face of the substrate 6 and positions the upper part of the end face of the substrate 6. As a result, the horizontal position of the image array 4 with respect to the lens array 12 is determined. The substrate 6 includes the image array 4
Is formed by cutting out from the side on which is disposed with a diamond cutter or the like. For this reason, the shape accuracy of the end face of the substrate 6 is high at the top and low at the bottom. Therefore, the lateral reference surface 54 is brought into contact with the upper part of the end face of the substrate 6 to improve the positioning accuracy.

Considering the problem of warping and deformation of the housing 2 itself, the housing 2 is basically composed of the first piece 20.
And a second piece 22 and a third piece 24 substantially perpendicular thereto.
Consists of Therefore, no matter which side the first piece 20 is deformed, the second piece 22 and the third piece 24 are obstructed, and the deformation is prevented. This is a kind of rib effect.
For example, if the first piece 20 attempts to deform in the upward direction in the figure, the second piece 22 prevents this. The third piece 24 blocks if it is going to deform downward.

The positioning of the lens array 12 and the substrate 6 is concentrated on the first piece 20 except for the lateral reference surface 54. Therefore, the shape accuracy of the first piece 20 may be intensively increased. Of particular concern are two reference planes, a vertical reference plane 52 and a lens array bottom reference plane 56. The vertical reference surface 52 is not provided on the entire back surface of the first piece 20 but is provided only on the bottom of the protrusion 30 to reduce the range in which the reference surface is provided. Along with this, it becomes easy to increase the surface accuracy of the vertical reference surface 52.

FIG. 6 shows a modified housing 62.
The housing 62 is obtained by removing the fourth piece 28 from the housing 2 shown in FIGS. The following points are also apparent from the modified example of FIG. The second piece 22 and the third piece 24 are arranged substantially at right angles to the first piece 20 to prevent the first piece 20 from being deformed or warped by the rib effect. Further, the bottom surface of the substrate 10 made of plastic or the like is pressed by the pressing piece 26, and the main surface of the substrate 6 made of glass or the like is brought into contact with the vertical reference surface 52. This not only positions the main surface of the substrate 6 but also corrects warpage, deformation, and the like that occur in the substrate 6.
Further, the upper end face of the substrate 6 is positioned by the lateral reference plane 54, and the lateral position of the image array 4 with respect to the lens array 12 is determined.

FIG. 7 shows the metal cover 14. The metal cover 14 covers one side surface (the right side surface in the figure), the bottom surface, and both end surfaces of the housing 2 and shields the image array 4 and the drive circuit 8. This protects the image array 4 and the drive circuit 8 from electromagnetic waves caused by charging and development on the photosensitive drum (not shown). In addition, shielding is performed so that electromagnetic waves from the image array 4 and the driving circuit 8 do not leak to the surroundings.
At the same time, the metal cover 14 seals the inside of the housing 2 and protects the image array 4 from paper dust, toner and the like.

FIG. 8 shows a housing 8 of still another modification.
2 is shown. In the figure, reference numeral 84 denotes a pressing piece made of plastic, rubber, or the like, which is used instead of the pressing piece 26 of the housing 2 in the embodiment. In the modification of FIG. 8, the pressing piece 84 is provided separately from the housing, the pressing piece 84 is pressed by the metal cover 14, and the main surface of the substrate 6 is placed on the vertical reference surface 52 at the bottom of the protrusion 30.
Contact. In other respects, it is similar to the housing 2 of FIG.

[0025]

According to the first aspect of the present invention, the following effects can be obtained. (1) The first circuit board and the second circuit board are back-to-back with clip terminals, and the connection between the boards and the electrical connection are simultaneously performed. In addition, a flexible printed circuit board and an adhesive are not required. (2) The shape of the housing is simplified by eliminating the need for the base plate, and at the same time, the focus performance is prevented from deteriorating due to insufficient flatness of the base plate surface. (3) The housing is provided with a vertical reference plane and a horizontal reference plane to determine the vertical position and the horizontal position of the image array, thereby improving the focusing performance. Further, warping and deformation of the main surface of the first circuit board are corrected on the vertical reference plane. (4) The two substrates are tightly joined only by the clip terminals, so that the joining of the substrates is completed before assembling into the housing, thereby facilitating the incorporation into the housing. (5) A pressing piece of the second circuit board is provided on the housing, and the first circuit board is pressed against the vertical reference surface of the housing to strengthen the contact with the vertical reference surface. (6) Since the pressing piece is arranged at a position corresponding to the vertical reference surface, the first and second circuit boards can be securely and firmly held between the vertical reference surface and the pressing piece. First
It is possible to maintain the positional accuracy of the circuit board satisfactorily for a long period of time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view in the short half direction of an image apparatus according to an embodiment.

FIG. 2 is a cross-sectional view of a main part in a longitudinal direction of the image apparatus according to the embodiment.

FIG. 3 is a diagram showing the deflection of the superposed substrates.

FIG. 4 is a diagram showing soldering of a clip terminal to a board in the embodiment.

FIG. 5 is a perspective view of a main part of a housing used in the embodiment.

FIG. 6 is a side view of a modified housing.

FIG. 7 is a perspective view of a main part of the image apparatus according to the embodiment.

FIG. 8 is a cross-sectional view in a short direction of an image device according to a modified example.

[Explanation of symbols]

 2 housing 4 image array 6 image array board (first circuit board) 8 drive circuit 10 drive circuit board (second circuit board) 12 lens array 14 metal cover 16 clip terminal 18 board fixing clip terminal 20 first piece 22 second Piece 24 third piece 26 pressing piece 28 fourth piece 30 protrusion 40 substrate electrode 42 insulating film 44 soldering part 50 hole 52 vertical reference surface 54 horizontal reference surface 56 lens array bottom reference surface 62 housing 82 housing 84 Pressing piece

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01L 33/00 H04N 1/036 A H04N 1/028 1/036 (56) References JP-A-4-138262 (JP, A) JP-A-3-213362 (JP, A) JP-A-1-210361 (JP, A) JP-A-1-292894 (JP, A) JP-A-63-273340 (JP, A) JP-A-3-62846 (JP, U) Japanese Utility Model 1-83552 (JP, U) Japanese Utility Model 62-87453 (JP, U) Japanese Utility Model Utility Model 61-176522 (JP, U) (58) Field surveyed (Int. Cl. ⁶⁾ , DB name) B41J 2/44 B41J 2/45 B41J 2/455

Claims (1)

(57) [Claims] A first circuit board on which an image array is mounted;
A second circuit board on which the drive circuit is mounted is fixed with clip terminals in a state where the back surfaces are aligned, and
The electrodes of the first and second circuit boards are electrically connected to each other, and the first and second circuit boards are placed in a housing in which a lens array is mounted on an upper part. An image device arranged so as to be positioned on an array side, wherein a vertical reference surface for positioning a main surface of the first circuit board and an end surface of the first circuit board are positioned on an inner wall of the housing. In the state where the main surface and the end surface of the first circuit board are in contact with the two reference surfaces,
A position corresponding to the vertical reference surface of the second circuit board main surface is pressed toward the first circuit board by a pressing piece provided at the bottom of the housing, and the first circuit board and the second circuit board are positioned at predetermined positions in the housing. An image device, wherein the image device is housed in a storage device.