JP2007147870A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device which displays a high-quality video by superposing specified wavelength light from an auxiliary light source on white light from a white light source so as to compensate for the white light, and does not give an unpleasant feeling to a user because the video where the intensity of the specified wavelength light from the auxiliary light source is high is displayed when the white light source and the auxiliary light source are turned on. <P>SOLUTION: When a projector 1 is started, a control part 20 lights a high-pressure mercury lamp 11 first. If a lighting decision part 21 decides that lighting succeeds, lighting of an LED array 12 where a plurality of LEDs are juxtaposed is started. Lighting of the LED array 12 is controlled to gradually increase light quantity by a method to light it according to a pulse signal while increasing a duty ratio so that a supplied current is gradually increased or to gradually increase the number of lighting LEDs out of a plurality of LEDs. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device such as a projector or a liquid crystal display, and more particularly to a display device including two types of light sources such as a lamp and an LED (Light Emitting Diode).

  Conventionally, a light source such as a halogen lamp, a xenon lamp, or a mercury lamp has been provided, and white light from the light source is light-modulated by a light modulator such as a DMD (Digital Micromirror Device) or a liquid crystal panel to form an image, and the image is displayed on the screen. Projectors for projecting are widely used. However, in the above-described lamp used as a light source, the intensity of red light contained in white light is smaller than the intensity of green light and blue light. Therefore, the intensity of green light and blue light is reduced according to the intensity of red light. Had to be used.

  Patent Document 1 proposes a projector that includes an ultra-high pressure mercury lamp that emits white light and an LED that emits red light, and by reinforcing the intensity of red light by the LED, the light efficiency is good and the color balance is good. Yes. In this projector, the white light from the lamp and the red light from the LED are mixed and irradiated by a dichroic prism, and this light is separated into red light, green light and blue light by a dichroic mirror, and each separated light is separated. Is modulated by a light modulation element, and the light modulated light is synthesized by a cross dichroic prism and projected.

  Patent Document 2 includes a discharge lamp that emits white light and an LED that emits light belonging to a specific wavelength band, and assisting the discharge lamp with light from the LED can improve luminance and color reproducibility. A video display device that can reduce the frequency of replacement of the discharge lamp has been proposed. In this video display device, the light from the discharge lamp and the light from the LED are superimposed by a narrow band filter, the superimposed light is separated by a color filter, and the separated light is optically modulated by a light modulation element. Projected.

In Patent Document 3, a cold cathode tube having three wavelengths and an arrayed LED are used in combination as a reading light source, so that a portion where the luminous intensity is discontinuous like a point light source is eliminated, and the illuminance before lighting is increased. There has been proposed an image forming apparatus and an image scanning method capable of preventing a variation and performing reading by illuminating the original with an illuminance suitable for reading an image of the original.
JP 2004-264512 A Japanese Patent Laying-Open No. 2005-250088 JP-A-2005-65198

  However, since the projector described in Patent Literature 1 and the video display device described in Patent Literature 2 include different types of light sources, when the devices are activated and the light sources are turned on, the lighting of each light source is completed. There is a problem that the time required for is different. For example, a mercury lamp requires a time of about several minutes until the light quantity is stabilized after activation, but the light quantity of LED is stabilized immediately after activation. In the case of the image forming apparatus described in Patent Document 3, it is only necessary to start reading a document after the light quantity of the cold cathode tube is stabilized. However, in a display device such as a projector, an LED belongs to a specific wavelength band. In the case of emitting light, for example, red light, an image displayed immediately after startup is an image with a strong red component, and the user may feel uncomfortable. This problem can be solved by preventing the image from being displayed until the amount of light from the mercury lamp stabilizes. However, since the image cannot be displayed for a few minutes after the device starts up, the convenience of the device is reduced. There is a risk of getting worse. In addition, the life of a mercury lamp is about several thousand hours, and the life of an LED is more than tens of thousands of hours. Therefore, when the life of the mercury lamp is exhausted, the mercury lamp does not turn on, and only the red light of the LED is used. An image is displayed, which may cause discomfort to the user.

  Furthermore, a lamp used as a light source has a usage time exceeding a certain level, and there is a risk of explosion if the lamp is further used. If the lamp bursts, there is a danger that the user may be injured when replacing the lamp, so the projector is equipped with a protection function that prevents the lamp from being turned on if it is used for a certain period of time. ing. When the lamp cannot be lit due to the protection function, for example, in order to prompt the user to replace the lamp, for example, a warning lamp provided in the main body of the projector is often lit. However, the projector may be used while being fixed to the ceiling or wall of the room. In this case, there is a problem that it is difficult to visually recognize the warning light.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a white light source as a light source and an auxiliary light source that emits light in a specific wavelength region, and the light source is activated when the apparatus is started up. When the light source is turned on, the auxiliary light source is turned on by controlling the amount of increase in the amount of light from the auxiliary light source so that the amount of light increased in accordance with the time required until the amount of light from the white light source is stabilized. An object of the present invention is to provide a display device that can be used.

  Another object of the present invention is that when the auxiliary light source emits light of a light amount corresponding to the amount of electricity supplied, for example, an LED whose light amount changes according to the amount of supplied current, An object of the present invention is to provide a display device that can easily control the light amount of the auxiliary light source by controlling the amount of current supplied to the light source to control the light amount of the auxiliary light source.

  Another object of the present invention is to easily control the light amount of the auxiliary light source by increasing the light amount by turning on the auxiliary light source by pulse control while increasing the duty ratio. An object of the present invention is to provide a display device that can perform the above-described operation.

  Another object of the present invention is that when the auxiliary light source is composed of a plurality of light emitting elements, the control is performed so as to gradually increase the number of light emitting elements to be lit. An object of the present invention is to provide a display device that can easily control the amount of light of an auxiliary light source.

  Another object of the present invention is to detect the temperature of the white light source and increase the amount of light of the auxiliary light source according to the detected temperature, so that the temperature dependence of the time until the light amount of the white light source becomes stable is determined. It is an object to provide a display device that can turn on an auxiliary light source in consideration of the above.

  Another object of the present invention is that it is possible to determine whether or not the white light source is turned on, and when the light source is not turned on, the auxiliary light source is not turned on so that the white light source is not turned on due to the lifetime. It is an object of the present invention to provide a display device that can prevent only an auxiliary light source from being turned on.

  Another object of the present invention is to make it possible to determine whether or not the white light source is lit, and to display a notification image using only the light of the auxiliary light source when the white light source is not lit. Another object of the present invention is to provide a display device capable of notifying the user that the white light source has expired and is no longer lit.

  Another object of the present invention is to count the time during which the white light source is lit during use of the device, and to prevent the white light source from being turned on when the lighting time exceeds a predetermined time. An object of the present invention is to provide a display device capable of preventing the lamp from being used for a certain period of time or longer and bursting when the light source is a lamp, for example.

  A display device according to the present invention includes a white light source and an auxiliary light source that emits light in a specific wavelength region, and displays the image formed by modulating the light from the white light source and the auxiliary light source. In addition, when the white light source and the auxiliary light source are turned on, a lighting control unit that turns on the auxiliary light source while controlling the amount of increase in the amount of light is provided.

  In the present invention, the auxiliary light source is turned on while controlling the amount of increase in the light amount of the auxiliary light source. For example, when a mercury lamp is provided as a white light source and an LED that emits red light is provided as an auxiliary light source, the mercury lamp requires several minutes to complete lighting, and accordingly, the light intensity of the LED gradually increases. It is turned on so as to prevent an image with a strong red component from being displayed when the apparatus is activated.

  In the display device according to the present invention, the auxiliary light source emits light having a light amount corresponding to the amount of electricity supplied, and the lighting control unit controls the amount of electricity supplied to the auxiliary light source. It is characterized by being.

  In the present invention, when the auxiliary light source emits light with a light amount corresponding to the amount of electricity supplied, for example, when the LED changes in light amount according to the current amount, the amount of current supplied to the LED is controlled. Thus, it is possible to easily control the light quantity of the LED in accordance with the amount of increase in light quantity when a white light source, for example, a mercury lamp is turned on.

  Further, the display device according to the present invention is characterized in that the lighting control means performs lighting by intermittently supplying power to the auxiliary light source while increasing a duty ratio.

  In the present invention, when an auxiliary light source, for example, an LED is lit by pulse control, so-called PWM (Pulse Width Modulation) control, the “H” time of the pulse gradually increases from the start of LED lighting. The control is performed so as to increase the duty ratio. The LED light quantity can be easily controlled, and it is suitable when the LED is controlled by the PWM method even after the lighting is completed.

  The display device according to the present invention is characterized in that the auxiliary light source has a plurality of light emitting elements, and the lighting control means increases the number of lighting of the plurality of light emitting elements. .

  In the present invention, when the auxiliary light source is an aggregate of a plurality of LEDs, for example, control is performed so as to gradually increase the number of LEDs to be lit. The light quantity of the auxiliary light source can be easily controlled, and it is suitable when more LEDs are mounted to increase the light quantity of the auxiliary light source.

  In addition, the display device according to the present invention includes a detection unit that detects the temperature of the white light source, and the lighting control unit increases the light amount of the auxiliary light source according to a detection result of the detection unit. It is characterized by.

  In the present invention, the temperature of the white light source is detected, and lighting is performed by increasing the amount of light of the auxiliary light source according to the detected temperature. For example, when the mercury lamp is turned on after it is turned off, the light quantity increase characteristic after the start of lighting changes and the time required for lighting changes, so the increase in the light quantity of the LED is changed according to the temperature, Correspond to changes in characteristics due to temperature of white light source.

  In addition, a display device according to the present invention includes a white light source and an auxiliary light source that emits light in a specific wavelength region, and displays an image formed by modulating the light from the white light source and the auxiliary light source. A determination unit that determines whether the white light source can be turned on in the apparatus; and a lighting control unit that controls the auxiliary light source not to be turned on when the determination unit determines that the white light source cannot be turned on. It is characterized by providing.

  In the present invention, for example, when the white light source is a mercury lamp, it is possible to determine whether or not the lighting is successful by attempting to turn on the mercury lamp and measuring the current or voltage amount of the mercury lamp after a few seconds. When the mercury lamp is not turned on, the auxiliary light source is not turned on. When the auxiliary light source is, for example, an LED that emits red light, the mercury lamp is not lit, only the LED is lit, and there is no possibility that an image of only the red light source is displayed.

  In addition, a display device according to the present invention includes a white light source and an auxiliary light source that emits light in a specific wavelength region, and displays an image formed by modulating the light from the white light source and the auxiliary light source. A determination unit configured to determine whether the white light source can be turned on, and a lighting control unit configured to control the auxiliary light source to be turned on when the determination unit determines that the white light source cannot be turned on. And means for modulating the light from the auxiliary light source to form and display a notification image.

  In the present invention, when the white light source is not turned on, the auxiliary light source is turned on, and a notification image is displayed using only the light from the auxiliary light source. When the auxiliary light source is an LED that emits red light, for example, the notification image is displayed in red, so that the notification can be effectively performed to the user.

  In addition, the display device according to the present invention includes a timing unit that measures the lighting time of the white light source, and the white light source is not turned on when the lighting time of the white light source exceeds a predetermined time. Features.

  In the present invention, the lighting time of the white light source is counted, and the white light source is not lit when the accumulated lighting time exceeds a predetermined time. When the white light source is, for example, a mercury lamp, the usage time exceeds a certain level, and there is a risk of explosion if the usage continues further, but this can be prevented.

  According to the present invention, when the white light source and the auxiliary light source are turned on at the time of starting the display device, the light source is turned on while controlling the amount of increase in the light amount of the auxiliary light source until the light amount of the white light source is stabilized. The auxiliary light source can be turned on with an increase in the amount of light in accordance with the required time, and it is possible to prevent an image with a strong red component from being displayed when the device starts up. Unpleasant feeling can be prevented, and the display quality of the display device can be improved.

  Further, in the case of the present invention, when the auxiliary light source emits light with a light amount corresponding to the amount of electricity supplied, for example, when the LED changes in light amount according to the current amount, the amount of current supplied to the LED By controlling the lighting, it is possible to easily control the light quantity of the LED according to the amount of increase in the light quantity when the white light source, for example, a mercury lamp is lit, so that a strong red component image is displayed. This can be prevented more easily.

  In the case of the present invention, the auxiliary light source is turned on by pulse control while increasing the duty ratio to increase the light amount. Since it is possible to easily control the amount of light, it is possible to more easily prevent an image with a strong red component from being displayed.

  In the case of the present invention, when the auxiliary light source is composed of a plurality of light emitting elements, the white light source is turned on by controlling the number of light emitting elements to be gradually increased. Since the amount of light of the auxiliary light source can be easily controlled in accordance with the amount of increase in the amount of light at the time, it is possible to more easily prevent an image with a strong red component from being displayed.

  Further, according to the present invention, the temperature of the white light source is detected, and the light amount of the auxiliary light source is increased according to the detected temperature, so that the auxiliary light source is dependent on the temperature dependence of the time until the light amount of the white light source is stabilized. The light source can be turned on and the display of images with a strong red component can be prevented more reliably, thus preventing the user from feeling uncomfortable when viewing images with a strong red component. it can.

  Further, according to the present invention, it is possible to determine whether or not the white light source is turned on, and when the light source is not turned on, the auxiliary light source is not turned on, so that only the auxiliary light source is turned on when the white light source is not turned on. For example, when the auxiliary light source is an LED that emits red light, it is possible to prevent the user from feeling uncomfortable by displaying an image using only red light, and to improve the display quality of the display device. .

  Further, according to the present invention, it is possible to determine whether or not the white light source is turned on. When the white light source is not turned on, only the light from the auxiliary light source is used to display a notification image. For example, in the case of an LED that emits red light, the notification video is displayed in red, so that the user can be effectively notified and the user can be urged to replace the white light source with certainty.

  According to the present invention, the white light source is, for example, a lamp by counting the lighting time of the white light source and not turning on the white light source when the accumulated lighting time exceeds a predetermined time. In this case, since it is possible to prevent the lamp from being used and bursting for a certain period of time, there is no risk that the user will be injured by replacing the broken lamp, and the safety of the display device can be improved.

(Embodiment 1)
Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof. In the present embodiment, a projector will be described as an example of a display device. FIG. 1 is a block diagram showing a configuration of a projector according to Embodiment 1 of the present invention. In the figure, reference numeral 1 denotes a projector, which modulates light from a light source based on a video signal supplied from a DVD player 101 which is an external playback device, and projects the light onto a screen 102.

  The projector 1 includes, as a light source, a high-pressure mercury lamp 11 that emits white light and an LED array 12 in which a plurality of LEDs that emit red light are arranged side by side. From the high-pressure mercury lamp 11 whose red component is weaker than the green and blue components. By supplementing the white light with the red light from the LED array 12, it is possible to improve the quality, such as color purity and luminance, of the image displayed on the screen 102. White light from the high-pressure mercury lamp 11 and red light from the LED array 12 are superimposed by the dichroic prism 13 and collected on the color wheel 14.

  The color wheel 14 is a disk in which three fan-shaped color filters that respectively transmit red, green, and blue light are equally arranged, and a rotation shaft of a motor (not shown) is connected to the center. By rotating the color wheel 14 by a motor, the light from the dichroic prism 13 is transmitted in a certain period, for example, in the order of red, green, and blue, and the white light has three light components having a red component, a green component, or a blue component. Can be separated.

  The light separated by the color wheel 14 is incident on a light modulation unit 15 having a light modulation element such as a DMD or a liquid crystal panel. The light modulation unit 15 modulates incident light according to a control signal supplied from the control unit 20 described later to form an image. An image formed by the light modulator 15 is enlarged by the projection lens 16 and projected onto the screen 102.

  The projector 1 also includes an input unit 24 having an input terminal connected to the DVD player 101 via a cable. The input unit 24 supplies the video signal input from the DVD player 101 to the control unit 20. It is. Based on the video signal given from the input unit 24, the control unit 20 controls a light modulation element such as a DMD or a liquid crystal panel provided in the light modulation unit 15 to form a video.

  Further, the projector 1 includes a lamp driving unit 23 that generates a driving voltage necessary for lighting the high-pressure mercury lamp 11 and supplies the driving voltage to the high-pressure mercury lamp 11, and the lamp driving unit 23 is supplied from the control unit 20. The high-pressure mercury lamp 11 is driven and lit by a drive command. Since the high-pressure mercury lamp 11 cannot be turned on when the inside of the lamp is at a high temperature, the high-pressure mercury lamp 11 cannot be turned on after it has been used for a certain period of time and cannot be turned on immediately thereafter. If the lamp drive unit 23 continues to apply a voltage in such a state that it cannot be lit, there is a risk that the life of the high-pressure mercury lamp 11 will be deteriorated. Whether or not the high-pressure mercury lamp 11 has been successfully lit can be determined by examining the current or voltage of the high-pressure mercury lamp 11 a few seconds after the lamp drive unit 23 attempts to illuminate. This determination is made to give a determination result to the control unit 20. When the lighting of the high-pressure mercury lamp 11 fails, the control unit 20 given the determination result stops applying the driving voltage by the lamp driving unit 23 and is sufficient for the temperature of the high-pressure mercury lamp 11 to decrease. After waiting for a time, a driving command is given again to the lamp driving unit 23 to try to light it again.

  The projector 1 also includes an LED drive unit 22 for driving a plurality of LEDs of the LED array 12. The LED drive unit 22 is controlled by the control unit 20 to turn on the LED while adjusting the amount of drive current supplied to the LEDs of the LED array 12. The LEDs of the LED array 12 are easier to control the amount of light than the high-pressure mercury lamp 11, and can control the amount of light by adjusting the amount of drive current.

  The LEDs of the LED array 12 require a sufficiently short time to complete the lighting as compared with the high-pressure mercury lamp 11, and the high-pressure mercury lamp 11 and the LED array 12 are simultaneously turned on to control the current amount of the LED array 12. If not, there is a risk that an image with a strong red component is projected in the initial stage of lighting. In particular, when lighting of the high-pressure mercury lamp 11 fails and re-lighting is attempted, only a red image is projected, so that the user may feel uncomfortable. For this reason, after the lighting of the high-pressure mercury lamp 11 is successful, the control unit 20 lights the LED array 12 while gradually increasing the amount of light of the LED array 12.

  FIG. 2 is a graph showing the light amounts of the high-pressure mercury lamp 11 and the LED array 12 when the projector 1 according to the present invention is activated. In the drawing, the high pressure mercury lamp 11 is illustrated in the case where the lighting is completed without failing to light. The case where the LED array 12 is turned on simultaneously with the high-pressure mercury lamp 11 and the amount of light is not controlled is indicated by a broken line in the figure.

  As shown in FIG. 2, when the high-pressure mercury lamp 11 and the LED array 12 are turned on simultaneously, the LED array 12 is turned on immediately after the start of lighting, and the amount of white light emitted by the high-pressure mercury lamp 11 in the initial lighting period. There is a period in which the amount of red light emitted from the LED array 12 is larger. During this period, an image with a very strong red component is projected onto the screen 102. Thereafter, the amount of white light from the high-pressure mercury lamp 11 is greater than the amount of red light from the LED array 12, but since the ratio of red light is high until the amount of light from the high-pressure mercury lamp 11 is stabilized, the red component is slightly stronger. Is projected onto the screen 102.

  Therefore, in the present invention, the control unit 20 starts lighting the high-pressure mercury lamp 11, and after several seconds have elapsed (time t1), the lighting determination unit 21 for lighting the high-pressure mercury lamp 11 determines success or failure. When the lighting is successful, a drive command is given to the LED drive unit 22 so as to start lighting the LED array 12. Further, the amount of light supplied to the LED array 12 is adjusted so that the amount of light gradually increases, and further, the amount of light reaches a maximum amount at or near the time (time t2) when the amount of light of the high-pressure mercury lamp 11 is stabilized. Is lit up. Thereby, from the initial stage of lighting of the high-pressure mercury lamp 11, an image with good color purity in which the red component is supplemented by the LED array 12 can be projected without projecting an image with a strong red component.

  The amount of increase in the amount of light of the LED array 12 per predetermined time is determined in advance according to the lighting characteristics of the high-pressure mercury lamp 11 measured in advance, and is stored in a memory such as an EEPROM (not shown) provided in the control unit 20 or a flash memory. Remember. When the LED array 12 is lit, the control unit 20 reads the amount of increase in the amount of light from the memory and controls the LED driving unit 22 in accordance with this.

  FIG. 3 is a flowchart showing a processing procedure of a light source lighting process performed by the control unit 20 when the projector 1 according to the first embodiment of the present invention is activated. After the power is turned on to the projector 1 by the user, the control unit 20 first gives a driving command to the lamp driving unit 23 to turn on the high pressure mercury lamp (step S1). Then, it waits for several seconds (step S2), and it is investigated by the lighting determination part 21 whether lighting of the high pressure mercury lamp 11 was successful (step S3). Note that the standby time is measured using a timer (not shown) provided in the control unit 20.

  When the lighting of the high-pressure mercury lamp 11 has failed (S3: NO), it is checked whether or not the lighting of the high-pressure mercury lamp 11 has failed more than a predetermined number of times (step S4). Note that the number of times lighting has failed is performed using a counter (not shown) provided in the control unit 20. When lighting has failed more than the predetermined number of times (S4: YES), the control unit 20 ends the process. If the number of failed lighting is not equal to or greater than the predetermined number (S4: NO), the system waits for several tens of seconds (step S5), waits until the temperature of the high pressure mercury lamp 11 decreases, returns to step S1, and returns to the high pressure mercury lamp 11 Lights up.

  If the high-pressure mercury lamp 11 has been successfully lit in step S3 (S3: YES), a drive command is given to the LED drive unit 22 to start lighting the LED array 12 (step S6). Time is measured by a timer provided in the control unit 20 to check whether or not a fixed time has passed (step S7). If the fixed time has not passed (S7: NO), the fixed time has passed. Wait until. After a predetermined time has elapsed (S7: YES), the amount of current supplied to the LED array 12 is increased according to a predetermined amount of increase in current (step S8). Thereafter, it is checked whether or not the light amount of the LED array 12 has reached the maximum amount and the lighting of the LED array 12 is completed (step S9). If not completed (S9: NO), the process returns to step S7. Increase the supply current amount repeatedly. When the lighting of the LED array 12 is completed (S9: YES), the control unit 20 ends the process.

  In the projector 1 having the above configuration, the lighting start timing of the high-pressure mercury lamp 11 and the LED array 12 is shifted, the amount of light is adjusted by adjusting the supply current to the LED array 12, so that the red component is A strong image is projected onto the screen 102, and the user can be prevented from feeling uncomfortable. In addition, when the high pressure mercury lamp 11 fails to be lit, the processing is terminated without turning on the LED array 12, so that the LED array 12 can be turned off when the high pressure mercury lamp 11 does not illuminate due to the lifetime. It is possible to prevent a red-only image formed by only red light from being projected onto the screen 102.

  In the present embodiment, the projector has been described as an example of the display device. However, the present invention is not limited to this. For example, a liquid crystal display is provided with two types of light sources such as a cold cathode tube and an LED. However, the same configuration can be applied. Moreover, although the lighting start timing of the high pressure mercury lamp 11 and the LED array 12 is shifted and the lighting of the LED array 12 is started after the lighting determination of the high pressure mercury lamp 11 is performed, the present invention is not limited to this. The LED array 12 may start to be turned on at the same timing, or the high-pressure mercury lamp 11 starts to be turned on, the timer is timed, and the LED array 12 is turned on after a certain time has elapsed. It may be. Further, the LED array 12 may be turned on before the high-pressure mercury lamp 11 and the image projection is not performed until the high-pressure mercury lamp 11 is successfully turned on.

  Moreover, although the structure which presets the increase amount of the electric current supplied to the LED array 12 was shown, it is not restricted to this, For example, the optical sensor which detects the light quantity of the high pressure mercury lamp 11 is mounted, The amount of current supplied to the LED array 12 may be determined according to the detection result. In this case, the ratio between the light amount of the high-pressure mercury lamp 11 and the light amount of the LED array 12 is substantially constant. By adjusting the light quantity of the LED array 12, the LED array 12 can be utilized most efficiently.

  Further, although the high pressure mercury lamp 11 is used as the white light source, the present invention is not limited to this, and other lamps such as a high pressure sodium lamp or a metal hydride lamp may be used. Moreover, although it was set as the structure which uses LED as an auxiliary light source, it is not restricted to this, The structure which uses another light emitting element may be sufficient. The configuration of the optical path from the high-pressure mercury lamp 11 and the LED array 12 to the screen 102 is not limited to that shown in FIG.

(Modification 1)
FIG. 4 is a block diagram showing a configuration of a projector according to Modification 1 of Embodiment 1 of the present invention. The projector 1a according to the first modification is configured to drive the LED array 12 by the PWM method, and includes a pulse signal generation unit 31 that generates a pulse signal for driving the LED array 12. The pulse signal generation unit 31 generates a square pulse signal according to the drive command given from the control unit 20a and gives it to the LED array 12, and adjusts the length of the "H" period of the square pulse signal, the so-called duty ratio. By doing so, the amount of red light emitted from the LED array 12 is adjusted. The control unit 20a performs the lighting process of the high-pressure mercury lamp 11 and the LED array 12 in the same procedure as the flowchart shown in FIG. 3 when the projector 1a is started up. In step S8, the control unit 20a performs the process of increasing the current amount. Instead, the process of increasing the length of the “H” period of the square pulse signal generated by the pulse signal generation unit 31 is performed to increase the amount of light of the LED array 12.

(Modification 2)
FIG. 5 is a block diagram showing a configuration of a projector according to Modification 2 of Embodiment 1 of the present invention. The projector 1b according to the second modification is configured such that a plurality of LEDs arranged in parallel in the LED array 12b can be individually driven and lit by the LED driving unit 22b. The LED driving unit 22b individually supplies current to the plurality of LEDs, and sequentially drives the plurality of LEDs to light up in accordance with a driving command given from the control unit 20b. The control unit 20b performs the lighting process of the high-pressure mercury lamp 11 and the LED array 12b in the same procedure as the flowchart shown in FIG. 3 when the projector 1b is started up. Instead, a process for increasing the number of LEDs lit in the LED array 12b is performed to increase the light quantity of the LED array 12b.

(Modification 3)
FIG. 6 is a circuit diagram showing the configuration of the LED lighting mechanism of the projector according to Modification 3 of Embodiment 1 of the present invention. The control unit 20c of the projector according to the modification 3 gives a 1-bit drive command for determining whether to turn on / off the LED array 12 (only one LED is shown in FIG. 6) to the LED drive unit 22c. Only the lighting / non-lighting timing of the LED array 12 is controlled. The LED drive unit 22c includes a current source Is that generates a drive current and a switch SW that switches supply / non-supply of the drive current. When an instruction to turn on the LED array 12 is given from the control unit 20c, the switch The drive current is supplied to the LED array 12 by switching the SW. Each LED of the LED array 12 is configured such that the output of the LED driving unit 22c is connected to the anode side to be supplied with driving current, and the cathode side is grounded via a resistor R and a capacitor C connected in parallel. Connected to potential. As a result, the rise of the drive current from the LED drive unit 22c is delayed according to the time constant determined by the resistance value of the resistor R and the capacitance value of the capacitor C, so the time until the light amount of the LED array 12 reaches the maximum amount is reduced. Can be extended. By appropriately determining the resistance value of the resistor R and the capacitance value of the capacitor C according to the time until the light amount of the high-pressure mercury lamp 11 is stabilized in advance, the LED array 12 is matched to the light amount of the high-pressure mercury lamp 11. The amount of light can be increased.

(Embodiment 2)
FIG. 7 is a block diagram showing a configuration of the projector according to Embodiment 2 of the present invention. The projector 41 according to Embodiment 2 includes a temperature sensor 43 that detects the temperature of the high-pressure mercury lamp 11 or its surroundings. The high-pressure mercury lamp 11 is difficult to turn on when the ambient temperature is low, and the time required to stabilize the light amount becomes long. For this reason, when the temperature sensor 43 detects the temperature and gives a detection result to the control unit 42, and the control unit 42 controls the LED driving unit 22 according to the detection result and turns on the LED array 12, the amount of increase in light amount Is adjusted.

  FIG. 8 is a graph showing the light amounts of the high-pressure mercury lamp 11 and the LED array 12 when the projector 41 according to Embodiment 2 of the present invention is started. In the drawing, the high pressure mercury lamp 11 is illustrated in the case where the lighting is completed without failing to light. Moreover, the case where the temperature around the high pressure mercury lamp 11 is high is indicated by a solid line, and the case where the temperature is low is indicated by a one-dot chain line.

  As shown in FIG. 8, when the ambient temperature is low, the high-pressure mercury lamp 11 takes more time to stabilize the light intensity than when the temperature is high. For this reason, the control unit 42 performs lighting while adjusting the increase amount of the light amount of the LED array 12 according to the temperature. For example, when the temperature is high, the light amount of the LED array 12 is maximized at time t2. The amount of light is increased, and when the temperature is low, the amount of light is increased so that the amount of light of the LED array 12 becomes maximum at time t3 later than time t2. Note that the amount of increase in the light amount of the LED array 12 per predetermined time is determined in advance according to the lighting characteristics and temperature characteristics of the high-pressure mercury lamp 11 measured in advance, and an EEPROM or flash memory (not shown) provided in the control unit 20 or the like. Store it in the memory. When the LED array 12 is lit, the control unit 20 reads the amount of increase in the amount of light from the memory and controls the LED driving unit 22 in accordance with this.

  FIG. 9 is a flowchart showing a light source lighting process performed by the control unit 42 when the projector 41 according to the second embodiment of the present invention is activated. After the power is turned on to the projector 41 by the user, the control unit 42 first gives a driving command to the lamp driving unit 23 to turn on the high-pressure mercury lamp (step S21). Then, it waits for several seconds (step S22), and it is investigated by the lighting determination part 21 whether lighting of the high pressure mercury lamp 11 was successful (step S23).

  If lighting of the high-pressure mercury lamp 11 has failed (S23: NO), it is checked whether lighting of the high-pressure mercury lamp 11 has failed more than a predetermined number of times (step S24). When lighting has failed more than a predetermined number of times (S24: YES), the control part 42 complete | finishes a process. If the number of failed lighting is not equal to or greater than the predetermined number (S24: NO), the system waits for several tens of seconds (step S25), waits until the temperature of the high-pressure mercury lamp 11 decreases, returns to step S21, and returns to the high-pressure mercury lamp 11 Lights up.

  If the high-pressure mercury lamp 11 has been successfully lit in step S23 (S23: YES), a drive command is given to the LED drive unit 22 to start lighting the LED array 12 (step S26). Time is measured by a timer provided in the control unit 42 to check whether or not a fixed time has passed (step S27). If the fixed time has not passed (S27: NO), the fixed time has passed. Wait until. After a predetermined time has elapsed (S27: YES), the temperature sensor 43 detects the temperature of the high-pressure mercury lamp 11 or its surroundings (step S28), and supplies it to the LED array 12 according to the amount of current increase corresponding to the detected temperature. The amount of current is increased (step S29). Thereafter, it is checked whether or not the light amount of the LED array 12 reaches the maximum amount and the lighting of the LED array 12 is completed (step S30). If not completed (S30: NO), the process returns to step S27. The temperature detection and the increase in supply current are repeated. When the lighting of the LED array 12 is completed (S30: YES), the control unit 42 ends the process.

  In the projector 41 having the above configuration, since the temperature sensor 43 is provided, the lighting speed of the LED array 12 that is the auxiliary light source can be adjusted according to the temperature dependency of the lighting speed of the high-pressure mercury lamp 11 that is the white light source. An image with a strong red component is reliably projected onto the screen 102 when the projector 41 is activated, and the user can be prevented from feeling uncomfortable.

  In the second embodiment, the projector 41 is described as an example of the display device. However, the display device is not limited to this, and the display device may be a liquid crystal display including a cold cathode tube and an LED as a light source, for example. In this case, since the cold cathode tube has less self-heating than the high-pressure mercury lamp and is easily influenced by the ambient temperature, the above-described configuration including the temperature sensor is preferable. The lighting start timing of the LED array 12 is the same regardless of the temperature, but is not limited to this, and the lighting start timing of the LED array 12 may be changed according to the detection result of the temperature sensor 43.

  Since the other configuration of the projector according to the second embodiment is the same as the configuration of the projector according to the first embodiment, the corresponding portions are denoted by the same reference numerals and detailed description thereof is omitted.

(Modification)
FIG. 10 is a circuit diagram showing a configuration of an LED lighting mechanism of a projector according to a modification of the second embodiment of the present invention. The control unit 42d of the projector according to the modified example gives a 1-bit drive command for determining whether to turn on / off the LED array 12 (only one LED is shown in FIG. 10) to the LED drive unit 22d. Only the lighting / non-lighting timing of the LED array 12 is controlled. The LED drive unit 22d includes a current source Is that generates a drive current and a switch SW that switches supply / non-supply of the drive current. When an instruction to turn on the LED array 12 is given from the control unit 42d, the switch The drive current is supplied to the LED array 12 by switching the SW. Each LED of the LED array 12 is connected to the output of the LED drive unit 22d on the anode side and supplied with a drive current. In addition, the resistor R and the thermistor Rth and the capacitor C connected in series are connected in parallel between the cathode of the LED array 12 and the ground potential.

  The thermistor Rth is an element whose resistance value changes according to the temperature. The higher the temperature, the smaller the resistance value. The thermistor Rth is disposed in the vicinity of the high-pressure mercury lamp 11 and is used as an element for detecting the temperature of the high-pressure mercury lamp 11. Thereby, since the resistance value of the thermistor Rth decreases at a high temperature, the time constant due to the resistor R, the thermistor Rth, and the capacitance C becomes small, and the LED array 12 has the maximum amount of light in a short time. Further, since the resistance value of the thermistor Rth increases at low temperatures, the time constant increases, and the time until the light quantity of the LED array 12 becomes maximum is delayed from that at high temperatures. Therefore, the time until the light quantity of the LED array 12 becomes maximum can be adjusted in accordance with the temperature change around the high-pressure mercury lamp 11.

(Embodiment 3)
FIG. 11 is a block diagram showing a configuration of a projector according to Embodiment 3 of the present invention. The control unit 52 of the projector 51 according to the third embodiment includes a lighting time measuring unit 53 for measuring the cumulative usage time of the high pressure mercury lamp 11 and a lighting prohibition flag 54 for determining whether the high pressure mercury lamp 11 can be turned on. And are provided. The lighting time measuring unit 53 is a so-called counter, and is capable of counting thousands of hours that is the life of the high-pressure mercury lamp 11. Further, the lighting time timer 53 does not lose the counted time even when the power of the projector 51 is turned off, and resets the time measured when the high-pressure mercury lamp 11 is replaced. It is.

  The lighting prohibition flag 54 is set to “1” when the time counted by the lighting time timer 53 reaches a predetermined time, and is set to “0” when the high-pressure mercury lamp 11 is replaced. It is like that. The lighting prohibition flag 54 is provided in a non-volatile memory such as a flash memory or an EEPROM provided in the control unit 52 so that the value is not initialized even when the power of the projector 51 is turned off. is there.

  FIG. 12 is a flowchart showing a light source lighting process performed by the control unit when the projector according to Embodiment 3 of the present invention is activated. After the power is turned on to the projector 51 by the user, the control unit 52 first checks whether or not the lighting prohibition flag 54 is set to “1” (step S41), and sets the lighting prohibition flag 54 to “1”. If yes (S41: YES), the controller 52 ends the process without turning on the high-pressure mercury lamp 11 and the LED array 12. When the lighting prohibition flag 54 is not set to “1”, that is, when it is set to “0” (S41: NO), the control unit 52 gives a driving command to the lamp driving unit 23 to increase the pressure. The mercury lamp is turned on (step S42), then waits for a few seconds (step S43), and the lighting determination unit 21 checks whether the high-pressure mercury lamp 11 has been turned on successfully (step S44).

  If lighting of the high-pressure mercury lamp 11 has failed (S44: NO), it is checked whether lighting of the high-pressure mercury lamp 11 has failed more than a predetermined number of times (step S45). When lighting has failed more than the predetermined number of times (S45: YES), the control unit 52 ends the process without lighting the high-pressure mercury lamp 11 and the LED array 12. If the number of failed lighting is not equal to or greater than the predetermined number (S45: NO), the system waits for several tens of seconds (step S46), waits until the temperature of the high-pressure mercury lamp 11 decreases, returns to step S42, and returns to the high-pressure mercury lamp 11 Lights up.

  If the high-pressure mercury lamp 11 has been successfully lit in step S44 (S44: YES), the lighting time counting unit 53 starts timing (step S47), gives a drive command to the LED drive unit 22, and the LED Lighting of the array 12 is started (step S48). Next, the timer provided in the controller 52 is used to check whether or not a certain time has elapsed (step S49). If the certain time has not elapsed (S49: NO), the certain time has elapsed. Wait until it has passed. After a predetermined time has elapsed (S49: YES), the amount of current supplied to the LED array 12 is increased according to a predetermined amount of current increase (step S50). Thereafter, it is checked whether or not the light amount of the LED array 12 reaches the maximum amount and the lighting of the LED array 12 is completed (step S51). If not completed (S51: NO), the process returns to step S49. Increase the supply current amount repeatedly. When the lighting of the LED array 12 is completed (S51: YES), the control unit 52 ends the process. Note that the timing by the lighting time timer 53 is continued until the high-pressure mercury lamp 11 is turned off.

  In the projector having the above configuration, when the high-pressure mercury lamp 11 is used for a certain period of time or longer, the high-pressure mercury lamp 11 is prohibited from being lit, so that the possibility of the high-pressure mercury lamp 11 bursting can be eliminated. Further, since the LED array 12 is not turned on when the high pressure mercury lamp 11 is used for a predetermined time or longer and lighting is prohibited, or when the lighting of the high pressure mercury lamp fails, the screen 102 is not turned on. It is possible to prevent the display of only red video.

  Since the other configuration of the projector according to the third embodiment is the same as the configuration of the projector according to the first embodiment, the corresponding parts are denoted by the same reference numerals and detailed description thereof is omitted.

(Embodiment 4)
FIG. 13 is a flowchart showing a processing procedure of a light source lighting process performed by the control unit when the projector according to Embodiment 4 of the present invention is started. After the power is turned on to the projector by the user, the control unit first gives a driving command to the lamp driving unit 23 to turn on the high-pressure mercury lamp (step S61). Then, it waits for several seconds (step S62), and it is investigated by the lighting determination part 21 whether the lighting of the high pressure mercury lamp 11 was successful (step S63).

  If lighting of the high-pressure mercury lamp 11 has failed (S63: NO), it is checked whether lighting of the high-pressure mercury lamp 11 has failed more than a predetermined number of times (step S64). If the lighting fails more than the predetermined number of times (S64: YES), the control unit lights the LED array 12 (step S65). The lighting of the LED array 12 at this time is performed so that the amount of light is maximized in a short period without adjusting the amount of current to be supplied. Next, a notification image is formed by the light modulation unit 15, and the notification image is projected from the projection lens 16 onto the screen 102 (step S66). As a result, a red notification image formed only by the red light emitted from the LED array 12 is projected onto the screen 102. The notification video displays, for example, a message such as “Lamp life has expired” or “Replace lamp” to the user.

  In step S64, when the number of failed lighting is not the predetermined number or more (S64: NO), the process waits for several tens of seconds (step S67), waits until the temperature of the high-pressure mercury lamp 11 decreases, and returns to step S61. The high pressure mercury lamp 11 is turned on.

  If the high-pressure mercury lamp 11 has been successfully turned on in step S63 (S63: YES), a drive command is given to the LED drive unit 22 to start lighting the LED array 12 (step S68). Time is measured by a timer provided in the control unit to check whether or not a certain time has elapsed (step S69). When the certain time has not elapsed (S69: NO), until the certain time has elapsed. stand by. After a predetermined time has elapsed (S69: YES), the amount of current supplied to the LED array 12 is increased according to a predetermined amount of current increase (step S70). Thereafter, it is checked whether the light amount of the LED array 12 reaches the maximum amount and the lighting of the LED array 12 is completed (step S71). If not completed (S71: NO), the process returns to step S69. Increase the supply current amount repeatedly. When the lighting of the LED array 12 is completed (S71: YES), the control unit ends the process.

  In the projector having the above configuration, when the high-pressure mercury lamp 11 has reached the end of its life and can no longer be lit, a notification image can be displayed to the user, so that the replacement of the high-pressure mercury lamp 11 can be urged. Further, since the notification image is formed by the red light from the LED array 12, the user is highly likely to recognize it as a highly urgent warning, and the replacement of the high-pressure mercury lamp 11 can be urged more reliably. Note that, similarly to the projector 51 according to the third embodiment, the projector according to the fourth embodiment also measures the lighting time of the high-pressure mercury lamp 11, and when the lighting time exceeds a certain time, the high-pressure mercury lamp 11 In this case, a notification image by the red light of the LED array 12 may be displayed.

  Since the other configuration of the projector according to the fourth embodiment is the same as that of the projector according to the first embodiment, the corresponding portions are denoted by the same reference numerals and detailed description thereof is omitted.

It is a block diagram which shows the structure of the projector which concerns on Embodiment 1 of this invention. It is a graph which shows the light quantity of the high pressure mercury lamp at the time of projector starting based on this invention, and an LED array. It is a flowchart which shows the process sequence of the lighting process of the light source which a control part performs at the time of starting of the projector which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the projector which concerns on the modification 1 of Embodiment 1 of this invention. It is a block diagram which shows the structure of the projector which concerns on the modification 2 of Embodiment 1 of this invention. It is a circuit diagram which shows the structure of the lighting mechanism of LED of the projector which concerns on the modification 3 of Embodiment 1 of this invention. It is a block diagram which shows the structure of the projector which concerns on Embodiment 2 of this invention. It is a graph which shows the light quantity of the high pressure mercury lamp at the time of projector starting based on Embodiment 2 of this invention, and an LED array. It is a flowchart which shows the process sequence of the lighting process of the light source which a control part performs at the time of starting of the projector which concerns on Embodiment 2 of this invention. It is a circuit diagram which shows the structure of the lighting mechanism of LED of the projector which concerns on the modification of Embodiment 2 of this invention. It is a block diagram which shows the structure of the projector which concerns on Embodiment 3 of this invention. It is a flowchart which shows the process sequence of the lighting process of the light source which a control part performs at the time of starting of the projector which concerns on Embodiment 3 of this invention. It is a flowchart which shows the process sequence of the lighting process of the light source which a control part performs at the time of starting of the projector which concerns on Embodiment 4 of this invention.

Explanation of symbols

1, 1a, 1b Projector 11 High pressure mercury lamp (white light source)
12, 12b LED array (auxiliary light source)
13 Dichroic prism 14 Color wheel 15 Light modulation unit 16 Projection lens 20, 20a, 20b, 20c Control unit 21 Lighting determination unit (determination unit)
22, 22b, 22c, 22d LED drive unit 23 Lamp drive unit 24 Input unit 31 Pulse signal generation unit 41 Projector 42, 42d Control unit 43 Temperature sensor (detection means)
51 Projector 52 Control Unit 53 Lighting Time Timer (Timer)
54 Lighting prohibition flag

Claims (8)

In a display device that includes a white light source and an auxiliary light source that emits light in a specific wavelength region, and displays an image formed by modulating the light from the white light source and the auxiliary light source,
A display device comprising: a lighting control unit that lights the auxiliary light source while controlling the amount of increase in light amount when the white light source and the auxiliary light source are turned on. The auxiliary light source emits light of a light amount corresponding to the amount of electricity supplied,
The display device according to claim 1, wherein the lighting control unit controls an amount of electricity supplied to the auxiliary light source.   The display device according to claim 1, wherein the lighting control unit performs lighting by intermittently supplying power to the auxiliary light source while increasing a duty ratio. The auxiliary light source has a plurality of light emitting elements,
The display device according to claim 1, wherein the lighting control unit increases the number of lighting of the plurality of light emitting elements. Detecting means for detecting the temperature of the white light source;
The display device according to claim 1, wherein the lighting control unit increases a light amount of the auxiliary light source according to a detection result of the detection unit. In a display device that includes a white light source and an auxiliary light source that emits light in a specific wavelength region, and displays an image formed by modulating the light from the white light source and the auxiliary light source,
Determining means for determining whether the white light source can be turned on;
A display device comprising: a lighting control unit that controls the auxiliary light source not to be lit when it is determined by the determination unit that the white light source cannot be lit. In a display device that includes a white light source and an auxiliary light source that emits light in a specific wavelength region, and displays an image formed by modulating the light from the white light source and the auxiliary light source,
Determining means for determining whether the white light source can be turned on;
A lighting control means for controlling the auxiliary light source to be turned on when it is determined by the determining means that the white light source cannot be turned on;
A display device comprising: means for modulating light from the auxiliary light source to form and display a notification image. Comprising a time measuring means for measuring the lighting time of the white light source,
The display device according to claim 6 or 7, wherein when the lighting time of the white light source exceeds a predetermined time, the white light source is not turned on.

Images