JPH04183062A - Image reader - Google Patents

Abstract

PURPOSE:To eliminate unreadable colors without increasing energy consumption by successively switching and turning on the light sources of plural colors during the period of reading one line. CONSTITUTION:The read cycle for one main scanning line is divided into two and in one cycle, the light source of two colors such as G (green) and R (red) are successively turned on by a turn-on control circuit 9. Then, original reflecting beams caused by turning on the respective light sources are stored in a line sensor 7. In this way, the two kinds of light sources are successively turned on so as to read one line, and they are not simultaneously turned on. Thus, although an output level is a little lower, the unsensible colors can be made minimum without increasing energy consumption.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an image reading device.

[Prior Art] Generally, in a color image reading device that has three color light sources of R (red), (green), and B (blue) and reads a color document by sequentially lighting them, it converts a color document into monochrome. When reading information, a G (green) light source is used instead, or all three color light sources are turned on and read as a white light source.

[Problems to be Solved by the Invention] Generally, when reading monochrome information, it is required to read all color information on a color document without omitting it. However, when reading with a G (green) light source, the unreadable color, ie, the dropout color, is pale yellow to pale blue, and has a drawback that it is somewhat wide. Even if the other color R (red) is used, a lighter red color cannot be read, and even if B (blue) is used, a lighter blue color cannot be read. Furthermore, if all of the R/G/83 color light sources are turned on, it would be ideal to be able to read all the colors, but since the three light sources are turned on at the same time, the power consumption would be tripled.

This invention was made in view of the above circumstances, and its purpose is to minimize dropout colors, which are colors that cannot be read, when obtaining a monochrome image reading signal from a color image. (Another object of the present invention is to provide an image reading device that can read multiple colors without increasing power consumption due to lighting of a light source beyond one color.)

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a plurality of color light sources, a lighting means for sequentially lighting each of the plurality of color light sources within one line reading period, and a light source for each of the plurality of colors. The present invention is characterized in that it includes a line sensor that accumulates the reflected light of the light source light from the document every one line reading cycle.

[Function] According to the present invention, multiple light sources are not turned on at the same time, but are turned on sequentially, so power consumption does not increase (
It becomes possible to reduce the dropout color.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a color image reading device having a typical R/G/83 color light source. In the same figure, three color light sources (R, G, B
The reflected light 5 from the original 2 is bent by the first mirror 3 and the second/third mirror 4, and is imaged on the line sensor 7 via the lens 6. 1st
The mirror is integrated with three color light sources to constitute the first mirror unit 8, and for example, in the figure, the mirror scans the original 2 while moving from right to left (sub-scan) (main scan). As the first mirror unit 8 moves, the second mirror unit consisting of the second/third mirror 4 also moves to the first mirror unit so as to keep the optical path length constant.
The mirror unit 8 is moved by a distance equal to the moving distance.

1-1 in Figure 2 shows the reading cycle T of one main scanning line, and normally when reading in a single color, 1-1 in Figure 2
Continue to turn on the light source as shown in . In the present invention, the second
As shown in Figure 1-2, the reading cycle for one line is divided into two, and two color light sources are used within one cycle.
The light sources of two colors, green (green) and red (R), are sequentially turned on by a lighting control circuit 9, and the line sensor 7 accumulates the light reflected from the original by each light source being turned on. In this way, two types of light sources are turned on in sequence to read one line, and since they are not turned on at the same time, there is no increase in power consumption (although the output level is lower, it is possible to minimize blind colors). The tone of the two colors and the lighting period do not need to be the same as shown in the figure, and may be changed as needed.Also, 1-
As shown in FIG. 3, three types of light sources may be sequentially switched and turned on.

[Effects of the Invention] As explained above, according to the present invention, the light sources of multiple colors are sequentially switched and turned on during the reading period of one line. Can be illuminated with a light source to minimize or eliminate unreadable colors.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an image reading device according to an embodiment of the present invention using light sources of R/G/83 colors, and Fig. 2 is a time chart for explaining lighting control of a plurality of light sources in the embodiment. FIG. 1... Original table glass, 2... Color original, 3... First mirror, 4... Second... 3rd mirror, 5... Reflected light, 6... Lens, 7... Line sensor, 8... First mirror unit. (/ Figure 1 Figure 2

Claims (1)

[Claims] 1) A plurality of color light sources, a lighting means for sequentially lighting each of the plurality of color light sources within one line reading period, and accumulating the reflected light from the document of each of the light source lights for each one line reading period. An image reading device characterized by comprising a line sensor.