JPH01265661A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To increase the luminous quantity of an LED array and to eliminate a dropout color by providing plural colored LED elements on an LED array used for a solid-state image pickup element. CONSTITUTION:LED 106 for red light and LED 107 for yellow light are arranged alternately in the ratio of 1:3 on the LED array used for a solid-state image pickup element and the interval of LED elements 105 is selected as 1mm or below. Through the constitution above, the luminous quantity is more than double of a conventional device and since two kinds of lights (yellow and red) radiate the original face, no dropout color exists. That is, the red original such as a pink being unable to read by the red LED 106 is lighted by the yellow LED 107 and conversely, an yellow original is lighted by the red LED 106.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a document reading device used in electronic equipment such as a facsimile machine or a copying machine, which is equipped with a light source and a same-magnification imaging element in a same-magnification image sensor. The present invention relates to a mounting structure for a solid-state imaging device.

[Prior Art] Conventionally, a solid-state imaging device in which a 1-magnification image sensor is equipped with a light source and a 1-magnification image forming element generally uses an LED array as a light source; The optical system was formed using a converging optical lens array or a fiber array plate.

An LED array consists of multiple high-brightness light emitting diodes lined up.
It is constructed in combination with a condensing rod-shaped lens, and is small and has a long lifespan, requiring almost no maintenance.

[Problems to be Solved by the Invention] However, conventional lighting using LED arrays has the following problems. (1) Because the light is monochromatic, there are colors that cannot be read (dropout colors). (
2) Insufficient light. The reading density of the same-magnification image sensor is high, and as the reading speed becomes faster, a brighter light source is required.

Therefore, the present invention is intended to solve such problems.
The purpose is to increase the light intensity of the LED array, eliminate dropout colors, and even enable color original r4 reading.

[Means for Solving the Problems] The present invention is intended to solve the above-mentioned problems, and the solid-state imaging device of the present invention includes (1) a 1-magnification imaging element and a 1-magnification imaging element; In a solid-state imaging device equipped with a light source using an LED array, the LED
It is characterized by mounting LED elements of a plurality of emitting colors on an array. Furthermore, (2) the LED element spacing on the LED array is set to 1 mm or less, and a plurality of LED elements of a single luminescent color are mounted on the LED array.

Hereinafter, the details of the present invention will be shown by examples.

[Example] FIG. 1(a) is a front view showing the structure of an LED array used in a solid-state imaging device in an example of the present invention.
FIG. 1(b) is a side view thereof.

LED 106 with red emission color and LED 107 with yellow emission color
are arranged alternately at a ratio of 1:3, with an LED element spacing of 105
is 1 mm or less. With such a structure, the amount of light is equal to that of conventional credit sales. Furthermore, since the document surface is illuminated with two types of light, red and yellow, there is no dropout color. In other words, the red LED
The vermilion-red manuscript, which could not be read with the scanner, is illuminated by yellow LEDs. Conversely, a yellow original is illuminated by a red LED. Currently red LE
Since the light amount of D is approximately three times that of the yellow LED, the mounting density of both is made inversely proportional to the light amount ratio.

Furthermore, a monochrome LED can also be used when dropout color is not a problem, such as when only a monochrome original is to be read.

FIG. 3(a) is a front view showing the structure of an LED array in another embodiment of the present invention, and FIG. 3(b) is a side view thereof. 3 red LEDs parallel to the longitudinal direction of the LED array
06 row, a blue LED 308th row, and a green LED 309 row.

With such a structure, it can also be used as a light source for a light source switching type color reading device.

Conventional light sources for such color reading devices include, for example, "IEICE Technical Research Report ED87-38.
As shown in Figure 2, two cold cathode tubes were placed on one side of the gradient index lens array of the equal-magnification imaging system as red and blue light sources, and a fluorescent panel was placed on the other side as a green light source.

However, compared to using completely different light sources side by side to obtain different emission colors, an LED array like this, in which LEDs of multiple emission colors are configured on the same substrate, is very advantageous in terms of space. be. Furthermore, compared to the case where LEDs are arranged in a line, it is possible to increase the mounting density for each color by up to three times, and it is possible to suppress variations in the amount of light. The LED array is usually used in combination with the rod-shaped lens 303 for condensing light, but when the LED is located at the focal position of the rod-shaped condensing lens 303, the light condensing efficiency is naturally good, and the deviation from the focal position is reduced. The higher the number, the worse the efficiency becomes, so the positions of the red and green LEDs in FIG. 3 seem inappropriate at first glance. However, L
The amount of light in the ED decreases in the order of red, green, and blue, so
Arranging the blue LEDs 308 at the focal position of the condensing rod-shaped lens and arranging them so that the deviation from the focal position increases in the order of red and green is the same as changing the mounting density to balance the amount of light of each color. It is very useful.

[Effects of the Invention] As described above, according to the present invention, LED elements of a plurality of emitting colors are mounted on an LED array used in a solid-state imaging device, so the amount of light is more than doubled compared to the conventional one, and it is possible to It has the effect of being able to be read regardless of color. Furthermore, it has the advantage that it can also be used as a light source switching type light source for reading color originals.

[Brief explanation of the drawing]

FIG. 1(a) is a front view showing an embodiment of the LED array of the solid-state imaging device of the present invention, and FIG. 1(b) is a front view of the LED array of the solid-state imaging device of the present invention.
FIG. 3 is a side view of the array. FIG. 2 is a front view of an LED array of a conventional solid-state imaging device, FIG. 3(a) is a front view showing another embodiment of the LED array of a solid-state imaging device of the present invention, and FIG. FIG. 3 is a side view of the LED array. Applicant: Seiko Epson Co., Ltd. Representative Patent Attorney Masayoshi Ueyanagi (and 1 other person)

Claims (2)

[Claims] (1) In a solid-state imaging device including a 1x imaging element, a 1x imaging element, and a light source using an LED array, the LED
A solid-state imaging device characterized by mounting LED elements of a plurality of emission colors on an array. (2) The spacing between LED elements on the LED array should be 1 mm or less, and multiple or single LEDs of emitting color should be placed on the LED array.
2. The solid-state imaging device according to claim 1, characterized in that a D element is mounted.