JP2015129783A - Image display device, projector, and control method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To derive power/light intensity characteristics in a short measurement time to accurately control a light source.SOLUTION: An image display device emitting image light representing an image to display an image includes: a light source; a light source control unit that controls power supply to the light source on the basis of power/light intensity characteristics indicating the relationship between the power supply and the intensity of light; an image light emitting unit that emits image light by using the light emitted from the light source; a light intensity measurement unit that measures the intensity of light emitted from the light source; and a power/light intensity characteristic derivation unit that derives the power/light intensity characteristics on the basis of the measurement of light intensity measured by the light intensity measurement unit. The light source control unit controls so that the power supply to the light source to sequentially change to a part of a plurality of powers in order in a predetermined range of power to be used; the light intensity measurement unit measures the light intensity for each of the plurality of powers; and the power/light intensity characteristic derivation unit derives power/light intensity characteristics in the range of power to be used on the basis of the light intensity measurement for each of the plurality of powers.

Description

  The present invention relates to an image display device, a projector, and a control method thereof.

  2. Description of the Related Art In recent years, image display devices such as projectors and televisions have been developed that use a semiconductor light source such as a laser diode (LD) or a light emitting diode (LED) or a light source called a solid light source. .

  Patent Document 1 discloses an example of an image display device using a semiconductor light source. In this image display device, the power supplied to the light source is controlled so that the light amount of the light source light gradually changes, and the light amount of the light source light gradually changing according to this is measured to obtain light amount data. The power / light quantity characteristics are derived. In order to display an image with a desired light quantity even when a light source device including a light source deteriorates with time or changes in environment, at least one of light source light and image light is displayed based on the derived power / light quantity characteristics. Adjusting the amount of light (also referred to as “light control”) is disclosed.

JP 2009-145844 A

  In order to display an image with a desired light amount even when the light source device deteriorates with time or changes in the environment, ideally, the light amount is measured for all the supplied powers within the dimming range, and the power / It is desirable to derive the light quantity characteristic. In addition, an error occurs in the light quantity measurement value due to the influence of the response characteristics and temperature characteristics of the optical element such as the light source and the optical sensor for measuring the light quantity. It is required to secure a measurement time considering characteristics and response characteristics. However, if the measurement time in consideration of temperature characteristics and response characteristics is ensured for all the supplied power in the dimming range, the total measurement time becomes long, which significantly impedes the convenience for the user. There is a problem.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to an aspect of the present invention, an image display device that emits image light representing an image and displays the image is provided. The image display device includes: a light source; a light source control unit that controls supply power to the light source based on a power / light quantity characteristic indicating a relationship between supply power and light quantity; and using light emitted from the light source, An image light emitting unit that emits the image light; a light amount measuring unit that measures the amount of light emitted from the light source; and power / a light amount characteristic that derives the power / light amount characteristic based on a light amount measurement value by the light amount measuring unit. A light quantity characteristic deriving unit. The light source control unit controls the power supplied to the light source to sequentially change to a plurality of powers in a part of a predetermined range of power scheduled to be used; The power / light quantity characteristic deriving unit derives the power / light quantity characteristic in the range of power to be used based on the light quantity measurement value for each of the plurality of electric powers. According to the image display apparatus of this aspect, the power / light quantity characteristic can be derived with high accuracy in a short measurement time, and the light source can be controlled with high accuracy using this.

(2) In the image display device according to the above aspect, among the plurality of powers, the maximum power is power for intermittently lighting the light source, and at least some power other than the maximum power is power for continuously lighting the light source. Yes; when the supplied power is the maximum power, the light source control unit controls the supplied power to be intermittent supply corresponding to the intermittent lighting; The light quantity at the time of intermittent lighting by intermittent supply may be measured, and the measured light quantity measurement value may be converted to the light quantity assumed at the time of continuous lighting. In this way, it is possible to derive the power / light quantity characteristics by measuring the light quantity with a plurality of common powers regardless of continuous lighting or intermittent lighting, and the measurement time can be shortened. It is possible to increase the sex.

(3) The image display device according to the above aspect includes at least a temperature measurement unit that measures the temperature of the light source; the light amount measurement unit corrects the light amount measurement value based on the temperature measurement value by the temperature measurement unit. It may be. In this way, it is possible to derive with high accuracy the power / light quantity characteristics in a predetermined range of power scheduled to be used from the light quantity measurement values of some of the plurality of electric powers.

(4) The image display device according to the above aspect includes a plurality of the light sources; the light amount measurement unit measures a light amount emitted from each light source; and the light source control unit includes light emitted from each light source. The power supply is adjusted so that the amount of light is balanced; among the plurality of powers, the maximum power is power for intermittently lighting the light source, and at least some power other than the maximum power is for the light source. The power to be continuously lit; the balance adjustment amount of the supplied power may be set based on the light quantity measurement value at the maximum power among the powers other than the maximum power. In this way, it is possible to adjust the light quantity balance of a plurality of light sources with high accuracy.

(5) According to another aspect of the invention, a projector is provided. The projector includes: a light source; a light source control unit that controls supply power to the light source based on a power / light quantity characteristic indicating a relationship between supply power and light amount; and a light modulation unit that modulates light emitted from the light source A projection optical system that projects light modulated by the modulation unit; a light amount measurement unit that measures the amount of light emitted from the light source; and the power / light amount based on a light amount measurement value by the light amount measurement unit A power / light quantity characteristic deriving unit for deriving the characteristic. The light source control unit controls the power supplied to the light source to sequentially change to a plurality of powers in a part of a predetermined range of power scheduled to be used; The power / light quantity characteristic deriving unit derives the power / light quantity characteristic in the range of power to be used based on the light quantity measurement value for each of the plurality of electric powers. According to the projector of this embodiment, the power / light quantity characteristic can be derived with high accuracy in a short measurement time, and the light source can be controlled with high accuracy using this.

(6) In the projector of the above aspect, among the plurality of electric powers, the maximum electric power is electric power for intermittently lighting the light source, and at least a part of electric power other than the maximum electric power is electric power for continuously lighting the light source; The light source control unit controls the supply power to be intermittent supply corresponding to the intermittent lighting when the supply power is the maximum power; the light amount measurement unit is configured to intermittently supply the maximum power. It is also possible to measure the amount of light during intermittent lighting and convert the measured light amount value to the amount of light assumed during continuous lighting. In this way, it is possible to derive the power / light quantity characteristics by measuring the light quantity with a plurality of common powers regardless of continuous lighting or intermittent lighting, and the measurement time can be shortened. It is possible to increase the sex.

(7) The projector according to the aspect described above includes at least a temperature measurement unit that measures the temperature of the light source; and the light amount measurement unit corrects the light amount measurement value based on the temperature measurement value by the temperature measurement unit. Also good. In this way, it is possible to derive with high accuracy the power / light quantity characteristics in a predetermined range of power scheduled to be used from the light quantity measurement values of some of the plurality of electric powers.

(8) The projector according to the above aspect includes a plurality of the light sources; the light amount measurement unit measures a light amount emitted from each light source; and the light source control unit includes a light amount emitted from each light source. Each of the plurality of powers is adjusted so as to balance the power; among the plurality of powers, the maximum power is power that intermittently lights the light source, and at least some power other than the maximum power continuously lights the light source The balance adjustment amount of the supplied power may be set based on a light amount measurement value at the maximum power among the powers other than the maximum power. In this way, it is possible to adjust the light quantity balance of a plurality of light sources with high accuracy.

Note that the present invention can be realized in various modes as described below.
(A) Image display device and control method of image display device.
(B) Projector and projector control method.

It is a schematic block diagram which shows the structure of the projector in one Embodiment. It is a schematic block diagram which shows the structure of the control part of FIG. It is explanatory drawing which shows an example of an electric current / light quantity characteristic table and a Duty / light quantity characteristic table. It is a flowchart which shows the procedure of a light source initial state confirmation process. It is a flowchart which shows the procedure of a light source change state confirmation process. It is a flowchart which shows the procedure of a light source control table production | generation process. It is a graph which shows the optical sensor value acquired in the 1st electric current-the 4th electric current. It is explanatory drawing which compares the example of a reference | standard state and a light source degradation state, and shows the electric current / light quantity characteristic table of a light source control table.

A. Embodiment:
A1. Projector configuration:
FIG. 1 is a schematic block diagram illustrating a configuration of a projector 50 according to an embodiment. The projector 50 includes a blue light illumination device 51, a yellow light illumination device 52, a dichroic mirror 25, a light guide optical system 3R, a light guide optical system 3G, a light guide optical system 3B, and a reflective liquid crystal panel. 4R, reflective liquid crystal panel 4G, reflective liquid crystal panel 4B, red light sensor 36R, green light sensor 36G, blue light sensor 36B, cross dichroic prism 5, and projection optical system 6.

  As an example, the blue light illumination device 51 emits mainly P-polarized blue light LB. As an example, the yellow light illumination device 52 emits mainly P-polarized yellow light LY.

  The dichroic mirror 25 is an optical element in which a wavelength selection film that reflects a light beam in a predetermined wavelength region and transmits a light beam in another wavelength region is formed on a substrate. In the present embodiment, as an example, the dichroic mirror 25 transmits the red light LR having a wavelength longer than a predetermined reference wavelength among the yellow light LY emitted from the yellow light illumination device 52, and determines a predetermined reference. The green light LG having a wavelength shorter than the wavelength is reflected.

  The light guide optical system 3R guides S-polarized red light reflected by the polarization beam splitter 26 out of the red light LR transmitted through the dichroic mirror 25 to the red light optical sensor 36R. On the other hand, the light guide optical system 3R guides the P-polarized red light transmitted through the polarization beam splitter 26 out of the red light LR transmitted through the dichroic mirror 25 to the reflective liquid crystal panel 4R. The light guide optical system 3 </ b> R guides S-polarized red light reflected by the polarization beam splitter 26 out of the red light reflected from the reflective liquid crystal panel 4 </ b> R to the cross dichroic prism 5.

  The light guide optical system 3G guides the S-polarized green light reflected by the polarization beam splitter 27 out of the green light LG reflected by the dichroic mirror 25 to the green light optical sensor 36G. The light guide optical system 3G guides the P-polarized green light transmitted through the polarization beam splitter 27 out of the green light LG reflected by the dichroic mirror 25 to the reflective liquid crystal panel 4G. The light guide optical system 3G guides the S-polarized green light reflected by the polarization beam splitter 27 out of the green light reflected from the reflective liquid crystal panel 4G to the cross dichroic prism 5.

  The light guide optical system 3B guides the S-polarized blue light reflected by the polarization beam splitter 28 out of the blue light LB emitted by the blue light illumination device 51 to the blue light optical sensor 36B. The light guide optical system 3B guides the P-polarized blue light transmitted through the polarization beam splitter 28 out of the blue light LB emitted by the blue light illumination device 51 to the reflective liquid crystal panel 4B. The light guide optical system 3B guides S-polarized blue light reflected by the polarization beam splitter 28 out of the blue light reflected from the reflective liquid crystal panel 4B to the cross dichroic prism 5.

  The reflective liquid crystal panel 4R modulates the red light guided by the light guide optical system 3R according to the image signal. Similarly, the reflective liquid crystal panel 4G modulates the green light guided by the light guide optical system 3G according to the image signal. Similarly, the reflective liquid crystal panel 4B modulates the blue light guided by the light guide optical system 3B according to the image signal. The cross dichroic prism 5 combines the red light guided by the light guide optical system 3R, the green light guided by the light guide optical system 3G, and the blue light guided by the light guide optical system 3B. The projection optical system 6 projects the light combined by the cross dichroic prism 5 onto a projection surface such as a screen SCR.

  The red light optical sensor 36R detects the brightness of the S-polarized red light guided by the light guide optical system 3R (in this embodiment, the light intensity is an example). The red light optical sensor 36 </ b> R outputs a red light intensity signal indicating the detected light intensity of the red light to the control unit 63. Similarly, the blue light optical sensor 36B detects the brightness of the S-polarized blue light guided by the light guide optical system 3B (in this embodiment, the light intensity is an example). The blue light optical sensor 36 </ b> B outputs a blue light intensity signal indicating the detected light intensity of the blue light to the control unit 63. Similarly, the green light optical sensor 36G detects the intensity of S-polarized green light guided by the light guide optical system 3G. The green light sensor 36G outputs a green light intensity signal indicating the intensity of the detected green light to the control unit 63.

  The blue light illumination device 51 includes a blue laser diode array 53, a collimating lens 54, a condenser lens 55, a diffusion plate 56, a pickup lens 57, a collimating lens 58, a first lens array 9, A second lens array 10, a polarization conversion element 11, and a superimposing lens 12 are provided.

  The blue laser diode array 53 is, for example, a structure in which twelve blue laser diodes 59 are arranged in an array of 4 × 3. The same number of collimating lenses 54 as the individual blue laser diodes 59 are provided at positions corresponding to the individual blue laser diodes 59. The first lens array 9 has a plurality of first small lenses 13 for dividing the illumination light beam emitted from the collimating lens 58 into a plurality of partial light beams. The second lens array 10 has a plurality of second small lenses 14 corresponding to the plurality of first small lenses 13 of the first lens array 9. The polarization conversion element 11 converts each partial light beam from the second lens array 10 into approximately one type of linearly polarized light having a uniform polarization direction and emits the converted light. The superimposing lens 12 superimposes each partial light beam emitted from the polarization conversion element 11 in the illuminated area.

  The blue light LB emitted from the blue laser diode 59 is collimated by the collimating lens 54, then condensed by the condensing lens 55, and irradiated on the diffusion plate 56, thereby forming a point light source. Blue diffused light from each point light source on the diffusion plate 56 passes through the pickup lens 57 and is collimated by the collimating lens 58 and then enters the first lens array 9.

  The first lens array 9 has a function as a light beam splitting optical element that splits the parallel light from the parallelizing lens 58 into a plurality of partial light beams. The first lens array 9 has a configuration in which a plurality of first small lenses 13 are arranged in a matrix of a plurality of rows and a plurality of columns in a plane orthogonal to the illumination optical axis 51ax. Although not illustrated, the outer shape of the first small lens 13 is similar to the outer shape of the image forming region that emits image light of the reflective liquid crystal panel 4B.

  The second lens array 10, together with the superimposing lens 12, has a function of forming an image of each first small lens 13 of the first lens array 9 in the vicinity of the image forming area of the reflective liquid crystal panel 4B. Similar to the first lens array 9, the second lens array 10 has a configuration in which a plurality of second small lenses 14 are arranged in a matrix of a plurality of rows and a plurality of columns in a plane orthogonal to the illumination optical axis 51ax.

  The polarization conversion element 11 emits the polarization direction of each partial light beam divided by the first lens array 9 as approximately one type of linearly polarized light having the same polarization direction. Of the illumination light from the blue laser diode 59, the polarization conversion element 11 transmits one polarized light (for example, P-polarized light) and reflects the other polarized light (for example, S-polarized light) in a direction perpendicular to the illumination optical axis 51ax. A polarization separation layer that reflects the light having the other polarization component reflected by the polarization separation layer in a direction parallel to the illumination optical axis 51ax, and a light having one polarization component reflected by the polarization separation layer. And a retardation plate that converts light into light having the other polarization component. In addition, although the light which permeate | transmitted the polarization conversion element 11 turns into P polarization substantially, not all become P polarization, and S polarization is mixed.

  The superimposing lens 12 is an optical element for condensing a plurality of partial light beams that have passed through the first lens array 9, the second lens array 10, and the polarization conversion element 11 and superimposing them on the vicinity of the image forming area of the reflective liquid crystal panel 4B. is there. The superimposing lens 12 is disposed so that the optical axis of the superimposing lens 12 and the illumination optical axis 51ax of the blue light illumination device 51 substantially coincide. The superimposing lens 12 may be composed of a compound lens in which a plurality of lenses are combined.

  The yellow light illumination device 52 includes an excitation laser diode array 60, a collimating lens 54, a condensing lens 55, a phosphor substrate 61, a pickup lens 57, a collimating lens 58, and a first lens array 9. And a second lens array 10, a polarization conversion element 11, and a superimposing lens 12. For example, the excitation laser diode array 60 includes 30 excitation laser diodes 62 arranged in an array of 6 × 5. The excitation laser diode 62 emits ultraviolet light or blue light as excitation light for exciting the phosphor. The collimating lens 54 is provided corresponding to each excitation laser diode 62. The phosphor substrate 61 is a substrate in which a phosphor layer that emits yellow light upon receiving excitation light such as ultraviolet light or blue light is formed on the substrate.

  Each excitation light emitted from the excitation laser diode 62 is collimated by the collimating lens 54, then condensed by the condensing lens 55, and irradiated onto the phosphor substrate 61 to form a point light source. The The yellow light LY emitted from each point light source on the phosphor substrate 61 passes through the pickup lens 57 and is collimated by the collimating lens 58 and then enters the first lens array 9.

  The first lens array 9, the second lens array 10, the polarization conversion element 11, and the superimposing lens 12 in the yellow light illumination device 52 are respectively the first lens array 9 and the second lens array 10 in the blue light illumination device 51. Since the configuration is the same as that of the polarization conversion element 11 and the superimposing lens 12, the description thereof is omitted. However, the yellow light illumination device 52 is different in that the illumination optical axis 51ax of the blue light illumination device 51 is changed to the illumination optical axis 52ax.

  The light guide optical system 3B includes a condenser lens 32B, a first diaphragm (incident angle limiting member) 37, a polarization beam splitter (polarization separation element) 28, a second diaphragm 38, and a polarizing plate 34B. .

  The condensing lens 32B converts each partial light beam of the blue light LB collected by the superimposing lens 12 into a light beam substantially parallel to each principal ray. The first stop 37 stops the substantially parallel light beam converted by the condenser lens 32B. As a result, the blue light LB collected by the superimposing lens 12 enters the polarization beam splitter 28 via the condensing lens 32B and the first diaphragm 37. At this time, the illumination light beam from the blue light illumination device 51 is aligned by the polarization conversion element 11 to approximately one type of linearly polarized light (for example, P-polarized light) whose polarization direction is substantially aligned. The passed light passes through the polarization beam splitter 28 and is incident on the blue reflective liquid crystal panel 4B. The other condenser lens 32R and condenser lens 32G are configured in the same manner as the condenser lens 32B.

  The polarization beam splitter 28 is a plate-type polarization beam splitter, and has a configuration in which a polarization separation film is provided on a translucent substrate. The polarization beam splitter 28 has a function of transmitting one polarized light and reflecting the other polarized light. In the present embodiment, the polarization beam splitter 28 has a function of transmitting P-polarized light and reflecting S-polarized light as an example. The second stop 38 stops the S-polarized blue light beam reflected by the polarization beam splitter 28. Thereby, the light narrowed down by the second diaphragm 38 is guided to the blue light optical sensor 36B.

  The polarization beam splitter 28 reflects S-polarized blue light out of the blue light reflected from the reflective liquid crystal panel 4B and transmits P-polarized blue light. Thereby, the S-polarized blue light reflected by the polarization beam splitter 28 is guided to the polarizing plate 34B. The polarizing plate 34B allows only the light polarized in a predetermined direction out of the guided blue light. Thereby, blue light polarized in a predetermined direction is guided to the cross dichroic prism 5. The other polarization beam splitter (polarization separation element) 26 and polarization beam splitter (polarization separation element) 27 are also configured in the same manner as the polarization beam splitter 28 described above.

  As described above, the illumination light beam from the illuminating device 51 for blue light is substantially aligned with the P-polarized light by the polarization conversion element 11, and the blue P-polarized light is transmitted through the polarization beam splitter 28 and is reflected liquid crystal for blue light. Incident on panel 4B. However, in reality, not all the light transmitted through the polarization conversion element 11 is converted to P-polarized light, but S-polarized light is also mixed. Therefore, the S-polarized light incident on the polarization beam splitter 28 is reflected by the polarization beam splitter 28. A blue light optical sensor 36B is provided on the S-polarized light path reflected by the polarization beam splitter 28 in the blue light path.

  The light guide optical system 3R includes a condenser lens 32R, a first diaphragm 37, a polarization beam splitter (polarization separation element) 26, a second diaphragm (incident angle limiting member) 38, and a polarizing plate 34R. .

  The condenser lens 32R converts each partial light beam of the red light LR that has passed through the dichroic mirror 25 into a light beam that is substantially parallel to each principal ray. The first stop 37 stops the substantially parallel light beam converted by the condenser lens 32R. As a result, the red light LR that has passed through the dichroic mirror 25 enters the polarization beam splitter 26 via the condenser lens 32R and the first diaphragm 37. At this time, since the illumination light beam from the yellow light illumination device 52 is aligned with approximately one type of linearly polarized light (for example, P-polarized light) whose polarization directions are substantially aligned by the polarization conversion element 11, the condenser lens 32 </ b> R is provided. The passed light passes through the polarization beam splitter 26 and is incident on the reflective liquid crystal panel 4R for red light.

  The polarization beam splitter 26 has a function of transmitting P-polarized light and reflecting S-polarized light as an example. The second stop 38 stops the light beam of S-polarized color light reflected by the polarization beam splitter 26. Thereby, the light narrowed down by the second diaphragm 38 is guided to the red light optical sensor 36R.

  The polarization beam splitter 26 reflects S-polarized red light out of the red light reflected from the reflective liquid crystal panel 4R and transmits P-polarized red light. Accordingly, the P-polarized red light reflected by the polarization beam splitter 26 is guided to the polarizing plate 34R. The polarizing plate 34R allows only the light polarized in a predetermined direction out of the guided red light. Thereby, red light polarized in a predetermined direction is guided to the cross dichroic prism 5.

  The light guide optical system 3G includes a condenser lens 32G, a first diaphragm 37, a polarization beam splitter (polarization separation element) 27, a second diaphragm (incident angle limiting member) 38, and a polarizing plate 34G. .

  The condensing lens 32G converts each partial light beam of the green light LG reflected by the dichroic mirror 25 into a light beam substantially parallel to each principal ray. The first stop 37 stops the substantially parallel light flux converted by the condenser lens 32G. As a result, the green light LG reflected by the dichroic mirror 25 enters the polarization beam splitter 27 via the condenser lens 32G and the first diaphragm 37. At this time, the illumination light beam from the yellow light illumination device 52 is aligned with approximately one type of linearly polarized light (for example, P-polarized light) having substantially the same polarization direction by the polarization conversion element 11, so The passed light passes through the polarization beam splitter 27 and is incident on the green reflective liquid crystal panel 4G.

  For example, the polarization beam splitter 27 transmits P-polarized light and reflects S-polarized light. The second stop 38 stops the S-polarized green light beam reflected by the polarization beam splitter 27. Thereby, the light narrowed down by the second diaphragm 38 is guided to the green light optical sensor 36G.

  The polarization beam splitter 27 reflects S-polarized green light out of the green light reflected from the reflective liquid crystal panel 4G and transmits P-polarized green light. Thereby, the S-polarized green light reflected by the polarization beam splitter 27 is guided to the polarizing plate 34G. The polarizing plate 34G allows only the light polarized in a predetermined direction out of the guided green light. Thereby, green light polarized in a predetermined direction is guided to the cross dichroic prism 5.

  The reflective liquid crystal panel 4R, the reflective liquid crystal panel 4G, and the reflective liquid crystal panel 4B are light modulators that modulate illumination light according to an image signal and emit image light representing an image. The reflective liquid crystal panel 4 </ b> R and the reflective liquid crystal panel 4 </ b> G are light modulation units to be illuminated by the yellow light illumination device 52. The reflective liquid crystal panel 4 </ b> B is a light modulation unit to be illuminated by the blue light illumination device 51. The reflective liquid crystal panel 4R, the reflective liquid crystal panel 4G, and the reflective liquid crystal panel 4B correspond to the “image light emitting unit” of the present invention.

  The reflective liquid crystal panel 4R, the reflective liquid crystal panel 4G, and the reflective liquid crystal panel 4B include a pair of substrates that sandwich the liquid crystal layer and a reflective layer (or reflective electrode) that is disposed on the substrate side facing the light incident side substrate. ) And. Further, as shown in FIG. 1, on the surface opposite to the light incident side of the reflective liquid crystal panel 4R, the reflective liquid crystal panel 4G, and the reflective liquid crystal panel 4B, the radiation fins 33R, the radiation fins 33G, and the radiation fins 33B, respectively. Is arranged.

  The cross dichroic prism 5 is an optical element that combines image light modulated for each color light emitted from the polarizing plate 34R, the polarizing plate 34G, and the polarizing plate 34B to form image light representing a color image. The cross dichroic prism 5 has a substantially square shape in plan view in which four right angle prisms are bonded together, and a dielectric multilayer film is formed on the substantially X-shaped interface in which the right angle prisms are bonded together. The dielectric multilayer film formed at one of the substantially X-shaped interfaces reflects the blue light LB, and the dielectric multilayer film formed at the other interface reflects the red light LR. By these dielectric multilayer films, the blue light LB and the red light LR are bent and aligned with the traveling direction of the green light LG that passes through the cross dichroic prism 5, thereby synthesizing image light of three colors. The color image formed by the image light emitted from the cross dichroic prism 5 is enlarged and projected by the projection optical system 6 to form an image on the screen SCR.

  The blue laser diode array 53 is provided with a BLD temperature sensor 53T for grasping the temperature state of each blue laser diode 59 as a whole. Similarly, the excitation laser diode array 60 is provided with an excitation LD temperature sensor 60T for grasping the temperature state of each excitation laser diode 62 as a whole.

  In addition, the heat radiation fin 33B of the reflective liquid crystal panel 4B for blue light has a temperature for the B light panel in order to grasp the temperature state of the optical member arrangement region including the light guide optical system 3B and the reflective liquid crystal panel 4B. A sensor 33BT is provided. Similarly, the radiation fin 33R of the reflective liquid crystal panel 4R for red light has an R light panel temperature in order to grasp the temperature state of the optical member arrangement region including the light guide optical system 3R and the reflective liquid crystal panel 4R. A sensor 33RT is provided. A thermistor is applied as the temperature sensor. However, the temperature sensor is not limited to the thermistor, and various general temperature sensors can be used.

  The control unit 63 controls the adjustment of the light amount of the excitation laser diode 62 according to the intensity of the red light detected by the red light sensor 36R, and adjusts the intensity of the blue light detected by the blue light sensor 36B. Accordingly, the adjustment of the light quantity of the blue laser diode 59 is controlled. Further, the control unit 63 controls the reflectance of each pixel of the reflective liquid crystal panels 4R, 4G, and 4B according to a video signal (not shown). The video signal input to the control unit 63 may be a plurality of image signals indicating images of successive frames or an image signal indicating an image of one frame.

  FIG. 2 is a schematic block diagram showing the configuration of the control unit 63 of FIG. In the drawing, in addition to the control unit 63 and the reflective liquid crystal panels 4R, 4G, and 4B, a light source 71 including a blue laser diode 59 and an excitation laser diode 62 is shown, and a red light photosensor 36R, not shown. The light detection part 72 provided with the light sensor 36G for green light and the light sensor 36B for blue light is shown. Furthermore, a light source temperature detection unit 73 including a BLD temperature sensor 53T and an excitation LD temperature sensor 60T is shown, and a panel temperature detection unit 74 including a B light panel temperature sensor 33BT and an R light panel temperature sensor 33RT is illustrated. ing.

  The control unit 63 includes an image processing unit 64 and liquid crystal drive units 66R, 66G, and 66B as image control units, and a drive control unit 65A and a storage unit 65B as light source control units that control the output of the light source 71. , A PWM signal generation unit 67, an excitation laser diode drive unit 68, and a blue laser diode drive unit 69. The output of the light source 71 is, for example, brightness. The brightness corresponds to, for example, light intensity (light quantity).

  The image processing unit 64 applies various image quality correction processes to the received video signal, and outputs the signals after the image quality correction process to the liquid crystal drive units 66R, 66G, and 66B. Accordingly, the liquid crystal driving units 66R, 66G, and 66B control the reflectances of the reflective liquid crystal panels 4R, 4G, and 4B, respectively, using the signals input from the image processing unit 64.

  The drive control unit 65A performs processing and control for dimming control of the light source 71 in accordance with the received control signal. Here, the control signal is a signal including information relating to user settings input by the user or display of the color mode on a menu screen (not shown) displayed on the screen SCR (FIG. 1). Thereby, the light quantity of the light source 71 is controlled based on the user setting or the brightness and color setting linked with the color mode. The drive control unit 65A may perform dimming control adapted to the brightness (gradation value) of the received video signal.

  The drive control unit 65A executes a control program (not shown) stored in the storage unit 65B, whereby a drive processing unit 65a, a current / light quantity characteristic deriving unit 65b, a light source confirmation unit 65c, a light quantity measurement unit 65d, and It is a computer that functions as the temperature measuring unit 65e. The storage unit 65B stores a current / light quantity characteristic table (current / light quantity characteristic LUT) 65f and a duty / light quantity characteristic table (Duty / light quantity characteristic LUT) 65g. The current / light quantity characteristic table 65f and the duty / light quantity characteristic table 65g are derived by the current / light quantity characteristic deriving unit 65b according to the user setting included in the control signal and stored in the storage unit 65B.

  FIG. 3 is an explanatory diagram showing an example of a current / light quantity characteristic table and a duty / light quantity characteristic table. The current / light quantity characteristic table and the duty / light quantity characteristic table are not shown as specific examples of the excitation laser diode 62 or the blue laser diode 59 included in the light source 71 but are schematically shown by way of an example of a laser diode as a light source. ing.

  The current / light quantity characteristic table in FIG. 3A shows the relationship between the drive current and the brightness (corresponding to the light quantity) when the laser diode is driven with a constant current. The brightness is indicated by the relative brightness [%] with respect to the brightness L100 at the current I100 set as the maximum current in the use range in the constant current drivable range. The current Ism is a current value set as a lower limit current at which light emission is possible even if the light emission threshold current of the laser diode changes according to deterioration with time or usage environment. Further, the current Ism is more preferably in the range of 35% to 65% of the current I100 set as the maximum current in the use range in the constant current drivable range. In this way, it is possible to maintain a wide dimming range until the end of the life of the laser diode as the light source.

  This current / light quantity characteristic table is a current that increases as the brightness increases in a brightness area of brightness Lsm or higher, and is related to brightness in a brightness area lower than brightness Lsm. The current values are the same (current Ism). According to this current / light quantity characteristic table, in a brightness area of brightness Lsm or higher, for example, a drive current corresponding to brightness Ltg1 (also referred to as “supply current”) changes according to changes in brightness. The current Itg1 can be derived. Further, in the brightness region lower than the brightness Lsm, for example, as the drive current corresponding to the brightness Ltg2, the same current Itg2 as the current Ism corresponding to the brightness Lsm is derived regardless of the magnitude of the brightness Ltg2. can do.

  The duty / light quantity characteristic table in FIG. 3B shows the relationship between the brightness (corresponding to the light quantity) and the duty (duty) of the PWM signal when the laser diode is driven by PWM. In this duty / light quantity characteristic table, the duty of the PWM signal is 100% because the laser diode can be driven with a constant current according to the current / light quantity characteristic table in the brightness region of brightness Lsm or higher. On the other hand, in the brightness region lower than the brightness Lsm, the duty of the PWM signal changes from 0 to 100% according to the change from 0% to Lsm [%] of the brightness. . According to this duty / light quantity characteristic table, for example, in the area of brightness equal to or higher than brightness Lsm, the duty Dlsm corresponding to the brightness Lsm is used as the duty corresponding to the brightness Ltg1, regardless of the magnitude of the brightness Ltg1. The same duty Dtg1 as (100%) can be derived. In a region lower than the brightness Lsm, for example, a duty Dtg2 that changes according to a change in brightness can be derived as a duty corresponding to the brightness Ltg2.

  The actual current / light quantity characteristic table 65f and duty / light quantity characteristic table 65g include the current / light quantity characteristic table and duty / light quantity characteristic table for the blue laser diode 59, and the current / light quantity characteristic for the excitation laser diode 62. The table and the duty / light quantity characteristic table are derived by the current / light quantity characteristic deriving unit 65b as described later and stored in the storage unit 65B.

  The drive processing unit 65a refers to the current / light quantity characteristic table 65f and the duty / light quantity characteristic table 65g to perform excitation drive current value CY and PWM drive of the excitation laser diode 62 corresponding to the brightness setting value. An excitation duty value DutyY is derived. Similarly, the drive processing unit 65a derives a blue drive current value CB for the blue laser diode 59 and a blue duty value DutyB for PWM drive.

  The PWM signal generation unit 67 generates a PWMY signal corresponding to the blinking of the excitation laser diode 62 from the excitation duty value DutyY. The PWM signal generation unit 67 outputs the generated PWMY signal to the excitation laser diode drive unit 68. Similarly, the PWM signal generation unit 67 generates a PWMB signal corresponding to the blinking of the blue laser diode 59 from the blue duty value DutyB. The PWM signal generation unit 67 outputs the generated PWMB signal to the blue laser diode driving unit 69.

  The excitation laser diode drive unit 68 performs ON / OFF control of the excitation laser diode 62 based on the waveform of the PWMY signal. When the excitation duty value DutyY is 100%, the excitation laser diode drive unit 68 performs constant current driving with the excitation drive current value CY without performing the ON / OFF control of the excitation laser 62. The blue laser diode driving unit 69 performs ON / OFF control of the blue laser diode 59 based on the waveform of the PWMB signal. When the blue duty value DutyB is 100%, the blue laser diode driving unit 69 performs constant current driving with the blue driving current value CB without performing ON / OFF control of the blue laser diode 59.

  As can be seen from the above description, the drive control unit 65A, more specifically, the drive processing unit 65a, the storage unit 65B, the PWM signal generation unit 67, the excitation laser diode drive unit 68, and the blue laser diode drive unit. 69 corresponds to the light source controller of the present invention.

  As will be described later, the light source confirmation unit 65c confirms the initial state of the light source at the time of shipment inspection or initial inspection when the light source 71 is replaced as a reference state (hereinafter also referred to as “light source initial state confirmation processing”). Then, the change state of the light source due to a change with time, an environmental change or the like is confirmed (hereinafter also referred to as “light source change state confirmation process”). The light source change state confirmation process is performed when a predetermined time, for example, an accumulated use time or a simple set time has elapsed, during an operation end sequence of the apparatus or when a confirmation instruction is issued by the user. Executed.

  When the light source confirmation unit 65c executes the light source initial state confirmation process or the light source change state confirmation process, the light quantity measurement unit 65d and the temperature measurement unit 64e operate as follows. That is, the light amount measuring unit 65d measures the amount of light based on the light intensity of the red light detected by the red light optical sensor 36R of the light detecting unit 72, and also detects the light of the blue light detected by the blue light optical sensor 36B. Measure the light intensity based on intensity. The temperature measuring unit 65e measures the temperature of the excitation laser diode 62 detected by the excitation LD temperature sensor 60T of the light source temperature detection unit 73 and the temperature of the blue laser diode 59 detected by the BLD temperature sensor 53T. Measure. The temperature measurement unit 65e is detected by the R light panel temperature sensor 33RT of the panel temperature detection unit 74 as the temperature of the optical member arrangement region including the light guide optical system 3R for red light and the reflective liquid crystal panel 4R. The temperature of the reflective liquid crystal panel 4R for red light is measured. The temperature measuring unit 65e is detected by the B light panel temperature sensor 33BT of the panel temperature detecting unit 74 as the temperature of the optical member arrangement region including the blue light guiding optical system 3B and the reflective liquid crystal panel 4B. The temperature of the reflective liquid crystal panel 4B for blue light is measured.

A2. Light source status check:
(1) Light Source Initial State Confirmation FIG. 4 is a flowchart showing a procedure of light source initial state confirmation processing. As described above, this process is executed by the light source confirmation unit 65c, for example, by operating an execution start button (not shown) at the time of shipping inspection or when the light source 71 is replaced.

  When the light source initial check process is started, first, a factor that affects the amount of light received by the light detection unit 72 is set to a predetermined state. Specifically, in step S102, all of the reflective liquid crystal panels 4R, 4G, and 4B are set to a black display state, and in step S104, the optical diaphragm disposed in the optical system from the illumination devices 51 and 52 to the cross dichroic prism 5 is set. 37, 38 and the optical filter are set to a fully open state.

  And the temperature of the reflective liquid crystal panel 4R for red light, the reflective liquid crystal panel 4B for blue light, the excitation laser diode 62, and the blue laser diode 59 is measured by the temperature measuring unit 65e. Thereby, in step S106, the temperature sensor reference value RPAr of the R light panel temperature sensor 33RT, the temperature sensor reference value BPAr of the B light panel temperature sensor 33BT, the temperature sensor reference value YLSr of the excitation LD temperature sensor 60T, and The temperature sensor reference value BLSr of the BLD temperature sensor 53T is acquired. The acquired temperature sensor reference values RPAr, BPAr, YLSr, and BLSr are stored in the nonvolatile storage area of the storage unit 65B. The light emitted from the excitation laser diode 62 is converted into yellow light (Y light). Hereinafter, the excitation laser diode 62 is also referred to as a Y light source. Further, since the blue laser diode 59 emits blue light (B light), it is also referred to as a B light source below.

  Next, in steps S108 to S114, the first current I1 to the fourth current I4, which are a part of the entire range predetermined as the drive current (supply current) by the drive processing unit 65a, are sequentially set and excited. The laser diode 62 and the blue laser diode 59 are driven. In each step, the light intensity detected by the red light sensor 36R and the light intensity detected by the blue light sensor 36B are measured as light amounts, and the light of the red light sensor 36R in each current setting condition is measured. The sensor reference values RSEr1 to RSEr4 and the optical sensor reference values BSEr1 to BSEr4 of the blue light optical sensor 36B are acquired. The obtained optical sensor reference values RSEr1 and BSEr1 at the first current I1, the optical sensor reference values RSEr2 and BSEr2 at the second current I2, the optical sensor reference values RSEr3 and BSEr3 at the third current I3, and the optical sensor at the fourth current I4. The reference values RSEr4 and BSEr4 are stored in the nonvolatile storage area of the storage unit 65B. After the process of step S114 ends, the light source initial state confirmation process ends.

  The first current I1 is the maximum current value used when the light source is intermittently turned on, such as in moving image response characteristics improvement in 3D display or 2D display, and the second current I2 to the fourth current I4 are It is a current value in the case of continuous lighting in normal 2D display. Further, the first current I1 is set to the maximum current value, and the fourth current I4 is set to the lowest current Ism that can ensure light emission in consideration of the variation of the light emission lower limit threshold value of the light source. In the present embodiment, the first current I1 to the fourth current I4 as drive currents of the excitation laser diode 62 are I1 = 2.7A, I2 = 2.3A, I3 = 1.5A, and I4 = 0.9A. Is set. Further, the first to fourth currents I1 to I4 as drive currents of the blue laser diode 59 are set to I1 = 1.5A, I2 = 1.2A, I3 = 0.9A, and I4 = 0.6A. Yes.

  In addition, it is preferable that the current values of the first current I1 to the fourth current I4 are spaced at least 0.3 A or more in order to ensure both high measurement accuracy and short measurement time. In each of steps S108 to S114, after setting the drive current and driving the light source, the interval until the photosensor value is acquired is set to a time setting that takes into account the response characteristics of the photosensor (for example, about 1 second). It is preferable. However, with this time setting, the amount of light that changes depending on the temperature characteristics of an optical member such as a light source, an optical sensor, a light guide optical system, or a liquid crystal panel cannot be reflected in the optical sensor value. The amount of light that changes due to such temperature characteristics can be dealt with by applying a correction coefficient described later.

  The first current I1 is the maximum current value that can be set under intermittent lighting conditions as described above. The first current I1 is a current value that is not used in continuous lighting. Therefore, in the acquisition of the optical sensor reference value in step S109, the light quantity is measured under intermittent lighting conditions, and the measured light quantity measurement value is multiplied by a correction coefficient to be converted into a light quantity assumed during continuous lighting. The correction coefficient is set by experimentally obtaining in advance a coefficient value for correcting the difference between intermittent lighting and continuous lighting. Thereby, it is possible to omit the measurement by setting the current value for continuous lighting and the current value for intermittent lighting separately, so that the measurement time can be shortened. Moreover, the same setting is possible for both continuous lighting and intermittent lighting.

  The optical sensor reference values RSEri (i corresponding to the first current I1 to the fourth current I4) in the temperature sensor reference values RPAr, BPAr, YLSr, BLSr, the first current I1 to the fourth current I4 obtained as described above. BSEri is used to generate a current / light quantity specifying table and a duty / light quantity characteristic table (see FIG. 3) as a light source control table in the current / light quantity characteristic deriving unit 65b, as will be described later. Used.

(2) Confirmation of Light Source Change State FIG. 5 is a flowchart showing a procedure of light source change state confirmation processing. As described above, this process is executed during the operation end sequence of the apparatus, during the apparatus start-up sequence, or when the user instructs execution of the confirmation process when the accumulated use time or the simple set time has elapsed.

  When the light source change state confirmation process is started, all of the reflective liquid crystal panels 4R, 4G, and 4B are set to a black display state in step S202, similarly to steps S102 and S104 (FIG. 4) of the light source initial state confirmation process. In step S204, the optical diaphragms 37 and 38 and the optical filter are set to a fully opened state.

  Next, in step S206, similarly to step S106 of the light source initial state confirmation process, the temperature sensor value RPA of the R light panel temperature sensor 33RT, the temperature sensor value BPA of the B light panel temperature sensor 33BT, and the excitation LD temperature The temperature sensor value YLS of the sensor 60T and the temperature sensor value BLS of the BLD temperature sensor 53T are acquired. The acquired temperature sensor values RPA, BPA, YLS, and BLS are stored in the nonvolatile storage area of the storage unit 65B.

  In steps S208 to S214, as in steps S108 to S114 of the light source initial state confirmation process, the optical sensor value RSEi (i corresponds to the first current I1 to the fourth current I4) in the first current I1 to the fourth current I4. BSEi is acquired. The acquired optical sensor values RSEi and BSEi are stored in the nonvolatile storage area of the storage unit 65B.

Next, in step S216, the temperature correction coefficient αty of the Y light source and the temperature correction coefficient αtb of the B light source are derived from the following equations (1) and (2). Here, the Y light source means each excitation laser diode 62, and the B light source means each blue laser diode 59.
αty = 1 + (Yα * (YLS−YLSr) + Yβ * (RPA−RPAr)) (1)
αtb = 1 + (Bα * (BLS−BLSr) + Bβ * (BPA−BPAr)) (2)
However, Yα, Yβ, Bα, Bβ are coefficients determined in advance by experiments.

In step S218, as shown in the following expressions (3) and (4), the acquired optical sensor value RSEi (i is a value of 1 to 4 corresponding to the first current I1 to the fourth current I4), The corrected optical sensor values CRSEi and CBSEi are derived by multiplying BSEi by temperature correction coefficients αty and αtb.
CRSEi = RSEi * αty (3)
CBSEi = BSEi * αtb (4)
As a result, it is possible to improve the occurrence of errors in measurement of changes caused by deterioration of the light source due to the amount of light received by the optical sensor changing depending on the light source temperature and the optical member temperature at the time of obtaining the optical sensor value. it can.

Next, in step S220, in order to keep the balance of R light, G light, and B light (referred to as “white balance”), that is, the balance between the Y light source and the B light source, the following expression (5) is given. The balance control value LSB_Y of the Y light source or the balance control value LSB_B of the B light source shown in the following equation (6) is derived. The derived balance control values LSB_Y and LSB_B are stored in the nonvolatile storage area of the storage unit 65B.
LSB_Y = LSB_Y (T) * [(RSEr / BSEr) / (RSE / BSE)] (5)
LSB_B = LSB_B (T) * [(RSE / BSE) / (RSEr / BSEr)] (6)
However, LSB_Y (T) and LSB_B (T) are currently set balance control values.

  For example, when (RSEr / BSEr)> (RSE / BSE), it is considered that the Y light is weaker than the reference state or the B light is stronger. Here, when the light source is in a deteriorated state, the control for increasing the amount of light has a high risk of deteriorating the reliability of the apparatus due to an increase in heat loss, etc. Therefore, it is desirable to perform the control for decreasing the amount of light. Therefore, in order to maintain the Y light as it is, the Y light source is controlled with the balance control value LSB_Y (T) as it is, and the B light source is controlled so as to weaken the B light with the balance control value LSB_B obtained by the above equation (6). Do. On the other hand, in the case of (RSEr / BSEr) <(RSE / BSE), the B light source is controlled with the balance control value LSB_B (T) as it is in order to maintain the B light as it is, and obtained by the above equation (5). The Y light source is controlled so as to weaken the Y light by the balance control separation LSB_Y. This control is executed by deriving the drive current in the drive processing unit 65a using the brightness set value multiplied by the balance control value as the brightness set value.

  RSEr, BSEr, RSE, and BSE used in the above formulas (5) and (6) are optical sensor reference values RSEri (i is the first current I1 to the fourth current) measured by the first current I1 to the fourth current I4. Measured at the second current I2 which is the maximum current used in constant current driving in the normal display (2D display) among the BSEri and the optical sensor values RSEi and BSEi. It is preferable to use the optical sensor reference values RSEr2 and BSEr2 and the optical sensor values RES2 and BSE2. In this way, the balance accuracy can be increased. However, the present invention is not limited to this, and an average value of measured values of the first current I1 to the third current I3 and an average value of measured values of the first current I1 to the fourth current I4 may be used.

  After the process of step S220 ends, the light source change state confirmation process ends. When this light source change state confirmation process is executed during the end sequence of the apparatus, control based on the optical sensor value and the balance control value acquired from the next startup is executed.

  Further, the optical sensor values RSEi (i corresponding to the first current I1 to the fourth current I4) in the temperature sensor values RPA, BPA, YLS, BLS, the first current I1 to the fourth current I4 obtained as described above. BSEi is a temperature sensor reference value RPA, BPA, YLS, BLS, and the optical sensor reference values RSEri and BSEri in the first current I1 to the fourth current I4, as described later. The light quantity characteristic deriving unit 65b is used to generate a current / light quantity specifying table and a duty / light quantity characteristic table (see FIG. 3) as a light source control table.

A3. Light source control table generation:
FIG. 6 is a flowchart showing the procedure of the light source control table generation process. This process is executed by the current / light quantity characteristic deriving unit 65b every time the apparatus is started or when the setting state is changed, for example, when a display mode such as 2D mode, 3D mode, cinema mode, graphic mode is changed. The

  In step S302, similarly to step S216 of the light source change state confirmation process, temperature correction coefficients αty and αtb are derived from equations (1) and (2). In step S304, current correction coefficients αdy and αdb are derived. The current correction coefficient is a coefficient for correcting a difference between an optical sensor value read when the driving current of the light source is continuously changed and an optical sensor value read in a stable state. The current correction coefficients αdy and αdb are determined in advance by experiments, stored in the nonvolatile storage area of the storage unit 65B, and derived by reading from the storage unit 65B.

Next, in step S306, as shown in the following expressions (7) and (8), the optical sensor value RSEi (i is a value of 1 to 4 corresponding to the first current I1 to the fourth current I4), BSEi Is multiplied by the temperature correction coefficients αty and αtb and the current correction coefficients αdy and αdb to derive corrected optical sensor values PRSEi and PBSEi.
PRSEi = RSEi * αty * αdy (7)
PBSEi = BSEi * αtb * αdb (8)

  In step S308, as described below, a light source control table is generated using the derived corrected optical sensor values PRSEi and PBSEi.

  FIG. 7 is a graph showing optical sensor values acquired in the first current I1 to the fourth current I4. This graph is not a specific example but schematically shows a light source as an example. The photosensor value is shown as a relative value with the photosensor reference value Lr2 at the second current I2 as a reference (100%).

  With respect to the optical sensor values Lr1 to Lr4 (indicated by solid and dotted circles) in the reference state, the optical sensor value depends on the temperature and the response characteristics of the optical sensor, for example, Lt1 to Lt4 (indicated by solid lines and dotted lines) To change. This difference can be set to the same state as the reference value by using the corrected sensor value corrected by the temperature correction coefficient and the current correction coefficient.

  In a state where the light source is deteriorated, the optical sensor value is in a lowered state as indicated by L1 to L4 (indicated by a solid line and a dotted line Δ). In this case, when the light source is controlled by obtaining the current corresponding to the set brightness using the light source control table in the reference state, the set brightness is greatly different. Therefore, as described above, it is required to generate the light source control table using the corrected sensor value obtained by correcting the light sensor value acquired in the light source change state confirmation process with the temperature correction coefficient and the current coefficient.

  FIG. 8 is an explanatory diagram showing a current / light quantity characteristic table in the light source control table in comparison with an example of a reference state and a light source deterioration state. This current / light quantity characteristic table is not a specific example, but a current / light quantity characteristic in the case of corresponding to intermittent lighting such as 3D display using photosensor values acquired with four current values taking a certain light source as an example. The table is shown schematically. Further, the photosensor value is shown as a relative value with the photosensor value at the second current I2 as the brightness reference (100%).

  In the reference state, the current / light quantity characteristic table indicated by the solid line is derived by performing interpolation calculation (for example, linear interpolation calculation) between the optical sensor reference values Lr1 to Lr4 in the first current I1 to the first current I4. Can do. Similarly, in the light source deterioration state, the current / characteristic table indicated by the alternate long and short dash line can be derived by performing interpolation calculation between the corrected optical sensor values L1 to L4 in the first current I1 to the first current I4. it can.

  FIG. 8 shows the photosensor value at the second current I2 as the brightness reference (100%), but the photosensor value at the first current I1 may be shown as a relative value with the brightness reference. Good. Further, FIG. 8 shows a case where intermittent lighting such as 3D display is supported, but in the case of only continuous lighting such as 2D display, three optical sensor values of the second current I2 to the fourth current I4 are set. The current / light quantity characteristic table may be generated by using them.

  A duty / light quantity characteristic table for realizing a brightness darker than the brightness Lrsm (reference state Lr4) and Lsm (degraded state L4) corresponding to the fourth current I4, that is, the minimum current Ism is shown in FIG. As shown, the brightness Lrsm and Lsm at 0% to the lowest current Ism are generated so that the duty varies linearly at 0% to 100%.

  As described above, in the present embodiment, the optical sensor value corresponding to the light amount measured in each of a plurality of drive currents (supply currents) corresponding to the brightness of the usage range is actually measured. By correcting based on the correction coefficient (temperature correction coefficient and current correction coefficient) according to the use conditions, a highly accurate light source control table can be generated in a short measurement time. Then, by using the generated light source control table, it is possible to control the light source with high accuracy according to the set brightness. Note that the set brightness is, for example, when the adaptive dimming according to the video is performed with the high brightness setting, the brightness of the adaptive dimming (for example, 100%) is set to the brightness setting for the high brightness setting (for example, 100%). 70%) and further multiplied by the light source balance control value described above.

  The light source control table can control the light amounts of the Y light source and the B light source while maintaining a good white balance (also called “color balance”) by giving an accuracy of about 12 bits. In this case, the number of controllable current settings is about 1000. However, as described above, high-precision control corresponding to 12-bit precision is possible only by measuring the amount of light with the optical sensor at a small number of current settings. is there.

B. Variation:
(1) Modification 1
The optical configuration of the above embodiment is not limited to the optical configuration of FIG. For example, the phosphor substrate 61 may be of a reflective type, and a fine optical configuration such as the presence or absence of a diffusion plate is merely a design matter, and is not limited to these. Moreover, the structure which used three LED of red (R) green (G) blue (B) as a light source may be sufficient. Further, one laser diode or one LED may be used as a light source. The light modulating unit (image light emitting unit) may be a transmissive liquid crystal panel or a DMD (Digital Mirror Device, digital mirror device).

(2) Modification 2
Further, the arrangement of the red light sensor 36R, the green light sensor 36G, and the blue light sensor 36B is not limited to the position shown in FIG. 1, but a yellow (Y) light source and a blue (B) light source. It may be a place where the brightness, specifically, the amount of light (light intensity) can be detected.

(3) Modification 3
In the above embodiment, the measurement value (optical sensor value) of the green light center 36G is not used in the light source state confirmation, but the present invention is not limited to this, and the red light optical center 36R and the blue light optical sensor are not limited thereto. In addition to the measurement value of 36B, the measurement value of the green light optical sensor 36G may be used. Further, instead of the measurement value of the red light optical sensor 36R, the measurement value of the green light optical sensor 36G may be used.

(4) Modification 4
Further, the arrangement of the BKD temperature sensor 53T and the excitation LD temperature sensor 60T is not limited to the position shown in FIG. 1, but may be any place where the temperature of each laser diode as a light source can be detected.

(5) Modification 5
The arrangement of the R light panel temperature sensor 33RT and the B light panel temperature sensor 33BT is not limited to the position shown in FIG. 1, and the temperature states of the light guide optical system and the reflective liquid crystal device can be grasped. Any place is acceptable.

(6) Modification 6
Further, the G light panel temperature sensor may be provided not on the R light panel temperature sensor 33RT but on the heat radiation fins 33G of the green reflective liquid crystal panel 4G. The red (R) light incident on the light guide optical system 3R and the reflective liquid crystal panel 4R is a part of the red light LR obtained by separating the yellow light LY emitted from the yellow light illumination device 52, and the light guide optical system. The green (G) light incident on the 3G and the reflective liquid crystal panel 4G is a part of the green light LG obtained by separating the yellow light LY emitted from the yellow light illumination device 52. For this reason, if the temperature state of the optical member arrangement region including at least one of the light guide optical system and the reflective liquid crystal panel is grasped, the temperature state of the other optical member arrangement region can be generally grasped.

(7) Modification 7
Further, in the above embodiment, the light source is confirmed with four types of currents, the first current I1 as the intermittent lighting current and the second current I2 to the fourth current I4 as the constant current driving current. It is not limited to. A plurality of currents may be used as the intermittent lighting current. Further, as the current for constant current driving, only two currents of the second current I2 that is the maximum current and I4 that is the minimum current may be used, or four or more currents may be used. If the number of currents is reduced, the measurement time can be shortened, and if the number of currents is increased, the accuracy of the light source control table can be increased.

(8) Modification 8
In the above embodiment, the light source control table is generated using the photosensor values of three predetermined currents (second current I2 to fourth current I4) in all constant current drive ranges corresponding to continuous lighting. This is described as an example. However, it is not necessary to use all predetermined constant current drive optical sensor values. For example, the light source control table may be generated using only the maximum current and the minimum current for constant current drive. The light source control table may be generated using the maximum current for current driving and the second largest current. That is, a light source control table using a maximum current and at least one current other than the maximum current among a plurality of predetermined currents in a range of all constant current driving currents corresponding to continuous lighting. May be generated.

(9) Modification 9
In the above embodiment, the optical sensor value is corrected using the temperature correction coefficient and the current correction coefficient, but the present invention is not limited to this. For example, when the luminance is switched and set according to a display scene such as a cinema mode, the number of rotations of the cooling fan included in the apparatus may be changed accordingly. In this case, since the temperature changes according to the number of lines set for the cooling fan, the optical sensor value may be corrected by separately providing a correction coefficient corresponding to the setting condition of the fan. That is, when a change is caused in the state of the light source according to the set condition, a correction coefficient corresponding to the change may be used. If the optical sensor value has little temperature dependency or current dependency, or if there is no temperature dependency or current dependency, the optical sensor value may not be corrected by these correction coefficients. .

(10) Modification 10
In the above embodiment, a current (also referred to as “drive current” or “supply current”) is described as an example of drive power (also referred to as “supply power”) for driving the light source, but a voltage (“drive voltage”) is described. Alternatively, it may be referred to as “supply voltage”.

(11) Modification 11
In addition, a program for executing each process of the control unit 63 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into the computer system and executed, whereby the control unit 63 is executed. The various processes described above may be performed.

  Here, the “computer system” may include an OS and hardware such as peripheral devices. Further, the “computer system” includes a homepage providing environment (or display environment) if the WWW system is used. “Computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable non-volatile memory such as a flash memory, a portable medium such as a CD ROM, and a storage such as a hard disk built in a computer system. Refers to the device.

  Further, the “computer-readable recording medium” refers to a volatile memory (for example, DRAM (Dynamic) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. Random Access Memory)) that holds a program for a certain period of time is also included. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

(12) Modification 12
The above embodiment has been described by taking a projector as an example, but it can also be applied to a general image display apparatus that does not include a projection optical system.

  The present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments and the modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

  3R, 3G, 3B Light guiding optical system 4R, 4G, 4B Reflective liquid crystal panel (light modulation unit, image light emitting unit) 5 Cross dichroic prism 6 Projection optical system 9 First lens array 10 Second lens array 11 Polarization conversion element 12 Superimposing lens 25 Dichroic mirror 26, 27, 28 Polarizing beam splitter (polarization separation element) 32R, 32G, 32B Condensing lens 33RT Panel temperature sensor for R light 33RT 33BT Temperature sensor for panel for B light 33BT 34R, 34G, 34B Polarized light Plate 36R Light sensor for red light 36G Light sensor for green light 36B Light sensor for blue light 37 First aperture (incident angle limiting member) 38 Second aperture (incident angle limiting member) 50, 50b Projector 51 Blue light illumination Equipment 52 for yellow light Bright device 53 Blue laser diode array 53T BLD temperature sensor 53T 54 Collimating lens 55 Condensing lens 56 Diffuser plate 57 Pickup lens 58 Parallelizing lens 59 Blue laser diode 60T Excitation LD temperature sensor 60T 61 Phosphor substrate 62 Excitation laser diode 63 control unit 64 image processing unit 65A drive control unit 65B storage unit 65a drive processing unit 65b current / light quantity characteristic deriving part 65c light source confirmation part 65d light quantity measurement part 65e temperature measurement part 65f current / light quantity characteristic LUT 65g duty / light quantity characteristic LUT 66 Liquid crystal drive unit 67 PWM signal generation unit 68 Laser diode drive unit for excitation 69 Blue laser diode drive unit 71 Light source 72 Light detection unit 73 Light source temperature detection unit 7 Panel temperature detector

Claims (9)

An image display device that emits image light representing an image and displays the image,
A light source;
A light source control unit for controlling the power supplied to the light source based on a power / light quantity characteristic indicating a relationship between the supplied power and the light quantity;
An image light emitting unit that emits the image light using light emitted from the light source;
A light amount measuring unit for measuring the amount of light emitted from the light source;
A power / light quantity characteristic deriving unit for deriving the power / light quantity characteristic based on a light quantity measurement value by the light quantity measurement unit;
With
The light source control unit controls the power supplied to the light source to change in order to a plurality of powers in a part of a range of power scheduled to be used in advance,
The light amount measurement unit measures the light amount for each of the plurality of electric powers,
The power / light quantity characteristic deriving unit derives the power / light quantity characteristic in a range of power to be used based on a light quantity measurement value for each of the plurality of electric powers. The image display device according to claim 1,
Among the plurality of powers, the maximum power is a power for intermittently lighting the light source, and at least a part of the power other than the maximum power is a power for continuously lighting the light source,
When the supply power is the maximum power, the light source control unit controls the supply power to be intermittent supply corresponding to the intermittent lighting,
The said light quantity measurement part measures the light quantity at the time of intermittent lighting by the intermittent supply of the said maximum electric power, and converts the measured light quantity measured value into the light quantity assumed at the time of continuous lighting. The image display device according to claim 1 or 2,
At least a temperature measuring unit for measuring the temperature of the light source;
The image display device, wherein the light quantity measurement unit corrects the light quantity measurement value based on a temperature measurement value obtained by the temperature measurement unit. The image display device according to any one of claims 1 to 3,
Comprising a plurality of the light sources,
The light amount measuring unit measures the amount of light emitted from each light source,
The light source control unit adjusts each power supply so that the amount of light emitted from each light source is balanced,
Among the plurality of powers, the maximum power is a power for intermittently lighting the light source, and at least a part of the power other than the maximum power is a power for continuously lighting the light source,
The balance adjustment amount of the supplied power is set based on a light quantity measurement value at the maximum power among the powers other than the maximum power. A projector,
A light source;
A light source control unit for controlling the power supplied to the light source based on a power / light quantity characteristic indicating a relationship between the supplied power and the light quantity;
A light modulation unit that modulates light emitted from the light source;
A projection optical system that projects the light modulated by the modulation unit;
A light amount measuring unit for measuring the amount of light emitted from the light source;
A power / light quantity characteristic deriving unit for deriving the power / light quantity characteristic based on a light quantity measurement value by the light quantity measurement unit;
With
The light source control unit controls the power supplied to the light source to change in order to a plurality of powers in a part of a range of power scheduled to be used in advance,
The light amount measurement unit measures the light amount for each of the plurality of electric powers,
The power / light quantity characteristic deriving unit derives the power / light quantity characteristic in a range of power to be used based on a light quantity measurement value for each of the plurality of electric powers. The projector according to claim 5, wherein
Among the plurality of powers, the maximum power is a power for intermittently lighting the light source, and at least a part of the power other than the maximum power is a power for continuously lighting the light source,
When the supply power is the maximum power, the light source control unit controls the supply power to be intermittent supply corresponding to the intermittent lighting,
The projector is characterized in that the light quantity measuring unit measures a light quantity at the time of intermittent lighting by intermittent supply of the maximum power, and converts the measured light quantity measurement value into a light quantity assumed at the time of continuous lighting. The projector according to claim 5 or 6, wherein
At least a temperature measuring unit for measuring the temperature of the light source;
The light quantity measurement unit corrects the light quantity measurement value based on a temperature measurement value obtained by the temperature measurement unit. A projector according to any one of claims 5 to 7,
Comprising a plurality of the light sources,
The light amount measuring unit measures the amount of light emitted from each light source,
The light source control unit adjusts each power supply so that the amount of light emitted from each light source is balanced,
Among the plurality of powers, the maximum power is a power for intermittently lighting the light source, and at least a part of the power other than the maximum power is a power for continuously lighting the light source,
The balance adjustment amount of the supplied power is set based on a light amount measurement value at the maximum power among the powers other than the maximum power. In an image display device that emits image light representing an image and displays an image, the amount of light emitted from the light source is supplied to the light source based on a power / light amount characteristic indicating a relationship between supply power and light amount. A control method for deriving the power / light quantity characteristic for controlling by adjusting power,
The image display device includes:
A light source;
A light source control unit for controlling power supplied to the light source based on the power / light quantity characteristic;
A light amount measuring unit for measuring the amount of light emitted from the light source;
A power / light quantity characteristic deriving unit for deriving the power / light quantity characteristic based on a light quantity measurement value by the light quantity measurement unit;
With
In the light source control unit, the power supplied to the light source is controlled so as to sequentially change to a plurality of powers in a part of a predetermined power range to be used,
In the light amount measurement unit, measure the light amount for each of the plurality of electric power,
The power / light quantity characteristic deriving unit derives the power / light quantity characteristic in a range of power to be used based on a light quantity measurement value for each of the plurality of electric powers.

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