KR930003476B1 - Facsimile manuscript lighting device - Google Patents

Abstract

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Description

Facsimile manuscript lighting device

Figures 1 (a) and (b) are configuration diagrams using a conventional fluorescent lamp lighting method.

2 is a graph of the illuminance distribution of a fluorescent lamp according to the main scanning width.

Fig. 3 is a graph of the amount of light irradiated to the line image sensor.

4 is a structural diagram of a conventional light shielding plate.

5 is a circuit diagram schematically showing the configuration of the present invention.

6 is a light amount distribution graph according to an embodiment of the present invention.

* Explanation of symbols for major parts of the drawing

1: manuscript 2: fluorescent lamp

3: lens 4: shading plate

5: line image sensor 6: sensor substrate

7: Reflector α: Initial illumination curve

β: Illuminance distribution curve in the state of deterioration of quality after change over time

A: DC power supply unit B: Light-emitting unit

C: light amount control unit x: main scanning width

y: illuminance R1 to Rn: resistance

D1 to Dn: light-emitting diodes (LED).

The present invention relates to a facsimile document lighting apparatus, and in particular, to a facsimile document lighting apparatus that irradiates light onto a document using a light emitting diode (LED).

In the conventional case, facsimile. A photocopier or the like employs an optical system configuration using a fluorescent lamp in order to read the image data of a manuscript, and an example thereof is shown in FIG. In FIG. 1, (a) is a side view and (b) is a plan view. In addition, 1 represents a manuscript, 2 represents a fluorescent lamp, 3 represents a lens, 4 represents a light shielding plate, 5 represents a line image sensor (hereinafter, simply referred to as "CCD"), 6 represents a sensor substrate, and 7 represents a reflector.

As shown in the drawing, in the conventional case, the image data of the original 1 is reversed by illumination of a fluorescent lamp 2 and the lens 3 is moved through the reflector 7 in the conventional case. By passing through, an image is formed on the CCD (5). Then, an output is obtained from the sensor organ 6 which reads it, amplifies the analog signal, converts it to digital, corrects distortion of data, etc., and transmits it to a recording device to obtain a predetermined image. Here, the fluorescent lamp (2) is oscillated by a ballast (not shown), and the illumination (y) distribution of the general fluorescent lamp (2) decreases toward both ends of the fluorescent lamp (2) as shown in Figure 2. Occurs, and the overall illuminance decreases (10 to 30%), such as the shape of the illuminance distribution curve (β) according to the quality deterioration state after a change over time compared to the illuminance (α) at the time of initial use of the fluorescent lamp (2). The width of the illuminance decrease was increased, causing a great problem as an image illuminator. In addition, in order to solve the above problem, a shading plate 4 such as a shading plate was prepared, and the high illuminance (x) of the center was dropped, and the shape of the shading plate 4 as shown in FIG. 1(a) was As shown in Fig. 4, a structure having a shape opposite to the light quantity distribution curve of a fluorescent lamp was made and used. In addition, in order to make the output of the CCD 5 uniform instead of this method, an electrical processing circuit is additionally configured to undergo a complicated and cumbersome adjustment process. Moreover, there was almost no countermeasure for the non-uniformity of the illuminance distribution curve (β) that differs with the aging change of the fluorescent lamp (2). In addition, since conventional fluorescent lamps for facsimiles can obtain high-quality images only when the lighting frequency is 20KHz or higher, high-quality images are required. Accordingly, a stable DC power supply is required. It had a problem.

The present invention has been devised to fundamentally solve the above problems, and uses a plurality of semi-permanent light-emitting diodes (LEDs) to provide a facsimile manuscript illumination device in which the distribution of the amount of light imaged on the line image sensor (CCD) is flat. It has its purpose in providing.

In order to achieve the above object, the present invention comprises a direct current power supply means, a light emitting means connected to the direct current power supply means to irradiate light to the document, and the semi-lighting means and the direct current power supply means are connected to the above. It characterized in that it is composed of a light amount control means for adjusting the amount of light of the light emitting means.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 5 and 6. In the drawing, A denotes a DC power supply unit, B a light-emitting unit, C a light quantity control unit, D1 to Dn a light-emitting diode, R1 to Rn a current control resistor, x a main scan width, and y a illuminance. As shown in the drawing, the present invention provides a direct current power supply unit (A) and a light emitting unit (B) connected to the direct current power supply unit (A), and a light quantity control unit connected to the direct current power supply unit (A) and the light emitting unit (B). Consisting of (C), the light emitting unit (B) is composed of a plurality of semi-permanent light emitting diodes (D1 to Dn) connected in parallel to the direct current power supply unit (A), and the light amount control unit (C) is the It is composed of a plurality of current control resistors (R1 to Rn) that are connected in series to a plurality of light-emitting diodes, respectively, to fix a current value flowing through the light-emitting diode according to each resistance value. And the DC power supply unit (A) is constructed using a known circuit that converts and supplies power to DC. Since the amount of light of the light-emitting diodes D1 to Dn is proportional to the current, it is possible to control the amount of light for each light-emitting diode by adjusting the values of the resistances R1 to Rn connected in series.

In addition, a cylindrical lens rod is attached over the entire length of the LED array to have a super-check distance and a depth of focus within a certain range. As a method for controlling the amount of light used in the present invention, the lighting width (main scanning width) is divided into several, and depending on the divided width, the amount of light of the light-emitting diodes arranged at regular intervals from the center to both ends is set or the light amount of the light-emitting diodes Instead of making the light-emitting diodes (D1 to Dn) constant, the method of arranging the array spacing of each of the light-emitting diodes (D1 to Dn) with a small center and close both ends is used. do. At this time, the resistance value is symmetrical to the left and right based on the center. And in the latter case, the same resistance value is connected.

According to the present invention, the light intensity distribution formed on the CCD 5 through the lens 3 is flattened by performing an effective document illumination function by configuring as described above. At this time, according to the characteristic of the lens 3 that the amount of light by cos ⁴ θ decreases as the optical axis deviates from the optical axis to the periphery according to the half-view angle θ of the general lens 3, the light amount distribution of the main scanning width x of the light emitting diode is It is configured to have a characteristic of 1/cos ⁴ θ (see FIG. 5). At this time, the distribution (a,a') of the upper and lower limits of the roughness distribution curve should be about ±10% to ±15. By reducing this dispersion as much as possible, the illuminance distribution input to the CCD 5 in combination with the cos ⁴ θ curve of the lens 3 can be configured as flat as possible. In addition, the emission colors of the light emitting diodes D1 to Dn constituting the light emitting part are various, but in the case of orange color, the maximum output can be obtained, and generally, it has good adaptability to the CCD 5. In addition, a roof lens having a certain focal length and depth of focus and condensing light generated from the light-emitting part B is installed on the top of the light-emitting part B, and the light-emitting part ( It is constructed by attaching a heat sink integrally to dissipate the heat generated by B).

The present invention configured as described above can be used not only for the illumination system of the facsimile, but also for a halogen lamp, which is a general illumination light source such as a copier, and can be used as a light source for other lighting and reading devices.

The effects of the present invention are as follows. In configuring the lighting device or reading device, quality deterioration due to change over time is eliminated, and ballasts and shading plates are removed by excluding mechanical and electrical shading, which greatly extends the lifespan and simplifies the structure to manufacture cost. To improve economic efficiency.

Claims (8)

In the document illumination device; A direct current power supply means (A), a light emitting means (B) connected to the direct current power supply means (A) to irradiate light on the manuscript, and connected between the light emitting means (B) and the direct current power supply means (A), A facsimile manuscript illumination device, characterized in that consisting of a light amount adjusting means (B) for adjusting the light amount of the light emitting means (B). The method of claim 1, wherein the light emitting means (B) is composed of a plurality of light emitting diodes (D1 to Dn) in which each anode is connected in parallel to the anode (+) of the direct current power supply means (A), The light amount control means (C) is connected to the cathode of a plurality of light emitting diodes (D1 to Dn) constituting the light emitting means (B) in series, respectively, and the cathode of the direct current power supply means (A) on the other side ( A facsimile manuscript illumination device, characterized in that consisting of a plurality of resistors (R1 to Rn) connected in parallel to -). 3. The facsimile manuscript illumination according to claim 2, further comprising a roof lens installed on the light emitting means (B) and condensing light generated from the light emitting means (B) while having a constant focal length and depth of focus. Device. The facsimile manuscript lighting apparatus according to claim 2, further comprising a heat sink integrally attached to one side of the light emitting means (B) to generate heat generated by the light emitting means (B). 3. The facsimile manuscript lighting apparatus according to claim 2, wherein the plurality of light-emitting diodes (D1 to Dn) are arranged at regular intervals, and the light intensity distribution of each light-emitting diode is made to be different from each other. The method of claim 2, wherein the light-emitting diodes (D1 to Dn) constituting the light-emitting means (B) are characterized by flattening the light intensity distribution by arranging a plurality of light-emitting diodes having the same amount of light with a small center and close both ends. Lighting device for facsimile manuscripts. The facsimile according to claim 5 or 6, wherein the plurality of resistors (R1 to Rn) constituting the light amount adjusting means (C) are composed of resistance values determined to have a light amount distribution characteristic of 1/cos ⁴ θ. Manuscript illumination device. The facsimile manuscript lighting apparatus according to claim 2, wherein the light emitting diodes (D1 to Dn) constituting the light emitting means (B) are orange light emitting diodes.