JP2002254892A - Electronic blackboard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic blackboard which has a running reading unit which is equipped with a light receiving means for reading and a light source for illumination and runs along a board face and obtains an appropriate image which is read, regardless of a change in a quantity of outer light and is capable of limiting the emission level of the light source for illumination to a minimum required extent. SOLUTION: This electronic blackboard is equipped with a light receiving element 5 for detecting the quantity of outer light which detects the quantity of ambient outer light and adjusts the emission level of the light source 3 in accordance with the quantity of outer light detected by the light receiving element 5. Especially the quantity of outer light to the outer face of the light receiving element 5 is detected by installing the light receiving element 5 at the running reading unit 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic blackboard for reading an image on a board surface formed by writing with a marker or the like, and more particularly to a traveling board running along a board surface while holding a light receiving means for reading an image on the board surface. The present invention relates to an electronic blackboard having a reading unit.

[0002]

2. Description of the Related Art As shown in FIG. 7, in order to read an image on a board surface formed by writing with a marker, as shown in FIG.
An electronic blackboard having a configuration in which the travel reading unit 31 travels along the board surface 1a is known. Travel reading unit 3
1, a reading light receiving element for reading an image on the board surface 1a and an illuminating light source for irradiating the board surface 1a with light are held in a state facing the board surface 1a. It is supported in a state of being suspended from a bogie unit 34 running on a rail 33 provided at an upper end of a gantry 32 supporting a board, and is self-propelled in a left-right direction by a running motor built in the bogie unit 34 to read. Sometimes board 1
Starts running from the initial position (the position indicated by an imaginary line with the symbol S in the figure) shunted to the side of the board 1, and the position on the opposite side of the board 1 (the position with the symbol E in the diagram is indicated by the imaginary line). (The position shown), and the reading of the entire board surface 1a is completed. And
When reading again, the travel reading unit 31
This time, it runs in the opposite direction and returns to the initial position. Board 1
An operation panel 35 for setting various operations and a printing unit 36 for outputting a read image are provided below the printer.

In order to obtain an appropriate read image, it is desirable that such an electronic blackboard has a structure that is not affected by light that is not caused by the illumination light source, that is, external light such as indoor lighting or sunlight. On the other hand, if it is possible to simultaneously read an image drawn on a sheet or the like pasted on a board surface by a magnet or the like in addition to writing with a marker or the like, convenience can be improved. For this reason, conventionally, a sufficient gap has been secured between the traveling reading unit and the board surface in order to prevent interference between the traveling reading unit and the object stuck on the board surface. A flexible light-shielding member is provided to prevent external light from entering from a gap between the traveling reading unit and the board surface, while ensuring smooth traveling of the traveling reading unit.

[0004]

However, since the shapes of the objects to be attached on the board surface are various, there is a limit to blocking external light with the light shielding body. Further, the amount of external light greatly varies depending on the positional relationship between the lighting equipment and the window into which the sunlight shines, and furthermore, depending on the use environment such as the lighting state of the lighting equipment and the direction of the sunlight. For this reason, in order to stably obtain an appropriate read image that is not affected by changes in the external light amount, the illumination light source needs to have a sufficiently large light amount with respect to the assumed external light amount. There is an inconvenience that the cost is increased by employing a light source having high capacity and high durability.

[0005] The present invention has been devised to solve such problems of the prior art, and its main objects are as follows.
It is an object of the present invention to provide an electronic blackboard configured so that an appropriate read image can be obtained without being affected by a change in the amount of external light, and the amount of light emitted from an illuminating light source can be minimized. .

[0006]

According to the present invention, a light receiving means for reading an image on a board surface and an illuminating light source for irradiating the board surface with light are provided. An electronic blackboard having a traveling reading unit traveling along a board surface, comprising an external light amount detecting light receiving means for detecting a peripheral external light amount, and an illuminating light corresponding to the external light amount detected by the external light amount detecting light receiving means. The light emission amount of the light source can be adjusted.

According to this, an appropriate read image can be stably obtained without being affected by a change in the amount of external light.
Moreover, since the amount of light emitted from the illumination light source can be minimized, the power consumption of the illumination light source can be reduced, and the average value of the operating current can be reduced, so that the life of the illumination light source can be extended. In this case, it is possible to provide a light receiving means for detecting the external light amount on a board or a gantry. Is detectable, it is possible to cope with a case where the external light amount differs at a position on the board surface. In addition, if a light receiving element dedicated to external light amount detection is prepared, the external light amount at an appropriate portion can be detected without limiting the arrangement position.

The detection timing of the external light amount may be appropriately set according to the device configuration such as the position of the light receiving means for detecting the external light amount. For example, it is simple to perform the detection at the initial position of the traveling reading unit at the start of reading. However, the light emission amount may be adjusted in real time during the travel reading of the travel reading unit. Further, a configuration is also possible in which the amount of emitted light is adjusted by detecting the amount of external light at appropriate intervals while the traveling reading unit is traveling.

In the electronic blackboard, it is possible to adopt a configuration in which the external light amount detecting light receiving means is provided so as to be able to detect the external light amount on both sides opposite to each other across the reading light receiving means in the traveling reading unit. According to this, it is possible to cope with the case where the amount of external light incident from the gap between the traveling reading unit and the board differs in the incident direction, and this is effective, for example, when sunlight shines through a side window.

In the electronic blackboard, the light receiving means for reading is a plurality of light receiving elements arranged in the light receiving element unit, and a part of the light receiving element group of the light receiving element unit is used as a light receiving means for detecting an external light amount. It is possible to adopt a configuration in which the light receiving element is provided with light guiding means for selectively guiding light incident on the outer surface of the traveling reading unit. According to this, a light receiving element that is outside the reading range of the board surface and that is not substantially involved in reading is used for the purpose of detecting the external light amount. There is no need to provide them. In this case, the light guide means may be constituted by a mirror, but a light guide made of a light transmissive material such as an acrylic resin is preferable.

In the electronic blackboard, the illuminating light source can adjust the amount of light emission for each of a plurality of colors, and the light receiving means for detecting the amount of external light can detect the amount of external light for each of a plurality of colors. The light quantity can be adjusted for each color in accordance with the external light quantity for each color detected by the external light quantity detection light-receiving means. . According to this, when reading the image on the board surface in color, stable reading can be performed without being affected by the color tone of the external light.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a cross section of a travel reading unit as a first embodiment of an electronic blackboard according to the present invention. Here, a reading light-receiving element 2 for reading an image on the surface 1a of the board 1 and an illuminating light source 3 for irradiating light to the surface 1a of the board 1 are held by a traveling reading unit 4 traveling along the board 1. At the same time, an external light amount detecting light receiving element 5 for detecting the external light amount in the periphery is provided, and the light emitting amount of the illumination light source 3 can be adjusted according to the external light amount detected by the external light amount detecting light receiving element 5. I have.

The light receiving element 2 for reading and the light source 3 for illuminating are held by a sensor base 7 in a state of being opposed to the board 1, and this sensor base 7 is supported by a chassis 8 and the surface except for the surface facing the board 1 is removed. The three sides are covered by a cover 9 having a substantially U-shaped cross section. The travel reading unit 4 is shown in FIG.
Has a length corresponding to substantially the entire length of the board 1 in the vertical direction, and a plurality of reading light-receiving elements 2 and illuminating light sources 3 are arranged in the longitudinal direction at equal intervals, as shown in FIG. The board 1 is moved by moving the traveling reading unit 4 in the left-right direction.
The entire image can be read.

In the traveling reading unit 4, light is emitted from the illumination light source 3 to the surface 1 a of the board 1,
The reflected light at a is detected by the reading light receiving element 2 via the lens 10. On both sides of the light receiving element 2 for reading and the light source 3 for illuminating, a light shield 1 made of a flexible cloth member is provided.
1 is fixed to the chassis 8, and external light enters the light receiving element 2 for reading through a slight gap between the light shielding body 11 and the board 1.

Illumination light source 3 and light receiving element 5 for detecting external light quantity
Is electrically connected to a lighting control unit 13 as a control unit for adjusting the light emission amount of the illumination light source 3.
In step 3, the external light quantity signal from the external light quantity detecting light receiving element 5 is processed, and the operation of the illumination light source 3 is controlled. The reading light receiving element 2 is electrically connected to a reading control unit 14, which controls the operation of the reading light receiving element 2 and processes an image signal from the reading light receiving element 2.

The external light amount detecting light receiving element 5 is provided so as to detect the external light amount on the outer surface of the traveling reading unit 4. Here, the external light on the surface of the cover 9 opposite to the board 1 is used for detecting the external light amount. The light is detected by the light receiving element 5, and more specifically, external light is incident on the light receiving element 5 for detecting an external light amount disposed inside the cover 9 through a hole 15 formed in the cover 9.

FIG. 2 shows an example in which the position of the light receiving element 5 for detecting the amount of external light is changed. Here, a plurality (here, a pair) of external light amount detecting light-receiving elements 5 are provided so that the external light amount can be detected on both opposite sides of the reading light-receiving element 2 of the traveling reading unit 4. In this case, for example, the illuminating light source 3 is determined based on a large value of the external light amount detected by each of the pair of external light amount detecting light receiving elements 5.
Adjust the light emission amount of Thus, it is possible to cope with a case where the amount of external light incident from the gap between the traveling reading unit 4 and the board 1 differs in the incident direction, and this is effective when, for example, sunlight shines through a window on the side.

The external light amount detecting light receiving element 5 may be provided at an appropriate position in the longitudinal direction (vertical direction) of the traveling reading unit 4, and in the example shown in FIG. Light receiving element 5 is provided. In addition, a configuration in which a plurality of light receiving elements 5 for detecting an external light amount are provided in a line in the longitudinal direction of the traveling reading unit 4 is also possible. In this case, various combinations of positions of the external light amount detecting light receiving element 5 on a cross section orthogonal to the longitudinal direction of the traveling reading unit 4 shown in FIGS. 1 and 2 are also possible.

When the electronic blackboard is of a type that reads an image on the board 1 in color, it is preferable to adjust the amount of light emitted from the illuminating light source 3 in accordance with the color tone of external light. That is, the light source 3 for illumination can adjust the light emission amount for each of a plurality of colors, and the light receiving element 5 for detecting the external light amount can detect the external light amount for each of a plurality of colors. In particular, the light emission amount of the illumination light source 3 is adjusted for each color in accordance with the external light amount for each color detected by the external light amount detection light receiving element 5.

In this case, as shown in FIG. 4, a color light source unit 17 composed of light sources of a plurality of colors is preferably used. Here, three sets of light sources 3a, 3b and 3c of three colors of red, green and blue are arranged at equal intervals as a set of light sources for illumination, and switching of the three color light sources 3a, 3b and 3c is performed. And the color separation by synchronizing the reading timing, the image on the board surface can be read in color even if the reading light receiving element 2 itself cannot identify the color. In the light emission amount adjustment based on the external light amount, the light emission amounts of the light sources 3a, 3b, and 3c may be individually adjusted.

FIG. 5 shows the front of a travel reading unit as a second embodiment of an electronic blackboard according to the present invention. Here, a part of the light receiving element group 21 provided in a plurality of rows in the light receiving element unit 22 is defined as an external light amount detecting light receiving element 21a, and light incident on the outer surface of the traveling reading unit 23 is input to the external light amount detecting light receiving element 21a. A light guide (light guide means) 24 for selectively guiding is provided. The external light amount detecting light receiving element 21 a is located at an end of the light receiving element unit 22, is outside the reading range of the board 1, does not substantially participate in reading, and is a reading part which is the remaining part of the light receiving element group 21. The image is read by the light receiving element for use 21b.

As shown in FIG. 6, the light guide 24 has external light receiving surfaces 25 provided on both sides thereof exposed to the outer surface of the traveling reading unit 23, and an external light extracting surface 26 at the center thereof has an outer surface. The light incident on the external light intake surface 25 is guided to the external light extraction surface 26, and the light radiated from the external light extraction surface 26 is directly opposed to the light intensity detection light receiving element 21a. 2
1a. A pattern that reflects light is formed on the surface of the light guide 24 except for the external light receiving surface 25 and the external light extracting surface 26. In this configuration, the external light amount detecting light receiving element 21a can detect the external light amount on both sides opposite to each other across the reading light receiving element 21b in the traveling reading unit 23. Further, since the external light amount at a portion close to the board 1 is detected, more appropriate control can be performed based on the external light amount approximate to the external light amount actually incident on the reading light receiving element 21b.

[0024]

As described above, according to the present invention, since the amount of light emitted from the illuminating light source is adjusted according to the amount of external light, an appropriate read image can be obtained without being affected by the change in the amount of external light. Moreover, since the amount of light emitted from the illumination light source can be minimized, the power consumption of the illumination light source can be reduced, and the average value of the operating current can be reduced, so that the life of the illumination light source can be extended.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a traveling reading unit as an electronic blackboard according to a first embodiment of the present invention;

FIG. 2 is a sectional view showing a modification of the travel reading unit of the electronic blackboard shown in FIG.

FIG. 3 is a perspective view of the electronic blackboard shown in FIG. 1;

FIG. 4 is a front view showing a color light source unit.

FIG. 5 is a front view showing a travel reading unit as an electronic blackboard according to a second embodiment of the present invention;

FIG. 6 is a sectional view of a traveling reading unit of the electronic blackboard shown in FIG. 5;

FIG. 7 is a perspective view of an electronic blackboard to which the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Board, 1a Surface (board surface) 2 Light receiving element for reading 3 Light source for illumination 4 Traveling reading unit 5 Light receiving element for detecting external light amount 11 Light shield 13 Lighting control unit 14 Reading control unit 17 Color light source unit 21 Light receiving element group, 21a Light receiving element for external light quantity detection, 2
1b Reading light receiving element 22 Light receiving element unit 23 Traveling reading unit 24 Light guide 25 External light taking-in surface 26 External light taking-out surface

Claims (4)

[Claims] 1. An electronic blackboard having a traveling reading unit which travels in a direction along the board surface while holding a reading light receiving means for reading an image on the board surface and an illuminating light source for irradiating the board surface with light. There is provided an external light amount detecting light receiving unit for detecting an external light amount around the electronic blackboard, and the light emitting amount of the illumination light source can be adjusted according to the external light amount detected by the external light amount detecting light receiving unit. An electronic blackboard characterized by the following. 2. The external light amount detecting light receiving means is provided so as to be capable of detecting an external light amount on both sides of the traveling reading unit opposite to each other across the reading light receiving means. Electronic blackboard described in. 3. The light receiving element for reading is a light receiving element arranged in a plurality of rows in a light receiving element unit, and a part of a light receiving element group of the light receiving element unit is used as the light receiving element for detecting an external light amount. 3. The electronic blackboard according to claim 1, further comprising a light guide unit for guiding light incident on an outer surface of the traveling reading unit. 4. The illumination light source is capable of adjusting a light emission amount for each of a plurality of colors, and the external light amount detection light receiving means is capable of detecting an external light amount for each of a plurality of colors. 4. The light-emitting device according to claim 1, wherein the light-emitting amount of the illumination light source can be adjusted for each color in accordance with the external light amount of each color detected by the light-quantity detecting light-receiving unit. Electronic blackboard.