JP2006011085A - Projector and reverse connection preventing circuit for projector lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector which detects reverse connection of a DC lamp for the projector and prevents the DC lamp from being damaged, or minimizes the damage, when the reverse connection is detected. <P>SOLUTION: The projector comprises a power source device Ge for supplying the DC lamp 1 with driving power; a control microcomputer Mc for controlling the power source device; a reverse connection detecting circuit 7 for detecting a voltage between the DC lamp 1 and the power source Ge; and a reverse connection warning lamp WL connected to the control microcomputer Mc. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a reverse connection prevention device for a projector and a projector lamp.

In recent years, projectors that project images by irradiating light onto a screen are often used for presentations, home theaters, and the like. There are a plurality of different projectors such as a projection method on a screen.

As an example of the plurality of types of projectors, the structure of the projector will be described based on a projector using DLP (Digital Light Processing) (registered trademark) technology. FIG.
Shows a schematic layout of a projector using DLP (registered trademark) technology. A projector A shown in FIG. 1 includes a direct-current lamp 1 that is a light source, a light tunnel 2 that equalizes the light intensity of light emitted from the light source, a color wheel 3 that sequentially polarizes light into the wavelengths of RGB components, A DMD (Digital Micromirror Device) (registered trademark) 4 that reflects light, a light absorption plate 5, and a projection lens 6 are included. Although a white lamp is used here as the light source, a light source that emits light having light of all the RGB wavelengths can be widely used besides the white lamp.

The operation of the projector A is as follows. The light emitted from the DC lamp 1 passes through the light tunnel 2 that equalizes the light intensity and is irradiated on the color wheel 3. Color wheel 3
Is rotating at a high speed and a constant speed, and the light applied to the color wheel 3 passes through any of the R / G / B regions. At this time, the light transmitted through the R region is polarized into light having a red wavelength, and G
The light transmitted through the region is polarized into light having a green wavelength, and the light transmitted through the region B is polarized into light having a blue wavelength. DMD (registered trademark) 4 is continuously irradiated with light of each color wavelength.

The DMD (registered trademark) 4 reflects the irradiated light in a predetermined direction, and reflects necessary light among the red, green, and blue wavelengths passing through the color wheel 3 to the projection lens 6. Then, unnecessary things are reflected on the light absorbing plate 5. The light incident on the projection lens 6 is magnified and irradiated and displayed on the screen Sc. The color wheel 3 rotates at a high speed as described above, and DMD
When light of RGB wavelengths selectively reflected by (registered trademark) 4 is sequentially irradiated on the screen, the human eye combines light of each wavelength of RGB corresponding to the amount of reflection of DMD (registered trademark) 4. Recognize as a finished color.

In the above example, a projector using DMD (registered trademark) has been described as an example, but there are many other types of projectors that have the same light source as a projector using DMD (registered trademark). To do.
Japanese Patent Laid-Open No. 9-230501

The direct current lamp, which is the light source used in the projector, is a consumable item, and as the degree of wear increases, the display quality deteriorates and changes in the amount of generated heat appear. Don't be.

However, the DC lamp has a polarity, and when the polarity is reversed, an abnormal arc occurs in the DC lamp, and the amount of light emitted from the DC lamp is not stable. The electrode of the DC lamp is damaged, and excessive damage is caused.

Further, the DC lamp is a consumable item, and the projector is designed on the assumption that the DC lamp is replaced, and is configured to physically prevent reverse connection by a connector shape or the like. However, in the manufacturing process, connection mistakes are likely to occur due to line recombination, jig repair, etc., and even if physically connected in the forward direction, it may be electrically connected in the reverse direction.

Therefore, the present invention detects a reverse connection of a direct current lamp for a projector, and when the reverse connection is detected, the direct current lamp is not damaged or the damage can be minimized. An object is to provide a connection detection circuit.

The present invention also provides a projector and a projector lamp capable of improving the reliability of the product by detecting reverse connection of the DC lamp for the projector at the time of manufacture and minimizing damage to the DC lamp. An object of the present invention is to provide a reverse connection detection circuit.

In order to achieve the above object, the invention according to claim 1 is a DC lamp as a light source, a light tunnel that equalizes the light intensity of light emitted from the DC lamp, and an R / G / B color filter. Are arranged in a disk shape, DMD (registered trademark) including a reflection plate that reflects light transmitted through the color wheel, a light absorption plate that absorbs light, and a projection that projects light onto a screen A projector having a lens, a power supply device that supplies driving power to the DC lamp, a control microcomputer that controls the power supply device, and a reverse connection detection circuit that detects reverse connection of the lamp, The reverse connection detection circuit detects a change in voltage in the power supplied from the power supply device to the DC lamp, and transmits the voltage value to the control microcomputer. A power supply line between the power supply device and the DC lamp is connected via a capacitor, and a resistor to which an input signal from the capacitor is input is connected to one end thereof, and an anode side electrode is connected to the other end of the resistor A cathode side electrode is connected to a connection node between the diode, a capacitor having one end connected to the cathode side electrode of the diode and the other end grounded, and a connection node between the cathode side electrode of the diode and one end of the capacitor And a Zener diode whose anode side electrode is grounded, the connection node is connected to the control microcomputer, and the control microcomputer uses a voltage inputted from the reverse connection detection circuit as a predetermined voltage. When the power supply exceeds a predetermined time, a reverse connection warning lamp attached to the projector main body is turned on, and the power supply is To provide a projector, characterized in that stops the power supply to the DC lamp than location.

According to this configuration, the voltage of the driving power supplied from the power supply device to the DC lamp is detected. This makes it possible to determine at the same time when the power is turned on whether the DC lamp is reversely connected. Further, when a transient change in voltage exceeds a certain value, the warning lamp is turned on, and then the supply of power to the DC lamp is stopped after a predetermined time. Even when the DC lamp is reversely connected, it is possible to prevent the DC lamp from becoming seriously damaged by continuing the reverse connection state for a long time.

In order to achieve the above object, the invention according to claim 2 is directed to a projector that projects a predetermined image on the screen by irradiating the screen with light, wherein the projector is a DC lamp as a light source, and the DC A power supply device that supplies driving power to the lamp; a control microcomputer that controls the power supply device; and a reverse connection detection circuit that detects reverse connection of the lamp, wherein the reverse connection detection circuit A change in voltage in the power supplied from the power supply device to the DC lamp is detected, and the voltage value is transmitted to the control microcomputer, and the reverse connection detection circuit is configured to supply power between the power supply device and the DC lamp. Connected to the supply line via a capacitor, one end of which is connected to a resistor to which an input signal from the capacitor is input, and the other end of the resistor is connected to an anode side electrode A diode, a capacitor having one end connected to the cathode side electrode of the diode and the other end grounded, and a cathode side electrode connected to a connection node between the cathode side electrode of the diode and one end of the capacitor and an anode A side electrode of which is grounded, and the connection node is connected to the control microcomputer, and the control microcomputer has a voltage input from the reverse connection detection circuit exceeding a predetermined voltage. A reverse connection warning lamp attached to the projector main body is lit, and supply of power from the power supply device to the DC lamp is stopped after a predetermined time has elapsed.

According to this configuration, it is possible to detect reverse connection of the DC lamp of the projector using the DC lamp. It is possible to instantly detect and warn that the DC lamp is reversely connected. As a result, even if the DC lamp is reversely connected due to an error in wiring or the like, the fact that the reverse connection is detected at the same time as turning on the power is detected, a warning and the power supply are stopped, thereby reducing damage to the DC lamp. be able to.

In order to achieve the above-described object, the invention according to claim 3 is a projector that projects a predetermined image on the screen by irradiating the screen with light, and the projector is a direct-current lamp that is a light source; A power supply device that supplies driving power to the DC lamp; a control microcomputer that controls the power supply device; and a reverse connection detection circuit that detects reverse connection of the lamp, the reverse connection detection circuit Is a peak hold circuit, detects a change in voltage in the power supplied from the power supply device to the DC lamp, and transmits the voltage value to the control microcomputer, the control microcomputer is the reverse connection detection circuit When the input voltage exceeds a predetermined voltage, the reverse connection warning lamp attached to the projector main body is turned on, and the power supply device To provide a projector, characterized in that stops the power supply to the DC lamp.

According to this configuration, since the existing peak hold circuit is adopted as the reverse connection detection circuit, it is not necessary to design a new circuit for the reverse connection detection circuit, and accordingly, the manufacturing cost can be reduced. it can.

In order to achieve the above object, the invention according to claim 4 includes: a direct-current lamp that is a light source; a power supply device that supplies driving power to the direct-current lamp; and a control microcomputer that controls the power supply device. A reverse connection detection circuit for detecting reverse connection of the lamp provided in a projector for projecting a predetermined image on the screen by irradiating light on the screen, the DC lamp from the power supply device The voltage change in the power supplied to the power supply is detected, and the voltage value is transmitted to the control microcomputer, and is connected to the power supply line between the power supply device and the DC lamp via a capacitor. A resistor to which an input signal from the capacitor is input to one end, a diode having an anode side electrode connected to the other end of the resistor, and one end to the cathode side electrode of the diode And a capacitor having the other end grounded, and a Zener diode having a cathode side electrode connected to a connection node between the cathode side electrode of the diode and one end of the capacitor, and an anode side electrode grounded And providing a reverse connection detection circuit for a projector lamp, wherein the connection node is connected to the control microcomputer.

According to this configuration, the reverse connection of the DC lamp provided in the projector can be detected by detecting the voltage at a predetermined position of the projector by the reverse connection detection circuit. Thus, the reverse connection of the DC lamp can be detected simultaneously or substantially simultaneously with the turning on of the projector.

In order to achieve the above-mentioned object, the invention according to claim 5 includes a DC lamp as a light source, a power supply device that supplies driving power to the DC lamp, and a control microcomputer that controls the power supply device. A reverse connection detection circuit for detecting reverse connection of the lamp provided in a projector for projecting a predetermined image on the screen by irradiating light on the screen, the DC lamp from the power supply device There is provided a reverse connection detection circuit for a projector lamp, comprising a peak hold circuit that detects a change in voltage in the power supplied to the power supply and transmits the voltage value to a control microcomputer.

According to this configuration, an existing peak hold circuit is employed as the reverse connection detection circuit, so that it is not necessary to design a circuit for detecting a new voltage, and the manufacturing cost can be reduced accordingly.

According to the present invention, when the reverse connection of a direct current lamp for a projector is detected and the reverse connection is detected, the direct current lamp is not damaged or the damage can be minimized.

According to the present invention, the reverse connection of the direct current lamp for the projector at the time of manufacture is detected at an early stage,
By minimizing the damage to the DC lamp, the reliability of the product can be enhanced.

The best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 shows a schematic diagram of an example of a projector according to the present invention. A projector A shown in FIG. 1 includes a direct-current lamp 1 that outputs light, and a light tunnel 2 that equalizes the light intensity of the light emitted from the direct-current lamp 1.
A transmissive liquid crystal filter 3 that polarizes the light emitted from the light tunnel 2 to a wavelength of any of RGB colors when the light is transmitted, and a reflection that reflects the light transmitted through the liquid crystal filter 3 DMD (registered trademark) 4 having a large number of plates, light absorbing plate 5 for irradiating unnecessary light out of light reflected by DMD (registered trademark) 4, and DMD (registered trademark) 4 And a projection lens 6 for enlarging the reflected light and projecting it onto the screen Sc.

The projection operation of the projector A is as follows. First, the light emitted from the white lamp 1 passes through the light tunnel 2 to equalize the light intensity, and is then applied to the liquid crystal filter 3.
The light transmitted through the liquid crystal filter 3 is reflected by the DMD (registered trademark) 4, and light necessary for projecting an image is irradiated on the projection lens 6, and unnecessary light is irradiated on the light absorbing plate 5. The light irradiated on the projection lens 6 is enlarged and irradiated on the screen Sc, whereby an image is projected on the screen Sc.

FIG. 2 shows a layout of the power supply unit of the projector according to the present invention. The power supply unit Ps shown in FIG. 2 supplies a power supply device Ge that supplies driving power to the DC lamp 1, a control microcomputer Mc that controls the power supply device, and a voltage between the DC lamp 1 and the power supply device Ge. It has a reverse connection detection circuit 7 for detecting, and a reverse connection warning lamp WL connected to the control microcomputer Mc. The control microcomputer Mc also controls the reflection angle of the DMD (registered trademark) 4.

The reverse connection detection circuit 7 is connected via a first capacitor 8 to a power supply line SL that supplies driving power from the power supply device Ge to the DC lamp 1. The end portion to which the first capacitor 8 is not connected is connected to the control microcomputer Mc. The reverse connection detection circuit 7 detects the voltage of power supplied from the power supply device Ge to the DC lamp 1. The first capacitor 8 is
In order to prevent a current from flowing directly to the reverse connection detection circuit 7 from the power supply line SL, it is attached.

FIG. 3 is a graph showing a change in voltage of the DC lamp, and FIG. 4 is a block diagram showing an example of a reverse connection detection circuit according to the present invention.

The projector A uses a power supply device G so that the amount of light emitted from the DC lamp 1 is constant.
A driving voltage is supplied to the DC lamp 1 from e. When the DC lamp 1 is connected without making a mistake in polarity, as shown in FIG. 3, the power supplied from the power supply device Ge to the DC lamp 1 is supplied at a substantially constant voltage. However, when the polarity of the DC lamp 1 is reversed, an abnormal arc is generated at the electrode in the DC lamp 1, so that the voltage supplied from the power supply device Ge to the DC lamp 1 is not stable (see FIG. 3).

Paying attention to this unstable voltage, the reverse connection detection circuit 7 detects the voltage supplied to the DC lamp 1 from the power supply device Ge. The reverse connection detection circuit 7 shown in FIG. 4 has a resistor 71 to which an input signal (voltage) from the first capacitor 8 is input, and an anode-side electrode at the end of the resistor 71 opposite to where the first capacitor 8 is attached. A diode 72 connected to 72a, a second capacitor 73 having one end connected to the cathode-side electrode 72c of the diode 72 and the other end installed, a cathode-side electrode 72c of the diode 73 and one end of the second capacitor 73; The connection node Dn has a cathode side electrode 74c connected thereto and an anode side electrode 74a grounded. The connection node Dn is a control microcomputer M.
connected to c.

When power is supplied to the DC lamp 1 from the power supply device Ge, a potential difference (voltage) is generated in the first capacitor 8. Due to this potential difference, a current flows through the resistor 71 and charges are accumulated in the second capacitor 73 via the diode 72. The voltage of the second capacitor 73 at this time is output as an output signal to the control microcomputer Mc.

For example, when the DC lamp 1 is connected in the positive direction (when a constant voltage is applied as shown in FIG. 3), a current flows through the resistor 71 and is accumulated in the second capacitor 73 after power is supplied. The charge of the second capacitor 73 increases from the power supply device Ge to the DC lamp 1.
When the voltage is the same as the voltage of the power supplied to, no current flows through the resistor 71. At this time, even if the voltage supplied to the DC lamp 1 from the power supply device Ge decreases, the diode 7
Since 2 is installed, the second capacitor 73 is not discharged, and the second capacitor holds the highest voltage applied so far.

If the DC lamp 1 is connected in the reverse direction and the voltage rises and falls transiently as shown in FIG. 3, the voltage of the first capacitor 8 is larger than the voltage held by the second capacitor 73 A current is generated in the resistor 71, and electric charges are accumulated in the second capacitor 73. Thereby, the heating of the second capacitor 73 rises. Thereafter, as described above, the voltage of the second capacitor 73 does not drop even when the voltage of the power supplied from the power supply device Ge drops.

When the voltage of the second capacitor 73 becomes higher than a predetermined voltage, a signal indicating that the voltage of the second capacitor 73 is higher than a certain value is output to the control microcomputer Mc. The control microcomputer Mc supplies power to the reverse connection warning lamp WL to light the reverse connection warning lamp WL. Further, after a certain time has elapsed, a power control signal is output to the power supply device Ge, and the driving power supplied to the DC lamp 1 from the power supply device Ge is stopped.

In addition, when the applied reverse voltage exceeds a certain level, the Zener diode 74 causes a current to flow from the cathode side electrode 74c to the anode side electrode 74a. When the voltage held by the second capacitor 73 exceeds a certain level, The electric charge accumulated in the second capacitor 73 is discharged through the Zener diode 74. As a result, the voltage of the second capacitor 73 does not rise above a certain voltage.

As described above, the second capacitor 73 maintains a transient voltage rise that occurs when the DC lamp 1 is reversely connected, and sends the voltage as a signal to the control microcomputer Mc. It is possible to prevent an increase in damage due to the reverse connection of the DC lamp 1 by stopping the supply.

In the above-described embodiment, an example in which a reverse connection detection circuit is applied to a projector using DMD (registered trademark) is described as an example. However, the present invention is not limited to this, and a direct current as a light source such as a liquid crystal projector is used. A projector using a lamp can be widely adopted.

The reverse connection detection circuit described above is not limited to the one described above, and can detect and hold the maximum value of the driving power voltage from the power supply device Ge to the DC lamp 1 such as a peak hold circuit, for example. Can be widely adopted.

Further, in the above-described embodiment, in order to notify that the reverse connection is established, a lamp that turns on the reverse connection warning lamp is adopted. However, the present invention is not limited to this. The method can be widely adopted.

It is a schematic layout diagram of an example of a projector. It is an arrangement plan of an example of a power supply unit used in the projector according to the present invention. It is a graph which shows the voltage change of the drive electric power of this DC lamp when a DC lamp is connected to a forward direction and a reverse direction. It is a block diagram of an example of the reverse connection detection circuit used for the electric power supply part shown in FIG.

Explanation of symbols

A Projector 1 DC lamp 2 Light tunnel 3 Color wheel 4 DMD (registered trademark)
5 Light Absorbing Plate 6 Projection Lens 7 Reverse Connection Prevention Circuit 71 Resistor 72 Diode 73 Second Capacitor 74 Zener Diode 8 First Capacitor Sc Screen Pc Power Supply Unit Ge Power Supply Device Mc Control Microcomputer SL Power Supply Line

Claims (5)

A direct current lamp as a light source;
A light tunnel that equalizes the light intensity of the light emitted from the DC lamp;
A color wheel in which R / G / B color filters are arranged in a disk shape;
DMD (registered trademark) provided with a reflector that reflects the light transmitted through the color wheel;
A light absorbing plate that absorbs light;
A projection lens that projects light onto the screen;
A power supply device for supplying driving power to the DC lamp;
A control microcomputer for controlling the power supply device;
A projector having a reverse connection detection circuit for detecting reverse connection of a lamp,
The reverse connection detection circuit detects a change in voltage in the power supplied from the power supply device to the DC lamp, and transmits the voltage value to a control microcomputer.
The reverse connection detection circuit is connected to a power supply line between the power supply device and the DC lamp via a capacitor, and has a resistor to which an input signal from the capacitor is input at one end, A node having an anode-side electrode connected to the end, a capacitor having one end connected to the cathode-side electrode of the diode and the other end grounded, and a connection node between the cathode-side electrode of the diode and one end of the capacitor A cathode side electrode is connected to the anode side electrode and the zener diode is grounded, and the connection node is connected to the control microcomputer;
The control microcomputer turns on a reverse connection warning lamp attached to the projector body when the voltage input from the reverse connection detection circuit exceeds a predetermined voltage, and after the elapse of a certain time, the direct current from the power supply device A projector characterized in that the supply of power to the lamp is stopped. A projector that projects a predetermined image on a screen by irradiating light on the screen,
The projector has a direct current lamp as a light source,
A power supply device for supplying driving power to the DC lamp;
A control microcomputer for controlling the power supply device;
A reverse connection detection circuit that detects reverse connection of the lamp,
The reverse connection detection circuit detects a change in voltage in the power supplied from the power supply device to the DC lamp, and transmits the voltage value to a control microcomputer.
The reverse connection detection circuit is connected to a power supply line between the power supply device and the DC lamp via a capacitor, and has a resistor to which an input signal from the capacitor is input at one end, A node having an anode-side electrode connected to the end, a capacitor having one end connected to the cathode-side electrode of the diode and the other end grounded, and a connection node between the cathode-side electrode of the diode and one end of the capacitor A cathode side electrode is connected to the anode side electrode and the zener diode is grounded, and the connection node is connected to the control microcomputer;
The control microcomputer turns on a reverse connection warning lamp attached to the projector body when the voltage input from the reverse connection detection circuit exceeds a predetermined voltage, and after the elapse of a certain time, the direct current from the power supply device A projector characterized in that the supply of power to the lamp is stopped. A projector that projects a predetermined image on a screen by irradiating light on the screen,
The projector has a direct current lamp as a light source,
A power supply device for supplying driving power to the DC lamp;
A control microcomputer for controlling the power supply device;
A reverse connection detection circuit that detects reverse connection of the lamp,
The reverse connection detection circuit is a peak hold circuit, detects a change in voltage in power supplied from the power supply device to the DC lamp, and transmits the voltage value to a control microcomputer,
The control microcomputer turns on a reverse connection warning lamp attached to the projector body when the voltage input from the reverse connection detection circuit exceeds a predetermined voltage, and after the elapse of a certain time, the direct current from the power supply device A projector characterized in that the supply of power to the lamp is stopped. A DC lamp as a light source, a power supply device that supplies driving power to the DC lamp, and a control microcomputer that controls the power supply device. A reverse connection detection circuit for detecting reverse connection of the lamp provided in a projector that projects onto the screen,
Detecting a change in voltage in the power supplied from the power supply device to the DC lamp, and transmitting the voltage value to a control microcomputer;
A power supply line between the power supply device and the DC lamp is connected via a capacitor, a resistor to which an input signal from the capacitor is input at one end, and an anode side electrode connected to the other end of the resistor A cathode side electrode is connected to a connection node between the diode, a capacitor having one end connected to the cathode side electrode of the diode and the other end grounded, and a connection node between the cathode side electrode of the diode and one end of the capacitor And a Zener diode whose anode electrode is grounded, and the connection node is connected to the control microcomputer. A DC lamp as a light source, a power supply device that supplies driving power to the DC lamp, and a control microcomputer that controls the power supply device. A reverse connection detection circuit for detecting reverse connection of the lamp provided in a projector that projects onto the screen,
A reverse connection detection circuit for a projector lamp, comprising: a peak hold circuit that detects a change in voltage in power supplied from the power supply device to the DC lamp and transmits the voltage value to a control microcomputer.

Images