JPH0648889Y2 - Image sensor unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to, for example, a contact type image sensor unit which uses a light emitting diode as a light source and is used in a facsimile or the like.

[Prior art]

As shown in FIG. 4, the conventional contact image sensor unit 16 includes the light emitting diode light source array shown in FIGS. 3 (a) (b) (c). In this light emitting diode light source array, chip-shaped light emitting diodes 12 are linearly arranged in the longitudinal direction of the printed board 11 on a long and thin printed board 11. The printed circuit board 11 is provided with a reflection case 13 made of resin or the like for covering the light emitting diode 12. An opening is formed at the tip of the reflection case 13, and a cylindrical lens 14 as an outgoing light imaging rod lens is attached to the opening. As a result, the light ring connecting the light emitting diode 12 and the cylindrical lens 14 is set at a right angle to the surface of the printed circuit board 11. Further, on the lower surface of the printed circuit board 11, an aluminum heat dissipation plate 15 for dissipating heat from the heat emitting light emitting diode 12 through the printed circuit board 11 is provided.

As shown in FIG. 4, the contact image sensor unit 16 has a rectangular parallelepiped aluminum block 17 having a surface in contact with the document surface 18 as an outer frame. A concave portion 17a is formed on the surface of the aluminum block 17 facing the document surface 18, and the optical axis of the light emitted from the light emitting diode light source array forms an angle of 45 degrees with the document surface 18 in the concave portion 17a. like,
The light emitting diode light source array is installed and fixed in an inclined state on the wall surface of the recess 17a. Further, a SELFOC lens array 19 as a reflected light image forming lens that receives the light reflected by the document surface 18 is fixed to a wall portion facing the document surface 18 facing the recess 17a. In addition, an optical path 21 is formed in the aluminum block 17 so that the light passes through the SELFOC lens array 19 and reaches the optical sensor 20 provided on the upper surface of the aluminum block 17.

With the above structure, the light emitted from the light emitting diode light source array becomes an image image of the document surface 18 by irradiating the document surface 18 and then reflecting it, and an image is formed on the optical sensor 20 via the Selfoc lens array 19. To do. Optical sensor
Reference numeral 20 converts the image on the document surface 18 into an electric signal.

[Problems to be solved by the device]

However, in the contact-type image sensor unit 16, the optical axis of the light emitted from the light emitting diode light source array and the optical axis of the reflected light passing through the SELFOC lens array 19 are, for example, 45 degrees as described above. You need to keep the angle. Therefore, when the printed circuit board 11 has the positional relationship with other means as shown in FIGS. 3 (a) (b) (c) and FIG. The distance between the outer ends of the lens array 19 and the lens array 19 in the opposite direction becomes longer. As a result, there is a drawback that the contact image sensor unit 16 cannot be downsized.

Therefore, the image sensor unit of the present invention can be made thin by shortening the distance between the printed circuit board 11 provided with the light emitting diode 12 and the SELFOC lens array 19 in the direction opposite to each other. It is intended to provide an image sensor unit that can be downsized.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the image sensor unit of the present invention is provided with a light emitting diode linearly along the light irradiation surface of the object to be detected, and the light emitted from this light emitting diode is emitted. In the image sensor unit in which the image rod-shaped lens guides the object to be detected, and the reflected light from the object is guided to the light receiving means by the reflected light image forming lens, the substrate is the object to be detected in the reflected light image forming lens. The light emitting diode and the emitted light imaging rod lens are provided substantially parallel to the optical axis in the direction of the light receiving means from the body and substantially perpendicular to the light irradiation surface of the object to be detected. The optical axis that enters the outgoing light imaging rod lens and connects the light emitting diode and the outgoing light imaging lens is
It is characterized in that the light emitting diodes are arranged so as to form an acute angle with respect to the substrate surface on the side of the object to be detected.

[Action]

According to the above configuration, the substrate on which the light emitting diode is provided is provided substantially parallel to the optical axis of the reflected light imaging lens in the direction from the detection target to the light receiving unit and substantially perpendicular to the light irradiation surface of the detection target. ing. In order to obtain this configuration, the light emitting diode and the outgoing light image forming rod lens are such that the light emitted from the light emitting diode directly enters the outgoing light image forming rod lens,
The optical axis connecting the light emitting diode and the outgoing light imaging lens is arranged so as to form an acute angle with the substrate surface on the side of the detected body from the position where the light emitting diode is arranged. Therefore, the present image sensor unit can be made thin by shortening the distance between the outer end portions of the substrate provided with the light emitting diode and the reflected light imaging lens in the direction opposite to each other. Has become.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

As shown in FIG. 1, the array for light emitting diode light source is
Chip-shaped light emitting diodes 2 are linearly arranged along the longitudinal direction of the printed circuit board 1 on the elongated printed circuit board 1. The printed board 1 is provided with two reflective cases 3 and 4 so as to cover the light emitting diode 2. One of the reflection cases 3 is arranged along the edge of the printed circuit board 1, and a supporting portion 3a for holding the cylindrical lens 5 is formed on an obliquely upper portion of the reflection case 3. The other reflection case 4 is located near the light emitting diode 2 and is provided along the light emitting diode 2. An upper portion of the reflection case 4 is formed in a V shape toward the reflection case 3, and a support portion for holding the cylindrical lens 5 is provided at a portion of the reflection case 3 facing the support portion 3a. 4a is formed.

In the space surrounded by both supporting portions 3a and 4a of the reflection cases 3 and 4, the cylindrical lens 5 is used as an outgoing light image forming rod-shaped lens that focuses the light from the light emitting diode 2 on the document surface 6 as a light irradiation surface. Is installed.

In the above array for light-emitting diode light source, the light emitted from the light-emitting diode 2 is directly incident on the cylindrical lens 5, and at least with respect to the substrate surface of the printed board 1 on which the light-emitting diode 2 is arranged, the light-emitting diodes 2 and The positional relationship between the light emitting diode 2 and the cylindrical lens 5 is determined so that the optical axis connecting with the cylindrical lens 5 is set at an acute angle. Then, in this embodiment, the light emitting diode 2 and the cylindrical lens 5 are used.
The optical axis connecting to and is set to form an angle of 45 degrees with the substrate surface of the printed circuit board 1.

As shown in FIG. 2, the light emitting diode light source array constitutes a part of the contact image sensor unit 7. The contact type image sensor unit 7 has an outer frame formed by an aluminum block 8 having a rectangular parallelepiped shape.
The aluminum block 8 is formed with a penetrating portion 8d that penetrates vertically. The penetrating portion 8d is formed with inner surfaces 8a and 8b standing upright at right angles to the original surface 6 so as to face each other. A protrusion 8c having an upper surface parallel to the document surface 6 is formed below the inner surface 8b so as to protrude inward. In the array for light emitting diode light sources, one reflection case 3 is in close contact with the upper surface of the protruding portion 8c, and the printed circuit board 1 is the inner surface.
It is installed inside the aluminum block 8 so as to be in close contact with 8b. Thereby, the optical axis of the light emitted from the light emitting diode 2 is set to form an angle of 45 degrees with respect to the document surface 6. Further, the document surface 6 is provided on a predetermined portion of the other inner surface 8a.
With respect to the optical sensor 10 as a light receiving means which is provided inward from the upper end of the aluminum block 8 provided in parallel with
A SELFOC lens array 9 as a reflected light imaging lens is provided so that the reflected light from the document surface 6 can be imaged. Therefore, the printed circuit board 1 is parallel to the optical axis of the SELFOC lens array 9 in the direction of the optical sensor 10 from the original surface 6 and perpendicular to the original surface 6.

In the above configuration, the contact image sensor unit 7
Then, as described above, the quilt substrate 1 provided with the light emitting diode 2 is substantially parallel to the optical axis of the SELFOC lens array 9 in the direction from the document surface 6 to the optical sensor 10 and perpendicular to the document surface 6. Has become. In order to obtain this structure, the light emitting diode 2 and the cylindrical lens 5 are such that the light emitted from the light emitting diode 2 directly enters the cylindrical lens 5 and the optical axis connecting the light emitting diode 2 and the cylindrical lens 5 is The light emitting diode 2 is arranged so as to form an acute angle with the substrate surface on the document surface 6 side. Therefore, the contact-type image sensor unit 7 is made thin because the distance between the outer end portions of the quilt substrate 11 and the SELFOC lens array 9 in the facing direction is shortened, and the contact image sensor unit 7 is thereby miniaturized. Also, along with this, the aluminum block 8
The volume of the part is reduced and the weight is also reduced.

Also, one inner surface 8b of the aluminum block 8 and the protruding portion 8c
Since the light emitting diode light source array is set with the upper surface of the light emitting diode as a reference surface, it is easy to set the mounting position of the light emitting diode light source array. Further, even if the light emitting diodes 2 on the printed circuit board 1 are misaligned, the tolerance for mounting the light emitting diode light source array to this misalignment becomes large. In addition, the structure of the reflection cases 3 and 4 for holding the cylindrical lens 5 can be simplified.

[Effect of device]

As described above, in the image sensor unit of the present invention, the substrate on which the light emitting diode is provided is substantially parallel to the optical axis of the reflected light imaging lens in the direction from the detection object to the light receiving means and the detection object is irradiated with light. The light emitting diode and the outgoing light image forming rod lens are provided almost perpendicular to the plane, and the light emitted from the light emitting diode directly enters the outgoing light image forming rod lens, and the light emitting diode and the outgoing light image forming lens are formed. The optical axis connecting to and is arranged so as to form an acute angle with the substrate surface on the side of the detected body from the position where the light emitting diode is arranged.

As a result, the present image sensor unit can be made thin by shortening the distance between the outer end portions of the substrate provided with the light emitting diode and the reflected light imaging lens in the opposing direction, and can be made compact. Has the effect.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention. FIG. 1 is a vertical sectional view showing an array for a light emitting diode light source, and FIG. 2 is a vertical sectional view showing a contact image sensor unit. FIGS. 3 and 4 show a conventional example, and FIGS. 3 (a), (b) and (c) are an enlarged front view, a side view and a front view showing an array for a light emitting diode light source, and FIG. It is a longitudinal cross-sectional view showing an image sensor unit. 1 is a printed circuit board (substrate), 2 is a light emitting diode, 3 ...
Reference numeral 4 is a reflection case, 5 is a cylindrical lens (emitted light image forming rod lens), 6 is a document surface (light irradiation surface), 9 is a Selfoc lens array (reflected light image forming lens), and 10 is an optical sensor (light receiving means). Is.

Claims (1)

[Scope of utility model registration request] 1. A light emitting diode is linearly provided on a substrate along a light irradiation surface of an object to be detected, and light emitted from the light emitting diode is guided to the object to be detected by an emitted light imaging rod lens. In the image sensor unit in which the reflected light from the detection body is guided to the light receiving means by the reflected light imaging lens, the substrate is substantially parallel to the optical axis from the detected body in the reflected light imaging lens to the light receiving means. Further, the light emitting diode and the emitted light image forming rod lens are provided substantially perpendicular to the light irradiation surface of the object to be detected, and the light emitted from the light emitting diode directly enters the emitted light image forming rod lens, and this light emission is performed. The image sensor unit is characterized in that the optical axis connecting the diode and the outgoing light imaging lens is arranged so as to form an acute angle with respect to the substrate surface on the object side from the position where the light emitting diode is arranged. And