KR930010141B1 - Contact image sensor - Google Patents

Abstract

The device comprises a light source (11) LED, light emitting diode for radiating some light for sensing the shading of a manuscript, a signal processing circuit (16) for amplifing and converting the signal of the sensed light, a drive ball plate (18), a connector (20), a reflecting mirror (21), a sensor base plate (17), an image sensor chip (15), a mirror (12). The device improves the construction of a contact image sensor, and decreases the size.

Description

Tight image sensor

1 is a cross-sectional view of a close-type image sensor according to the prior art.

2 is a block representing the operating characteristics of FIG.

3 is a block diagram showing an analysis of the functional part configuration of FIG.

4 is a cross-sectional view of a close-up image sensor according to the present invention.

The present invention relates to an image sensor for sensing an image, and more particularly, to a structure of a close type image sensor. In general, an image sensor detects an image and outputs a predetermined signal, and its application field is a component widely applied to an electronic copy machine, an electronic file, a facsimile, an image processor, and a financial device.

The structure of the close-type image sensor according to the prior art is shown in FIG. FIG. 1 is a cross-sectional view, and the operation characteristic according to the configuration of FIG. 1 is blocked and shown in FIG. 3 is a diagram illustrating an analysis of the functional components of FIG. 1. FIG. 1 of the prior art is a catalog of "Mitsubishi image sensor" published in February 1989. Please refer to the catalog except the following description.

The configuration of FIG. 1 includes a light emitting diode (LED) array 1, a document 2 that is brought into close contact with glass 2 and an upper end of the glass 2, a rod lens array 4, and an image. Sensor chip (also called photoelectric conversion element) 5, signal processing circuit section 6, sensor substrate 7, housing 8, connector 9, flexible printed circuit board (PCB) board) 10. Note that in the above configuration, the sensor substrate 7 mounts the image sensor chip 5 and the signal processing circuit portion 6. The housing 8 is a word commonly used in this field, such as, for example, a “frame”. In the configuration of FIG. 1, the light emitting diode array 1, the glass 2, and the rod lens array ( 4) and the sensor substrate 7 are mounted. Based on the structure of FIG. 1, the operation characteristic is demonstrated with reference to FIG. Light emitted from the light source of the light emitting diode array 1 is irradiated onto the document 3 through the glass 2. When the original 3 is black, for example, according to the shade of the original 3, since the irradiated light is absorbed, the reflected light is not irradiated to the rod lens array 4, When the document 3 is light or white, for example, the irradiated light is reflected and is connected to the rod lens array 4, which is a reflected light source cursor, to be uprighted and to compensate for the sensor substrate ( The image sensor chip 5, which is a photoelectric change element of 7), is incident. The incident light is converted into a photocurrent, and is output at 25 to 50 mV according to the shade of the document 3, stabilized and amplified by the signal processing circuit 6, and output through the connector 9.

The light emitting diode array 1 of FIG. 1 is typically composed of a light emitting diode chip 1A and a chip resistor on a substrate, and at least 6 mm of substrate width is required to mount these components. 3) In order to maintain a constant light quantity distribution on the surface, it is determined by h, which is the distance from the surface of the light emitting diode chip A to the surface of the original 3, as shown in FIG. In the case of the SMD type LED chip, when the h is 10 mm, the pitch between the chips is 7.8-8.0 mm, and in the case of the CDB type LED chip, the pitch between the chips is 4.0 mm. As described above, the maximum radiation axis of the light emitting diode chip 1A is arranged to be 45 ° with the optical axis of the rod lens array 4 for an optimal light source arrangement. The distance between the surface of the document 3 and the image sensor chip 5 is determined by a total conjugate (TC) of the rod lens array 4, and the rod lens array 4 is a conventional product. For example, in the case of SLA20, the TC is 14.4 mm (wavelength 570 nanometers (nm)). Therefore, in the structure as shown in the first diagram, even if optimized as a close-type image sensor in terms of components, it is difficult to reduce the size to less than the width "16mm" and the height "17mm". In addition, since the spiral image sensor chip 5 and the signal processing circuit part 6 are mounted on the same sensor substrate 7, when the connector 9 is directly connected to the sensor substrate 7, mechanical impact at the time of connection is achieved. The connector 9 is actually connected to the sensor substrate 7 through the flexible PCB 10 because there is a risk that the output characteristics of the image sensor chip 5 are transferred to the image sensor chip 5. Therefore, when the flexible PCB 10 and the connector 9 are connected and the power line of the light emitting diode array 1 is connected with the connector 9, soldering is performed. Handwork requires poor productivity and high manufacturing costs.

In addition, since the light source of the light emitting diode array 1 passes through the glass 2 when it enters the surface of the document 3, "Snell's law" {this represents the following equation. "T" = | R / A | ^{2 "} ," π = n ₂ cos θ ₂ / n ₁ (cosθ ₁ × | T / A | ^{2 "} ," Rp / Ap = tan (θ _1- θ ₂ ) / tan (θ ₁ + θ ₂ ) "," Rs / As = -sin (θ ₁ -θ ₂ ) / sin (θ ₁ + θ ₂ ) "In the above formula, T: energy reflectance, π: energy transmittance, A: incident light The amplitude of the vector, R: the amplitude of the reflected light vector, T: the amplitude of the oyster beta vector, P: the component oscillating in the plane of incidence, S: the component oscillating vertically in the plane of incidence. The light transmittance in the glass 2 is limited to about 95% by the omission of the present invention. Accordingly, an object of the present invention is to provide an optimal space in the arrangement of the functional components in the configuration of the close-up image sensor. It is another object of the present invention to reduce the number of parts, to improve productivity in the manufacturing process, and to reduce cost through automation. There yimeji the sensor to provide.

In order to achieve the object of the present invention, the present invention is a close-type image sensor having a transparent body for supporting a predetermined document and detecting the light and shade of the original using the incident and reflection of light through the transparent body and the output accordingly An integrated sensor substrate of a photoelectric conversion element positioned at a lower end of the transparent body and converting a predetermined sensed light into a photocurrent, and a light source unit amplifying a predetermined light located separately from the sensor substrate at a lower end of the transparent body and amplifying the light. It is characterized in that the close-up image sensor having a driving substrate with a built-in signal processing circuit for the. In the above, it should be noted that the signal processing portion of the sensor substrate and the driving substrate is electrically connected by the flexible PCB.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Prior to the description, it should be noted that the present invention can arbitrarily adjust the imaging point of the document by adjusting the incident angle and the reflection angle using a reflection mirror located at the bottom of the document. A close-up image sensor according to the invention is shown in FIG. The configuration of FIG. 4 includes the light emitting diode array 11 located at the vertical lower end of the original, the glass 12, the original 13 conveyed from the upper end of the glass 12, and the glass 12. A load lens array 14 positioned at a lower end and parallel to the surface of the glass 12, an image sensor chip 15 for detecting a light and shade of light entering through the rod lens array 14, and a signal processing circuit unit 16. ), A sensor substrate 17 on which the image sensor chip 15 is mounted, a drive substrate 18 on which the signal processing circuit portion 16 and a light emitting diode array are mounted, the drive substrate 18, and a sensor substrate (17) and the housing (19) on which the rod lens array (14) is mounted, the connector (20) located at the lower end of the driving substrate, and the contrast of the original (13) are reflected to the rod lens array (14). Flexible to electrically connect the reflection mirror 21, the signal processing circuit section 6 and the sensor substrate 17 for It is made of a PCB (22). The operation characteristic of FIG. 4 based on the said structure is demonstrated. The reflective surface of the reflective mirror 21 is formed by coating with a metal (for example, chromium, aluminum, etc.) and an oxide film on the surface of the glass lens 12 in the direction of the rod lens array 14. The reflected light reflected from the reflective mirror 21 surface coincides with the optical axis of the rod lens array 14. Further, a light emitting diode array 11 on the drive plate 18 is formed on the surface of the original 13 having the same angle of incidence as the reflected light above and below the surface of the original 13.

Therefore, the light emitted from the light emitting diode array 11 is incident perpendicularly to the surface of the original 13 and, for example, the density of the original 13 depends on the lightness of the original 13 on the surface of the original 13. Is light or white, the light emitted from the surface of the document 13 is reflected back from the reflecting mirror 21, is incident to the optical axis of the rod lens array 11, is focused, is upright equilibrium compensation and the sensor The image sensor chip 15 which is a photoelectric conversion element on the substrate 17 is incident. The incident light is converted into photocurrent by photoelectric conversion, signal converted and amplified by the signal processing circuit 16, and output through the connector 20. (In the above, the signal processing circuit 16 and the sensor substrate 17 is electrically connected by the flexible PCB 22)

It should be noted that the close-type image sensor shown in FIG. 4 is an optimal embodiment for realizing the idea of the present invention, and the position of each component may be slightly changed.

As described above, the close-type image sensor according to the present invention separates the sensor substrate from the driving substrate to minimize the sensor substrate, and mounts the light emitting diode array 1 and the signal processing circuit part 6 on the same PCB substrate. As a result, the soldering operation by manual labor, which is a problem in the related art, may be omitted in the present invention, and thus, the cost may be reduced by improving productivity. In addition, the present invention optimizes the configuration of the close-type image sensor to achieve a size reduction of about 36% compared to the conventional close-type image sensor.

Claims (7)

A close-up image sensor comprising a transparent body for supporting a predetermined original and detecting the lightness of the original by using the incidence and reflection of light through the transparent body, and outputting accordingly, the predetermined image sensor for detecting the lightness of the original A close-up image sensor comprising a driving substrate having a light source unit for emitting light and a signal processing circuit unit for signal conversion and amplification of the detected light at the lower end of the transparent body. The optical image sensor of claim 1, wherein the close-up image sensor comprises a reflection mirror for reflecting light reflected from the light source and re-reflecting light reflected from the light source, and an optical axis coinciding with a traveling direction of light reflected from the reflection mirror. And a sensor substrate having a rod lens array and a photoelectric conversion element disposed at a rear end of the rod lens array to convert light emitted through the rod lens array into photocurrent. The close-type image sensor according to claim 1, wherein the light reflected back from the reflecting mirror is incident to and coincided with the optical axis of the rod lens array and is focused upright. A close-up image sensor having a transparent body for supporting a predetermined document and detecting the shade of the original using the incident light and reflection of light through the transparent body, and outputting the same, wherein the image is located at a lower end of the transparent body and has a predetermined sense. And a sensor substrate incorporating a photoelectric conversion element for converting the converted light into a photocurrent, and a driving substrate incorporating a light source unit which is separated from the sensor substrate and emits a predetermined light at a lower end of the transparent body, and a signal processing circuit unit for amplification. Close-type image sensor, characterized in that. The method according to claim 4, wherein the close-up image sensor is located between the reflective mirror and the reflective mirror for reflecting back predetermined light reflected by the driving substrate is emitted from the light source unit and reflected into the transparent body, And a rod lens array having an optical axis coinciding with a traveling direction of light reflected back from the reflection mirror. 5. The close-up image sensor according to claim 4, wherein the signal processing circuit portion of the sensor substrate and the driving substrate are electrically connected by a flexible printed circuit board. A close-type image sensor having a transparent body for supporting a predetermined document and detecting the light and shade of the original using the incident and reflection of light through the transparent body, and outputting the same, wherein the image is located at the lower end of the transparent body A sensor substrate incorporating a photoelectric conversion element for converting light into a photocurrent, a light source element portion disposed at a lower end of the transparent body, and emitting a predetermined light to detect a shade of the original, and formed on the same substrate together with the light source element A signal processing circuit unit for converting and amplifying the signal converted into the photocurrent, a reflection mirror for reflecting back predetermined light emitted from the light source element unit of the driving substrate and reflected on the transparent body, and the reflection mirror; The optical axis is located between the sensor substrates and in the traveling direction of the light reflected back from the reflection mirror. Yimeji contact type sensor that is characterized by having a rod lens array in which a value.