JPH04200063A - Light source device for image reading - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention uses a monochrome sensor to illuminate a document for a color image reading device that separates the colors into three primary colors and reads a color image. The present invention relates to a light source device.

[Prior Art] Conventionally, in a color image reading device such as a color scanner, when an image on a document surface is read using a monochrome sensor, the document is moved in one direction relative to the document, and its movement relative to the document is Along the scanning direction orthogonal to the direction, e.g. fluorescent lights.

An image reading light source device using a light source such as a neon tube sequentially irradiates line-shaped illumination light of each color, and reads the reflected light reflected by the document while scanning it in the scanning direction with a light receiver 11, for example, a CCD. As a result, the above-mentioned reading operation is sequentially repeated as the document moves, and the image on the document surface is separated into each color and read.

Such an image reading light source device is equipped with three light sources such as fluorescent lamps and neon tubes each configured to emit light of each color corresponding to the three primary colors of light.
By sequentially switching and controlling the light emitted from each light source by appropriate means, illumination light of each color is sequentially irradiated in a line at a predetermined position on the document surface.

[Problem to be solved by the invention]

However, in the image reading light source device configured in this way, it is necessary to provide a light source for each of the three primary colors of light, which increases the number of parts, increases the parts cost, and requires less installation space. As a result, there is a problem in that not only the image reading light source device but also the transposed image reading device becomes large.

In view of the above points, it is an object of the present invention to provide a light source device for color image reading which can be miniaturized as a whole and can reduce costs by emitting light of each color using one light source. It is an object.

[Means to solve the problem]

In order to achieve the object described in item E, the image reading light source device according to the present invention is arranged parallel to a light source such as a fluorescent lamp or a neon tube extending along the longitudinal direction. a liquid crystal shutter capable of emitting illumination light in a predetermined direction extending longitudinally from the light source; and a substantially hollow cylindrical reflecting member disposed to surround the light source from the circumferential direction except for a region of the liquid crystal shutter. , a hollow cylindrical rotary filter disposed outside the liquid crystal shutter and the reflective member so as to surround the light source, and comprising filter sections for each color divided so as to transmit the three primary color lights in the circumferential direction; and when each color filter section is brought to a predetermined position facing the reflective member by rotationally driving this rotary filter, the liquid crystal shutter is controlled to open in synchronization with this, The configuration is such that the three primary color lights transmitted through each color filter section can be sequentially irradiated onto the surface of the document whose image is to be read.

[For production]

According to this invention, when each color filter section is brought to a predetermined position facing the liquid crystal shutter by rotationally driving the rotary filter, the liquid crystal shutter is driven and opened in synchronization with this, and the light source is removed from the light source. The light emitted directly or through the liquid crystal display after being reflected by a reflecting member passes through only one of the color filter sections of the rotating filters, and
The light will be emitted to the outside.

As a result, a predetermined position on the document surface can be illuminated by light of only one color among the three primary colors of light transmitted through the color filter section, and as a result, the image information on the document surface related to the cough color is changed to monochrome. type of sensor.

By rotating the rotary filter in the same way, the image information on the document surface regarding each of the other colors can be similarly read by a monochrome type sensor, so that the color-separated image information regarding each of the three primary colors of light can be sequentially read. It will be read by the sensor.

Therefore, by appropriately processing and combining the image information of each color, it is possible to read the color image information on the document surface.In this way, the image information of each color can be obtained with one light source, so the number of parts is small and it is easy to read. It is constructed in a compact and compact manner, and the first stroke is reduced.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 shows an embodiment of the image reading light source device according to the present invention. A light source 11 such as a fluorescent lamp or a neon tube, and a liquid crystal shutter 12 arranged parallel to the light source 11.
The light source 11 except for the area of the liquid crystal shutter 12
A substantially hollow cylindrical reflecting member 13 is arranged to surround the light source 11 from the circumferential direction, and a hollow cylindrical reflecting member 13 is arranged to surround the light source 11 on the outside of the liquid crystal shutter 12 and the reflecting member 13. It is composed of a rotating filter 14.

The liquid crystal shutter 12 receives light directly from the light 1jitll or reflected by the reflecting member 13, and is controlled to open by a drive control circuit (not shown), thereby reducing glare in a predetermined direction extending in the oblong direction indicated by an arrow X. It can be emitted as illumination light in any direction.

The rotary filter 14 is configured by suitable means (not shown).
It is rotatably supported around a central axis, and in the case shown in the figure, a pulley portion 14a for rotational driving and a cooling fan 15 are integrally fixed to one end thereof. A heald 17 is wound around this pulley portion 14a between it and a drive shaft 16 such as a motor (not shown). Furthermore, the rotary filter 14 is composed of color filter sections 14b, 14c, and 14d that are divided in the circumferential direction so as to transmit the three primary color lights.For example, the color filter section 14b transmits the green light, Filter section 14c
is configured to transmit red light, and the color filter section 14d is configured to transmit blue light.

Here, the liquid crystal shutter 12 is rotationally driven around its central axis, so that each color filter section 14b, 14
c or 14d is brought to a predetermined position facing the liquid crystal display 12, the opening is controlled in synchronization with this, and as a result, each color filter section +4
The light that has passed through only one of b, 14c, and 14d is irradiated in a line extending in the scanning direction on the surface of the document whose image is to be read through a condensing lens (not shown) or the like. .

A thin film infrared filter (not shown) is formed on the surface of the liquid crystal shutter 12 to prevent infrared light of the light from the light source 11 from entering the sensor.

The embodiment of the present invention is constructed as described above, and the heald 1
By rotating the rotary filter 14 through the filter 7, each color filter section 14b of the rotary filter 14 is
, 14c or 14d are brought to a predetermined position facing the liquid crystal display 12. At this time, if the liquid crystal shutter 12 is driven and opened in synchronization with this, the light emitted from the light source 11 directly or through the liquid crystal shutter 12 after being reflected by the reflecting member 13 is filtered through the rotating filter. Among the 14 color filter sections 14b, 14c, or 14d, the light passes through only one of the color filter sections located at a predetermined position facing the liquid crystal shutter 12 (in the illustrated case, the color filter section 14b) and goes to the outside. The document surface can be illuminated by light of only one of the three primary colors of light transmitted through the color filter section 14b, green light in the illustrated case, through a condensing lens (not shown) or the like. Therefore, image information on the document surface regarding the color can be read by a monochrome type sensor (not shown).

Similarly, by rotating the rotary filter 14, the other color filter sections 14c or 14d are sequentially brought to a predetermined position facing the liquid crystal display 12, thereby providing image information on the document surface regarding each of the other colors. is the same as C
It can be read by a monochrome type sensor.

As a result, color-separated image information for each of the three primary colors of light is sequentially read by a monochrome sensor, and by appropriately processing and combining the image information of each color, a color image on the document surface is created. Information can be read.

Note that if the rotation of the rotary filter 14 is controlled so that the image is read while the rotary filter 14 is stationary, it is possible to read the images sequentially, and if the rotary filter 14 is rotated at high speed, If the image is read in a state where the image is read, line-sequential reading is possible. Furthermore, since the cooling fan 15 is integrally attached to the rotary filter 14,
Liquid crystal shafter 129 reflecting member 13 and rotating filter 1
The air around the light source 11 surrounded by the light source 11 is sucked out, and the heat from the light source 11 is released.

〔Effect of the invention〕

As described above, according to the present invention, when the rotary filter is rotationally driven and each color filter section is brought to a predetermined position facing the liquid crystal shutter, the liquid crystal shutter is driven and controlled in synchronization with this. When opened, the light emitted from the light source directly or through the liquid crystal shutter after being reflected by a reflective member passes through only one of the color filter parts of the rotary filter and exits to the outside. As a result, a predetermined position on the document surface can be illuminated by light of only one of the three primary colors of light transmitted through the color filter section. As a result, the image information on the document surface regarding the line color is read by a monochrome type sensor, and by rotating the rotary filter in the same way, the image information on the document surface regarding each sequential color is read by the monochrome type sensor. Since it can be read by a sensor, image information separated into colors for each of the three primary colors of light can be sequentially read by the sensor, and by appropriately processing and combining the image information of each color, the image information on the document surface can be read by a sensor. Color image information can be read.

Therefore, since image information of each color can be obtained with one light source, the number of parts is small, the structure can be simple and compact, and the cost can be reduced.

Thus, according to the present invention, by configuring one light source to emit light of each color, an extremely excellent light source device for color image reading is provided, which can be miniaturized as a whole and can reduce costs. provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing the structure of an embodiment of an image reading light source device according to the present invention, and FIG. 2 is a sectional view of a main part of the embodiment of FIG. 1. 10... Light source device for image reading; 11... Light ij!
t; 12...Liquid crystal display: 13...Reflection member;
14...Rotating filter; 14a-part of pulley;
14b, 14c. 14d... Color filter section; 15... Cooling fan; 16... Drive shaft: 17. Belt. Patent applicant: Stanley Electric Co., Ltd. Representative: Patent attorney Kodo Hirayama: Patent attorney Shintabe Okazaki: Patent attorney Tamotsu Kaizu 313
14c

Claims (1)

[Claims] (1) A light source such as a fluorescent lamp or a neon tube extending along the longitudinal direction, and a light source disposed parallel to the light source and emitting illumination light in a predetermined direction extending from the light source in the longitudinal direction. a liquid crystal shutter to obtain; a substantially hollow cylindrical reflecting member disposed to surround the light source from the circumferential direction except for an area of the liquid crystal shutter; It includes a hollow cylindrical rotary filter which is arranged so as to surround the filter and which is divided into filter parts for each color so as to transmit the three primary color lights in the circumferential direction, and by driving the rotary filter to rotate, When each color filter section is brought to a predetermined position facing the reflective member, the liquid crystal shutter is controlled to open in synchronization with this, so that the three primary color lights transmitted through each color filter section are sequentially read as an image. 1. A light source device for color image reading, characterized in that the light source device is capable of illuminating the surface of a document to be read.