JPH0918655A - Linear light source device - Google Patents

Abstract

PURPOSE: To provide a uniform linear lighting by controlling a luminous intensity/lighting time of each point lighting source so as to make the luminous quantity from each point light source of P line light source equal to each other. CONSTITUTION: A luminous quantity of plural LED chips 8 is controlled respectively by an LED drive control circuit 11. The luminous quantity is controlled by regulating current applied to each chip 8 or adjusting the lighting time of the chip 8 in a read time of one line. As the adjustment method of the light emitting time, the rate of light emission time of each chip 8 in a read time by an image sensor 5 is changed or the frequency of pulse lighting of each chip 8 is changed. Thus, ununiformity of the luminous quantity of the linear light source and ununiformity of emitted luminous multi-value processing due to shading are corrected to obtain a uniform linear emitted light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear light source device for reading an image, which is used in a facsimile, a copying machine, an image scanner and the like.

[0002]

2. Description of the Related Art A linear light source device for reading an image is used in a facsimile, a word processor, a copying machine, an image scanner and the like. In order to recognize image information by an image sensor, a linear light source is desired to be read on a document surface to be read. It irradiates light.

FIG. 31 is a diagram showing a structure of a main part of a reduction type image scanner. A linear light source is composed of a cold cathode fluorescent lamp 1, an original 2, a reflecting mirror 3, an image forming lens 4 and an image sensor 5. An image in which a plurality of photodiodes are arranged in a line through the imaging lens 4 after the reflected light of the thin linear irradiation light emitted from the cold cathode fluorescent lamp 1 to the original 2 is bent by the reflecting mirror 3. The image information received by the sensor 5 and decomposed into minute pixels by the large number of photodiodes is taken out as an electric signal corresponding to the density of each pixel.

FIG. 32 is a diagram showing the output of the image sensor 5 (hereinafter referred to as "sensor output") when a white original is read by the reduction type image scanner. The sensor output has a uniform output level in the reading line. Instead, a phenomenon called shading occurs in which the output at the end becomes small. This shading is caused by a decrease in the brightness of both ends of the linear light source and a decrease in the peripheral light amount of the imaging lens, and the S / N in the reading line changes, so it is difficult to read accurate image information. There is a problem.

FIG. 33 shows, for example, Japanese Patent Laid-Open No. 6-296221.
FIG. 34 is a cross-sectional view showing the configuration of the main part of the contact type image scanner disclosed in Japanese Patent Publication No. JP-A-2004-34187, and FIG. The same reference numerals as 32 denote the same or corresponding portions, 6 is a linear light source, 7 is a wiring board,
Reference numeral 8 is an LED chip forming a point-like light emitting source arranged in a line on the surface of the wiring board 7, 9 is an LED drive circuit for driving the LED chip 8, and 10 is a rod lens array.

In this contact type image scanner, a thin linear light is emitted from the linear light source 6 onto the surface of the original 2, and the reflected light reflected by the illuminated surface passes through the rod lens array 10 and the image sensor 5. The image information that is received by and is decomposed into minute pixels is taken out as an electric signal corresponding to the density of each pixel.

FIG. 35 is a diagram showing the sensor output of this contact type image scanner. Usually, the LED chip has 1.
There is a variation in the amount of emitted light of about 4 to 2 times, and this variation changes the S / N in one line of the sensor output, making accurate reading difficult. If the LED chips are selected in order to solve this problem, there is a problem that the cost increases.

[0008]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above problems, and corrects the unevenness of the light emission amount of a linear light source and the unevenness of the irradiation light amount due to shading. It is an object of the present invention to obtain a linear light source device capable of obtaining a uniform linear irradiation light.

[0009]

According to a first aspect of the present invention, a linear light source in which a plurality of point light emitting sources are linearly arranged on a surface of a wiring board, and each point light source of the linear light source is provided. The lighting drive control means adjusts at least one of the light emission intensity and the light emission time of each point light emission source so that the amount of light emitted from the light emission source becomes the same.

According to a second aspect of the present invention, the linear light source device of the first aspect is represented by each emission intensity of each of a plurality of point emission sources or each emission intensity ratio, or each emission time or each emission time ratio. The lighting drive control means drives a plurality of point emission sources on the basis of the above lighting conditions.

According to a third aspect of the present invention, the linear light source device according to the first aspect is provided with a light source moving means for moving the linear light source in the longitudinal direction.

According to a fourth aspect of the present invention, in the linear light source device according to the first aspect, at least one of the emission intensity or the emission time of each point light source is adjusted so that the amount of light emitted from each point light source is the same. A lighting drive control means for adjusting one of them is provided.

According to a fifth aspect of the present invention, in the linear light source device according to the fourth aspect, the respective emission intensities or the ratios of the emission intensities of the plurality of point emission sources, or the emission times or the ratios of the emission times are stored. It is provided with a storage means for performing.

According to a sixth aspect of the present invention, the linear light sources are arranged linearly in the longitudinal direction on the surface of the wiring board, the wiring board facing the original surface being concave in the longitudinal direction. It is composed of a plurality of point emission sources.

The invention of claim 7 is the invention of claims 1, 2, 4, and 6.
In the linear light source device according to any one of 1 above, a first focus for converging light generated by the linear light source inward of the linear irradiation light, and a direction orthogonal to the direction of the linear irradiation light. It is provided with a condenser lens having a second focal point for condensing in the direction.

The invention of claim 8 is the invention of claims 1, 2, 4, and 6.
In the linear light source device according to any one of 1 above, a first focus for converging light generated by the linear light source inward of the linear irradiation light, and a direction orthogonal to the direction of the linear irradiation light. And a concave mirror having a second focal point for converging light in the direction.

[0017]

According to the lighting drive control means of the present invention, at least one of the emission intensity or the emission time of each point light source is adjusted so that the amount of light emitted from each point light source of the linear light source becomes the same. Control one.

The storage means of the invention of claim 2 stores the lighting conditions of the plurality of point light emitting sources, and the lighting drive control means comprises:
This lighting condition is read out and controlled so that the light emission amounts of the plurality of point light emission sources become equal.

The linear light source moving means according to the third aspect of the present invention moves the linear light source in the longitudinal direction thereof at a distance of about half the arrangement interval of the point light emitting sources.

The linear light source moving means of the invention of claim 4 moves the linear light source in the longitudinal direction thereof, and the lighting drive control means makes the light amounts emitted from the respective point light emitting sources the same. At least one of the emission intensity and emission time of each point emission source is controlled.

The linear light source moving means of the invention of claim 5 moves the linear light source in its longitudinal direction, the storage means stores the lighting conditions of a plurality of point light emitting sources, and the lighting drive control means is the above-mentioned. The lighting conditions are read out from the storage means, and the light emission amounts of the plurality of point light emission sources are controlled to be equal.

In the linear light source of the invention as defined in claim 6, since a plurality of point-like light emitting sources are linearly arranged in the longitudinal direction of the surface of the wiring substrate formed in the concave surface, the peripheral portion is the illuminated surface. , And the central part is far, so that the amount of linear irradiation light on the irradiation surface becomes uniform.

The condensing lens of the invention of claim 7 condenses the linear light generated by the linear light source at the first focus into a thin linear shape on the irradiation surface, and at the second focus, the linear light. The linear light generated by the light source is condensed in a direction orthogonal to the linear irradiation light.

In the concave mirror of the invention of claim 8, the optical path of the linear light generated by the linear light source is bent at the first focal point to be condensed into a thin linear shape on the irradiation surface, and at the second focal point The optical path of the linear light generated by the linear light source is bent and condensed in a direction orthogonal to the linear irradiation light.

[0025]

【Example】

Embodiment 1 FIG. 1 is a cross-sectional view showing the configuration of a main part of a reduction type image scanner using a linear light source device according to a first embodiment of the present invention. The same reference numerals as those in FIGS. 32, 34 and 35 denote the same or corresponding parts. The linear light source 6 has the same structure as the conventional example shown in FIG. In the figure, 1
Reference numeral 1 denotes an LED drive control circuit which constitutes a lighting drive control means, and the linear light source 6 and the LED drive control circuit 11 constitute a linear light source device.

Next, the operation will be described. Multiple LEs
The amount of light emitted from each of the D chips 8 is controlled by the LED drive control circuit 11. The amount of light emission is performed by adjusting the amount of current passed through each LED chip 8 or by adjusting the light emission time of the LED chip 8 within the reading time of one line. As a method of adjusting the light emission time, there are a method of changing the ratio of the light emission time of each LED chip 8 within the reading time by the image sensor 5, a method of changing the number of times each LED chip 8 is pulse-lighted, etc. The light emission amount within one line reading time of the image sensor 5 can also be adjusted by using the method.

FIG. 2 is a diagram showing the sensor output when a white original is read by the linear light source device 6 of the first embodiment. The solid line in the figure shows the sensor output when the LED drive control circuit 11 is operated. The broken line shows the sensor output when the LED drive control circuit 11 is not used. As shown in the figure,
When the LED drive control circuit 11 is not operated, the sensor output is low at both ends, and the sensor output is not uniform due to the variation of the LED chip 8. When the light emission amount of the LED chip 8 is controlled to be the same, a uniform sensor output can be obtained.

Embodiment 2 FIG. FIG. 3 is a perspective view of a linear light source device according to a second embodiment of the present invention, in which a condenser lens is added to the linear light source device of the first embodiment. In FIG. 3, the same reference numerals as those in FIGS. 1 and 34 denote the same or corresponding portions, 12 is a condenser lens, and 13 is an irradiation surface of the original 2.

FIG. 4 is a diagram showing the optical action of the second embodiment, FIG. 4 (a) shows the intensity distribution of the irradiation light on the reading line, and FIG. 4 (b) shows the reading line. It is the figure which showed the intensity distribution of the irradiation light of the direction orthogonal to.

Next, the operation will be described. The light emitted from the LED chip 8 is diffused in the reading line direction by the condenser lens 12, and is condensed in the direction orthogonal to the reading line to reach the irradiation surface 13. Therefore, the light emitted from the plurality of LED chips 8 in the direction of the reading line is superposed and uniformized, and the light in the direction orthogonal to the reading line is condensed to increase the density, so that the intensity of the irradiation light is uniform. The amount of irradiation light increases.

Embodiment 3 FIG. FIG. 5 is a perspective view of a linear light source device according to a third embodiment of the present invention, in which a concave mirror is added to the linear light source device according to the first embodiment. 5, the same reference numerals as those in FIG. 3 indicate the same or corresponding portions, and 14 is a concave mirror.

FIG. 6 is a diagram showing the optical action of the third embodiment, FIG. 6 (a) shows the intensity distribution of the irradiation light on the reading line, and FIG. 6 (b) shows the reading line. It is the figure which showed the intensity distribution of the irradiation light of the direction orthogonal to.

Next, the operation will be described. The light emitted from the LED chip 8 has its optical path bent by the concave mirror 14, is diffused in the reading line direction, and is condensed in the direction orthogonal to the reading line direction to reach the irradiation surface 13. Therefore, the light emitted from the plurality of LED chips 8 in the reading line direction is overlapped and made uniform, and the light in the direction orthogonal to the reading line direction is condensed and the density increases, so that the intensity of the irradiation light is increased. The amount of irradiation light increases evenly.

Embodiment 4 FIG. 7 is a diagram showing a linear light source device according to a fourth embodiment of the present invention. The same reference numerals as those in FIG. 3 denote the same or corresponding portions, and 15 denotes each LED chip 8
Lighting conditions in which the light emission amounts of the LED chips 8 are the same, that is, the lighting conditions represented by each light emission intensity or each light emission intensity ratio of each LED chip 8 or each light emission time or each light emission time ratio. is there.

Next, the operation will be described. The LED drive control circuit 11 reads out the lighting conditions written in the memory 15 and controls the LED chips 8 to have the same light emission amount.

FIG. 8 is a diagram showing the sensor output when a white original is read by the linear light source device 6 of the fourth embodiment. The solid line in the figure shows the sensor output when the LED drive control circuit 11 is activated. And the broken line is the sensor output when the LED drive control circuit 11 is not used.

According to the fourth embodiment, each LE is stored in the memory 15.
Since the lighting condition of the D chip 8 is written in advance, if the lighting condition is rewritten so that the sensor output becomes uniform every time the image is read a desired number of times, the light emission amount of the LED chip 8 changes with time, or the optical system It is possible to correct the change in the irradiation light amount due to dirt and the like.

Embodiment 5 FIG. FIG. 9 is a perspective view of a linear light source device according to a fifth embodiment of the present invention, in which the memory 15 of the fourth embodiment is added to the linear light source device of the second embodiment. 9, the same reference numerals as those in FIGS. 3 and 7 denote the same or corresponding portions.

The operations of the LED drive control circuit 11 and the memory 15 of the fifth embodiment are the same as those of the LED drive control circuit 1 of the fourth embodiment.
1 and the operation of the memory 15 are similar to those of the condenser lens 1
Since the function of 2 is the same as the function of the condenser lens 12 of the second embodiment, the description thereof will be omitted.

According to the fifth embodiment, a linear light source device having the effects of the second embodiment and the effects of the fourth embodiment can be obtained.

Embodiment 6 FIG. FIG. 10 is a perspective view of a linear light source device according to a sixth embodiment of the present invention.
The memory 15 of the fourth embodiment is added. 10, the same reference numerals as those in FIGS. 5 and 7 denote the same or corresponding portions.

The operation of the LED drive control circuit 11 and the memory 15 of the sixth embodiment is the same as that of the LED drive control circuit 1 of the fourth embodiment.
1 and the operation of the memory 15 and the operation of the concave mirror 14 is the same as that of the concave mirror 14 of the third embodiment.
Description is omitted.

According to the sixth embodiment, a linear light source device having the effects of the third embodiment and the effects of the fourth embodiment can be obtained.

Embodiment 7 FIG. FIG. 11 is a diagram showing a linear light source device according to a seventh embodiment of the present invention. In the seventh embodiment, a light source moving means is added to the conventional linear light source device 6. FIG.
In FIG. 33, the same reference numerals as those in FIGS. 33 and 34 denote the same or corresponding portions, and 16 denotes a light source moving member,
Reference numeral 17 denotes a driving circuit, and the light source moving member 16 and the driving circuit 17 constitute a light source moving means. A large number of LED chips 8 are arranged in a line on the upper surface of the light source moving member 16 to form the linear light source 6, and the driving circuit 17 causes the LED chips to be read within one line reading time by an image sensor (not shown). The LED chip 8 is driven so as to move a distance of about half of the arrangement interval of 8 or to oscillate with an amplitude of about half of the arrangement interval of the LED chips 8 in a period sufficiently shorter than the reading time of one line within the reading time.

FIG. 12 is a diagram showing the intensity distribution of the irradiation light on the reading line in the seventh embodiment, and FIG. 13 is a diagram showing the sensor output in the seventh embodiment.

Next, the operation will be described. Each LED chip 8 is driven and controlled by the LED drive circuit 9 and emits light of substantially the same light amount. As for the intensity distribution of the emitted light on the reading line, the intensity corresponding to the arrangement interval of the LED chips 8 is generated as shown by the solid line in FIG. When the light source moving member 16 is driven by the drive circuit 17 and moved by a distance approximately half the arrangement interval of the LED chips 8, the intensity distribution of the irradiation light is almost equal to the arrangement interval of the LED chips 8 as shown by the broken line in FIG. Since the positions are shifted by a half distance and the positions of strength and weakness are superposed on each other, a uniform strength distribution is obtained.
A uniform sensor output is obtained as shown in FIG.

Embodiment 8 FIG. FIG. 14 is a diagram showing a linear light source device of an eighth embodiment of the present invention. In the eighth embodiment, the LED drive control circuit 11 of the first embodiment is added to the linear light source device of the seventh embodiment. is there. In FIG. 14, FIG. 1 and FIG.
The same reference numerals denote the same or corresponding parts.

FIG. 15 is a diagram showing the intensity distribution of the irradiation light on the reading line in the eighth embodiment, and FIG. 16 is a diagram showing the sensor output in the eighth embodiment.

Since the operations of the LED drive control circuit 11 and the light source moving means of the eighth embodiment are the same as the operations of the LED drive control circuit 11 of the fourth embodiment and the light source moving means of the seventh embodiment, detailed operations will be described. Although the description is omitted, when the LED drive control circuit 11 and the light source moving means are not operated, the output at both ends is low as shown by the alternate long and short dash line in FIG. 15, and the sensor output due to variations in the output of the LED chip 8 is generated. However, when the LED drive control circuit 11 is actuated, the intensity distribution becomes substantially flat as shown by the solid line, and the light source moving means moves the LED chips 8 by a distance which is about half the arrangement interval. A more uniform intensity distribution is obtained, and a uniform sensor output is obtained as shown in FIG.

Embodiment 9 FIG. FIG. 17 is a perspective view of a linear light source device according to a ninth embodiment of the present invention.
The condenser lens 12 of the second embodiment is added. FIG.
7, the same reference numerals as those in FIGS. 3 and 14 indicate the same or corresponding portions.

FIG. 18 is a diagram showing the optical function of the ninth embodiment. FIG. 18 (a) shows the intensity distribution of the irradiation light on the reading line, and FIG. 18 (b) shows the reading line. It is the figure which showed the intensity distribution of the irradiation light of the direction orthogonal to.

The operations of the LED drive control circuit 11 and the light source moving means of the ninth embodiment are similar to those of the LED drive control circuit 11 and the light source moving means of the eighth embodiment, and the action of the condenser lens 12 is the same as that of the embodiment. Since the operation is the same as that of the second condensing lens 12, the description thereof will be omitted.

According to the ninth embodiment, the second embodiment and the eighth embodiment.
A linear light source device having the above effect can be obtained.

Embodiment 10 FIG. FIG. 19 shows a first embodiment of the present invention.
In the perspective view of the linear light source device of No. 0, the concave mirror 14 of Example 3 is added to the linear light source device of Example 8. In the figure, the same reference numerals as those in FIGS. 5 and 14 indicate the same or corresponding portions.

FIG. 20 is a diagram showing the optical action of the ninth embodiment. FIG. 20 (a) shows the intensity distribution of the irradiation light on the reading line, and FIG. 20 (b) shows the reading line. It is the figure which showed the intensity distribution of the irradiation light of the direction orthogonal to.

The operations of the LED drive control circuit 11 and the light source moving means of the tenth embodiment are similar to those of the LED drive control circuit 11 and the light source moving means of the eighth embodiment, and the operation of the concave mirror 14 is the same as that of the third embodiment. Since the operation is the same as that of the concave mirror 14, description thereof will be omitted.

According to the tenth embodiment, a linear light source device having the effects of the third and eighth embodiments can be obtained.

Embodiment 11 FIG. FIG. 21 shows the first embodiment of the present invention.
1 is a diagram showing the linear light source device of Example 1, in which the memory circuit 15 of Example 4 is added to the linear light source device of Example 8. FIG.
In the figure, the same reference numerals as those in FIGS. 7 and 14 indicate the same or corresponding portions.

FIG. 22 is a diagram showing the intensity distribution of the irradiation light of the eleventh embodiment, and FIG. 23 is a diagram showing the sensor output.

The operations of the LED drive control circuit 11 and the light source moving means of the eleventh embodiment are similar to those of the LED drive control circuit 11 and the light source moving means of the eighth embodiment, and the operation of the memory circuit 15 is the same as that of the fourth embodiment. Since the operation is the same as that of the memory circuit 15 of, the description thereof will be omitted.

According to the eleventh embodiment, a linear light source device having the effects of the fourth and eighth embodiments can be obtained.

Embodiment 12 FIG. FIG. 24 shows the first embodiment of the present invention.
34 is a view showing the linear light source device 2 and the same reference numerals as those in FIG. 34 denote the same or corresponding portions, and 18 denotes a concave wiring substrate, both ends of which approach a reading line of a document (not shown). A large number of LED chips 8 are arranged on a straight line formed in a concave surface and parallel to the reading line.

FIG. 25 (a) is a plan view of the twelfth embodiment, FIG. 25 (b) is a diagram showing the intensity distribution of the irradiation light on the reading line, and FIG. 26 is a diagram showing the sensor output.

Next, the operation will be described. The LED chip 8 is supplied with power by the LED drive circuit 9 and emits light. Irradiation surface 1 of light emitted from each LED chip 8
As shown in FIG. 25 (b), the intensity distribution on No. 3 is such that the intensity of the irradiation light becomes large because both ends of the reading line are closer to the irradiation surface 13 than the central part. However, the irradiation surface 13 that combines the light output from each LED chip 8
The upper intensity distribution is uniform in the reading line direction because there is no light from the outside, and therefore the sensor output is uniform as shown in FIG.

Example 13 FIG. 27 shows the first embodiment of the present invention.
3 is a perspective view of the linear light source device of Example 3, in which the condenser lens of Example 2 is added to the linear light source device of Example 12. FIG. In the figure, the same reference numerals as those in FIGS. 3 and 24 denote the same or corresponding portions.

FIG. 28 is a diagram showing the optical action of the thirteenth embodiment. FIG. 27 (a) shows the intensity distribution of irradiation light on the reading line, and FIG. 27 (b) shows the reading line. It is the figure which showed the intensity distribution of the irradiation light of the direction orthogonal to.

The operation of the linear light source 6 and the operation of the condenser lens 12 of the thirteenth embodiment are the same as the operation of the linear light source 6 of the twelfth embodiment and the operation of the condenser lens 12 of the second embodiment. Omit it.

According to the thirteenth embodiment, a linear light source device having the effects of the twelfth embodiment and the second embodiment can be obtained.

Example 14 FIG. 29 shows the first embodiment of the present invention.
4 is a perspective view of the linear light source device of FIG. 4, and the same reference numerals as those in FIGS. 5 and 24 denote the same or corresponding portions. In Example 14, the linear light source device 6 of Example 3 was replaced with Example 12.
The linear light source device 6 of FIG.

FIG. 30 is a diagram showing the optical function of the fourteenth embodiment, FIG. 30 (a) is a diagram showing the intensity distribution of the irradiation light on the reading line, and FIG. 30 (b) is orthogonal to the reading line. It is the figure which showed the intensity distribution of the irradiation light of the direction.

Since the operation of the linear light source 6 and the operation of the concave mirror 14 of the fourteenth embodiment are the same as the operation of the linear light source 6 of the twelfth embodiment and the concave mirror 14 of the third embodiment, the description thereof will be omitted.

According to the fourteenth embodiment, a linear light source device having the effects of the twelfth embodiment and the third embodiment can be obtained.

[0073]

According to the first aspect of the present invention, since the lighting drive control means controls the amount of light emitted from each point light source of the linear light source to be the same, the irradiation light on the reading line is controlled. There is an effect that a linear light source device having a uniform intensity can be obtained.

According to the second aspect of the present invention, the lighting drive control means reads the lighting conditions of the plurality of point light emission sources stored in the storage means and controls the light emission amount of the plurality of point light emission sources. The linear light source device has an effect that the irradiation light intensity on the reading line becomes uniform, and a change in the irradiation light amount of the LED chip with time or a change in the irradiation light amount due to dirt of the optical system or the like can be corrected.

According to the third aspect of the present invention, the linear light source moving means moves the linear light source in the direction of the reading line by a distance approximately half the arrangement interval of the LED chips.
There is an effect that a linear light source device in which the irradiation light intensity on the reading line is uniform can be obtained.

According to the fourth aspect of the present invention, the lighting drive control means controls so that the amount of light emitted from each point light source becomes the same, and the linear light source moving means reads the linear light source. Since the linear light sources are moved in the line direction by a distance that is half the arrangement interval of the linear light sources, there is an effect that a linear light source device in which the irradiation light intensity on the reading line is uniform is obtained.

According to the fifth aspect of the invention, the lighting drive control means controls so that the light emission amounts of the respective point light emission sources become equal according to the lighting conditions read from the storage means, and the linear light source moving means: Since the linear light source is moved in the reading line direction by a distance which is half the arrangement interval of the linear light sources, there is an effect that a linear light source device with uniform irradiation light intensity on the reading line can be obtained.

According to the sixth aspect of the present invention, the plurality of point light sources arranged in a line on the surface of the support substrate formed in the concave surface have a peripheral portion close to the irradiation surface and a central portion. Since they are arranged far away from each other, there is an effect that a linear light source device in which the irradiation light intensity on the reading line is uniform can be obtained.

According to the invention of claim 7, the condenser lens comprises:
Since the linear light generated by the linear light source at the first focus is focused inward of the linear irradiation light and at the second focus in the direction orthogonal to the reading line, There is an effect that a uniform linear light source device having a high irradiation light intensity can be obtained.

According to the eighth aspect of the present invention, the concave mirror bends the linear light generated by the linear light source and condenses the linear irradiation light toward the inner side at the first focal point, and the second focal point. Since the light is focused in the direction orthogonal to the reading line, the linear light source device that has a large irradiation light intensity on the reading line, is uniform, and can be downsized is obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a small image scanner using a linear light source device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a sensor output of the linear light source device according to the first embodiment.

FIG. 3 is a perspective view showing a linear light source device according to Embodiment 2 of the present invention.

FIG. 4 is a diagram showing an optical effect of the second embodiment.

FIG. 5 is a perspective view showing a linear light source device according to a third embodiment of the invention.

FIG. 6 is a diagram showing an optical action and an intensity distribution of irradiation light of Example 3.

FIG. 7 is a diagram showing a linear light source device according to Embodiment 4 of the present invention.

FIG. 8 is a diagram showing a sensor output of the linear light source device according to the fourth embodiment.

FIG. 9 is a perspective view showing a linear light source device according to Embodiment 5 of the present invention.

FIG. 10 is a perspective view showing a linear light source device of Embodiment 6 of the present invention.

FIG. 11 is a diagram showing a linear light source device according to Embodiment 7 of the present invention.

FIG. 12 is a diagram showing an intensity distribution of irradiation light of Example 7.

FIG. 13 is a diagram showing a sensor output according to the seventh embodiment.

FIG. 14 is a diagram showing a linear light source device according to an eighth embodiment of the present invention.

FIG. 15 is a diagram showing an intensity distribution of irradiation light of Example 8.

FIG. 16 is a diagram showing a sensor output according to the eighth embodiment.

FIG. 17 is a perspective view showing a linear light source device of Example 9 of the invention.

FIG. 18 is a diagram showing an optical function and an intensity distribution of irradiation light of Example 9.

FIG. 19 is a perspective view showing a linear light source device according to Embodiment 10 of the present invention.

FIG. 20 is a diagram showing an optical action and intensity distribution of irradiation light of Example 10.

FIG. 21 is a diagram showing a linear light source device of Embodiment 11 of the present invention.

22 is a diagram showing an intensity distribution of irradiation light in Example 11. FIG.

FIG. 23 is a diagram showing the sensor output of the eleventh embodiment.

FIG. 24 is a diagram showing a linear light source device according to Embodiment 12 of the present invention.

FIG. 25 is a diagram showing an intensity distribution of irradiation light of Example 12.

FIG. 26 is a diagram showing a sensor output of the twelfth embodiment.

FIG. 27 is a perspective view showing a linear light source device of Embodiment 13 of the present invention.

FIG. 28 is a diagram showing an optical action and intensity distribution of irradiation light of Example 13.

FIG. 29 is a perspective view showing a linear light source device of Embodiment 14 of the present invention.

FIG. 30 is a diagram showing the optical action and intensity distribution of irradiation light of Example 14.

FIG. 31 is a diagram showing a configuration of a small image scanner using a conventional cold cathode fluorescent lamp.

FIG. 32 is a diagram showing a sensor output of a conventional small image scanner.

FIG. 33 is a diagram showing a configuration of a contact image scanner using a conventional linear light source device.

FIG. 34 is a perspective view of a linear light source device using a light emitting diode (LED) chip.

FIG. 35 is a diagram showing a sensor output of a conventional contact image scanner.

[Explanation of symbols]

2 originals, 3 reflecting mirrors, 4 imaging lenses, 5 image sensors, 6 linear light sources, 7 wiring boards, 8 LED chips (point light sources), 9 LED drive circuits, 11 LED drive control circuits (lighting control means), 12 condenser lens, 13
Irradiation surface, 14 concave mirror, 15 memory, 16 light source moving member, 17 drive circuit, 18 concave wiring board.

Front Page Continuation (72) Inventor Koichi Noguchi 1 Nagabakyo Baba Institute, Video System Development Laboratory (72) Inventor Naoshi Maeda Nagaokakyo Baba Institute 1 Mitsubishi Electric Corporation In the laboratory

Claims (8)

[Claims] 1. A light source device for irradiating a document surface with thin linear light, wherein a plurality of point-like light emitting sources are linearly arranged on the surface of a wiring board; And a lighting drive control means for adjusting at least one of the light emission intensity and the light emission time of each point light source so that the amount of light emitted from each point light source of the linear light source becomes the same. Linear light source device. 2. A storage means for storing lighting conditions represented by each emission intensity or each emission intensity ratio of a plurality of point emission sources, or each emission time or each emission time ratio is provided. The linear light source device according to claim 1, wherein the lighting drive control means is configured to drive a plurality of point emission sources. 3. The linear light source device according to claim 1, further comprising light source moving means for moving the linear light source in a longitudinal direction. 4. A lighting drive control means for adjusting at least one of the light emission intensity and the light emission time of each point light source so that the amount of light emitted from each point light source becomes the same. The linear light source device according to claim 3. 5. The lighting drive control means includes a storage means for storing lighting conditions represented by each light emission intensity or each light emission intensity ratio of the plurality of point light emission sources, or each light emission time or each light emission time ratio. The linear light source device according to claim 4, wherein the linear light source device is provided. 6. A light source device for irradiating a document surface with a thin linear light, wherein the linear light source is formed with a concave surface in a longitudinal direction facing the document surface, and the wiring board. 1. A linear light source device comprising a plurality of point-like light emitting sources linearly arranged in the longitudinal direction on the plane. 7. A first focal point for converging light generated by a linear light source inward of the linear irradiation light, and a second focal point for converging light in the direction orthogonal to the direction of the linear irradiation light. 5. A condensing lens having a focal point is provided.
6. The linear light source device according to any one of 6 above. 8. A first focal point for converging the light generated by the linear light source inward of the linear irradiation light, and a second focal point for converging light in the direction orthogonal to the direction of the linear irradiation light. The linear light source device according to claim 1, further comprising a concave mirror having a focal point.