JPS63240167A - Light source device - Google Patents

Abstract

PURPOSE:To read full color information and to erase a designated color easily by arranging plural light emitting elements with different lighting wavelength on a line at a prescribed interval and selecting at least one kind or over of the light emitting element of the same wavelength among the plural light emitting elements to light them. CONSTITUTION:Green or red LED groups 1, 2 with different wavelengths are arranged on a line as LEDs 11-13, LEDs 21-23. The groups 1, 2 are selected to have wide directivity close to nondirectiveity and clipped by light reflecting members 3, 4, then only one LED group is lighted on lines apart from a distance (d) to apply uniform lighting. When all pieces of information are read, the LED groups 1, 2 are lighted, green image information is radiated from the group 2, red picture information is radiated from the group 1 and other colors are radiated from the groups 1, 2, and they are read by a sensor 5. When a designated color, e.g., green color is erased, the group 1 is lighted and the group 2 is not lighted to read the color information other than the designated color and the image information of the designated color (green) is erased.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a light source device used for exposing a document in an image reading device, and in particular to a light source device used for a device with a wide image reading width such as an electronic blackboard. Regarding equipment.

(Prior Art) Conventionally, as this type of light source device, in addition to fluorescent lamps and cold cathode discharge tubes, a single type of LED row or LED array has been used.

(Problems to be Solved by the Invention) However, when applying the light source device in the conventional example to an electronic whiteboard device, since many marker colors are used in the electronic whiteboard device, it is difficult to use a single color. An image reading device using a light source having a wavelength or a wavelength distribution similar thereto has a problem in that it is unable to read a large number of marker colors.

In addition, with a light source device consisting of a fluorescent lamp or cold cathode discharge tube, it is possible to read a large number of marker colors by using white light, but when erasing specified colors, a specified filter is required. There was a problem.

Therefore, the present invention was made to solve the above-mentioned problems of the conventional example, and its purpose is to make it possible to read all color information and to erase designated colors without using a filter. The object of the present invention is to provide a light source device.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, a plurality of light emitting elements having different emission wavelengths are arranged at predetermined intervals and on the same line, and the plurality of light emitting elements are arranged on the same line. It is configured such that at least one type of light emitting elements having the same wavelength can be selected from among the elements and turned on.

(Function) In the present invention having the above configuration, all color information can be read by selecting at least one type of light emitting element having the same wavelength from among a plurality of light emitting elements having different emission wavelengths and enabling them to be lit. In some cases, all of the light emitting elements are lit,
When erasing a predetermined color, only the light emitting elements of the corresponding wavelength need to be turned on.

(Embodiment) The present invention will be explained below based on the illustrated embodiment. In FIG.
This is a group of LEDs (light emitting diodes) as a group of light emitting elements of red), and the LED groups 1 and 2, each having the same wavelength, are arranged at an interval S, with LEDs 1+, 13, 2+ on the same line.
They are arranged at an angle of ~23°. Here, LED group 1,
If LED 2 is selected to have wide directivity close to omnidirectionality and sandwiched between light reflecting members 3 and 4 as shown in Fig. 2, ripples will occur on a line separated by a distance d with only one LED group lit. Uniform illumination is possible with just a few percent. Note that the relationship between the interval S and the distance d is d/s→0.6.

Further, in FIG. 2, reference numeral 6 denotes an original, and the sensor 5 reads the transmitted light of this original.

Here, FIG. 3 shows the relationship between the interval S and the distance d.

To explain in more detail based on FIG. 4, the LED group 1 or 2 is arranged at the position PitP2 shown in FIG. is obtained by adding the light from both two light sources, and the third
Considering only the light in the figure, the ripple becomes minimum when dls←0.7 due to the characteristic (a) shown in FIG. 4. However, if the omnidirectional light emitted three-dimensionally is focused two-dimensionally by two light reflecting members parallel to the light source, the fourth
The characteristic (b) shown in the figure is obtained, and the minimum ripple point is lower than that of characteristic (a), and the amount of ripple is also smaller. Incidentally, this means that the characteristic (a) is 1. The light from the light emitting point is 2.
The characteristic (b) attenuates inversely to the first power of the distance, whereas the characteristic (b) attenuates inversely to the first power of the distance. Therefore, the smaller the ripple minimum point (d/s), the more compact the device can be, and the more linear the light can be without loss from the light emitting point.

Incidentally, the light reflecting members 3 and 4 can be realized by forming members such as mirrors, metals, resins, etc. by surface treatment or coating. Further, although the light guide path is a free space, it may be filled with resin or the like. In this case, the opposing surfaces may be made of a resin that has been subjected to a surface treatment such as aluminum vapor deposition for internal reflection, and the inner surface of the surface-treated portion may be used as a reflective member.

In the above configuration, the color information reading operation will be explained. When reading all color information, LED groups 1 and 2
By lighting up the sensor 5, green image information is irradiated by the red LED group 2, red image information is irradiated by the green LED group 1, and images of other colors are irradiated by the tllNltLED#1.2. Read by

Next, when erasing the designated color, if the designated color is green, the LED DJJ1i of the same color is turned on, and the LED group 2 is not turned on, so that it becomes a green light source and color information other than the designated color is read. That is, the image information of green, which is the designated color, is erased. Similarly, when the specified color is red, L
By lighting up ED group 2 and not lighting up LED group 1, the color information of red, which is the designated color, is erased. Furthermore, by using a configuration having three or more types of LED groups, it becomes possible to erase three or more specified colors.

FIG. 5 is a schematic diagram showing a second embodiment of the light source device according to the present invention. In this embodiment, since the light emitted from the light reflecting members 13 and 14 is non-directional, the light The condensing rod lens 1 is placed in the same direction as the installation direction of the reflecting members 13 and 14.
7 is arranged to collect the light emitted from the light reflecting members 13 and 14. This condensing rod lens 17 may be a normal glass round rod.

FIG. 6 is a schematic diagram showing a third embodiment of the light source device according to the present invention, and in this embodiment, the light reflecting members 23 and 24 are
If they are arranged so as to spread toward the radiation end, the emitted light will be focused in the X direction, so even if the distance from the radiation end to the sensor 25 must be large, the reduction in light intensity due to the distance will be small.

FIG. 7 is a schematic diagram showing a fourth embodiment of the light source device according to the present invention. In this embodiment, the light reflecting members 33 and 34 have a curvature and the light guide path is bent by 90'. If the reflectance is high, characteristics similar to those of the first embodiment can be obtained, and the degree of freedom in arrangement inside the device is improved.

Next, FIG. 8 shows a fourth embodiment of the light source device according to the present invention. In this embodiment, an LED group 1 is provided.

This is the case where the arrangement pitch of 2 is changed, and the luminous efficiency.

When a large amount of current must flow due to the spectral characteristics of the sensor, the same current value can be obtained by increasing the number of sensors per unit length compared to the case where the sensors are arranged at the same pitch as in the above embodiment. be able to.

(Effects of the Invention) The light source device according to the present invention has the above-described configuration and operation, and has the advantage of being able to easily read all color information and erase designated colors.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of the light source device according to the present invention, FIG. 2 is a schematic diagram of the same embodiment, and FIGS. 3 and 4 are explanatory diagrams showing the operation of the same embodiment. Graph, FIG. 5 is a schematic diagram showing the second embodiment of the light source device according to the present invention, FIG.
The figure is a schematic diagram showing a third embodiment of the light source device according to the present invention, FIG. 7 is a schematic diagram showing a fourth embodiment of the light source device according to the present invention, and FIG. 8 is a schematic diagram showing a fourth embodiment of the light source device according to the present invention. It is an explanatory view showing a fifth example of. Explanation of symbols 1.2... LED group (light emitting element group) 3.4... Light reflecting member 5... Sensor 6... Original Figure 7 Figure 3 Figure 2 05'° Inclusion 5 Medical 011ko＼5 Figure 8

Claims (1)

[Claims] A plurality of light emitting elements having different emission wavelengths are arranged at predetermined intervals and on the same line, and at least one kind of light emitting element having the same wavelength can be selected from among the plurality of light emitting elements to light up. Light source device.