JPS62292069A - Color identification device - Google Patents

Abstract

PURPOSE:To execute color identification having high reliability especially to temperature and humidity by separating a monochromatic light from plural monochromatic light sources which are reflected or transmitted by the object to be identified into the corresponding monochromatic light component and identifying the color of the object to be identified by means of separation output. CONSTITUTION:A red LED5a is made pulse lighting by a drive circuit 10a and a green LED5b is made pulse lighting by a drive circuit 10b. The light beams are reflected by the original of the object to be identified and converted into an electric signal in a light receiving element 8. The output of the element 8 is separated into red component and green component in a switch circuit 12 and moreover integrally amplified in integration circuits 13a and 13b. Next it is converted into an amplitude signal by sample and hold circuits 14a and 14b and outputted to an external circuit (not shown in figure), so that the red component and the green component of the original can be read. Thus the color identification having high reliability especially to temperature and humidity can be executed.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a color identification device used for color identification of objects to be identified, such as color originals.

[Conventional technology]

2. Description of the Related Art Various types of color identification devices for objects to be identified, such as color originals, have been known. A typical reading method of a color original reading device, which is a type of color identification device, is shown in FIG. 2.

In the configuration diagram shown in FIG. 2, a lens 2 is placed in front of a light source 1 such as a halogen lamp, so that light from the light source 1 is focused on a document 3. A red light-receiving element 4a and a green light-receiving element 4b are placed near the original 3, and these red light-receiving elements 4a.

The red component signal and green component signal converted into electrical signals in step 4b are sent to a signal processing circuit (not shown).

Next, the operation of the conventional example shown in FIG. 2 will be explained.

Light from a light source 1 is focused by a lens 2 and irradiated onto a document 3. Then, the light reflected by the original 3 is received by the red light receiving element 4a and the green light receiving element 4b and converted into an electrical signal. Here, a red filter is attached to the surface of the red light receiving element 4a, so that the red component of the reflected light is detected.

Further, a green filter is attached to the surface of the green light receiving element 4b, so that only the green component of the reflected light is detected.

Therefore, if the document 3 is moved in such a state, the red and green components of characters, figures, etc. recorded on the document surface will be continuously detected, and a red signal and a green signal will be displayed according to the detected colors. It can be output from a signal processing circuit that does not.

(Problem to be Solved by the Invention) However, in the above-mentioned conventional device, a color filter is used in the light receiving element that detects the reflected light from the color document, and thereby monochromatic light such as red or green is detected respectively. As a result, there was a drawback that the reliability of the color filter was particularly low with respect to temperature and humidity. For this reason, there are disadvantages such as not being able to accurately detect colors, and sometimes having a short processing time, and this also applies to color identification devices other than color document reading devices.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the above-mentioned problems and provide a color identification device that has high reliability particularly with respect to temperature and humidity.

[Means for solving problems]

The present invention provides a color identification device for identifying the color of an object to be identified, such as a color original, in which a plurality of monochromatic light sources such as LEDs emitting light of different colors are provided, and driving means for lighting each in pulses is provided. The light reflected by or transmitted through the identification object is received by a light receiving element common to each monochromatic light without a color filter, etc., and the output signal of this light receiving element is separated into each monochromatic light component to perform color identification. This is a characteristic feature.

[Effect]

According to the present invention, since the color identification device is configured as described above, each monochromatic light source works to alternately send monochromatic light to an object to be identified by pulse lighting, and the light receiving element receives monochromatic light from an object to be identified. Therefore, the disadvantages of the prior art can be solved by separating the light components into monochromatic light components by the separating means.

(Example) Next, the present invention will be described in detail with reference to the drawings. 1st
The figure is a block diagram showing the circuit configuration of the color document reading device according to the embodiment, and FIG. 3 is a groove diagram showing the positional relationship between the light emitting and light receiving sections and the document in the above embodiment.

In FIG. 1, a red LED 5a as a red monochromatic light source
The light from the green LED 5b as a monochromatic green light source is focused by the corresponding lenses 2a and 2b, reflected by the document 3, and then converted into an electric signal by the light receiving element 8.

In FIG. 3, the red LED 5a is turned on by the driving circuit 'IOa. Further, the green LED 5b is pulse-lit by the drive circuit 10b. These lights are reflected by the original 3 and converted into electrical signals by the light receiving element 8. Here, the light receiving element 8 is an element that does not have a color filter, and its output is the sum of the outputs of the red component and the green component. This output is separated into a red component and a green component by a switch circuit 12, and an integrating circuit 13a is used to remove noise.
, 13b are integrated and amplified. Thereafter, the sample and hold circuits 14a and 14b output it as an amplitude signal.

Next, the operation of the above embodiment will be explained with reference to the signal waveform diagram in FIG. In Fig. 4, (a) is the red LED 5a.
(b> shows the waveform of the drive pulse (output pulse of the drive circuit 10b) that lights up the green LED 5b. (C) shows the waveform of the drive pulse (output pulse of the drive circuit 10b) that lights up the green LED 5b. As is clear from the figure, the output waveform is the sum of the output of the red component and the green component.When the output waveform of the light receiving element 8 is separated by the switch circuit 12, the red signal shown in (d> and(
The green signal shown in e) will be displayed.

When these signals are integrated and amplified by the integrating circuits 13a and 13b, a red signal waveform as shown in (f> and (Q)
The green signal waveform will be as shown in .

Further sampling by the sampling circuits 14a and 14b results in imaging width signals as shown in (h) and (i), which are output to an external circuit (not shown), allowing the red and green components of the color document to be read.

According to the method of the present invention, even if the red light source and the green light source have different emission powers, the sensor output can be easily made the same by changing the pulse lighting time. That is, for example, when the light emitting power of the green light source is lower than that of the red light source, FIG. 4(a).

J shown in (b), the lighting time TG of the sea urchin green light source may be lengthened, and the lighting time TR of the red light source may be shortened.

The present invention is not limited to the above embodiments, and various modifications are possible. For example, if three or more types of monochromatic light sources are used and these are alternately turned on by a drive circuit, it becomes possible to identify 32 or more types. Further, if an LED is used as a light source as in the embodiment, the life can be extended, but other monochromatic light sources may be used. Furthermore, it can be applied not only to detecting reflected light from an object to be identified (for example, a color original), but also to detecting and identifying transmitted light, and the object to be identified is limited to color originals. isn't it.

〔Effect of the invention〕

As explained above, according to the present invention, a plurality of monochromatic light sources are used as light sources of a color identification device, and the plurality of monochromatic light sources are alternately lit in pulses to emit light (reflected light or transmitted light) from an object to be identified. Since each monochromatic light is received by a common light-receiving element and converted into an electrical signal, there is no need to use a color filter for the light-receiving element, and reliability with respect to humidity and temperature can be significantly improved. It's effective.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram of an embodiment of the present invention, FIG. 2 is a configuration diagram of the vicinity of the light emitting and light receiving sections showing the method of a conventional device, and FIG. 3 is a configuration diagram of the vicinity of the light emitting and light receiving sections showing the method of the present invention. 4 are signal waveform diagrams of various parts of the circuit shown in FIG. 1. 3... Original, 4a... Red light receiving element, 4b... Green light receiving element, 5a... Red LED, 5b... Green L
ED, 8... Light receiving element, 10a... Red LED drive circuit, 10b... Green 1-ED drive circuit, 12.
...Switch circuit. Configuration diagram of conventional method Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A plurality of monochromatic light sources that emit different colored light, a driving means for alternately lighting the plurality of monochromatic light sources in pulses, and the plurality of monochromatic light sources that are reflected by or transmitted through an object to be identified. a light receiving means for receiving monochromatic light from the light receiving means and converting it into an electrical signal; and a separating means for separating the signal from the light receiving means into monochromatic light components corresponding to the plurality of monochromatic light sources, and according to the output from the separating means. A color identification device that identifies the color of the object to be identified. 2. The color identification device according to claim 1, wherein the monochromatic light source is an LED. 3. The color identification device according to claim 1, wherein the driving means varies the pulse lighting time depending on the light emission power of each monochromatic light source.