custom search form not working on custom taxonomy template

I am using custom search from on taxonomy template like my custom taxonomy product_category and i have created template taxonomy-product_category.php and i have created a custom from on this file when i click on search and submit its redirect me page not found page .. i don't know how to fix it . can anyone please help ..

i am using this form .

<form method="get" action="http://example.com/product-category/area-scan-camera/" class="form-horizontal">

        <div class="form-group text-muted">
                                            <label class="col-sm-4 control-label">Interface :</label>
            <div class="col-sm-8 mt8">
                <ul class="list-inline">
                                                <li>
                            <label class="commonradio">
                                <input type="radio" value="gige" name="sub_category">
                                <span></span>
                                <strong>GigE</strong>
                            </label>
                        </li>
                                                <li>
                            <label class="commonradio">
                                <input type="radio" value="usb2-0" name="sub_category">
                                <span></span>
                                <strong>USB2.0</strong>
                            </label>
                        </li>
                                                <li>
                            <label class="commonradio">
                                <input type="radio" value="usb3-0" name="sub_category">
                                <span></span>
                                <strong>USB3.0</strong>
                            </label>
                        </li>
                                                <li>
                            <label class="commonradio">
                                <input type="radio" value="firewire" name="sub_category">
                                <span></span>
                                <strong>Firewire</strong>
                            </label>
                        </li>
                                                <li>
                            <label class="commonradio">
                                <input type="radio" value="cameralink" name="sub_category">
                                <span></span>
                                <strong>CameraLink</strong>
                            </label>
                        </li>
                                                <li>
                            <label class="commonradio">
                                <input type="radio" value="coaxpress" name="sub_category">
                                <span></span>
                                <strong>CoaXPress</strong>
                            </label>
                        </li>
                                        </ul>
            </div>
                        </div>
                        <div class="form-group text-muted">
                <label class="col-sm-4 control-label">SENSOR Color:</label>
                <div class="col-sm-8 mt8">
                    <ul class="list-inline">
                        <li>
                            <label class="commonradio">
                                <input type="radio" value="color" name="_vital_area_senser_color">
                                <span></span>
                                <strong>COLOR</strong>
                            </label>
                        </li>
                        <li>
                            <label class="commonradio">
                                <input type="radio" value="monochrome" name="_vital_area_senser_color">
                                <span></span>
                                <strong>MONOCHROME</strong>
                            </label>
                        </li>
                    </ul>
                </div>
            </div>

            <div class="form-group text-muted">
                <label class="col-sm-4 control-label">SENSOR Type:</label>
                <div class="col-sm-8 mt8">
                    <ul class="list-inline">
                        <li>
                            <label class="commonradio">
                                <input type="radio" value="ccd" name="_vital_area_senser_type">
                                <span></span>
                                <strong>CCD</strong>
                            </label>
                        </li>
                        <li>
                            <label class="commonradio">
                                <input type="radio" value="cmos" name="_vital_area_senser_type">
                                <span></span>
                                <strong>CMOS</strong>
                            </label>
                        </li>
                    </ul>
                </div>
            </div>
                                    <div class="form-group text-muted">
                <label class="col-sm-4 control-label">OPTICAL CLASS (Sensor Size) :</label>
                <div class="col-sm-2">
                    <select class="form-control">
                        <option value="all">All</option>
                        <option value="1/4">1/4"</option>
                        <option value="1/3">1/3"</option>
                    </select>
                </div>
            </div>

            <div class="form-group text-muted">
                <label class="col-sm-4 control-label">FRAME RATE :</label>
                <div class="col-sm-2">
                    <select name="frame_rate" class="form-control">
                        <option value="&lt;10">&lt; 10fps</option>
                        <option value="&gt;10">&gt; 10fps</option>
                        <option value="&gt;20">&gt; 20fps</option>
                        <option value="&gt;40">&gt; 40fps</option>
                        <option value="&gt;60">&gt; 60fps</option>
                        <option value="&gt;80">&gt; 80fps</option>
                        <option value="&gt;100">&gt; 100fps</option>
                    </select>
                </div>
            </div>

            <div class="form-group text-muted">
                <label class="col-sm-4 control-label">RESOLUTION CLASS (Mega Pixel) :</label>
                <div class="col-sm-2">
                    <select name="resolution" class="form-control">
                        <option value="&lt;1">&lt; 1MP</option>
                        <option value="&gt;1-2">&gt; 1-2MP</option>
                        <option value="&gt;2-4">&gt; 2-4MP</option>
                        <option value="&gt;4-5">&gt; 4-5MP</option>
                        <option value="&gt;5-8">&gt; 5-8MP</option>
                        <option value="&gt;8-10">&gt; 8-10MP</option>
                        <option value="&gt;10-20">&gt; 10-20MP</option>
                        <option value="&gt;20">&gt; 20MP</option>
                    </select>
                </div>
            </div>

            <div class="form-group text-muted">
                <label class="col-sm-4 control-label">FEATURE :</label>
                <div class="col-sm-2">
                    <select name="feature" class="form-control">
                        <option value="">-- Select Feature --</option>
                        <option value="poe">PoE</option>
                    </select>
                </div>
            </div>

        <input type="hidden" value="area-scan-camera" name="category_name">
        <div class="form-group mt30">
            <div class="col-sm-offset-4 col-sm-2">
                <input type="submit" value="Search" class="btn btn-info btn-common btn-lg btn-block" name="custom_search_form">
            </div>
        </div>
    </form>

Thanks