JPS58220179A - Multicolor fluorescent display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multicolor fluorescent display device, and is intended to significantly reduce the number of driving circuits and to realize an easy-to-see light emitting state.

Today, in the field of household electrical appliances, many products incorporating microcomputers are being manufactured, and products are becoming more multifunctional. Along with this multifunctionality,
In order to improve the ease of use even a little, efforts have been made to display functions using colors using multicolor fluorescent display tubes, thereby reducing the complexity that users feel.

The usage of conventional high-frequency cooking utensils will be explained below using an example. FIG. 1 is an external perspective view of the microwave oven. An oven range is a cooking device that has both a heating function using high-frequency power and a so-called oven cooking function using radiant heat or convection (conduction) heat.

In the figure, when a desired menu key is input from a menu selection keyboard 1, the type of cooking is displayed on a multicolor fluorescent display tube 2. The multicolor fluorescent display tube 2 is enlarged and explained in FIG.
"Nirerif strong" segment a2 is 1. Indicates manual cooking mode with high-power dielectric heating, "Niretsku weak" segment a
3 indicates a low-output manual cooking mode, an "oven" segment a4 indicates manual oven cooking using an electric heater, and a "grill" segment a5 indicates manual browning and weight cooking using an electric heater. On the other hand, as a display for cooking information during automatic cooking using sensor control,
The "wrap" segment b1 shows cooking information asking for the food to be wrapped, the "reservation" segment b2 shows that the cooking is currently on standby for reservation cooking, and the "preheat" segment b3 shows the cooking information for wrapping the food. The "defrosting" segment b4, which indicates that preheating is in progress, indicates that frozen food is being thawed and cooked. Furthermore, during oven cooking using the electric heater, there are segments d1 to d1□ for displaying the current temperature and set temperature inside the oven.

The seven segments from cl to 07 are numeric display segments. Yes, e is a colon segment indicating that the time is being set.

The display bodies described above use a plurality of emitting colors in order to improve ease of use. When using an electric heater, a red light emitter is used to appeal to the user's visual sense. In FIG. 2A, "Oven Ja4, [
Grille Ja5, "preheat" b3, and temperature display segments from dl to d1□ are red light emitters. Other segments feature blue-green luminescent materials. In the figure, 01 to G5 indicated by dotted lines are mutually separated mesh electrodes, that is, grid nodes. In this way, by dividing the grid into five grids from 01 to G5, a dynamic drive system can be adopted that can reduce the number of lead wires to the anode segments, which are light emitters.

There is a static drive method that corresponds to the dynamic drive method, but in this case, although it has the advantage that the luminance can be increased compared to the dynamic drive method, the number of terminals that need to be connected to the fluorescent display tube is limited. , the number of anode segments is required, which is extremely uneconomical, and therefore, in most cases, the above-mentioned dynamic drive method is used as a drive method for fluorescent display tubes.

FIG. 2B shows the display contents when the user selects menu number 21, automatic oven cooking. "Oven" segment a4 indicating oven cooking
lights up, and the menu number ``21'' is displayed on the number display section. It's a moat, the temperature display section shows d2~d9''i! to indicate that the temperature is set at 170''C! A segment will be added. Furthermore, the "preheat" segment b3 lights up to indicate that the oven is in preheat mode. At this time, while the numeric segments c1 to C7 emit blue-green light, the other light emitting segments use red segments to visually convey that oven cooking is being performed.

By the way, the biggest difficulty in using multicolor fluorescent display tubes is how to maintain the brightness balance between the commonly used blue-green light emitting material and the other color light emitting materials. It is.

In general, the brightness ratio that can be visually perceived as well-balanced is
As shown in the table below, between blue green and shi・nodo,
The ratio is approximately 10 to 10.

<Table> On the other hand, the third table shows the brightness when changing the anode voltage.
As shown in the figure, the brightness obtained when the anode voltage is set to, for example, 30V is about 150 lux (L
UX), approximately 8 lux at the red port. However, the grid voltage is 30V.

If you try to light two colors, blue-green and red, on the same display tube using this 30V single power supply, the blue-green will appear much brighter. Therefore,
In order to get closer to the brightness ratio that looks well-balanced visually, the red anode voltage was changed from 30V to 40V or 46V.
By setting the brightness to V, the brightness is increased to 15 to 20 lux.

FIG. 4 schematically shows an example of a drive circuit for a conventional multicolor fluorescent display tube. 3 is a multicolor fluorescent display tube, and 6 is a drive circuit for its grid scan outputs G1 to G5. Further, 6 is a drive circuit for the blue green segment (anode), and 7 is a drive circuit for the red segment (anode). These drive circuits are generally composed of Darlington-connected transistor arrays. Reference numeral 4 represents a control circuit section that controls these drive circuits. Here, in order to maintain a brightness balance between blue-green and red, the power supply voltages of the drive circuit 6 and the drive circuit 7 are set to different voltages as described above.

As described above, conventional multicolor fluorescent display tubes require at least two or more types of driving power sources instead of a single one.

This not only made the drive circuit more complicated, but also increased the cost of materials for constructing a separate power supply.

The present invention realizes driving of a multicolor fluorescent display tube with a single power source, simplifies the driving circuit, and reduces costs.

An embodiment of the present invention will be described below based on the drawings.

In FIG. 6, the luminance of the blue-green phosphor and
This shows the correlation between duty factors.

Generally, the duty factor is defined as the proportion of ON time occupied in one cycle, but in the case of fluorescent display tubes, the duty factor is defined as the percentage of ON time occupied in one cycle. ) is the percentage of time that the anode voltage is applied. As can be seen from FIG. 5, in the case of blue-green, the luminance obtained when the duty factor is -1/10 is about 160 lux.

On the other hand, FIG. 6 shows the correlation between the luminance of the red phosphor and the duty factor.

From FIG. 6, the luminance when the duty factor is 1/10 is approximately Flux. Therefore, when the above-mentioned blue-green and red are lit with the same fluorescent display tube 'i', if the duty factor is not changed between blue-green and red as in the past, the above-mentioned As explained in the conventional example, balanced luminance could not be obtained unless the anode drive power supplies were separate; however, looking at Figure 6, if the duty factor for red is set to about 115, It can be seen that the brightness is improved to about 16 to 1 flux. In other words, the duty factor of the red light emitter with low luminance is set to 1, and the duty factor of the blue green light emitter with high luminance is set to 1.
/10, the mutual brightness ratio of the two colors becomes 1:0, which is the brightness balance that looks well balanced visually as shown in the table above.
It can be seen that the value is 10.

FIG. 7 shows an embodiment of the present invention in which the duty factor is changed depending on the color described above, and in the multicolor fluorescent display tube of FIG. 2A, the display of FIG. It is a timing chart of the voltage waveform applied to each terminal when lighting is on. Here, in FIG. 2B, as already explained, the "oven" segment) a4. The "preheat" segment b3 and the temperature display segments d2 to d9 are red light emitters to be lit, and the number, for example "21", is a blue green light emitter.

To briefly explain the timing diagram in Fig. 7, from G1 to G
The scan output to the grid at 61 is sequentially output every 2m5ec, and the following anode segments a1 to d1
The voltage application to □ is performed correspondingly when the grid to be lit is scanned and output.

The voltage application to a4 is as follows:
This is performed when a voltage is applied to grid G1.

At this time, the voltage application timing and application time to the "oven" segment a4 are approximately the same as the voltage application timing and application time to the grid G, 2 mBeC. These timings and times are the same for the "preheating" segment b3 and the temperature display segments d2 to d9, which are the same red light emitters. On the other hand, the voltage applied to the number segments 01 to C7, which emit blue-green light, is 1/10, which is half of the duty factor 1//+5 of the red light emitter, in order to balance the brightness with red. The application time is approximately 1m89G in this case.

Of course, if the material of the light emitting body is different, it goes without saying that these duty factors must be appropriately selected depending on the light emitters so that the brightness balance is the best.

As described above, if the duty factors for each light emitting element are set separately so that the luminance ratio is visually balanced when driving, it is possible to prepare the drive power source separately for each light emitting element as in the past. Not only does this eliminate waste, which reduces material costs, but it also saves space on the printed circuit board on which the drive power supply, etc. are formed, and as a result, it is much more compact and less expensive than conventional products. This makes it possible to drive a multicolor fluorescent display tube in a visually balanced light emitting state using a drive circuit.

[Brief explanation of drawings]

Figure 1 is an external perspective view of a conventional general high-frequency heating device;
Figures A and B are enlarged front views of main parts showing the multicolor fluorescent display device of the device, Figure 3 is a characteristic diagram showing the relationship between the anode voltage and brightness of the device, and Figure 4 is the drive circuit of the device. A block diagram showing
7 and 6 are characteristic diagrams showing the relationship between duty factor and luminance for explaining the multicolor fluorescent display device of the present invention, and FIG. 3 is a timing diagram of voltage waveforms applied to each terminal of a color fluorescent display device. 2...Multicolor fluorescent display tube, a 1 + a 2
+ a 3. a4*a6...segment, bl, b2. b3. b4...Segment, C1-C7...Segment, d1-d17.
...Segment, e...Colon segment, 01-G5...Segment. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Fig. 2 Fig. 1g 3 Positive viewing pressure (V) Fig. 4 Fig. 5

Claims (2)

[Claims] (1) A structure in which a multicolor fluorescent display tube having a plurality of emitting colors and light emitters is turned on by a dynamic driving method, and a structure in which the duty factors among the different color light emitters among the plurality of light emitters are different. A multicolor fluorescent display device. (2) The ratio of duty factors between different color luminescent materials is
2. A multicolor fluorescent display device according to claim 1, wherein the luminance ratio of each color is set to approximately the same level as a visually balanced brightness ratio.