JPS63280573A - Electronic blackboard - Google Patents

Abstract

PURPOSE:To prevent a red line from converting to a black line and said line from subjected to thermal recording by recording a red thin-line image on a sheet with emphasis. CONSTITUTION:A screen 12 written and recorded by handwriting is turned and a thermal head 7 is driven based on image information reading the write recording on the screen 12 to attain 2-color recording. A control means is provided, which records the red thin-line written on the screen 12 with emphasis processing. Much energy is applied to the thermal head 7 with respect to initial several lines (e.g., 16 lines) in advance. Thus, it is prevented that the red print is converted into a black print at several tens line at the start of the print.

Description

[Detailed Description of the Invention] [Technical Field] The present invention rotates and moves a screen on which writing is recorded by hand, etc., and drives a thermal head based on image information read from the writing on this screen. The present invention relates to an electronic blackboard that performs color recording, and more particularly to an electronic blackboard that can record handwritten images on a screen in two colors.

[Prior art]

FIG. 8 is a configuration diagram showing a conventional electronic blackboard.

The electronic blackboard 10 has an optical unit 13 for reading image information on a screen 12 (to be described later), a drive unit l4 for moving the screen 12, and a screen l2 on which image information is written with marker ink, etc., in a frame 11 constituting the exterior. The optical unit 13 is composed of a rotationally moving screen unit 15, a light source 16 that irradiates light onto the screen 12, and an optical information signal that is generated when the light from the light source 16 is reflected on the screen 12. a mirror 17 that allows the reflected light from the mirror 17 to pass through a slit 18
．． A CCD (solid-state imaging device) 20 that is read through a lens 19 is provided.

The drive unit 14 includes a motor 21 that generates driving force,
A gear 23 transmits the driving force generated by the motor 21 to the screen unit 15 via a belt 22.

Further, the drive unit 14 is provided with a screen sensor 24 that detects the home position of the screen 12.

The screen unit 15 has two take-up rolls 25 and 26 connected to a drive means (not shown) at both ends in the longitudinal direction, and a screen 12 on which image information is written using marker ink or the like is stretched between nine take-up rolls 25 and 26. ing.

In the above configuration, after writing the text 5 image etc. on the screen 12 using marker ink etc., the drive unit 1
4 to rotate the screen unit 15.

When the image on the screen 12 moves downward, it is illuminated by the light source 16, and the light information of the illumination portion is transmitted to the mirror 17 of the optical unit 13. The light is received by the CCD 20 via the slit 18 and the lens 19.

The CCD 20 converts optical information into an electrical signal, and based on this electrical signal, drives a thermal head (not shown) to heat colored paper (thermal paper) to perform thermal recording.

However, since conventional electronic blackboards used thermal paper that could produce only a single color (black), the printing color was limited to one color, and the recording on the screen 12 had to be a single color.

To solve this problem, two-color thermal paper has been proposed that allows recording in two colors, red and black.

That is, as shown in FIG. 9, one side of the base layer 41 is sequentially coated with red colored N42. This is a two-color thermal paper 40 on which a decolorizing layer 43 and a black coloring layer 44 are formed, and one of the two colors is developed depending on the intensity of energy applied by the thermal head.

This color development explanatory diagram is shown in FIGS. 10 to 12.

When normal energy is applied to the thermal head, the first
As shown in Figure 0, black coloring is performed.

When energy is further applied, the energy reaches the color erasing layer 43 as shown in FIG. 11, and the black color is erased.

When more energy is applied, the energy reaches the red color jli 42 as shown in FIG. 12, and red color is produced.

In this way, two-color thermal paper requires approximately three times as much energy to produce red coloring as it does to normally produce black coloring.

However, when such red-coloring energy is applied to a thermal head, the lifespan of the thermal head is exponentially shorter than when black-coloring energy is applied.

In consideration of this point, the energy for red printing is set by setting values S and l so that it becomes the minimum within the red printing energy, as shown in FIG.

However, in the case of such two-color thermal paper, if energy for red coloring is applied, the thermal head will not last long due to the large amount of power, so it is necessary to suppress the applied energy.

The thermal head also has a substrate 45 as shown in FIG.
A heat sink 47 is installed adjacent to the heating element section 46 held in the
Therefore, even if the heating element section 46 generates heat due to the voltage supply, the heat sink 47 is cold at the beginning of the second stage, so the heat is taken away by the heat sink 47, and the heat necessary for red coloring cannot be obtained.

For this reason, there is a problem in which the red print becomes black in the first ten or so lines of printing.

〔the purpose〕

The present invention has been made in view of the above, and an object thereof is to provide an electronic whiteboard capable of printing in 42 colors without affecting the life of the head.

〔composition〕

One aspect of the present invention is to achieve the above object.

In electronic blackboards, a screen on which writing has been recorded by hand, etc. is rotated, and a thermal printer is driven based on image information read from the writing on the screen to perform two-color recording. The apparatus is provided with a control means for performing 1-emphasis processing on a thin red line and recording the result.

Embodiments of the electronic whiteboard according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a block diagram of an electronic blackboard according to the present invention, which includes an optical system 1 that transmits two color components in reflected light illuminated by a light source 16, and CCDs 2 and 3 that read each of the two color lights. An image processing unit 4 that generates image data of black and red signals based on the outputs of these CCDs, a CPU 5 that executes one-image reading and printing control, and a memory that stores programs and image data for operating the CPU 5. A thermal head 7 that colors two-color thermal paper based on image data 6 and 9, a sensor switch group 29 that controls on/off the motors 9a, 9b, and 21 under the control of the CPU 5, and a group of sensors and switches 29 that control starting, stopping, and initialization. Input/output (Ilo) for inputting output signals of the operation panel 30 for setting
) interface 8, printer drive motors 9a, 9b and screen rotation motor 21 connected to the interface 8, and a thermistor 27 for detecting the temperature of the thermal head 7.

An A/D converter 28 digitally converts the output of the thermistor 27, and a sensor/digital converter 28 that detects the operating state of each part of the drive system.
It is composed of a switch group 29 and the operation panel 30.

FIG. 2 shows a plan view of the optical system 1, which includes a red filter 31 that transmits only the red component of the reading light, a blue filter 32 that transmits only the blue component of the reading light, and a Lens 33 that images the light onto CCD 2
and a lens 34 that images the light from the blue filter 32 on the CCD 3.

Each optical path consisting of a filter and a lens for the red color and the blue color is arranged in parallel in the horizontal direction.

In the above configuration, when the start button (not shown) provided on the operation panel 30 is pressed, the motor 9a,
9b and 21 start up.

The screen 12 rotates, and in the process, the red and black data of the image on the screen 12 are read separately by the CCDs 2 and 3 as shown in FIG. Red memory (RMEM) and blue memory (BMEM) in the specified memory area within 6
are individually stored in each.

The data in the memory 6 is displayed as a red line by the CPU 5.
The black line and the black line are read out to the thermal head alternately one line at a time.

At this time, red data and black data are printed twice for one line.

For example, assume that the black line is printed first, and then the red line is printed, and the conveyance speed of the two-color thermal paper is set to less than half the speed of one-color black, and the two-color thermal paper is
Make it compatible with turning.

Figure 4 shows the relationship between the number of data and energy for each strobe. When the number of data is small, increase the energy,
A control example of the present invention is shown in which energy is reduced as the number of data increases.

Figure 5 shows the relationship between the number of lines in sub-scanning and energy.
Since the thermal response of the thermal head has a slow rise, even if a constant energy is applied to the thermal head regardless of the number of lines, the thermal response actually drops as shown by the broken line.

Therefore, in the present invention, as shown in FIG.

A large amount of energy is applied in advance to the first few lines (for example, 16 lines).

The processing of the present invention that takes into consideration the following two points will be explained with reference to the flowchart of FIG.

First, the number of data for each strobe is read (step 71), and it is determined whether the number of data is 0 (step 72).
).

If it is 0, count the number of blank lines in step 84.
), if it is not 0, it is determined whether the number of data is smaller than N (step 73).

If it is smaller than N, read the A+B-emphasized pulse width data corresponding to the number of data (step 74), and
If it is larger, data on the pulse width of B emphasis is read (step 75).

After completion of step 74 or 75, energy is supplied to the head (step 76).

Next, it is determined whether the sub-scanning line is larger than 16 lines (step 77), and if it is larger than 16 lines, the number of data for each strobe is read (step 78), and the data of the pulse width that is not emphasized by 1 is read. (Step 7
9).

Then, energy equivalent to the pulse width is supplied to the head.
(Step 80).

Furthermore, it is determined whether the continuous line has ended (step 81), and if it has not ended, the number of lines is counted (step 82).

If it is finished, it is determined whether the output of one page is finished or not (step 83), and if it is finished, all processing is finished,
If the output of one page is not yet completed, the process moves to step 84, and then it is determined whether the number of non-print lines is greater than K (heat dissipation time (number of lines) of the thermal head) (step 85).

If the number of non-print lines is greater than K, the process returns to step 71, and if it is less than K, the process returns to step 78 and the subsequent processes are repeated.

〔effect〕

As explained above, according to the electronic blackboard according to the present invention,
Since the red line image on the sheet is emphasized and recorded, it is possible to prevent the red line from being thermally recorded with black edges.

Furthermore, the life of the thermal head can be extended.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a plan view of the optical system 1 shown in FIG. 1, FIG. Figure 4 is a characteristic diagram showing the relationship between the number of data and energy for each strobe, Figure 5 is a characteristic diagram showing the relationship between the number of lines in sub-scanning and energy, and Figure 6 is a characteristic diagram showing the relationship between the number of lines in sub-scanning and energy. 7 is a characteristic diagram showing the relationship between number and energy, and FIG. 7 is a flowchart showing a processing example of the present invention. FIG. 8 is a configuration diagram showing a conventional electronic blackboard. Fig. 9 is a cross-sectional view showing an example of two-color thermal paper, Figs. 10 to 12 are explanatory diagrams of color development of two-color thermal paper, and Fig. 13 is a head for printing with conventional two-color thermal paper. is an energy application characteristic diagram of
FIG. 14 is a front view showing the configuration of the thermal head. Explanation of symbols 1...Optical system 2, 3...CCD 4...Image processing unit 5...CPU 6...Memory 7...Thermal head 8...Input/output interfaces 9a, 9b, 21...Motor 12 ... Screen 14 ... Drive unit 15 ...
Screen unit 16...Light source 31...Red filter 32...Blue filter 33, 34...Lens 40...Two-color thermal paper

Claims (2)

[Claims] (1) In an electronic blackboard that performs two-color recording by rotating a screen on which writing has been recorded by handwriting, etc., and driving a thermal head based on image information obtained by reading the writing on the screen, An electronic blackboard characterized by being provided with a control means that performs emphasizing processing and records a thin red line written. (2) The electronic blackboard according to claim 1, wherein the energy applied to the thermal head is increased for recording with a predetermined number of sub-scanning lines or less.