JPH04117759U - image head - Google Patents

Abstract

(57) [Summary] [Purpose] To eliminate the need for FPC and to reduce the width of the image head. [Structure] A board 4 on the LED side and a board 20 on the ancillary circuit side are connected by a lead 22, and a pitch changing part 24 is provided in the middle. Lead 22 is soldered etc. It is connected to the terminals of the boards 4 and 20, and the common frame portion of the lead frame is cut after soldering.

Description

[Detailed explanation of the idea]

0001

[Field of application of idea]

This idea is especially useful for image heads such as printer heads and image sensors. The present invention relates to a connection between a board on which an optical element is mounted and a board on which ancillary circuits are mounted.

0002

[Prior art]

The image head uses two substrates, with the light receiving and emitting elements mounted on one substrate and the light receiving and emitting elements mounted on the other substrate. Ancillary circuits are often mounted on the board. Connect these boards using flexible cables. Using a lint board (FPC), attach the light receiving and emitting elements to the FPC by pressure bonding with a rubber roll, etc. Connect to the mounted board (for example, Fig. 6 of JP-A No. 1-301,269, Figure 2 of No. 1-57,762). However, with pressure bonding using rubber rolls, the substrate The problem is that the connection area between the FPC and the FPC occupies a large width, making it impossible to downsize the head. There is. Additionally, FPC is an expensive material and increases the cost of the head. There is also the issue of how to do it.

0003

[Problems to be devised]

The problem with this idea is (1) Eliminates the need to use expensive FPC, and (2) The aim is to reduce the width occupied by the connection between the boards, thereby making the head more compact.

0004

[Structure of the idea]

The image head of this invention has a light receiving and emitting element mounted inside the housing of the image head. In addition to arranging the printed circuit board, ancillary circuits for the light receiving and emitting elements are mounted on the outer surface of this housing. In the image head where the mounted board is placed, each board has a lead connection. In addition to providing multiple terminals, connect the terminals of each board with leads, and In this case, a pitch changing part is provided between the connection parts of both terminals, and the base mounted with the light receiving and emitting elements is The pitch of the leads is varied between the board and the board that carries the ancillary circuits of the light receiving and emitting elements. It is characterized by

[0005] In this idea, two leads are made by cutting the common frame part of the lead frame. Connect the board. To connect the lead to the board, for example, solder to a terminal provided on the board. Use tsuke. As a result, the width occupied by the connection portion between the substrate and the lead can be reduced. The pitch of the terminals on the board is different between the receiving and emitting element side and the ancillary circuit side, and the pitch of the terminals on the ancillary circuit side is different. is usually small. One reason for this is that on the receiving/emitting element side, almost the entire length of the board is This is because the receiving and emitting elements are placed across the board, and the terminals are also placed over almost the entire length of the board. . Another reason for the difference in pitch is the mounting of the image head. with image head Usually, a head mounting member is provided on the side facing the auxiliary circuit. For this reason, the auxiliary circuit side In this respect, the terminal can only be provided in the width excluding the mounting member. This conclusion As a result, it is no longer possible to provide terminals along the entire length of the head on the ancillary circuit side, and the end The pitch of the elements is smaller than that on the receiving/emitting element side. Therefore, in this idea, the lead is A switch change section is provided to allow connection even if the terminal pitches on the receiving/emitting element side and the auxiliary circuit side are different. It can be so. An example will be shown below using an LED printer head as an example. LED If you replace it with a photodiode, it becomes an image sensor.

[0006]

【Example】

In Figure 1, 2 is a base plate, which is used as a housing for the image head. . 4 is a board on which many light emitting diode arrays 6 are mounted in a straight line, and 8 is a shift register. It is part of ancillary circuits such as stars. 10 is for fixing the substrate 4 to the base plate 2. The adhesive 12 is a reference surface provided on the base plate 2, and the bonding part with the substrate 4 is flattened. It has a smooth surface. 14 is a protrusion provided on the base plate 2, which is connected to the substrate 4. The contact surface 16 is surfaced and used as a second reference surface. The second reference surface 16 is not provided. Also good. 18 is a self-focusing lens array. 20 is not shown. This board is equipped with ancillary circuits and is fixed to the opposite side of the base plate 2. 22 is ri The lead is cut from the common frame part of the board frame, and 24 is the pitch change part. Ru.

[0007] FIG. 2 shows details of the lead 22. 26 is a terminal provided on the board 4, which is connected to the ancillary circuit side. A similar terminal is also provided on the substrate 20 of. However, on the ancillary circuit side, the terminal pitch is becomes smaller. 28 is a common frame part of the lead frame, and the lead 22 is connected to the terminal 26. Cut after soldering.

[0008] FIG. 3 shows a cross section of the image head. 30 is the head cover, 32 is the head image. The attachment member 34 to the image device is a screw.

[0009] FIG. 4 shows the bottom of the image head. The board 20 on the side of the auxiliary circuit is the entire length of the head. For example, it is provided with a width between the mounting members 32, 32. Also, lead 22 The connection terminal to the board 20 is also provided in the width between the mounting members 32, 32, and The pitch is different from that on the board 4 side, where terminals 26 are provided along almost the entire length of the board. 36 is the head cap A hole is provided in the bar 30, and 38 is a connector provided in the board 20.

0010 In assembling the image head of the embodiment, adhesive 10 is used to attach the substrate 4 to the head base. It is fixed to the reference plane 12 of No. 2. The substrate 4 used has a uniform thickness and is not warped. Next The image element array 6 is bonded to the substrate 4 with an adhesive (not shown), and the image element array 6 is bonded to the substrate 4 with an adhesive (not shown). Variations in thickness are compensated for by varying the thickness of the adhesive. As a result, the image element The surface of the array 6 is at a constant height with respect to the reference plane 12 of the base plate 2. Variations and warpage in the height of the substrate 4 are corrected using the reference surface 16, and variations and warpage are bonded. Absorb with agent 10. As a result, the surface height of the substrate 4 becomes more uniform. image element By aligning the surface heights of the child arrays 6, the positional accuracy with the center of the lens array 18 is improved. However, the accuracy of focusing on a photosensitive drum (not shown) is improved.

[0011] Terminals 26 for soldering the leads 22 and the like are provided on the substrate 4 and the substrate 20. base On the side of the plate 4, the terminals 26 are arranged at relatively large pitches over almost the entire length of the head. do. On the other hand, the board 20 on which the ancillary circuit is mounted is shorter than the board 4, and the pitch of the terminals is also based on the It is smaller than the plate 4 side. First, attach the lead frame to the substrates 4 and 20 in the state shown in Figure 2. and connect it to the terminal 26 etc. by soldering etc. Next, cut the common frame part 28 do. The lead 22 is provided with a pitch changing portion 24 so as not to contact the mounting member 32. , and the pitch is changed midway to match the terminal pitch of the board 20. like this , the boards 4 and 20 can be connected with a smaller connection width than the FPC, and the terminal pitch Connection can be made without any problem with the difference in the number of chips or the mounting member 32.

0012

[Effect of the idea]

This idea provides the following effects. (1) FPC pressure welding is no longer required and leads can be connected by soldering, etc. The width of the card attachment part is small, allowing the width of the image head to be made small. (2) Lead the difference in terminal pitch between the board on the receiver/emissive element side and the board on the auxiliary circuit side. It is possible to absorb this in the pitch changing section of the pitch changer and connect between terminals with different pitches. Also, pin to the lead. By providing the switch change section, the attachment member of the image head can be bypassed. (3) Expensive FPC can be eliminated.

[Brief explanation of drawings]

[Fig. 1] A perspective view showing an exploded state of an image head according to an embodiment.

[Fig. 2] A perspective view showing the connection state of the lead frame of the image head of the embodiment.

[Fig. 3] Cross-sectional view of the image head of the embodiment

[Fig. 4] Bottom view of the image head of the embodiment

[Explanation of symbols]

2 Base plate 4 LED board 6 Light emitting diode array 12 Reference plane 16 Second reference plane 20 Ancillary circuit board 22 Lead 24 Pitch change section 26 Terminal 28 Common frame part 32 Mounting parts

──────────────────────────────────────────────── ─── Continued from front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location H04N 1/036 A 9070-5C

Claims (1)

[Scope of utility model registration request] 1. An image head in which a substrate on which a light emitting and receiving element is mounted is arranged on the inner surface of a housing of the image head, and a board on which ancillary circuits for the light emitting and receiving element are mounted on an outer surface of the housing, each of the above-mentioned boards In addition to providing multiple terminals for lead connection, the terminals of each board are connected with leads, and the lead has a pitch changing part between the connection parts with both terminals, and the light receiving and emitting elements are mounted. An image head characterized by having different lead pitches between the printed circuit board and the board mounted with the ancillary circuits of the light receiving and emitting elements.