JP2008228124A - Display unit and head-mounted display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid a decrease in manufacturing efficiency of a display unit 16 and then a decrease in mass-productivity of an HMD by enabling a single-eye display unit 16, to be readily expanded into a double-eye one. <P>SOLUTION: The display unit 16 is provided with a connection terminal which can be connected to another display unit 16 via an HMD cable 5c. The terminal comprises at least one of an output connection terminal 43 and an input connection terminal 51. One differential serial signal input, from a control unit 4 to the one display unit 16A, is branched inside it and supplied to a video display part 42 of the display unit 16A to display a picture on the video display part 42. The other differential serial signal is supplied to the output connection terminal 43 of the display unit 16A and inputs from the output connection terminal 43 to an input connection terminal 51 of the other display unit 16B via the HMD cable 5c, to display a picture on a video display part 42 of the display unit 16B. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes a display unit that is disposed in front of one eye of an observer and displays an image based on a differential serial signal, and a head-mounted display (hereinafter referred to as a head-mounted display) that is attached to the observer's head. , Also referred to as HMD).

  2. Description of the Related Art Conventionally, various HMDs have been proposed that provide a viewer with an image that is attached to the viewer's head and displayed on a display element (eg, LCD). For example, the HMD of Patent Document 1 includes a main body having a display element and a driving unit thereof, and an adapter unit that supplies a video signal to the main body via a cable. Two display elements are provided corresponding to both eyes, thereby enabling image observation with both eyes.

  By the way, in order to transmit a video signal (e.g., 8 bits), a synchronization signal (horizontal synchronization signal and vertical synchronization signal), a clock, power supply, and the like, the above cable usually has a bundle of about 20 signal lines. It consists of When the number of wires in the cable is large as described above, the radiation noise increases and the cost of the cable itself increases due to the special cable.

  Therefore, for example, in the HMDs of Patent Documents 2 and 3, a differential serial signal is transmitted from a control side unit (control unit) to a display side unit (display unit) via a cable, and the differential serial signal is converted into the differential serial signal. Based on this, video is displayed on the display unit. By using a differential serial signal, transmission of a video signal, a synchronization signal, a clock, and the like can be performed with two lines, so that the above disadvantages can be eliminated by reducing the number of lines in the cable.

JP-A-8-146717 JP-A-11-88800 JP 2003-172899 A

  By the way, conventionally, a display unit applied to a monocular HMD has a configuration that only assumes application to a monocular HMD, and does not have a configuration that assumes application to a binocular HMD. . For this reason, the display unit is manufactured separately for monocular use and for binocular use, resulting in problems that the production efficiency of the display unit is reduced and the mass productivity of the HMD is reduced.

  The present invention has been made to solve the above-described problems, and the object thereof is easily extended to binocular use in combination with other display units even if it is a monocular display unit. It is possible to provide a display unit capable of avoiding a decrease in manufacturing efficiency of the display unit, and thus a decrease in mass productivity of the HMD, and a binocular HMD configured using the display unit. It is in.

  The display unit of the present invention is a display unit that is disposed in front of one eye of an observer and displays an image based on a differential serial signal, and is connected to another display unit and a cable that are disposed in front of the other eye of the observer The connection terminals can be connected via an output connection terminal capable of outputting differential serial signals to other display units, and input of differential serial signals from other display units. It is characterized by comprising at least one of possible input connection terminals.

  According to the above configuration, the display unit displays an image based on the differential serial signal. Therefore, the number of lines in the cable between the display unit and another display unit is reduced to increase the radiation noise or the cable itself. An increase in cost can be avoided.

  Further, since the display unit is arranged in front of one eye of the observer, the observer can observe an image displayed on the display unit based on the differential serial signal with one eye. is there. At this time, since the display unit includes a connection terminal that can be connected to another display unit arranged in front of the other eye of the observer via a cable, a connection terminal (for example, an output connection terminal) is connected to the display unit. When the differential serial signal is output to another display unit via (), the other display unit can display an image based on the differential serial signal. Therefore, in this case, the observer can observe the images displayed on both display units with both eyes.

  When a differential serial signal from another display unit is input to the display unit via a connection terminal (for example, an input connection terminal), the display unit displays an image based on the differential serial signal. It becomes possible to do. At this time, if the other display units are configured to display an image based on the same differential serial signal, the observer can observe the images displayed on both display units with both eyes.

  As described above, since the display unit includes the connection terminal (at least one of the output connection terminal and the input connection terminal), even if the display unit is for a single eye (a display unit dedicated to observation with a single eye). However, it can be easily expanded for binocular use in combination with other display units, and a reduction in manufacturing efficiency of the display unit, and a reduction in mass productivity of the HMD can be avoided.

  The display unit of the present invention further includes an input terminal to which a differential serial signal from the control unit is input, and a video display unit that displays an image based on the differential serial signal, and the connection terminal is for the output The differential serial signal input from the control unit to the input terminal is branched inside the display unit, and one differential serial signal is supplied to the video display unit, and the other The differential serial signal may be supplied to the output connection terminal. Hereinafter, the display unit having this configuration is also referred to as a first display unit.

  According to the above configuration, the differential serial signal from the control unit is input to the input terminal and then branched inside the display unit. One differential serial signal is supplied to the video display unit, and video is displayed on the video display unit based on the differential serial signal. On the other hand, since the other differential serial signal is supplied to the output connection terminal, for example, when the output connection terminal is connected to another display unit via a cable, the other differential serial signal is output to the output connection terminal. Are output to other display units. Thereby, in other display units, it becomes possible to display an image based on the differential serial signal. Therefore, when the display unit is combined with another display unit, it is possible to reliably display an image on both sides, and it is possible to reliably configure an HMD capable of observing images with both eyes.

  The display unit of the present invention further includes a video display unit that displays video based on a differential serial signal, the connection terminal is configured by the input connection terminal, and the video display unit is connected to the control unit. A configuration may be adopted in which an image is displayed based on a differential serial signal input to the input connection terminal via another display unit. Hereinafter, the display unit having this configuration is also referred to as a second display unit.

  According to said structure, a video is displayed on the video display part of the said display unit based on the differential serial signal input into the connection terminal for input via another display unit from a control unit. Therefore, if another display unit that is a supply source of the differential serial signal to the display unit displays an image based on the same differential signal, an HMD capable of observing images with both eyes is configured. be able to.

  The display unit of the present invention further includes an input terminal capable of inputting a differential serial signal from the control unit, and a video display unit for displaying video based on the differential serial signal, and the connection terminal is for the output When the differential serial signal from the control unit is input to the input terminal, the differential serial signal is branched inside the display unit. The differential serial signal is supplied to the video display unit, the other differential serial signal is supplied to the output connection terminal, and the differential serial signal from the control unit is connected to the input via the other display unit. When the signal is input to the terminal, the differential serial signal may be supplied to the video display unit. Hereinafter, the display unit having this configuration is also referred to as a third display unit.

  According to the above configuration, when the differential serial signal from the control unit is input to the input terminal, the differential serial signal is internally branched and one differential serial signal is supplied to the video display unit. Thus, the video display unit can display a video based on the differential serial signal. The other differential serial signal is supplied to the output connection terminal. For example, if the output connection terminal is connected to another display unit via a cable, the other differential serial signal is output to the output connection terminal. Are output to other display units. Thereby, in other display units, it becomes possible to display an image based on the differential serial signal. Therefore, the observer can observe the images displayed on both display units with both eyes.

  In addition, when the differential serial signal from the control unit is input to the input connection terminal via another display unit, the differential serial signal is supplied to the video display unit. An image can be displayed based on the serial signal. Therefore, if another display unit is configured to display an image based on the same differential signal as that supplied to the display unit, the observer can observe the images displayed on both display units with both eyes. Is possible.

  Thus, according to the configuration of the display unit, even when the differential serial signal from the control unit is directly input to the input terminal, it is input to the input connection terminal via another display unit. Even in this case, an image can be displayed based on the differential serial signal.

  Further, according to the configuration of the display unit, it is possible to realize an HMD capable of observing images with both eyes by combining two display units having the same configuration. That is, the output connection terminal of one display unit and the input connection terminal of the other display unit are connected by a cable, and the differential serial signal from the control unit is input to the input terminal of one display unit. Thus, an HMD capable of displaying images on both display units and capable of observing images with both eyes can be configured by the same operation as described above.

  At this time, since both of the two display units are provided with the above-described three terminals of the input terminal, the input connection terminal, and the output connection terminal, either display unit can be used for the left eye or the right eye. It can be used (the output connection terminal of either display unit may be connected to the input connection terminal of another display unit). As described above, the two display units can be used without being distinguished from each other in correspondence with the left and right eyes, so that the display unit and thus the HMD can be mass-produced easily, and the cost can be reduced easily.

  The display unit of the present invention is a display unit that is disposed in front of one eye of an observer and displays an image based on a differential serial signal, and includes an input terminal to which a differential serial signal from a control unit is input. The input terminal is connected to one of a plurality of output ends of a branch cable for supplying a differential serial signal from the control unit in parallel with another display unit. Hereinafter, the display unit having this configuration is also referred to as a fourth display unit.

  According to the above configuration, since the display unit displays an image based on the differential serial signal, it is possible to reduce the number of lines in the branch cable and avoid an increase in radiation noise and an increase in the cost of the cable itself. it can.

  Also, if two display units are used and a plurality of output terminals of the branch cable are connected to the input terminals of each display unit, a differential serial signal is sent from the control unit to the input terminal of each display unit via the branch cable. It is possible to input in parallel. Thereby, each display unit can display an image based on the inputted differential serial signal. Therefore, the observer can observe the images displayed on both display units with both eyes.

  In addition, the display unit is originally for a single eye placed in front of one eye of the observer, but according to the above configuration, it can be used for a binocular by combining two display units for a single eye. It becomes. As described above, since the monocular display unit can be easily expanded to both eyes, it is possible to avoid a decrease in the manufacturing efficiency of the display unit and, in turn, a decrease in the mass productivity of the HMD.

  The display unit of the present invention is a signal based on the adjustment data when the adjustment data stored in the storage means is input and set, and the adjustment data used for adjusting the display of the video. And an output unit that outputs a signal necessary for display.

  According to the above configuration, when the adjustment data stored in the storage unit (for example, EEPROM) is input and set in the output unit (for example, DAC), the output unit is a signal based on the set adjustment data. Outputs signals necessary for display. For example, if the adjustment data is data for adjusting the luminous intensity (brightness, intensity) of the light source (LED), a signal (drive voltage) based on the adjustment data is output from the output unit. Accordingly, for example, a drive unit that drives the LED (for example, a constant current circuit that converts voltage into current) supplies the LED with current corresponding to the drive voltage, thereby causing the LED to emit light in a state in which the luminous intensity is adjusted. be able to.

  As the adjustment data, for example, data for register setting of the LCD (data for adjusting contrast, brightness, etc. in the LCD) can be assumed, but even in this case, from the output unit Since a signal based on the adjustment data is output, for example, a driving unit that drives the LCD drives the LCD based on a signal supplied from the output unit, and the LCD is adjusted in contrast and brightness. Video can be displayed.

  As described above, since the display unit includes the storage unit and the output unit, adjustment data unique to each display unit can be stored in the storage unit and can be written in the output unit. Thus, when the HMD is configured by combining the display unit and the control unit, it is not necessary to reset adjustment data for each display unit to be used. As a result, the production efficiency of HMD can be improved.

  In addition, since each display unit has its own adjustment data, even when only the display unit is shipped as a single unit, the display unit to be used for each combination with the control unit at the shipping destination (for each HMD). It is possible to realize an HMD capable of displaying a good video based on the adjustment data.

  The display unit of the present invention further includes a light source, a display element that displays an image by modulating light from the light source, and a drive unit that emits the light source based on a signal output from the output unit, and the adjustment The data may be data for adjusting the light intensity of the light source.

  When the adjustment data is data for adjusting the luminous intensity of light emitted from a light source (for example, LED), when a signal (driving voltage) based on the adjustment data is output from the output unit, the driving unit (for example, a constant current circuit) ) Causes the light source to emit light based on the signal. As a result, the light source can emit light with the luminous intensity adjusted, and the brightness (luminance) of the image displayed on the display element can be adjusted.

  The HMD of the present invention includes a plurality of display units that display video based on a differential serial signal, and a control unit that supplies a differential serial signal to any one of the display units. The first display unit of the present invention and the second display unit of the present invention described above, the output connection terminal of the first display unit, and the input connection terminal of the second display unit And are connected via a cable.

  According to the above configuration, the differential serial signal from the control unit is input to the input terminal of the first display unit and then branched inside. One differential serial signal is supplied to the video display unit, and video is displayed on the video display unit based on the differential serial signal.

  On the other hand, the other differential serial signal is supplied to the output connection terminal, and is input from the output connection terminal to the input connection terminal of the second display unit via the cable. Thereby, in the second display unit, the video is displayed on the video display unit based on the input differential serial signal. Accordingly, an HMD capable of observing images with both eyes can be realized by combining two display units.

  The HMD of the present invention includes a plurality of display units that display video based on a differential serial signal, and a control unit that supplies a differential serial signal to any one of the display units. The third display unit of the present invention is composed of two, the input terminal of one display unit is connected to the control unit via a cable, and the output connection terminal of the display unit is the other The display unit is connected to an input connection terminal of the display unit via a cable.

  According to the above configuration, when the differential serial signal from the control unit is input to the input terminal of one display unit (third display unit), the differential serial signal is branched internally, A dynamic serial signal is supplied to the video display unit. Thereby, in one display unit, an image is displayed by the image display unit based on the differential serial signal. In one display unit, the other differential serial signal is supplied to the output connection terminal. The output connection terminal is connected to the input connection terminal of the other display unit (third display unit) and the cable. Therefore, in the other display unit, an image is displayed on the image display unit based on the differential serial signal input via the input connection terminal. Therefore, it is possible to realize an HMD capable of observing images displayed on both display units with both eyes.

  The HMD of the present invention has two fourth display units of the present invention described above, a branch cable in which a plurality of output ends are connected to input terminals of each display unit, and a difference between each display unit via the branch cable. And a control unit for supplying a dynamic serial signal.

  According to the above configuration, since the differential serial signal from the control unit is input in parallel to the input terminal of each display unit (fourth display unit) via the branch cable, it is input to each display unit. The video can be displayed based on the differential serial signal. Therefore, it is possible to realize an HMD capable of observing images displayed on both display units with both eyes.

  In the HMD of the present invention, when the plurality of display units described above are input and set with storage means for storing adjustment data used for video display adjustment and the adjustment data stored in the storage means, And an output unit that outputs a signal based on the adjustment data and necessary for display, and the control unit is connected to the storage unit and the output unit via a cable that transmits a differential serial signal. Each display unit includes a control unit that transmits a control signal. Based on the control signal, each display unit writes the adjustment data to the storage unit, reads the adjustment data written to the storage unit, writes it to the output unit, and sets it. May be performed.

  According to said structure, a control signal is transmitted to the memory | storage means and output part of a display unit from the control part of a control unit via the cable which transmits a differential serial signal. In each display unit, based on this control signal, an operation of writing the adjustment data in the storage unit and an operation of reading out the adjustment data written in the storage unit, writing it in the output unit, and setting it are performed. As the adjustment data, for example, data for adjusting the luminous intensity of the light source and data for setting the LCD register (data for adjusting contrast, brightness, etc. in the LCD) can be assumed. Since the output unit outputs a signal based on the set adjustment data and necessary for display, each display unit can display a good video based on the signal.

  Also, when using a differential serial signal, the transmission of the differential serial signal is unidirectional from the control unit to each display unit, so the control unit in the control unit is stored in the storage means in each display unit. Adjustment data cannot be read. However, as described above, by sending a control signal from the control unit to each display unit via a cable that transmits a differential serial signal, the adjustment data is written to and read from the storage means of each display unit, and The read adjustment data can be written to the output unit and set. Therefore, even if the communication from the control unit to each display unit is unidirectional, it is possible to adjust the display of the video based on the specific adjustment data for each display unit.

  Since the display unit of the present invention displays an image based on the differential serial signal, the number of wires in the cable to be used can be reduced to avoid an increase in radiation noise and an increase in the cost of the cable itself. In addition, since an HMD capable of observing images with both eyes can be easily configured using two monocular display units, there is no need to manufacture the display unit separately for monocular and binocular. Thus, it is possible to avoid a decrease in manufacturing efficiency of the display unit, and hence a decrease in mass productivity of the HMD.

[Embodiment 1]
An embodiment of the present invention will be described below with reference to the drawings.

(1. Configuration of HMD)
FIG. 2A is a plan view showing the overall configuration of the HMD according to this embodiment, and FIG. 2B is a front view of the HMD. The HMD includes two video display devices 1 (1R and 1L), support means 2, a video source 3, and a control unit 4. The video source 3 and the control unit 4 are connected via the AV cable 5a, and the control unit 4 and the video display device 1R are connected via the HMD cable 5b, and the video display device 1R and the video display are displayed. The device 1L is connected via an HMD cable 5c.

  The video display devices 1R and 1L allow an observer to observe an external image in a see-through manner, display an image, and provide the image as a virtual image to the observer. In front of the right eye and the left eye of the observer Respectively. In the video display devices 1R and 1L, portions corresponding to the right eye lens and the left eye lens of the glasses are configured by bonding an eyepiece prism 21 (see FIG. 3) and a deflection prism 22 (see FIG. 3), which will be described later. Has been.

  The support means 2 supports the video display devices 1R and 1L in front of the right and left eyes of the observer, and includes a bridge 6, a frame 7, a temple 8, a nose pad 9, and an earphone 10. have. The nose pad 9 is supported by the bridge 6, and the earphone 10 is connected to the video display device 1 via a cable.

  The frame 7, the temple 8, the nose pad 9, and the earphone 10 are provided in a pair on the left and right sides. However, when these are distinguished on the left and right, the right frame 7R, the left frame 7L, the right temple 8R, the left temple 8L, It is expressed as a nose pad 9R, a left nose pad 9L, a right earphone 10R, and a left earphone 10L.

  The video display devices 1R and 1L are connected by a bridge 6. The right temple 8R is rotatably supported by the right frame 7R, and is connected to the video display device 1R via the right frame 7R. Similarly, the left temple 8L is rotatably supported by the left frame 7L, and is connected to the video display device 1L via the left frame 7L.

  The video source 3 is a device capable of outputting a video signal to the outside via the AV cable 5a, and is configured by, for example, a DVD player. The control unit 4 is a unit that converts the video signal supplied from the video source 3 into a differential serial signal and supplies the differential serial signal to the video display devices 1R and 1L via the HMD cables 5b and 5c. The control unit 4 includes a power switch 4a for turning on / off the power, a video adjustment input unit 4b for instructing video display adjustment (for example, brightness and contrast adjustment), and an audio volume. The audio adjustment input unit 4c is provided, and the detailed configuration thereof will be described later.

  When the observer uses the HMD, the right temple 8R and the left temple 8L are brought into contact with the right and left heads of the observer, and the nose pad 9 is placed on the nose of the observer so as to wear general glasses. The HMD is attached to the observer's head. In this state, when the video is displayed on the video display devices 1R and 1L, the observer can observe each display video of the video display devices 1R and 1L as a virtual image with both eyes, and the video display devices 1R and 1L can be viewed. Thus, it is possible to observe the outside world image with see-through.

  As described above, the HMD of the present embodiment includes the video display devices 1R and 1L and the support means 2 that supports the video display devices 1R and 1L in front of the viewer's eyes. Images provided from the devices 1R and 1L can be observed hands-free. Details of the video display devices 1R and 1L will be described below.

(2. Configuration of video display device)
FIG. 3 is a cross-sectional view showing a schematic configuration of the video display device 1 (1R · 1L). The video display device 1 includes a light source 11, a unidirectional diffuser 12, a condenser lens 13, a display element 14, and an eyepiece optical system 20. The light source 11, the one-way diffusing plate 12, the condensing lens 13, and the display element 14 are accommodated in a casing 15, and constitute a display unit 16 that displays an image based on a differential serial signal described later. . A more detailed configuration of the display unit 16 will be described later. In addition, a part of an eyepiece prism 21 described later of the eyepiece optical system 20 is also located in the housing 15.

  For convenience of explanation below, directions are defined as follows. First, an axis that optically connects the center of the display area of the display element 14 and the center of the optical pupil E formed by the eyepiece optical system 20 is defined as an optical axis. The optical axis direction when the optical path from the light source 11 to the optical pupil E is developed is taken as the Z direction. In addition, a direction perpendicular to an incident surface of an optical axis to a hologram optical element 23 to be described later of the eyepiece optical system 20 is defined as an X direction, and a direction perpendicular to the ZX plane is defined as a Y direction. Note that the incident surface of the optical axis to the hologram optical element 23 refers to a plane including the optical axis of incident light and the optical axis of reflected light in the hologram optical element 23, that is, the YZ plane. Hereinafter, the incident surface is simply referred to as an incident surface or an optical axis incident surface.

  The light source 11 illuminates the display element 14. For example, the light source 11 is 462 ± 12 nm (B light), 525 ± 17 nm (G light), 635 ± 11 nm (R It is composed of RGB-integrated LEDs that emit light in three wavelength bands. The peak wavelength for each color of the light source 11 is set in the vicinity of the peak wavelength of diffraction efficiency, which will be described later, of the hologram optical element 23, thereby improving the light utilization efficiency.

  Since the light source 11 is composed of LEDs that emit RGB light, the light source 11 can be realized at low cost and a color image can be displayed on the display element 14 when the display element 14 is illuminated. And the color image can be provided to the viewer. Further, since each LED has a narrow emission wavelength width, the use of a plurality of such LEDs enables high color reproducibility and bright image display.

  The unidirectional diffuser plate 12 diffuses the light emitted from the light source 11, but the degree of diffusion differs depending on the direction. More specifically, the unidirectional diffuser 12 diffuses incident light in the X direction by about 40 ° and diffuses incident light in the Y direction by about 0.5 °.

  The condensing lens 13 is composed of a cylinder lens that condenses the light diffused by the unidirectional diffusing plate 12 in the Y direction, and is arranged so that the diffused light efficiently forms the optical pupil E. .

  The display element 14 displays an image by modulating the light emitted from the light source 11 in accordance with image data, and is configured by a transmissive liquid crystal display element having pixels in a matrix in which light is transmitted. Has been. The display element 14 is arranged such that the long side direction of the rectangular display region is the X direction and the short side direction is the Y direction. The display element 14 may be a reflective type. As the reflective display element 14, for example, a reflective liquid crystal display element or DMD (Digital Micromirror Device; manufactured by Texas Instruments Inc., USA) can be used.

  The eyepiece optical system 20 is a magnification optical system that provides an observer with a magnified virtual image of the display image of the display element 14, and includes an eyepiece prism 21 (first transparent substrate), a deflection prism 22 (second transparent substrate), and the like. The hologram optical element 23 is included.

  The eyepiece prism 21 totally reflects the image light from the display element 14 on two opposing surfaces and guides it to the observer's pupil through the hologram optical element 23, while transmitting external light to the observer's pupil. For example, it is made of an acrylic resin together with the deflecting prism 22. The eyepiece prism 21 is formed in a shape in which the lower end portion of the parallel plate is thinned toward the lower end so as to be wedge-shaped, and the upper end portion thereof is thickened toward the upper end. Further, the eyepiece prism 21 is joined to the deflection prism 22 with an adhesive so as to sandwich the hologram optical element 23 disposed at the lower end thereof.

  The deflection prism 22 is configured by a substantially U-shaped parallel plate in plan view, and is integrated with the eyepiece prism 21 when bonded to the lower end portion and both side surface portions (left and right end surfaces) of the eyepiece prism 21. It becomes a substantially parallel plate. By joining the deflecting prism 22 to the eyepiece prism 21, it is possible to prevent distortion in the external image observed by the observer via the eyepiece optical system 20.

  That is, for example, when the deflecting prism 22 is not joined to the eyepiece prism 21, the external light is refracted when passing through the wedge-shaped lower end portion of the eyepiece prism 21, so that the external image observed through the eyepiece prism 21 is distorted. Arise. However, the deflection prism 22 is joined to the eyepiece prism 21 to form an integral substantially parallel plate, so that the deflection when the external light passes through the wedge-shaped lower end of the eyepiece prism 21 is canceled by the deflection prism 22. Can do. As a result, it is possible to prevent distortion in the external image observed through the see-through.

  Each surface of the eyepiece prism 21 and the deflecting prism 22 may be a flat surface or a curved surface. If each surface of the eyepiece prism 21 and the deflecting prism 22 is a curved surface, the eyepiece optical system 20 can also have a function as a correcting eyeglass lens.

  The hologram optical element 23 diffracts and reflects the image light (light having a wavelength corresponding to the three primary colors) emitted from the display element 14 and enlarges the image displayed on the display element 14 as a virtual image on the observer's pupil. It is a volume phase type reflection hologram to be guided. The hologram optical element 23 has, for example, three wavelength ranges of 465 ± 5 nm (B light), 521 ± 5 nm (G light), and 634 ± 5 nm (R light) with a peak wavelength of diffraction efficiency and a wavelength width of half value of diffraction efficiency. The light is diffracted (reflected). Here, the peak wavelength of diffraction efficiency is the wavelength at which the diffraction efficiency reaches a peak, and the wavelength width at half maximum of the diffraction efficiency is the wavelength width at which the diffraction efficiency is at half the peak of the diffraction efficiency. It is.

  The reflection-type hologram optical element 23 has high wavelength selectivity, and only diffracts and reflects light having a wavelength in the wavelength range (near the exposure wavelength). Through the hologram optical element 23, a high external light transmittance can be realized.

  Further, the hologram optical element 23 has an axially asymmetric positive optical power. That is, the hologram optical element 23 has the same function as an aspherical concave mirror having positive power. Thereby, the degree of freedom of arrangement of each optical member constituting the apparatus can be increased, and the apparatus can be easily reduced in size, and an image with good aberration correction can be provided to the observer.

(3. Operation of video display device)
Next, the operation of the video display device 1 having the above configuration will be described. The light emitted from the light source 11 is diffused by the unidirectional diffusion plate 12, condensed by the condenser lens 13, and enters the display element 14. The light incident on the display element 14 is modulated for each pixel based on the image data and is emitted as video light. That is, a color image is displayed on the display element 14.

  The image light from the display element 14 enters the eyepiece prism 21 of the eyepiece optical system 20 from its upper end surface, is totally reflected a plurality of times by two opposing surfaces, and enters the hologram optical element 23. The light incident on the hologram optical element 23 is reflected there and reaches the optical pupil E. At the position of the optical pupil E, the observer can observe an enlarged virtual image of the image displayed on the display element 14.

  On the other hand, the eyepiece prism 21, the deflecting prism 22, and the hologram optical element 23 transmit almost all of the outside light, so that the observer can observe the outside world image through them. Therefore, the virtual image of the image displayed on the display element 14 is observed while being overlapped with a part of the external image.

  As described above, in the video display device 1, the video light emitted from the display element 14 is guided by total reflection in the eyepiece prism 21 and guided to the observer's pupil via the hologram optical element 23. Similar to the spectacle lens, the thickness of the eyepiece prism 21 and the deflecting prism 22 can be about 3 mm, and the video display device 1 can be reduced in size and weight. Further, by using the eyepiece prism 21 that totally reflects the image light from the display element 14, a high external light transmittance can be secured and a bright external image can be provided to the observer.

  Further, the volume phase type reflection type hologram optical element 23 has a narrow diffraction efficiency half-value wavelength width and a high diffraction efficiency. By using such a hologram optical element 23, a color image with high color purity and high brightness can be obtained. In addition to providing high external light transmittance, the observer can observe a bright external image. Moreover, since the conjugate relationship between the light source 11 and the optical pupil E is not changed, the wavelength of the image light does not change, and an image with high color reproducibility can be provided.

  Further, as can be seen from the above description, the hologram optical element 23 functions as a combiner that guides the image light and the external light from the display element 14 to the observer's pupil at the same time. As a result, the observer can simultaneously observe the image provided from the display element 14 and the external image via the hologram optical element 23.

(4. Detailed configuration of control unit and display unit)
Next, detailed configurations of the control unit 4 and the display unit 16 will be described. FIG. 4 is a block diagram showing the configuration of the main part of the control unit 4 and the main part of the display unit 16.

  For the sake of convenience in the following description, when it is desired to particularly distinguish the two display units 16 arranged corresponding to the eyes of the observer, one is the display unit 16A (first display unit) and the other is The display unit 16B (second display unit) is used. That is, one of the display units 16A and 16B is arranged in front of the right eye of the observer, and the other is arranged in front of the left eye. Also, the thick arrows in FIG. 4 indicate that signals are flowing in parallel.

  The control unit 4 includes a battery 31, a power circuit 32, an NTSC decoder 33, an LVDS transmitter 34, a microprocessor 35, an amplifier / volume, in addition to the power switch 4a, the video adjustment input unit 4b, and the audio adjustment input unit 4c. The adjustment unit 36 and connection terminals 37, 38, and 39 are provided.

  The battery 31 outputs a predetermined voltage (e.g., 3.7 V, GND) to the power supply circuit 32 in order to drive each part of the control unit 4 and each part of the display unit 16. When the power switch 4a is turned on, the power supply circuit 32 generates a voltage (for example, 5V, 2.5V, GND) suitable for driving each part of the control unit 4 and each part of the display unit 16 from the output voltage of the battery 31. Generate. The voltage generated by the power supply circuit 32 is output to the display unit 16A via the connection terminal 37.

  The NTSC decoder 33 converts an analog video signal (VIDEO signal) supplied from the video source 3 (see FIG. 2 (a)) into a digital signal (for example, 8 bits), a clock and a synchronization signal (horizontal synchronization signal, Vertical sync signal). These signals are output from the NTSC decoder 33 to the LVDS transmitter 34 in parallel.

  The LVDS transmitter 34 converts a signal input in parallel from the NTSC decoder 33 into a serial signal. By this parallel / serial conversion, a 1 or 0 signal is output as a differential serial signal from the LVDS transmitter 34 to the display unit 16A via the connection terminal 38.

  The microprocessor 35 is a control unit that outputs a control signal (serial signal) for controlling operations of a display element driving circuit 48 and a light source current adjusting circuit 49 described later of the display unit 16 to the LVDS transmitter 34. This control signal includes a serial clock SCLK, serial data SDAT, and serial enable SCE. The serial enable SCE includes a serial enable SCE1 for selecting the display element driving circuit 48 and a serial enable SCE2 for selecting the light source current adjusting circuit 49.

  Further, the microprocessor 35 outputs a signal based on the input from the video adjustment input unit 4b to the LVDS transmitter 34, reflects the adjustment contents in the output signal from the LVDS transmitter 34, and also uses the audio adjustment input unit 4c. A signal based on the input is sent to the amplifier / volume controller 36.

  The amplifier / volume controller 36 amplifies the left and right audio signals (AUDIO / R, AUDIO / L) based on the input signal from the microprocessor 35 and adjusts the audio volume. The audio signal adjusted by the amplifier / volume adjusting unit 36 is output to the display unit 16 </ b> A via the connection terminal 39.

  Next, the detailed configuration of the display units 16A and 16B will be described with reference to FIGS. FIG. 1 is a simplified block diagram of the configuration of the HMD shown in FIG. The display unit 16 </ b> A includes an input terminal 41, a video display unit 42, and an output connection terminal 43. The input terminal 41, the input terminal of the video display unit 42 (the input terminal of the LVDS receiver 47 described later), and the output connection terminal 43 are electrically connected inside the display unit 16A.

  The input terminal 41 is a connection terminal that can be connected to the connection terminal 38 of the control unit 4 via the HMD cable 5 b, and a differential serial signal from the control unit 4 is input to the input terminal 41. Note that the HMD cable 5b has a plurality of signal lines. The video display unit 42 displays video based on the differential serial signal, and the detailed configuration thereof will be described later.

  The output connection terminal 43 is a connection terminal that can be connected to the input connection terminal 51 described later of the display unit 16B via the HMD cable 5c. The HMD cable 5c has a plurality of signal lines. In the present embodiment, when a differential serial signal from the control unit 4 is input to the input terminal 41, the differential serial signal is branched inside the display unit 16A, and one of the signals is supplied to the video display unit 42. The other is supplied to the output connection terminal 43. Thereby, it is possible to output the other differential serial signal from the output connection terminal 43 to the other display unit 16B via the HMD cable 5c.

  The display unit 16A further includes connection terminals 44, 45, and 46. The connection terminal 44 is a connection terminal that can be connected to the connection terminal 37 of the control unit 4 via the HMD cable 5b. The voltage supplied from the power supply circuit 32 via the connection terminal 37 is supplied to each part of the display unit 16A via the HMD cable 5b and the connection terminal 44, and also the display unit via the connection terminal and the HMD cable 5c (not shown). 16B is also supplied to drive each part of the display units 16A and 16B.

  The connection terminal 45 is a connection terminal that can be connected to the connection terminal 39 of the control unit 4 via the HMD cable 5b. The connection terminal 46 is a connection terminal that can be connected to the terminal of the earphone 10. These connection terminals 45 and 46 are electrically connected inside the display unit 16A. Therefore, when the terminal of the earphone 10 is connected to the connection terminal 46, the audio signal output from the connection terminal 39 of the control unit 4 is input to the earphone 10 through the HMD cable 5b and the connection terminals 45 and 46 in this order. .

  Next, a detailed configuration of the video display unit 42 will be described. The video display unit 42 includes an LVDS receiver 47, a display element driving circuit 48, and a light source current adjusting circuit 49 in addition to the light source 11 and the display element 14 described above.

  The LVDS receiver 47 converts an input differential serial signal into a parallel signal. Of the signals output in parallel from the LVDS receiver 47, the video signal, clock, and synchronization signal are input to the display element driving circuit 48. Control signals (SCLK, SDAT, SCE) included in the output signal from the LVDS receiver 47 are input to both the display element driving circuit 48 and the light source current adjusting circuit 49. However, the serial enable SCE1 is input only to the display element driving circuit 48, and the serial enable SCE2 is input only to the light source current adjusting circuit 49.

  The display element driving circuit 48 drives the display element 14 based on signals output in parallel from the LVDS receiver 47. Based on the control signal supplied from the LVDS receiver 47, the light source current adjustment circuit 49 adjusts the currents that flow through the respective RGB LEDs that constitute the light source 11, and adjusts the RGB luminous intensity (luminance, light intensity).

  Thus, the display element drive circuit 48 drives the display element 14, and the light source current adjustment circuit 49 adjusts the RGB light intensity in the light source 11, so that the video display unit 42 uses the light from the light source 11 to display the display element 14. When an image is illuminated, an image with good white balance can be displayed.

  On the other hand, the display unit 16 </ b> B includes an input connection terminal 51 and a video display unit 42.

  The input connection terminal 51 is a connection terminal that can be connected to the output connection terminal 43 of the other display unit 16A via the HMD cable 5c. Therefore, it is possible to input a differential serial signal from the control unit 4 to the input connection terminal 51 via the other display unit 16A.

  The video display unit 42 of the display unit 16B displays video based on the differential serial signal input to the input connection terminal 51. The detailed configuration thereof is the same as that of the video display unit 42 of the display unit 16A. It is exactly the same.

  According to said structure, the differential serial signal from the control unit 4 is input into the display unit 16A via the HMD cable 5b and the input terminal 41, and is branched in the inside. One differential serial signal is supplied to the video display unit 42 of the display unit 16A, and the video display unit 42 displays the video.

  The other differential serial signal is supplied to the output connection terminal 43 of the display unit 16A, and is input from the output connection terminal 43 to the input connection terminal 51 of the display unit 16B via the HMD cable 5c. The differential serial signal input to the input connection terminal 51 of the display unit 16B is supplied to the video display unit 42 of the display unit 16B, and the video is displayed on the video display unit 42.

  As described above, the display unit 16 </ b> A displays an image based on the differential serial signal from the control unit 4. The display unit 16A is a connection terminal that can be connected to another display unit 16B via the HMD cable 5c, and has an output connection terminal 43 that can output a differential serial signal to the other display unit 16B. Therefore, when the differential serial signal is output from the display unit 16A to the other display unit 16B via the output connection terminal 43, the other display unit 16B displays an image based on the differential serial signal. It becomes possible. Therefore, the observer can observe the images displayed on both display units 16A and 16B with both eyes.

  The display unit 16B is a connection terminal that can be connected to another display unit 16A via the HMD cable 5c, and has an input connection terminal 51 that can input a differential serial signal from the other display unit 16A. Therefore, when a differential serial signal from another display unit 16A is input to the display unit 16B via the input connection terminal 51, the display unit 16B displays an image based on the differential serial signal. It is possible to display. Therefore, when the other display unit 16A displays an image based on the same differential serial signal as in the present embodiment, the observer observes the image displayed on both the display units 16A and 16B with both eyes. It becomes possible to do.

  Thus, since the display units 16A and 16B have the above-described connection terminals (the output connection terminal 43 or the input connection terminal 51), even when the display units 16A and 16B are manufactured for monocular use, The display units 16B and 16A can be easily expanded for both eyes (can be used as the binocular display unit 16), and the production efficiency of the display unit 16 is reduced. Can be avoided.

  In addition, since the display units 16A and 16B display video based on the differential serial signal as described above, the number of signal lines in the HMD cables 5b and 5c to be used can be surely reduced. For example, in this embodiment, signal lines for supplying a power supply voltage and transmitting audio signals are required in addition to transmitting differential serial signals. Therefore, a general-purpose Ethernet (registered trademark) cable (LAN cable) can be used as the HMD cables 5b and 5c. As a result, an increase in radiation noise and an increase in the cost of the cable itself can be avoided.

  The display unit 16A includes an input terminal 41 to which a differential serial signal from the control unit 4 is input, and a video display unit 42 that displays an image based on the differential serial signal. The differential serial signal input to is branched in the display unit 16A, one differential serial signal is supplied to the video display unit 42 of the display unit 16A, and the other differential serial signal is output connection. It is supplied to the terminal 43. Thus, as described above, based on the differential serial signal from the control unit 4, it is possible to reliably display images on both the display units 16A and 16B, and to enable image observation with both eyes. Can be reliably configured.

  In addition, the display unit 16B has a video display unit 42 that displays video based on the differential serial signal. The video display unit 42 is connected for input from the control unit 4 via another display unit 16A. Since the video is displayed based on the differential serial signal input to the terminal 51, when the other display unit 16A displays the video based on the same differential signal as in the present embodiment, the video observation with both eyes is performed. Therefore, it is possible to reliably configure an HMD that can be used.

  The HMD of the present embodiment includes a plurality of display units 16A and 16B that display video based on the differential serial signal, and a control unit 4 that supplies the differential serial signal to the display unit 16A. The output connection terminal 43 of the display unit 16A and the input connection terminal 51 of the display unit 16B are connected via the HMD cable 5c. Thereby, in the display unit 16A, an image is displayed based on the differential serial signal input from the control unit 4 via the input terminal 41, and in the display unit 16B, the output connection terminal 43 of the display unit 16A is connected to the HMD cable. An image is displayed based on the differential serial signal input via 5c and the input connection terminal 51. Therefore, it is possible to realize an HMD capable of observing images displayed on both display units 16A and 16B with both eyes.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to the drawings. For convenience of explanation below, the same components as those in the first embodiment are denoted by the same member numbers, and description thereof is omitted.

  FIG. 5 is a block diagram showing a simplified configuration of the HMD of the present embodiment. In this HMD, two display units 16 (third display units) having the same configuration are connected by an HMD cable 5c, and one display unit 16 and the control unit 4 are connected by an HMD cable 5b. Hereinafter, differences from the first embodiment will be described.

  Each display unit 16 includes an input terminal 41, an output connection terminal 43, an input connection terminal 51, and a video display unit 42. In other words, in the present embodiment, each display unit 16 includes two connection terminals, that is, the output connection terminal 43 and the input connection terminal 51. In each display unit 16, the input terminal 41, the output connection terminal 43, the input connection terminal 51, and the input terminal of the video display unit 42 are all conducted.

  If one of the two display units 16 having the above configuration is a display unit 16A and the other is a display unit 16B, in this embodiment, the input terminal 41 of the display unit 16A is connected to the control unit 4 via the HMD cable 5b. It is assumed that the output connection terminal 43 of the display unit 16A is connected to the input connection terminal 51 of the display unit 16B via the HMD cable 5c.

  When the HMD is configured as described above, the differential serial signal from the control unit 4 is input to the input terminal 41 of the display unit 16A via the HMD cable 5b. The differential serial signal is branched inside the display unit 16A, and one differential serial signal is supplied to the video display unit 42 of the display unit 16A. Thereby, in the display unit 16 </ b> A, the video is displayed by the video display unit 42.

  The other differential serial signal is supplied to the output connection terminal 43 and then input to the input connection terminal 51 of the display unit 16B via the HMD cable 5c. Therefore, in the display unit 16B, the differential serial signal is supplied from the input connection terminal 51 to the video display unit 42, and the video display unit 42 displays a video. Therefore, the observer can observe the images displayed on both the display units 16A and 16B with both eyes.

  FIG. 6 is a block diagram schematically showing another configuration of the HMD of this embodiment. According to the configuration of the display unit 16 of the present embodiment, as shown in FIG. 6, the input terminal 41 of the display unit 16B is connected to the control unit 4 via the HMD cable 5b, and the output connection terminal of the display unit 16B. 43 may be connected to the input connection terminal 51 of the display unit 16A via the HMD cable 5c to configure an HMD.

  That is, in this configuration, the differential serial signal from the control unit 4 is input to the input terminal 41 of the display unit 16B via the HMD cable 5b. The differential serial signal is branched inside the display unit 16B, and one differential serial signal is supplied to the video display unit 42 of the display unit 16B. Thereby, in the display unit 16B, the video is displayed by the video display unit 42.

  The other differential serial signal in the display unit 16B is supplied to the output connection terminal 43 and then input to the input connection terminal 51 of the display unit 16A via the HMD cable 5c. Therefore, in the display unit 16 </ b> A, the differential serial signal is supplied from the input connection terminal 51 to the video display unit 42, and a video is displayed by the video display unit 42. Therefore, the observer can observe the images displayed on both display units 16B and 16A with both eyes.

  As described above, the display unit 16A (16B) of the present embodiment displays the differential serial signal when the differential serial signal from the control unit 4 is input to the input terminal 41 of the display unit 16A (16B). Branched inside the unit 16A (16B), one differential serial signal is supplied to the video display unit 42 of the display unit 16A (16B), and the other differential serial signal is used for output of the display unit 16A (16B). When the differential serial signal is supplied from the control unit 4 to the input connection terminal 51 of the display unit 16A (16B) from the control unit 4 through the other display unit 16B (16A), the differential signal is supplied. The serial signal is supplied to the video display section 42 of the display unit 16A (16B). Thus, even when the differential serial signal from the control unit 4 is directly input to the input terminal 41 of the display unit 16A (16B), the input connection terminal 51 is connected via the other display unit 16B (16A). Can be displayed on both display units 16A and 16B, and an HMD capable of observing images with both eyes can be realized.

  Therefore, even if the display unit 16A (16B) is for a single eye, it can be easily expanded to a binocular combination with other display units 16 (16B and 16A). It is possible to avoid a decrease in efficiency, and hence a decrease in mass production of HMD. In particular, since the HMD capable of observing images with both eyes can be realized by combining two display units 16 having exactly the same configuration, the above effect is enormous.

  In addition, since the two display units 16 each include three terminals, that is, the input terminal 41, the input connection terminal 51, and the output connection terminal 43, whichever display unit 16 is used for the left eye, the right eye is used. Can also be used. Therefore, the mass production of the display unit 16 and thus the HMD is facilitated, and the cost can be reduced easily.

  As described above, in the present embodiment, an HMD capable of observing an image with both eyes can be realized by combining two display units 16 having exactly the same configuration. Therefore, the HMD of the present embodiment can be expressed as follows. It can be said. That is, the HMD of this embodiment includes a plurality of display units 16 that display video based on differential serial signals, and a control unit 4 that supplies a differential serial signal to any one of the display units 16. The display unit 16 includes two display units 16 of the present embodiment, and the input terminal 41 of one display unit 16 (for example, the display unit 16A) is connected to the control unit 4 via the HMD cable 5b. The output connection terminal 51 of the display unit 16 is connected to the input connection terminal 51 of the other display unit 16 (for example, the display unit 16B) via the HMD cable 5c.

[Embodiment 3]
The following will describe still another embodiment of the present invention with reference to the drawings. For convenience of explanation below, the same members as those in the first or second embodiment are denoted by the same member numbers, and description thereof is omitted.

  FIG. 7 is a block diagram showing a simplified configuration of the HMD of this embodiment. This HMD is obtained by connecting two display units 16 (fourth display unit) having the same configuration and a control unit 4 with a branch cable 5d. The branch cable 5 d is an HMD cable for supplying a differential serial signal from the control unit 4 to the plurality of display units 16 in parallel. Hereinafter, differences from the first embodiment will be described.

  The display unit 16 of this embodiment includes an input terminal 41 and a video display unit 42. The input terminal 41 is a connection terminal connected to the control unit 4 via the branch cable 5d, and one of a plurality of output ends of the branch cable 5d is connected to the input terminal 41. When the control unit 4 and the display unit 16 are connected via the branch cable 5d, the differential serial signal from the control unit 4 is input to the input terminal 41. The video display unit 42 displays video based on the differential serial signal input to the input terminal 41.

  In this way, two display units 16 having the input terminal 41 and the video display unit 42 are used (hereinafter also referred to as display units 16A and 16B), and the differential serial signal from the control unit 4 is sent via the branch cable 5d. By supplying the display units 16A and 16B in parallel, the display units 16A and 16B can display images based on the supplied differential serial signals. Accordingly, an HMD capable of observing images with both eyes can be configured, and an observer can observe images displayed on both display units 16A and 16B with both eyes.

  In addition, the display unit 16 is originally for a single eye arranged in front of one eye of the observer, but according to the configuration of the present embodiment, the two display units 16 can be combined and used for both eyes. Is possible. Thus, since the monocular display unit 16 can be easily expanded to both eyes, it is possible to avoid a decrease in manufacturing efficiency of the display unit 16 and a decrease in mass productivity of the HMD.

[Embodiment 4]
The following will describe still another embodiment of the present invention with reference to the drawings. For the convenience of explanation below, the same components as those in the first to third embodiments are denoted by the same member numbers, and the explanation thereof is omitted. In the present embodiment, a detailed configuration of the light source current adjustment circuit 49 applicable to the first to third embodiments will be described.

  FIGS. 8A and 8B are block diagrams showing a detailed configuration of the light source current adjustment circuit 49. In particular, FIG. 8A shows a case where an EEPROM 61 described later is provided on the control unit 4 side. FIG. 8B shows a case where the EEPROM 61 is provided on the display unit 16 side. The light source current adjustment circuit 49 according to the present embodiment includes the EEPROM 61, a DAC (D / A converter) 62, and a constant current circuit 63.

  The EEPROM 61 is storage means for storing adjustment data used for adjustment of video display. In this embodiment, data for adjusting the light intensity (brightness of emitted light, light intensity) of the light source 11 is used as the adjustment data. I remember it.

  When the adjustment data stored in the EEPROM 61 is input and set to the DAC 62, the DAC 62 is a signal based on the adjustment data and necessary for display (for example, voltages Vr, Vg, and Vb for each RGB). An output unit for outputting.

  The constant current circuit 63 is a drive unit that causes the light source 11 to emit light based on a signal output from the DAC 62. More specifically, the constant current circuit 63 converts the RGB voltages Vr, Vg, and Vb output from the DAC 62 into currents Ir, Ig, and Ib and supplies them to the light source 11 to emit light from the light source 11. Let

  By the way, as shown in FIG. 8A, when the EEPROM 61 is outside the display unit 16, that is, on the control unit 4 side, when the display unit 16 and the control unit 4 are combined to form an HMD, for each combination. Therefore, it is necessary to reset the adjustment data according to the display unit 16 to be used. In addition, when the adjustment data is written to the DAC 62 with the configuration of FIG. 8A, for example, the microprocessor 35 (see FIG. 4) reads the adjustment data stored in the EEPROM 61, writes the adjustment data to the DAC 62, and sets it. Need arises. However, when the communication between the control unit 4 and the display unit 16 is performed by the LVDS method using the differential serial signal as in the above-described embodiments, the communication direction is from the control unit 4 to the display unit 16. Since it is one-way, the microprocessor 35 cannot read the adjustment data of the EEPROM 61 in the display unit 16. Therefore, in the present embodiment, the EEPROM 61 is mounted on the display unit 16 side as shown in FIG. 8B (the light source current adjusting circuit 49 is configured to be completed within the display unit 16), and the above inconvenience is avoided. ing. Hereinafter, an actual sequence when the display unit 16 is configured as shown in FIG. 8B will be described.

  FIG. 9A is an explanatory diagram showing a sequence for writing adjustment data to the EEPROM 61 on the display unit 16 side, and FIG. 9B is an explanatory diagram showing a sequence for reading the adjustment data from the EEPROM 61 and writing it to the DAC 62. is there. 8A, 8B, 9A, and 9B, SCLK is a serial clock, SDAT is serial data, CS_EE is a chip select of EEPROM 61, PE is an EEPROM program enable, and SDAT ( DAC) represents serial data input to the DAC 62, and CS_DA represents DAC chip select. These all constitute a control signal transmitted from the microprocessor 35 of the control unit 4.

  The terminals SK, DI, CS, and PE of the EEPROM 61 indicate input terminals for SCLK, SDAT, CS_EE, and PE, respectively, and the terminal DO indicates an output terminal for serial data. Terminals SK, DI, and CS of the DAC 62 indicate input terminals for SCLK, SDAT (DAC), and CS_DA, respectively, and a terminal DI ′ indicates an input terminal for serial data output from the EEPROM 61 (that is, DI ′ = DO). . Note that EE indicates the same as EEPROM.

  First, when writing adjustment data in the EEPROM 61, the microprocessor 35 enables PE and CS_EE, and transmits data to be written in the EEPROM 61 by SDAT (DI). In this case, nothing is output from the EEPROM 61 as output SDAT (DO). On the other hand, the microprocessor 35 keeps CS_DA set to disabled. At this time, the data written to the EEPROM 61 includes, for example, a DAC address (setting channel), device-specific setting data, and DAC data as adjustment data. When the EEPROM 61 is mounted on the control unit 4 side as shown in FIG. 8A, only the DAC data is written in the EEPROM 61, but the DAC address (setting channel) and device-specific setting data are also written. It is necessary to keep in.

  Next, when setting adjustment data in the DAC 62, the microprocessor 35 disables PE, enables CS_EE, and transmits the address of the EEPROM 61 in SDAT (DI). Then, the EEPROM 61 transmits the read data as SDAT (DO). The read data includes the above-described DAC address (setting channel), device-specific setting data, and DAC data. The read data of the EEPROM 61 is devised so that it is in the same format as the data written to the DAC 62 as it is. Yes. At this timing, the microprocessor 35 sets CS_DA to be enabled so that the terminal DO of the EEPROM 61 and the terminal DI ′ of the DAC 62 are connected, so the data SDAT (DO) read from the EEPROM 61 is written to the DAC 62, The adjustment data is written and set to the DAC 62 normally.

  As described above, by mounting the EEPROM 61 on the display unit 16 side, adjustment data unique to each display unit 16 can be stored in the EEPROM 61 and can be written in the DAC 62. That is, the color adjustment data of the light source 11 stored in the EEPROM 61 can be written into the DAC 62 and set. Thereby, when the HMD is configured by combining the display unit 16 and the control unit 4, it is not necessary to reset adjustment data for each display unit 16 to be used. As a result, the production efficiency of HMD can be improved.

  Further, since each display unit 16 has its own adjustment data, even when only the display unit 16 is shipped, the adjustment of the display unit 16 to be used for each combination with the control unit 4 at the shipping destination. It is possible to realize an HMD that can display a good video based on data.

  In addition, since the EEPROM 61 is provided in the display unit 16, the adjustment is completed by each display unit 16, so that the process management is facilitated and the cost required for production can be reduced. Further, for example, when the EEPROM 61 is provided in the display unit 16 (no distinction between right and left) according to the second embodiment, any display units 16 and 16 are provided even when a monocular HMD and a binocular HMD are mixed. Can be combined to form a HMD for both eyes, so that management is easy and the cost required for production can be reduced.

  In the present embodiment, the adjustment data stored in the EEPROM 61 is data for adjusting the luminous intensity of the light source 11. Therefore, the adjustment data is read from the EEPROM 61 and written to the DAC 62. ) To the constant current circuit 63, and when the constant current circuit 63 supplies a drive current to the light source 11 based on the signal, the light source 11 can emit light with the luminous intensity of the emitted light adjusted, It becomes possible to adjust the brightness (luminance) of the image displayed on the display element 14.

  In addition, when the configuration of the light source current adjustment circuit 49 of this embodiment (the configuration in which the EEPROM 61 is mounted on the display unit 16 side) is applied to the HMD of the first to third embodiments, this HMD has the following configuration. Can do. That is, the HMD is connected to the control unit 4 via the HMD cable 5b (or branch cable 5d) in which the two display units 16 equipped with the EEPROM 61 and the DAC 62 are transmitted, and the control unit 4 A microprocessor 35 that transmits control signals to the EEPROM 61 and the DAC 62 is provided. Each display unit 16 reads the adjustment data written to the EEPROM 61 and reads the adjustment data written to the EEPROM 61 to the DAC 62 based on the control signal. In this configuration, writing and setting operations are performed.

  When the HMD is configured using the differential serial signal, the transmission of the differential serial signal is unidirectional from the control unit 4 to each display unit 16, so that the microprocessor 35 stores it in the EEPROM 61 in each display unit 16. As described above, the adjusted data cannot be read out. However, in the present embodiment, adjustment of each display unit 16 with respect to the EEPROM 61 is performed by transmitting a control signal from the control unit 4 to each display unit 16 via the HMD cable 5b or branch cable 5d that transmits a differential serial signal. Data writing and reading operations and writing and setting operations of the read adjustment data to the DAC 62 can be performed, respectively. Therefore, even if the communication from the control unit 4 to each display unit 16 is unidirectional, it is possible to adjust the display of the video based on the specific adjustment data for each display unit 16.

  In the present embodiment, the data for adjusting the light intensity of the light source 11 is taken as an example of the adjustment data used for adjusting the display of the video, and the case where the data is stored in the EEPROM 61 has been described. For example, data for register setting of the display element 14 (data for adjusting contrast, brightness, etc. in the display element 14) can be considered. Even in this case, since a signal based on the adjustment data is output from the output unit (for example, the DAC in the display element driving circuit 48), for example, the driving unit for driving the display element 14 is supplied from the output unit. By driving the display element 14 based on the received signal, an image can be displayed on the display element 14 with the contrast and brightness adjusted.

  Of course, the display unit 4 and the HMD can be configured by appropriately combining the configurations of the above-described embodiments.

  The display unit of the present invention can be applied not only to an HMD for a single eye (for video observation with a single eye) but also to an HMD for both eyes (for video observation with both eyes).

It is a block diagram which simplifies and shows the structure of HMD which concerns on one Embodiment of this invention. (A) is a top view which shows the whole structure of said HMD, FIG.2 (b) is a front view of HMD. It is sectional drawing which shows the schematic structure of the video display apparatus applied to the said HMD. It is a block diagram which shows the structure of the principal part of the control unit which comprises the said HMD, and the principal part of a display unit. It is a block diagram which simplifies and shows the structure of HMD which concerns on other embodiment of this invention. It is a block diagram which simplifies and shows the other structure of the said HMD. It is a block diagram which simplifies and shows the structure of HMD which concerns on further another embodiment of this invention. (A) And (b) is a block diagram which shows the detailed structure of the light source current adjustment circuit of HMD which concerns on further another embodiment of this invention, (a) provided EEPROM in the control unit side It is a block diagram of a light source current adjustment circuit, (b) is a block diagram of the light source current adjustment circuit which provided the said EEPROM in the display unit side. (A) is explanatory drawing which shows the sequence which writes adjustment data in EEPROM by the side of a display unit, (b) is explanatory drawing which shows the sequence which reads the said adjustment data from EEPROM, and writes it in DAC.

Explanation of symbols

4 Control unit 5b HMD cable 5c HMD cable 5d Branch cable 11 Light source 14 Display element 16 Display unit 16A Display unit 16B Display unit 35 Microprocessor (control unit)
41 Input Terminal 42 Video Display 43 Output Connection Terminal 51 Input Connection Terminal 61 EEPROM (Storage Unit)
62 DAC (output unit)
63 Constant current circuit (drive unit)

Claims (11)

A display unit that is arranged in front of one eye of an observer and displays an image based on a differential serial signal,
A connection terminal that can be connected via a cable to another display unit arranged in front of the other eye of the observer,
The connection terminal includes at least an output connection terminal capable of outputting a differential serial signal to another display unit, and an input connection terminal capable of inputting a differential serial signal from another display unit. A display unit characterized in that it is configured on the other hand. An input terminal to which a differential serial signal from the control unit is input;
A video display unit for displaying video based on the differential serial signal;
The connection terminal is composed of the output connection terminal,
The differential serial signal input from the control unit to the input terminal is branched inside the display unit,
One differential serial signal is supplied to the video display unit,
The display unit according to claim 1, wherein the other differential serial signal is supplied to the output connection terminal. A video display unit for displaying video based on the differential serial signal;
The connection terminal is composed of the input connection terminal.
The display unit according to claim 1, wherein the video display unit displays a video based on a differential serial signal input to the input connection terminal from the control unit via another display unit. An input terminal capable of inputting a differential serial signal from the control unit;
A video display unit for displaying video based on the differential serial signal;
The connection terminal is composed of the output connection terminal and the input connection terminal.
When the differential serial signal from the control unit is input to the input terminal, the differential serial signal is branched inside the display unit, and one differential serial signal is supplied to the video display unit, and the difference between the other is displayed. Dynamic serial signal is supplied to the output connection terminal,
2. The differential serial signal is supplied to the video display unit when a differential serial signal from a control unit is input to the input connection terminal via another display unit. The indicated display unit. A display unit that is arranged in front of one eye of an observer and displays an image based on a differential serial signal,
It has an input terminal that receives the differential serial signal from the control unit.
A display unit, wherein the input terminal is connected to one of a plurality of output ends of a branch cable for supplying a differential serial signal from the control unit in parallel with another display unit. Storage means for storing adjustment data used for adjustment of video display;
And an output unit for outputting a signal based on the adjustment data and necessary for display when the adjustment data stored in the storage unit is input and set. Item 6. The display unit according to any one of Items 1 to 5. A light source;
A display element that displays light by modulating light from a light source;
A drive unit that emits light from the light source based on the signal output from the output unit;
The display unit according to claim 6, wherein the adjustment data is data for adjusting a light intensity of a light source. A plurality of display units for displaying video based on differential serial signals;
A control unit for supplying a differential serial signal to any of the display units,
The plurality of display units includes the display unit according to claim 2 and the display unit according to claim 3.
An output connection terminal of the display unit according to claim 2 and an input connection terminal of the display unit according to claim 3 are connected via a cable. A plurality of display units for displaying video based on differential serial signals;
A control unit for supplying a differential serial signal to any of the display units,
The plurality of display units includes two display units according to claim 4,
The input terminal of one display unit is connected to the control unit via a cable,
The head mounted display, wherein the output connection terminal of the display unit is connected to the input connection terminal of the other display unit via a cable. Two display units according to claim 5;
A branch cable in which a plurality of output ends are respectively connected to input terminals of each display unit;
A head-mounted display, comprising: a control unit that supplies a differential serial signal to each display unit via a branch cable. The plurality of display units are
Storage means for storing adjustment data used for adjustment of video display;
When the adjustment data stored in the storage means is input and set, each output unit outputs a signal based on the adjustment data and necessary for display,
The control unit includes a control unit that transmits a control signal to the storage unit and the output unit via a cable that transmits a differential serial signal.
Each display unit performs an operation of writing adjustment data in the storage unit and an operation of reading out the adjustment data written in the storage unit, writing it in the output unit, and setting based on the control signal. Item 11. The head mounted display according to any one of Items 8 to 10.

Images