JPH04430Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a touch panel using a light source and a light sensor.

Conventional technology There are touch panels that use contact pressure and those that use light.

Figure 3 is a plan view illustrating the outline of a touch panel using a light source and optical sensor.
Reference numeral 2 denotes a frame disposed on one surface of the substrate 1, and as shown in FIG. 4, a wall 2a is provided from the open end toward the inside of the frame. A plurality of light sources 3 are arranged along adjacent inner walls of the frame 2 with their optical axes directed inward to the frame 2 to form light source groups 3a and 3b. Reference numeral 4 denotes an optical sensor, which is arranged on the optical axis of each light source 3 on an inner wall facing the inner wall on which the light source groups 3a and 3b of the frame body 2 are arranged, and constitutes the sensor groups 4a and 4b. 5a,
5b indicates the optical axis formed by each light source group and sensor group.

This touch panel is used by being attached to a display surface of a cathode ray tube display or the like. When a fingertip or the like is inserted into the substrate 1 at the coordinates x and y in FIG. 1, for example, the light rays passing through this area are blocked, and the light rays passing through other areas are directly irradiated onto the optical sensor.

Therefore, the coordinates x and y can be known from the light detection states of the optical sensor groups 4a and 4b.

Problems that the invention aims to solve By the way, since the light emitted from the light source is diffused, a means for regulating the diffusion of light is provided either on the light source 3 itself or in front of the light source 3, but it is not possible to obtain completely straight light. First, the array pitch of the optical sensor must be set so that it is not affected by adjacent light sources.
As the size of the touch panel increases, a decrease in resolution is inevitable.

Means for solving the problems This invention was proposed in view of the above problems.
By arranging the light source and the optical sensor in front of each other so that the light emitted from one light source is transmitted to the opposing optical sensor and blocked to the adjacent optical sensor, the polarization axis is oriented. It is a problem solved.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The difference from Figure 3 in the figure is light source group 3.
The only difference is that a polarizing filter b is arranged in front of the optical sensor groups 4a and 4b.

The polarizing filter b is configured to transmit light to the light source group 3a and the optical sensor 4 facing each other.
Polarizing filters 6a and 6b whose polarization axes differ by 90 degrees are alternately arranged in the arrangement direction of the optical sensor group 3b and the optical sensor groups 4a and 4b.

The operation of this touch panel is the same as that of the touch panel shown in FIG. 3, but as shown in FIG. 2, light emitted from one light source 3 passes through a polarizing filter 6a and hits a group of optical sensors 4 facing each other.

The light emitted from the light source 3 is condensed for the time being, but as the distance increases, it becomes diffused and comes to hit not only the optical sensor 4 on the optical axis but also the adjacent optical sensors 4', 4'.

In this case, since the polarization axis coincides with the polarization filter 6a in front of the optical sensor 4 on the optical axis, the light from the light source 3 passes through the filter 6a. On the other hand, since the polarizing filters 6b, 6b in front of the adjacent optical sensors 4', 4' have different polarization axes, light transmission is blocked, and together with the oblique incidence, the amount of light incident on the optical sensors 4', 4' becomes extremely small. . The light from the light source 3 is transmitted to the optical sensors 4'', 4'' further outward from the optical sensors 4', 4', but because the angle of incidence is large, the amount of incident light is small, and the sensor output is measured by a level comparator. The effect can be eliminated by means such as taking it out through a filter.

Effects of the invention As described above, according to the invention, even if the diffused light from the light source illuminates the desired sensor, the adjacent sensor, and the adjacent sensor, it is blocked by the combination of polarizing filters, so the touch panel can be made larger. The resolution can be improved because the arrangement pitch of the light source and optical sensor can be reduced, for example, the effective area can be reduced.
For a size of 192 mm x 96 mm, the arrangement pitch of the light source and optical sensor, which was previously limited to 6 mm, can now be arranged at 3 mm intervals, improving resolution.

[Brief explanation of drawings]

FIG. 1 is a partial plan cross-sectional view showing an embodiment of the present invention;
FIG. 2 is an explanatory diagram for explaining the operation of the present invention, FIG. 3 is a plan view showing an example of a touch panel, and FIG. 4 is a sectional view taken along line A-A in FIG. 3... Light source, 3a, 3b... Light source group, 4... Optical sensor, 4a, 4b... Optical sensor group, 6, 6a,
6b...Polarizing filter.

Claims (1)

[Scope of utility model registration request] Two sets of a light source group in which a plurality of light sources are arranged in a straight line, and a light sensor group in which a plurality of optical sensors each receiving light from each light source of the light source group are arranged in a straight line,
In a touch panel in which the optical axes of each light source group are arranged so as to intersect, and the output of a light sensor corresponding to the position of a light shield inserted in an area surrounded by the light source group and the light sensor group is obtained, the front surface of the light source is Polarizing filters are arranged in a direction whose polarizing axes are perpendicular to the polarizing axis of the polarizing filter in front of the adjacent light source, and light from the light source corresponding to the optical sensor is transmitted in front of each optical sensor, A touch panel characterized by having a polarizing filter arranged to block light from adjacent light sources.