JPH04301396A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To obtain a lighting device for a discharge lamp having a simple structure and different electric characteristic by using a memory storing the electric characteristic of the discharge lamp. CONSTITUTION:A table memory 4 stores the electric characteristic of a discharge lamp in advance. When the lamp is lighted, the data in the table memory 4 are read referring to the electric characteristic of the discharge lamp and the input voltage of a lighting device, both of which are detected by a lamp characteristic detecting part 5 and an input voltage detecting part 6, and based on the data, a lighting control part 3 controls the lamp power supplied to the discharge lamp via a lighting circuit 1. The data of the memory 4 can be written by a memory read-write part 7 from outside or the electric characteristic data of the lighting discharge lamp can be written. The lighting of the discharge lamp having the different electric characteristic can be controlled by just replacing the electric characteristic data of the discharge lamp in the table memory.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting control device for discharge lamps such as fluorescent lamps and metal halide lamps having different electrical characteristics.

0002

2. Description of the Related Art FIG. 3 shows a conventional discharge lamp lighting device. In FIG. 3, 2 is a discharge lamp, 10 is an AC power supply, 8 is a current limiting element, 9 is a starting circuit, and 11 is a lamp characteristic detection circuit.

The operation of a conventional discharge lamp lighting device is shown in FIG. 3 below.
Explain using. When voltage is supplied from the AC power source 10, the starting circuit 9 operates first, generates a high starting voltage and applies it to the discharge lamp 2, thereby starting the discharge lamp 2. When the discharge lamp 2 starts, a current controlled by the current limiting element 8 is supplied to the discharge lamp 2, and the electric characteristics (lamp voltage, lamp current, lamp power) specified for each discharge lamp are maintained.
is lit. When lamp characteristics such as lamp voltage change during lighting, the lamp characteristics detection circuit 11 detects this change and changes the output voltage of the AC power supply 10 so that the desired lamp characteristics are achieved, so that the discharge lamp 2 is constantly Controls lighting so that it has suitable electrical characteristics. That is, the lamp characteristic detection circuit 11 detects the characteristic change of the discharge lamp, and the AC power supply 10
The electric characteristics applied to the discharge lamp 2 are controlled by feeding back the output voltage and changing the output voltage. As lamp characteristics, lamp voltage and lamp power are generally detected. Since the current limiting element 8 generally operates as a constant current source, when the lamp voltage of the discharge lamp 2 increases, the electric power input to the discharge lamp 2 increases, causing overload lighting and increasing the output luminous flux. Furthermore, if this state continues for a long period of time, the lamp may be damaged or its lifespan may be shortened, so the output voltage of the AC power supply 10 is lowered and the discharge lamp 2
suppresses the input current to the

0004

[Problem to be solved by the invention] In the conventional lighting device,
In order to light lamps with different lamp characteristics, it is necessary to use a lighting device that is compatible with the discharge lamp to be lit. That is, when the lamp power is different, the power supply voltage is changed or the current limiting element is changed to control the lamp current supplied to the discharge lamp to match the lamp power to the lamp to be lit. Therefore, a large number of lighting circuits were required for each lamp. In addition, with conventional methods, a complex lighting circuit is required to control the lighting state of a discharge lamp based on multiple changing factors such as lamp voltage, lamp current, and input voltage. A method was adopted in which control was limited to 100%, and the characteristics of the discharge lamp could not be fully demonstrated.

The present invention solves the above problem, and aims to provide a lighting device for discharge lamps having different electrical characteristics with a simple configuration using a memory that stores the electrical characteristics of the discharge lamps. It is something.

[0006]

[Means for Solving the Problems] In order to solve the above problems, a discharge lamp lighting device of the present invention includes a discharge lamp, a lighting circuit connected to the discharge lamp, and a lighting circuit connected to the lighting circuit for lighting the discharge lamp. It is equipped with a lighting control section that controls the state, and a table memory that stores the electrical characteristics of the discharge lamp and supplies read data to the lighting control section,
Furthermore, it is equipped with a lamp characteristic detection section that detects lamp characteristics from the discharge lamp or lighting circuit, and an input voltage detection section that detects changes in input voltage. The electrical characteristics of the discharge lamp at the time of lighting are read out from the memory, and the lighting of the discharge lamp is controlled.Furthermore, the electrical characteristics of the discharge lamp can be written externally into the table memory, The device is equipped with a memory read/write section that has a function of writing the electrical characteristics of the discharge lamp and a function of reading the electrical characteristics of the lit discharge lamp from the table memory.

[0007]

[Operation] With the above configuration, the lamp characteristics detection section measures the characteristics during lighting, and the input voltage detection section measures changes in the input voltage, and these results are used to determine the electrical characteristics of the discharge lamp written in the table memory. Read the data. The read data is supplied to the lighting control section to change the operating characteristics of the lighting circuit, and based on this, lighting control of the discharge lamp is performed. On the other hand, the memory read/write section writes electrical characteristic data of the discharge lamp supplied from the outside into the data memory, and reads out stored data. Further, the electrical characteristics of the discharge lamp during lighting obtained from the lamp characteristics detection section are written into the table memory.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the basic configuration of a discharge lamp lighting device according to an embodiment of the present invention. In FIG. 1, 1 is a lighting circuit that starts a discharge lamp 2 and keeps it lit. 3 is a lighting control section connected to the lighting circuit 3, which controls the operation of the lighting circuit 1; Reference numeral 4 denotes a table memory connected to the lighting control section 3, which stores electrical characteristics of the discharge lamp. Reference numeral 5 denotes a lamp characteristic detection unit which detects the lamp characteristic from the output of the lighting circuit 1 and stores the lamp characteristic in the table memory 4 using the lamp characteristic as input.
Read out the electrical characteristics stored in the Reference numeral 6 denotes an input voltage detection section that detects changes in the input voltage of the lighting circuit 1, and reads out the electrical characteristics of the table memory 4 using this input voltage value as input. These read electrical characteristics are supplied to the lighting control section 3 and change the operating characteristics of the lighting circuit 1. 7 is a memory read/write section connected to the table memory 4, which has the function of writing the electrical characteristics of the discharge lamp 2 into the table memory 4 from the outside, the function of writing the electrical characteristics of the discharge lamp 2 while it is lit, and the function of writing the electrical characteristics of the discharge lamp 2 from the table memory 4. It has a function of reading out the electrical characteristics of the discharge lamp 2 while it is lit.

FIG. 2 is a block diagram showing a detailed configuration example of the discharge lighting device shown in FIG. 1. A series inverter and an LC resonant circuit are used as the lighting circuit, and the voltage and current supplied to the discharge lamp are changed by changing the operating frequency. This example shows how to control the . Furthermore, an example is shown in which the lamp characteristic detection section detects the voltage between the terminals of the discharge lamp, that is, the lamp voltage Vla.

In FIG. 2, the lighting control section 3 is composed of a drive circuit 3a and an oscillation circuit 3b, the lamp characteristic detection section 5 is composed of an A/D converter 5a, and the input voltage detection section 6 is composed of an A/D converter 6a. It consists of moreover,
The table memory 4 is composed of a memory 4a, a data control section 4b, an address synthesis section 4c, and an address switching section 4d, and the memory write/read section 7 is composed of a data conversion section 7a, a data switching section 7d, and a memory control signal generation section 7c. It is configured.

The operation of this embodiment configured as described above will be explained using FIGS. 1 and 2. The electrical characteristics of the discharge lamp 2 at the time of starting and stable lighting are stored in the memory 4a. First, the operation when a read-only memory (ROM) is used as the memory without reading or writing data from the outside will be described. When the DC power supply VDC is applied, the series inverter in the lighting circuit 1 operates. At this time, since the discharge lamp is not lit yet, an alternating current voltage is generated across the discharge lamp 2 by complementary switching of the direct current voltage VDC by the transistors Q1 and Q2. This voltage is generally set higher than the voltage when the discharge lamp is lit, that is, the lamp voltage Vla, in order to prevent the discharge lamp 2 from going out when lit. The lamp voltage Vla of the discharge lamp 2 is sent to the A/D converter 5a in the lamp voltage detection section 5 and digitized. The output of the A/D converter 5a is sent to the address synthesis section 4c of the table memory 4.
, addresses the memory 4a through the address switching unit 4d. On the other hand, the input voltage value is digitized by the A/D converter 6a in the input voltage detection section 6, and is addressed to the memory 4a through the address synthesis component 4c and the address switching section 4d in the same way as the lamp voltage signal. That is, the memory 4a is addressed with composite information of both lamp voltage values and input voltage values.

Based on the addressed data, the memory 4a supplies pre-written electrical characteristic data of the discharge lamp 2 to the lighting control section 3 through the data control section 4b. The data control section 4b is set to receive a memory input/output data switching signal from the memory control signal generation section 7c of the memory read/write section 7, and to send data in the memory 4a to the lighting control section 3. The electrical characteristic data supplied to the lighting control circuit 3 is converted into data necessary for operating the lighting circuit 1, ie, an operating frequency signal, by the oscillation circuit 3b. In the embodiment, a series inverter and a resonant circuit are used to generate a high resonant voltage and apply it to the discharge lamp 2. In the initial state, the oscillation circuit 3
A complementary signal having an operating frequency matched to the resonant frequency of the resonant circuit constituted by the inductance L and the capacitor C2 is generated from the oscillator circuit 3b and supplied to the drive circuit 3a from the oscillation circuit 3b. The drive circuit 3b applies a drive signal to the transistors Q1 and Q2 of the series inverter to cause them to perform switching operations. The discharge lamp 2 is started by such an operation.

When the discharge lamp 2 is started, the lamp voltage Vla decreases. This change in the lamp voltage Vla is digitized by the lamp characteristic detection section 5, which addresses the memory 4a, reads out new electrical characteristic data of the discharge lamp 2, and changes the operating frequency of the series inverter in the lighting circuit 1 through the lighting control section 3. change. When the operating frequency changes, the equivalent impedance of the capacitor C1 and inductance L connected in series with the discharge lamp 2 changes. As a result, the current supplied to the discharge lamp 2 is changed, the power supplied to the discharge lamp 2 is adjusted to an appropriate value, and lighting is maintained.

On the other hand, when the input voltage value changes, the voltage supplied to the discharge lamp 2 changes. Therefore, the input voltage value is measured and digitized by the input voltage detection section 6, and is synthesized with the digitized lamp characteristic signal by the address synthesis section 4c, and the memory 4a is addressed through the address switching section. In this way, the electrical characteristic data in the memory is read in response to changes in the input voltage, the operating frequency of the lighting circuit 1 is changed through the lighting control section 3, and the power supplied to the discharge lamp 2 is controlled.

In this way, even if the electrical characteristics of the discharge lamp or the input voltage value to the lighting circuit changes, the lighting circuit will respond accordingly based on the electrical characteristics of the target discharge lamp set in advance in the memory. can be operated to control the lighting state of the discharge lamp and maintain stable lighting. Furthermore, if the memory is replaceable, discharge lamps having different electrical characteristics can be lit with the same lighting device by simply replacing the memory.

Next, the memory 4a is a rewritable memory (
The operation in case of RAM) will be explained. When the memory 4a is used as a RAM, in addition to the above-mentioned operation as a ROM, there are operations for writing the electrical characteristics of the discharge lamp into the memory from the outside, and operations for writing the electrical characteristics of the discharge lamp during lighting into the memory. In this case, when used in the read mode, the operation is the same as when the memory 4a is a ROM, so a description of the operation will be omitted.

First, the operation of writing data from the outside will be explained with reference to FIG. From external control signal input,
A signal indicating the write mode of electrical characteristic data of the discharge lamp in the memory 4a is input to the memory control signal generating section 7c in the memory read/write section 7. The memory control signal generator 7c generates a memory input/output data switching signal for switching data input to the memory 4a. It also generates a memory R/W switching signal for operating the memory 4a in write mode. An external address input corresponding to the electrical characteristics of the discharge lamp or the input voltage value is input to the address switching section 4d, and the memory 4a is addressed by a memory address switching signal from the memory control signal generating section 7c. On the other hand, external data is supplied to the data switching section 7b in the memory read/write section 7. The data switching unit 7b selects external data and supplies it to the table memory 4 based on the memory input/output data switching signal from the memory control signal generating unit 7c. In the table memory 4, external data is supplied to the memory 4a through a data control section 4b which is switched by a memory input/output data switching signal. In this way, the external address and external data are input to the memory 4a. On the other hand, a data write command to the memory 4a is input from the external control signal input, and in response to this, a memory R/W switching signal is input from the memory control signal generator 7c to the memory 4a, so that the external data is stored in the memory 4a. is memorized. Thereby, a lighting circuit compatible with discharge lamps having different electrical characteristics can be realized without replacing the memory 4a. In addition, before lighting, external data is supplied and stored,
If this data is then used for lighting, different discharge lamps can be lit using one lighting circuit, which is effective. Furthermore, if the memory read/write unit 7 is set using an external control signal input so that the data in the memory 4a is output to the outside, the data in the memory 4a can be checked externally, and the discharge lamp Electrical characteristics can be easily understood.

Next, the operation of storing the electrical characteristics of the discharge lamp in the table memory 4 during lighting will be explained. The lamp voltage signal digitized by the lamp characteristic detection section 5 is sent to the memory read/write section 7. In the memory read/write section 7, the data conversion section 7a converts the data into a data format that matches the storage format of the memory 4a. The output of the data conversion section 7a passes from the data switching section 7b to the data control section 4b and is input as data to the memory 4a. On the other hand, the lamp voltage of the discharge lamp 2 is input as an address to the memory 4a, and thereby lamp voltage data is recorded in the memory 4a. As a result, it is possible to change the lamp power of the discharge lamp in response to changes in characteristics of the discharge lamp over time or changes in characteristics due to ambient conditions, control the lighting state, and maintain stable lighting.

In this way, by storing the electrical characteristics of the discharge lamp using the table memory, the circuit configuration can be simplified by simply exchanging the data in the memory without changing other parts of the lighting device. Can light discharge lamps with different electrical characteristics. In addition, since a large amount of data can be stored in the memory, detailed lighting control can be performed with a simple circuit configuration, even for multiple parameters such as the multiple electrical characteristics of the discharge lamp and the input voltage value of the lighting device. It is. Furthermore, since the control source is configured to read data from the memory, the response is fast and control can follow even sudden changes in lamp characteristics.

In the embodiment, a lighting circuit using a series inverter is shown, but similar effects can be obtained with other systems such as a bridge type lighting circuit. Further, although the embodiment shows a method of changing the lighting frequency, it is also effective for other lamp characteristic control methods (for example, PWM method). Furthermore, although we have shown a method in which the electrical characteristic detection section detects the lamp voltage of the discharge lamp, it may also be possible to measure the lamp current or lamp power, or measure the light output from the discharge lamp with a photodetector and convert it into an electrical signal. Similar effects can be obtained by using

[0021]

As described above, according to the present invention, a discharge lamp, a lighting circuit connected to the discharge lamp, a lighting control unit connected to the lighting circuit and controlling the lighting state of the discharge lamp,
A table memory connected to the lighting control section, a lamp characteristic detection section connected to the lighting control section to detect lamp characteristics from the lamp or lighting circuit, and an input voltage detection section connected to the table memory to detect changes in input voltage. Furthermore, by being equipped with a data read/write section that connects to the table memory and controls reading and writing of data in the table memory, it is possible to simply exchange data in the memory without changing other parts of the lighting device. , it is possible to light discharge lamps with different electrical characteristics with a simple configuration, and the effect is great.

Furthermore, since a large amount of data can be stored in the memory, control over multiple parameters such as multiple electrical characteristics of the discharge lamp and input voltage values of the lighting device can be realized with a simple circuit configuration, and the effect is big.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic configuration of a discharge lamp lighting device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a detailed configuration example of the discharge lamp lighting device of the present invention.

FIG. 3 is a block diagram showing a conventional discharge lamp lighting device.

[Explanation of symbols]

1. Lighting circuit 2 Discharge lamp 3. Lighting control section 4 Table memory 5 Lamp characteristics detection section 6 Input voltage detection section 7 Memory read/write section

Claims (6)

[Claims] 1. A discharge lamp, a lighting circuit for starting the discharge lamp and maintaining lighting, a lighting control section connected to the lighting circuit and controlling the operation of the lighting circuit, and a lighting control section connected to the lighting control section for controlling the electricity of the discharge lamp. A discharge lamp lighting device comprising a table memory storing characteristics, and configured to control the electrical characteristics of the discharge lamp using information in the table memory. 2. The discharge lamp lighting device according to claim 1, further comprising a lamp characteristic detecting section connected to the table memory to detect lamp characteristics of the discharge lamp and read out the table memory using the lamp characteristics as input. 3. The discharge lamp lighting device according to claim 1, further comprising an input voltage detection section connected to the table memory to detect the input voltage value of the lighting circuit and read out the table memory using the input voltage value as input. 4. The discharge lamp lighting device according to claim 1, wherein the table memory comprises a read-only memory. 5. The discharge lamp lighting device according to claim 1, wherein the table memory is comprised of a readable and writable memory. 6. Connected to a table memory, writing the electrical characteristics of the discharge lamp from the outside into the table memory, writing the electrical characteristics of the discharge lamp while being lit, and writing the electrical characteristics of the discharge lamp while being lit from the table memory. 2. The discharge lamp lighting device according to claim 1, further comprising a memory read/write unit capable of reading out the information.