JP2013025330A - Operation display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation display device whose manufacturing cost is reduced by decreasing the number of components composing a touch panel and whose power consumption is reduced.SOLUTION: An operation display device 1 includes a liquid crystal panel 2 and a backlight part. Light-emitting elements 4 are disposed along four sides of a light guide plate 3. Reflection grooves 13 are formed on an incident surface 10 facing light-emitting surfaces of the light-emitting elements 4 to serve as luminous flux separation means. First light guides 15 and visible light cut filters 14 are disposed between the reflection grooves 13 and the liquid crystal panel 2 to guide near-infrared luminous flux 34 to a visible side of the liquid crystal panel 2. Second light guides 16 are fixed at positions facing the first light guides 15 with the liquid crystal panel 2 between the second light guides 16 and the first light guides 15. Light receiving elements 18 are disposed at positions facing the second light guides 16 with an image display area between the light receiving elements 18 and the second light guides 16 to configure a touch input device.

Description

  The present invention relates to a display device provided with input operation means.

Thin image display devices using liquid crystals are used for television receivers, computer terminal devices, advertising media, signs, and the like. The basic structure includes an image display unit and an electric circuit unit that incorporate a surface light source device and a liquid crystal panel, a structure unit that supports them, and an exterior unit. Recently, devices attracting attention are thin displays with a main body thickness of about several tens of millimeters, and long-life, high-color reproduction liquid crystal displays using LED (Light-emitting diode) light sources. In the structure of a surface light source device using an LED light source, a so-called sidelight type in which the LED light source is arranged on a side surface portion of the surface light source device, and surface light is emitted using a light guide plate imparted with angle conversion and diffusibility of light flux. It is common.
On the other hand, as devices that allow a user to perform an input operation such as a PC (personal computer) while viewing a display image, a keyboard and a mouse, and a touch panel that superimposes on the image and improves operability are widespread. Patent Document 1 discloses a structural example in which an optical touch panel is mounted on a liquid crystal image display device. When the light emitter connected to the power supply and control circuit repeats light emission at regular intervals, and the fingertip touches the input panel, the light detector that previously detected the infrared light of the light emitter will be in the undetected state, The position where the infrared light is blocked can be specified.

JP 05-035402 A

In order to add a touch panel function to a liquid crystal display in a conventional apparatus configuration, a light emitter, its driving power source and a control circuit are required. Therefore, an increase in the number of parts, cost, and power consumption are problems.
Therefore, an object of the present invention is to propose an operation display device that can reduce the number of parts constituting the touch panel, reduce the manufacturing cost, and reduce the power consumption.

  In order to solve the above-described problems, an apparatus according to the present invention is an operation display device including a display panel, a light source, a light guide member, and a detection unit that optically detects an operation on the display surface of the display panel. The light guide member is a first light guide member that guides light from the light source to the display panel, and a part of the light from the light source separated by a light beam separating unit provided on the first light guide member. A second light guide member is provided that guides in a direction along the display surface of the display panel. The detection means includes light receiving means for detecting light emitted from the second light guide member, and detects an operation position by detecting a light blocking state of light traveling in a direction along the display surface of the display panel.

  According to the present invention, the number of parts constituting the touch panel can be reduced, the manufacturing cost can be reduced, and the power consumption can be reduced.

FIG. 5 is a longitudinal sectional view showing a configuration example of an operation display device in order to explain the first embodiment of the present invention in conjunction with FIGS. 2 to 4. It is a top view of an operation display apparatus. It is a side view which shows the principal part of an operation display apparatus. It is a characteristic view of a light source. It is a longitudinal cross-sectional view of the operation display apparatus which concerns on 2nd Embodiment of this invention. It is a side view which shows the principal part of the operation display apparatus which concerns on 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the operation display apparatus which concerns on 3rd Embodiment of this invention. It is a side view which shows the principal part of the operation display apparatus which concerns on 3rd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the principal part of the operation display apparatus which concerns on 4th Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a longitudinal sectional view showing a configuration example of an operation display device according to the present invention. In the following description, it is assumed that the left side of FIG. 1 is the viewing direction of the display image, that is, the front and the front, and the upper side of FIG. 2 is a view when the operation display device is viewed from the front, and FIG. 3 is a side view (view A) of the main part when the operation display device is viewed from above, with some of the structural parts omitted. Show.
The operation display device 1 includes a liquid crystal panel 2 that is a display panel and a backlight unit described later, and is a thin device having a touch input function. The liquid crystal panel 2 has a structure in which a glass substrate on which electrical wiring is formed is faced to a glass substrate on which a color filter is formed, liquid crystal is sealed between both substrates, and an electric cable (described later) is connected to a terminal portion of the glass substrate. Have. The hard coat 2a is a scratch-preventing film bonded to the front surface of the liquid crystal panel 2, and is formed by coating a hard transparent resin. The light guide plate 3 disposed behind the liquid crystal panel 2 is a first light guide member that guides light from the light source to the liquid crystal panel 2 and has a substantially rectangular shape when viewed from a direction orthogonal to the display surface. In this example, it is an optical component processed into a plate shape with a transparent material (acrylic resin or the like). A plurality of light emitting elements 4 are arranged on the side of the light guide plate 3. Although an LED is used in this example, a linear light source such as a cold cathode lamp (CCFL) may be used. The LED light-emitting lens has a rectangular shape with a dimension of 4 mm (see dimension B in FIG. 3) × 3 mm, and emits white light. The light emitting lenses are arranged at almost equal intervals while facing the side surfaces of the four sides of the light guide plate 3.

The case 5 that houses the light guide plate 3 and the light emitting element 4 is a container that is sheet-metal processed with an aluminum alloy in this example, and has an opening on the front surface. The case 5 has a sealed structure so that light does not leak from portions other than the opening, and further has a function of radiating heat generated by the LEDs in the front direction and the rear. The frame 6 is a member that covers the periphery of the opening of the case 5 and has a frame shape having an opening. The end of the frame has a wall surface extending rearward, and houses the light guide plate 3 and the light emitting element 4 together with the case 5. A panel frame 7 provided in front of the frame 6 is a member obtained by processing a steel plate, has a frame shape having an opening, and covers the front four sides of the liquid crystal panel 2. By combining with the frame 6, both have a function of fixing the liquid crystal panel 2 between them. Moreover, the penetration part 7a formed in the panel frame 7 is an opening hole part through which a wiring member described later is inserted.
The cushioning material 8 is interposed between the frame 6 and the liquid crystal panel 2 and is an elastic material fixed with double-sided tape over four sides along the opening edge of the frame 6. The cushioning material 9 is an elastic material that is interposed between the panel frame 7 and the liquid crystal panel 2 and fixed with double-sided tape along the opening edge of the panel frame 7. The buffer materials 8 and 9 can be manufactured by cutting, for example, a silicone rubber sheet into a desired width. These buffer materials are support members that are arranged so as to sandwich the vicinity of the sealing region across the four sides of the liquid crystal panel 2 and support the peripheral portion of the liquid crystal panel 2. The buffer material 9 is provided with a plurality of through portions 9a at regular intervals.

  The incident surface 10 of the light guide plate 3 is provided on side surfaces of four sides of the light guide plate 3 when viewed from the front, and the light flux of the LED is incident thereon. This part is finished to a mirror surface. The plurality of diffuse reflection surfaces 11 are configured by an uneven pattern provided on the back side of the light guide plate 3. The pattern has a distribution in which the pattern is small near the light emitting element 4 and becomes gradually denser as the distance from the light emitting element 4 increases. Although not shown in the drawings, a visible light reflecting sheet is inserted into the gap between the light guide plate 3 and the case 5 to enhance the light utilization efficiency. The emission surface 12 is a front surface of the light guide plate 3 and has a function of emitting light emitted from the LEDs toward the liquid crystal panel 2. Although not shown, an optical sheet having a diffusibility and an optical sheet having a light collecting property are laminated on the surface.

  The reflection grooves 13 are cut portions formed at regular intervals along two sides of the light guide plate 3 (see the upper side and the left side in FIG. 2). 1 represents an angle formed between the back surface of the light guide plate 3 and the inclined surface of the reflection groove 13, and in this example, θ = 45 °. Further, the groove width A shown in FIG. 3 is 0.5 mm. The reflection groove 13 is formed at a position facing the light emitting surface of the light emitting element 4. A visible light cut filter 14 is provided at a position facing the reflection groove 13, and is disposed close to the emission surface 12 of the light guide plate 3. The first light guide 15 is a second light guide member that guides part of light from the light source in a direction along the display surface of the liquid crystal panel 2 together with a second light guide described later. The first light guide 15 is a light guide component interposed between the visible light cut filter 14 and the liquid crystal panel 2, and has a role of allowing light transmitted through the visible light cut filter 14 to enter the liquid crystal panel 2 so as not to leak to the surroundings. It has. In this example, the first light guide 15 and the visible light cut filter 14 are integrated and press-fitted and fixed in the holes of the frame 6. The second light guide 16 is a light guide component arranged at a position facing the first light guide 15 with the liquid crystal panel 2 interposed therebetween. A surface bonded and fixed to the liquid crystal panel 2 by the second light guide 16 is a light incident surface, and a surface orthogonal to the display screen is an emission surface. Since the through-hole 9a is formed in the buffer material 9 facing the emission surface, the light emitted from the second light guide 16 travels in a direction parallel to the display screen through the through-hole 9a. The reflecting surface 17 is an inclined surface provided on one surface constituting the second light guide 16 and has an inclination angle of 45 ° with respect to the surface of the liquid crystal panel 2. A light shielding film for preventing light leakage is formed on the reflection surface 17.

The light receiving element 18 constitutes a detecting means for optically detecting an operation on the display surface of the liquid crystal panel 2 and is provided on the back surface of the panel frame 7 in this example. Phototransistors as light receiving means are arranged along the opening edges of the two sides of the panel frame 7 (see the right side and the lower side in FIG. 2). The light receiving surface of each phototransistor is positioned so as to face the emission surface of the second light guide 16. That is, the light receiving element 18 is opposite to the second light guide 16 along each side opposed to the two sides of the light guide plate 3 (see the upper side and the left side in FIG. 2) across the display area of the display surface. Is arranged. Since the through-hole 9a is formed in the buffer material 9 at a position facing the light receiving surface, the light passing through the through-hole 9a reaches the light receiving surface. The substrate 19 on which the light receiving element 18 is mounted is a glass epoxy substrate on which printed wiring is formed. The connector 20 (see FIG. 2) is a mounting component connected to the printed wiring of the substrate 19 and is connected to a light receiving control circuit (not shown) and a power supply unit (not shown) using a cable 21.
A COF (Chip On Film) 22 is a flat cable for supplying a video signal from a drive circuit (not shown) to the liquid crystal panel 2, and an integrated circuit is mounted near the center thereof (not shown). A flexible substrate including a printed circuit is employed for the substrate 23 (see FIG. 1) on which the LEDs are mounted. The connector 24 is mounted on the substrate 23 and supplies power and signals from an LED drive circuit (not shown) to the substrate 23 via the cable 25.

Next, the arrows shown in FIGS. 1 and 2 will be described.
An incident light beam 30 indicated by an arrow in FIG. 1 schematically shows the direction of light taken into the light guide plate 3 from the light emitting element 4 through the incident surface 10. Further, the diffused light beam 31 indicates the direction of light diffusely reflected by the diffuse reflection surface 11 when the incident light beam 30 repeats reflection inside the light guide plate 3. The outgoing light beam 32 indicates the direction of light applied to the liquid crystal panel 2 and represents a light beam whose luminance inside the light guide plate 3 is substantially uniform over the front surface. As described above, the display quality can be improved by changing the characteristics of the irradiated light beam by the optical sheet (not shown) laminated on the surface of the light guide plate 3. The separated light beam 33 represents the direction of the light emitted from the light emitting element 4 and reflected by the reflection surface 13 a having an angle of 45 ° formed in the back of the reflection groove 13 without entering the light guide plate 3. That is, the light of the light emitting element 4 is branched by the reflecting surface 13a as the light beam separating means and is reflected in the front direction. The near-infrared light beam 34 indicates the direction of light that has passed through the visible light cut filter 14 in the separated light beam 33. This is transmitted through the periphery of the liquid crystal panel 2 from the first light guide 15, then enters the second light guide 16, and further undergoes an optical path change in a direction parallel to the display screen by the reflecting surface 17.
The position detection light beam 35 indicates the direction of light that travels along the surface of the liquid crystal panel 2 when the near-infrared light beam 34 emitted from the emission surface of the second light guide 16 passes through the through portion 9a of the buffer material 9. . FIG. 1 shows a state in which a member such as a finger 36 or a stylus, which is a light shield, is in contact with the liquid crystal panel 2 during an input operation on the touch panel. The blocking light beam 37 indicates the traveling direction of light when it is assumed that the light is not blocked by a light blocking object such as a finger. That is, in the figure, the direction of light that disappears is clearly indicated by an arrow when it is shielded by a finger 36 or the like. 2 shows a state where light emitted from the second light guide 16 disposed on the left side is blocked, and a blocked light beam 37b blocks light emitted from the second light guide 16 disposed on the upper side. It shows the state that was done.

Next, the detection mechanism of the touch panel in the present embodiment will be described.
FIG. 4 is a graph illustrating the wavelength distribution of the emitted light beam of the LED used in this embodiment. The horizontal axis indicates the wavelength λ in nm (nanometer) units, and the vertical axis indicates the relative irradiation intensity in arbitrary units. It can be seen that the LED of this example emits light over a wavelength range wider than the visible light range of 400 to 700 nm. The touch panel utilizes light in the wavelength region (700 to 850 nm) indicated by range D.
Part of the light emitted from the LED (light that is not used for the display image of the liquid crystal panel 2) reaches the visible light cut filter 14 as a separated light flux 33 in the reflection groove 13. The near-infrared light beam 34 that has passed through the first light guide 15 passes through the periphery of the liquid crystal panel 2 and enters the second light guide 16, and then travels in a direction parallel to the display screen at the reflecting surface 17. This near-infrared light beam passes through the penetrating portion 9a of the buffer material 9 and becomes a position detection light beam 35 used for the touch panel. The light receiving element 18 disposed facing the second light guide 16 always detects the position detection light beam 35 during normal operation, that is, when the LED is lit and the display image on the liquid crystal panel 2 is visible. For this reason, a light reception control circuit (not shown) electrically connected to the light receiving element 18 determines that a light blocking object such as a finger is not detected, that is, a state where there is no touch input. On the other hand, for example, when the finger 36 touches the liquid crystal panel 2 to block the position detection light beam 35, the light receiving element 18 at the position corresponding to the blocking light beams 37a and 37b (see FIG. 2) cannot detect the position detection light beam 35. . Therefore, the light reception control circuit (not shown) determines that there is a touch input. In this case, the planar position of the touch input is determined from the detection positions of the light receiving element 18 located on the right side and the light receiving element 18 located on the lower side in FIG. That is, the position where the light shielding object is detected can be specified as the X and Y coordinate values in the two-dimensional coordinates when the X axis is set in the horizontal direction in FIG. 2 and the Y axis is set in the vertical direction. Therefore, the operation position can be detected by detecting the light blocking state of the light traveling in the direction along the display surface of the liquid crystal panel 2.
In the above description, in the LED for using the position detection light beam 35 for touch input and the LED disposed along the other two sides of the light guide plate 3 where the reflection groove 13 is not provided, that is, the light amount distribution. Therefore, the balance of the amount of light used for the backlight unit is lost. Therefore, as a countermeasure, there is a method of maintaining the balance of light quantity by increasing the amount of current (current value) applied to the LEDs used for touch input. Or about LED utilized only for a backlight part, you may employ | adopt the method of affixing the light-shielding film of width 0.5mm on the entrance plane 10, and dimming.

The structural features of the operation display device described above are summarized as follows.
The light guide plate 3 and the light emitting element 4 are accommodated in the case 5 and the frame 6, and the light emitting elements 4 are arranged at regular intervals at positions facing the four sides of the light guide plate 3 so as to approach the incident surface 10.
The light-emitting element 4 has a rectangular shape (4 mm × 3 mm) and a white LED having a wavelength range of 350 to 850 nm.
-The incident surfaces 10 on the four sides of the light guide plate 3 are mirror-finished, the diffuse reflection surface 11 is formed on the back surface, and a visible light reflection sheet (not shown) is laminated. Further, an optical sheet is laminated on the emission surface 12.
Use the frame 6 and the panel frame 7 to sandwich the periphery of the liquid crystal panel 2 with the cushioning materials 8 and 9 interposed. Further, the surface of the liquid crystal panel 2 is subjected to a hard coat treatment.
-Reflective grooves 13 having a predetermined width (0.5 mm) are formed at regular intervals on the two sides of the light guide plate 3 (upper side and left side as viewed from the front side) from the incident surface 10 to the emission surface 12. The reflection groove 13 is formed at a position facing the light emitting lens of the LED, and the reflection groove 13 has a bottom surface (slope) that forms an angle of 45 ° with respect to the diffuse reflection surface 11.
The visible light cut filter 14 and the first light guide 15 are disposed at a position facing the reflection groove 13, approached to the emission surface 12, and caulked and fixed to the penetrating portion of the frame 6. The other end face of the first light guide 15 is brought into close contact with the peripheral portion of the liquid crystal panel 2.
The second light guide 16 is disposed at a position facing the first light guide 15 with the liquid crystal panel 2 interposed therebetween. The second light guide 16 is provided with a reflection surface 17 having a 45 ° angle provided with a light shielding film, a portion in contact with the liquid crystal panel 2 as an incident surface, and a surface orthogonal to the image display surface as an output surface.
The light receiving elements 18 are arranged on two sides (a lower side and a right side when viewed from the front side) facing the emission surface of the second light guide 16 with the image display area interposed therebetween. Furthermore, the buffer material 9 is provided with a plurality of through portions 9 a at positions facing the light exit surface of the second light guide 16 and the light receiving element 18.
A part of the light emitted by the LED in the wide wavelength range is extracted in the front direction by the reflection surface 13a, and passes through the visible light cut filter 14, the first light guide 15, the liquid crystal panel 2, and the second light guide 16, It led to the image display surface.
The position coordinates of the light shielding object (detection target) can be detected from the light receiving element 18 at the position where the position detection light beam 35 is shielded by a touch input operation.

According to the first embodiment, the following effects can be obtained.
1. Since the backlight part which irradiates light uniformly from the back side of the liquid crystal panel 2 can be constituted, a display image with high uniformity can be obtained.
2. Since the dedicated light emitter required for the touch panel is no longer required, the number of parts, cost, and power consumption can be reduced.
3. A touch panel capable of highly reliable touch input can be configured. This is due to the arrangement of the light receiving element 18 facing the emission surface of the second light guide 16 and the hard coat 2a applied to the surface of the liquid crystal panel 2.
In the present embodiment, a configuration example in which a plurality of LEDs are arranged on the four sides of the side surface of the light guide plate 3 has been described. However, even if LEDs are arranged only on two adjacent sides, a light beam for touch operation can be extracted. it can. Furthermore, the reflection grooves 13 are arranged on the upper side and the left side and the light receiving elements 18 are arranged on the lower side and the right side as viewed from the front, but the arrangement is not limited to this. The same effect can be obtained by a configuration in which the component arrangement is changed in the vertical direction or the horizontal direction, for example, a configuration in which the reflection grooves 13 are arranged on the upper side and the right side and the light receiving element 18 is arranged on the lower side and the left side. Moreover, the arrangement of parts in the front-rear direction may be interchanged with respect to the arrangement of the visible light cut filter 14 and the first light guide 15. In this case, the light beam incident on the first light guide 15 is guided to the liquid crystal panel 2 via the visible light cut filter 14, but the same effect can be obtained. Such changes and modifications of the configuration are the same in the embodiments described below.

(Second Embodiment)
Next, an operation display device according to a second embodiment of the present invention will be described. In addition, about the component which has the function similar to the case of 1st Embodiment, detailed description is abbreviate | omitted by using the code | symbol already used. The method of omitting such description is the same in other embodiments described later.
FIG. 5 is a longitudinal sectional view of the operation display device, and the left side of the figure is the front and the front. FIG. 6 is a side view (view B) of the main part of the operation display device as viewed from above.
The light guide plate 53 of the operation indicating device 51 is an optical component processed into a substantially rectangular plate shape using a transparent acrylic resin. The case 55 is a container that houses the light guide plate 53 and the light emitting element 4. The case 55 has an opening on the front surface, and has a sealed structure except for the opening. The case 55 has a function of radiating heat generated by the light emitting element 4 backward. The convex portion 55 a is a portion that is drawn forward at the back surface portion of the case 55, and has a role of holding the light guide plate 53. The panel frame 57 has a frame shape having an opening by sheet metal processing, and is a member that covers the four front sides of the liquid crystal panel 2. The through hole 57a is an opening for allowing a wiring component described later to pass therethrough. The cushioning material 59 is made of an elastic material fixed with a double-sided tape along the opening of the panel frame 57, and is disposed so as to sandwich the vicinity of the four regions of the liquid crystal panel 2 together with the cushioning material 8. Note that no through portion is formed in the buffer material 59.

The substrate 23 on which the light emitting element 4 is mounted is located between the case 55 and the back surface of the light guide plate 53, and is attached to a position near the outer peripheral edge on the front surface of the case 55 as shown in FIG. The light from the light emitting element 4 is incident on the incident surface 60 along the four sides on the back surface of the light guide plate 53 and finished to a mirror surface. The inclined surfaces 63 are formed on the four sides of the light guide plate 53. The inclined angle θ with respect to the incident surface 60 is 45 °, and a visible light reflecting film is laminated on the surface. The second light guide 66 is a light guide component disposed at a position facing the first light guide 15 with the liquid crystal panel 2 interposed therebetween, and is fitted into a through hole formed in the panel frame 57 and fixed with an adhesive. Yes. The surface in contact with the liquid crystal panel 2 in the second light guide 66 is the light incident surface. A part of the second light guide 66 protrudes from the panel frame 57 to the front side, and an emission surface orthogonal to the display screen is formed. The reflecting surface 67 is an inclined surface having an angle of 45 ° formed in a portion of the second light guide 66 protruding from the panel frame 57 to the front side, and a light shielding film is formed on the surface in order to prevent light leakage.
The guide ribs 68 are protrusions having a thickness of 1 mm formed on the slopes 63 on the two sides of the light guide plate 53 (the upper side and the left side when viewed from the front side), and are formed integrally with the light guide plate 53 by resin molding. As shown in FIG. 6, the guide rib 68 is included in the width of the light emitting surface of the light emitting element 4 and is shifted by a distance of 1 mm (see dimension C) from the center, but with respect to the visible light cut filter 14. Are aligned so that their centers are opposed to each other. Further, a visible light reflecting film is laminated on the guide rib 68 except for the surface facing the visible light cut filter 14.

Next, the detection mechanism of the touch panel will be described.
The characteristics of the LED used are the same as those in the first embodiment, and the light flux in the range D shown in FIG. 4 is used for detecting the input operation. Part of the light emitted from the LED (light that is not used for the display image of the liquid crystal panel 2) is incident on the inside from the incident surface 60 of the light guide plate 53 and guided to the visible light cut filter 14 as the separated light flux 33 by the guide rib 68. . The near-infrared light beam 34 that has passed through the first light guide 15 passes through the periphery of the liquid crystal panel 2 and enters the second light guide 66, and travels in a direction parallel to the display screen at the reflection surface 67. This is the position detection light beam 35 used for the touch panel. Since the principle of specifying the X and Y coordinates to be detected by subsequent touch input is the same as in the first embodiment, the description thereof is omitted.
In the backlight unit that irradiates the liquid crystal panel 2 from the back surface, the light beam 30 entering the light guide plate 53 from the incident surface 60 is reflected by the inclined surface 63. While the reflection is repeated, the light hitting the diffuse reflection surface 11 exits from the emission surface 12 and illuminates the liquid crystal panel 2 as in the first embodiment.
In the present embodiment, as shown in FIG. 6, the light amount taken into the guide rib 68 is reduced by shifting the centers of the light emitting element 4 and the guide rib 68. Thereby, the luminance balance of the emitted light flux 32 is improved between the LED used for touch input and the LED used only for the backlight.

The structural features of the second embodiment that are different from the first embodiment are summarized as follows.
The light emitting elements 4 are arranged at regular intervals in the vicinity of the four sides on the back side of the light guide plate 53 so as to approach the incident surface 60.
The incident surface 60 of the light guide plate 53 is mirror-finished, and a visible light reflecting film is formed on the inclined surface 63 having an angle of 45 ° formed on the four sides.
The guide ribs 68 having a width of 1 mm are formed at regular intervals on the two sides of the light guide plate 53 (upper side and left side when viewed from the front). With respect to the arrangement of the guide rib 68, the centers are shifted by a predetermined distance (1 mm) at a position facing the light emitting lens of the light emitting element 4, and a visible light reflecting film is formed on the guide rib 68 except for the front side surface.
The second light guide 66 is disposed at a position facing the first light guide 15 with the liquid crystal panel 2 interposed therebetween. Further, the second light guide 66 is formed with a reflection surface 67 having an angle of 45 ° provided with a light-shielding film. Form a surface.
A part of light from the LED in a wide wavelength range is taken out to the front side by the guide rib 68 provided on the slope 63. This light is guided to the image display surface as a light beam used for the touch panel via the visible light cut filter 14, the first light guide 15, the peripheral portion of the liquid crystal panel 2, and the second light guide 66.
According to the second embodiment, the following effects are obtained in addition to the effects of the first embodiment.
By intentionally shifting the guide rib 68 for extracting the light from the LED from the center position of the light emitting lens of the LED, the light flux to be captured is limited, so that the brightness of the display image can be made uniform. This is because the difference between the luminance of the LED used for the touch input as the backlight and the luminance of the LED used only for the backlight is reduced.
In addition, in the embodiment in which the LEDs are not arranged on the four sides of the case as viewed from the front, but are arranged only on the two adjacent sides, the slopes and incident surfaces on the two sides where the LEDs are not arranged are unnecessary. Further, the guide rib and the light receiving element can be arbitrarily arranged according to the specification.

(Third embodiment)
Next, a third embodiment of the present invention will be described.
FIG. 7 is a longitudinal sectional view of the operation display device, and the left side of the figure is the front side. FIG. 8 is a main part side view (view C) of the operation display device as viewed from above. Hereinafter, differences from the second embodiment will be mainly described.
A light guide hole 84 is formed in the light guide plate 82 of the operation display device 81 along the front-rear direction. The light guide hole 84 is a hole having a diameter of about 1 mm formed at a position facing the light emitting surface of the light emitting element 4 and penetrates from the incident surface 60 of the light guide plate 82 to the inclined surface 83. The first light guide 85 is a light guide component interposed between the inclined surface 83 and the visible light cut filter 14, and allows the light that has passed through the light guide plate 82 to enter the visible light cut filter 14 without leaking to the surroundings. The first light guide 85 and the visible light cut filter 14 are integrated and press-fitted and fixed in a hole formed in the frame 6.

Next, the detection mechanism of the touch panel will be described.
Part of the light from the light emitting element 4 (light not used for the display image of the liquid crystal panel 2) passes through the light guide hole 84 and is guided to the first light guide 85 as the separated light flux 33. Near-infrared light that has passed through the visible light cut filter 14 and then has passed through the peripheral portion of the liquid crystal panel 2 enters the second light guide 66. Near-infrared light whose optical path is changed by 90 ° at the reflecting surface 67 is directed in a direction parallel to the display screen, and becomes a position detection light beam 35 used for the touch panel. Since the principle of specifying the X and Y coordinates to be detected by subsequent touch input is the same as in the first embodiment, the description thereof is omitted.
In the backlight unit that irradiates the liquid crystal panel 2 from the back surface, the light beam 30 entering the light guide plate 82 from the incident surface 60 is reflected by the inclined surface 83. While the reflection is repeated, the light hitting the diffuse reflection surface 11 exits from the emission surface 12 and irradiates the liquid crystal panel 2.

The structural features of the third embodiment that are different from those of the second embodiment are summarized as follows.
A light guide hole 84 having a diameter of 1 mm is continuously formed at regular intervals along the two sides of the light guide plate 82 (upper side and left side when viewed from the front) and facing the light emitting lens of the LED.
The first light guide 85 is disposed between the liquid crystal panel 2 and the light guide plate 82 at a position facing the light guide hole 84.
According to the third embodiment, in addition to the effects of the second embodiment, a part of the light from the LED is taken out from the light guide hole 84 in the front direction, thereby efficiently using the light from the LED for touch input. Detection can be performed.

(Fourth embodiment)
Next, a third embodiment of the present invention will be described.
FIG. 9 is a longitudinal sectional view showing the main part of the operation display device, and the left side of the figure is the front side. Hereinafter, differences from the third embodiment will be mainly described.
The frame 92 of the operation display device 91 has a frame end portion that covers the periphery of the opening portion of the case 55 and a wall surface extending behind the frame end portion, and a through hole portion 92a of the first light guide is formed. A panel frame 93 covering the four front sides of the liquid crystal panel 2 sandwiches the liquid crystal panel 2 together with the frame 92, and has a through hole portion 93 a of the second light guide 66.
The first light guide 94 is a light guide component interposed between the visible light cut filter 95 and the light guide plate 82, and has a crank shape when viewed from the side. The rear end portion of the first light guide 94 is disposed in close contact with the slope 83 at a position facing the light guide hole 84. Total reflection surfaces 94a and 94b are formed at two bent portions, respectively. The portion near the front end is press-fitted and fixed in the through hole 92 a of the frame 92. The first light guide 94 is covered with a visible light shielding film made of a metal material except for the entrance surface and the exit surface, and the visible light cut filter 95 integrated with the front end faces the second light guide 66. It is in close contact with each other.

Next, the detection mechanism of the touch panel will be described.
Part of the light from the light emitting element 4 (light not used for the display image of the liquid crystal panel 2) passes through the light guide hole 84 and is guided to the first light guide 94 as the separated light flux 33. The light that has undergone a 90 ° optical path change at the first total reflection surface 94a and travels forward by the reflection at the next total reflection surface 94b passes through the visible light cut filter 95 and is converted into near-infrared light as the second light guide 66. Is incident on. The light traveling in the direction parallel to the display screen due to the reflection on the reflection surface 67 becomes a position detection light beam 35 used for the touch panel. Since the principle of specifying the X and Y coordinates to be detected by subsequent touch input is the same as in the first embodiment, the description thereof is omitted.

In the fourth embodiment, the structural features different from the third embodiment are summarized as follows.
The first light guide 94 has total reflection surfaces 94a and 94b at two bent portions, and the rear end portion is in close contact with the inclined surface 83 at a position facing the light guide hole 84, and the front end portion A visible light cut filter 95 is disposed.
A part of the light from the LED passes through the light guide hole 84 and becomes a light flux used for the touch panel via the first light guide 94, the visible light cut filter 95, and the second light guide 66. The first light guide 94 is disposed through a through hole portion 92 a formed in the frame 92 and bypasses the peripheral portion of the liquid crystal panel 2, so that light does not pass through the peripheral portion of the liquid crystal panel 2.
According to the fourth embodiment, the following effects are obtained in addition to the effects of the third embodiment.
The light that becomes the light flux for touch input does not pass through the liquid crystal panel 2 along the way, so that light loss is reduced. Therefore, the incident light flux used for touch input can be reduced, which contributes to relatively improving the luminance of the backlight.

1, 51, 81, 91 Operation display device 2 Liquid crystal panel 3, 53, 82 Light guide plate 4 Light emitting element 8, 9 Buffer material 10 Incident surface 11 Diffuse reflection surface 12 Output surface 13 Reflection groove 14, 95 Visible light cut filter 15, 85, 94 First light guide 16 Second light guide 17 Reflecting surface 18 Light receiving element

Claims (10)

An operation display device comprising a display panel, a light source and a light guide member, and a detection means for optically detecting an operation on the display surface of the display panel,
The light guide member includes a first light guide member that guides light from the light source to the display panel, and a part of light from the light source separated by a light beam separating unit provided on the first light guide member. A second light guide member that leads in a direction along the display surface of
The detection means includes light receiving means for detecting light emitted from the second light guide member, and detects an operation position by detecting a light shielding state of light traveling in a direction along the display surface of the display panel. An operation display device characterized by the above. The light source and the first light guide member constitute a backlight part of the display panel,
The first light guide member has an exit surface facing the display panel, a diffuse reflection surface facing the exit surface, and an entrance surface facing the light source, and the light beam separating means is The operation display device according to claim 1, wherein the operation display device is formed by an inclined surface. Further equipped with a visible light cut filter,
The light emitted from the light source branches off at the slope, and one of the lights enters the first light guide member, and the other light enters the second light guide member and passes through the visible light cut filter. 3. The operation display device according to claim 2, wherein near infrared light is detected by the light receiving means. The light source has a plurality of light emitting elements,
4. The operation display device according to claim 2, wherein the first light guide member is formed with a reflective groove having a slope facing each of the plurality of light emitting elements. 5.   A direction along the display surface by providing a reflection surface on the second light guide member and reflecting the light incident on the second light guide member and transmitted through the peripheral portion of the display panel by the reflection surface. The operation display device according to claim 1, wherein the operation display device is changed to:   2. A support member that supports a peripheral portion of the display panel is provided, and the support member is formed with a penetrating portion that allows light emitted from the second light guide member to pass therethrough. The operation display device according to claim 5.   3. The operation display device according to claim 2, wherein a part of light incident on the first light guide member from the light source is transmitted through the inclined surface and guided to the second light guide member.   The operation display device according to claim 2, wherein a hole is formed in the first light guide member, and light from the light source passes through the hole and enters the second light guide member.   The second light guide member has a plurality of total reflection surfaces, and the light incident on the second light guide member and reflected by the plurality of total reflection surfaces does not pass through the peripheral portion of the display panel. 5. The operation display device according to claim 1, wherein the light is emitted from the second light guide member toward the light receiving unit. The first light guide member has a rectangular shape when viewed from a direction orthogonal to the display surface, and an incident surface for the light source is formed on at least two adjacent sides thereof.
The light receiving means is disposed on the opposite side of the second light guide member along each side opposed to the two sides of the first light guide member across the display area of the display surface. The operation display device according to claim 1, wherein the operation display device is a display device.

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