JP2006164698A - Discharge lamp lighting device and video display device using the same - Google Patents

Abstract

【Task】
Providing a technique capable of investigating the cause of a protection operation performed in a discharge lamp lighting device in a time zone after the end of the operation.
[Solution]
A nonvolatile memory such as an EEPROM is provided, current information and voltage information at a predetermined circuit point in the discharge lamp lighting device in a predetermined period are detected and stored in the memory, and read out after the predetermined period has elapsed. The configuration is to be analyzed.
[Selection] Figure 2

Description

  The present invention relates to a discharge lamp lighting device used for an image display device such as a liquid crystal projector, and more particularly to a technique for investigating the cause of the protection operation when the protection operation is performed.

  Conventionally, as a light source of an image display device such as a liquid crystal projector, a high-pressure discharge lamp (discharge lamp) such as a metal halide lamp or a high-pressure mercury lamp has been used as a light source with high conversion efficiency and close to a point light source. A dedicated discharge lamp lighting device is used for lighting the high-pressure discharge lamp, and a voltage and a current necessary for lighting are supplied from the discharge lamp lighting device to the high-pressure discharge lamp. As a prior art of the discharge lamp lighting device, as described in the literature, for example, there is one described in JP-A-5-74583 (Patent Document 1). In this publication, in order to maintain a constant power consumption of the HID lamp and to provide a lighting device for the HID lamp with high lighting efficiency, the HID lamp is obtained from the lamp current flowing in the HID lamp and the voltage across the HID lamp. There is described a lamp lighting control technique using a microcomputer in which power consumption is calculated and a supply current value to the HID lamp is controlled according to a difference between the calculation result and a set value.

JP-A-5-74583

In a conventional video display device such as a liquid crystal projector, for example, when an abnormality occurs for some reason, in general, a protective function is activated to perform a protective operation, and the discharge lamp is turned off. It is difficult to investigate the cause of the protection operation. This also applies to the technique described in Japanese Patent Laid-Open No. 5-74583.
In view of the state of the prior art, the problem of the present invention is that the discharge lamp lighting device or the video display device using the discharge lamp lighting device or the image display device using the discharge lamp lighting device causes the protection operation even when the discharge operation is turned off. It is to be able to investigate accurately and easily.
An object of the present invention is to solve such problems and provide a discharge lamp lighting device technology that is easy to use.

  In order to solve the above-mentioned problems, in the present invention, a nonvolatile memory such as an EEPROM is provided to detect voltage information and current information at a predetermined circuit point in a discharge lamp lighting device in a predetermined period including a protection operation period. Then, it is stored in the memory, and after the predetermined period has elapsed, it is read and analyzed.

  According to the present invention, in a discharge lamp lighting device or an image display device using the discharge lamp lighting device, it is possible to accurately and easily determine the cause of a protective operation for turning off the discharge lamp.

Embodiments of the present invention will be described below with reference to the drawings.
1-7 is explanatory drawing of the Example of this invention. FIG. 1 is a configuration diagram of a projection-type image display device as an embodiment of the present invention, FIG. 2 is a configuration example diagram of a discharge lamp lighting device as an embodiment of the present invention, and FIG. 3 is a discharge lamp lighting of FIG. FIG. 4 is a diagram illustrating an example of an observation result of an output voltage of a power control circuit in the discharge lamp lighting device of FIG. 2, FIG. 5 is a diagram illustrating an example of a mapping procedure of information stored in a memory, FIG. 6 is an explanatory diagram of various failures in the discharge lamp and the discharge lamp lighting device, and FIG. 7 is a diagram illustrating a display example of a failure state in the discharge lamp or the discharge lamp lighting device. The discharge lamp lighting device of FIG. 2 is used for the projection type image display device of FIG.

  In FIG. 1, the reflector 77 and the discharge lamp 13 constitute a light source unit that emits light from the back surface of the image display element 76. The light transmitted through the video display element 76 is projected onto the screen 74 by the optical system 75. The video display element 76 is, for example, a liquid crystal panel, and is driven by a drive circuit 79 based on a video signal, and modulates irradiated light corresponding to the video signal to form an optical image. The optical image is enlarged and projected on the screen 74 and displayed as an image. The discharge lamp lighting device 80 performs activation and lighting control of the discharge lamp 13.

FIG. 2 shows the configuration of the discharge lamp lighting device 80 as an embodiment of the present invention.
In FIG. 2, 1 is a power input terminal, 2 is a MOS-FET, 3 is a diode, 4 is a choke coil, 5 is a capacitor, 6 and 7 are resistors, 8, 9, 10 and 11 are MOS-FETs, 12 is Resistor, 13 is a discharge lamp, 14 is an igniter circuit, 15 is an arithmetic processing circuit, 18 is a PWM control circuit, 19 is an ON / OFF signal input terminal of the PWM control circuit 18, and 20 is a control voltage of the PWM control circuit 18 Input terminal 21 is a drive circuit for driving MOS-FET 2, 22 is a drive circuit for driving MOS-FETs 8, 9, 10, 11, 23 is an ON / OFF signal input terminal for drive circuit 22, 24, 25 Is an input terminal of the drive circuit 22, 26 is a terminal for inputting a signal for starting lighting of the discharge lamp 13 (hereinafter referred to as a lamp on signal), and 27 is serial data. 28 is a serial data receiving terminal (hereinafter referred to as RXD), 29 is an EEPROM as a non-volatile memory, and 30 is an output controlled by controlling the power from the input power source side. A power control circuit 31, an AC conversion circuit that converts the output power from the power control circuit 30 to AC, and a thermistor 32 that detects the temperature of the discharge lamp lighting device 80 and outputs a corresponding signal. , 33 and 34 are resistors. The igniter circuit 14 generates a high voltage pulse for starting lighting of the discharge lamp 13 based on the output of the AC conversion circuit 31. The arithmetic processing circuit 15 detects output voltage information from the voltage generated in the resistors 6 and 7 based on the output power from the power control circuit 30, and the driving current of the discharge lamp 13 from the voltage generated in the resistor 12. Information is detected, and the PWM control circuit 18 of the power control circuit 30 is controlled based on the detected output voltage information and drive current information so that the output power of the power control circuit 30 becomes constant. Further, the arithmetic processing circuit 15 detects input voltage information of the power control circuit 30 from the voltage generated in the resistors 33 and 34 based on the input power to the power control circuit 30, and from the output signal of the thermistor 32. Detects the temperature of the discharge lamp lighting device 80, particularly the temperature in the vicinity of the power control circuit 30 and the AC conversion circuit 31. The power control circuit 30 includes a MOS-FET 2, a diode 3, a choke coil 4, a capacitor 5, a drive circuit 21 and a PWM control circuit 18, and an AC conversion circuit 31 includes MOS-FETs 8, 9, 10, 11, and A drive circuit 22 is provided.

The arithmetic processing circuit 15 is constituted by, for example, a microcomputer, detects output voltage information VS of the power control circuit 30 from the voltage divided by the resistors 6 and 7 by the built-in analog / digital converter AD, and detects the resistor. 12 detects output current information IS as drive current information of the discharge lamp 13 from the voltage generated at 12, and detects input voltage information VS ₂ of the power control circuit 30 from the voltage divided by the resistors 33 and 34. To do. Further, the arithmetic processing circuit 15 monitors the temperature of the discharge lamp lighting device 80 depending on the output signal TS of the thermistor 32. The arithmetic processing circuit 15 also calculates the output power of the power control circuit 30 based on the detection results of the output voltage information VS and the output current information IS so that the output power becomes constant. A limit voltage is applied to 18 control voltage input terminals 20 to control the PWM control circuit 18. Further, the arithmetic processing circuit 15 uses the detected information as various limit values LV ₁ (limit value of the output voltage of the power control circuit 30) and LV ₂ (output current of the power control circuit 30) determined in the arithmetic processing circuit 15. LV ₃ (overheat limit value of the temperature of the discharge lamp lighting device 80), LV ₄ (input voltage limit value of the power control circuit 30). As a result of comparison, when the voltage value of the output voltage information VS of the power control circuit 30 as detection information becomes LV ₁ or more, when the value of the output signal TS of the thermistor 32 as detection information becomes LV ₃ or more, Alternatively, when the voltage value of the input voltage information VS ₂ of the power control circuit 30 as the detection information becomes LV ₄ or more, the arithmetic processing circuit 15 performs PWM so that the discharge lamp lighting device 80 stops the lighting operation. Control signals are transmitted to the ON / OFF signal input terminal 19 of the control circuit 18 and the ON / OFF signal input terminal 23 of the drive circuit 22. Further, when the output current value of the output current information IS as the detection information becomes equal to or higher than LV ₂ , the arithmetic processing circuit 15 limits the output current by the current value determined by the limit value LV _2. As described above, the PWM control circuit 18 is controlled by applying a control voltage to the control voltage input terminal 20 of the PWM control circuit 18.

  An EEPROM 29 as a nonvolatile memory is connected to the arithmetic processing circuit 15, and based on an instruction from the arithmetic processing circuit 15, the output voltage information of the power control circuit 30 or the driving current information of the discharge lamp 13 in a predetermined period. (= The output current information), or the input voltage information of the power control circuit 30, the output voltage information, the drive current information of the discharge lamp 13 (= the output current information) in a predetermined period, or At least one of the output information of the thermistor 32 is stored. Reading of the stored information is also performed based on an instruction from the arithmetic processing circuit 15.

The arithmetic processing circuit 15 reads information stored from the EEPROM 29 after the predetermined period, and analyzes and discriminates the state of the discharge lamp 13 or the discharge lamp lighting device 80 during the predetermined period based on the information. To do.
Hereinafter, the same reference numerals as those in FIG. 2 are used for the components of the apparatus in FIG. 2 used in the description of FIGS.

  FIG. 3 is an explanatory diagram of the operation of the discharge lamp lighting device 80 of FIG. 2, from when a power supply voltage is applied to the discharge lamp lighting device 80 and receiving an input from the lamp-on input terminal 26 until a stable lighting state is achieved. 6 is a timing chart showing a change in output voltage of the power control circuit 30 of FIG.

In FIG. 3, s ₁ is a lamp-on signal, which indicates a signal at the lamp-on input terminal 26. When the lamp-on signal s ₁ is input at the time t ₀ (becomes active high), the discharge lamp 13 is still in the non-lighting state at that time, so that the power control circuit 30 outputs the maximum voltage as its output voltage. V ₃ is output. Further, a high voltage pulse from the igniter circuit 14 is superimposed on the maximum voltage V ₃ to become a voltage V ₄ , and the voltage V ₄ is applied to the discharge lamp 13, so that the discharge lamp 13 is activated and lit. Next, the discharge lamp 13, a glow discharge of the high voltage and small current is started at time t _1, further transition to the arc discharge time t ₂ at low voltage and high current. In the discharge lamp 13, the lamp voltage increases as the temperature increases due to these discharges. Furthermore, the operation of the AC conversion circuit 31 at the time point t ₃ is started, the discharge lamp 13 shifts to the AC lighting mode. Thereafter, when the steady voltage V ₁ is reached at time t ₄ , the power control circuit 30 supplies constant power to the discharge lamp 13 by constant power control.

Hereinafter, storage of the operation state of the discharge lamp lighting device 80 for a predetermined period will be described. In this embodiment, the operation state is observed (analyzed and discriminated) by output voltage information VS of the power control circuit 30, drive current information of the discharge lamp 13, that is, output current information IS of the power control circuit 30, and output signal TS of the thermistor 32. It is assumed that the arithmetic processing circuit 15 performs based on one of the input voltage information VS ₂ of the power control circuit 30 or a combination thereof.

First, an observation method of the output voltage information VS will be described. The arithmetic processing circuit 15 performs AD conversion of the output voltage information VS at a sampling interval T by an internal analog / digital converter AD, and converts it into, for example, an 8-bit digital value. FIG. 4 is a diagram showing an example of an actual measurement result of the output voltage information VS, in which the 8-bit output voltage VS is plotted at the sampling interval T. When the sampling interval T is, for example, 50 × 10 ⁻³ s, FIG. 4 shows the waveform of the output voltage information VS during 50 × 10 ⁻³ s × 20 = 1 s. FIG. 4 shows an example of a waveform when a lamp rupture occurs due to a malfunction of the discharge lamp 13 at time t = 10. When the discharge lamp 13 bursts, the resistance value of the discharge lamp 13 becomes infinite, so that the output current IS does not flow. On the other hand, the arithmetic processing circuit 15 operates to keep the power constant at this time, and therefore controls the PWM control circuit 18 to increase the output voltage VS. As a result, after time t = 10, the output voltage VS exceeds the output voltage limit value LV ₁ . Although not shown in FIG. 4, when the output voltage VS exceeds the output voltage limit value LV ₁ for a certain period, the arithmetic processing circuit 15 performs a protection function by performing a protection operation, and performs PWM control. The operation of the circuit 18 and the drive circuit 22 is stopped. In FIG. 4, the protection operation is performed after time t = 21. When the output voltage information having the waveform as shown in FIG. 4 is stored in the EEPROM 29, the arithmetic processing circuit 15 reads the output voltage information VS stored from the EEPROM 29 after the protection operation period, and analyzes and discriminates it. The cause of the protection operation can be determined accurately and easily. That is, from the result of FIG. 4, it is determined that there is a high possibility that the discharge lamp 13 has ruptured.

Next, a method for storing the output voltage information VS of the power control circuit 30 will be described below.
FIG. 5 is a diagram showing a procedure for mapping data of the output voltage information VS to the EEPROM 29. The EEPROM 29 is connected to the arithmetic processing circuit 15 and has a configuration capable of reading and writing information data based on instructions from the arithmetic processing circuit 15. The reading / writing of information data to / from the EEPROM 29 uses, for example, serial communication using two data lines and a clock line. In particular, the data line can be used to read and write data by using both the EEPROM 29 and the arithmetic processing circuit 15 for input / output using an open collector (or open drain) terminal. Since this communication method is general, such as the I ² C bus format, a detailed description thereof will be omitted.

First, in FIG. 5A, the data of the output voltage information VS at time t = 0 in FIG. 4 is written to the address [0] of the EEPROM 29 based on the instruction of the arithmetic processing circuit 15. The timing for starting to store data for the time t = 0, i.e. first output voltage information VS is, for example lamp-on signal s ₁ in FIG. 3 is active High state, and the time t0 to the discharge lamp 13 starts lighting, The time t4 when the power becomes stable may be used. Next, in FIG. 5B, the data of the output voltage information VS at time t = 1 in FIG. 4 is written to the address [1] of the EEPROM 29 based on the instruction of the arithmetic processing circuit 15. Thereafter, the same operation is repeated, and in FIG. 5C, the data of the output voltage information VS at time t = 20 in FIG. 4 is written in the address [20] of the EEPROM 29 based on the instruction of the arithmetic processing circuit 15. If the usable memory capacity of the EEPROM 29 reaches the limit value, the data of the output voltage information VS at time t = 21 in FIG. 4 is overwritten to the address [0] as shown in FIG. . The data of the output voltage information VS at t = 0 disappears at this time. Next, in FIG. 5E, the data of the output voltage information VS at time t = 22 in FIG. 4 is written to the address [1] of the EEPROM 29, and the same operation is repeated thereafter. With the above writing operation, the latest 20 pieces of output voltage information VS data can always be stored in the EEPROM 29.

  However, when this data is read from the EEPROM 29 at a later time based on the instruction of the arithmetic processing circuit 15, it is not known which address data is the latest, so the address value storing the latest data is separately addressed. Write to [21]. For example, in FIG. 5E, since the latest data is written to the address [1], when the data of the output voltage information VS is written to the address [1], the latest address value (data = 1) is set to the address [21]. Write.

Each storage operation, for example, a period in which the lamp-on signal s ₁ is only a period of the active state High, i.e. performed only for the period in which the discharge lamp 13 is lit, period or a discharge lamp 13 of the Low state has been turned off Stops the save operation. Also lamp-on signal s ₁ is in the state of the active High, if the arithmetic processing circuit 15 is forced off the discharge lamp 13 by detecting any abnormality, until the discharge lamp 13 is turned off and save operation, extinguished After that, the save operation is stopped.

Next, a method for reading the output voltage information VS will be described.
Reading of the output voltage information VS from the EEPROM 29 based on the instruction of the arithmetic processing circuit 15 is performed by serial communication using two lines of data lines and clock lines in the same path as in the case of the writing. Since the communication method in the case of the reading is also a general method such as an I ² C bus format, detailed description is omitted.

  Next, transmission of the output voltage information VS from the arithmetic processing circuit 15 to an external device (not shown) is performed using the RXD terminal 28 and the TXD terminal 27. The RXD terminal 28 and the TXD terminal 27 are communication terminals that perform UART (Universal Asynchronous Receiver Transmitter) communication that is standardly installed in the arithmetic processing circuit 15 that is a microcomputer. The RXD terminal 28 is a command terminal that receives commands from external devices. The reception and TXD terminal 27 transmits a command to an external device. In this case, communication between the arithmetic processing circuit 15 and the external device is performed by determining a command system in advance. For example, when reading one piece of data of the output voltage information VS at the address [0] from the external device, first, a read command (for example, B0H) is transmitted via the RXD terminal 28, and then an address command (for example, 00H) is RXD. When transmitted via the terminal 28, a data command (arbitrary output voltage data) is transmitted from the arithmetic processing circuit 15 side via the TXD terminal 27. Since the specifications of the UART communication itself are general, detailed description thereof will be omitted.

Above, observation of the output voltage information VS of the power control circuit 30, stored, has been described per read, the output current information IS, the output signal TS of the thermistor 32, the observation of the input voltage information VS _2, storage is the same for read .

The output voltage information VS, the output current information IS, if you want to save the output signal TS and the input voltage information VS ₂ of the thermistor 32 at the same time, may be devised address mapping EEPROM 29. For example, t = 0 output voltage information VS data at address [0] of EEPROM 29, t = 0 output current information IS data at address [1], and t = 0 output signal TS data at address [2]. Suppose that the data of the input voltage information VS ₂ of t = 0 is stored in the address [3], and the data of t = 0 is stored in the addresses [0] to [3] of the EEPROM 29. Similarly, t = 1 data is stored at addresses [4] to [7] of the EEPROM 29. This is repeated even after the address [8], and finally, t = 20 data is stored at addresses [76] to [79] of the EEPROM 29. The latest address is stored at the last address [80].

  FIG. 6 shows specific examples of observation data in various failure states of the discharge lamp 13 and the discharge lamp lighting device 80. FIG. 6 shows nine types of failure phenomenon examples, and shows specific value examples for each observation data. There are also different types of failure conditions for each failure phenomenon.

The nine types of failure phenomenon examples will be described below with reference to FIG.
(1) Lamp not lit (all periods)
This phenomenon is a phenomenon in which the lamp does not light up even though the lamp is started from the lamp-off state. There are two types of failure conditions in this phenomenon. One is when the lamp voltage is MAX (for example, 360V) and the overvoltage protection is activated and the discharge lamp 13 does not light, for example, when the internal gas leaks due to a crack in the seal portion of the discharge lamp 13 or the like. Or when the lamp starts immediately after the lamp is turned off (hot start). The other is the case where the input voltage shows an abnormal value and does not light up. The cause is, for example, a case where the input voltage is out of the rated (for example, 250 to 400 V) due to a failure on the main body side of the projection display.

(2) Lamp not lit (after high pressure)
This phenomenon is a phenomenon in which a high voltage pulse is generated by a lamp start from a lamp extinguishing state and the lamp is turned on once, but the lamp is extinguished at the moment when it returns to a normal output voltage. There are two types of failure conditions in this phenomenon. One is when the lamp voltage is MAX (for example, 360V) and the overvoltage protection is activated and does not light up. The cause is, for example, that the AC power cable on the projection display apparatus side is disconnected while the lamp is lit and the discharge lamp There are cases where the power supply of the lighting device is also momentarily interrupted, and a large amount of mercury adheres to the cathode of the discharge lamp 13 or due to a malfunction of the discharge lamp 13. The other is a case where the input voltage shows an abnormal value and does not light up. The cause thereof is, for example, a case where the input voltage is out of a rating (for example, 250 to 400 V) due to a failure on the main body of the projection display.

(3) Lamp extinction during lighting This phenomenon refers to a phenomenon in which the discharge lamp 13 is suddenly extinguished from a state in which it is normally lit. There are three types of failure conditions in this phenomenon. The first is when the overvoltage protection is activated when the lamp voltage of the discharge lamp 13 is 140 V or more, for example, because the lamp electrode is deteriorated due to the life of the discharge lamp 13 and the lamp voltage becomes abnormal. For example, when it rises. The second case is when the input voltage shows an abnormal value. The cause is, for example, when the AC power cable on the projection display apparatus side is disconnected and the input voltage is lowered while the discharge lamp 13 is lit. . Third, the lamp voltage of the discharge lamp 13 is lowered by, for example, 10 to 40 V, and in some cases, the temperature rises and the overheat protection operation is performed. The cause is, for example, when the discharge lamp 13 is abnormally swollen, the internal pressure of the discharge lamp 13 is lowered, and the lamp voltage is lowered. (4) Lamp burst This phenomenon is caused when the discharge lamp 13 is normally lit. A phenomenon that suddenly bursts. There are two types of failure conditions in this phenomenon. One is a case where the overvoltage protection function is activated when the lamp voltage of the discharge lamp 13 becomes 140 V or more from a normal value, for example, when the discharge lamp 13 is ruptured due to a failure of the discharge lamp 13 or the like. It is. The other is a case where the lamp current of the discharge lamp 13 has increased abnormally, for example, when the discharge lamp lighting device 80 becomes uncontrollable due to some failure and an abnormal lamp current flows through the discharge lamp 13. It is.

(5) Low-voltage protection This phenomenon is a phenomenon in which the output voltage value is abnormally lowered and a protection operation is performed. The failure condition of this phenomenon is that the lamp voltage of the discharge lamp 13 is, for example, 10 V or less. In this case, the low voltage protection operation is performed. The cause is, for example, when the electrode of the discharge lamp 13 is short-circuited by mercury and the lamp voltage is abnormally reduced. In the case of this phenomenon, the discharge lamp 13 may be recovered if vibration is applied.

(6) Flicker This phenomenon is a phenomenon in which the brightness fluctuates when the discharge lamp 13 is normally lit. The failure condition of this phenomenon is when the lamp current of the discharge lamp 13 or the pulse current periodically superimposed on the lamp current is reduced, and the cause thereof is, for example, that the discharge lamp lighting device 80 has some failure. This is the case when the pulse current cannot be superimposed.

(7) Heat generation This phenomenon refers to a phenomenon in which the discharge lamp lighting device 80 becomes abnormally hot when the discharge lamp 13 is normally lit. There are two types of failure conditions in this phenomenon. One is when the thermistor 32 detects an abnormal temperature and an overheat protection operation is performed, for example, when the air cooling fan stops. The other is a case where the overheat protection operation is performed as a result of the lamp voltage of the discharge lamp 13 being lowered to 40 V or less, for example, when the discharge lamp 13 itself is defective (lamp failure). .

(8) Output reduction This phenomenon is a phenomenon in which the luminance is lowered in a state where the discharge lamp 13 is normally lit. There are two types of failure conditions in this phenomenon. One is the case where the lamp current of the discharge lamp 13 is low, for example, when the discharge lamp lighting device 80 cannot maintain power due to some failure. The other is a case where the lamp current of the discharge lamp 13 is low and the input voltage is also low. The cause is, for example, a case where the input voltage is lower than the rated (for example, 250 to 400V) due to a failure on the projection type video display device main body side. It is.

(9) Lamp Life This phenomenon refers to a phenomenon in which the output voltage exceeds the upper limit value when the discharge lamp 13 is normally lit. The failure condition of this phenomenon is when the lamp voltage of the discharge lamp 13 is, for example, 120 V or more, and the cause thereof is, for example, when the discharge lamp 13 is in an end state due to its life.

  A system microcomputer (not shown) on the projection-type image display apparatus main body side can analyze each observation data via UART communication, and can determine which fault condition is present by the combination thereof. The determination result of the failure state can be notified to the user by characters or symbols.

  FIG. 7 is a diagram illustrating a display example of a failure state. FIG. 7A shows a case where the failure state is added to the display image. In FIG. 7A, 74 is a screen as a display unit, 70 is a video display region projected and displayed on the screen 74, and 71 is a character display unit superimposed on the video display region 70 by the drive circuit 79. . The character display unit 71 displays a detected failure state indicating “lamp life”. For the display of the failure state, a liquid crystal, an LED, or the like as a display unit is provided in the main body of the projection type video display device, so that, for example, the display as shown in FIG. You may make it perform. In FIG. 7B, reference numeral 40 denotes a binary display type liquid crystal element, which expresses a failure state with numerals. In the example of FIG. 7B, the “lamp life” is “E09”. The display on the main body of the projection type image display device is particularly effective when the discharge lamp 13 cannot be lit, such as “lamp not lit”. As described above, the display of the failure state on the screen 74 or the projection type video display device can be understood by the user who handles the projection type video display device using the discharge lamp lighting device 80 as the cause of the protection operation. It can be easily informed, and is highly useful as a self-diagnosis function of the projection display apparatus. In FIG. No. 1 “Lamp not lit”. Although the cause of “Lamp unlit” in 2 is different, the failure condition may be the same. In such a case, the content of the failure may be displayed in two or more. When the display is divided, for example, in the display method shown in FIG. 7B, the display of “E01” and the display of “E02” may be switched at a certain cycle.

According to the embodiment of the present invention, in the video display device using the discharge lamp lighting device 80, the operation state of the device is analyzed based on the operation information in the period before that including the time when the protection function is activated. Since it can be discriminated, the cause of the protection operation in which the protection function has worked can be easily and accurately investigated.
In the above embodiment, the EEPROM 29 is used as the non-volatile memory. However, the present invention is not limited to this, and other non-volatile memories such as a flash memory may be used. In the configuration of FIG. 2, the EEPROM 29 as a non-volatile memory is provided outside the arithmetic processing circuit 15, but may be incorporated in the arithmetic processing circuit 15. In the above embodiment, detection and storage of the output voltage information VS of the power control circuit 30, the output current information IS of the power control circuit 30, the output signal TS of the thermistor 29, and the input voltage information VS ₂ of the power control circuit 30, Although reading, analysis, and discrimination have been described, the present invention is not limited to this, and other information such as output power may be detected, stored, read, analyzed, and discriminated.

It is a block diagram of the projection type video display apparatus as an Example of this invention. It is an example of a structure of the discharge lamp lighting device as an Example of this invention. It is operation | movement explanatory drawing of the discharge lamp lighting device of FIG. It is a figure which shows the example of an observation result of the output voltage of the electric power control circuit in the discharge lamp lighting device of FIG. It is a figure which shows the example of a mapping procedure of the information preserve | saved at memory. It is explanatory drawing of the various failures in a discharge lamp and a discharge lamp lighting device. It is a figure which shows the example of a display of the failure state in a discharge lamp or a discharge lamp lighting device.

Explanation of symbols

1 ... Power input terminal,
2, 8, 9, 10, 11 ... MOS-FET,
3 ... Diode,
4 ... Choke coil,
5: Capacitor,
6, 7, 12, 33, 34 ... resistors,
13 ... discharge lamp,
14 ... igniter circuit,
15 ... arithmetic processing circuit,
18 ... PWM control circuit,
19, 23 ... ON / OFF signal input terminal,
21, 22 ... drive circuit,
26: Lamp on signal input terminal,
27: Serial data transmission terminal,
28: Serial data receiving terminal,
29… EEPROM,
30: Power control circuit,
31 ... AC conversion circuit,
32 ... Thermistor,
40 ... Liquid crystal element,
70: Video display area,
71 ... character display part,
74 ... Screen,
75: Optical system,
76 ... Video display element,
77 ... Reflector,
79 ... Drive circuit,
80: A discharge lamp lighting device.

Claims (10)

A discharge lamp lighting device for lighting by supplying electric power to a discharge lamp,
A power control circuit that controls and outputs input power; and
An igniter circuit for generating a predetermined high voltage for starting lighting of the discharge lamp;
An arithmetic processing circuit that controls the power control circuit based on output voltage information of the power control circuit and drive current information of the discharge lamp;
A non-volatile memory connected to the arithmetic processing circuit and storing at least one of the output voltage information and the driving current information in a predetermined period based on an instruction of the arithmetic processing circuit;
And after the elapse of the predetermined period, the arithmetic processing circuit reads information stored in the memory and determines a state of the discharge lamp or the discharge lamp lighting device during the predetermined period based on the information. A discharge lamp lighting device characterized by that. A discharge lamp lighting device for lighting by supplying electric power to a discharge lamp,
A power control circuit that controls and outputs input power; and
An igniter circuit for generating a predetermined high voltage for starting lighting of the discharge lamp;
An arithmetic processing circuit that controls the power control circuit based on output voltage information of the power control circuit and drive current information of the discharge lamp;
Temperature detecting means for detecting the temperature of the discharge lamp lighting device and outputting a corresponding signal;
Connected to the arithmetic processing circuit, and based on an instruction of the arithmetic processing circuit, at least one of input voltage information of the power control circuit, output voltage information, driving current information, or output information of the temperature detection means in a predetermined period Non-volatile memory for storing,
The arithmetic processing circuit reads information stored in the memory after the predetermined period, and determines the state of the discharge lamp or the discharge lamp lighting device during the predetermined period based on the information. A discharge lamp lighting device characterized by that.   The said arithmetic processing circuit is the structure which performs bidirectional communication with the external circuit of the said discharge lamp lighting device, and reads the information preserve | saved in the said memory according to the command from this external circuit. The discharge lamp lighting device according to 1.   When the amount of information stored in the memory exceeds a predetermined amount, the arithmetic processing circuit overwrites the latest information with the address of the oldest information, and stores address information indicating the storage location of the latest information in the memory. The discharge lamp lighting device according to claim 1, wherein the discharge lamp lighting device is configured to be stored in the battery.   The discharge lamp lighting device according to claim 1, wherein the arithmetic processing circuit is configured to store the information in the memory only during a period in which the discharge lamp is lit. A discharge lamp lighting device according to any one of claims 1 to 5,
A video display element that modulates light emitted from the discharge lamp lighting device side to form an optical image corresponding to a video signal;
A drive circuit for driving the video display element based on a video signal;
A video display device comprising: A discharge lamp lighting device according to any one of claims 1 to 5,
A video display element that modulates light emitted from the discharge lamp lighting device side to form an optical image corresponding to a video signal;
A driving circuit for driving the video display element based on a video signal or information stored in the memory;
A video display device characterized in that the state of the discharge lamp lighting device during the predetermined period can be displayed based on the information stored in the memory even after the predetermined period has elapsed. A discharge lamp lighting device according to any one of claims 1 to 5,
A display unit for displaying the state of the discharge lamp or the discharge lamp lighting device based on the information stored in the memory;
A video display element that modulates light emitted from the discharge lamp lighting device side to form an optical image corresponding to a video signal;
A drive circuit for driving the video display element based on a video signal;
And a video display device characterized in that the state of the discharge lamp lighting device during the predetermined period can be displayed on the display unit based on the information stored in the memory even after the predetermined period has elapsed. .   As the information stored in the memory, the output voltage information of the power control circuit indicates a maximum voltage value, the driving current information of the discharge lamp indicates a minimum driving current value, and the arithmetic processing circuit performs a protection operation due to an overvoltage. Is displayed, it is highly probable that the cause of the protection operation is a lamp non-lighting due to the malfunction of the discharge lamp. The input voltage information of the power control circuit indicates an abnormal input voltage value. In this case, it is displayed that there is a high possibility that the cause is a lamp non-lighting due to a system abnormality, the output voltage information indicates an output voltage value exceeding a threshold value, and the arithmetic processing circuit performs a protective operation due to overvoltage. If the input voltage information is abnormally reduced, an indication that there is a high possibility that the cause of the protection operation is lamp extinction due to the malfunction of the discharge lamp is displayed. When the pressure value is indicated, a message indicating that the cause is likely to be the extinction of the lamp due to the system abnormality is displayed. The output voltage information indicates a normal value or the output voltage value exceeds the threshold value after the normal value. And when the arithmetic processing circuit performs a protection operation due to an overvoltage, the drive current information is displayed to indicate that the cause of the protection operation is likely to be a lamp rupture due to a failure of the discharge lamp. Indicates an abnormally increased drive current value, the output information of the temperature detection means indicates an output value exceeding a threshold value, and the arithmetic processing circuit performs a protective operation due to overvoltage, the cause of the protective operation is The display indicates that there is a high possibility that the lamp is ruptured due to an abnormality. The output voltage information indicates an output voltage value below a threshold value, and the output information of the temperature detection means indicates an output value exceeding the threshold value. When the arithmetic processing circuit performs a protection operation due to an overvoltage, at least one of indications that the cause of the protection operation is likely to be a lamp extinction due to a lamp failure including a lamp bulge The video display device according to claim 7 or 8, wherein display is possible.   As the information stored in the memory, when the output voltage information of the power control circuit indicates an output voltage value below a threshold value and the arithmetic processing circuit performs a protection operation with a low voltage, the cause of the protection operation is If the drive current information indicates an abnormally reduced drive current value, indicating that there is a high possibility of a bridge phenomenon in the lamp, and if the pulse superimposed current in the memory is abnormally reduced, the cause is A display indicating that the flicker suppression function is degraded due to a ballast abnormality or a system abnormality, the output information of the temperature detection means indicates an output value exceeding a threshold value, and the arithmetic processing circuit performs a protection operation due to overheating. In such a case, a display is made to indicate that the cause of the protection operation is heat generation due to a ballast air cooling abnormality or the like. When the information indicates an output value that exceeds a threshold value and the arithmetic processing circuit performs a protection operation due to overheating, the drive current information is a threshold value that displays that the cause of the protection operation is heat generation due to a lamp failure. When the following drive current values are indicated, a display indicating that there is a high possibility that the cause is an output decrease due to a ballast abnormality is displayed. The drive current information indicates a drive current value that is equal to or less than a threshold value, and the input voltage information Indicates an input voltage value that is less than or equal to the threshold value, a display indicating that there is a high possibility that the cause is a decrease in output due to a system abnormality is performed.If the output voltage information indicates an output voltage value that is equal to or greater than the threshold value, The video display device according to claim 7 or 8, wherein a display indicating that the lamp needs to be replaced because of an abnormality is possible.

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