An invention made within the area of activity of the employer by an employee who is not obliged as part of his work to engage in inventive activity, and who has done so by using information or means accessible to him by reason of his employment, shall belong to the employee, except where the employer informs him of his interest in the invention in accordance with the provisions of Article 16 of this Law. 11. The employee who makes an invention within the meaning of Article 10 of this Law shall immediately declare it to the employer in accordance with the provisions of Articles 12 and 16 of this Law. Where there are two or more inventors, a joint declaration may be made by all or only some of them. 12. This declaration shall include information concerning: — the subject matter of the invention and planned applications, — the circumstances in which the invention was made. The declaration shall be accompanied by a description of the invention. That description shall give an account of: — the problem that the employee set himself, due regard being had where applicable of the prior art; — the solution reached by him; — the manner in which the invention was made, accompanied where appropriate by drawings. 13. Where the employer declares his interest in accordance with the provisions of Article 10 of this Law, the right to the patent shall be regarded as having belonged to him from the outset. The employee-inventor shall be entitled to equitable compensation, due regard being had to the economic value of the invention and any profit accruing to the employer from its exploitation. In the absence of agreement between the parties on the amount, the compensation shall be set by the competent court. Any contractual clause less favourable to the employee inventor than the provisions of this Article shall be null and void. The period accorded to the employer within which to claim ownership of the invention shall be four months, unless otherwise agreed by the parties. Any agreement shall be in writing and shall follow the declaration. 14. Where the employee’s declaration does not conform to the provisions of Article 12 of this Law, the employer shall notify the person concerned of the additional information that has to be provided. That notification shall occur within two months following the date of receipt of the employee’s declaration, failing which the declaration shall be considered accepted. 15. The period for the employer’s declaration claiming ownership of the invention as provided in Article 13 of this Law shall run from the date of receipt by the employer of the invention declaration containing the information specified in Article 12 of this Law or, in the event of a justified request for additional information, from the date on which the requested additional information is provided. page 4/23