JP3085641B2 - Image input device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer, a color scanner, a bar code reader, an OCR scanner, a facsimile, a portable terminal, a digital copying machine, a plate making machine, a broadcasting television camera using an area CCD, an 8 mm video, an electronic device. The present invention relates to a light amount detecting member used for a still camera or the like and an image input device equipped with the light amount detecting member.

[0002]

2. Description of the Related Art In recent years, communication technology has remarkably advanced, and various information transmitting or information collecting devices have been developed. As for devices used for mobile terminals, miniaturization has become a market need.

As the above-mentioned device (image input device), there is an image sensor for detecting image information.
D type and CIS type (contact type image sensor) can be classified into two types. In the case of the CCD system, a depth of focus of 5 mm or more (permissible characteristic of recognition of deviation from the focal position) can be obtained as compared with the CIS system. The feature is that it increases.

FIGS. 5 and 6 show CCD type image sensors.
FIG. 5 shows the optical path reflected from the original as a mirror.
FIG. 6 is a principle view of an image input device (document reading device 1) which refracts and detects a CCD, and FIG.

According to the document reading apparatus 1 shown in FIG. 5, 2 is a document, 3 is a transparent substrate on which the document 2 is mounted, 4 and 5 are mirrors, 6 is an optical lens, and 7 is a CCD package.
The mirror 5 is arranged in parallel with the transparent substrate 3 on the back side in the figure. Then, a light source (not shown) irradiates the original 2 through the transparent substrate 3, and the reflected light passes through the transparent substrate 3 again, further reflects the mirrors 4 and 5 sequentially, and passes through the optical lens 6 to the CCD package 7. This is a configuration for condensing light.

In the main part of the CCD shown in FIG. 6, an optical lens 6 is fixed to a housing 8 and a CCD package 7 is mounted on a substrate 9.
And the substrate 9 is further fixed to the housing 8. The CCD package 7 has a C
The CD chip 11 is mounted, wire-bonded to the CCD chip 11, and the package 10 is sealed with a sealing glass 12.

To illustrate the dimensions of the document reading apparatus 1, the pixel pitch of the CCD chip 11 is about 7 to 14 μm. When reading an A4 size document 2, the width of the document 2 is 216 mm. The long dimension of the CCD chip 11 is about 24 mm.

Next, the process of assembling the main part of the CCD will be described. First, the method of manufacturing the CCD package 7 will be described. The wafer of the CCD chip 11 is formed by an IC photolithography line such as a C-MOS process, and the wafer is probed. Then, dicing is performed, and thereafter, it is inserted and fixed in a package 10 such as ceramic or plastic, and the CCD chip 11 is wire-bonded to a lead frame. Thereafter, sealing with an optical-grade sealing glass 12 such as BK7 is performed, and thus C
A CD package 7 is obtained.

The CCD package 7 is fixed on the substrate 9 by soldering, and then the substrate 9 is fixed to the housing 8 by screws.
, Mirrors 4 and 5 and an optical lens 6 are disposed at appropriate positions, and a substrate 9, an optical lens 6, mirrors 4 and 5 and a transparent substrate 3 are provided.
The optical setting is completed by finely adjusting the position between them (see JP-A-6-334911 and JP-A-6-347904).

[0010]

However, according to the above-described original reading apparatus 1, when finely adjusting the mutual positions of the members, a large number of adjusting mechanisms including mounting techniques, a large number of adjusting screws and a plurality of adjusting screws are required. Tools are needed,
In addition, skilled skills are required. In addition, there is also a problem that the time required for manufacturing is greatly increased due to such complicated work steps. For example, the CCD package 7 is fixed to the substrate 9 by soldering, but the positional accuracy is very difficult, and the positional accuracy (die mount) of the CCD chip 11 in the CCD package 7 is also very difficult. Also, a ceramic CCD package 7
In the case of (1), there is also a problem in that the dimensions may vary due to firing during the production. And especially 600
In the high-density document reading apparatus 1 called DPI, such optical adjustment becomes a significant problem.

Further, in the conventional document reading apparatus 1, a great deal of optical fine adjustment is required including the transparent substrate 3 and the mirrors 4 and 5, so that a light amount detecting member composed of an optical lens and a CCD is required to be one. There is also a problem that it cannot be manufactured as a part.

In addition, as shown in the CCD package 7 in FIGS. 7 and 8, since the light is transmitted through the sealing glass 12, there is a problem that the optical characteristics are deteriorated.
That is, according to the CCD package 7 of FIG. 7, the incident light is reflected on the surface of the sealing glass 12 or is irregularly reflected to generate stray light, and the light transmittance at the sealing glass 12 is remarkably reduced.
According to the CCD package 7 of FIG.
There is also a problem that the color separation characteristic and MTF are degraded by the prism effect (wavelength dispersion) by the sealing glass 12 because the light is obliquely incident on the bit located at the end of.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a high-performance and low-cost image input apparatus which performs optical adjustment and dimension setting by simple and easy operations, and has improved optical characteristics.

It is another object of the present invention to provide a light quantity detecting member comprising an optical lens and a CCD as a single component which can be placed on a market route, and in which these optical adjustments have been completed in advance. It is in.

[0015]

The light amount detecting member used in the image input apparatus according to the present invention includes an optical lens, a lens fixing housing for fixing the optical lens, a CCD having a light receiving portion exposed, and a CCD. And a circuit board on which the CCD is mounted. The optical lens, the lens fixing housing, and the circuit board form a sealed space, and the dimensions are set so that the sealed space is imaged on the light receiving portion through the optical lens. It is characterized by having done.

Further, in the image input apparatus according to the present invention, a light amount detecting member is provided outside a housing on which a transparent substrate for mounting a document is provided, and the light amount detecting member includes an optical lens and an optical lens. A lens fixing housing, a CCD with a light-receiving portion exposed, and a circuit board on which the CCD is mounted, and a closed space is formed by the optical lens, the lens fixing housing and the circuit board, This sealed space is dimensioned so as to form an image on a light receiving portion through the optical lens, and then a light source and a mirror provided inside the housing are optically adjusted so as to fit the light amount detecting member. The original is illuminated by a light source through a transparent substrate, and the reflected light is reflected by a mirror to be incident on the light amount detecting member.

[0017]

According to the light amount detecting member of the present invention, not the CCD package but the CCD (bare) chip, that is, the CCD in which the light receiving portion is exposed, the optical lens, the lens fixing housing and the circuit are used. Since the closed space is formed by the substrate and the dimensions are set so that the closed space can be imaged on the light receiving unit through the optical lens,
The conventional sealing glass provided in the CCD package is not required, and instead, the above-mentioned closed space is formed so that the light receiving portion of the CCD is not contaminated by dust or dirt. Thus, with the light amount detecting member having such a configuration, a single part is optically adjusted with the housing between the light receiving portion of the CCD and the optical lens, and a product for that purpose can be manufactured.

Further, the image input apparatus of the present invention has a configuration in which a light source and a mirror are provided inside a housing on which a transparent substrate for mounting a document is provided, and the light amount detecting member is provided outside. For the light amount detection member that has already been optically adjusted,
Further, the device is provided with the housing. Therefore, since the portion of the optical adjustment can be limited to the light amount detection member, it is sufficient to first adjust the light amount, and furthermore, the light source and the mirror may be optically adjusted to match the optically adjusted light amount detection member,
In this way, fine adjustment of the mutual position of each member can be distinguished, so that a complicated adjustment mechanism and a large number of adjustment screws and jigs are not required as in the related art, and more skilled technology is also required. As a result, optical adjustment can be performed by simple and easy work, and a low-cost image input device can be provided.

Furthermore, in the present invention, since the optical glass for sealing the CCD package which has conventionally been provided between the optical lens and the CCD is not used, the light passing through the optical lens is used by the optical glass. No surface reflection, no stray light due to diffuse reflection, and
The color separation characteristics and the MTF do not deteriorate, and as a result, a high-performance and highly reliable light-amount detecting member and an image input device with improved optical characteristics can be provided.

In addition, by eliminating the need for a CCD package, the size and space are correspondingly reduced, thereby meeting the needs for miniaturization in the market for devices for portable terminals and the like.
Further, it is possible to provide an image input device which has been further reduced in size.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS.
FIG. 1 is a sectional view of the light amount detecting member 13 of the present invention, and FIG.
FIG. 3 is a plan view of the CCD with the light receiving unit exposed. FIGS. 3 and 4 are cross-sectional views of a document reading apparatus as the image input apparatus of the present invention.

According to the light amount detecting member 13 of FIG. 1, reference numeral 14 denotes a generally conical lens fixing housing made of polycarbonate containing glass filler, and the optical lens 15 is fixed inside the cylindrical body. A circuit board 16 having a thickness of 8 mm is fixed to a portion opposed to 15, thereby forming a sealed space 18 by the optical lens 15, the housing 14 and the circuit board 16, and further exposing a light receiving portion on the circuit board 16. The CCD 17 in the state (bare chip shape) is fixed,
Each of the electrodes is electrically connected to the circuit board 16 by a bonding wire 18. And 19 is the circuit board 16
Is a reinforcing plate made of an aluminum plate, 20 is a screw for fixing the circuit board 16 and the reinforcing plate 19 to the housing 14, and 21 is a connector.

In the CCD 17 shown in FIG. 2, reference numeral 22 denotes a light receiving section in which a large number of light receiving elements (CCD bare chips) are arranged; 23, a bonding pad for bonding each light receiving element with a gold wire; and 24, a positioning pad. Reference numeral 25 denotes a positioning marker, 26 denotes a 10-pin connector, and 27 denotes tantalum for noise suppression.

Next, a method of manufacturing the light amount detecting member 13 having the above configuration will be described. (1) First, a circuit board 16 having one or both main surfaces plated with gold is used. If the board thickness is 2 mm or less, a reinforcing plate 19 is used. Then, for dust prevention measures, the through holes are sealed with a resist or the like. If the reinforcing plate 19 is used, it is preferable to ground it for noise suppression.

(2) Next, a positioning marker 25 provided on the circuit board 16 or a positioning hole 24
The CCD 17 is placed on the circuit board 16 while automatically recognizing the position. According to experiments by the present inventors, the recognition error was ± 5 μm or more, and the mounting error was ± 5 μm or less.

(3) The CCD 17 is mounted on the circuit board 16. In this mounting, an IC adhesive is used and fixed through the adhesive. According to the experiments of the present inventors, the CCD 17
By further fine-tuning the position, the mounting error could be reduced to ± 2 μm or less.

(4) In the case 14 made of polycarbonate, Zylon, metal, or the like manufactured by precision injection molding, the position where the optical lens 15 is to be disposed can be determined before molding. A plastic optical lens 15 is ultrasonically welded to a simple housing 14. However, when the glass optical lens 15 is used, it is press-fitted and fixed.

The inventor of the present invention has proposed that when the CCD 17 has a pixel pitch of 14 μm and 2048 light receiving elements (pixels) and reads an A4 size original (the long dimension of the light receiving section 22 is 14 μm × 2048). = 28.6 mm), a die mounter manufactured by Kyushu Matsushita Electric Co., Ltd. (product N
o. D / M-5200), the recognition and mounting were performed according to the above-described manufacturing method. As a result, errors ΔZ, ΔX, ΔY, and θ in the direction X, the direction Y, and the angle θ with respect to the recognition site Z as shown in the CCD 17 of FIG. Δθ was as follows.

ΔX = 5 μm ΔY = 5 μm ΔZ = 10 μm
Δθ = tan −1 (ΔY / X) = 0.005 / 28.6 =
By the way, in the conventional document reading apparatus 1, ΔX = 800 μm, ΔY = 500 μm, ΔZ
= 500 μm, Δθ = tan -1 (ΔY / X) = 0.5 /
28.6 = 1.0157 °.

Thus, in the light amount detecting member 13 having the above structure, the closed space 18 is formed by the optical lens 15, the housing 14 and the circuit board 16, and the closed space 18 is focused on the light receiving section 22 through the optical lens 15. Since the light receiving portion 22 is not contaminated by dust and dirt, etc., the size of the light receiving portion 22 is prevented from being contaminated, and a single product is produced in which the optical adjustment is performed by using the housing 14 between the light receiving portion 22 and the optical lens 15. Parts. In addition, by eliminating the need for a CCD package, the size and space are reduced accordingly, thereby achieving downsizing.

Next, FIGS. 3 and 4 show the construction of a document reading apparatus in which the light amount detecting member 13 is incorporated. The same parts as those in FIG. 5 are denoted by the same reference numerals.

According to the document reading apparatus 28 shown in FIG. 3, a light source 30 composed of, for example, LEDs and mirrors 4 and 5 are provided inside a housing 29 provided with the transparent substrate 3 on which the document 2 is mounted.
And the light amount detecting member 13 is disposed outside, and the light source 30 is provided.
Irradiates the original 2 with light through the transparent substrate 3 and refracts the reflected light path by the mirrors 4 and 5 so that the light amount detecting member 13
This is a configuration in which the light is made incident.

Thus, the original reading apparatus 28 having the above-described structure is used.
In the above, the light source 30 and the mirrors 4 and 5 need only be optically adjusted and dimensioned so as to be compatible with the optically-adjusted light amount detection member 13. As a result, the optical adjustment can be performed by a simple and easy operation. .

According to the experimental results of the present inventors, 4 lp /
The MTF when scanning a black-and-white original of 80 mm is 80% at the maximum at the central portion of reading, and 50% at the peripheral portion of scanning.
%. Further, the focal depth is 10 mm, the peak difference of the read signal dark output is 3 mV, 1026 gradations, 0.1 ms
Excellent characteristics of ec / line were obtained. And
The assembling speed of the document reading device 28 was also reduced to about 2/3 as compared with the related art. Further, as the light amount detecting member 13, an A4 type 600D
The one for PI full color scanner or the one for A3 type 400DPI digital copier,
Similarly, excellent evaluation results were obtained.

Further, according to the original reading apparatus 31 shown in FIG. 4, another kind of light amount detecting member 33 is arranged outside the housing 32.
Is an optical lens, 35 is a lens fixing housing, 36 is a CCD
17 on which the enclosed space 3 is formed by the optical lens 34, the lens fixing housing 35 and the circuit board 36.
7, and the dimensions are set so that the closed space 37 is focused on the light receiving section 22 through the optical lens 34.

A light source 39 and a mirror 4 are provided inside a housing 32 having a transparent substrate 38 on which the original 2 is mounted.
0, 41, and 42, and a transparent substrate 38 is provided by a light source 39.
The document 2 is irradiated with light through the
In this configuration, the light is refracted by 0, 41, and 42 and enters the light amount detection member 33.

Thus, the original reading apparatus 31 having the above-described configuration is used.
In this case, the light source 39 and the mirrors 40, 41, and 42 may be optically adjusted so as to be compatible with the optically-adjusted light amount detection member 33. As a result, the optical adjustment can be performed by a simple and easy operation.

It should be noted that the present invention is not limited to the above embodiment, and various changes and improvements can be made without departing from the gist of the present invention.

[0039]

As described above, according to the light amount detecting member of the present invention, even if the optical glass for sealing the CCD package is not required, the light receiving portion of the CCD is prevented from being contaminated by dust and the like. The optical adjustment is carried out by using a housing between the light receiving unit and the optical lens of the optical lens, and as a result, it becomes one commercialized electronic component, and as a result, it corresponds to the general-purpose light amount detecting member of the present invention. Therefore, it can be used for image input devices of various shapes.

Further, the image input apparatus of the present invention has a configuration in which the already-adjusted light amount detecting member of the present invention is arranged, and requires a complicated adjusting mechanism and a large number of adjusting screws and jigs as in the prior art. The optical adjustment can be performed by a simple and easy operation, and a low-cost image input apparatus can be provided.

Further, in the present invention, since the glass for encapsulating the CCD package is not used, a high-performance and highly-reliable light-quantity detecting member and an image input device with improved optical characteristics can be provided. In addition, it is possible to provide an image input apparatus that has been further miniaturized in response to the need for miniaturization in the market of devices for mobile terminals and the like.

Therefore, a computer, a color scanner, a bar code reader, and the like using the image input device of the present invention
Scanners for OCR, facsimile machines, portable terminals, digital copiers, plate making machines, and broadcasting TV cameras using area CCDs, 8 mm video, electronic still cameras, etc., offer the advantages of low cost, miniaturization, and high reliability. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a light amount detection member of the present invention.

FIG. 2 is a plan view of a CCD.

FIG. 3 is a cross-sectional view of the image input device of the present invention.

FIG. 4 is a cross-sectional view of the image input device of the present invention.

FIG. 5 is a cross-sectional view illustrating the principle of a conventional document reading device (image input device).

FIG. 6 is a cross-sectional view showing a schematic configuration of a main part of a CCD in a conventional document reading apparatus.

FIG. 7 is an enlarged sectional view of a main part of a CCD package in a conventional document reading apparatus.

FIG. 8 is an enlarged sectional view of a main part of a CCD package in a conventional document reading apparatus.

[Explanation of symbols]

 13, 33 Light amount detecting member 14, 35 Lens fixing housing 15, 34 Optical lens 16, 36 Circuit board 18, 37 Sealed space 17 CCD 22 Light receiving section 28, 31 Document reading device 29, 32 Housing 30, 39 Light source 4 , 5, 40, 41, 42 mirror

────────────────────────────────────────────────── ─── of the front page continued (72) inventor Nariaki Tanaka Kyoto-shi, Kyoto Yamashina-ku, Higashinokitainoue-cho, 5th place of 22 Kyocera Corporation in the examiner Masahiro Ono (58) investigated the field (Int.Cl. ⁷ , DB name) H04N 1/028

Claims (1)

(57) [Claims] A light amount detecting member disposed outside a housing having a transparent substrate on which a document is mounted;
The material is an optical lens and a lens fixing the optical lens
Housing, a CCD with a light receiving unit exposed, and the CCD
And a circuit board on which the optical lens and the lens are mounted.
A closed space is formed by the housing for fixing and the circuit board.
Focus the enclosed space on the light-receiving part through the optical lens.
And then set inside the housing.
Adjust the light source and mirror so that they are compatible with the light amount detection member.
And optical adjustment, the original is irradiated with light through the transparent substrate by the light source, the reflected light mirror - image input apparatus characterized by the so that construction brought incident on the light quantity detecting member is reflected by the.